JP5884102B2 - Laser welding resin composition and welded body thereof - Google Patents

Description

  The present invention relates to a laser-welded resin composition and a welded body, and more specifically, a laser-welded polyester-based resin composition excellent in laser welding processability and moldability, and a molded article comprising the same. The present invention relates to a laser welded body.

Thermoplastic polyester resin is excellent in mechanical strength, chemical resistance, electrical insulation, etc., and has excellent heat resistance, moldability, and recyclability, so it is widely used in various equipment parts. ing.
In recent years, in order to manufacture these device parts, examples of joining parts by welding for increasing productivity have been increasing, and laser welding, which has little influence on electronic parts, has been frequently used.

However, compared to polycarbonate resins and polystyrene resins, polyester resins, especially polybutylene terephthalate resins, are relatively low in laser transmission, and because the molded product tends to warp, the welding strength may be insufficient. There were many.
When warping occurs in the molded product, a method of applying a pressing force to correct the warping at the time of welding is also used, but depending on the shape of the molded product, it is often difficult to apply the pressing force efficiently. Since residual stress remains in the welded body from which the pressing force has been removed, there is a problem that high weld strength is difficult to obtain.

In order to improve the laser weldability of the polybutylene terephthalate resin, a method using a copolymerized polybutylene terephthalate (Patent Document 1), and a method of alloying a polycarbonate resin or a styrene resin to the polybutylene terephthalate (Patent Documents 2 and 3). ), And a method of adding a specific oligomer (Patent Document 4) has been proposed.
However, in these methods, sufficient weldability may not be obtained due to a gap between welding members caused by warpage deformation of a molded product.
In addition, a method for improving weldability by adding a laser transmission absorbent such as nigrosine to a thermoplastic resin has been proposed (Patent Document 5), but a polyester resin composition suitable for laser welding has not been described. Absent.

Japanese Patent No. 3510817 Japanese Patent Laid-Open No. 2003-292752 Japanese Patent No. 4641377 JP 2004-315805 A JP 2008-1112 A

  An object of the present invention is to provide a laser-welded polyester resin composition having excellent laser welding processability and excellent moldability.

The present inventor uses a resin composition in which polybutylene terephthalate resin is blended with a specific other resin, a specific laser light-absorbing dye, and a reinforcing filler, an epoxy compound, a flow modifier, and the like as necessary. Thus, the present inventors have found that a resin composition having excellent moldability and extremely excellent laser welding processability can be provided, and the present invention has been completed.
That is, according to the present invention, the following laser welding resin composition and welded body are provided.

[1] A resin composition used for laser beam welding,
(A) a polybutylene terephthalate resin and (B) at least one resin selected from the following (B-1) to (B-5), based on a total of 100 parts by mass of (A) and (B): (A) 50 to 95 parts by mass, (B) 50 to 5 parts by mass,
Furthermore, for a total of 100 parts by mass of (A) and (B),
(D) 0 to 120 parts by mass of reinforcing filler, (E) 0 to 5 parts by mass of epoxy compound, (F) 0 to 10 parts by mass of flow modifier, and (G) nigrosine, aniline black, phthalocyanine 0.001-0.2 parts by mass of one or more laser light absorbing dyes selected from naphthalocyanine, porphyrin, perylene, quaterylene, azo dyes, anthraquinones, squaric acid derivatives and immonium,
A laser-welded resin composition having a converted absorbance a (absorbed with respect to laser light having a wavelength of 940 nm, converted to 1 mm thickness) of 0.2 to 2.
(B-1) Polyethylene terephthalate resin (B-2) Polycarbonate resin (B-3) Aromatic vinyl resin (B-4) Acrylic resin (B-5) Polyamide resin [2] (A) Poly The resin composition for laser welding as described in [1] above, wherein the butylene terephthalate resin is a polybutylene terephthalate homopolymer and / or a polybutylene terephthalate copolymer copolymerized with isophthalic acid and / or polyalkylene glycol. object.
[3] The above [1] or [2], wherein (D) the reinforcing filler is a glass fiber having an anisotropic cross-sectional shape in which the ratio of the major axis to the minor axis in the cross section is 1.5 to 10 The resin composition for laser welding as described in 1.
[4] Any of the above [1] to [3], wherein the flow modifier (F) is at least one selected from the following (F-1) to (F-4): The resin composition for laser welding as described in 1.
(F-1) Styrene oligomer (F-2) Olefin oligomer (F-3) Acrylic oligomer (F-4) Polyfunctional compound

[5] A laser welding molded article obtained by molding the laser welding resin composition according to any one of [1] to [4].
[6] A laser welded body laser-welded using the molded body according to [5] above.
[7] The laser welded body according to the above [6], wherein the welded body has a gap of 0.1 mm or more when the welded body is welded at least at a part of the welded portion.
[8] The laser welded body according to [6] or [7], wherein the ends of the molded body are butted against each other.

The resin composition for laser welding of the present invention is excellent in laser welding processability and moldability, and a welded body obtained by laser welding a molded body of the resin composition is excellent in welding strength and durability.
Moreover, the resin composition for laser welding of the present invention is characterized in that its converted absorbance a is adjusted to be in the range of 0.2 to 2, thereby balancing the transmission and absorption of laser light. Therefore, we can provide polyester resin material that can be laser welded with only one type of resin material without using two types of laser light transmitting resin and laser light absorbing resin unlike conventional laser welding. It becomes possible to do. And by having such a converted absorbance a, when the molded body from the resin composition of the present invention has a gap between the members for joining due to sink marks or warpage during molding, no pressing force is particularly applied. Even if there is a gap in the state, laser welding is possible even if the gap is 0.1 mm or more, particularly 1 mm or more, and extremely excellent workability can be exhibited in actual welding processing.

It is a conceptual diagram which shows the evaluation methods, such as the welding strength in an Example. It is a conceptual diagram which shows the evaluation method of butt welding in an Example. It is a perspective view which shows the shape of plate-shaped molded product # 3 used for welding in the Example. It is a perspective view which shows the shape of box-shaped molded product # 4 used for welding in the Example.

[Summary of Invention]
The laser welding resin composition of the present invention is a resin composition used for welding by laser light,
(A) a polybutylene terephthalate resin and (B) at least one resin selected from the following (B-1) to (B-5), based on a total of 100 parts by mass of (A) and (B): (A) 50 to 95 parts by mass, (B) 50 to 5 parts by mass,
Furthermore, for a total of 100 parts by mass of (A) and (B),
(D) 0 to 120 parts by mass of reinforcing filler, (E) 0 to 5 parts by mass of epoxy compound, (F) 0 to 10 parts by mass of flow modifier, and (G) nigrosine, aniline black, phthalocyanine 0.001-0.2 parts by mass of one or more laser light absorbing dyes selected from naphthalocyanine, porphyrin, perylene, quaterylene, azo dyes, anthraquinones, squaric acid derivatives and immonium,
The converted absorbance a (absorbance with respect to laser light having a wavelength of 940 nm, converted to 1 mm thickness) is 0.2 to 2.
(B-1) Polyethylene terephthalate resin (B-2) Polycarbonate resin (B-3) Aromatic vinyl resin (B-4) Acrylic resin (B-5) Polyamide resin

Hereinafter, the contents of the present invention will be described in detail.
The description of each constituent element described below may be made based on typical embodiments and specific examples of the present invention, but the present invention is interpreted to be limited to such embodiments and specific examples. It is not a thing. In the specification of the present application, “to” is used in the sense of including the numerical values described before and after it as the lower limit value and the upper limit value.

[(A) Polybutylene terephthalate resin]
The (C) polybutylene terephthalate resin (hereinafter also abbreviated as “PBT resin”) which is the main component of the (C) polybutylene terephthalate resin composition constituting the resin composition of the present invention. 1 shows a polymer having a structure in which a terephthalic acid unit and a 1,4-butanediol unit are ester-bonded. That is, in addition to polybutylene terephthalate resin (homopolymer), polybutylene terephthalate copolymer containing other copolymer components other than terephthalic acid units and 1,4-butanediol units, and homopolymers and copolymers thereof Including the mixture.

  The PBT resin may contain dicarboxylic acid units other than terephthalic acid. Specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,5-naphthalenedicarboxylic acid. 2,6-naphthalenedicarboxylic acid, biphenyl-2,2′-dicarboxylic acid, biphenyl-3,3′-dicarboxylic acid, biphenyl-4,4′-dicarboxylic acid, bis (4,4′-carboxyphenyl) methane , Aromatic dicarboxylic acids such as anthracene dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid, and adipic acid , Aliphatic dicarboxylic acids such as sebacic acid, azelaic acid, dimer acid, etc. It is below.

  The diol unit may contain other diol units in addition to 1,4-butanediol. Specific examples of the other diol units include aliphatic or alicyclic diols having 2 to 20 carbon atoms. And bisphenol derivatives. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane. 4,4′-dicyclohexylhydroxypropane, bisphenol A ethylene oxide addition diol, and the like. Furthermore, triols such as glycerin and trimethylolpropane are also included.

  The PBT resin is preferably a polybutylene terephthalate homopolymer obtained by polycondensation of terephthalic acid and 1,4-butanediol. In addition, as the carboxylic acid unit, one or more dicarboxylic acids other than the terephthalic acid and / or diol are used. The unit may be a polybutylene terephthalate copolymer containing one or more diols other than the 1,4-butanediol. In the PBT resin, from the viewpoint of mechanical properties and heat resistance, the proportion of terephthalic acid in the dicarboxylic acid unit is preferably 70 mol% or more, more preferably 90 mol% or more. Similarly, the proportion of 1,4-butanediol in the diol unit is preferably 70 mol% or more, more preferably 90 mol% or more.

  In addition to the above-mentioned bifunctional monomers, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane are introduced to introduce a branched structure, and fatty acids are used for molecular weight control. A small amount of a monofunctional compound can be used in combination.

The PBT resin is manufactured by batch polymerization or continuous polymerization of a dicarboxylic acid component mainly composed of terephthalic acid or an ester derivative thereof and a diol component mainly composed of 1,4-butanediol. Can do. In addition, after a low molecular weight polybutylene terephthalate resin is produced by melt polymerization, solid state polymerization can be performed under a nitrogen stream or under reduced pressure to increase the degree of polymerization (or molecular weight) to a desired value.
The PBT resin is preferably produced by a continuous melt polycondensation of a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component.

  The catalyst used in performing the esterification reaction may be a conventionally known catalyst, and examples thereof include a titanium compound, a tin compound, a magnesium compound, and a calcium compound. Of these, titanium compounds are particularly preferred. Specific examples of the titanium compound as the esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

The PBT resin may be a polybutylene terephthalate resin modified by copolymerization. As a specific preferred copolymer thereof, a polyalkylene glycol (particularly, polytetramethylene glycol (PTMG)) is copolymerized. Examples include polyester ether resins, dimer acid copolymerized polybutylene terephthalate resins, and particularly isophthalic acid copolymerized polybutylene terephthalate resins. These copolymers are those having a copolymerization amount of 1 mol% or more and less than 50 mol% in all segments of the PBT resin. Among them, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 20 mol%.
And the preferable content of these copolymers is 10-100 mass% in the total amount of 100 mass% of (A) polybutylene terephthalate resin, Furthermore, 30-100 mass%, Especially it is 50-100 mass%. is there.

  The intrinsic viscosity of the PBT resin is preferably 0.5 to 2 dl / g. From the viewpoint of moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are preferred. If the intrinsic viscosity is lower than 0.5 dl / g, the resulting resin composition tends to have a low mechanical strength. On the other hand, if it is higher than 2 dl / g, the fluidity of the resin composition may be deteriorated and the moldability may be deteriorated or the laser weldability may be deteriorated. The intrinsic viscosity is measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

[(B) Resin]
The above-mentioned (A) polybutylene terephthalate resin (PBT resin) contains (B) resin selected from the following (B-1) to (B-5), and (C) polybutylene terephthalate resin composition: Composing things.
(B-1) Polyethylene terephthalate resin (B-2) Polycarbonate resin (B-3) Aromatic vinyl resin (B-4) Acrylic resin (B-5) Polyamide resin These resins are basically The crystallinity is low and the crystallinity is preferably lower than that of the (A) polybutylene terephthalate resin. Accordingly, the resin composition of the present invention has a feature of high laser light transmittance.
Hereinafter, the resins (B-1) to (B-5) will be described.

(B-1) Polyethylene terephthalate resin The polyethylene terephthalate resin may be produced by either a transesterification reaction between dimethyl terephthalate and ethylene glycol or a direct esterification reaction between terephthalic acid and ethylene glycol.
In addition, polyethylene terephthalate resin is used in the polycondensation reaction, together with terephthalic acid or its dialkyl ester, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, trimellitic acid and their dialkyl esters, etc. These dibasic acids, tribasic acids, and the like, and dialkyl esters thereof can also be used. It is preferable that these usage-amounts are the range of 50 mass parts or less with respect to 100 mass parts of terephthalic acid or its dialkyl ester.

  Also, during the polycondensation reaction, together with ethylene glycol, other aliphatic glycols such as propylene glycol, 1,4-butanediol, hexamethylene glycol, etc., and other than aliphatic glycols such as cyclohexanediol, cyclohexanedimethanol, Other diols such as xylene glycol, 2,2-bis (4-hydroxyphenyl) propane, glycerin, pentaerythritol, and polyhydric alcohols can be used in combination. The amount of these diols or polyhydric alcohols used is preferably in the range of 40 parts by mass or less with respect to 100 parts by mass of the aliphatic glycol. It is preferable that these usage-amounts are the range of 50 mass parts or less with respect to 100 mass parts of terephthalic acid or its dialkyl ester.

  As described above, the polyethylene terephthalate resin may be a polyethylene terephthalate resin modified by copolymerization. Specific preferred copolymers include polyalkylene glycols (particularly polytetramethylene glycol (PTMG)). ), A dimer acid copolymerized polyethylene terephthalate resin, particularly an isophthalic acid copolymerized polyethylene terephthalate resin. A preferable copolymerization amount is 2 to 50 mol%, further 3 to 40 mol%, particularly 5 to 20 mol% in the total segment of (B-1) polyethylene terephthalate resin.

  The molecular weight of the polyethylene terephthalate resin is an intrinsic viscosity measured at 30 ° C. in a mixed solvent of phenol and tetrachloroethane (mass ratio = 50/50), preferably 0.5 to 1.8 dl / g. More preferably, it is 0.5-1.2 dl / g, and especially 0.6-0.9 dl / g is preferable. If the intrinsic viscosity is lower than 0.5 dl / g, the resulting resin composition tends to have a low mechanical strength. On the other hand, if it is higher than 1.2 dl / g, the fluidity of the resin composition may be deteriorated and the moldability may be deteriorated or the laser weldability may be deteriorated.

(B-2) Polycarbonate-based resin The polycarbonate-based resin may be a branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound or a small amount thereof with a phosgene or a carbonic acid diester. It is a coalescence. The production method of the polycarbonate-based resin is not particularly limited, and those produced by a conventionally known phosgene method (interfacial polymerization method) or melting method (transesterification method) can be used.

  As the raw material dihydroxy compound, an aromatic dihydroxy compound is preferable, 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, Hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc. are mentioned, Preferably bisphenol A is mentioned. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

  Among the polycarbonate-based resins, among the above-mentioned, aromatic polycarbonate resins derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other aromatics Aromatic polycarbonate copolymers derived from dihydroxy compounds are preferred. Further, it may be a copolymer mainly composed of an aromatic 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 polycarbonate resin mentioned above.

  In order to adjust the molecular weight of the polycarbonate-based resin, a monovalent aromatic hydroxy compound may be used. For example, m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-length Examples include chain alkyl-substituted phenols.

  The viscosity average molecular weight of the polycarbonate resin is preferably 5,000 to 30,000, and more preferably 5,000 to 20,000. If the viscosity average molecular weight is lower than 5,000, the resulting resin composition tends to have a low mechanical strength. If it is higher than 30,000, the fluidity of the resin composition may be deteriorated to deteriorate the moldability or the laser weldability may be lowered. The viscosity average molecular weight of the polycarbonate resin is a viscosity average molecular weight [Mv] converted from a solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent.

(B-3) Aromatic vinyl resin An aromatic vinyl resin is a polymer having an aromatic vinyl compound as a main component, and examples of the aromatic vinyl compound include styrene, α-methylstyrene, paramethylstyrene, vinyl. Toluene, vinyl xylene and the like can be mentioned, and styrene is preferable. Therefore, typical aromatic vinyl resins include polystyrene (PS), acrylonitrile-styrene (AS), methyl methacrylate-styrene (MS), styrene-maleic acid copolymer, and the like.

A rubber component can be copolymerized with the aromatic vinyl resin. Examples of the rubber component include conjugated diene hydrocarbons such as butadiene, isoprene and 1,3-pentadiene. When the rubber component is copolymerized, the amount of the rubber component to be copolymerized is 1% by mass or more and less than 50% by mass in the entire aromatic vinyl resin segment. The amount of the rubber component is preferably 3 to 40% by mass, and more preferably 5 to 30% by mass.
Rubber component copolymerized aromatic vinyl resins include rubber-modified polystyrene (HIPS), acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylic rubber copolymer, methyl methacrylate-butadiene-styrene (MBS), acrylonitrile- Examples thereof include styrene-acrylic acid (ASA), styrene-butadiene copolymer (SBS), and hydride thereof (SEBS), styrene-isoprene copolymer (SIS), and hydride thereof (SEPS).
Among aromatic vinyl resins, styrene resins such as PS, HIPS, AS, ABS, ASA, AES, MS, and MBS are particularly preferable from the viewpoint of physical properties.

  Examples of other copolymerizable monomers include α, β-unsaturated carboxylic acids such as acrylic acid and methacrylic acid, α, such as methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, and cyclohexyl methacrylate. α, β-unsaturated dicarboxylic acid anhydrides such as β-unsaturated carboxylic acid esters, maleic anhydride, itaconic anhydride, N-phenylmaleimide, N-methylmaleimide, Nt-butylmaleimide, α, Examples thereof include imide compounds of β-unsaturated dicarboxylic acid.

  The aromatic vinyl resin used in the present invention preferably has a weight average molecular weight of 50,000 to 500,000, more preferably 100,000 to 400,000, particularly 150,000 to 300,000. If the molecular weight is less than 50,000, bleeding out is observed in the molded product, or decomposition gas is generated during molding, and it is difficult to obtain sufficient weld strength. If the molecular weight is greater than 500,000, sufficient fluidity is obtained. It is difficult to improve the laser welding strength. When a resin having a weight average molecular weight lower than 50,000 is used, the resulting resin composition tends to have a low mechanical strength. When the viscosity is higher than 500,000, the fluidity of the resin composition is deteriorated and the moldability is deteriorated or the laser weldability is sometimes lowered. In addition, a weight average molecular weight says the value of polystyrene conversion by a gel permeation chromatography (GPC) method.

(B-4) Acrylic Resin The acrylic resin is preferably a (co) polymer containing a methyl methacrylate unit as a main component and containing 0 to 5% by mass of other acrylic ester units. The acrylic resin preferably has a weight average molecular weight in the range of 30,000 to 250,000. When a resin having a weight average molecular weight lower than 30,000 is used, the resulting resin composition tends to have a low mechanical strength. If it is higher than 250,000, the fluidity of the resin composition may be deteriorated and the moldability may be deteriorated or the laser weldability may be deteriorated. In addition, a weight average molecular weight says the value of polystyrene conversion by a gel permeation chromatography (GPC) method.

  The acrylic ester units that can be copolymerized with methyl methacrylate units are specifically methyl acrylate, ethyl acrylate, acrylic acid-n-butyl, acrylic acid-iso-butyl, acrylic acid-t-butyl. , Acrylic acid alkyl esters such as 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl cyclohexyl acrylate, bornyl acrylate, isobornyl acrylate, adamantyl acrylate, cycloalkyl acrylates, phenyl acrylate, acrylic acid Acrylic acid aromatic esters such as benzyl, acrylic acid-substituted aromatic esters such as fluorophenyl acrylate, chlorophenyl acrylate, fluorobenzyl acrylate, chlorobenzyl acrylate, and fluoromethacrylate Acrylic acid alkyl halide esters such as acrylic acid fluoroethyl, hydroxy alkyl acrylate, glycidyl acrylate, ethylene glycol ester and acrylic acid polyethylene glycol esters. These acrylic acid ester units can use 1 type (s) or 2 or more types. Of these, methyl acrylate is preferred.

(B-5) Polyamide resin Polyamide resins are obtained by polycondensation of lactam ring-opening polymers, polymers obtained by polycondensation of diaminocarboxylic acids, amines and dibasic acids or compounds equivalent thereto. It means the resulting polymers. Examples of the lactams include propiolactam, α-pyrrolidone, ε-caprolactam, enantolactam, ω-laurolactam, cyclododecalactam and the like, and examples of the diaminocarboxylic acid include aminocaproic acid, 7-aminoheptanoic acid, 11- Examples thereof include aminoundecanoic acid and 9-aminononanoic acid. Examples of amines include hexamethylenediamine, metaxylylenediamine, and paraxylylenediamine, and examples of dibasic acids include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanedioic acid, and glutaric acid. It is done.

More specifically, polyamide 4, polyamide 6, polyamide 7, polyamide 8, polyamide 11, polyamide 12, polyamide 66, polyamide 69, polyamide 610, polyamide 611, polyamide 612, polyamide 6T, polyamide 6/66, polyamide 6 / 12, polyamide 6 / 6T, polyamide 6I / 6T, polyamide MXD6 and the like.
The polyamide-based resin may be a single type or a mixture of two or more types. Among these, it is preferable that the melting point of the (A) polybutylene terephthalate resin is not so different, and aliphatic polyamides such as polyamide 6 and polyamide 66 are preferable.

  The polyamide resin preferably has a relative viscosity in the range of 2 to 5.5 measured in a 98% sulfuric acid at a concentration of 1% and a temperature of 25 ° C. in accordance with JIS K6810. When the relative viscosity is 2 or more, the mechanical properties are improved, and conversely, when it is 5.5 or less, the moldability and the laser weldability tend to be improved. A particularly preferable range of the relative viscosity is 2.2 to 4.5.

Content of above-mentioned (B-1)-(B-5) is 100 mass in total of (A) polybutylene terephthalate type-resin and (B) resin (resin of (B-1)-(B-5)). It is 5 to 50 parts by mass on the basis of parts, and (A) 95 to 50 parts by mass of the polybutylene terephthalate resin. (B) When the content of the resin is less than 5 parts by mass, the warp and laser weldability of the molded product are deteriorated, and when it exceeds 50 parts by mass, the moldability and chemical resistance are deteriorated. (B) Content of resin becomes like this. Preferably it is 10-50 mass parts, More preferably, it is 20-50 mass parts, Especially 20-40 mass parts is preferable.
In addition to the resin (A) and the resin (B), other resins can be contained. In this case, the content of the other resin is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, particularly preferably 10 parts by mass with respect to 100 parts by mass in total of the resin (A) and the resin (B). It is as follows.

[(D) Reinforcing filler]
The (D) reinforcing filler contained in the resin composition of the present invention has the effect of improving the mechanical properties of the resin composition obtained by blending with the resin, and is a usual inorganic filler for plastics. Can be used. Preferably, fibrous fillers such as glass fiber, carbon fiber, basalt fiber, wollastonite and potassium titanate fiber can be used. In addition, granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clays, organic clays, glass beads; plate-like fillers such as talc; scale-like fillers such as glass flakes, mica and graphite A material can also be used.
Of these, glass fibers are preferably used from the viewpoints of laser light permeability, mechanical strength, rigidity, and heat resistance.

  (D) It is more preferable to use a reinforcing filler that has been surface-treated with a surface treatment agent such as a coupling agent. The glass fiber to which the surface treatment agent is attached is preferable because it is excellent in durability, heat and humidity resistance, hydrolysis resistance, and heat shock resistance.

As the surface treatment agent, any conventionally known one can be used. Specifically, for example, silane coupling agents such as amino silane, epoxy silane, allyl silane, and vinyl silane are preferable.
Among these, aminosilane-based surface treatment agents are preferable, and specifically, for example, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ- (2-aminoethyl) aminopropyltrimethoxysilane are preferable. Take as an example.

Moreover, as a surface treating agent, epoxy resins, such as a novolac type, a bisphenol A type epoxy resin, etc. are mentioned preferably. Among these, novolac type epoxy resins are preferable.
The silane-based surface treatment agent and the epoxy resin may be used alone or in combination, and it is also preferable to use both in combination.

The glass fiber is preferably a glass fiber having an anisotropic cross-sectional shape in which the ratio of the major axis to the minor axis in the cross section is 1.5 to 10 from the viewpoint of laser weldability.
The cross-sectional shape is preferably one having a rectangular or oval cross section, and a major axis / minor axis ratio of 2.5 to 8, more preferably 3 to 6. When the major axis is D2, the minor axis is D1, and the average fiber length is L, the aspect ratio ((L × 2) / (D2 + D1)) is preferably 10 or more. When such flat glass fibers are used in this way, the warpage of the molded product is suppressed, which is particularly effective when manufacturing a box-shaped welded body.

  (D) Content of a reinforcement filler is 0-120 mass parts with respect to a total of 100 mass parts of (A) polybutylene terephthalate resin and (B) resin. (D) If the content of the reinforcing filler exceeds 120 parts by mass, the fluidity and laser weldability are lowered, which is not preferable. (D) The more preferable content of the reinforcing filler is 5 to 110 parts by mass, more preferably 15 to 100 parts by mass, still more preferably 30 to 100 parts by mass, and particularly preferably 40 to 100 parts by mass.

[(E) Epoxy compound]
The (E) epoxy compound preferably contained in the resin composition of the present invention functions to improve the laser weldability and heat-and-moisture resistance of the resin composition, and to further improve the strength and durability of the weld part of the molded product. To do. Accordingly, among the molded products made of the resin composition of the present invention, the molded product of the resin composition containing the epoxy compound is particularly suitable for use in places exposed to a wet heat state during use, such as automotive parts. is there.

(E) As an epoxy compound, what has one or more epoxy groups in one molecule should just be used, and usually a glycidyl compound which is a reaction product of alcohol, phenols, carboxylic acid, etc. and epichlorohydrin, A compound obtained by epoxidizing an olefinic double bond may be used.
(E) Preferred specific examples of the epoxy compound include, for example, bisphenol type epoxy compounds such as bisphenol A type epoxy compounds and bisphenol F type epoxy compounds, resorcin type epoxy compounds, novolac type epoxy compounds, alicyclic compound type diepoxy compounds, and glycidyl. Examples include ethers, glycidyl esters, and epoxidized polybutadiene. Examples of the alicyclic compound type epoxy compound include vinylcyclohexene dioxide and dicyclopentadiene oxide.

Specific examples of glycidyl ethers include monoglycidyl ethers such as methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether, and allyl glycidyl ether; Examples include pentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, and bisphenol A diglycidyl ether.
Examples of glycidyl esters include monoglycidyl esters such as benzoic acid glycidyl ester and sorbic acid glycidyl ester; adipic acid diglycidyl ester, terephthalic acid diglycidyl ester, and orthophthalic acid diglycidyl ester.

  Moreover, the (E) epoxy compound may be a copolymer having a glycidyl group-containing compound as one component. For example, a copolymer of a glycidyl ester of α, β-unsaturated acid and one or more monomers selected from the group consisting of α-olefin, acrylic acid, acrylic ester, methacrylic acid, and methacrylic ester Can be mentioned.

(E) The epoxy compound is preferably an epoxy compound having an epoxy equivalent of 100 to 500 g / eq and a number average molecular weight of 2,000 or less. When the epoxy equivalent is less than 100 g / eq, since the amount of the epoxy group is too large, the viscosity of the resin composition is increased, and the adhesiveness of the weld portion is likely to be reduced. On the contrary, when the epoxy equivalent exceeds 500 g / eq, the amount of the epoxy group decreases, and thus the effect of improving the heat and moisture resistance of the resin composition tends not to be sufficiently exhibited. When the number average molecular weight exceeds 2,000, the compatibility with the (A) thermoplastic polyester resin tends to decrease, and the mechanical strength of the molded product tends to decrease.
(E) As an epoxy compound, the bisphenol A type epoxy compound and novolak type epoxy compound obtained from the reaction of bisphenol A or novolak and epichlorohydrin are particularly preferable.

  The content of the (E) epoxy compound is 0 to 5 parts by mass with respect to a total of 100 parts by mass of the (A) polybutylene terephthalate resin and the (B) resin. It is preferable to contain more than part. If the content is more than 3 parts by mass, crosslinking may proceed and the fluidity at the time of molding may be deteriorated, so 0.2 to 3 parts by mass, particularly 0.2 to 2 parts by mass is preferable.

[(F) Flow modifier]
The (F) flow modifier preferably contained in the resin composition of the present invention includes styrene oligomers, olefin oligomers, acrylic oligomers, polyfunctional compounds, branched polymers (dendrimers (dendritic polymers), highly branched). Molds, hyperbranch types and cyclic oligomers) are preferably exemplified, and the fluidity is imparted and the mechanical strength is maintained. In particular, when producing a box-shaped welded body or a welded body having a flow length of 70 mm or more, the addition of (E) a flow modifier is effective.

(F-1) Styrene oligomer The styrene oligomer is a polymer mainly composed of a vinyl aromatic compound. Examples of the vinyl aromatic compound include styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, and vinylxylene. Styrene is preferable. Styrene oligomers include polystyrene, rubber-modified polystyrene, acrylonitrile-styrene, acrylonitrile-butadiene-styrene, methyl methacrylate-butadiene-styrene, acrylonitrile-acrylic acid-styrene, styrene-maleic acid copolymer, styrene-butadiene-styrene copolymer. Typical examples include polymer oligomers and hydrides thereof. Of these, styrene oligomers and acrylonitrile-styrene oligomers are particularly preferred from the viewpoint of physical properties and cost.
Styrene-based oligomers can also be obtained as commercial products. Examples of commercially available products include those manufactured by Toa Gosei Co., Ltd., trade name “Alfon (registered trademark) UP-1150”, manufactured by Yashara Chemical Co., Ltd., and trade name “YS Resin”. SX-100 "and the like are preferable.

  The styrene-based oligomer preferably has a relatively low weight average molecular weight, and specifically has a weight average molecular weight of 1,000 to 10,000, among which 1,500 to 7,500, particularly 2,000 to 6, 000 is preferred. If the molecular weight is less than 1,000, bleed out occurs in the molded product, or decomposition gas is generated during molding, making it difficult to obtain sufficient weld strength. On the other hand, if the molecular weight is greater than 10,000, it is difficult to improve sufficient fluidity and weld strength. In addition, a weight average molecular weight says the value of polystyrene conversion by a gel permeation chromatography (GPC) method.

  The content of the styrene-based oligomer is preferably 0.5 to 10 parts by mass, more preferably 2 to 10 parts by mass, and still more preferably with respect to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) resin. Is 3-7 parts by mass.

(F-2) Olefin-based oligomers Olefin-based oligomers are preferably those using α-olefins having 2 to 5 carbon atoms as monomer units, and ethylene and propylene are particularly preferable, and this is particularly useful with other copolymerization monomers. Polymerized oligomers are preferred.
As the copolymerization monomer, an acrylic monomer, particularly alkyl acrylate or alkyl methacrylate, is preferable, and examples thereof include methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate. Further, it may be end-modified with (anhydrous) maleic acid or the like.
Olefin-based oligomers can also be obtained as commercial products. Examples of commercially available products include those manufactured by Arkema Co., Ltd., trade names “Rotril (registered trademark) 37EH550”, “35BA320”, Nippon Unicar Company Limited, trade names “ NUC-6070 "etc. are mentioned preferably.

The olefin-based oligomer preferably has a polystyrene-equivalent weight average molecular weight of about 2,000 to 20,000 as measured by GPC, and more preferably 3,000 to 15,000, particularly 5,000 to 15,000. If the molecular weight is less than 2,000, bleed out occurs in the molded product, or decomposition gas is generated during molding, making it difficult to obtain sufficient weld strength. On the other hand, when the molecular weight is larger than 20,000, it is difficult to improve sufficient fluidity and weld strength.
In addition, the melt flow rate (MFR) of the olefin oligomer is preferably 50 g / 10 min or more, and more preferably 100 g / 10 min or more. If the MFR is less than 50 g / 10 min, the laser weldability tends to decrease. The MFR of the olefin oligomer is a value measured under conditions of a temperature of 190 ° C. and a load of 2.16 kg.
The content of the olefin oligomer is preferably 0.5 to 10 parts by mass, more preferably 2 to 10 parts by mass, and still more preferably, with respect to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) resin. Is 3-7 parts by mass.

(F-3) Acrylic oligomer The acrylic oligomer is preferably an acrylic or methacrylic alkyl oligomer. Such a polymer of acrylic acid or methacrylic acid alkyl ester may be other vinyl monomer, for example, α-olefin such as ethylene, propylene, butene-1, styrene, acrylonitrile, vinyl acetate, butadiene, vinyl alcohol, malee. It may contain monomer units such as acid, fumaric acid, itaconic acid or esters thereof.
Acrylic oligomers can also be obtained as commercial products. Examples of commercially available products include those manufactured by Toa Gosei Co., Ltd., trade names “Alfon (registered trademark) UP-1050”, “UH-2032”, and Soken Chemical Co., Ltd. Product names “UMB-1001”, “UMB-2005”, “UT-2001”, manufactured by ADEKA, product names “ADK STAB (registered trademark) FC-112”, “FC-113”, “LS-3” The product name “METABRENE (registered trademark) L1000” manufactured by Mitsubishi Rayon Co., Ltd. is preferred.

  The acrylic oligomer preferably has a polystyrene-equivalent weight average molecular weight of about 1,000 to 10,000 as measured by GPC measurement, and particularly preferably 1,500 to 7,500, particularly 2,000 to 6,000. If the molecular weight is less than 1,000, bleed out occurs in the molded product, or decomposition gas is generated during molding, making it difficult to obtain sufficient weld strength. On the other hand, if the molecular weight is greater than 10,000, it is difficult to improve sufficient fluidity and weld strength.

  The content of the acrylic oligomer is preferably 0.5 to 10 parts by mass, more preferably 2 to 10 parts by mass, and still more preferably, with respect to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) resin. Is 3-7 parts by mass. If the content is less than 0.5 parts by mass, the effect of improving the fluidity is small, and if it exceeds 10 parts by mass, melt kneading becomes difficult, and even if kneading is possible, bleeding and gas generation during molding are likely to occur. There is a risk that dirt will adhere to the surface.

(F-4) Polyfunctional compound The polyfunctional compound is preferably a compound having three or more functional groups, and more preferably a polyhydric alcohol compound having three or more hydroxyl groups. Examples of polyhydric alcohol compounds having three or more hydroxyl groups include 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,6- Hexanetetrol, glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, triethanolamine, trimethylolethane, trimethylolpropane, ditrimethylolpropane, tritrimethylolpropane, 2-methylpropanetriol, 2-methyl -1,2,4-butanetriol, pentaerythritol, dipentaerythritol, tripentaerythritol, methylglucoside, sorbitol, mannitol, sucrose, 1,3,5-trihydroxybenzene, 1,2,4-trihydroxy Benzene, (poly) oxyethylene glycerol, (poly) oxypropylene glycerol, (poly) oxyethylene diglycerol, (poly) oxypropylene diglycerol, (poly) oxyethylene trimethylolpropane, (poly) oxypropylene trimethylolpropane, (Poly) oxyethylene ditrimethylolpropane, (poly) oxypropylene ditrimethylolpropane, (poly) oxyethylene pentaerythritol, (poly) oxypropylene pentaerythritol, (poly) oxyethylene dipentaerythritol, (poly) oxypropylene dipenta Examples include erythritol. Of these, pentaerythritol, trimethylolpropane, ditrimethylolpropane, and dipentaerythritol are preferable.

  As a preferred example of a compound having three or more functional groups, when the functional group is a carboxyl group, propane-1,2,3-tricarboxylic acid, 2-methylpropane-1,2,3-triscarboxylic acid, butane -1,2,4-tricarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, trimellitic acid, trimesic acid, hemimellitic acid, pyromellitic acid, benzenepentacarboxylic acid, cyclohexane-1,2, 4-tricarboxylic acid, cyclohexane-1,3,5-tricarboxylic acid, cyclohexane-1,2,4,5-tetracarboxylic acid, naphthalene-1,2,4-tricarboxylic acid, naphthalene-2,5,7-tricarboxylic acid Acid, pyridine-2,4,6-tricarboxylic acid, naphthalene-1,2,7,8-tetracarboxylic acid, naphthalene-1,4,5,8- Polycarboxylic acid or acrylic acid, such as tetracarboxylic acid, include polymers such as methacrylic acid, it may be used acid anhydrides thereof. Of these, propane-1,2,3-tricarboxylic acid, trimellitic acid, trimesic acid and acid anhydrides having a branched structure are preferable from the viewpoint of fluidity.

  The content of the polyfunctional compound is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, with respect to a total of 100 parts by mass of the (A) polybutylene terephthalate resin and the (B) resin. More preferably, it is 0.2-3 mass parts.

(F-5) Branched polymer A branched polymer can also be used as the flow modifier (F). A branched polymer refers to a polymer having a branched structure, and specifically refers to a polymer having a multi-branched structure. As the branched structure, a plurality of linear segments are radially branched from a central core. A star polymer, a graft polymer having a structure in which a polymer having a number of branch points is introduced into a main linear polymer chain and from which a branch polymer is introduced, and has a three-dimensional branching and branching into repeating units Examples include hyperbranched polymers having a structure, and dendrimers with a precisely controlled molecular weight distribution and degree of branching. Star polymers and hyperbranched polymers are preferable. From the viewpoint of fluidity, hyperbranched polymers are more preferable. To hyperbranched polymers are preferred.
Examples of such branched polymers include polyester-based or polyurethane-based branched polymers. Examples of commercially available hyperbranched polymers include “Borton (registered trademark)” by Perstorp.

  The content of the branched polymer is preferably 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, with respect to 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) resin. More preferably, it is 0.2-3 mass parts.

  The content of these (F) flow modifiers is 0 to 10 parts by mass with respect to a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) resin. It is preferable to contain 0.1 part by mass or more. If the content is more than 10 parts by mass, the mechanical properties may be deteriorated, so 0.2 to 10 parts by mass, particularly 0.3 to 7 parts by mass is particularly preferable.

[(G) Laser light absorbing dye]
The resin composition of the present invention contains 0.001 to 0.2 parts by mass of (G) a laser light absorbing dye with respect to a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) resin. .
And (G) one or more laser light absorptions selected from nigrosine, aniline black, phthalocyanine, naphthalocyanine, porphyrin, perylene, quaterylene, azo dye, anthraquinone, squaric acid derivative and immonium Sex dyes are used.

Of these, a particularly preferred laser-absorbing dye is nigrosine.
Nigrosine is C.I. I. SOLVENT BLACK 5 and C.I. I. It is a black azine-based condensation mixture as described in COLORINDEX as SOLVENT BLACK 7. This can be synthesized, for example, by oxidizing and dehydrating aniline, aniline hydrochloride and nitrobenzene at a reaction temperature of 160 to 180 ° C. in the presence of iron chloride.
Examples of commercially available nigrosine (B) include “NUBIAN (registered trademark) BLACK” (trade name, manufactured by Orient Chemical Industry Co., Ltd.).

  The content of the (G) laser light-absorbing dye is 0.001 to 0.2 parts by mass with respect to a total of 100 parts by mass of the (A) polybutylene terephthalate resin and the (B) resin, and preferably is 0.00. It is 003-0.1 mass part, More preferably, it is 0.005-0.05 mass part. By adjusting the content of the laser light absorbing dye within such a range, the converted absorbance of the resin composition for laser welding can be set to 0.2 to 2.

  Moreover, the other absorptive dye with respect to a laser beam, an absorber, or a coloring agent may be included. By containing other absorptive dyes, absorbents or colorants, it is also possible to adjust the converted absorbance of the resin composition for laser welding. As the colorant, carbon black is particularly preferable.

[(H) Impact modifier]
The resin composition of the present invention may contain (H) an impact resistance improver for the purpose of improving impact resistance and heat shock resistance. (H) The impact resistance improver is not particularly limited as long as it has an effect of improving the impact resistance of the resin, but is not limited to polyester elastomer, styrene elastomer, polyolefin elastomer, diene elastomer, acrylic elastomer, Known materials such as polyamide-based elastomers, polyurethane-based elastomers, fluorine-based elastomers, silicone-based elastomers, acrylic core / shell type elastomers, and the like are preferable, and polyester-based elastomers and styrene-based elastomers are preferable.

  The polyester elastomer is a thermoplastic polyester having rubber properties at room temperature, preferably a thermoplastic elastomer mainly composed of a polyester block copolymer, and has a high melting point and high crystallinity as a hard segment. A block copolymer having an amorphous polyester or an amorphous polyether as a soft segment is preferable. The content of the soft segment of the polyester-based elastomer is at least 20 to 95 mol% in all segments, and 50 to 50 in the case of a block copolymer of polybutylene terephthalate and polytetramethylene glycol (PTMG-PBT copolymer). 95 mol%. The content of the preferred soft segment is 50 to 90 mol%, particularly 60 to 85 mol%. Among them, a polyester ether block copolymer, particularly a PTMG-PBT copolymer, is preferable because a decrease in transmittance is reduced.

  Specific examples of polyester elastomers include “Primalloy” (trade name, registered trademark (hereinafter the same)) manufactured by Mitsubishi Chemical Corporation, “Perprene” (manufactured by Toyobo), “Hytrel” (manufactured by Toray DuPont), “ “Byron” (manufactured by Toyobo Co., Ltd.), “Polyester” (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like are preferred.

Moreover, a styrene-type elastomer means what consists of a styrene component and an elastomer component, and contains 50-90 mass% of elastomer components. The elastomer component is preferably contained in a proportion of 55 to 85% by mass, more preferably 60 to 80% by mass. Examples of the elastomer component in this case include conjugated diene hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene. More specifically, a copolymer of styrene and butadiene (SBS) elastomer, styrene and Examples thereof include a copolymer (SIS) elastomer with isoprene.
It is also preferable to use a resin (SEBS, SEPS) obtained by hydrogenating the above SBS elastomer or SIS elastomer.

  Specific examples of styrene elastomers include “Dynalon” (manufactured by JSR, trade name and registered trademark (hereinafter the same)), “Tuftec” (manufactured by Asahi Kasei Chemicals), “Hibler”, “Septon” (manufactured by Kuraray) Etc.

As the (H) impact resistance improver, a copolymer-type elastomer containing an epoxy group is also preferable because it has good reactivity with the (A) polybutylene terephthalate resin and there is little decrease in laser transmittance.
The type of copolymer elastomer containing an epoxy group is not limited. For example, those obtained by introducing an epoxy group into the above-described styrene elastomer, olefin elastomer using polyolefin, acrylic elastomer and the like are preferable. For example, in the case of a styrene-butadiene copolymer obtained by copolymerizing polystyrene as a hard segment and butadiene as a soft segment, an epoxy group-containing elastomer can be obtained by epoxidizing an unsaturated double bond portion of a diene component.
In addition, the olefin elastomer may have a polyolefin part in the soft phase, and EPR, EPDM, etc. can be preferably used.
The method for introducing an epoxy group is not particularly limited, and it may be incorporated into the main chain, or a polymer containing an epoxy group may be introduced into the olefin elastomer in a block or graft form. Preferably, a (co) polymer having an epoxy group is introduced in a graft form.

  Specific examples of copolymer-type elastomers containing epoxy groups include “Bond First” (trade name, registered trademark (hereinafter the same)) manufactured by Sumitomo Chemical Co., Ltd., “Rotada” (manufactured by Arkema), “Elvalloy” (Mitsui DuPont Polychemical Co., Ltd., “Paraloid” (Rohm and Haas Co., Ltd.), “Metabrene” (Mitsubishi Rayon Co., Ltd.), “Epofriend” (Daicel Chemical Industries Co., Ltd.), and the like.

  (H) The impact resistance improver may be used alone or in combination of two or more. The content of (H) impact modifier is usually 0 to 20 parts by mass, preferably 1 to 18 parts by mass, more preferably 100 parts by mass in total of (A) polybutylene terephthalate resin and (B) resin. Is 2 to 15 parts by mass, more preferably 3 to 12 parts by mass, and particularly preferably 3 to 7 parts by mass. (H) When the content of the impact resistance improver exceeds 20 parts by mass, the heat resistance rigidity tends to decrease.

[Other ingredients]
The resin composition of the present invention may contain various additives as long as the effects of the present invention are not impaired. Examples of such additives include stabilizers, release agents, ultraviolet absorbers, antistatic agents, antifogging agents, lubricants, antiblocking agents, plasticizers, dispersants, antibacterial agents, and the like.

<Stabilizer>
It is preferable that the resin composition of the present invention further contains a stabilizer in that it has effects of improving thermal stability and preventing deterioration of mechanical strength, transparency and hue. As the stabilizer, a phosphorus stabilizer, a sulfur stabilizer and a phenol stabilizer are preferable.

  Examples of the phosphorus-based stabilizer include phosphorous acid, phosphoric acid, phosphite ester, and phosphate ester. Among them, organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds are preferable.

The organic phosphate compound is preferably the following general formula:
(R ¹ O) _3-n P (═O) OH _n (1)
(In Formula (1), R ¹ is an alkyl group or an aryl group, and may be the same or different. N represents an integer of 0 to 2.)
It is a compound represented by these. More preferably, R ¹ is a long-chain alkyl acid phosphate compound having 8 to 30 carbon atoms. Specific examples of the alkyl group having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, A hexadecyl group, an octadecyl group, an eicosyl group, a triacontyl group, etc. are mentioned.

  Examples of the long-chain alkyl acid phosphate include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonyl phenyl acid phosphate Acid phosphate, phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, geo Chill acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and a bis-nonylphenyl acid phosphate, or the like. Among these, octadecyl acid phosphate is preferable, and this is marketed under the trade name “ADEKA STAB AX-71” of ADEKA.

As the organic phosphite compound, preferably, the following general formula:
^{R 2 O-P (OR 3} ) (OR 4) ··· (2)
(In the formula ^(2), R 2, ^{R 3} and ^{R 4} are each a hydrogen atom, an alkyl group or an aryl group having 6 to 30 carbon atoms carbon atoms 1 to ^30, R 2, ^{R 3} and R ⁴ is an aryl group having 6 to 30 carbon atoms.
The compound represented by these is mentioned.

  Examples of the organic phosphite compound include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite Hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-t rt-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4′-isopropylidenediphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, di Lauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite Phytopolymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphite, 2,2'-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite and the like. Among these, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferable.

The organic phosphonite compound is preferably the following general formula:
R ⁵ -P (OR ⁶ ) (OR ⁷ ) (3)
(In the formula ^(3), R 5, ^{R 6} and ^{R 7} are each a hydrogen atom, an alkyl group or an aryl group having 6 to 30 carbon atoms carbon atoms 1 to ^30, R 5, ^{R 6} and R ^At least one of ⁷ is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

  Examples of the organic phosphonite compound include tetrakis (2,4-di-iso-propylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-n-butylphenyl) -4,4′-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylene diphospho Knight, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrakis (2,6-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2, -Di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, and tetrakis (2,6- And di-tert-butylphenyl) -3,3′-biphenylenediphosphonite.

  As the sulfur stabilizer, any conventionally known sulfur atom-containing compound can be used, and among these, thioethers are preferred. Specifically, 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 isopropylxanthate, trilauryltrithiophosphite. Among these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferable.

  Examples of the phenol-based stabilizer include pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-tert-butyl-4) -Hydroxyphenyl) propionate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), pentaerythritol tetrakis (3- (3,5-di-neopentyl-4-hydroxyphenyl) ) Propionate) and the like. Among these, pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate is preferred.

  One type of stabilizer may be contained, or two or more types may be contained in any combination and ratio.

  The content of the stabilizer is preferably 0.001 to 1 part by mass with respect to 100 parts by mass in total of the (A) polybutylene terephthalate resin and the (B) resin. When the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect an improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and a deterioration in hue during molding are likely to occur. When it exceeds, it will become excess amount and there exists a tendency for generation | occurrence | production of silver and a hue deterioration to occur further easily. The content of the stabilizer is more preferably 0.001 to 0.7 parts by mass, and still more preferably 0.005 to 0.5 parts by mass.

<Release agent>
The resin composition of the present invention preferably further contains a release agent. As the mold release agent, known mold release agents usually used for polyester resins can be used. Among them, one or more mold release agents selected from polyolefin compounds, fatty acid ester compounds, and silicone compounds are used. preferable.

  Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax. Among them, those having a mass average molecular weight of 700 to 10,000, more preferably 900 to 8,000 are preferable. In addition, modified polyolefin compounds in which a hydroxyl group, a carboxyl group, a hydroxyl group, an epoxy group, or the like is introduced into the side chain are also particularly preferable.

  Examples of the fatty acid ester compounds include fatty acid esters such as glycerin fatty acid esters, sorbitan fatty acid esters, pentaerythritol fatty acid esters, and partially saponified products thereof. Among them, carbon atoms are 11 to 28, preferably carbon atoms. Fatty acid esters composed of fatty acids of several 17 to 21 are preferred. Specific examples include glycerol monostearate, glycerol monobehenate, glycerol dibehenate, glycerol-12-hydroxy monostearate, sorbitan monobehenate, pentaerythritol distearate, pentaerythritol tetrastearate and the like.

  Moreover, as a silicone type compound, the compound modified | denatured from points, such as compatibility with a polyester resin, is preferable. Examples of the modified silicone oil include silicone oil in which an organic group is introduced into the side chain of polysiloxane, silicone oil in which an organic group is introduced into both ends and / or one end of polysiloxane, and the like. Examples of the organic group to be introduced include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacryl group, a mercapto group, and a phenol group, and preferably an epoxy group. As the modified silicone oil, a silicone oil in which an epoxy group is introduced into the side chain of polysiloxane is particularly preferable.

  It is preferable that content of a mold release agent is 0.05-2 mass parts with respect to a total of 100 mass parts of (A) polybutylene terephthalate resin and (B) resin. If the amount is less than 0.05 parts by mass, the surface property tends to decrease due to defective mold release at the time of melt molding. On the other hand, if it exceeds 2 parts by mass, the kneading workability of the resin composition decreases, and molding is also performed. The surface of the product may be cloudy. The content of the release agent is preferably 0.07 to 1.5 parts by mass, more preferably 0.1 to 1.0 parts by mass.

  The resin composition of the present invention can contain (A) a polybutylene terephthalate resin and (B) a thermoplastic resin other than the resin as long as the effects of the present invention are not impaired. Specific examples of the other thermoplastic resins include polysulfone resins, polyether sulfone resins, polyetherimide resins, polyether ketone resins, and polyphenylene ether resins.

[Method for Producing Resin Composition]
As a manufacturing method of the resin composition of this invention, it can carry out in accordance with the conventional method of resin composition preparation. Usually, the components and various additives added as desired are mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Moreover, it is also possible to prepare the resin composition of the present invention by mixing each component in advance or by mixing only a part of the components in advance and supplying them to an extruder using a feeder and melt-kneading them. Further, (A) a polybutylene terephthalate resin or (B) a part of the resin blended with a part of other components is melt-kneaded to prepare a masterbatch, and then the remaining other ingredients are added thereto. You may mix | blend and melt-knead.
In addition, when using fibrous reinforcement fillers, such as glass fiber, it is also preferable to supply from the side feeder in the middle of the cylinder of an extruder.

  The heating temperature at the time of melt kneading can be appropriately selected from the range of usually 220 to 300 ° C. If the temperature is too high, decomposition gas is likely to be generated, which may cause opacity. Therefore, it is desirable to select a screw configuration in consideration of shear heat generation. In order to suppress decomposition during kneading or molding in the subsequent process, it is desirable to use an antioxidant or a heat stabilizer.

[Laser welded compact]
The manufacturing method of a molded object is not specifically limited, The molding method generally employ | adopted about the polyester resin composition can be employ | adopted arbitrarily. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include a blow molding method. Of these, injection molding is preferred.

The resin composition for laser welding of the present invention is characterized in that its converted absorbance a is adjusted to be in the range of 0.2-2. Here, the converted absorbance a is defined as the absorbance with respect to laser light having a wavelength of 940 nm, which is converted into a 1 mm thickness of the molded product.
The molded product obtained by molding the laser welding resin composition of the present invention has a converted absorbance a in the range of 0.2 to 2 (in terms of 1 mm thickness), preferably 0.2 to 1, particularly 0.3 to 0.8. Since this balances the transmission and absorption of laser light, there are two types of molded products made of laser light-transmitting resin and molded products made of laser light-absorbing resin, as in conventional laser welding. It is not necessary to use it, and it becomes possible to provide a polyester-based laser-welded molded body that can be laser-welded with only one type of resin material. In particular, the effect of the present invention is remarkable when welding welds made of the same kind of resin material are welded together.
The shape or the like of the laser welded molded body is arbitrary, and may be a deformed extruded product (bar, pipe, etc.) that is subjected to end-to-end welding for welding, and a current-carrying part that requires high waterproofness and airtightness. A metal-inserted molded product used for parts and the like is also preferable.

[Laser welding]
In the laser welding resin composition of the present invention, the converted absorbance a is suppressed to a low range of 0.2-2. For this reason, as described above, it is not necessary to use two types of a molded body made of a laser light-transmitting resin and a molded body made of a laser light-absorbing resin, and the laser light has a large penetration depth, and therefore a large melting temperature. Since the depth can be ensured, sufficiently high welding strength can be achieved not only by superposition welding but also by butt welding of the end portions of the laser welding molded body, which has not been possible until now. In addition, even when a gap is generated in the joining portion due to sink marks or warpage during molding, the gap is 0.1 mm or more, preferably 0.2 mm or more, more preferably 0.5 mm or more, particularly 1 mm. Even in the above case, laser welding is possible.
The type of laser light to be irradiated is arbitrary as long as it is near infrared laser light, such as YAG (yttrium, aluminum, garnet crystal) laser (wavelength 1064 nm), LD (laser diode) laser (wavelength 808 nm, 840 nm, 940 nm), etc. Can be preferably used.

[Laser welded body]
The shape, size, thickness, etc. of the welded body that has been laser-welded are arbitrary. Applications of the welded body include parts for transportation equipment such as automobiles, parts for electrical and electronic equipment, parts for industrial machinery, and other consumer parts. Particularly preferred.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited to the following examples.

In the following Examples and Comparative Examples, the components used are as shown in Table 1 below.
Glass fibers (D-3) and (D-4) were produced as follows.
The glass fiber to which the amino-based silane and the novolac-type epoxy resin are adhered is 4 mass% of phenol novolac-type epoxy resin and 1 mass of γ-aminopropyltriethoxysilane in accordance with the method described in Example 1 of JP-A-2001-172055. %, A sizing agent comprising 2% by mass of urethane emulsion and 93% by mass of deionized water was prepared and then applied to the glass fiber strand. This strand was cut into 3 mm. The amount of sizing agent attached to the obtained glass fiber chopped strands was 0.7% by mass. The glass fiber thus obtained is a glass fiber (D-3), and a glass fiber (D-4) is obtained by using a bisphenol A type epoxy resin instead of a phenol novolac type epoxy resin.

(Examples 1-39 [However, Examples 9-16, 18, 26-27 are reference examples] , Comparative Examples 1-9)
An injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., Nestal SG75-SYCAP-M3A) using a resin composition in which the components described in Table 1 are blended in the amounts (parts by mass) described in Table 2 and below. Were used, and injection molded at a cylinder temperature of 255 ° C. to produce molded products # 1 to # 5 described below.
Using the obtained molded articles # 1 to # 5, the following tests were performed.
Laser welding uses a laser device “L10060” manufactured by Hamamatsu Photonics Co., Ltd., laser wavelength: 940 nm, laser scanning speed: 1 mm / second, and laser output of 5 W, 10 W, 20 W for each Example and each Comparative Example. It changed with 30W, 40W, and 50W, and performed by selecting the output from which the maximum welding strength was obtained.

<Measurement method of converted absorbance>
At the welded part of molded product # 1, transmittance T (%) and reflectance R (%) at a wavelength of 940 nm were determined by detection with an integrating sphere using “UV-3100PC” manufactured by Shimadzu Corporation. Further, the absorbance a is obtained by the formula a = −log {T / (100−R)}, and the converted absorbance converted to 1 mm thickness is obtained as a / t using the thickness t (mm) of the measurement part. It was.

<Weld strength and test of molded product # 1 and molded product # 2>
・ Molded product # 1 and molded product # 2:
As molded product # 1 and molded product # 2, ASTM No. 4 dumbbell (1.5 mmt) was used.
・ Weld strength:
As shown in FIG. 1, the molded product # 1 and the molded product # 2 are shifted and overlapped, and the overlapping portion is irradiated with laser light from the molded product # 1 side to be welded. The tip of each was gripped, and the load causing shear fracture by applying a load in the pulling direction was determined. As the tensile tester, “5544” manufactured by Instron was used, and the tensile speed was 5 mm / min (the same applies hereinafter).
・ Gap welding strength:
At the time of welding, welding is performed by sandwiching metal piece spacers on both sides of the welded part of molded product # 1 and molded product # 2, and the gap interval is changed to 0.2 mm, 0.3 mm, 0.5 mm, 1.0 mm, and the above Similarly, the tensile shear fracture load was determined.
-Butt welding strength:
As shown in FIG. 2, the tabs of the molded product # 1 and the molded product # 2 are abutted and welded by irradiating the mating portion with a laser beam, and then opposite to the welded portions of the molded product # 1 and the molded product # 2. Each of these was grasped, and a load to break by applying a load in the pulling direction was obtained under the same conditions as described above.

<Welding and welding strength test of molded product # 3 and molded product # 4>
Plate-shaped molded product # 3 (100 mm × 100 mm × 1.5 mm thickness) having the shape shown in FIG. 3 and box-shaped molded product # 4 (80 mm × 80 mm × height 20 mm, thickness 3 mm) having the shape shown in FIG. After irradiating laser light from the plate-shaped molded product # 3 side and welding along the edge of the upper opening of the box-shaped molded product # 4, a hole of Φ10mm is made in the center of the bottom of the box by drilling A composite molded body was prepared. The internal pressure was applied from the hole of the composite molded body in water, and the maximum value of the internal pressure at which a part of the welded portion was broken and bubbles were generated was determined. It can be said that the greater the maximum value of the internal pressure, the higher the welding strength.

<Moldability evaluation of molded product # 4>
When the box-shaped molded article # 4 of FIG. 4 was injection-molded at a cylinder temperature of 255 ° C. and a mold temperature of 80 ° C., the presence or absence of protruding traces appearing on the opposite side of the ejector pin contact portion was confirmed. The case where there was no protruding trace was indicated by ◯, the case where a slight protruding trace was observed was indicated by Δ, and the case where the protruding trace was observed remarkably was indicated by ×. It can be said that molding is possible at a high cycle and the moldability is excellent so that no protruding trace is seen.

<Tensile strength test of molded product # 5>
As the molded product # 5, an ISO multipurpose test dumbbell (4 mm thick) was used, and measurement was performed in accordance with ISO527-1, 527-2.

The above evaluation results are shown in Tables 2 to 7 below.
“X” in the table indicates that laser welding could not be performed. The value with “*” in the butt welding strength was obtained by shifting the laser irradiation position by 1 mm toward the molded product # 1 side in order to obtain optimum welding conditions. “Real” represents an example, “Ratio” represents a comparative example, and “Part” represents part by mass.

  The resin composition for laser welding of the present invention is excellent in moldability and has extremely excellent laser welding processability. Therefore, since the resin composition of the present invention can be particularly suitably applied to the production of various parts such as automobile parts and electric / electronic equipment parts by laser welding, there are some industrial applicability.

Claims (11)

A resin composition used for welding by laser light,
(A) polybutylene terephthalate resin, and (B) ( B-1) at least one resin selected from polyethylene terephthalate resin or (B- 2 ) polycarbonate resin, a total of 100 of (A) and (B) On the basis of parts by mass, (A) 50 to 95 parts by mass, (B) 50 to 5 parts by mass,
Furthermore, for a total of 100 parts by mass of (A) and (B),
(D) 0 to 120 parts by mass of reinforcing filler, (E) 0 to 5 parts by mass of epoxy compound, (F) 0 to 10 parts by mass of flow modifier, and (G) nigrosine, aniline black, phthalocyanine the naphthalocyanine and anthraquinone or al least one laser ray absorbing dye selected containing 0.001 to 0.2 parts by weight,
A laser-welded resin composition having a converted absorbance a (absorbed with respect to laser light having a wavelength of 940 nm, converted to 1 mm thickness) of 0.2 to 2. (A) The resin composition for laser welding according to claim 1, wherein the polybutylene terephthalate resin has an intrinsic viscosity of 0.5 to 2 dl / g. (B-1) The laser welding resin composition according to claim 1 or 2, wherein the polyethylene terephthalate resin has an intrinsic viscosity of 0.5 to 1.8 dl / g. (B-2) The resin composition for laser welding according to any one of claims 1 to 3, wherein the polycarbonate resin has a viscosity average molecular weight of 5,000 to 30,000. (A) The polybutylene terephthalate resin is a polybutylene terephthalate copolymer obtained by copolymerizing a polybutylene terephthalate homopolymer and / or isophthalic acid and / or a polyalkylene glycol . The resin composition for laser welding as described in 1. (D) The reinforcing filler is a glass fiber having an anisotropic cross-sectional shape in which a ratio of a major axis to a minor axis in a cross-section is 1.5 to 10, according to any one of claims 1 to 5 . Laser welding resin composition. (F) The laser welding according to any one of claims 1 to 6 , wherein the flow modifier is at least one selected from the following (F-1) to (F-4). Resin composition.
(F-1) Styrene oligomer (F-2) Olefin oligomer (F-3) Acrylic oligomer (F-4) Polyfunctional compound A molded article for laser welding formed by molding the resin composition for laser welding according to any one of claims 1 to 7 . A laser welded body laser welded using the molded body according to claim 8 . The laser welded body according to claim 9 , wherein a gap between the formed bodies when the welded body is welded is at least 0.1 mm in at least a part of the welded portion. The laser welded body according to claim 9 or 10 , wherein the ends of the molded body are butted against each other.

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