JP2010126646A - Thermoplastic resin composition for laser welding and composite molding product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition for laser welding, having good mechanical strength and excellent laser welding property and being friendly to the environment. <P>SOLUTION: The thermoplastic resin composition for laser welding is produced by compounding (A) 100 pts.wt. of a resin component comprising a thermoplastic resin (a) and an aliphatic polyester copolymer (b) with (B) 0-100 pts.wt. of a reinforcing filler, wherein the aliphatic polyester copolymer (b) comprises 0-20 mol% of an aliphatic oxycarboxylic acid unit, 40-50 mol% of an aliphatic or alicyclic diol unit and 40-50 mol% of an aliphatic dicarboxylic acid unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition for laser welding. Specifically, it is excellent in laser light transmission and has a large adhesive strength by laser welding. Further, it is a thermoplastic resin composition that is environmentally friendly at the time of disposal of the molded product, a composite molded product welded by a laser welding method, and The present invention relates to a method for manufacturing a composite molded article.

  In recent years, plastic parts that can be reduced in weight have been used for mechanical parts and structural parts in the fields of automobiles and electronic / electrical equipment in place of metal. As a resin used for these parts, a thermoplastic resin has been widely used in view of easy recycling of defective products. Among these thermoplastic resins, engineering plastics such as aromatic polyester resin, polyamide resin, polycarbonate resin, polyacetal resin, and polyphenylene ether resin are mechanical properties, electrical properties, heat resistance, dimensional stability, and other physical and Due to its excellent chemical properties, it is widely used in automotive parts, electrical / electronic equipment parts, precision equipment parts, and so on.

Recently, among the various applications described above, engineering plastics are also used for precision products that seal electrical circuit parts, such as automotive electrical parts (control units, etc.), various sensor parts, connector parts, etc. Has been deployed. As a method for sealing such components, bonding with an adhesive, ultrasonic welding, hot plate welding, laser welding, and the like are performed. However, the construction method using adhesive has a problem of environmental load such as surrounding contamination in addition to time loss until curing, and ultrasonic welding, hot plate welding, etc. may cause damage to the product due to vibration and heat, Problems such as the need for post-treatment due to the generation of wear powder and burrs have been pointed out.
On the other hand, laser welding is advantageous in that it is non-contact, does not generate wear powder and burrs, and has little damage to the product. However, the thermoplastic resin generally has a low laser beam transmittance, and thus has a problem that the thickness design of the product is restricted. If the laser output is increased in order to weld a thick member, there may be a problem such as melting on the laser incident side surface, smoke generation, and bubbles due to abnormal heat generation at the bonding interface. Further, the transmittance is also reduced by foreign matter or haze caused by a deteriorated product of the resin by laser light.

  In addition, when used as a structural material, high rigidity is required. Therefore, it is possible to improve the rigidity by adding a filler such as glass fiber. There was a problem that the rate decreased.

  In order to solve the above problems, for example, there is a method of using a polybutylene terephthalate copolymer to widen the welding condition width by controlling the melting point (Patent Document 1). With this method alone, the improvement in transmittance is small, and the limitation of the thickness design of the product cannot be solved. Moreover, the method of mix | blending an amorphous resin and an elastomer with a polybutylene terephthalate-type resin is disclosed (patent documents 2 and 3). Although this method may improve the transmittance, there is a problem that the transmittance is likely to vary depending on the blending and molding conditions.

  On the other hand, as the use of resin expands and is used in large quantities, from the viewpoint of environmental conservation on a global scale in recent years, the ease of volume reduction and fine granulation at the time of disposal of molded products, biodegradability by microorganisms, etc. Performance is also demanded. From this point of view, attempts have been made to promote volume reduction and fine granulation at the time of disposal of molded articles by using biodegradable polymers that can be decomposed by microorganisms.

As such biodegradable polymers, aliphatic polyesters such as polylactic acid have attracted attention. However, aliphatic polyesters generally have the disadvantages of poor mechanical properties and low melting points. In order to compensate for such drawbacks, attempts have been made to develop resin materials with improved biodegradability and mechanical properties by blending biodegradable polymers with other resins. However, since homopolyethylene terephthalate resin (PET resin) and homopolybutylene terephthalate resin (PBT resin), which are widely used as aromatic polyester resins, generally have low compatibility with polylactic acid, they are substantially blended with polylactic acid. Is impossible. From the viewpoint that it is important to introduce an aliphatic group into the main chain or side chain of the aromatic polyester resin in order to improve such compatibility deficiency between the aromatic polyester and polylactic acid, for example, poly Blend of lactic acid and aromatic polyester copolymer having 6 or more carbon atoms in diol component or aromatic polyester copolymer having diol component and / or dicarboxylic acid component having 6 or more carbon atoms copolymerized A polyester resin composition has been proposed (Patent Document 4).
However, since such an aromatic polyester copolymer has a low crystallization rate, when the blending amount is large, there remains a problem that the moldability is extremely poor as an injection molding resin. In this patent document, examples of injection molding are shown in Example 12 and Comparative Example 11, but only the effect of improving heat resistance is shown. Application to film.

  Moreover, the resin composition which mix | blended the aliphatic polyester copolymer with aromatic polyester resins, such as PBT resin (patent document 5), or aromatic polycarbonate resin (patent document 6) is disclosed. However, there is no suggestion about laser weldability in these.

Japanese Patent No. 3510817 Japanese Patent Laid-Open No. 2003-292752 JP 2004-315805 A JP 2003-171536 A JP 2007-9053 A JP 2007-211109 A

  The present invention has been made in view of the above circumstances, and the purpose thereof is a thermoplastic resin composition having good mechanical strength, excellent laser welding characteristics, and environmental protection, and is welded by a laser welding method. Another object of the present invention is to provide a composite molded product and a method for producing the composite molded product.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have improved the transmittance and mechanical strength of a resin molded product by incorporating a specific aliphatic polyester into a thermoplastic resin. It was found that a thermoplastic resin molded article having excellent welding characteristics was obtained, and as a result, a composite molded article strongly bonded by laser welding was obtained, and the present invention was completed.

The first gist of the present invention is as follows.
A resin composition comprising 0 to 100 parts by weight of a reinforcing filler (B) with respect to 100 parts by weight of a resin component (A) composed of a thermoplastic resin (a) and an aliphatic polyester copolymer (b). The aliphatic polyester copolymer (b) is an aliphatic oxycarboxylic acid unit represented by the following formula (I): 0 to 20 mol% of an aliphatic oxycarboxylic acid unit represented by the following formula (II) A thermoplastic resin composition for laser welding comprising 40 to 50 mol% of a formula diol unit and 40 to 50 mol% of an aliphatic dicarboxylic acid unit represented by the following formula (III).

（式中、Ｒ^１は２価の脂肪族炭化水素基を示し、Ｒ^２は２価の脂肪族炭化水素基又は２価の脂環式炭化水素基を示し、Ｒ^３は直接結合又は２価の脂肪族炭化水素基を示す。）

(Wherein R ¹ represents a divalent aliphatic hydrocarbon group, R ² represents a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group, and R ³ represents a direct bond or a divalent group. Represents an aliphatic hydrocarbon group.)

The second gist of the present invention is as follows:
A composite in which the first member made of the thermoplastic resin composition for laser welding and the second member made of the thermoplastic resin composition are brought into close contact with each other, and laser light is irradiated from the first member side for welding. Exists in molded products.

The third gist of the present invention is as follows:
Including a step of bringing the first member made of the thermoplastic resin composition for laser welding into close contact with the second member made of the thermoplastic resin composition and irradiating the first member side with laser light for welding. It exists in the manufacturing method of a composite molded product.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a thermoplastic resin composition having good mechanical strength, excellent laser welding characteristics such as laser transmission properties, and environmental considerations, and a composite molded product welded by a laser welding method. Became. Such molded products are widely used industrially, and their utility value is extremely high.

Thermoplastic resin (a):
The thermoplastic resin (a) used in the present invention is not particularly limited as long as it can be thermoformed, and is a known thermoplastic resin other than the aliphatic polyester copolymer (b) described later. For example, aromatic polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polyamide 4, polyamide 6, polyamide 7, polyamide 8, polyamide 11, polyamide 12, polyamide 66, polyamide 69, polyamide 610, polyamide 611, polyamide 612, Aliphatic and aromatic polyamide homopolymers such as polyamide 6T, aliphatics such as polyamide 6/66 copolymer, polyamide 6/12 copolymer, polyamide 6 / 6T copolymer, polyamide 6I / 6T copolymer and the like Polyolefins such as aromatic polyamide copolymers, semi-aromatic polyamide resins obtained by polycondensation reaction of xylylenediamine and aliphatic dicarboxylic acids such as polymetaxylylene adipamide (polyamide MXD6), polyethylene and polypropylene Resin, polystyrene, styrene-acrylonitrile copolymer (AS resin), styrene- (meth) acrylic acid copolymer, styrene-methyl methacrylate copolymer, rubber-modified polystyrene (HIPS), acrylonitrile-butadiene-styrene copolymer Polystyrene resins such as coalescence (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), polycarbonate resin, polyacetal resin, polyphenylene ether resin, polyphenylene sulfide resin, liquid crystal polymer, polysulfone resin, polymethyl acrylate Resins etc. are mentioned, and these can be used in combination of two or more. Among these, general-purpose resins such as polyolefin resins and polystyrene resins are preferable in terms of low molding processing temperature, and aromatic polyester resins, polycarbonate resins, polyamide resins, and polyacetal resins are preferable in terms of high mechanical strength and rigidity. So-called engineering plastics such as polyphenylene ether resin are preferred. Among such engineering plastics, polycarbonate resins and aromatic polyester resins are more preferable from the viewpoint of heat resistance and compatibility with aliphatic polyester copolymers.

Aromatic polyester resin:
The aromatic polyester resin is a polyester resin containing an aromatic ring in any of its constituent components, dicarboxylic acid or a derivative thereof, diol, and other constituent components used as necessary. As aromatic polyester resin, a well-known thing can be used widely and you may use 2 or more types together.

  As the dicarboxylic acid or derivative thereof, aromatic dicarboxylic acid, alicyclic dicarboxylic acid, and aliphatic dicarboxylic acid, and esters of these lower alkyls or glycols are preferred, and aromatic dicarboxylic acids or their lower alkyls (for example, C1-4) or an ester of glycol is more preferable, and terephthalic acid or a lower alkyl ester thereof is more preferable. Two or more of these dicarboxylic acids or derivatives thereof may be used in combination.

Aromatic dicarboxylic acids include terephthalic acid, phthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-benzophenone dicarboxylic acid, 4,4′-diphenoxy. Preferred examples include ethanedicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid.
Preferred examples of the alicyclic dicarboxylic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.
Preferred examples of the aliphatic dicarboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.

As the diol, an aliphatic diol, an alicyclic diol, and an aromatic diol are preferable, and two or more of these may be used in combination.
The aliphatic diol is preferably an aliphatic diol having 2 to 20 carbon atoms. For example, ethylene glycol, 1,4-butanediol, diethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3- Preferred examples include propanediol, polypropylene glycol, polytetramethylene glycol, dibutylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol and 1,8-octanediol.
The alicyclic diol is preferably an alicyclic diol having 2 to 20 carbon atoms, such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol, and 1, 4-cyclohexanedimethylol can be mentioned as a preferred example.
The aromatic diol is preferably an aromatic diol having 6 to 14 carbon atoms, such as xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane and bis. (4-Hydroxyphenyl) sulfone can be mentioned as a preferred example.

The aromatic polyester resin may have a hydroxycarboxylic acid, a monofunctional component, and / or a trifunctional or higher polyfunctional component in addition to the above components.
Preferred examples of the hydroxycarboxylic acid include lactic acid, glycolic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 6-hydroxy-2-naphthalenecarboxylic acid and p-β-hydroxyethoxybenzoic acid.
Preferred examples of the monofunctional component include alkoxycarboxylic acid, stearyl alcohol, benzyl alcohol, stearic acid, benzoic acid, t-butylbenzoic acid and benzoylbenzoic acid.
Preferred examples of the trifunctional or higher polyfunctional component include tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol, and pentaerythritol.

  The aromatic polyester resin preferably contains a polybutylene terephthalate resin (PBT resin), more preferably polybutylene terephthalate having terephthalic acid as the only dicarboxylic acid unit and 1,4-butanediol as the only diol unit. More preferably, it contains a homopolymer. The PBT resin referred to in the present invention means that terephthalic acid accounts for 50 mol% or more of all dicarboxylic acid components, and 1,4-butanediol accounts for 50 mol% or more of all diols. The PBT resin further preferably has a terephthalic acid ratio in the dicarboxylic acid unit of 70 mol% or more, more preferably 90 mol% or more. Moreover, 70 mol% or more is preferable and the ratio of 1, 4- butanediol in a diol unit has more preferable 90 mol% or more. Use of such a PBT resin is preferred because mechanical properties and heat resistance tend to be further improved.

  As the PBT resin, the intrinsic viscosity measured in a 1: 1 (weight ratio) mixture of phenol and tetrachloroethane at 30 ° C. is 0.3 to 3 dl / g, and further 0.3 to 1.5 dl / g, In particular, a PBT resin of 0.5 to 1.3 dl / g is preferable. If the intrinsic viscosity of the PBT resin is less than 0.3 dl / g, the mechanical performance of the resulting resin composition may be reduced. If the intrinsic viscosity is 1.5 dl / g or more, the flow of the resin composition The moldability may be lowered and the moldability may be deteriorated. Furthermore, the dispersibility of the aliphatic polyester copolymer tends to decrease. As the PBT resin, two or more kinds of PBT resins having different intrinsic viscosities may be used in combination to obtain an intrinsic viscosity within the above range.

When manufacturing an aromatic polyester resin, a well-known method can be employ | adopted widely. For example, in the case of a PBT resin composed of a terephthalic acid component and a 1,4-butanediol component, either a direct polymerization method or a transesterification method can be employed. The direct polymerization method is, for example, a method in which terephthalic acid and 1,4-butanediol are directly esterified, and water is generated in the initial esterification reaction. The transesterification method is a method using, for example, dimethyl terephthalate as a main raw material, and alcohol is generated by an initial transesterification reaction. The direct esterification reaction is preferable from the viewpoint of raw material costs.
Moreover, you may manufacture an aromatic polyester resin by any method of a batch method and a continuous method about the raw material supply or the discharge form of a polymer. Furthermore, the initial esterification reaction or transesterification reaction is performed in a continuous operation, and the subsequent polycondensation is performed in a batch operation, or conversely, the initial esterification reaction or transesterification reaction is performed in a batch operation, followed by There is also a method of performing polycondensation in a continuous operation.

  Further, as the thermoplastic resin (a) used in the present invention, when an aromatic polyester resin and another thermoplastic resin are used in combination, the laser permeability, durability, moldability, low water absorption, and impact strength are excellent. In view of the above, it is preferable to use another thermoplastic resin selected from polystyrene resins, polycarbonate resins, and alloys of these resins. When the aromatic polyester resin is used in combination with another thermoplastic resin, 50% by weight or more in the thermoplastic resin (a) is preferably an aromatic polyester resin, and more preferably 60% by weight or more. From the viewpoint of moldability, the aromatic polyester resin is particularly preferably a polybutylene terephthalate resin.

Polycarbonate resin:
As the polycarbonate resin, either an aromatic polycarbonate resin or an aliphatic polycarbonate resin can be used, but an aromatic polycarbonate resin is preferred.
The aromatic polycarbonate resin is obtained by reacting an aromatic dihydroxy compound or a small amount thereof with a phosgene or a carbonic acid diester. The production method of the aromatic polycarbonate resin is not particularly limited, and can be produced by a conventionally known phosgene method (interfacial polymerization method) or a melting method (transesterification method). Moreover, when using the aromatic polycarbonate resin obtained by a melting method, you may adjust and use the amount of OH groups of a terminal group.

  As aromatic dihydroxy compounds, 2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4, 4-dihydroxydiphenyl and the like can be mentioned, and bisphenol A is preferable. Two or more of these aromatic dihydroxy compounds may be used in combination. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

  In order to obtain a branched aromatic polycarbonate resin, a part of the above-mentioned aromatic dihydroxy compound is mixed with a branching agent such as phloroglucin, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene- 2,4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3, 1,3 Polyhydroxy compounds such as 5-tri (4-hydroxyphenyl) benzene and 1,1,1-tri (4-hydroxyphenyl) ethane, and 3,3-bis (4-hydroxyaryl) oxindole (ie, isatin) Bisphenol), 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like may be substituted. The amount of the compound to be substituted is usually 0.01 to 10 mol%, preferably 0.1 to 2 mol%, based on the aromatic dihydroxy compound.

  The aromatic polycarbonate resin is preferably a polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and another aromatic dihydroxy compound. And a polycarbonate copolymer derived from the above. Further, it may be a copolymer mainly composed of a polycarbonate resin, such as a copolymer with a polymer or oligomer having a siloxane structure. Furthermore, you may mix and use 2 or more types of the aromatic polycarbonate resin mentioned above.

  The molecular weight of the polycarbonate resin is 10,000 to 30,000, preferably 15,000 to 25,000 in terms of viscosity average molecular weight converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. . When the viscosity average molecular weight is less than 13,000, the impact resistance tends to decrease, and when it exceeds 30,000, the fluidity tends to decrease.

Polyamide resin:
The polyamide resin used in the present invention is not particularly limited as long as it is a known polyamide resin, that is, a polymer containing an amide bond (—NHCO—) in the main chain and capable of being heated and melted. Specifically, various types of polyamide resins such as polycondensates of lactam, polycondensates of salts of diamine and dicarboxylic acid, polycondensates of ω-aminocarboxylic acid, or copolymerized polyamide resins and blends thereof It is a thing.

Examples of the lactam include ε-caprolactam and ω-laurolactam.
Examples of the diamine include tetramethylene diamine, hexamethylene diamine, 2-methylpentamethylene diamine, undecamethylene diamine, dodecamethylene diamine, (2,2,4- or 2,4,4-) trimethylhexamethylene diamine, 5- Methylnonamethylenediamine, metaxylylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5 5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine Aliphatic, alicyclic, etc. Aromatic diamine and the like.

Examples of dicarboxylic acids include adipic acid, speric acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid. Aliphatic, alicyclic and aromatic dicarboxylic acids such as acid, hexahydroterephthalic acid, hexahydroisophthalic acid and the like can be mentioned.
Examples of the ω-aminocarboxylic acid include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid.
In the present invention, homopolymers or copolymers derived from these raw materials can be used alone or in the form of a mixture.
These lactams, dicarboxylic acids and diamines which are polyamide resin polymerization monomers preferably have 4 or more and 15 or less carbon atoms. When the number of carbon atoms is more than 15, generally, the rigidity tends to be low, and when it is less than 4, the hygroscopicity tends to increase, and the withstand voltage may be lowered.

The salt which is a structural unit of the polyamide resin can be obtained by neutralizing the above diamine and dicarboxylic acid in an aqueous solution at high temperature under pressure. The salt thus obtained, the above lactam, and ω-aminocarboxylic acid are condensed under pressure and high temperature to advance the oligomerization reaction, and then the polymerization proceeds under reduced pressure, which is used in the present invention. A polyamide resin can be produced.
As the polyamide resin, polyamide 6, polyamide 66 and polyamide MXD6 are preferable from the viewpoint of availability and heat resistance.

Moreover, as a polyamide resin, what has a specific apparent melt viscosity is preferable. A preferable apparent melt viscosity is a value measured using a capillary rheometer (“Capillograph 1C” manufactured by Toyo Seiki Co., Ltd.) with a capillary L / D of 30 mm / 1 mm, a temperature of 280 ° C., and a shear rate of 100 sec ⁻¹ . It is -10000 poise, More preferably, it is 800-8000, More preferably, it is 850-7000 poise. When the apparent melt viscosity is lower than 750 poise, the mechanical strength may be lowered, and when it is higher than 10,000 poise, the fluidity is lowered and the productivity tends to be lowered.

Polyacetal resin:
The polyacetal resin is a polymer produced by polymerization of formaldehyde or trioxane, and examples thereof include a homopolymer having an oxymethylene group as a repeating unit. In order to increase heat resistance and chemical resistance, it is common practice to convert terminal groups to ester groups or ether groups.
The polyacetal resin may be a block copolymer. This type of copolymer is composed of a homopolymer block having the oxymethylene group as a repeating unit and another type of polymer block. Specific examples of other types of polymer blocks include, for example, polyalkylene glycol, polythiol, vinyl acetate, acrylic acid copolymer, hydrogenated butadiene, acrylonitrile copolymer, and the like.
The polyacetal resin may be a random copolymer. In this type of copolymer, formaldehyde and trioxane are copolymerized with other aldehydes, cyclic ethers, vinyl compounds, ketene, cyclic carbonates, epoxides, isocyanates, ethers, and the like. Specific examples of the compound to be copolymerized include ethylene oxide, 1,3-dioxolane, 1,3-dioxane, 1,3-dioxepene, epichlorohydrin, propylene oxide, isobutylene oxide and styrene oxide. In this type of copolymer, the polymerization catalyst is generally deactivated and the terminal is stabilized after cationic polymerization. A copolymer containing an oxymethylene group as a main repeating unit and containing an oxyalkylene group having 2 or more carbon atoms is generally used.

Polyphenylene ether resin:
The polyphenylene ether resin is a homopolymer or copolymer having a structural unit represented by the following formula (IV).

（式中、２つのＲ^４は、それぞれ独立して、水素原子、ハロゲン原子、第１級もしくは第２級アルキル基、アリール基、アミノアルキル基、炭化水素オキシ基又はハロ炭化水素オキシ基を表し、２つのＲ^５は、それぞれ独立して、水素原子、ハロゲン原子、第１級もしくは第２級アルキル基、アリール基、ハロアルキル基、炭化水素オキシ基又はハロ炭化水素オキシ基を表す。ただし、２つのＲ^４が共に水素原子になることはない。）

(In the formula, two R ^{4 s} each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, an aminoalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group. Two R ^{5 s} each independently represent a hydrogen atom, a halogen atom, a primary or secondary alkyl group, an aryl group, a haloalkyl group, a hydrocarbonoxy group, or a halohydrocarbonoxy group, provided that 2 Two R ⁴ cannot be a hydrogen atom.)

R ⁴ and R ⁵ are preferably a hydrogen atom, a primary or secondary alkyl group, or an aryl group. Preferable examples of the primary alkyl group include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-amyl group, isoamyl group, 2-methylbutyl group, n-hexyl group, 2, A 3-dimethylbutyl group, a 2,3- or 4-methylpentyl group, a heptyl group, etc. are mentioned. Preferable examples of the secondary alkyl group include isopropyl group, sec-butyl group, 1-ethylpropyl group and the like. Preferable examples of the aryl group include a phenyl group and a naphthyl group. In particular, R ⁴ is more preferably a primary or secondary alkyl group having 1 to 4 carbon atoms or a phenyl group. R ⁵ is more preferably a hydrogen atom.

  Specific examples of the polyphenylene ether include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6- Dipropyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether Tell. Examples of the copolymer include various 2,6-dialkylphenol / 2,3,6-trialkylphenol copolymers. Among these, poly (2,6-dimethyl-1,4-phenylene) ether is particularly preferable.

  The polyphenylene ether resin preferably has an intrinsic viscosity of 0.2 to 0.8 dl / g measured in chloroform at a temperature of 30 ° C., more preferably 0.2 to 0.7 dl / g, A range of 0.6 dl / g is particularly preferable. If the intrinsic viscosity is less than 0.2 dl / g, the impact resistance of the resin composition may be insufficient, and if it exceeds 0.6 dl / g, moldability and appearance tend to be deteriorated.

  The polyphenylene ether resin is preferably modified by means of alloying with a polystyrene resin or a polyamide resin in order to improve the fluidity of the polyphenylene ether resin. As the polystyrene-based resin or polyamide resin used for modification, those listed above are used. For example, 10 to 70% by weight of polyphenylene ether resin can be blended and modified.

Aliphatic polyester copolymer (b):
The aliphatic polyester copolymer is an aliphatic oxycarboxylic acid unit represented by the following formula (I): 0 to 20 mol%, an aliphatic or alicyclic diol unit represented by the following formula (II): 40 to 50 mol % And an aliphatic dicarboxylic acid unit of 40 to 50 mol% represented by the following formula (III): an aliphatic oxycarboxylic acid, an alicyclic diol and an aliphatic dicarboxylic acid corresponding to each unit. It can be produced by copolymerizing a predetermined amount.

（式中、Ｒ^１は２価の脂肪族炭化水素基を示し、Ｒ^２は２価の脂肪族炭化水素基又は２価の脂環式炭化水素基を示し、Ｒ^３は直接結合又は２価の脂肪族炭化水素基を示す。）

(Wherein R ¹ represents a divalent aliphatic hydrocarbon group, R ² represents a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group, and R ³ represents a direct bond or a divalent group. Represents an aliphatic hydrocarbon group.)

The aliphatic oxycarboxylic acid unit of the above formula (I) has one hydroxyl group and carboxyl group in the molecule represented by HO—R ¹ —COOH (R ¹ represents a divalent aliphatic hydrocarbon group). It can be obtained by using an aliphatic oxycarboxylic acid or derivative thereof (cyclic monomer, cyclic dimer, anhydride, ester, etc.). The aliphatic oxycarboxylic acid is preferably an α-oxycarboxylic acid represented by the following formula (II). In the following formula (II), n is preferably 0 or an integer of 1 to 5.

（式中、ｎは０又は１〜１０の整数である。）

(In the formula, n is 0 or an integer of 1 to 10.)

  Specific examples of the aliphatic oxycarboxylic acid represented by the formula (II) include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2 -Hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid and the like can be mentioned, and these can be used in combination of two or more. When these aliphatic oxycarboxylic acids have optical isomers, they may be any of D-form, L-form and racemate. Among these, lactic acid or glycolic acid is preferable, and lactic acid is particularly preferable. Lactic acid is particularly prominent in increasing the polymerization rate during the production of the polyester copolymer, and is easily available. Lactic acid is usually available in the form of a 30-95% by weight aqueous solution.

The aliphatic or alicyclic diol corresponding to the aliphatic diol unit of the formula (II) is represented by HO—R ² —OH (R ² represents a divalent aliphatic or alicyclic hydrocarbon). Diol. In the formula, the divalent aliphatic hydrocarbon group represented by R ² is preferably a linear alkylene group, and the number of carbon atoms is usually 2 to 10, preferably 3 to 10, and more preferably 4 to 4. 6. Examples of the alicyclic hydrocarbon group represented by R ^2, preferably a cycloalkylene group, the number of carbon atoms is usually 3-10, preferably 4-6.

  Specific examples of the diol as described above include ethylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4- Examples thereof include cyclohexanedimethanol, and these can be used as a mixture of two or more. Among the above diols, 1,4-butanediol is particularly preferable from the viewpoint of physical properties and moldability of the polyester copolymer.

The aliphatic dicarboxylic acid corresponding to the aliphatic dicarboxylic acid unit of the formula (III) or a derivative thereof is represented by HOOC-R ³ —COOH (R ³ represents a direct bond or a divalent aliphatic hydrocarbon group). Dicarboxylic acid, its lower alcohol ester or acid anhydride. In the formula, R ³ is preferably a direct bond or a linear alkylene group, and the linear alkylene usually has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms.
Examples of the carboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid and the like. Examples of the lower alcohol ester of dicarboxylic acid include esters of aliphatic alcohols having about 1 to 4 carbon atoms such as dimethyl ester, diethyl ester, and dibutyl ester. Examples of the acid anhydride include succinic anhydride and adipic anhydride. These can also be used as a mixture of two or more. Among these, succinic acid, succinic anhydride, or a mixture thereof is preferable from the viewpoint of the rigidity of the polyester copolymer.

  The ratio of each unit in the aliphatic polyester copolymer used in the present invention is as follows. That is, the unit of the formula (I) is 0 to 20 mol%, and the units of the formula (II) and the formula (III) are each selected from the range of 40 to 50 mol%. ) It is preferred that the proportions of units in the formula are equal. In order to further improve the laser weldability, the unit of the formula (I) is preferably 0 to 15 mol%, and the units of the formula (II) and the formula (III) are each in the range of 42.5 to 50 mol%. The range of 45 to 49.5 mol% is more preferable. The formula (I) is an arbitrary unit, but is preferably included as an essential unit, and the ratio in that case is usually 0.2 to 20 mol%, preferably 0.5 to 15 mol%, more preferably It is in the range of 1 to 10 mol%. When the number of units of the formula (I) is too small, the biodegradability effect of the obtained copolymer tends to be small, and when too large, the crystallinity of the obtained copolymer is lost, which is preferable for molding. There may not be.

  For example, as described in JP-A-8-239461, the aliphatic polyester copolymer is obtained by reacting a diol and a dicarboxylic acid corresponding to the units of the formulas (II) and (III) or a derivative thereof. When the aliphatic polyester is produced, the aliphatic oxycarboxylic acid corresponding to the unit of the formula (I) can be produced by copolymerization in an amount such that each unit has a predetermined amount.

  The amount of the diol corresponding to the formula (II) is substantially equimolar with respect to 100 mol of the dicarboxylic acid or derivative thereof (value based on the amount of dicarboxylic acid) corresponding to the formula (III). Considering distilling in, it is usually used in an excess of 1 to 20 mol%. The amount of the aliphatic oxycarboxylic acid corresponding to the formula (I) is usually 0 to 60 mol%, preferably 0.04 to 60%, relative to 100 mol of the dicarboxylic acid corresponding to the formula (II) or a derivative thereof. More preferably, it is 1 to 40 mol%, particularly preferably 2 to 20 mol%.

  The addition time of the aliphatic oxycarboxylic acid is not particularly limited as long as it is before the polycondensation reaction, and a method of adding at the same time as the catalyst when charging the raw material, a method of adding the catalyst by dissolving it in the oxycarboxylic acid solution in advance, etc. be able to.

  In the production of the aliphatic polyester copolymer, it is preferable to use a polymerization catalyst. Although it does not specifically limit as a polymerization catalyst, A germanium compound, for example, germanium oxide, is suitable. The usage-amount of a polymerization catalyst is 0.001 to 3 weight% normally with respect to the monomer amount to be used, Preferably it is 0.005 to 1.5 weight%.

  The polymerization reaction temperature is usually 150 to 260 ° C., preferably 180 to 230 ° C., the reaction time is usually 2 hours or more, preferably 4 to 15 hours, and the reaction pressure is usually 10 mmHg or less, preferably 2 mmHg or less.

  The number average molecular weight of the aliphatic polyester copolymer is preferably 10,000 to 200,000, more preferably 30,000 to 100,000. If the number average molecular weight is 10,000 or less, the mechanical strength tends to decrease, and if it exceeds 200,000, the moldability may deteriorate. In the present invention, the number average molecular weight is a molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) using, for example, “PLgel-10μ-MIX” as a column and a column temperature of 30 ° C.

  In addition to the structural units represented by the formulas (I) to (III), other copolymer components can be introduced into the aliphatic polyester copolymer within a range not impairing the effects of the present invention. Examples of other copolymer components include aromatic oxycarboxylic acids such as hydroxybenzoic acid, aromatic diols such as bisphenol A, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and polyvalent compounds such as trimethylolpropane and glycerin. Examples thereof include polyvalent oxycarboxylic acids such as alcohol and malic acid.

  The content of the aliphatic polyester copolymer (b) in the resin component (A) of the present invention is usually 1 to 99 parts by weight, preferably 10 to 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition (a). 90 parts by weight, more preferably 15 to 75 parts by weight. When the amount of the aliphatic polyester copolymer is too small, biodegradability of the resulting resin composition may be insufficient, and when it is too large, mechanical properties such as impact resistance of the resulting resin composition may be obtained. There is a tendency for the characteristics to deteriorate.

Reinforcing filler (B):
The reinforcing filler (B) is not particularly limited as long as it plays the role of improving the mechanical strength of the resin composition. For example, fibrous filler (glass fiber, carbon fiber, basalt fiber, silica / alumina fiber, zirconia fiber, boron fiber, boron nitride fiber, silicon nitride fiber, potassium titanate fiber, etc.), granular filler (kaolin, talc, etc.) Silicates such as wollastonite), plate-like fillers (mica, glass flakes, various metal foils, etc.), etc. can be exemplified, and two or more types can be used in combination depending on the properties required for the resin composition Can do. Of these fillers, fibrous fillers are preferable because they have high strength and rigidity.

  The fibrous filler preferably has an average fiber diameter of 1 to 100 μm, more preferably 2 to 50 μm, further preferably 2 to 30 μm, and particularly preferably 5 to 20 μm. Further, the shape of the cross section perpendicular to the fiber length direction is not limited to a circular shape, and may be a non-circular shape. When the cross section is non-circular, the flatness expressed by the ratio of the major axis to the minor axis (major axis / minor axis) is preferably in the range of 1.5 to 10. As the fibrous filler, glass fiber is preferable from the viewpoint of laser transmittance and reinforcing effect. For example, glass fiber can be used in the form of roving, chopped strand, etc., but when used in chopped strand, the fiber length is preferably 0.1 to 0.1 from the viewpoint of operability during production of the resin composition. 20 mm, more preferably 1 to 10 mm is used.

  Moreover, when using a fibrous filler, it is preferable to keep the fiber length of the fibrous filler in a molded article as long as possible from a viewpoint of laser transmittance and mechanical strength. The fiber length in the molded product is preferably 1 to 10 mm in terms of weight average fiber length, more preferably 1.5 to 10 mm, and even more preferably 2 to 8 mm. In order to keep the fiber length in the molded product long, it is necessary to keep the fiber length in the resin composition as long as possible at least in the stage of the resin composition used for molding. As a method for producing such a resin composition, for example, by pressing with a molten resin sheet from both sides of a fibrous filler mat and creating a rectangular parallelepiped with a sheet cutter, a pultrusion molding method, etc. For example, a method may be used in which a resin is coated on the surface of the roving filler to form a strand and then cut into pellets. Moreover, when manufacturing a resin composition pellet by melt kneading | mixing, it is necessary to select the kneading | mixing conditions that a reinforcement fiber is not damaged at the time of kneading | mixing.

  By blending the plate-like filler, the anisotropy and warpage of the molded product can be reduced. By blending the granular filler, the fluidity can be improved and the appearance of the surface of the molded product can be improved.

In general, the reinforcing filler (B) is preferably treated with a surface treatment agent in order to improve interfacial adhesion with the thermoplastic resin and to suppress opacity due to void formation at the interface.
Examples of the surface treatment agent include a coupling agent such as a silane coupling agent and a titanium coupling agent, an epoxy resin, an acrylic resin, a urethane resin, and a vinyl acetate resin, and preferably a silane coupling agent and an epoxy. Resin.
Examples of the silane coupling agent include amino silane, epoxy silane, allyl silane, and vinyl silane. Of these, aminosilanes are preferred. As the aminosilane coupling agent, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ- (2-aminoethyl) aminopropyltrimethoxysilane are preferable.
The epoxy resin is preferably a polyfunctional epoxy resin such as a phenol novolac type or a cresol novolac type.
In particular, it is preferable to use a silane coupling agent and / or an epoxy resin as a surface treatment agent, and an aminosilane coupling agent and / or a novolac type epoxy resin is more preferable. By making the surface treating agent such a structure, the inorganic functional group of the aminosilane coupling agent is the reinforcing filler (B) surface, and the organic functional group of the aminosilane coupling agent is the glycidyl group of the epoxy resin or the resin component. Since it reacts with (A) and the glycidyl group of the epoxy resin reacts with the resin component (A), the interfacial adhesion between the reinforcing filler (B) and the resin component (A) is improved. As a result, the mechanical strength of the resin composition of the present invention is improved, and further, the opaqueness due to void formation at the interface is reduced, so that the laser transmittance is also improved. Such an effect is remarkable when an aromatic polyester resin is used as the thermoplastic resin (a) constituting the resin component (A).

  When the silane coupling agent is included in the surface treatment agent, 0.1 to 8% by weight in the surface treatment agent is preferable, and 0.5 to 5% by weight is more preferable. Moreover, when an epoxy resin is included, 1 to 20 weight% in a surface treating agent is preferable and 2 to 10 weight% is more preferable. Further, the surface treatment agent can contain other components, for example, an antistatic agent, a lubricant, a water repellent, and the like without departing from the spirit of the present invention.

  The adhesion amount of the surface treatment agent is preferably 0.01 to 5% by weight, more preferably 0.05 to 2% by weight, based on the reinforcing filler (B). If the adhesion amount is less than 0.01% by weight, the effect of improving the mechanical strength may be small, and if it exceeds 2% by weight, the obtained effect does not change so much.

  Content of a reinforcement filler (B) is 0-100 weight part with respect to 100 weight part of resin components (A). The reinforcing filler may be blended arbitrarily, but preferably 10 to 100 parts by weight when blended. When the content of the reinforcing filler exceeds 100 parts by weight, the fluidity at the time of molding decreases, or the fibers are crushed by the interaction between the fibers / fibers, the fiber length in the molded product is shortened, and the mechanical strength In some cases, the laser transmittance may decrease.

Colorant (C):
You may mix | blend coloring agents, such as dye and a pigment, with the thermoplastic resin composition for laser welding of this invention. When blending a colorant, it is necessary to adjust the type and blending amount of the colorant to be used so as not to inhibit the laser transmittance.
As the dye, an anthraquinone-based, indigoid-based, perylene-based, perinone-based, azo-based, methine-based, phthalocyanine-based oil-soluble dye or disperse dye is preferable.
As the pigment, either an inorganic pigment or an organic pigment can be used. Examples of inorganic pigments include oxides, sulfides, sulfates, and carbon black. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, and dioxazine.
The content of the colorant (C) is preferably 0.005 to 5 parts by weight, more preferably 0.01 to 1 part by weight, still more preferably 0.03 to 0 parts per 100 parts by weight of the resin component (A). 8 parts by weight. If the blending amount exceeds 5 parts by weight, the dispersibility in the resin component may be reduced, the laser transmittance and mechanical strength may be reduced, and the colorant may bleed to the surface of the molded product.

Other additives:
The thermoplastic resin composition for laser welding of the present invention may be blended with other additives within a range not departing from the spirit of the present invention. Other additives include, for example, antioxidants, flame retardants, heat stabilizers, mold release agents, lubricants, plasticizers, catalyst deactivators, crystal nucleating agents, crystallization accelerators, ultraviolet absorbers, weathering stabilizers. , Antistatic agents, foaming agents, impact resistance improvers and the like. These additives can be added during or after the polymerization of the thermoplastic resin (a) or the aliphatic polyester copolymer (b).

The antioxidant has the effect of more effectively improving the heat aging resistance of the resin composition and further improving the mechanical strength retention such as color tone, tensile strength, and elongation. As antioxidant, it is preferable to mix | blend 1 or more types of antioxidant chosen from a phenolic antioxidant, sulfur type antioxidant, and phosphorus antioxidant. These antioxidants are particularly suitable when the thermoplastic resin (a) is an aromatic polyester resin.
The blending amount of the antioxidant is preferably 0.001 to 1.5 parts by weight, more preferably 0.03 to 1 part by weight with respect to 100 parts by weight of the resin component (A).

  The phenolic antioxidant means an antioxidant having a phenolic hydroxyl group, and among them, a hindered phenolic antioxidant is preferable. The hindered phenol antioxidant is an antioxidant in which one or two carbon atoms adjacent to the carbon of the aromatic ring to which the phenolic hydroxyl group is bonded are substituted by a substituent having 4 or more carbon atoms. Say. The substituent having 4 or more carbon atoms may be bonded to a carbon atom of the aromatic ring by a carbon-carbon bond, or may be bonded via an atom other than carbon.

  Non-hinders such as p-cyclohexylphenol, 3-t-butyl-4-methoxyphenol, 4,4′-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane as phenolic antioxidants Dophenol antioxidant, 2-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, 4-hydroxymethyl-2 , 6-di-t-butylphenol, styrenated phenol, 2,5-di-t-butylhydroquinone, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6- Xanthdiol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (6-tert-butyl-4-ethylphenol), 2,2′-methylenebis [4-methyl-6- (1,3,5-trimethylhexyl) phenol], 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 2 , 6-Bis (2-hydroxy-3-tert-butyl-5-methylbenzyl) -4-methylphenol, 1,1,3-tris [2-methyl-4-hydroxy Loxy-5-t-butylphenyl] butane, 1,3,5-trimethyl-2,4,6-tris [3,5-di-t-butyl-4-hydroxybenzyl] benzene, tris (3,5- Di-t-butyl-4-hydroxybenzyl) isocyanurate, tris [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 4,4′-thiobis (3- Methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), 4,4′-thiobis (2-methyl-6-tert-butylphenol), thiobis (β-naphthol) Hindered phenolic antioxidants, and the like. In particular, hindered phenol-based antioxidants can be suitably used as radical trapping agents because they tend to be stable radicals themselves. The molecular weight of the hindered phenol antioxidant is usually 200 or more, preferably 500 or more, and the upper limit is usually 3000.

  The sulfur-based antioxidant in the present invention refers to an antioxidant having a sulfur atom. For example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3 -Dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropyl Examples include xanthate and trilauryl trithiophosphite. In particular, a thioether-based antioxidant having a thioether structure can be suitably used because it receives oxygen from an oxidized substance and reduces it. The molecular weight of the sulfur-based antioxidant is usually 200 or more, preferably 500 or more, and the upper limit is usually 3000.

The phosphorus antioxidant in the present invention refers to an antioxidant having a phosphorus atom, and is preferably an antioxidant having a P (OR) ₃ structure. Here, R is an alkyl group, an alkylene group, an aryl group, an arylene group, etc., and three Rs may be the same or different, and any two Rs are bonded to each other to form a ring structure. It may be.
Examples of phosphorus antioxidants include triphenyl phosphite, diphenyl decyl phosphite, phenyl diisodecyl phosphite, tri (nonylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphos. Phyto, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, etc. are mentioned.

  The blending amount of the antioxidant is preferably 0.001 to 1.5 parts by weight, more preferably 0.03 to 1 part by weight with respect to 100 parts by weight of the resin component (A). If the amount of the phenolic antioxidant is less than 0.001 part by weight, the antioxidant effect may be insufficient. If the amount exceeds 1.5 parts by weight, the resin tends to decompose during melt-kneading. It is in.

The flame retardant is not particularly limited, and examples thereof include organic halogen compounds, antimony compounds, phosphorus compounds, other organic flame retardants, and inorganic flame retardants.
Examples of the organic halogen compound include brominated polycarbonate, brominated epoxy resin, brominated phenoxy resin, brominated polyphenylene ether resin, brominated polystyrene resin, brominated bisphenol A, and pentabromobenzyl polyacrylate.
Examples of the antimony compound include antimony trioxide, antimony pentoxide, and sodium antimonate.
As a phosphorus compound, phosphate ester, polyphosphoric acid, ammonium polyphosphate, red phosphorus etc. are mentioned, for example.
Examples of other organic flame retardants include nitrogen compounds such as melamine, cyanuric acid, and cyanuric acid melamine.
Examples of the inorganic flame retardant include aluminum hydroxide, magnesium hydroxide, silicon compound, and boron compound.
These flame retardants are particularly suitable when the thermoplastic resin (a) is an aromatic polyester resin.
The blending amount of the flame retardant is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 40 parts by weight with respect to 100 parts by weight of the resin component (A). If the blending amount is less than 0.1 parts by weight, the effect of improving the flame retardancy may be low, and if it exceeds 50 parts by weight, the mechanical strength tends to decrease.

In addition, a method of blending a lubricant to lower the resin melt viscosity at the time of molding and suppressing the occurrence of distortion of the molded product, or a method of blending a plasticizer to improve resin fluidity is also effective. It is also preferable to add a release agent in order to improve the mold release property at the time of molding and further suppress the occurrence of distortion of the molded product. Examples of the mold release agent include fatty acid metal salts such as stearic acid metal salts and montanic acid metal salts, aliphatic hydrocarbon compounds, higher alcohols, amide compounds, ester compounds and the like, which affect the mechanical properties. It is preferable to add in the range not given.
The blending amount of the lubricant, the plasticizer, and the release agent is preferably 0.01 to 5 parts by weight, more preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the resin component (A). A lubricant, a plasticizer, and a release agent may be added during the production of the resin composition, or may be dry blended with the obtained resin composition and used for molding.

  In the present invention, a thermosetting resin such as a phenol resin, a melamine resin, a silicone resin, and an epoxy resin can be blended with the thermoplastic resin composition within a range not impairing the effects of the present invention. These thermosetting resins may be used in combination of two or more. When mix | blending a thermosetting resin, Preferably it is 0.1-50 weight part with respect to 100 weight part of resin components (A), More preferably, it is 0.5-40 weight part.

The resin composition can be produced by a known general method, among which melt kneading is preferable. For melt kneading, various extruders, Brabender plastographs, lab plast mills, kneaders, Banbury mixers and the like are used. In this invention, the method of using the uniaxial or biaxial extruder which has the equipment which can be devolatilized from a vent port as a kneading machine is further more preferable.
The thermoplastic resin (a), the aliphatic polyester copolymer (b), the reinforcing filler (B) blended as necessary, and other additives may be introduced from the root of the melt kneader and melt kneaded. When the reinforcing filler (B) is included, the reinforcing filler may be side-feeded and melt-kneaded. The thermoplastic resin (a), the aliphatic polyester copolymer (b), the reinforcing filler (B) blended as necessary, and other additives may be preliminarily used in a ribbon blender, a Henschel mixer, a drum blender, etc. It may be mixed or may not be mixed. When mixing in advance, it is preferable to adjust the mixing time and the number of rotations so that the reinforcing filler is not damaged as much as possible.

  When the thermoplastic resin (a) is crystalline, the heating temperature at the time of melt kneading is usually in a temperature range 30 to 100 ° C. higher than the melting point, and when the thermoplastic resin (a) is an amorphous resin, A temperature range that is 80 to 150 ° C. higher than the glass transition temperature is employed. When the thermoplastic resin (a) is the above-mentioned engineering plastic, a range of 220 to 300 ° C. is usually adopted. In order to reduce the pressure of the molten resin during melt kneading, the plasticizing temperature of the molten resin is usually set. It is preferable to set a higher value. For example, when a polybutylene terephthalate resin is used as the thermoplastic resin (a), it is preferable to set the barrel temperature of a melt kneading apparatus such as an extruder to 260 to 280 ° C.

  As a method for molding the thermoplastic resin composition used in the present invention, a molding method generally used for thermoplastic resins, that is, a molding method such as injection molding, hollow molding, extrusion molding, or press molding can be applied. . A particularly preferable molding method is injection molding or extrusion molding from the viewpoint of good fluidity and easy to obtain a molded product having an accurate welded portion, and injection molding is particularly preferable.

The thermoplastic resin composition for laser welding of the present invention is assembled into various molded products by integrating with other members by setting the light transmittance at a wavelength of 840 nm to 20% or more in a molded product having a thickness of 1 mm, for example. It becomes easy. By using such a laser welding thermoplastic resin composition, at least one member using the laser welding thermoplastic resin composition can be firmly welded to each other, and molding having two or more resin members It can be preferably used to produce a product.
The shape of the member is not particularly limited, but the members can be more firmly welded particularly when the main component of the thermoplastic resin (a) is an aromatic polyester resin.
In laser welding, laser light that has passed through a laser-transmitting member is absorbed by the laser-absorbing member, melted, and both members are welded. Since the thermoplastic resin composition for laser welding used in the present invention has high permeability to laser light, it can be preferably used as a member that transmits laser light. For example, the thickness of the member through which the laser beam is transmitted (thickness in the direction in which the laser beam is transmitted) can be appropriately determined in consideration of the application, the composition of the composition, and the like, but is, for example, 5 mm or less, preferably 4 mm or less. It is.

Examples of laser light sources used for laser welding include gas lasers such as Ar laser (510 nm), He—Ne laser (630 nm), and CO ₂ laser (10600 nm), liquid lasers such as dye laser (400 to 700 nm), and YAG lasers. A solid laser such as (1064 nm) or a semiconductor laser (655 to 980 nm) can be used. A semiconductor laser is preferably used in terms of beam quality and cost. Further, the laser type can be appropriately selected depending on the type of the welding partner material.

At the time of laser welding, first, the welded portions of the first member made of the thermoplastic resin composition for laser welding of the present invention and the second member made of the thermoplastic resin composition are brought into contact with each other. The shape of the member is not particularly limited, but is usually a shape having at least a surface contact portion (plane or curved surface) because the members are joined by laser welding. The welded portions of both members are preferably in contact with each other on the surface, but may be flat surfaces, curved surfaces, or a combination of flat surfaces and curved surfaces. Next, laser light is irradiated (preferably irradiated perpendicularly to the adhesive surface) from the first member side made of the thermoplastic resin composition for laser welding of the present invention. At this time, the laser beam may be condensed at the interface between the two using a lens system if necessary. The condensed beam passes through the first member made of the laser welding resin composition, is absorbed near the surface of the second member made of the thermoplastic resin composition, generates heat, and melts. Next, the heat is transferred to the first member made of the laser-welded resin composition by heat conduction to melt it, and a molten pool is formed at the interface between the two. When cooled, the molten pool solidifies and bonds together.
The composite molded product in which members are welded in this manner has a high bonding strength. In addition, the composite molded product in the present invention refers to a product in which at least two or more members are welded, and includes a member that forms a part of these in addition to a finished product or a part.

The second member made of the thermoplastic resin composition is not particularly limited as long as it contains at least a thermoplastic resin and can be welded to the first member made of the laser welding thermoplastic resin composition. As a thermoplastic resin contained in this thermoplastic resin composition, what was illustrated by the thermoplastic resin (a) used for a 1st member can be used individually or in combination of 2 or more types. In addition, when the aliphatic polyester copolymer (b) is blended and used in the thermoplastic resin composition used for the second member, it is 40% by weight or less in the resin component of the thermoplastic resin composition. Preferably there is. More preferably, the thermoplastic resin component of the thermoplastic resin composition used for the second member is the same type as the thermoplastic resin (a) of the laser welding thermoplastic resin composition used for the first member, Moreover, it may be the same as the thermoplastic resin composition for laser welding used for the first member. The resin used for the second member is preferably one having an absorption wavelength within the range of the laser light wavelength to be irradiated.

  Furthermore, you may make it absorb a laser beam by making the thermoplastic resin composition used for a 2nd member add and contain a light absorber, for example, a coloring pigment. Examples of such colored pigments include black pigments such as carbon black (for example, acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, etc.), red pigments such as iron oxide red, and molybdate. Examples thereof include inorganic pigments such as orange pigments such as orange, white pigments such as titanium oxide, and organic pigments such as yellow pigments, orange pigments, red pigments, blue pigments, and green pigments. Among these, inorganic pigments generally have a strong hiding power and can be suitably used for the thermoplastic resin composition used for the second member on the laser absorption side. Two or more of these light absorbers may be used in combination, and the blending amount is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the resin component.

  The composite molded product obtained in the present invention has high welding strength and less damage to the resin due to laser light irradiation. Therefore, the composite molded product has various uses such as electrical / electronic parts, office automate (OA) equipment parts, and home appliances. It can be applied to equipment parts, machine mechanism parts, automobile mechanism parts, and the like. In particular, it can be suitably used for housings such as automotive electrical parts (various control units, ignition coil parts, etc.), motor parts, various sensor parts, connector parts, switch parts, relay parts, coil parts, transformer parts, lamp parts, etc. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example at all unless the summary is exceeded. In addition, the measuring method of the evaluation item of the raw material used in the following Examples and the obtained resin composition is as follows.

[Measuring method]
(1) Light transmittance The light transmittance was measured about the test piece for light transmittance measurement (length 128mm, width 13mm, thickness 1mm) obtained by the method of the following description. The light transmittance was measured using a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation: “UV-3100PC”) at a wavelength of 840 nm. The evaluation results are shown in Table 1.

(2) Laser welding strength As shown in FIG. 1, the test pieces were overlapped and irradiated with laser. In FIG. 1, (i) shows a view of the test piece as viewed from the side, and (ii) shows a view of the test piece as seen from above. 1 is a test piece (hereinafter referred to as “test piece 1”) made of the thermoplastic resin composition for laser welding of Examples or Comparative Examples, and 2 is a thermoplastic resin composition for a second member which is a mating material to be joined. A test piece made of an object (hereinafter referred to as “test piece 2”) 3 indicates a laser irradiation spot. Each test piece was produced on the same conditions as the production conditions of the test piece for (1) light transmittance measurement. The test piece 1 was overlapped with the laser transmission side and the test piece 2 was overlapped with the laser absorption side, and the laser was irradiated from the transmission side. As the laser welding apparatus, “FD-100” manufactured by Fine Device Co., Ltd., the laser light wavelength is 840 nm, the focal spot diameter is 0.6 mm, the scanning speed is 5 mm / sec, Example 4 and Comparative Example 4 have a laser output of 20 W, In other examples and comparative examples, scanning was performed in the width direction of the test piece (13 mm) under the condition of a laser output of 12 W, and laser light was irradiated.
Using the welded specimen, laser welding strength was measured. The welding strength is measured by using a tensile tester (Instron “5544”), and welding and integrating the test pieces 1 and 2 with clamps at both ends in the major axis direction. Evaluation was performed by pulling at 5 mm / min. The laser welding strength is indicated by the tensile shear fracture strength of the welded portion. The evaluation results are shown in Table 1.

(3) Tensile strength Tensile strength of the ISO test piece for tensile strength measurement obtained by the method described below was measured according to the ISO527 standard. The evaluation results are shown in Table 1.

(4) Charpy impact strength About the ISO test piece for Charpy measurement obtained by the following method, the Charpy impact strength with a notch was measured based on ISO179 standard. The evaluation results are shown in Table 1.

(5) Analytical polymer composition of aliphatic polyester copolymer:
^The composition was calculated by the area ratio of the measured spectrum by ¹ H-NMR method.
Number average molecular weight (Mn):
Aliphatic polyester copolymer was dissolved in chloroform and measured by polystyrene conversion using “GPC HLC-8020” manufactured by Tosoh Corporation. The column was “PLgel-10μ-MIX”, and measurement was performed under the condition of a column temperature of 30 ° C.

[raw materials]
(A-1) PBT resin: polybutylene terephthalate resin, manufactured by Mitsubishi Engineering Plastics Co., Ltd. “trade name: NOVADURAN (registered trademark) 5020”
(A-2) PC resin: polycarbonate resin, manufactured by Mitsubishi Engineering Plastics Co., Ltd. “Product name: Iupilon (registered trademark) S-3000FN”
(A-3) PA resin: polyamide 6 resin, Mitsubishi Engineering Plastics Co., Ltd. “Product name: Novamid (registered trademark) 1013J”
(A-4) POM resin: polyacetal resin, manufactured by Mitsubishi Engineering Plastics Co., Ltd. “Product name: Iupital (registered trademark) V-20-1”
(A-5) PPE resin: polyphenylene ether resin, “trade name: PX100L” manufactured by Polyxylenol Singapore
(A-6) PS resin: polystyrene resin, manufactured by Nippon Polystyrene Co., Ltd., “trade name: HF77”

(B-1) Aliphatic polyester-1: It was produced according to the following Production Example 1 using succinic acid, 1,4-butanediol and lactic acid as raw materials.

Production Example 1:
A reaction vessel with a capacity of 100 ml provided with a stirrer, a nitrogen introducing tube, a heating device, a thermometer, and an auxiliary agent addition port contains 35.4 g of succinic acid, 28.4 g of 1,4-butanediol and 1% by weight of germanium oxide. 2.9 g of lactic acid aqueous solution was charged. Under stirring, nitrogen gas was introduced into the reaction vessel, heated to 180 ° C. in a nitrogen gas atmosphere, reacted for 45 minutes, decompressed to 20 mmHg, and further reacted for 1.75 hours. Then, it was made to react on the conditions of 220 degreeC and 0.5 mmHg for 4 hours. The polymer composition of the obtained copolymer was 4.6 mol% lactic acid units, 47.7 mol% each of 1,4-butanediol units and succinic acid units, and the number average molecular weight was 58,900.

(B-2) Aliphatic polyester-2: Succinic acid, 1,4-butanediol, and glycolic acid were used as raw materials and produced according to Production Example 2 described later.

Production Example 2:
A 300-ml reaction vessel equipped with a stirrer, nitrogen inlet tube, heating device, thermometer, and auxiliary agent inlet contains 118.1 g of succinic acid, 99.1 g of 1,4-butanediol and 1% by weight of germanium oxide. 6.3 g of a 70 wt% glycolic acid aqueous solution was charged. Under stirring, nitrogen gas was introduced into the reaction vessel, heated to 185 ° C. in a nitrogen gas atmosphere, reacted for 0.5 hours, and then the internal temperature was raised to 220 ° C. and reacted for 0.5 hours. Then, it was made to react on 220 degreeC and the conditions of 0.5 mmHg for 6 hours. The polymer composition of the obtained copolymer was 2.4 mol% of glycolic acid units, 48.8 mol% of 1,4-butanediol units and succinic acid units, respectively, and the number average molecular weight was 42,500.

(B-3) Aliphatic polyester-3: Polylactic acid (aliphatic oxycarboxylic acid unit 100 mol%), “trade name: Lacia H-400” manufactured by Mitsui Chemicals, Inc.
(B) Glass fiber: chopped strand, “trade name: ECT03T-127” manufactured by Nippon Electric Glass Co., Ltd., fiber diameter 13 μm, cut length 3 mm

(C) Colorant masterbatch: A thermoplastic resin masterbatch produced by blending a phthalocyanine-based and methine-based oil-soluble dye-based colorant with polybutylene terephthalate resin (trade name: eBIND LTW- manufactured by Orient Chemical Industries, Ltd.) 8950C ", colorant content about 6% by weight
Antioxidant: Hindered phenol-based antioxidant, manufactured by Ciba Specialty Chemicals “trade name: Irganox 1010”)

[Examples 1-8 and Comparative Examples 1-8]
A thermoplastic resin and an aliphatic polyester copolymer are dry blended at a blending ratio shown in Table 1, and are put into a hopper of a twin screw extruder (“TEX30HSST, L / D = 42” manufactured by Nippon Steel Works) and discharged. The mixture was melt-kneaded and pelletized under the conditions of an amount of 20 kg / h, a screw rotational speed of 150 rpm, and a barrel temperature of 260 ° C. to obtain thermoplastic resin composition pellets for the first member. The glass fiber was supplied from the side feeder of the twin screw extruder and pelletized in the same manner.
Using the obtained resin composition pellets, a test piece for measuring light transmittance and laser welding strength (length 128 mm, width 13 mm) with an injection molding machine (“Model: SE-50D” manufactured by Sumitomo Heavy Industries, Ltd.) , Thickness 1 mm). In addition, ISO test pieces for tensile strength measurement and Charpy impact test were prepared with an injection molding machine (“Model: SG-75MIII” manufactured by Sumitomo Heavy Industries, Ltd.). These injection moldings were performed at a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C.
As the thermoplastic resin composition for the second member to be laser-welded to the first member, carbon black (Mitsubishi Chemical Co., Ltd.) was added to each of the resin compositions of Examples and Comparative Examples. 1) "Product name: MA600B") was blended in an amount of 0.5% by weight, and the one prepared under the same conditions as the thermoplastic resin composition for the first member was used. Using the obtained thermoplastic resin composition for the second member, a test piece was prepared under the same conditions as the above (1) test piece for measuring light transmittance.

  From Table 1, it was clarified that by using a specific aliphatic polyester copolymer, a resin composition having improved laser transmittance, excellent laser welding characteristics, and good mechanical properties (see FIG. Examples 1-8). Further, by using the thermoplastic resin composition of the present invention, strong laser welding with other members can be easily performed.

  By using the thermoplastic resin composition of the present invention, laser permeability, laser welding characteristics, and mechanical properties are improved, and it is possible to provide an integrally molded product in which members are bonded more firmly. Such molded products are widely used industrially, and are particularly suitable for electrical / electronic parts, office automate (OA) equipment parts, home appliance parts, machine mechanism parts, vehicle mechanism parts, vehicle hollow parts, and the like. Yes, its utility value is extremely high.

FIG. 1 is a schematic view showing a laser welding strength measuring method in an embodiment of the present invention.

Explanation of symbols

1 Test piece 1
2 Test piece 2
3 Laser irradiation points

Claims (8)

A resin composition comprising 0 to 100 parts by weight of a reinforcing filler (B) to 100 parts by weight of a resin component (A) composed of a thermoplastic resin (a) and an aliphatic polyester copolymer (b). The aliphatic polyester copolymer (b) is an aliphatic oxycarboxylic acid unit represented by the following formula (I): 0 to 20 mol%, an aliphatic or alicyclic group represented by the following formula (II): A thermoplastic resin composition for laser welding, comprising 40 to 50 mol% of a formula diol unit and 40 to 50 mol% of an aliphatic dicarboxylic acid unit represented by the following formula (III).

(Wherein R ¹ represents a divalent aliphatic hydrocarbon group, R ² represents a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group, and R ³ represents a direct bond or a divalent group. Represents an aliphatic hydrocarbon group.)   The mol% of the aliphatic or alicyclic diol unit represented by the formula (II) and the mol% of the aliphatic dicarboxylic acid unit represented by the formula (III) are 45 to 49.5 mol%, respectively. The thermoplastic resin composition for laser welding according to claim 1, which is in a range. R ^{2 in the} formula (II) is a linear alkylene group having 2 to 10 carbon atoms or a cycloalkylene group having 3 to 10 carbon atoms, and R ^{3 in the} formula (III) is a direct bond or 1 carbon atom. The thermoplastic resin composition for laser welding according to claim 1, wherein the thermoplastic resin composition is 10 to 10 linear alkylene groups.   The thermoplastic resin composition for laser welding according to any one of claims 1 to 3, wherein the reinforcing filler (B) is a glass fiber.   Furthermore, the colorant (C) is contained in an amount of 0.01 to 1 part by weight with respect to 100 parts by weight of the resin component (A) composed of the thermoplastic resin (a) and the aliphatic polyester copolymer (b). The thermoplastic resin composition for laser welding according to any one of claims 1 to 4.   The thermoplastic resin composition for laser welding according to any one of claims 1 to 5, which is used for a member on a laser transmission side.   A first member made of the thermoplastic resin composition for laser welding according to any one of claims 1 to 6 and a second member made of a thermoplastic resin composition are brought into close contact with each other, and the first member side Composite molded product produced by welding with laser light.   A first member made of the thermoplastic resin composition for laser welding according to any one of claims 1 to 6 and a second member made of a thermoplastic resin composition are brought into close contact with each other, and the first member side The manufacturing method of the composite molded product including the process of irradiating with laser beam and welding.

Images