JP2018168287A - Long fiber-reinforced polyamide resin composition pellet and molded product of the same - Google Patents

Abstract

To provide a long fiber-reinforced polyamide resin composition pellet excellent in flowability at the time of molding and mechanical characteristics, and to provide a molded product using the same.SOLUTION: A long fiber-reinforced polyamide resin composition pellet is a long fiber-reinforced polyamide resin composition pellet containing a polyamide resin (A) and a reinforcement fiber (B), where the polyamide resin (A) contains a terminal-modified polyamide resin (a), the terminal-modified polyamide resin (a) is a resin having a structure composed of a structural unit different from a repeating structure unit constituting a main chain of a polymer in a terminal group of the polymer, the pellet contains 5-150 pts.mass of the reinforcement fiber (B) with respect to 100 pts.mass of the polyamide resin (A), a length of the reinforcement fiber (B) is substantially the same as a length of the pellet, and the reinforcement fiber (B) is arrayed in a long direction of the pellet.SELECTED DRAWING: None

Description

  The present invention relates to a long fiber reinforced polyamide resin composition pellet containing a terminal-modified polyamide resin, which is excellent in fluidity and mechanical properties during molding, and a molded article comprising the same.

  Polyamide resins have excellent mechanical and thermal properties, and are therefore widely used as materials for various molded products such as fibers, various containers, films, electrical / electronic equipment parts, automotive parts and mechanical parts. .

  In recent years, there has been an increasing demand for miniaturization, complexity, thinning, and weight reduction of molded products, and polyamide resins are required to have further improved mechanical properties and moldability. As a means for improving mechanical properties, it is known to add a fibrous reinforcing material such as glass fiber or carbon fiber to polyamide resin, and in order to fully draw out the performance of the fibrous reinforcing material. It is necessary to keep the fiber length long.

  In general, in order to keep the fiber length of the fibrous reinforcement long, long fiber reinforced polyamide resin pellets whose reinforcing fiber length is the same as the pellet length are known. For example, molten polyamide resin is reinforced fiber roving A long fiber reinforced polyamide resin composition obtained by heating the long fiber reinforced resin pellets impregnated into the polyamide resin at a temperature not higher than the melting point of the polyamide resin and increasing the molecular weight of the polyamide resin by solid phase polymerization (see, for example, Patent Document 1), A composite comprising a continuous reinforcing fiber bundle and a thermoplastic polymer having a weight average molecular weight of 200 to 50,000 and a low melt viscosity is disposed so that a thermoplastic resin having a weight average molecular weight of 10,000 or more is in contact with the composite. The molding material which becomes (for example, refer patent document 2) is proposed.

JP 2011-241296 A (Claims) JP-A-10-138379 (Claims)

  However, when the molecular weight of the polyamide resin is increased, the viscosity of the resin increases and the fluidity at the time of molding processing is impaired. Further, the reinforcing fibers are easily broken by the shearing force at the time of molding, so that the mechanical characteristics are also lowered. In the techniques disclosed in Patent Documents 1 and 2, although the mechanical properties are improved because the length of the reinforcing fiber in the molded article is kept long, the mechanical properties are increased because the molecular weight of the polyamide resin is increased. It was difficult to achieve both the fluidity during molding and molding.

  Accordingly, an object of the present invention is to provide a long fiber reinforced polyamide resin composition pellet excellent in fluidity and mechanical properties during molding and a molded article using the same.

  As a result of repeated studies to achieve both flowability during molding and mechanical properties, the present inventors have end-modified having a specific structure at the end of the polyamide resin of the long-fiber-reinforced polyamide resin composition pellets. It has been found that the above-mentioned problems can be solved by using a polyamide resin composition containing a polyamide resin, and the present invention has been achieved.

The present invention is to solve the above-mentioned problems, and the long fiber reinforced polyamide resin composition pellets of the present invention mainly have the following configuration.
[1] A long fiber reinforced polyamide resin composition pellet containing a polyamide resin (A) and a reinforcing fiber (B),
The polyamide resin (A) contains a terminal-modified polyamide resin (a),
The terminal-modified polyamide resin (a) is a resin having a structure composed of a structural unit different from the repeating structural unit constituting the main chain of the polymer in the terminal group of the polymer,
For 100 parts by mass of the polyamide resin (A),
Including 5-150 parts by mass of reinforcing fiber (B),
The length of the reinforcing fiber (B) is substantially the same as the length of the pellet;
And the reinforcing fibers (B) are arranged in the longitudinal direction of the pellets,
Long fiber reinforced polyamide resin composition pellets.
[2] The terminal-modified polyamide resin (a) contains a polyamide resin having a terminal structure represented by the following general formula (I):
The long fiber reinforced polyamide resin composition pellet according to [1], wherein the content of the terminal structure represented by the following general formula (I) with respect to the polyamide resin (A) is 1% by mass or more and 20% by mass or less.
_{^{-X- (R 1 -O) m -R}} 2 (I)
(In the above general formula (I), m represents a range of 2 to 100. R ¹ is a divalent hydrocarbon group having 2 to 10 carbon atoms, and R ² is a monovalent hydrocarbon having 1 to 30 carbon atoms. represents groups respectively.-X- is _{-NH -, - N (CH 3} ) - or - (C = O) -. represents the m ^{R 1} contained in the general formula (I) and are either the same or different May be.)
[3] The terminal-modified polyamide resin (a) further contains a polyamide resin having a terminal structure represented by the following general formula (II):
The long fiber reinforced polyamide resin composition pellet according to [2], wherein the content of the terminal structure represented by the following general formula (II) with respect to the polyamide resin (A) is 0.1% by mass or more and 5% by mass or less. .
-YR ³ (II)
(In the general formula (II), R ³ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. In the general formula (I), —X— is —NH— or —N (CH ₃ ) —. In this case, -Y- in the general formula (II) represents-(C = O)-, and when -X- in the general formula (I) is-(C = O)-, the general formula (II) —Y— in — represents —NH— or —N (CH ₃ ) —.
[4] The long fiber-reinforced polyamide resin composition pellet according to any one of [1] to [3], wherein the reinforcing fiber (B) is a glass fiber or a carbon fiber.
[5] The terminal-modified polyamide resin (a) has a terminal structure represented by the general formula (I) and a terminal structure represented by the general formula (II). Containing
The total of the content of the terminal structure represented by the general formula (I) and the content of the terminal structure represented by the general formula (II) contained in the polyamide resin (A) 1t is 60 [mol / t] or more and 250 [mol / t] or less,
And the ratio ((I) / () of the content [mol / t] of the terminal structure represented by the general formula (I) and the content [mol / t] of the terminal structure represented by the general formula (II). II)) is a long fiber reinforced polyamide resin composition pellet according to any one of [3] to [4], which is 0.3 to 2.5.
[6] The polyamide resin (A) contains a polyamide resin having an amino terminal group and a polyamide resin having a carboxyl terminal group,
The total of amino end group content and carboxyl end group content contained in the polyamide resin (A) 1t is 50 [mol / t] or more and 150 [mol / t] or less,
And the ratio (amino terminal group / carboxyl terminal group) of the amino terminal group content [mol / t] and the carboxyl terminal group content [mol / t] is 0.5 to 2.5 [1] to [ 5] The long fiber reinforced polyamide resin composition pellets according to any one of [5].
[7] The relative viscosity (ηr) of the polyamide resin (A) at a temperature of 25 ° C. in a 98% sulfuric acid solution having a resin concentration of 0.01 g / ml is 1.3 to 3.0 [1] to [6] The long fiber reinforced polyamide resin composition pellet according to any one of the above.
[8] The long fiber reinforced polyamide resin according to any one of [1] to [7], wherein the weight average molecular weight Mw of the polyamide resin (A) measured by gel permeation chromatography is 15,000 to 50,000. Composition pellets.
[9] The long fiber reinforced polyamide resin according to any one of [1] to [8], wherein the polyamide resin (A) has a melting point of + 60 ° C. and a shear rate of 9728 sec ⁻¹ , and the melt viscosity is 30 Pa · s or less. Composition pellets.
[10] The content retention rate of the structure represented by the general formula (I) ((content after residence / content before residence) × 100) before and after residence for 60 minutes under a temperature of melting point + 60 ° C. The long fiber reinforced polyamide resin composition pellet according to any one of [2] to [9], which is 80% or more.
[11] Weight average molecular weight retention ((weight average molecular weight after residence / weight average molecular weight before residence) × 100) of the polyamide resin (A) before and after residence for 60 minutes under the condition of melting point + 60 ° C. is 80% to The long fiber reinforced polyamide resin composition pellet according to any one of [1] to [10], which is 120%.
[12] The melt viscosity retention ((melt viscosity after residence / melt viscosity before residence) × 100) of the polyamide resin (A) before and after residence for 60 minutes under the condition of melting point + 60 ° C. is 80% to 120%. The long fiber reinforced polyamide resin composition pellets according to any one of [1] to [11].
[13] The mass reduction rate of the polyamide resin (A) before and after residence for 40 minutes under a condition of a melting point + 60 ° C. in a nitrogen atmosphere is 4% or less, and any one of [1] to [12] Long fiber reinforced polyamide resin composition pellets.
[14] 0.1 to 65 parts by mass of a thermoplastic polymer (C) having a melt viscosity of 0.01 to 20 Pa · s at 200 ° C. with respect to 100 parts by mass of the polyamide resin (A) The long fiber reinforced polyamide resin composition pellet according to any one of [1] to [13], wherein the polymer (C) is attached to the reinforcing fiber (B).
[15] A molded product comprising the long fiber reinforced polyamide resin composition pellets according to any one of [1] to [14], wherein the weight average fiber length of the reinforced fibers in the molded product is 0.3 mm or greater and 5.0 mm or less. .

  According to the present invention, by using a specific terminal-modified polyamide resin in the long fiber reinforced polyamide resin composition pellets, the long fiber reinforced polyamide resin composition pellets excellent in fluidity and mechanical properties during molding and the same A molded product using can be obtained.

  Therefore, the molded product using the long fiber reinforced polyamide resin composition pellets of the present invention can be molded into complex shapes in addition to mechanical properties such as automobile parts, electrical / electronic parts, building parts and sports equipment parts. Can be suitably used for various applications that require

Schematic which shows the one aspect | mode of the cross-sectional shape of the long fiber reinforced polyamide resin composition pellet of embodiment of this invention. Schematic which shows another one aspect | mode of the cross-sectional shape of the long fiber reinforced polyamide resin composition pellet of embodiment of this invention.

  Next, the long fiber reinforced polyamide resin composition pellets and molded articles thereof according to the present invention will be specifically described. The long fiber reinforced polyamide resin composition pellet of the present invention is a long fiber reinforced polyamide resin composition pellet containing a polyamide resin (A) and a reinforcing fiber (B), wherein the polyamide resin (A) is a terminal-modified polyamide resin ( a) containing the terminal-modified polyamide resin (a) having a structure composed of structural units different from the repeating structural units constituting the main chain of the polymer in the terminal group of the polymer, It is a long fiber reinforced polyamide resin composition pellet in which the length of B) is substantially the same as the length of the pellet, and the reinforcing fibers (B) are arranged in the longitudinal direction of the pellet.

  The polyamide resin used in the embodiment of the present invention is a polyamide resin that can be obtained as a main raw material from at least one selected from the group consisting of a combination consisting of a diamine and a dicarboxylic acid, an amino acid, and a lactam.

  As a chemical structure which comprises the main structural unit of a polyamide resin, when using an amino acid or a lactam as a raw material, a C4-C20 thing is preferable. Moreover, when using diamine and dicarboxylic acid as a raw material, it is preferable that carbon number of diamine is the range of 2-20, and it is preferable that the carbon number of dicarboxylic acid is the range of 2-20. The following are mentioned as a typical example of a raw material.

  Specifically, amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid. Lactams such as ε-caprolactam, ω-undecanactam, and ω-laurolactam. Ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecane Aliphatic diamines such as diamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,5-diaminopentane, 2-methyl-1,8-diaminooctane; cyclohexanediamine, bis- ( Cycloaliphatic diamines such as 4-aminocyclohexyl) methane and bis (3-methyl-4-aminocyclohexyl) methane; Diamine such as family diamine. Aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid; terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, Aromatic dicarboxylic acids such as 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; Examples thereof include dialkyl esters and dichlorides.

  In the embodiment of the present invention, a polyamide homopolymer or copolymer derived from these raw materials can be used as the polyamide resin (A). It is allowed that two or more of these polyamide resins and terminal-modified polyamide resins (a), which will be described later in detail, are mixed to form a polyamide resin (A).

  The terminal-modified polyamide resin (a) used in the embodiment of the present invention is a resin having a structure composed of a structural unit different from the repeating structural unit constituting the main chain of the polymer of the polyamide resin at the terminal of the polymer. is there. That is, it is a polyamide resin having a modified structure at the end of the polymer. In the present invention, it is allowed that two or more kinds of terminal-modified polyamide resins having different structures are mixed to form a terminal-modified polyamide resin (a).

  In the embodiment of the present invention, from the viewpoint of further improving the mechanical properties and the thermal stability during melt residence, the structural unit derived from the raw materials exemplified above is composed of a polyamide resin excluding the modified structure. It is preferable to have 80 mol% or more, more preferably 90 mol% or more, and even more preferably 100 mol% in 100 mol% of all structural units. Moreover, it is preferable that the polymerization structure derived from the raw material illustrated above is linear.

  The melting point (Tm) of the terminal-modified polyamide resin (a) used in the embodiment of the present invention is preferably 200 ° C. or higher. Here, the melting point of the terminal-modified polyamide resin can be determined by differential scanning calorimetry (DSC). The measurement method is as follows. Weigh 5-7 mg of terminal-modified polyamide resin. In a nitrogen atmosphere, the temperature is raised from a temperature of 20 ° C. to Tm + 30 ° C. at a heating rate of 20 ° C./min. Subsequently, the temperature is lowered to a temperature of 20 ° C. at a temperature lowering rate of 20 ° C./min. Again, the temperature at the apex of the endothermic peak that appears when the temperature is raised from the temperature of 20 ° C. to Tm + 30 ° C. at a heating rate of 20 ° C./min is defined as the melting point (Tm).

  Examples of the terminal-modified polyamide resin having a melting point of 200 ° C. or higher include polyamide resins having a modified structure at the ends of the following polyamides and copolymers thereof. Two or more of these may be used depending on the required properties such as heat resistance, toughness and surface properties.

  Polyamides include polycaproamide (polyamide 6), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), polyhexamethylene adipamide (polyamide 66), polytetramethylene adipamide (polyamide 46), Polypentamethylene adipamide (polyamide 56), polytetramethylene sebacamide (polyamide 410), polypentamethylene sebacamide (polyamide 510), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide ( Polyamide 612), polydecamethylene sebacamide (nylon 1010), polydecamethylene dodecamide (nylon 1012), polymetaxylylene adipamide (MXD6), polymetaxylylene sebacamide (MXD10), polypara Silylene sebacamide (PXD10), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (polyamide 10T), polyundecamethylene terephthalamide (polyamide 11T), polydodecamethylene terephthalamide (polyamide 12T), poly Pentamethylene terephthalamide / polyhexamethylene terephthalamide copolymer (polyamide 5T / 6T), poly-2-methylpentamethylene terephthalamide / polyhexamethylene terephthalamide (polyamide M5T / 6T), polyhexamethylene adipamide / polyhexamethylene Terephthalamide copolymer (polyamide 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I) , Polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide (polyamide 66 / 6T / 6I), polybis (3-methyl-4-aminocyclohexyl) methane terephthalamide (polyamide MACMT), polybis (3 -Methyl-4-aminocyclohexyl) methane isophthalamide (polyamide MACMI), polybis (3-methyl-4-aminocyclohexyl) methane dodecamide (polyamide MACM12), polybis (4-aminocyclohexyl) methane terephthalamide (polyamide PACMT), Polybis (4-aminocyclohexyl) methane isophthalamide (polyamide PACMI), and polybis (4-aminocyclohexyl) methane dodecamide (polyamide PACM1) 2).

  Particularly preferred polyamides have structures modified at the ends such as polyamide 6, polyamide 66, polyamide 56, polyamide 410, polyamide 510, polyamide 610, polyamide 6/66, polyamide 6/12, polyamide 9T, and polyamide 10T. Mention may be made of polyamide.

  The terminal-modified polyamide resin (a) used in the embodiment of the present invention has a structure modified at its terminal. The modified structure is different from the repeating structure constituting the main chain of the polymer.

  Examples of the modified structure include structures derived from saturated aliphatic compounds, unsaturated aliphatic compounds, and aromatic compounds. Two or more of these may be used. From the viewpoint of further reducing the melt viscosity (that is, improving the fluidity at the time of melting), a structure derived from a saturated aliphatic compound or an aromatic compound is more preferable, and a structure derived from a saturated aliphatic compound is more preferable. Used.

  In the embodiment of the present invention, examples of the “modified structure” (terminal structure) include a residue of a compound for terminal modification described later.

In the embodiment of the present invention, the terminal-modified polyamide resin (a) preferably contains a polyamide resin having a terminal structure represented by the following general formula (I). Since the terminal structure represented by the following general formula (I) has an alkylene oxide structure, the resulting polymer has high molecular mobility and excellent affinity with an amide group. Moreover, the structure represented by the following general formula (I) at the terminal of the polyamide resin is interposed between the polyamide molecular chains, whereby the free volume of the polymer is further increased and the entanglement is further decreased. As a result, the molecular mobility of the polymer is further increased, and the melt viscosity can be reduced. At the same time, the dispersibility of the reinforcing fibers can be greatly improved by the affinity with the reinforcing fibers due to the alkylene oxide structure. Such an effect is an extremely high effect compared with the case where the polyalkylene oxide structure is mainly included in the main chain of the polyamide resin.
_{^{-X- (R 1 -O) m -R}} 2 (I)

  In said general formula (I), m represents the range of 2-100. As m is larger, the effect of reducing the melt viscosity is effectively exhibited. m is preferably 5 or more, more preferably 8 or more, and still more preferably 16 or more. On the other hand, the smaller m is, the higher the heat resistance can be maintained. m is preferably 70 or less, and more preferably 50 or less. From the viewpoint of maintaining the characteristics derived from the main structural unit of the polyamide resin, in the present invention, the terminal-modified polyamide resin preferably has the structure represented by the above general formula (I) only at the end of the polymer.

In the general formula (I), R ¹ represents a divalent hydrocarbon group having 2 to 10 carbon atoms. From the viewpoint of the affinity with the main structural unit of the polyamide resin, a hydrocarbon group having 2 to 6 carbon atoms is more preferable, and a hydrocarbon group having 2 to 4 carbon atoms is a more preferable embodiment. From the viewpoint of thermal stability of the terminal-modified polyamide resin and prevention of coloring, it is a more preferable embodiment that R ¹ is a saturated hydrocarbon group.

Examples of R ¹ include an ethylene group, 1,3-trimethylene group, isopropylene group, 1,4-tetramethylene group, 1,5-pentamethylene group, 1,6-hexamethylene group, and the like. Each R ¹ can be a combination of hydrocarbon groups having different carbon numbers. R ¹ is preferably composed of at least a divalent saturated hydrocarbon group having 2 carbon atoms and a divalent saturated hydrocarbon group having 3 carbon atoms. More preferably, the polyamide resin is composed of an ethylene group excellent in affinity with the main structural unit of the polyamide resin and an isopropylene group having a large free volume, and the effect of reducing the melt viscosity can be expressed more effectively. In this case, it is preferable that the terminal structure represented by the general formula (I) contains 10 or more ethylene groups and 6 or less isopropylene groups. It can introduce | transduce and can improve a melt viscosity reduction effect more.

R ² represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. Since the smaller the carbon number of R ² is, the better the affinity with the main structural unit of the polyamide resin is, so a hydrocarbon group having 1 to 20 carbon atoms is preferable, and a hydrocarbon group having 1 to 10 carbon atoms is more preferably used. Further, from the viewpoint of thermal stability of the terminal-modified polyamide resin and prevention of coloring, it is a more preferable embodiment that R ² is a monovalent saturated hydrocarbon group. Examples of R ² include methyl, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Among them, the main structural unit of polyamide resin A methyl group and an ethyl group which are excellent in affinity are more preferable.

In the above general formula (I), —X— represents —NH—, —N (CH ₃ ) — or — (C═O) —. Among these, —NH— which is excellent in affinity with the main structural unit of the polyamide resin is more preferable.

  The terminal-modified polyamide resin (a) used in the embodiment of the present invention preferably has a terminal structure represented by the general formula (I) at at least one terminal of the polymer constituting the terminal-modified polyamide resin.

  In the embodiment of the present invention, the polyamide resin (A) preferably has a content of the terminal structure represented by the general formula (I) of 1% by mass or more and 20% by mass or less.

  That is, in the present invention, the polyamide resin (A) contains a polyamide resin having a terminal structure represented by the general formula (I) as a terminal-modified polyamide resin (a), and the polyamide resin (A) On the other hand, it is preferable that the content rate of the terminal structure represented by general formula (I) is 1 mass% or more and 20 mass% or less.

  When the content of the terminal structure represented by the general formula (I) is 1% by mass or more, the melt viscosity of the terminal-modified polyamide resin can be further reduced, the fluidity during molding is improved, and the reinforcing fiber is Breaking can be suppressed and the dispersibility of the reinforcing fibers can be improved, whereby the mechanical properties can be improved. The content of the terminal structure represented by the general formula (I) is more preferably 3% by mass or more, and further preferably 5% by mass or more.

  On the other hand, when the content of the terminal structure represented by the general formula (I) is 20% by mass or less, discoloration due to oxidative degradation of the alkylene oxide structure in the structure represented by the general formula (I) at the time of melt residence Suppresses the increase in gas components due to thermal decomposition, further improves the thermal stability during melt residence, improves the fluidity of the molded product, and lowers the mechanical properties of the molded product due to the generated gas Can be further reduced. Moreover, since the molecular weight of the terminal-modified polyamide resin can be further increased, the mechanical characteristics can be further improved. The content of the terminal structure represented by the general formula (I) is more preferably 15% by mass or less, and further preferably 10% by mass or less.

  The content of the terminal structure represented by the general formula (I) in the terminal-modified polyamide resin used in the embodiment of the present invention is, for example, a general formula (III) described later, which is used when the terminal-modified polyamide resin is produced. It is possible to adjust to the desired range by adjusting the blending amount of the compound for terminal modification represented by ().

  In the embodiment of the present invention, it is preferable that the terminal-modified polyamide resin (a) further contains a polyamide resin having a terminal structure represented by the general formula (II). As described above, by including the polyamide resin having the terminal structure represented by the general formula (I), the melt viscosity of the terminal-modified polyamide resin is reduced, and the fluidity at the time of molding and the mechanical breakage of the reinforcing fiber are suppressed. Although the strength can be improved, the thermal decomposition of the terminal structure represented by the general formula (I) tends to proceed at the time of melt residence for a long time such as molding. In particular, a polyamide resin whose terminal structure is not modified has an amino terminal group or a carboxyl terminal group, and these amino terminal group and carboxyl group act as a thermal decomposition catalyst for the terminal structure represented by the general formula (I). . Therefore, by reducing the amount of amino terminal groups and carboxyl terminal groups in the polyamide resin, thermal decomposition of the terminal structure represented by the general formula (I) is suppressed, and the terminal structure represented by the general formula (I) It is possible to further improve the thermal stability at the time of melting residence while maintaining the effect of reducing the melt viscosity.

  For example, in the present invention, the terminal end-modifying compound represented by the general formula (III) to be described later is reacted with the carboxyl terminal group of the polyamide resin in which both terminal structures are not modified, thereby allowing the general formula (I) to react. A polyamide resin having a terminal structure represented by can be obtained. However, the terminal-modified polyamide resin thus obtained has one terminal modified with the structure represented by the general formula (I), but the other terminal is not modified and remains the amino terminal or carboxyl terminal. It is. Thus, for example, such a polyamide resin (that is, a polyamide resin in which only one terminal is modified with a structure represented by the general formula (I)), a compound for terminal modification represented by the general formula (IV) to be described later By further reacting, the other terminal can be modified to obtain a polyamide resin further having a terminal structure represented by the following general formula (II).

Compared with the case where only the terminal structure represented by the general formula (I) is introduced into the polyamide resin, by introducing the terminal structure represented by the following general formula (II) further, it is represented by the general formula (I). The thermal decomposition of the structure can be suppressed. And thereby, it is possible to further improve the thermal stability during the melt residence by the terminal structure represented by the general formula (I), it is possible to maintain the effect of reducing the melt viscosity, the flowability during molding and Mechanical properties can be improved.
-YR ³ (II)

In the general formula (II), R ³ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. Since the smaller the carbon number of R ^3, the better the affinity with the main structural unit of the polyamide resin, it is preferably a hydrocarbon group having 1 to 30 carbon atoms. Specifically, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, Straight chain such as heptadecyl group, octadecyl group, nonadecyl group, icosyl group, eicosyl group, heneicosyl group, heneicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triacontyl Branched alkyl groups such as alkyl groups, isopropyl groups, isobutyl groups, tert-butyl groups, isopentyl groups, neopentyl groups, etc., cycloalkyl groups such as cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, and aryl groups such as phenyl groups, tolyl groups, etc. Benzyl group, and aralkyl groups such as 2-phenylethyl groups. From the viewpoint of thermal stability of the terminal-modified polyamide resin and prevention of coloring, R ³ is more preferably a monovalent saturated hydrocarbon group having 1 to 20 carbon atoms or an aryl group.

When X in the general formula (I) is —NH— or —N (CH ₃ ) —, —Y— in the above general formula (II) represents — (C═O) — When X in Formula (I) is — (C═O) —, Y in General Formula (II) above represents —NH— or —N (CH ₃ ) —.

  Usually, in the terminal group of the polyamide resin in which both ends are not modified, one terminal group is an amino terminal group and the other terminal group is a carboxyl terminal group.

  As will be described in detail later, the terminal structure represented by the general formula (I) is obtained by reacting a terminal-modified compound represented by the following general formula (III) with a polyamide resin whose terminal is not modified. A polyamide resin can be obtained.

Here, when the compound for terminal modification represented by the general formula (III) has an amino terminal group, the compound for terminal modification reacts with the carboxyl terminal group of the polyamide resin, and X in the general formula (I) is -NH. - or -N (CH ₃₎ - and it becomes. In this case, the amino terminal group which is the other terminal of the polyamide resin is reacted with a compound for terminal modification represented by the general formula (IV) described later, so that the above-mentioned general formula is added to the other terminal of the polyamide resin. The terminal structure of (II) can be introduced. In this case, Y in the general formula (II) is-(C = O)-.

On the other hand, when the compound for terminal modification represented by the general formula (III) has a carboxyl terminal group, the compound for terminal modification reacts with the amino terminal group of the polyamide resin, and X in the general formula (I) is-(C = O)-. In this case, the other end of the polyamide resin is reacted with a terminal-modifying compound represented by the following general formula (IV) to react the other end of the polyamide resin with the above general formula. The terminal structure of (II) can be introduced. In this case, Y in the general formula (II) is —NH— or —N (CH ₃ ) —.

  In this invention, it is preferable that the content rate of the terminal structure represented by general formula (II) is 0.1 to 5 mass% with respect to a polyamide resin (A). That is, in the present invention, the polyamide resin (A) contains a polyamide resin having a terminal structure represented by the general formula (II) as a terminal-modified polyamide resin (a), and the polyamide resin (A) On the other hand, it is preferable that the content rate of the terminal structure represented by general formula (II) is 0.1 mass% or more and 5 mass% or less.

  When the content of the terminal structure represented by the general formula (II) is 0.1% by mass or more, thermal decomposition of the structure represented by the general formula (I) in the terminal-modified polyamide resin is suppressed during the residence time. , Which can further improve the thermal stability during melt residence, suppress the increase of gas components due to thermal decomposition of the alkylene oxide structure in the terminal structure represented by the general formula (I), and molding caused by the generated gas The deterioration of the mechanical properties of the product can be further reduced. The content of the terminal structure represented by the general formula (II) is more preferably 0.2% by mass or more, and further preferably 0.4% by mass or more.

  On the other hand, when the content of the terminal structure represented by the general formula (II) is 5% by mass or less, the mechanical properties and the thermal stability during melt residence can be further improved. The content of the terminal structure represented by the general formula (II) is more preferably 3% by mass or less, and further preferably 1% by mass or less.

  In the present invention, the content of the terminal structure represented by the general formula (II) in the terminal-modified polyamide resin is, for example, the terminal represented by the general formula (IV) described later used when producing the terminal-modified polyamide resin. By adjusting the compounding amount of the modifying compound, it can be adjusted to a desired range.

  To summarize the above, in the present invention, the polyamide resin (A) preferably contains a terminal-modified polyamide resin (a). The polyamide resin (A) may contain two or more polyamide resins as described above. Further, the polyamide resin (A) may include a polyamide resin other than the terminal-modified polyamide resin (a) (for example, a polyamide resin in which both terminals are not modified).

  In the present invention, the terminal-modified polyamide resin (a) preferably contains a polyamide resin having a terminal structure represented by the general formula (I). In the present invention, the terminal-modified polyamide resin (a) may contain two or more kinds of terminal-modified polyamide resins as described above.

  In the present invention, the terminal-modified polyamide resin (a) contains a polyamide resin having a terminal structure represented by the general formula (I) and a polyamide resin having a terminal structure represented by the general formula (II). It is preferable.

In the present invention,
[Aspect i] A terminal-modified polyamide resin (a) is a polyamide resin having only a terminal structure represented by general formula (I) (for example, one terminal is modified with a terminal structure represented by general formula (I). A polyamide resin whose other end is not modified) and a polyamide resin having only a terminal structure represented by the general formula (II) (for example, one end is represented by the general formula (II)) It may be an embodiment containing a polyamide resin which is modified with a terminal structure, but the other terminal is not modified,
[Aspect ii] The terminal-modified polyamide resin (a) is a polyamide resin having a terminal structure represented by the general formula (I) and a terminal structure represented by the general formula (II) (that is, one terminal is represented by the general formula ( It may be an embodiment containing a polyamide resin which is modified with a terminal structure represented by I) and the other terminal is modified with a terminal structure represented by the general formula (II).
Of course, [aspect iii] the terminal-modified polyamide resin (a) contains a polyamide resin having a terminal structure represented by the general formula (I) and a terminal structure represented by the general formula (II). It may be an embodiment containing a polyamide resin having only the terminal structure represented by (I) and / or a polyamide resin having only the terminal structure represented by the general formula (II).

  A polyamide resin having a terminal structure represented by the general formula (I) and a terminal structure represented by the general formula (II) (in one polymer chain, one terminal is represented by the general formula (I). The polymer having a structure and a terminal structure represented by the general formula (II) at the other end) is also referred to as “terminal-modified polyamide resin having a terminal structure represented by the general formula (I)” in the present invention. It corresponds and also corresponds to “terminal-modified polyamide resin having a terminal structure represented by the general formula (II)”.

  Moreover, in this invention, it is preferable that the content rate of the terminal structure represented by general formula (I) is 1 mass% or more and 20 mass% or less with respect to a polyamide resin (A). In addition, it is preferable that the content of the terminal structure represented by the general formula (II) is 0.1% by mass or more and 5% by mass or less with respect to the polyamide resin (A).

  In the present invention, the terminal-modified polyamide resin (a) has a terminal-modified polyamide resin having a terminal structure represented by the general formula (I) and a terminal structure having a terminal structure represented by the general formula (II). The content [mol / t] of the terminal structure represented by the general formula (I) and the terminal represented by the general formula (II), which contains the modified polyamide resin and is contained in the polyamide resin (A) 1t. It is preferable that the total content [mol / t] of the structure is 60 [mol / t] or more and 250 [mol / t] or less. By adding 60 mol or more in total of the terminal structure represented by the general formula (I) and the terminal structure represented by the general formula (II) in the terminal modified polyamide resin 1t, the melt viscosity of the terminal modified polyamide resin is increased. It is possible to further reduce and improve the fluidity during the molding process, and it is possible to improve mechanical properties by suppressing breakage of the reinforcing fibers and improving dispersibility of the reinforcing fibers. The total content of these terminal structures is more preferably 70 mol / t or more, and still more preferably 80 mol / t or more.

  On the other hand, the polyamide resin (A) 1t contains a terminal structure represented by the general formula (I) and a terminal structure represented by the general formula (II) in a total amount of 250 mol / t or less, so The thermal stability of the fiber can be further improved, and the mechanical properties can be improved by suppressing breakage of the reinforcing fiber and improving the dispersibility of the reinforcing fiber. The total content of these terminal structures is more preferably 225 mol / t, still more preferably 200 mol / t or less.

  In the present invention, the total amount of the terminal structure represented by the general formula (I) and the terminal structure represented by the general formula (II) in the terminal modified polyamide resin (A) is, for example, when producing the terminal modified polyamide resin. It can adjust to the desired range by adjusting the compounding quantity of the compound for terminal modification | reformation represented by general formula (III) mentioned later used for and the terminal modification compound represented by general formula (IV).

  Further, the ratio of the content [mol / t] of the terminal structure represented by the general formula (I) to the content [mol / t] of the terminal structure represented by the general formula (II) ((I) / ( II)) is preferably 0.3 or more and 2.5 or less. The polyamide resin undergoes a molecular weight increase due to a polymerization reaction between an amino terminal group and a carboxyl terminal group simultaneously with a decrease in the molecular weight due to thermal decomposition during melt residence. This shows that as the molar ratio ((I) / (II)) is further away from 1, the difference between the amount of amino end groups to be modified (blocked) and the amount of carboxyl end groups increases. As it is, the polymerization reaction during the melt residence is less likely to proceed, and the molecular weight decrease due to thermal decomposition becomes larger, so the melt viscosity and the molecular weight decrease during the melt residence tend to increase. Moreover, the larger the difference is, the more difficult the polymerization reaction proceeds during the melt residence, that is, the terminal group is not consumed by the polymerization reaction. As described above, the terminal group (amino terminal group or carboxyl terminal group) serves as a thermal decomposition catalyst for the terminal structure represented by the general formula (I), and the alkylene oxide in the terminal structure represented by the general formula (I). In order to promote thermal decomposition of the structure, the melt viscosity tends to increase as the difference increases.

  By setting the molar ratio ((I) / (II)) of the above content to 0.3 or more, the melt viscosity of the terminal-modified polyamide resin can be further reduced, and at the same time, the terminal-modified polyamide at the time of melt residence The thermal decomposition of the structure represented by the general formula (I) in the resin can be further suppressed, and the thermal stability can be further improved. And thereby, it is possible to further improve the thermal stability during melt residence by the terminal structure represented by the general formula (I), and to maintain the effect of reducing the melt viscosity. Can be improved. The molar ratio ((I) / (II)) of the above content is more preferably 0.5 or more, further preferably 0.6 or more, and most preferably 0.8 or more.

  On the other hand, by setting the molar ratio ((I) / (II)) of the above content to 2.5 or less, the terminal structure represented by the general formula (I) in the terminal-modified polyamide resin at the time of melt residence Thermal decomposition can be further suppressed. Thereby, since the melt viscosity reduction effect can be maintained, the mechanical properties of the molded product can be improved. The molar ratio ((I) / (II)) of the above content is more preferably 2.2 or less, and further preferably 2.0 or less.

Here, the content of the terminal structure represented by the general formula (I) and the terminal structure represented by the general formula (II) in the polyamide resin (A) can be determined by ¹ H-NMR measurement, respectively. . The measurement and calculation method is as follows.

First, a deuterated sulfuric acid solution having a polyamide resin (A) concentration of 50 mg / mL is prepared, and ¹ H-NMR measurement is performed with 256 integrations. Spectrum integral value of R ^1, spectrum integral value of R ^2, spectrum integral value of R ^3, and from the spectrum integral value of the repeating structural units of the polyamide resin skeleton (the repeating structural units constituting the main chain of the polymer), each end structure Of the terminal structure (I) to the content (mol / t) and the content (mol / t) of the terminal structure (II) (hereinafter referred to as “molar ratio”). Can be calculated).

  In the present invention, the molar ratio ((I) / (II)) in the polyamide resin (A) is, for example, a terminal represented by the general formula (III) described later used when producing a terminal-modified polyamide resin. By adjusting the compounding ratio of the modifying compound and the terminal modifying compound represented by the general formula (IV), it can be adjusted to a desired range.

  In the present invention, the polyamide resin (A) preferably contains a polyamide resin having an amino terminal group and a polyamide resin having a carboxyl terminal group.

  In the present invention, a polyamide resin having an amino terminal group and a carboxyl terminal group (in one polymer chain, a polymer having an amino terminal group at one terminal and a carboxyl terminal group at the other terminal) is “amino It corresponds to “polyamide resin having terminal groups” and also corresponds to “polyamide resin having carboxyl end groups”.

In the present invention,
[Aspect i] The polyamide resin (A) has a polyamide resin having an amino end group at one end (having neither an amino end group nor a carboxyl end group at the other end), and a carboxyl end group at one end Or a polyamide resin having no amino terminal group or carboxyl terminal group at the other end.
[Aspect ii] The aspect in which the polyamide resin (A) contains a polyamide resin having an amino terminal group at one terminal and a carboxyl terminal group at the other terminal may be used.
Of course, [Aspect iii] The polyamide resin (A) contains a polyamide resin having an amino end group at one end and a carboxyl end group at the other end, and further having an amino end group at one end. It may be an embodiment containing a polyamide resin and / or a polyamide resin having a carboxyl terminal group at one end.

  In the present invention, the total content of amino terminal groups and carboxyl terminal groups contained in the polyamide resin (A) 1t is preferably 50 mol / t or more and 150 mol / t or less. By containing these terminal groups in a total of 50 mol or more in the polyamide resin 1t, it is possible to further suppress the decrease in the molecular weight retention during the melt residence and further improve the thermal stability. Thereby, breakage suppression of the reinforcing fibers and dispersibility of the reinforcing fibers can be further improved, and mechanical properties can be improved. The total content of these end groups is more preferably 60 mol / t or more, and still more preferably 80 mol / t or more.

  On the other hand, the structure represented by the general formula (I) in the terminal-modified polyamide resin at the time of melt residence by containing the amino terminal group and the carboxyl terminal group in the polyamide resin (A) 1t in a total of 150 mol / t or less. Thermal decomposition of the alkylene oxide structure therein can be suppressed. As a result, the molecular mobility of the polymer can be further increased and the melt viscosity can be reduced, the fluidity during molding can be improved, the breakage of the reinforcing fibers can be suppressed, and the dispersibility of the reinforcing fibers can be further improved. Characteristics can be improved. The total content of these end groups is more preferably 135 mol / t or less, and still more preferably 120 mol / t or less.

  Furthermore, in the present invention, the ratio of the amino terminal group content [mol / t] to the carboxyl terminal group content [mol / t] (amino terminal group / carboxyl terminal group) is 0.5 or more and 2.5. The following is preferable. As described above, the greater the difference between the amount of amino end groups and the amount of carboxyl end groups, the more difficult the polymerization during melt residence proceeds, and the lower the molecular weight due to thermal decomposition, the greater the decrease in melt viscosity and molecular weight during melt residence. Tend to be. Further, since the polymerization does not easily proceed during the melt residence, the terminal groups (amino terminal group and carboxyl terminal group) are not consumed in the polymerization reaction. As described above, these end groups serve as a thermal decomposition catalyst of the general formula (I) and promote thermal decomposition of the terminal structure represented by the general formula (I), so that the melt viscosity tends to increase.

  When the molar ratio of the above content (amino end group content / carboxyl end group content) is 0.5 or more, it is represented by the general formula (I) in the terminal-modified polyamide resin at the time of melt residence. The increase in melt viscosity can be suppressed because the thermal decomposition and molecular weight increase of the structure can be suppressed. The molar ratio of the above content (content of amino end group / content of carboxyl end group) is more preferably 0.6 or more, and still more preferably 0.8 or more.

  On the other hand, by setting the molar ratio of the above content (amino end group content / carboxyl end group content) to 2.5 or less, the general formula (I) in the terminal-modified polyamide resin at the time of melt residence is as follows. Since the thermal decomposition of the represented structure can be further suppressed, an increase in melt viscosity can be suppressed. The molar ratio of the above content (content of amino end group / content of carboxyl end group) is more preferably 2.4 or less, and even more preferably 2.3 or less.

  Here, the content of the amino terminal group in the polyamide resin (A) is determined by dissolving the polyamide resin in a phenol / ethanol mixed solution (ratio: 83.5 / 16.5 mass ratio) and using thymol blue as an indicator. It can be measured by titrating with an aqueous hydrochloric acid solution.

  The amount of carboxyl end groups in the polyamide resin (A) is measured by dissolving the polyamide resin in benzyl alcohol at 195 ° C., using phenolphthalein as an indicator, and titrating with an ethanol solution of potassium hydroxide. Can do.

  In the present invention, the ratio of the content of the amino terminal group and the content of the carboxyl terminal group of the polyamide resin (A) is represented by, for example, the general formula (III) described later used when producing the terminal-modified polyamide resin. By adjusting the compounding ratio of the compound for terminal modification and the compound for terminal modification represented by formula (IV) and the reaction time, it can be adjusted to a desired range.

  The polyamide resin (A) and the terminal-modified polyamide resin used in the present invention have a relative viscosity (ηr) at a temperature of 25 ° C. of a 98% sulfuric acid solution having a resin concentration of 0.01 g / ml of 1.3 to 3.0. It is preferable to be in the range. By setting ηr to 1.3 or more, toughness can be improved and the mechanical properties of the molded product can be improved. The relative viscosity (ηr) is more preferably 1.4 or more, and further preferably 1.5 or more. On the other hand, by setting ηr to 3.0 or less, it is possible to improve the moldability at the time of molding and to improve the mechanical characteristics by suppressing breakage of the reinforcing fibers. Preferably it is 2.5 or less, More preferably, it is 2.3 or less, More preferably, it is 2.1 or less.

  In the present invention, the relative viscosity of the terminal-modified polyamide resin is represented by, for example, a compound for terminal modification represented by the general formula (III) described later and the general formula (IV) used when the terminal-modified polyamide resin is produced. It can be adjusted to a desired range by adjusting the compounding amount of the compound for terminal modification and the reaction time.

  The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyamide resin (A) or terminal-modified polyamide resin used in the present invention is preferably 15,000 or more. By setting Mw to 15,000 or more, the mechanical characteristics can be further improved. The weight average molecular weight (Mw) is more preferably 18,000 or more, and further preferably 20,000 or more.

  Moreover, it is preferable that Mw is 50,000 or less. By setting Mw to 50,000 or less, it is possible to further reduce the melt viscosity, improve the moldability of the molded product using the polyamide resin composition, and improve the mechanical properties by suppressing breakage of the reinforcing fibers. . Mw is more preferably 45,000 or less, and further preferably 40,000 or less.

  In the present invention, the weight average molecular weight (Mw) is hexafluoroisopropanol (0.005N-sodium trifluoroacetate added) as a solvent, Shodex HFIP-806M (two) and HFIP-LG as a column, It is obtained by GPC measurement at 30 ° C. Polymethyl methacrylate is used as a molecular weight reference material.

  In the present invention, the weight average molecular weight of the polyamide resin (A) or the terminal-modified polyamide resin is, for example, a terminal-modifying compound represented by the general formula (III) described later and the general formula used when manufacturing the terminal-modified polyamide resin. It can be adjusted to a desired range by adjusting the blending amount of the compound for terminal modification represented by (IV) and the reaction time.

The polyamide resin (A) and the terminal-modified polyamide resin used in the present invention preferably have a melt viscosity of 30 Pa · s or less under the conditions of a melting point + 60 ° C. and a shear rate of 9728 sec ⁻¹ . By setting the melt viscosity under the conditions of melting point + 60 ° C. and shear rate 9728 sec ⁻¹ to 30 Pa · s or less, the moldability of the molded product using the polyamide resin composition is improved and the mechanical properties by suppressing breakage of the reinforcing fiber Can be improved. The melt viscosity is more preferably 20 Pa · s or less, further preferably 15 Pa · s or less, and further preferably 10 Pa · s or less.

This melt viscosity is the melting point of the polyamide resin (A) or the terminal-modified polyamide resin + 60 ° C., and is retained for 5 minutes in order to melt the terminal-modified polyamide resin, and then is subjected to a shear rate of 9728 sec ⁻¹ by a capillary flow meter. Can be measured. In the present invention, as an index for evaluating the melt viscosity, the melting point + 60 ° C. is selected as a temperature condition in which the effect of good fluidization of the melt is likely to appear and the thermal decomposition does not easily proceed in a short stay, and injection molding is performed. 9728 sec ⁻¹ was selected as the shear rate, which is a high shear condition assuming time.

  In the present invention, the melt viscosity of the polyamide resin (A) or the terminal-modified polyamide resin is, for example, a compound for terminal modification represented by the general formula (III) described later and a general formula ( It can be adjusted to a desired range by adjusting the blending amount of the compound for terminal modification represented by IV) and the reaction time.

  The terminal-modified polyamide resin used in the present invention has a content retention of the terminal structure represented by the general formula (I) ((content after residence / content before residence) before and after residence for 60 minutes under the condition of melting point + 60 ° C. ) × 100) is preferably 80% or more. By making the content retention of the terminal structure represented by the general formula (I) 80% or more, thermal decomposition of the terminal structure represented by the general formula (I) in the terminal-modified polyamide resin at the time of melt residence is achieved. It is possible to suppress the increase in melt viscosity. The content retention of the terminal structure represented by the general formula (I) is more preferably 85% or more, and further preferably 90% or more. Moreover, from the viewpoint of achieving both moldability and mechanical properties, the content retention of the terminal structure represented by the general formula (I) is preferably 100% or less.

This content retention rate is obtained for the polyamide resin (A) or the terminal-modified polyamide resin by determining the content of the terminal structure represented by the general formula (I) by the ¹ H-NMR measurement described above, and then in the capillary flow meter. Then, after having been retained for 60 minutes at the melting point of the terminal-modified polyamide resin at + 60 ° C., the content of the terminal structure represented by the general formula (I) is similarly determined, and represented by the general formula (I) before the melt retention It can be calculated by dividing by the content of the terminal structure and multiplying by 100. In the present invention, as an index for evaluating the melt viscosity, the melting point + 60 ° C. was selected as a temperature condition in which the effect of good fluidization of the melt is likely to appear and the thermal decomposition does not proceed easily in a short stay.

  In the present invention, the content retention rate of the terminal structure represented by the general formula (I) in the polyamide resin (A) or the terminal-modified polyamide resin is, for example, a general formula (described later) used when manufacturing the terminal-modified polyamide resin. It can be adjusted to a desired range by adjusting the compounding amount of the compound for terminal modification represented by III) and the compound for terminal modification represented by formula (IV) and the reaction time.

  In the present invention, the polyamide resin (A) and the terminal-modified polyamide resin have a weight average molecular weight retention ((weight average molecular weight after residence / weight average molecular weight before residence) × 100) before and after residence for 60 minutes under the condition of melting point + 60 ° C. 80 to 120% is preferable. By making this weight average molecular weight retention 80% or more, the mechanical properties can be further improved. The weight average molecular weight retention is more preferably 85% or more, and still more preferably 90% or more.

  On the other hand, by setting the weight molecular weight retention to 120% or less, the melt viscosity can be further reduced, so that the moldability of the molded product using the polyamide resin composition can be improved and the breakage of the reinforcing fibers can be suppressed. Mechanical properties can be improved. The weight average molecular weight retention is more preferably 115% or less, and even more preferably 110% or less.

  This weight molecular weight retention was measured for the polyamide resin (A) and the terminal-modified polyamide resin by the above-described gel permeation chromatography (GPC), and then in a capillary flow meter, the polyamide resin (A) The weight average molecular weight is measured in the same manner after being retained for 60 minutes at the melting point + 60 ° C. of the terminal-modified polyamide resin, and is calculated by dividing by the weight average molecular weight before melting and multiplying by 100. In the present invention, as an index for evaluating the melt viscosity, the melting point + 60 ° C. was selected as a temperature condition in which the effect of good fluidization of the melt is likely to appear and the thermal decomposition does not proceed easily in a short stay.

  In the present invention, the weight average molecular weight retention rate of the polyamide resin (A) or the terminal-modified polyamide resin is, for example, a compound for terminal modification represented by the general formula (III) described later used when the terminal-modified polyamide resin is produced. It is possible to adjust the blending amount of the compound for terminal modification represented by the general formula (IV) to a desired range depending on the reaction time.

  The polyamide resin (A) and the terminal-modified polyamide resin used in the present invention have a melt viscosity retention ratio ((melt viscosity after residence / melt viscosity before residence) × 100) before and after residence for 60 minutes under the condition of melting point + 60 ° C. It is preferable to be -120%. By setting the melt viscosity retention rate to 80% or more, the mechanical properties can be further improved. The melt viscosity retention is more preferably 85% or more, still more preferably 90% or more, and further preferably 95% or more. On the other hand, when the melt viscosity retention rate is 120% or less, the moldability of a molded product using the polyamide resin composition can be improved, and the mechanical properties can be improved by suppressing breakage of the reinforcing fibers. The melt viscosity retention is more preferably 115% or less, and even more preferably 110% or less.

This melt viscosity retention rate is the melting point of the polyamide resin (A) or the terminal-modified polyamide resin + 60 ° C., and the polyamide resin (A) or the terminal-modified polyamide resin is retained for 5 minutes to melt, and then the shear rate is 9728 sec ⁻¹ . Under the conditions, the polyamide resin (A) and the terminal-modified polyamide resin were retained for 60 minutes at the melt viscosity (melt viscosity before residence) measured by a capillary flow meter and the melting point of the terminal-modified polyamide resin + 60 ° C., and then the shear rate From the melt viscosity (melt viscosity before residence) measured by a capillary flow meter under the condition of 9728 sec ⁻¹ , it can be calculated by (melt viscosity after residence / melt viscosity before residence) × 100.

In the present invention, as an index for evaluating the melt viscosity retention rate, the melting point + 60 ° C. is selected as a temperature condition where the effect of good fluidization of the melt is likely to appear, and the thermal decomposition is difficult to proceed in a short stay, 9728 sec ⁻¹ was selected as the shear rate, which is a high shear condition assuming injection molding.

  In the present invention, the melt viscosity retention rate of the polyamide resin (A) or the terminal-modified polyamide resin is, for example, a compound for terminal modification represented by the following general formula (III) used in the production of the terminal-modified polyamide resin and the like. It can be adjusted to a desired range by adjusting the blending amount of the compound for terminal modification represented by the formula (IV) and the reaction time.

  In the present invention, it is preferable that the polyamide resin (A) and the terminal-modified polyamide resin have a mass reduction rate of 4% or less before and after residence for 40 minutes under a melting point + 60 ° C. in a nitrogen atmosphere. By setting the mass reduction rate to 4% or less, it is possible to further suppress deterioration in mechanical properties due to gas generated by thermal decomposition during processing. The mass reduction rate is more preferably 3% or less.

  This mass reduction rate can be measured using a thermogravimetric analyzer (TGA). In the present invention, as an index for evaluating the mass reduction rate, the melting point + 60 ° C. was selected as a temperature condition in which the effect of good fluidization of the melt is likely to appear and the thermal decomposition is difficult to proceed with a short stay.

  In the present invention, the mass reduction rate of the polyamide resin (A) or the terminal-modified polyamide resin is, for example, the terminal-modifying compound represented by the general formula (III) described later and the general formula used when producing the terminal-modified polyamide resin. It can be adjusted to a desired range by adjusting the blending amount of the compound for terminal modification represented by (IV) and the reaction time.

  Next, a method for producing a terminal-modified polyamide resin used in the embodiment of the present invention will be described.

As a production method of the terminal-modified polyamide resin used in the embodiment of the present invention, for example,
(1) A method of melting and kneading a polyamide resin, a compound for terminal modification, and if necessary, other components at a melting point or higher of the polyamide resin and reacting them, or mixing them in a solution and reacting them. And (2) a raw material constituting the main structural unit of the polyamide resin, a compound for terminal modification, and a method of adding and reacting other components as necessary (addition method during reaction).

  Specifically, it is preferable that the raw material of the terminal-modified polyamide resin is charged into a reaction vessel, purged with nitrogen, and reacted by heating. If the reaction time at this time is too short, not only the molecular weight does not increase, but also the oligomer component increases, so the mechanical properties may decrease. Therefore, it is preferable that the nitrogen flow time in the reaction time is 15 minutes or more. On the other hand, if the reaction time is too long, thermal decomposition proceeds and coloration or the like occurs. Therefore, the nitrogen flow time in the reaction time is preferably 8 hours or less.

  Examples of the terminal-modifying compound used in the embodiment of the present invention include saturated aliphatic compounds, unsaturated aliphatic compounds, and aromatic compounds. Two or more of these may be used. From the viewpoint of further improving fluidity, the terminal-modifying compound is preferably a saturated aliphatic compound or an aromatic compound, and more preferably a saturated aliphatic compound.

  Examples of saturated aliphatic compounds include monocyclic cycloalkane compounds such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, and cyclododecane, and bicyclic rings such as decahydronaphthalene. Cyclic saturated aliphatic compounds such as formula cycloalkane compounds, and carbon numbers such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, and heptadecane And chain saturated aliphatic compounds such as ˜15 hydrocarbon compounds. The cyclic saturated aliphatic compound may have a branched structure, and the chain saturated aliphatic compound may have a linear structure or a branched structure.

As the terminal modification compound used in the embodiment of the present invention, a saturated aliphatic compound having one or more terminal structures represented by the following general formula (V) is preferably used.
-(A-A) _r -W (V)
(In the general formula (V), A represents an alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 24 carbon atoms. A represents an atom other than a carbon atom and a hydrogen atom or a single bond. The number of repeating structural units represented by (a-A) represents 1 or more, and W is a hydroxyl group, an aldehyde group, a carboxyl group, a sulfo group, an amino group, a glycidyl group, an isocyanate group, a carbodiimide group, or an oxazoline group. Represents an oxazine group, an ester group, an amide group, a silanol group or a silyl ether group).

  In the embodiment of the present invention, from the viewpoint of further improving the melt fluidity, A in the general formula (V) is a residue obtained by removing two hydrogen atoms from a chain saturated aliphatic compound, and r is 1 It is preferable that W is a hydroxyl group. If r is 1 or more, the melt fluidity can be further improved. r is more preferably 3 or more, and still more preferably 5 or more. On the other hand, if r is less than 100, the mechanical properties can be further improved. r is more preferably 70 or less. From the viewpoint of further improving the melt fluidity and mechanical properties, a is preferably an oxygen atom or a single bond, and more preferably an oxygen atom.

  The terminal-modifying compound used in the embodiment of the present invention may have one terminal structure represented by the above general formula (V), or two or more terminal structures. From the viewpoint of further improving the mechanical properties, it is preferable to have 1 to 4 structures represented by the general formula (V), more preferably 1 to 3 structures.

  In the present invention, in order to obtain a terminal-modified polyamide resin having a terminal structure represented by the general formula (I), for example, when polymerizing amino acids, lactams and / or diamines and dicarboxylic acids, the above general formula By containing the compound for terminal modification represented by (V) in an amount of 1 to 20% by mass with respect to the total of amino acid, lactam, diamine and dicarboxylic acid, and bonding the compound for terminal modification to the terminal of the polyamide resin, A terminal-modified polyamide resin containing 1 to 20% by mass of the terminal structure represented by the general formula (I) can be obtained.

More preferably, the compound for terminal modification represented by the general formula (V) is a compound for terminal modification represented by the following general formula (III).
H—X— (R ¹ —O) _m —R ² (III)

In said general formula (III), m represents the range of 2-100. Like m in the general formula (I), m is preferably 5 or more, more preferably 8 or more, and further preferably 16 or more. On the other hand, m is preferably 70 or less, more preferably 50 or less. R ¹ represents a divalent hydrocarbon group having 2 to 10 carbon atoms, and R ² represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. Examples thereof include those exemplified as R ¹ and R ² in the general formula (I). X— represents —NH—, —N (CH ₃ ) — or —O (C═O) —. -NH-, which is excellent in reactivity with the terminal of the polyamide, is more preferable.

  Next, the terminal-modified polyamide resin used in the embodiment of the present invention has a terminal structure represented by the general formula (I) and a terminal structure represented by the general formula (II). An example of a method for obtaining the resin will be described.

For example, a method of reacting a raw material of a polyamide resin, a compound for terminal modification represented by the general formula (III) and a compound for terminal modification represented by the following general formula (IV) at the time of polymerization, polyamide resin and terminal modification And a method of melt-kneading the compound for use. Examples of the method of reacting at the time of polymerization include, for example, a method in which a polyamide resin raw material and a terminal modification compound are mixed in advance and then condensation is performed by heating, or a terminal modification compound is added during polymerization of the main component raw material. And the like.
HYR ³ (IV)

In the general formula (IV), R ³ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. Like the general formula (II), R ³ is a monovalent saturated hydrocarbon group from the viewpoint of thermal stability of the terminal-modified polyamide resin and prevention of coloring. When X in the general formula (III) is —NH— or —N (CH ₃ ) —, —Y— in the above general formula (IV) represents —O (C═O) — When X in the formula (III) is —O (C═O) —, Y in the above general formula (IV) represents —NH— or —N (CH ₃ ) —.

  The number average molecular weight of the compound for terminal modification represented by the general formula (III) is preferably 500 to 10,000. By setting the number average molecular weight to 500 or more, the melt viscosity can be further reduced and the impregnation property can be further improved. The number average molecular weight is more preferably 800 or more, and still more preferably 900 or more. On the other hand, by setting the number average molecular weight to 10,000 or less, the affinity with the main structural unit of the polyamide resin can be further improved, and the mechanical properties of the molded product can be further improved. The number average molecular weight is more preferably 5000 or less, still more preferably 2500 or less, and further preferably 1500 or less.

  Specific examples of the terminal modification compound represented by the general formula (III) include methoxypoly (ethylene glycol) amine, methoxypoly (trimethylene glycol) amine, methoxypoly (propylene glycol) amine, and methoxypoly (tetramethylene glycol) amine. , Methoxy poly (ethylene glycol) poly (propylene glycol) amine, methoxy poly (ethylene glycol) carboxylic acid, methoxy poly (trimethylene glycol) carboxylic acid, methoxy poly (propylene glycol) carboxylic acid, methoxy poly (tetramethylene glycol) carboxylic acid, and methoxy poly ( And ethylene glycol) poly (propylene glycol) carboxylic acid. When two types of polyalkylene glycols are included, a block polymerization structure may be taken, and a random copolymer structure is allowed. Two or more of the above-mentioned terminal modification compounds can be used.

  Specific examples of the terminal modification compound represented by the general formula (IV) include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, undecanoic acid, lauric acid. Alicyclic monocarboxylic acids such as tridecanoic acid, myristic acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, and serotic acid, cycloaliphatic carboxylic acid, and methylcyclohexanecarboxylic acid. Aromatic monocarboxylic acids such as carboxylic acid, benzoic acid, toluic acid, ethyl benzoic acid, phenylacetic acid, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, Nonylamine, decylamine, c Alicyclic monoamines such as decylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, nonadecylamine, icosylamine, alicyclic monoamines such as cyclohexylamine, methylcyclohexylamine, benzylamine, and and aromatic monoamines such as β-phenylethylamine. Two or more of the above-mentioned terminal modification compounds can be used.

  Moreover, as a raw material which gives a polyamide resin, the above-mentioned amino acid, lactam, and "the mixture of diamine and dicarboxylic acid" are illustrated.

  When the terminal-modified polyamide resin is produced by reacting the raw material of the polyamide resin and the terminal-modifying compound at the time of polymerization, the reaction is performed at a temperature lower than the melting point of the polyamide resin and a melt polymerization method in which the reaction is performed at a temperature higher than the melting point of the polyamide resin. Any of the solid phase polymerization methods can be used. On the other hand, when the terminal-modified polyamide resin is produced by melt-kneading the polyamide resin and the terminal-modifying compound, the melt-kneading temperature is higher by 10 ° C. or more and 40 ° C. or less than the melting point (Tm) of the polyamide resin. It is preferable to react. For example, when melt-kneading using an extruder, it is preferable that the cylinder temperature of an extruder shall be the said range. By setting the melt kneading temperature within this range, it is possible to efficiently bond the terminal of the polyamide resin and the terminal modifying compound while suppressing the volatilization of the terminal modifying compound and the decomposition of the polyamide resin.

  The type of the reinforcing fiber (B) used in the embodiment of the present invention is not particularly limited, and glass fiber, polyacrylonitrile (PAN) -based or pitch-based carbon fiber, organic fiber such as aramid fiber, alumina fiber, silicon carbide fiber High-strength and high-modulus fibers such as boron fibers and metal fibers are used. Two or more of these reinforcing fibers may be used.

  The reinforcing fiber in the present invention can improve mechanical properties such as mechanical properties due to the fiber reinforcing effect on the polyamide resin. Furthermore, when the reinforcing fiber has unique characteristics such as conductivity and thermal conductivity, those properties that cannot be achieved with a single polyamide resin can also be imparted. Glass fiber or carbon fiber is preferable as the reinforcing fiber (B) from the viewpoint of further improving the mechanical properties and reducing the weight of the molded product. For the purpose of imparting electrical conductivity, reinforcing fibers coated with a metal such as nickel, copper, or ytterbium may be used.

  The average fiber diameter of the reinforcing fibers is not particularly limited, but is preferably 3 to 20 μm from the viewpoint of mechanical properties and surface appearance of the molded product. Although there is no restriction | limiting in particular in the number of single fibers at the time of setting it as a reinforced fiber bundle, 100-50,000 are preferable and 1,000-25,000 are more preferable from a viewpoint of productivity. Further, the reinforcing fiber may be treated with a known coupling agent or sizing agent for the purpose of improving the adhesion between the reinforcing fiber and the polyamide resin or preventing the reinforcing fiber from fuzzing. . Examples of coupling agents include silane coupling agents, aluminate coupling agents, titanate coupling agents, and the like. Examples of the sizing agent include an epoxy resin, a phenol resin, polyethylene glycol, polyurethane, polyester, an emulsifier, or a surfactant. Two or more of these may be used. The treatment amount of the coupling agent or sizing agent is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the reinforcing fibers.

  In the embodiment of the present invention, the content of the reinforcing fiber is 5 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the polyamide resin (A). If the amount is less than 5 parts by mass, the reinforcing effect by the fibers is small. 10 mass parts or more are preferable and 15 mass parts or more are more preferable. On the other hand, when it exceeds 150 parts by mass, the productivity of the long fiber reinforced polyamide resin composition pellets is low and the fluidity is also lowered. 120 parts by mass or less is preferable, and 100 parts by mass or less is more preferable.

The long fiber reinforced polyamide resin composition pellets of the embodiment of the present invention are formed by arranging the reinforcing fibers substantially in the same length as the pellets and arranging the reinforcing fibers in the longitudinal direction of the pellets. Here, “arranged in the longitudinal direction of the pellet” indicates a state in which the long axis of the reinforcing fiber and the long axis of the pellet are oriented in the same direction. The angle formed by the axes is preferably 20 ° or less, more preferably 10 ° or less, and further preferably 5 ° or less. Further, “substantially the same as the length of the pellet” indicates that the reinforcing fiber is intentionally cut inside the pellet, or the reinforcing fiber that is significantly shorter than the entire length of the pellet is not included.
When the reinforcing fiber has substantially the same length as the pellet, the reinforcing fiber length in the molded product can be increased, and the mechanical properties can be further improved. It is preferable that the long fiber reinforced polyamide resin composition pellets of the embodiment of the present invention maintain substantially the same cross-sectional shape in the longitudinal direction and are continuous. Further, the length in the longitudinal direction of the long fiber reinforced polyamide resin composition pellets is preferably 3 to 20 mm. When the length of the long fiber reinforced polyamide resin composition pellets in the longitudinal direction is 3 mm or more, the productivity of the pellets is easily improved. 5 mm or more is more preferable. On the other hand, when the length of the long fiber reinforced polyamide resin composition pellets in the longitudinal direction is 20 mm or less, the pellets are hardly bridged during molding. 15 mm or less is more preferable.

  The long fiber reinforced polyamide resin composition pellets of the embodiment of the present invention further have a thermoplastic polymer (C) having a melt viscosity of 0.01 to 20 Pa · s at 200 ° C. (hereinafter referred to as “thermoplastic polymer (C)”). In some cases). By containing the thermoplastic polymer (C), the dispersibility of the reinforcing fibers can be further improved during the production of the long fiber reinforced polyamide resin composition pellets and the molding thereof, and the fluidity during the molding can be further improved. . When the melt viscosity at 200 ° C. of the thermoplastic polymer (C) is 0.01 Pa · s or more, the mechanical strength of the molded product can be further improved. The melt viscosity of the thermoplastic polymer is preferably 0.05 Pa · s or more, and more preferably 0.1 Pa · s or more. On the other hand, if the melt viscosity at 200 ° C. of the thermoplastic polymer (C) is 20 Pa · s or less, the dispersibility of the reinforcing fibers can be further improved during the production of the long fiber reinforced polyamide resin composition pellets and the molding thereof. Can do. The melt viscosity of the thermoplastic polymer is preferably 15 Pa · s or less, more preferably 10 Pa · s or less. Here, the melt viscosity at 200 ° C. of the thermoplastic polymer (C) can be measured with a viscoelasticity measuring device at 0.5 Hz using a 40 mm parallel plate.

  In the long fiber reinforced polyamide resin composition pellets of the embodiment of the present invention, the thermoplastic polymer (C) preferably has a high affinity for the polyamide resin. By selecting the thermoplastic polymer (C) having a high affinity with the polyamide resin, it is compatible with the polyamide resin at the time of manufacturing and molding the long fiber reinforced polyamide resin composition pellets. Dispersibility can be further improved. The thermoplastic polymer (C) is preferably a phenol polymer, and examples thereof include phenol novolac resins, cresol novolac resins, alkylbenzene-modified phenol resins, cashew-modified phenol resins, terpene-modified phenol resins, and terpene phenol resins. Two or more of these may be used.

  The content of the thermoplastic polymer (C) is preferably 0.1 parts by mass or more and 65 parts by mass or less with respect to 100 parts by mass of the polyamide resin (A). If content of a thermoplastic polymer (C) is 0.1 mass part or more, the dispersibility of a reinforced fiber and the fluidity | liquidity at the time of shaping | molding can be improved more. On the other hand, if the content of the thermoplastic polymer (C) is 65 parts by mass or less, the mechanical properties of the molded product can be further improved.

  Moreover, it is preferable that the thermoplastic polymer (C) adheres to the reinforcing fiber (B). Specifically, the thermoplastic polymer (C) is preferably in a form that is pre-impregnated with the reinforcing fiber (B). With this form, during the production of the long fiber reinforced polyamide resin composition pellets, The dispersibility of the reinforcing fiber in the polyamide resin can be expressed most efficiently.

  In the long fiber reinforced polyamide resin composition pellets of the present invention, as long as the effects of the present invention are not impaired, stabilizers, mold release agents, ultraviolet absorbers, colorants, flame retardants, flame retardant aids, anti-dripping agents, Addition of lubricants, fluorescent brighteners, phosphorescent pigments, fluorescent dyes, flow modifiers, impact modifiers, crystal nucleating agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents, infrared absorbers, photochromic agents, etc. Agents, non-fibrous fillers other than reinforcing fibers, and thermosetting resins can be blended.

  Examples of the stabilizer include an antioxidant and a light stabilizer, and examples include a copper compound such as cuprous iodide. By blending these stabilizers, a molded product having excellent mechanical properties, moldability, heat resistance and durability can be obtained.

  Examples of the release agent include fatty acids, fatty acid metal salts, oxy fatty acids, fatty acid esters, aliphatic partially saponified esters, paraffins, low molecular weight polyolefins, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, and modified silicones. be able to. By blending these release agents, a molded product having excellent mechanical properties, moldability, heat resistance and durability can be obtained.

  Examples of the flame retardant include bromine-based flame retardant, chlorine-based flame retardant, phosphorus-based flame retardant, nitrogen compound-based flame retardant, silicone-based flame retardant, and other inorganic flame retardants. From the viewpoint of further improving flame retardancy and mechanical properties, it is a preferred embodiment to combine two or more of the above flame retardants.

  As the non-fibrous filler other than the reinforcing fibers, for example, any filler such as a plate, powder, and granule can be used. Specific examples of such fillers include metal silicates such as talc, zeolite, sericite, mica, kaolin, clay, pyrophyllite, and bentonite, metals such as magnesium oxide, alumina, zirconium oxide, and iron oxide. Oxides, carbonates such as calcium carbonate, magnesium carbonate, dolomite, metal sulfates such as calcium sulfate and barium sulfate, glass beads, ceramic beads, boron nitride, calcium phosphate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, etc. Metal hydroxide, glass flake, glass powder, glass balloon, carbon black, silica, graphite, montmorillonite, beidellite, nontronite, saponite, hectorite, soconite and other smectite clay minerals, vermiculite, halo Layered silicic acid such as various clay minerals such as site, kanemite, kenyanite, zirconium phosphate, titanium phosphate, swellable mica such as Li type fluorine teniolite, Na type fluorine teniolite, Na type tetrasilicon fluorine mica, and Li type tetrasilicon fluorine mica Examples include salt. Two or more of these can be blended.

  As an example of the form of the long fiber reinforced polyamide resin composition pellet of the embodiment of the present invention, examples of the cross-sectional shape of the long fiber reinforced polyamide resin composition pellet are shown in FIGS. The cross-sectional shape of the long fiber reinforced polyamide resin composition pellets is a polyamide resin composition obtained by melt-kneading the polyamide resin (A) containing the terminal-modified polyamide resin (a) and other components as necessary, and reinforcing fibers ( B) is not limited to the one shown in the figure, but as shown in FIG. 1, a form in which the reinforcing fibers 2 are dispersed in the polyamide resin composition 1 or shown in FIG. Thus, the form arrange | positioned so that the polyamide resin composition 1 coat | covers the circumference | surroundings of the composite_body | complex 3 which consists of a reinforced fiber and a thermoplastic polymer (C) is preferable. The polyamide resin composition 1 may be a polyamide resin (A) containing a terminal-modified polyamide resin (a), or may be a polyamide resin composition in which other components are blended with the polyamide resin (A) as necessary.

  As shown in FIG. 1 and FIG. 2, the form in which the polyamide resin composition is arranged on the outer peripheral surface of the long fiber reinforced polyamide resin composition pellet is such that the reinforcing fiber is not exposed and the long fiber reinforced polyamide resin composition pellet is formed. Suppresses falling off of reinforcing fibers and is superior in handling. Examples of the cross-sectional shape of the long fiber reinforced polyamide resin composition pellet include a circle, an ellipse, and a polygon. The longitudinal direction of the long fiber reinforced polyamide resin composition pellets may be continuous while maintaining substantially the same cross-sectional shape.

As a method for producing a long fiber reinforced polyamide resin composition pellet of an embodiment of the present invention, a reinforcing fiber bundle is passed through a die filled with a molten resin attached to the tip of an extruder, and is squeezed with a bar and widened.・ Methods of impregnating the reinforcing fiber bundle with resin by operations such as repeated focusing, applying pressure and vibration, etc., or passing the reinforcing fiber bundle through a coating die for the wire coating method, and the molten resin around the reinforcing fiber bundle Any known method such as extrusion coating may be used.
Extruder equipped with a die filled with a space filled with molten resin at the tip and a roll or bar for resin impregnation (hereinafter sometimes referred to as “crosshead die”) or a coating die for the wire coating method The end-modified polyamide resin and, if necessary, other components are melt-kneaded and impregnated with a terminal-modified polyamide resin composition melted in a bundle of reinforcing fibers with a crosshead die attached to the tip or a coating die for the wire coating method. Or the method of coat | covering is mentioned.

  The composite of the reinforcing fiber and the polyamide resin obtained by such a method is cut to a predetermined length with a strand cutter, so that the length of the reinforcing fiber is substantially the same as the length of the pellet and the reinforcing fiber is a pellet. The long fiber reinforced polyamide resin composition pellets arranged in the longitudinal direction can be obtained.

  Moreover, when the long fiber reinforced polyamide resin composition pellet of the embodiment of the present invention contains the thermoplastic polymer (C), it is preferable that the thermoplastic polymer (C) is impregnated in advance with the reinforcing fibers. A method for obtaining such a composite is not particularly limited. For example, a step of bringing a thermoplastic polymer (C) into contact with a reinforcing fiber in a molten state at 100 to 300 ° C. (hereinafter, step (i)) And a step of heating and impregnating the reinforcing fiber in contact with the thermoplastic polymer (C) (hereinafter sometimes referred to as step (ii)), and the like. Is mentioned.

  In the step (i), the method of supplying the thermoplastic polymer (C) and bringing it into contact with the reinforcing fiber is not particularly limited. For example, any method used when an oil agent, a sizing agent, or a matrix resin is applied to the reinforcing fiber. The method can be used. Among these, dipping or coating is preferably used. The dipping is a method in which the thermoplastic polymer (C) is supplied to the melting bath by a pump and the reinforcing fibers are passed through the melting bath. The thermoplastic polymer (C) can be attached to the reinforcing fiber by immersing the reinforcing fiber in the molten bath of the thermoplastic polymer (C). Further, the coating is a method of applying the thermoplastic polymer (C) to the reinforcing fiber using a coating means such as a reverse roll, a normal rotation roll, a kiss roll, a spray, or a curtain. Here, the reverse roll, the forward rotation roll, and the kiss roll are a method in which the thermoplastic polymer (C) melted by the pump is supplied to the roll, and the melt of the thermoplastic polymer (C) is applied to the reinforcing fiber. is there. Furthermore, the reverse roll is a method in which two rolls are rotated in opposite directions and a molten thermoplastic polymer (C) is applied onto the roll. In this method, the thermoplastic polymer (C) is rotated and melted on a roll. Usually, in the reverse roll and the positive rotation roll, a method is used in which the reinforcing fibers are sandwiched and a roll is further provided to securely adhere the thermoplastic polymer (C). On the other hand, the kiss roll is a method for adhering the thermoplastic polymer (C) only by contact between the reinforcing fiber and the roll. Therefore, the kiss roll is preferably used when the viscosity is relatively low. However, regardless of which roll method is used, a predetermined amount of the heat-melted thermoplastic polymer (C) is applied and run while adhering the reinforcing fibers. Thus, a predetermined amount of the thermoplastic polymer (C) can be adhered per unit length of the fiber. The spray is a method that uses the principle of spraying, and is a method in which the molten thermoplastic polymer (C) is sprayed on the reinforcing fiber in the form of a mist. The curtain is a method of spraying the molten thermoplastic polymer (C) from the small holes. It is a method of applying by dropping naturally or a method of applying by dropping from a melting tank. Since it is easy to adjust the amount necessary for coating, loss of the thermoplastic polymer (C) can be reduced.

  Moreover, 100-300 degreeC is preferable for the melting temperature (temperature in a fusion bath) at the time of supplying a thermoplastic polymer (C). When the melting temperature is 100 ° C. or higher, the viscosity of the thermoplastic polymer (C) can be moderately suppressed, and uneven adhesion can be suppressed. 150 degreeC or more is more preferable. On the other hand, if the melting temperature is 300 ° C. or lower, the thermal decomposition of the thermoplastic polymer (C) can be suppressed even when produced for a long time. 250 degrees C or less is more preferable. By bringing the thermoplastic polymer (C) into contact with the reinforcing fiber in a molten state at 100 to 300 ° C., it can be stably supplied.

  Next, the step of heating the reinforcing fibers in contact with the thermoplastic polymer (C) obtained in the step (i) to impregnate the thermoplastic polymer (C) in the bundle of reinforcing fibers (step (step ( ii)) will be described. Specifically, for the reinforcing fiber in contact with the thermoplastic polymer (C), at a temperature at which the thermoplastic polymer (C) melts, tension is applied with a roll or a bar, and widening and focusing are repeated. In this step, the thermoplastic polymer (C) is impregnated to the inside of the reinforcing fiber by an operation such as applying pressure or vibration. As a more specific example, there can be mentioned a method of performing widening by passing the reinforcing fiber so as to contact the surface of a plurality of heated rolls and bars. Among them, a drawing base, a drawing roll, a roll press, a double A method of impregnation using a belt press is preferably used. Here, the squeezing base is a base whose diameter decreases in the direction of travel, and scrapes off the excessively attached thermoplastic polymer (C) while concentrating the reinforcing fibers, and at the same time impregnation. It is a mouthpiece to encourage. The squeezing roll is a roller that promotes impregnation at the same time as scraping off the excessively attached thermoplastic polymer (C) by applying tension to the reinforcing fiber with a roller. The roll press is a device that continuously removes the air inside the reinforcing fiber by the pressure between the two rolls and at the same time promotes the impregnation of the thermoplastic polymer (C). It is a device that promotes impregnation of the thermoplastic polymer (C) by pressing from above and below via a belt.

  In the step (ii), it is preferable that 80 to 100% by weight of the supply amount of the thermoplastic polymer (C) is impregnated in the reinforcing fiber. If it is 80 weight% or more, generation | occurrence | production of the volatile component resulting from the thermoplastic polymer (C) in process (ii) can be suppressed, and the void generation | occurrence | production inside the bundle | flux of a reinforced fiber can be suppressed. More preferably, it is 85-100 weight%, More preferably, it is 90-100 weight%.

  Moreover, in process (ii), it is preferable that the maximum temperature of a thermoplastic polymer (C) is 150-350 degreeC. When the maximum temperature is 150 ° C. or higher, the thermoplastic polymer (C) can be sufficiently melted and impregnated more effectively. 180 degreeC or more is more preferable. On the other hand, if the maximum temperature is 350 ° C. or lower, an undesirable side reaction such as a decomposition reaction of the thermoplastic polymer (C) can be suppressed. 300 degrees C or less is more preferable, and 250 degrees C or less is further more preferable.

  Although it does not specifically limit as a heating method in process (ii), Specifically, the method of using the heated chamber, the method of performing a heating and pressurization simultaneously using a hot roller, etc. can be illustrated.

  A bundle of reinforcing fibers impregnated with the thermoplastic polymer (C) obtained through the steps (i) and (ii) described above is used as a cross-head die or a coating die for a wire coating method, and a terminal-modified polyamide resin is necessary. By impregnating and / or covering the polyamide resin (A) obtained by melt-kneading the other components with the above, more preferable long fiber reinforced polyamide resin composition pellets can be obtained.

  The long fiber reinforced polyamide resin composition pellets of the present invention are usually produced as described above, and various molded products can be produced by injection molding the pellets. The injection molding method is not only a normal injection molding method, but also an injection compression molding, an injection press molding, a gas assist injection molding, a foam molding (including those by injection of a supercritical fluid), an insert molding, depending on the purpose. A molded product can be obtained using an injection molding method such as in-mold coating molding, heat insulating mold molding, rapid heating / cooling mold molding, two-color molding, sandwich molding, and ultrahigh-speed injection molding. The advantages of these various molding methods are already widely known. In addition, either a cold runner method or a hot runner method can be selected for forming.

  The molded article comprising the long fiber reinforced polyamide resin composition pellets of the present invention is compared with a molded article obtained by molding a general compound type fiber reinforced polyamide resin composition pellet (short fiber reinforced polyamide resin composition pellet). However, the fiber length of the reinforcing fiber in the molded product is long, and the mechanical properties are excellent. It is preferable that the weight average fiber length of the reinforcing fiber (B) in the molded product is 0.3 to 5.0 mm, and the weight average fiber length of the reinforcing fiber in the molded product is in this preferable range. Mechanical characteristics and shape followability of the molded product can be obtained.

Here, the weight average fiber length of the reinforcing fibers in the molded product using the long fiber reinforced polyamide resin composition pellets of the present invention is obtained by baking the obtained molded product at 500 ° C. for 1 hour, and the obtained ash content. Was dispersed in water, filtered, the residue was observed with an optical microscope, and the length of 1000 fibers was measured to obtain a weight average fiber length. Specifically, an ISO 3167A type multi-purpose test piece is molded using the long fiber reinforced polyamide resin composition pellets, and the molded product is cut out and placed in a crucible of about 3 g until no flammable gas is generated on the electric stove. After steaming, only the reinforcing fiber residue is obtained by further baking for 1 hour in an electric furnace set at a temperature of 500 ° C. Observe an image of the residue magnified 50 to 100 times with an optical microscope, measure the length of 1,000 randomly selected, and use the measured value (mm) (2 decimal places are significant figures) The weight average fiber length (Lw) is calculated.
Weight average fiber length (Lw) = Σ (Wi × Li) / ΣWi
= Σ (πri ² × Li × ρ × ni × Li) / Σ (πri ² × Li × ρ × ni)
When the fiber diameter ri and the density ρ are constant, the above expression is simplified and becomes the following expression.
Weight average fiber length (Lw) = Σ (Li ² × ni) / Σ (Li × ni)
Li: Fiber length of reinforcing fiber ni: Number of reinforcing fibers with fiber length Li Wi: Weight of reinforcing fiber ri: Fiber diameter of reinforcing fiber ρ: Density of reinforcing fiber.

  Molded articles using the long fiber reinforced polyamide resin composition pellets of the present invention are used for various applications such as automobile parts, electrical / electronic parts, building components, sports equipment parts, various containers, daily necessities, daily life goods and sanitary goods. be able to.

  Specific applications include air flow meters, air pumps, thermostat housings, engine mounts, ignition hobbins, ignition cases, clutch bobbins, sensor housings, idle speed control valves, vacuum switching valves, ECU housings, vacuum pump cases, inhibitor switches, rotations Sensor, acceleration sensor, distributor cap, coil base, actuator case for ABS, radiator tank top and bottom, cooling fan, fan shroud, engine cover, cylinder head cover, oil cap, oil pan, oil filter, fuel cap, fuel strainer , Distributor cap, vapor canister Housing, air cleaner housing, timing belt cover, brake booster parts, various cases, various tubes, various tanks, various hoses, various clips, various valves, various pipes, automotive underhood parts, torque control lever, safety belt parts, Car interior parts such as register blade, washer lever, window regulator handle, knob of window regulator handle, passing light lever, sun visor bracket, various motor housings, roof rail, fender, garnish, bumper, door mirror stay, spoiler, food louver, Wheel covers, wheel caps, grill apron cover frames, lamp reflectors, lamp bezels, door handles, etc. Exterior parts for vehicles, relay cases, coil bobbins, optical pickup chassis, motor cases, laptop housings, chassis and internal parts, CRT display housings and internal parts, printer housings and internal parts, mobile phones, mobile PCs, handheld mobiles, etc. Mobile terminal housing, chassis and internal parts, recording medium (CD, DVD, PD, FDD, etc.) drive housing, chassis and internal parts, copier housing, chassis and internal parts, facsimile housing, chassis and internal parts, Electric and electronic parts such as parabolic antennas, VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, video cameras, projectors, etc. Optical recording of equipment parts, laser disc (registered trademark), compact disc (CD), CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, Blu-ray disc, etc. Media substrates, lighting parts and housings, chassis parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts and other household and office electrical parts, electronic musical instruments, home game machines, portable game machine housings, chassis And internal parts, various gears, various cases, sensors, LEP lamps, connectors, sockets, resistors, relay cases, switches, coil bobbins, capacitors, variable capacitor cases, optical pickups, oscillators, various terminal boards, transformers, plugs, prints Wiring board, tuner, speaker, my Lophone, headphone, small motor, magnetic head base, power module, semiconductor, liquid crystal, FDD carriage, FDD chassis, motor brush holder, transformer member, coil bobbin and other electric / electronic parts, sash door, blind curtain parts, piping joint, curtain Liners, blind parts, gas meter parts, water meter parts, water heater parts, roof panels, heat insulation walls, adjusters, plastic bundles, ceiling fishing gear, stairs, doors, floors and other construction parts, concrete formwork and other civil engineering parts, fishing rods Parts, reel housing and chassis parts, lure parts, cooler box parts, golf club parts, tennis, badminton, squash racket parts, ski parts, ski stock parts, bicycle frames, pedals , Parts such as front forks, handlebars, cranks, seat pillars, wheels, boat oars, sports helmets, fence components, golf tees, sports equipment parts such as kendo armor (face) and bamboo swords, gears, screws, Springs, bearings, levers, key stems, cams, ratchets, rollers, water supply parts, toy parts, cable ties, clips, fans, pipes, cleaning jigs, motor parts, microscopes, binoculars, cameras, watches and other mechanical parts, seedlings Agricultural materials such as pots, vegetation piles, agricultural bean clasps, medical supplies such as fracture reinforcements, containers such as trays, blisters, knives, forks, spoons, tubes, plastic cans, pouches, containers, tanks, baskets, etc. Tableware, hot fill containers, microwave cooking containers, cosmetic containers, IC trays, stationery Useful as drainage filter, bag, chair, table, cooler box, kumade, hose reel, planter, hose nozzle, dining table, desk surface, furniture panel, kitchen cabinet, pen cap, and gas lighter. In particular, it is useful as an interior part for automobiles, exterior parts for automobiles, sports equipment members, housings for various electric / electronic parts, chassis and internal parts.

  Next, an Example is shown and it demonstrates still more concretely about the long fiber reinforced polyamide resin composition pellet of this invention, and its molded article. Characteristic evaluation in each example and each comparative example was performed according to the following method.

[material]
In the examples and comparative examples, the following raw materials were used.
・ Ε-caprolactam: Wako Pure Chemical Industries, Ltd. Wako special grade ・ Hexamethylenediamine: Wako Pure Chemical Industries, Ltd. Wako first grade ・ Sebacic acid: Wako Pure Chemical Industries, Ltd. Wako first grade.

[Compound for terminal modification represented by general formula (III)]
A methoxypoly (ethylene glycol) poly (propylene glycol) amine represented by the following structural formula (Chemical Formula 1): “JEFFAMINE” (registered trademark) M1000 (number average molecular weight Mn1000) manufactured by HUNTSMAN.

  -Methoxypoly (ethylene glycol) poly (propylene glycol) amine represented by the following structural formula (Chemical Formula 2): “JEFFAMINE” (registered trademark) M2070 (number average molecular weight Mn2000) manufactured by HUNTSMAN.

  A methoxyethylene glycol poly (propylene glycol) amine represented by the following structural formula (Chemical Formula 3): “JEFFAMINE” (registered trademark) M600 (number average molecular weight Mn600) manufactured by HUNTSMAN.

[Compound for terminal modification represented by formula (IV)]
-Benzoic acid: Special reagent grade manufactured by Wako Pure Chemical Industries, Ltd.-Stearic acid: Special reagent grade manufactured by Wako Pure Chemical Industries, Ltd.

[Reinforcing fiber (B)]
<B-1> Carbon fiber (“Torayca” (registered trademark) T700SC-24K manufactured by Toray Industries, Inc.), diameter 7 μm, number of single fibers 24,000 <B-2> glass fiber (manufactured by Nippon Electric Glass Co., Ltd.) ER2400 T-423N), diameter 17 μm, number of single fibers 4,000.

[Thermoplastic polymer (C)]
Terpene phenol resin (YS Polystar K125 manufactured by Yashara Chemical Co., Ltd., melt viscosity at 200 ° C. of 0.3 Pa · s).

[Relative viscosity (ηr)]
The relative viscosity was measured at 25 ° C. using an Ostwald viscometer for a 98% sulfuric acid solution having a resin concentration of 0.01 g / ml of the polyamide resin obtained in Examples and Comparative Examples.

[Molecular weight]
2.5 mg of the polyamide resin obtained in Examples and Comparative Examples was dissolved in 4 ml of hexafluoroisopropanol (0.005N-sodium trifluoroacetate added), and the resulting solution was filtered through a 0.45 μm filter. Using the obtained solution, the number average molecular weight (Mn) and the weight average molecular weight (Mw) (weight average molecular weight before melt residence) were measured by GPC measurement. The measurement conditions are as follows.
・ Pump: e-Alliance GPC system (manufactured by Waters)
Detector: Differential refractometer Waters 2414 (manufactured by Waters)
Column: Shodex HFIP-806M (2) + HFIP-LG
-Solvent: hexafluoroisopropanol (0.005N-sodium trifluoroacetate added)
・ Flow rate: 1 ml / min ・ Sample injection amount: 0.1 ml
・ Temperature: 30 ℃
-Molecular weight reference material: polymethyl methacrylate.

[Amino terminal group amount [NH ₂ ]]
0.5 g of the polyamide resin obtained in Examples and Comparative Examples is precisely weighed, and 25 ml of a phenol / ethanol mixed solution (mixing ratio (mass ratio): 83.5 / 16.5 mass ratio) is added and dissolved at room temperature. Then, titration with 0.02 N hydrochloric acid was performed using thymol blue as an indicator to determine the amino terminal group amount (mol / t).

[Amount of carboxyl end group [COOH]
After accurately weighing 0.5 g of the polyamide resin obtained in Examples and Comparative Examples, adding 20 ml of benzyl alcohol and dissolving at 195 ° C., 0.02 N ethanol solution of potassium hydroxide using phenolphthalein as an indicator To determine the carboxyl end group amount (mol / t).

[Identification of terminal structure and determination of content of terminal structure of general formula (I) and content of terminal structure of general formula (II)]
The polyamide resin obtained by the Examples and Comparative Examples, was carried out the ¹ H-NMR measurement using a FT-NMR JNM-AL400 manufactured by JEOL Corporation. First, a solution having a sample concentration of 50 mg / mL was prepared using deuterated sulfuric acid as a measurement solvent. ¹ H-NMR measurement of the polyamide resin was carried out at a total number of 256 times. Peaks derived from the R ¹ and R ² moieties in the terminal structure represented by the general formula (I), peaks derived from the R ³ moiety in the terminal structure represented by the general formula (II), and derived from repeating structural units of the polyamide resin skeleton A peak was identified. The integrated intensity of each peak is calculated, and the content [I] (mol / mol) of the terminal structure represented by the general formula (I) in the polyamide resin is calculated from the calculated integrated intensity and the number of hydrogen atoms in each structural unit. t, mass%) (content before residence) and content [II] (mol / t, mass%) of the terminal structure represented by the general formula (II) were calculated.

[Thermal characteristics]
Using a differential scanning calorimeter (DSC Q20) manufactured by TA Instruments, 5-7 mg of polyamide resin obtained in Examples and Comparative Examples was weighed, and the temperature rising rate was 20 ° C. from a temperature of 20 ° C. in a nitrogen atmosphere. The temperature was raised to a temperature of 250 ° C./min. The peak of the endothermic peak that appears when the temperature was raised was defined as Tm (melting point).

[Melt viscosity]
The polyamide resins obtained in the examples and comparative examples were dried for 12 hours or more in a vacuum dryer at a temperature of 80 ° C. As a melt viscosity measuring device, a capillary flow meter (manufactured by Toyo Seiki Seisakusho Co., Ltd., Capillograph 1C type) is used, with an orifice having a diameter of 0.5 mm and a length of 5 mm, melting point + 60 ° C., shear rate 9728 sec ⁻¹ . Under the conditions, melt viscosity (melt viscosity before residence) was measured. However, in order to melt the polyamide resin, the measurement was performed after it was retained for 5 minutes. It shows that it has high fluidity, so that the value of this melt viscosity is small.

[Melt viscosity retention]
The polyamide resins obtained in the examples and comparative examples were dried for 12 hours or more in a vacuum dryer at a temperature of 80 ° C. Conditions using a capillary flow meter (Capillograph 1C type, manufactured by Toyo Seiki Seisakusho Co., Ltd.) with an orifice having a diameter of 0.5 mm and a length of 5 mm at a melting point of + 60 ° C. for 60 minutes and then a shear rate of 9728 sec ⁻¹ The melt viscosity (melt viscosity after residence) was measured. From the melt viscosity (melt viscosity before residence) and the melt viscosity (melt viscosity after residence) measured by the method described above, the melt viscosity retention [%] was calculated by (melt viscosity after residence / melt viscosity before residence) × 100.

[Weight average molecular weight retention]
The polyamide resins obtained in the examples and comparative examples were dried for 12 hours or more in a vacuum dryer at a temperature of 80 ° C. Using a capillary flow meter (Capillograph 1C type, manufactured by Toyo Seiki Seisakusho Co., Ltd.), melt residence was performed at an melting point of + 60 ° C. for 60 minutes with an orifice having a diameter of 0.5 mm and a length of 5 mm. About the polyamide resin after melt residence, the weight average molecular weight (Mw) (weight average molecular weight after residence) was measured by GPC measurement similar to the molecular weight measurement method described above. From the weight average molecular weight (weight average molecular weight before melting residence) and the weight average molecular weight (weight average molecular weight after residence) measured by the above-mentioned method, the weight average molecular weight by (weight average molecular weight after residence / weight average molecular weight before residence) × 100 Retention rate [%] was calculated.

[Retention rate of content of terminal structure represented by general formula (I)]
The polyamide resins obtained in the examples and comparative examples were dried for 12 hours or more in a vacuum dryer at a temperature of 80 ° C. Using a capillary flow meter (Capillograph 1C type, manufactured by Toyo Seiki Seisakusho Co., Ltd.), melt residence was performed at an melting point of + 60 ° C. for 60 minutes with an orifice having a diameter of 0.5 mm and a length of 5 mm. About the polyamide resin after melt residence, content [I] (mol / t) of the terminal structure represented by the general formula (I) in the polyamide resin by ¹ H-NMR measurement similar to the above-mentioned terminal structure content measuring method (Content after retention) was calculated. Content [I] (mol / t) (content before residence) of the terminal structure represented by the general formula (I) and content of the terminal structure represented by the general formula (I) measured by the method described above From [I] (mol / t) (content after residence), content retention was calculated by (content after residence / content before residence) × 100.

[Mass reduction rate]
The polyamide resins obtained in the examples and comparative examples were dried for 12 hours or more in a vacuum dryer at a temperature of 80 ° C. 20 mg of an arbitrary part was cut out, and using a thermogravimetric analyzer (Perkin Elmer, TGA7), held in a nitrogen gas atmosphere at a melting point of the polyamide resin + 60 ° C. for 40 minutes, and a mass reduction rate [%] before and after the heat treatment was measured. .

[Tensile breaking elongation]
The polyamide resins obtained in the examples and comparative examples were dried for 12 hours or more in a vacuum dryer at a temperature of 80 ° C. Using an IS55EPN injection molding machine manufactured by Toshiba Machine Co., Ltd., the cylinder temperature is the melting point (Tm) of the polyamide resin + 60 ° C., the mold temperature is 80 ° C., and the injection time and pressure holding time are combined for 10 seconds. A test piece for evaluation of ASTM No. 4 dumbbell having a test piece thickness of 1/25 inch (about 1.0 mm) was injection-molded under a molding cycle condition of 10 seconds. The obtained ASTM No. 4 dumbbell-shaped test piece was subjected to “Tensilon” (registered trademark) UTA-2.5T (manufactured by Orientec Co., Ltd.), in accordance with ASTM-D638 at 23 ° C. and in an atmosphere of 50% humidity. A tensile test was performed at a strain rate of 10 mm / min, and the tensile elongation at break was measured.

Example 1
A reaction vessel was charged with 20 g of ε-caprolactam, 20 g of ion-exchanged water, 1.6 g of “JEFFAMINE” (registered trademark) M1000, and 0.14 g of benzoic acid, and the atmosphere was replaced with nitrogen. The set temperature of the heater on the outer periphery of the reaction vessel was set to 290 ° C., and heating was started. After the internal pressure of the can reached 1.0 MPa, the internal pressure of the can was maintained at 1.0 MPa while releasing moisture out of the system, and the temperature was increased until the internal temperature of the can reached 240 ° C. After the internal temperature of the can reached 240 ° C., the set temperature of the heater was changed to 270 ° C., and the internal pressure of the can was adjusted to be normal pressure over 1 hour (internal temperature at the time of reaching normal pressure: 243 ° C. ). Continuously, nitrogen was allowed to flow in the can (nitrogen flow) for 240 minutes to obtain a terminal-modified polyamide 6 resin (maximum temperature reached: 253 ° C.). Subsequently, the obtained polyamide resin (terminal-modified polyamide 6 resin) was subjected to Soxhlet extraction with ion-exchanged water to remove unreacted ε-caprolactam and the terminal-modifying compound, and in a vacuum dryer at a temperature of 80 ° C. Dried for 12 hours. The polyamide resin thus obtained (terminal-modified polyamide 6 resin) has a relative viscosity of 1.81, a weight average molecular weight of 30,000, a melting point (Tm) of 220 ° C., and a melt viscosity of 5.5 Pa · s. there were. Further, the obtained polyamide resin contained a terminal-modified polyamide 6 resin having a structure represented by the following chemical formula 4 and a structure represented by the following chemical formula 5 at its ends. Table 1 shows the physical properties of the polyamide resin (terminal-modified polyamide 6 resin).

  Next, the cylinder temperature of a Nippon Steel Works TEX-30α type twin screw extruder (screw diameter 30 mm, L / D = 32) equipped with a crosshead die at the tip is 240 ° C., the cross head die temperature is 240 ° C., The screw rotation speed was set to 200 rpm, the terminal-modified polyamide 6 resin obtained above was supplied from the main feeder, and the reinforcing fiber <B-1> was placed in the crosshead die at the tip of 6 diameters 20 mm A pultrusion molding was carried out through the upper and lower rolls. With respect to 100 parts by mass of the terminal-modified polyamide 6 resin, the discharge amount of the resin was adjusted so that the reinforcing fiber content was as shown in Table 1, and the terminal fiber was impregnated with the terminal-modified polyamide 6 resin. The obtained composite of reinforced fiber and polyamide resin composition was cooled and then cut with a strand cutter to obtain 7 mm long fiber reinforced polyamide resin composition pellets.

  The long fiber reinforced polyamide resin composition pellets obtained above were dried in a vacuum dryer at a temperature of 80 ° C. for 12 hours, and then an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.) was used. 290 ° C, mold temperature: 80 ° C, back pressure at metering 5MPa, injection time and pressure holding time are combined 15 seconds, cooling time 15 seconds, ISO 3167A type multi-purpose test piece is molded, each characteristic under the following conditions Was measured. The results are shown in Table 1.

[Tensile strength]
The tensile strength was evaluated at 23 ° C. according to ISO 527-1 and -2.

[Shock resistance]
According to ISO179, Charpy impact strength (notched) was evaluated at 23 ° C.

[Fiber length]
3 g of ISO 3167A type multi-purpose test piece obtained by injection molding is cut out, put in a crucible, steamed until no flammable gas is generated on an electric stove, and then 1 in an electric furnace set at a temperature of 500 ° C. Baked for hours. Then, it disperse | distributed to ion-exchange water, filtered, the length of 1000 pieces chosen at random was measured, observing the residue with 50 time magnification with the optical microscope. The weight average fiber length (Lw) was calculated from the obtained measurement value (mm) (2 digits after the decimal point was significant) according to the following formula.
Weight average fiber length (Lw) = Σ (Li ² × ni) / Σ (Li × ni)
Li: Fiber length of fibrous filler ni: Number of fibrous fillers of fiber length Li.

[Liquidity]
The long fiber reinforced polyamide resin composition pellets obtained above were dried in a vacuum dryer at a temperature of 80 ° C. for 12 hours, and then an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.) was used. 260 ° C., mold temperature: 80 ° C., back pressure during measurement 5 MPa, injection pressure: 50 MPa, injection speed: 100 mm / sec, injection time 10 seconds, cooling time 10 seconds, spiral flow mold of 10 mm width × 2 mm thickness A spiral flow test piece having a width of 10 mm and a thickness of 2 mm was produced by injection molding using a mold. The flow length of five test pieces was measured, and the fluidity was evaluated from the average value. The longer the flow length, the better the fluidity.

(Examples 2-37, Comparative Examples 1-4)
After changing the raw materials to the compositions shown in Tables 1 to 5 and setting the pressure in the can to normal pressure, the time for keeping nitrogen flowing in the can (nitrogen flow time) was changed to the time shown in Tables 1 to 4. Except for this, a polyamide resin (terminal-modified polyamide 6 resin) was obtained in the same manner as in Example 1. Thereafter, fiber-reinforced polyamide resin composition pellets and test pieces were molded in the same manner as in Example 1, and each characteristic was evaluated. The results are shown in Tables 1-5.

  Here, the polyamide resins obtained in Examples 2 to 9, 14 to 28, and 32 to 35 contained a terminal-modified polyamide 6 resin having the same structure as that of Example 1 at its terminal.

  Further, the polyamide resins obtained in Examples 10 to 12 included a terminal-modified polyamide 6 resin having a structure represented by the following chemical formula 6 and a structure represented by the following chemical formula 5 at its ends.

  Further, the polyamide resin obtained in Example 13 contained a terminal-modified polyamide 6 resin having a structure represented by the following chemical formula 7 and a structure represented by the following chemical formula 5 at its ends.

  Moreover, the polyamide resin obtained in Examples 29 to 31 contained a terminal-modified polyamide 6 resin having a structure represented by the following chemical formula 4 at its terminal.

  In addition, the polyamide resins obtained in Examples 36 to 37 contained a terminal-modified polyamide 6 resin having a structure represented by the following chemical formula 4 and a structure represented by the following chemical formula 8 at its ends.

  Moreover, the polyamide 6 resin obtained in Comparative Examples 1 to 4 did not include the terminal-modified polyamide 6 resin, and was a resin having only an amino terminal group and a carboxyl terminal group.

(Example 38, Comparative Example 5)
The cylinder temperature of a TEX-30α type twin screw extruder (screw diameter 30 mm, L / D = 32) equipped with a coating die for the wire coating method at the tip is 240 ° C, the crosshead die temperature is 240 ° C, The screw speed was set to 200 rpm, and terminal-modified polyamide 6 resin produced in the same manner as in Example 1 (Comparative Example 2 for Comparative Example 5) was supplied from the main feeder.

  On the other hand, a liquid film in which the thermoplastic polymer (C) was heated and melted was formed on a roll heated to 170 ° C. A reverse roll was used to form a film having a constant thickness on the roll. A continuous amount of the reinforcing fiber <B-1> was passed through the roll while being in contact therewith, and a certain amount of the thermoplastic polymer (C) was adhered per unit length of the reinforcing fiber. The reinforcing fiber to which the thermoplastic polymer (C) was adhered was heated to 170 ° C., and alternately passed through the top and bottom of six 50 mm diameter rolls arranged in a straight line. By this operation, the thermoplastic polymer (C) was impregnated into the inside of the reinforcing fiber.

  Subsequently, the reinforcing fiber impregnated with the thermoplastic polymer (C) was passed through a coating die for wire coating method at the tip of the twin screw extruder, and was subjected to pultrusion molding. Table 4 (Table 5 for Comparative Example 5) The amount of the resin discharged was adjusted so that the blended amount of the resin was adjusted, and the terminal-modified polyamide resin was coated around the reinforcing fiber. The obtained composite of reinforcing fiber and terminal-modified polyamide resin was cooled and then cut with a strand cutter to obtain 7 mm long fiber-reinforced polyamide resin composition pellets. Then, the test piece was shape | molded similarly to Example 1, and each characteristic was evaluated. The results are shown in Table 4 (Table 5 for Comparative Example 5).

(Example 39)
Hexamethylenediamine 7.74 g, sebacic acid 13.46 g, ion-exchanged water 20 g, “JEFFAMINE” M1000 1.6 g, and benzoic acid 0.14 g were charged in a reaction vessel, sealed, and purged with nitrogen. The set temperature of the heater on the outer periphery of the reaction vessel was set to 290 ° C., and heating was started. After the internal pressure of the can reached 1.0 MPa, the internal pressure of the can was maintained at 1.0 MPa while releasing moisture out of the system, and the temperature was increased until the internal temperature of the can reached 240 ° C. After the can internal temperature reached 240 ° C., the heater set temperature was changed to 290 ° C., and the internal pressure of the can was adjusted to be normal pressure over one hour (can internal temperature when normal pressure reached: 243 ° C.). . Continuously, nitrogen was allowed to flow in the can (nitrogen flow) for 240 minutes to obtain a terminal-modified polyamide 610 resin (maximum temperature reached: 253 ° C.). Here, the obtained polyamide resin contained a terminal-modified polyamide 610 resin having a structure represented by the following chemical formula 4 and a structure represented by the following chemical formula 5 at its ends.

  Thereafter, fiber-reinforced polyamide resin composition pellets and test pieces were molded in the same manner as in Example 1, and each characteristic was evaluated. The results are shown in Table 4.

  Structural units different from the repeating structural units constituting the polymer main chain by comparison between Examples 1-31, 39 and Comparative Examples 1-3, Example 34 and Comparative Example 4, and Example 38 and Comparative Example 5 A molded product comprising a long-fiber-reinforced polyamide resin composition pellet containing a terminal-modified polyamide resin having a structure composed of a terminal group of a polymer and further containing reinforcing fibers in a specific range is excellent in tensile strength and impact strength. At the same time, the spiral flow flow length (fluidity) can be improved.

  Moreover, from the comparison between Example 29 and Example 30, the thermal stability during the melt residence of the polyamide resin is further improved by setting the content of the terminal structure represented by the general formula (I) within a specific range. At the same time, the tensile strength and Charpy impact strength of the molded product are further improved. Further, from the comparison between Example 29 and Example 31, by setting the content of the terminal structure represented by the general formula (I) within a specific range, the melt viscosity of the polyamide resin can be further reduced, and molding The fluidity of time improves. Since breakage of the reinforcing fiber can be suppressed, it can be seen that the weight average fiber length of the reinforcing fiber in the molded product can be kept long, and in particular, the Charpy impact strength is improved.

  From the comparison between Example 1 and Example 29, by containing the terminal structure represented by the general formula (II), the thermal stability at the time of melt residence of the polyamide resin is improved, and the fluidity at the time of molding is equivalent. The deterioration of the mechanical properties of the molded product can be further reduced.

From the comparison between Example 1 and Example 28, the content of the terminal structure represented by the general formula (II) is set to 5% by mass or less, thereby preventing a decrease in thermal stability at the time of melting residence of the polyamide resin. Furthermore, a decrease in the molecular weight of the polyamide resin and a decrease in mechanical properties of the obtained molded product are also suppressed.
Further, from the comparison between Example 1 and Example 27, the content of the terminal structure represented by the general formula (II) is 0.1% by mass or more, so that the thermal stability at the time of melt residence of the polyamide resin and It can be seen that the mechanical properties of the molded product are further improved.

  From the comparison between Example 9 and Example 14, Examples 2 and 23 and Example 15, the content [I] of the terminal structure represented by the general formula (I) and the terminal structure represented by the general formula (II) When the total amount ([I] + [II]) of the content [II] is 250 mol / t or less, the thermal stability during the melt residence of the polyamide resin is improved, and the mechanical properties of the molded product are further improved. Can be improved. On the other hand, from the comparison between Examples 1, 3 to 5, 8, 24, 26 and Example 16, the total amount of terminal structure ([I] + [II]) was set to 60 mol / t or more, so that the mechanical properties were increased. It can be seen that the fluidity can be further improved.

  Further, from the comparison between Examples 2 and 23 and Examples 17 and 19, and Examples 1, 26 and Example 18, the molar ratio ([I] / [II]) was set to 2.5 or less at the time of molding. It is possible to improve the mechanical properties of the molded product while maintaining the same fluidity. On the other hand, from the comparison between Examples 2 and 23 and Example 21, Examples 1, 26 and Example 20, the melting of the polyamide resin was achieved by setting the molar ratio ([I] / [II]) to 0.5 or more. It can be seen that the stability during residence and the mechanical properties and fluidity of the molded product can be further improved.

Further, from the comparison between Example 7 and Example 22, the total amount of the amino terminal group amount [NH ₂ ] and the carboxyl terminal group amount [COOH] is set to 50 mol / t or more, so that the heat at the time of melting residence of the polyamide resin is increased. It can be seen that the stability and especially the Charpy impact strength of the molded product can be improved. On the other hand, from the comparison between Example 2 and Examples 23 and 25, the total amount of amino terminal group amount [NH ₂ ] and carboxyl terminal group amount [COOH] was set to 150 mol / t or less, whereby mechanical properties and fluidity were achieved. It can be seen that this can be further improved.

Further, from comparison between Examples 1, 5, 8 and Example 24, it can be seen that the Charpy impact strength of the molded product can be particularly improved by setting the molar ratio [NH ₂ ] / [COOH] to 0.5 or more. . On the other hand, from comparison between Examples 1, 5, 8 and Example 26, it can be seen that by setting the molar ratio [NH ₂ ] / [COOH] to 2.5 or less, particularly the Charpy impact strength of the molded product can be further improved. .

  Further, from the comparison between Example 1 and Example 38, by containing the thermoplastic polymer (C) in the long fiber reinforced polyamide resin composition pellets containing the terminal-modified polyamide 6 resin in a specific range, it is possible to obtain It can be seen that the tensile strength, Charpy impact strength and fluidity can be further improved.

1 Polyamide resin (A) containing terminal-modified polyamide resin (a) (or polyamide resin composition containing terminal-modified polyamide resin (a) and other components)
2 Reinforcing fiber (B)
3 Composite composed of reinforcing fiber (B) and thermoplastic polymer (C) attached to reinforcing fiber (B)

Claims (15)

A long fiber reinforced polyamide resin composition pellet containing a polyamide resin (A) and a reinforcing fiber (B),
The polyamide resin (A) contains a terminal-modified polyamide resin (a),
The terminal-modified polyamide resin (a) is a resin having a structure composed of a structural unit different from the repeating structural unit constituting the main chain of the polymer in the terminal group of the polymer,
For 100 parts by mass of the polyamide resin (A),
Including 5-150 parts by mass of reinforcing fiber (B),
The length of the reinforcing fiber (B) is substantially the same as the length of the pellet, and the reinforcing fiber (B) is arranged in the longitudinal direction of the pellet.
Long fiber reinforced polyamide resin composition pellets. The terminal-modified polyamide resin (a) contains a polyamide resin having a terminal structure represented by the following general formula (I),
The long fiber reinforced polyamide resin composition pellets according to claim 1, wherein the content of the terminal structure represented by the following general formula (I) with respect to the polyamide resin (A) is 1% by mass or more and 20% by mass or less.
_{^{-X- (R 1 -O) m -R}} 2 (I)
(In the above general formula (I), m represents a range of 2 to 100. R ¹ is a divalent hydrocarbon group having 2 to 10 carbon atoms, and R ² is a monovalent hydrocarbon having 1 to 30 carbon atoms. represents groups respectively.-X- is _{-NH -, - N (CH 3} ) - or - (C = O) -. represents the m ^{R 1} contained in the general formula (I) and are either the same or different May be.) The terminal-modified polyamide resin (a) further contains a polyamide resin having a terminal structure represented by the following general formula (II):
The long fiber reinforced polyamide resin composition pellets according to claim 2, wherein the content of the terminal structure represented by the following general formula (II) with respect to the polyamide resin (A) is 0.1 mass% or more and 5 mass% or less.
-YR ³ (II)
(In the general formula (II), R ³ represents a monovalent hydrocarbon group having 1 to 30 carbon atoms. In the general formula (I), —X— is —NH— or —N (CH ₃ ) —. In this case, -Y- in the general formula (II) represents-(C = O)-, and when -X- in the general formula (I) is-(C = O)-, the general formula (II) —Y— in — represents —NH— or —N (CH ₃ ) —. The said reinforced fiber (B) is a glass fiber or a carbon fiber, The long fiber reinforced polyamide resin composition pellet in any one of Claims 1-3 characterized by the above-mentioned. The terminal-modified polyamide resin (a) contains a terminal-modified polyamide resin having a terminal structure represented by the general formula (I) and a terminal-modified polyamide resin having a terminal structure represented by the general formula (II). ,
The total of the content of the terminal structure represented by the general formula (I) and the content of the terminal structure represented by the general formula (II) contained in the polyamide resin (A) 1t is 60 [mol / t] or more and 250 [mol / t] or less,
And the ratio ((I) / () of the content [mol / t] of the terminal structure represented by the general formula (I) and the content [mol / t] of the terminal structure represented by the general formula (II). The long fiber reinforced polyamide resin composition pellets according to any one of claims 3 to 4, wherein II)) is 0.3 to 2.5. The polyamide resin (A) contains a polyamide resin having an amino terminal group and a polyamide resin having a carboxyl terminal group,
The total of amino end group content and carboxyl end group content contained in the polyamide resin (A) 1t is 50 [mol / t] or more and 150 [mol / t] or less,
The ratio (amino terminal group / carboxyl terminal group) of the amino terminal group content [mol / t] to the carboxyl terminal group content [mol / t] is 0.5 to 2.5. The long fiber reinforced polyamide resin composition pellet according to any one of claims 1 to 5. The relative viscosity (ηr) of the polyamide resin (A) at a temperature of 25 ° C in a 98% sulfuric acid solution having a resin concentration of 0.01 g / ml is 1.3 to 3.0. The long fiber reinforced polyamide resin composition pellet according to any one of the above. The long-fiber-reinforced polyamide resin according to any one of claims 1 to 7, wherein the weight average molecular weight Mw of the polyamide resin (A) measured by gel permeation chromatography is 15,000 to 50,000. Composition pellets. 9. The long fiber reinforced polyamide resin according to claim 1, wherein the melt viscosity of the polyamide resin (A) at a melting point of + 60 ° C. and a shear rate of 9728 sec ⁻¹ is 30 Pa · s or less. Composition pellets. The content retention rate of the structure represented by the general formula (I) ((content after residence / content before residence) × 100) before and after residence for 60 minutes under the condition of a melting point + 60 ° C. is 80% or more. The long fiber reinforced polyamide resin composition pellet according to claim 2, wherein the pellet is a long fiber reinforced polyamide resin composition pellet. The weight average molecular weight retention of the polyamide resin (A) before and after residence for 60 minutes under the condition of the melting point + 60 ° C. ((weight average molecular weight after residence / weight average molecular weight before residence) × 100) is 80% to 120%. The long fiber reinforced polyamide resin composition pellet according to any one of claims 1 to 10, wherein the pellet is a long fiber reinforced polyamide resin pellet. The melt viscosity retention rate ((melt viscosity after residence / melt viscosity before residence) × 100) of the polyamide resin (A) before and after residence for 60 minutes under the condition of the melting point + 60 ° C. is 80% to 120%. The long fiber reinforced polyamide resin composition pellet according to any one of claims 1 to 11. 13. The mass reduction rate of the polyamide resin (A) before and after residence for 40 minutes under a condition of a melting point + 60 ° C. in a nitrogen atmosphere is 4% or less, according to claim 1. Long fiber reinforced polyamide resin composition pellets. A thermoplastic polymer (C) having a melt viscosity at 200 ° C. of 0.01 to 20 Pa · s with respect to 100 parts by mass of the polyamide resin (A) is further contained in an amount of 0.1 to 65 parts by mass. 14. The long fiber reinforced polyamide resin composition pellet according to claim 1, wherein the polymer (C) is attached to the reinforcing fiber (B). A molded product comprising the long fiber reinforced polyamide resin composition pellets according to any one of claims 1 to 14, wherein the weight average fiber length of the reinforced fibers in the molded product is in the range of 0.3 mm to 5.0 mm.