KR100419544B1 - Reinforced polyamide resin composition and preparation method thereof - Google Patents

Abstract

It relates to a reinforced polyamide resin composition comprising polyamide and laminated silicates having swelling properties and a process for producing the same, wherein the layered silicates have a whiteness of at least 80 and a methylene blue adsorption capacity of at least 30 meq / 100g.

The reinforced polyamide resin composition is excellent in mechanical strength, heat resistance, dimensional stability and formability and shows low coloration.

Description

Reinforced polyamide resin composition and preparation method thereof

The present invention relates to a reinforced polyamide resin composition comprising polyamide and swellable specific layered silicate and having excellent mechanical strength, heat resistance, dimensional stability and formability, and low coloration, and a process for producing the same.

The polyamide resins according to the invention comprising homogeneously dispersed swellable specific layered silicates or resin compositions containing such polyamide resins have many fields, in particular automotive, electrical and electronic, due to their excellent mechanical properties, heat resistance and dimensional stability. It is expected to be applied to parts used in the field.

Polyamide resins have been used extensively as injection molding materials for producing parts used in automobiles and electric appliances, for example, because polyamide resin moldings have excellent mechanical properties.

In an attempt to improve the toughness and heat distortion temperature of a polyamide resin composition, montmorillonite (JP-A-62-74957, the term "JP-A" as used herein, is referred to as an "unexamined Japanese patent." Circle ") or a composition of a polyamide resin in which a swellable fluoromica-based mineral (JP-A-6-248176) is dispersed or a composition of a resin containing a polyamide resin is known.

However, when producing such a resin composition, there is a problem that the resin composition is colored by increasing the content of swellable montmorillonite or fluoromica-based minerals. Because of this coloring, it is difficult to make the color of the resin composition the same color as the polyamide itself, and there is a limit to dyeing the resin composition.

In addition, using this type of swellable layered silicate can improve physical properties (eg, strength, modulus, heat resistance, etc.), but reduces toughness.

The present invention relates to the solution of the above problems and provides a reinforced polyamide resin composition having high heat resistance, good strength, modulus and toughness and showing a low degree of coloring, and a method for producing the same.

In order to overcome the above problems, the present inventors conducted intensive research. As a result, the inventors have found that polyamide resin compositions comprising polyamide and swellable layered silicates having a whiteness of 80 or more and methylene blue adsorption capacity of 30 meq / 100g or more or a resin composition containing polyamide resin have high heat resistance, excellent strength, and modulus. It has been found that it exhibits toughness and low coloration and the same color as the polyamide itself. In addition, the present inventors have found that the object of the present invention is effectively achieved by using a specific manufacturing method, and completed the present invention.

The gist of the present invention lies in the following.

1. A reinforced polyamide resin composition comprising 100 parts by weight of polyamide and 0.01 to 100 parts by weight of swellable layered silicate having a whiteness of 80 or more and a methylene blue adsorption capacity of 30 meq / 100g or more.

2. A method for producing a reinforced polyamide resin composition comprising polymerizing a monomer to form a polyamide therefrom, wherein 0.01 to 100 parts by weight of a swellable layered silicate having a whiteness of 80 or more and a methylene blue adsorption capacity of 30 meq / 100g or more A process for preparing a reinforced polyamide resin composition present in an amount to form 100 parts by weight of polyamide per monomer.

Polyamide as used in the present invention means a polymer having an amide bond formed by the reaction of amino acids, lactams or diamines with dicarboxylic acids in the main chain. Amino acids are intermediate compounds obtainable by hydrolysis of lactams. Polyamides are also prepared using amino acids as starting materials.

Examples of monomers capable of forming such polyamides are as follows:

As amino acids, 6-amino capronic acid, 11-amino undecanoic acid, 12-amino dodecanoic acid and p-aminomethylbenzoic acid are exemplified.

As the lactam, ε-caprolactam and ω-laurolactam are exemplified.

As the diamine, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 2,4- Dimethyl octamethylenediamine, m-xylylenediamine, p-xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 3,8-bis (aminomethyl) tricyclodecane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane , Bis (aminopropyl) piperazine and aminoethylpiperazine are exemplified.

As dicarboxylic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecane diacid, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, 2-chloroderephthalic acid, 2-methylterephthalic acid, 5-methyl isophthalic acid, 5- Sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexa hydroisophthalic acid and diglycolic acid are exemplified.

Preferred examples of the polyamide used in the present invention are poly caproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 610). ), Polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyundecanamide (nylon 11), polydodecanamide (nylon 12), polytrimethyl hexamethylene terephthalamide ( Nylon TMHT), polyhexaethylene isophthalamide (nylon 61), polyhexamethylene terephthal / isophthalamide (nylon 6T / 6I), polybis (4-aminocyclohexyl) methane dodecamide (nylon PACM 12), poly Bis (3-methyl-4-aminocyclohexyl) methane dodecamide (nylon dimethyl PACM 12), polymethacrylylene adipamide (nylon MXD 6), polyundecamethylene terephthalamide (nylon 11T), Polyundecamethylene hexahydroterephthalamide [nylon 11T (H)], and other copolymerized polyamides and mixed polyamides (mixtures of two or more of these polyamides) obtained from two or more of the above monomers. Of these materials, nylon 6, nylon 46, nylon 66, nylon 11, nylon 12 and the corresponding copolymerized polyamides and mixed polyamides comprising such nylon are particularly preferred.

The polyamides used in the present invention are known melt polymerization methods (JP-A-55-151032), which may optionally be followed by known solid-phase polymerization methods (see, eg, British Patent 798659 (1958)). It can manufacture. The relative viscosity of the polyamides used in the present invention is not particularly limited, but is in the range of 1.5 to 5.0 measured using 96% (weight based on total weight) sulfuric acid as solvent at a temperature of 25 ° C. and a concentration of 1 g / dl. I prefer Relative viscosity of less than 1.5 is not preferable because the mechanical performance of the resin composition is deteriorated in this case. On the other hand, a relative viscosity above 5.0 is undesirable because the moldability of the resin composition deteriorates rapidly in this case.

The whiteness of the swellable layered silicate used in the present invention is required to be 80 or more. When the whiteness is less than 80, the obtained resin composition exhibits strong colorability and excellent resin toughness is not obtained.

In addition, the methylene blue adsorption capacity of the swellable layered silicate used in the present invention is required to be 30 meq / 100 g or more. When the methylene blue adsorption capacity is less than 30 meq / 100 g, decomposition of the swellable layered silicate does not proceed sufficiently, and thus a resin composition having excellent heat resistance, strength and modulus cannot be obtained.

In addition, the preferred viscosity of the swellable layered silicates used in the present invention is 7% by weight (ie, based on the total weight of the dispersion, 7% by weight) in pure water at 25 ° C. and a stirring rate of 6 rpm. Aqueous dispersion containing layered silicates in an amount of%), which is 2,000 cP or more, because a resin composition having excellent physical properties (such as toughness) can be obtained.

In order to further improve the whiteness and methylene blue adsorption capacity of the swellable layered silicates, layered silicates can be added to the pure water and the precipitated non-swellable layered silicates can be removed (ie, water treatment).

The swellable layered silicates used in the present invention have a structure in which a positive charge (ion) is present between negatively filled layers consisting primarily of silicates. Swellable layered silicates have ion exchange capacity. Examples of swellable layered silicates include smectite (e.g. montmorillonite, Weidelite, saponite, hectorite and souconite), vermiculite (e.g. vermiculite), mica (e.g., mica, paragonite, gold mica). , Biotite and scaly mica), szabelite (e.g. margarite, clintonite and anandite), and chlorite (e.g., donvasite, sudite, cucate, clinochlore, chamosite and nimite) It includes. As the swellable layered silicates, not only those present naturally but also those synthesized or modified artificially can be used. Such swellable layered silicates can be treated with organic materials such as onium salts.

Among the swellable layered silicates, swellable fluoromica-based minerals are particularly preferred in view of whiteness, methylene blue adsorption capacity and viscosity as pure dispersion. The swellable fluoromica-based mineral having high whiteness can be easily synthesized, and the methylene blue adsorption capacity and its pure dispersion can be adjusted to its viscosity. Swellable fluoromica-based minerals can be prepared by various methods, for example, by heating a mixture comprising silicide and fluoride (s) or fluoride (s) of talc and sodium and / or lithium or silica, magnesium oxide and fluoride (s). ) Can be obtained by fusion. As a specific example of a method of making this, one may use the one described in JP-A-No. 2-149415, which is incorporated herein by reference. That is, talc is used as a starting material and swellable desired fluoromica-based minerals are obtained by in-situ adding sodium and / or lithium ions to the silicate layer of talc. For this process, a mixture of sodium and / or lithium fluoride (s) and / or fluoride (s) is followed by a short time (at a temperature of about 700 to 1,200 ° C. in air in a magnetic crucible or preferably in a nitrogen atmosphere) Generally 5-6 hours) to obtain the desired fluoromica-based mineral.

In order to obtain swellable fluoromica-based minerals, it is necessary to use sodium or lithium as the metal constituting silicide fluoride (s) or fluoride (s) in alkali metals. These alkali metals can be used alone or in combination. Potassium among alkali metals is not preferably used here because swellable fluoromica-based minerals cannot be obtained using potassium. However, potassium can be used with sodium or lithium in limited amounts (less than 1/3 (weight) of sodium and / or lithium) to control swelling. The content of sodium and / or lithium silicate (s) and / or fluoride (s) mixed with talc is preferably in the range of 10 to 35% by weight, based on the total mixture weight; Amount outside this range reduces the yield of swellable fluoromica-based minerals.

The structure of the swellable fluoromica-based mineral produced by the above method has a structure represented by the following general formula (1).

α (MF) · β (aMgF 2 · bMgO) · γSiO 2 (1)

In the above formula,

M is sodium or lithium,

α, β, γ, a and b represent coefficients of 0.1 ≦ α ≦ 2, 2 ≦ β ≦ 3.5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1 and a + b = 1, respectively. .

As used herein, the term "swellable" means that fluoromica-based minerals absorb polar molecules (such as amino acids, nylon salts or water molecules) or cations between their layers to increase the interlayer distance or further swell the layered silicates or Decomposition means that microparticles are obtained. The fluoromica-based mineral represented by the general formula (1) exhibits this swelling property. The swellable fluoromica-based mineral used in the present invention is preferably 0.1 to 10 m in size and 0.001 to 0.1 m in thickness. When analyzed by the X-ray powder method, the basic spacing of the swellable fluoromica-based minerals used in the present invention is 9 to 20 mm along the C axis.

Swelling can be evaluated by measuring the basic spacing of silicate layers in fluoromica-based minerals by X-ray use. For example, 100 g of fluoromica-based minerals are mixed with 10 L of 0.025N hydrochloric acid aqueous solution at room temperature, and 35 g of aminocaproic acid are added to the mixture, followed by stirring for 10 minutes. In this way protonated aminocaproic acid molecules are added internally to the silicate layer to obtain a swollen fluoromica mineral. The increase in the basic spacing of the silicate layer after this treatment can be considered an index for swelling.

The term "nylon salt" is a generic term referring to salts prepared by reacting an equivalent amount of dicarboxylic acid and diamine. By polycondensation, the nylon salt becomes polyamide. Examples of nylon salts include 6-6 salts, 4-6 salts and 6-10 salts.

In order to obtain a swellable fluoromica-based mineral having a whiteness of 80 or more and a methylene blue adsorption capacity of 30 meq / 100g or more, it is preferable that the talc is first purified so that the whiteness is 80 or more.

In one method for preparing the swellable fluoromica-based minerals used in the present invention, a small amount (less than 20% by weight based on talc) of alumina (Al ₂ O ₃ ; size: 0.01 to 10 μm) is obtained. The swelling property of the swellable fluoromica-based minerals can be controlled.

The swellable layered silicates are used in an amount of from 0.01 to 100 parts by weight, preferably 0.1 to 20 parts by weight, per 100 parts by weight of polyamide or per monomer capable of forming 100 parts by weight of polyamide. It is undesirable that the content of the swellable layered silicate is less than 0.01 parts by weight, since the object of the present invention, i.e., improvement of mechanical strength, heat resistance and dimensional stability cannot be achieved thereby. On the other hand, it is not preferable that its content exceeds 100 parts by weight, because the toughness deteriorates seriously in this case. The amount of monomer needed to form 100 parts by weight of polyamide is determined based on the type of monomer. When lactam is used as the monomer, 100 parts by weight of the monomer forms 100 parts by weight of polyamide. When using amino acids or diamines and dicarboxylic acids as monomers, the amount of monomers is determined taking into account the weight loss due to the polycondensation reaction to form polyamide byproducts by dehydration.

In order to uniformly disperse the swellable layered silicate in the polyamide resin or the resin mixture containing the polyamide resin, it is preferable to polymerize the monomer capable of forming the desired polyamide in the presence of a predetermined amount of the swellable layered silicate. In this case, it is possible to obtain a polyamide resin in which the swellable layered silicate is sufficiently finely dispersed in the polyamide.

If desired, the resin composition of the present invention may also contain additives such as reinforcing fillers, heat stabilizers, light stabilizers, antioxidants, plasticizers, lubricants, colorants, flame retardants. Examples of such additives include glass fibers, carbon fibers, aramid fibers, calcium carbonate, talc, mica, calcium titanate, boron nitride, inorganic silicates, silica gel, hydrotalcite, cristobalite, clay and the like.

If necessary, the resin composition of the present invention may also contain other polymers. Examples of such polymers include polypropylene, ABS resins, polyphenylene oxides, polycarbonates, polyethylene terephthalates, polybutylene terephthalates, polyarylates and various elastomers.

When such other polymer is added to the polyamide resin, the content of the polyamide is preferably 40% by weight or more based on the total weight of the polymer component.

The resin composition of the present invention can be produced in powder, pellets or other shapes. Various useful products such as electrical parts (e.g., connection sockets), automotive parts, etc. can be produced from these by conventional plastic molding methods (e.g. , Extrusion molding, or the like).

Moreover, the fiber using the resin composition of this invention can be manufactured. In this case, the content of the composite layered silicate is generally 0.01 to 20 parts by weight per 100 parts by weight of polyamide or per monomer capable of forming 100 parts by weight of polyamide. The fiber comprising the resin composition of the present invention is characterized by excellent strength and modulus and low heat shrinkage and hydrothermal shrinkage.

The following examples are provided to further illustrate the invention in more detail, but it should not be construed that the invention is thereby limited.

Materials and measurement methods for evaluation used in these and comparative examples are as follows.

Unless otherwise indicated, all parts, percentages, ratios, etc., are by weight.

1. Swellable layered silicate

Fluoromica-based minerals:

Talc was milled in a ball mill to an average particle size of 6.0 μm and then purified to a whiteness of 98. Talc was mixed with silicofluorides having an average particle size of 6.0 μm, as described in Table 1, in an amount of 15% by weight based on the total mixture. The mixture thus obtained was then placed in a magnetic crucible and kept in an electric oven at 800 ° C. for 1 hour to obtain fluoromica minerals (M-1 and M-2).

Fluoromica-based minerals (M-3) were prepared under the same conditions for (M-1), but with talc having a whiteness of 65.

Fluoromica-based mineral (M-4) was prepared under the same conditions for (M-1), but using sodium silicon fluoride in an amount of 8% by weight.

The physical properties of the fluoromica minerals are shown in Table 1.

When the fluoromica-based minerals thus formed were analyzed by X-ray powder method, they did not show peaks allocated at a basic interval of 9.2 ms along the C-axis of talc, but peaked at 12 to 16 ms, which were swellable fluoromica-based minerals. Indicates that it was formed.

Montmorillonite:

Natural montmorillonite (Yamagata prefecture, Japan) was mixed with water and water glass and the mixture was stirred well before the crude particles were removed. This method was repeated five times to obtain montmorillonite (M-5). This unpurified montmorillonite was used as M-6.

Units are by weight.

Footnote: Chemical Composition of Each Composition

Sodium silicate: Na ₂ SiF ₆

Lithium Fluoride: Li ₂ SiF ₆

2. Izod impact test

Performed with notches in accordance with ASTM D-256

3. Bend Test

Performed in accordance with ASTM D-790

4. Heat deformation temperature

Measured according to ASTM D-648

5. Relative Viscosity

Measured at 25 ° C. and a concentration of 1.0 g / dl in 96% sulfuric acid as a solvent

6. Coloring degree of resin composition

It was evaluated according to the yellow index (YI). YI was measured according to JIS K7103.

7. Whiteness

Measurement was made according to JIS 8016. That is, swellable layered silicates sufficiently ground and dried in mortar were stacked on the sample forming tray. The sample was pressed with a glass plate to form a uniform flat plate and used as the sample. Measurement was made using a Hunter whiteness meter equipped with a blue filter (Nendo Handobukku (clay handbook), 2nd edition, p. 562, (1987).

8. Methylene blue (MB) adsorption capacity

See Frank, O. Jones, Jr; API Recommended Practice, Standard Procedure for Testing Drilling Fluids, API RP13B Ninth Edition, May 1982]. That is, a mixture of swellable layered silicate 2% aqueous solution (50 ml), 3% aqueous hydrogen peroxide solution (15 ml) and 5N diluted sulfuric acid (0.5 ml) was gently boiled for 10 minutes in a 250 ml flask. After cooling the solution, several fractions of 0.5 ml of 1 / 100N methylene blue aqueous solution were added successively. After every fraction of the methylene blue solution was added, the flask was stirred thoroughly for 30 seconds, a drop of sample was taken from the flask using a glass rod and then dropped onto the filter paper, where a light blue ring was observed around the dark blue spots. If a bright blue ring was observed, the flask was stirred for 2 more minutes. The addition of methylene blue solution continued until the blue ring disappeared even after stirring for 2 minutes. Methylene blue adsorption capacity is calculated from the following equation.

9. Viscosity of Swellable Layered Silicate Dispersions in Pure Water

A 7% (by weight) dispersion of swellable layered silicate in pure water was prepared in a flask. The viscosity of the dispersion was measured with a type B viscometer equipped with a No. 5 rotor under conditions of 6 rpm and 25 ° C.

Examples 1-6

10 kg of ε-caprolactam was mixed with 500 g of water and M-1 or M-2 in the amounts as listed in Table 2. The mixture thus obtained was fed into a 30 L reaction tank and polymerized ε-caprolactam to obtain a reinforced nylon 6 resin composition. The polymerization reaction was carried out according to the following method. Under a nitrogen atmosphere, the mixture was heated to 250 ° C. and the steam was slowly evacuated with stirring for 1 hour under elevated pressure from 4 kg / cm ² to 15 kg / cm ² . After maintaining this pressure for 2 hours, the pressure was reduced to atmospheric pressure and the mixture was polymerized with stirring at 30 rpm for 1 hour at 260 ° C. Upon completion of the polymerization, the reinforced nylon 6 resin composition was taken from the reaction tank and then cut into pellets. The pellet (size: 3 mm) of the thus-reinforced nylon 6 resin composition was washed with hot water at 95 ° C. for 5 hours to purify the composition, and the pellet was dried under vacuum at 100 ° C. for 8 hours.

Molding of test specimens from the pellets was carried out using an injection molding machine with an injection time of 6 seconds and a cooling time of 6 seconds at a cylinder temperature of 250 ° C. to obtain test specimens 1/8 inch thick and to test their physical properties. The results are shown in Table 2. A resin composition excellent in strength, modulus and heat resistance and also having a low YI value was obtained.

Comparative Example 1

The experiment was performed in the same manner as in Example 1 except that M-1 and M-2 were not used. The results are shown in Table 3. The obtained resin composition did not have sufficient strength, modulus and heat resistance.

Comparative Examples 2 to 4

The experiment was performed in the same manner as in Example 1 except that M-3 was used instead of M-1 and M-2. The results are shown in Table 3. The obtained resin composition did not have sufficient strength, modulus and heat resistance. In addition, the YI value was high.

Comparative Examples 5 to 7

The experiment was performed in the same manner as in Example 1 except that M-4 was used instead of M-1 and M-2. The results are shown in Table 4. The obtained resin composition did not have sufficient strength, modulus and heat resistance. In addition, the YI value was high.

Examples 7-9

The experiment was performed in the same manner as in Example 1 except that montmorillonite (M-5) was used instead of fluoromica (M-1 and M-2). The results are shown in Table 5. A resin composition excellent in strength, modulus and heat resistance and having a low YI value was obtained.

Comparative Examples 8 to 10

The experiment was performed in the same manner as in Example 1 except that montmorillonite (M-6) was used instead of fluoromica (M-1 and M-2). The results are shown in Table 5. The obtained resin composition did not have sufficient strength, modulus and heat resistance. Moreover, the YI value was high.

Examples 10-15

10 kg of ω-laurolactam were mixed with 1.5 kg of water and M-1 or M-2 in amounts as described in Table 6, respectively. The mixture thus obtained was fed into a 30 L reaction tank and polymerized ω-laurolactam to obtain a reinforced nylon 12 resin composition. The polymerization reaction was carried out according to the following method. Under a nitrogen atmosphere, the mixture was heated to 240 ° C. and stirred for 1 hour under elevated pressure from 4 kg / cm ² to 20 kg / cm ² and the steam was slowly evacuated. After maintaining this pressure for 2 hours, the pressure was reduced to atmospheric pressure and the mixture was polymerized with stirring at 250 ° C. for 1 hour at 30 rpm. Upon completion of the polymerization, the reinforced nylon 12 resin composition was taken from the reaction tank and then cut into pellets. The pellet was dried under vacuum at 100 ° C. for 8 hours.

Molding of test specimens from pellets was carried out using an injection molding machine with an injection time of 6 seconds and a cooling time of 6 seconds at a cylinder temperature of 240 ° C. to obtain test specimens 1/8 inch thick and to test their physical properties. The results are shown in Table 6. A resin composition excellent in strength, modulus and heat resistance and also having a low YI value was obtained.

Comparative Example 11

The experiment was conducted in the same manner as in Example 10 except that M-1 and M-2 were not used. The results are shown in Table 7. The obtained resin composition did not have sufficient strength, modulus and heat resistance.

Comparative Examples 12 to 14

The experiment was performed in the same manner as in Example 10 except that M-3 was used instead of M-1 and M-2. The results are shown in Table 7. The obtained resin composition did not have sufficient strength, modulus and heat resistance. In addition, the YI value was high.

Comparative Examples 15 to 17

The experiment was performed in the same manner as in Example 10 except that M-4 was used instead of M-1 and M-2. The results are shown in Table 8. The obtained resin composition did not have sufficient strength, modulus and heat resistance. In addition, the YI value was high.

Examples 16-18

The experiment was carried out in the same manner as in Example 10 except that montmorillonite (M-5) was used instead of fluoromica (M-1 and M-2). The results are shown in Table 9. A resin composition excellent in strength, modulus and heat resistance and having a low YI value is obtained.

Comparative Examples 18-20

The experiment was performed in the same manner as in Example 10 except that montmorillonite (M-6) was used instead of fluoromica (M-1 and M-2). The results are shown in Table 9. The obtained resin composition did not have sufficient strength, modulus and heat resistance.

In addition, the YI value was high.

Examples 19 to 24

10 kg of nylon 66 salt was mixed with 3.0 kg of water and M-1 or M-2 in amounts as described in Table 10, respectively. The mixture thus obtained was fed into a 30 L reaction tank and polymerized nylon 66 salt to obtain a reinforced nylon 66 resin composition. The polymerization reaction was carried out according to the following method. Under a nitrogen atmosphere, the mixture was heated to 280 ° C. and the steam was slowly evacuated with stirring for 60 minutes under elevated pressure from 4 kg / cm ² to 18 kg / cm ² . After maintaining this pressure for 2 hours, the pressure was reduced to atmospheric pressure and the mixture was polymerized with stirring at 30 rpm for 1 hour at 280 ° C. Upon completion of the polymerization, the reinforced nylon 66 resin composition was taken from the reaction tank and then cut into pellets. The pellet was dried under vacuum at 100 ° C. for 8 hours.

Molding of test specimens from the pellets was carried out using an injection molding machine with an injection time of 6 seconds and a cooling time of 6 seconds at a cylinder temperature of 290 ° C. to obtain test specimens 1/8 inch thick and to test their physical properties. A resin composition excellent in strength, modulus and heat resistance and also having a low YI value was obtained.

Comparative Example 21

The experiment was conducted in the same manner as in Example 19 except that M-1 and M-2 were not used. The results are shown in Table 11. The obtained resin composition did not have sufficient strength, modulus and heat resistance.

Comparative Examples 22 to 24

The experiment was performed in the same manner as in Example 19 except that M-3 was used instead of M-1 and M-2. The results are shown in Table 11. The resin composition strength, modulus and heat resistance obtained were not sufficient. In addition, the YI value was high.

Comparative Examples 25 to 27

The experiment was conducted in the same manner as in Example 19 except that M-4 was used instead of M-1 and M-2. The results are shown in Table 12. The obtained resin composition did not have sufficient strength, modulus and heat resistance. In addition, the YI value was high.

Examples 25-27

The experiment was performed in the same manner as in Example 19 except that montmorillonite (M-5) was used instead of fluoromica (M-1 and M-2). The results are shown in Table 13. A resin composition excellent in strength, modulus and heat resistance and having a low YI value was obtained.

Comparative Examples 28 to 30

The experiment was carried out in the same manner as in Example 19 except that montmorillonite (M-6) was used instead of fluoromica (M-1 and M-2). The results are shown in Table 13. The obtained resin composition did not have sufficient strength, modulus and heat resistance. In addition, the YI value was high.

According to the present invention, a reinforced polyamide resin composition which is excellent in mechanical strength, heat resistance, dimensional stability and formability and low in coloration can be obtained.

While the invention has been described in detail with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention.

Claims (5)

A reinforced polyamide resin composition comprising 100 parts by weight of polyamide and 0.01 to 100 parts by weight of swellable fluoromica-based mineral having a whiteness of 80 or more and a methylene blue adsorption capacity of 30 meq / 100g or more. The reinforced polyamide resin composition according to claim 1, wherein the viscosity of the swellable fluoromica-based mineral is at least 2,000 cP as measured by a 7% (weight) dispersion in pure water at 25 ° C. and a stirring rate of 6 rpm. The reinforced polyamide resin composition according to claim 1, wherein the swellable fluoromica-based mineral is used in an amount of 0.1 to 20 parts by weight per 100 parts by weight of polyamide. A method for preparing a reinforced polyamide resin composition comprising polymerizing a monomer to form a polyamide therefrom, wherein the swellable fluoromica-based mineral has a whiteness of 80 or more and a methylene blue adsorption capacity of 30 meq / 100g or more. A process for preparing a reinforced polyamide resin composition present in an amount that forms 100 parts by weight of polyamide per additional monomer. The method for producing a reinforced polyamide resin composition according to claim 4, wherein the swellable fluoromica-based mineral is used in an amount of 0.1 to 20 parts by weight per 100 parts by weight of polyamide.