JP4565958B2 - Laser welding resin composition and molded product - Google Patents

Description

  The present invention relates to a polybutylene terephthalate resin composition having high laser weldability and excellent molding processability and / or alkali resistance, and a molded article using the same.

  Polybutylene terephthalate (PBT) resin is excellent in various properties such as heat resistance, chemical resistance, electrical properties, mechanical properties, and molding processability.・ It is used for a wide range of applications including electronic devices. Specific applications include various automotive electrical parts (various control units, various sensors, ignition coils, etc.), connectors, switch parts, relay parts, coil parts, and the like. In some cases, airtightness is required for these parts, and in order to easily manufacture such parts, bonding methods such as an adhesive, hot plate welding, and ultrasonic welding are used. However, some problems have been pointed out regarding these joining methods. For example, when an adhesive is used, a process time loss until the adhesive is cured and an environmental load become a problem. In hot plate welding and ultrasonic welding, there is a concern about product damage due to heat or vibration.

  On the other hand, the joining method by laser welding does not damage the product due to heat and vibration accompanying welding, and the welding process is very simple. However, it has been pointed out that when a PBT resin is bonded by laser welding, the laser beam is lowly transmitted, so that carbonization or the like occurs and the welding cannot be substantially performed. Japanese Patent Laid-Open No. 2001-26656 (Patent Document 1) manufactures a molded product by integrating a molded product formed of a polyester copolymer having a melting point within a specific range and another molded product by welding. A method is disclosed. This document describes that homopolyalkylene arylate resins (polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate) have low laser welding strength.

  In JP-A-10-245481 (Patent Document 2), a composition composed of a thermoplastic polycarbonate resin and a thermoplastic polyester resin such as polyethylene terephthalate is mixed with methacrylic acid in the presence of a cross-linked acrylic ester elastic body. A thermoplastic resin composition containing 1 to 10% by weight of a methacrylic ester resin (graft resin) obtained by graft polymerization of a monomer having an ester as a main component is disclosed. This document describes an example in which a bisphenol A type polycarbonate resin and a polyethylene terephthalate resin are used in a ratio of 1.5 / 1 to 4/1 (weight ratio) in the resin composition. Furthermore, a hot plate welding method, a vibration welding method, or an ultrasonic welding method is also described as a thermal welding method for the composition. However, this composition requires the graft resin in order to increase the welding strength, and when this graft resin is used, mechanical strength, heat resistance, and the like are liable to decrease.

  Furthermore, depending on the part, the transmittance for the laser beam may vary depending on the molded product based on the PBT resin. For this reason, when such a molded product is laser-welded to a counterpart material (resin molded product), the molded product and the molded product as the counterpart material may not be welded uniformly and firmly at the contact interface.

  In addition, PBT-based resins have relatively low long-term durability against alkaline solutions, and use environments and uses are limited. For example, depending on the use of the resin molded product, it may be used in contact with chemicals such as a toilet cleaner, a bathroom cleaner, a bleaching agent, and a snow melting agent. And such a chemical | medical agent contains sodium hydroxide, sodium hypochlorite, sodium percarbonate, calcium chloride etc. as a structural component. Therefore, the resin molded product is exposed to an alkaline atmosphere (in some cases, frequently repeated). In particular, if the resin molded product is excessively strained by screw tightening, metal press-fitting, caulking, etc., and exposed to an alkali atmosphere as described above for a long time or frequently, both the strain and the alkali component As a result, so-called environmental stress cracking occurs and cracks occur in the molded product.

  On the other hand, insert molding is used in a wide range of fields for integral molding of a resin composition and a member made of a non-resin material such as a metal or an inorganic solid. It is possible to obtain a composite molded article that takes advantage of both characteristics of the resin-based material. For example, specific uses of the insert-molded product include various automotive electrical components (various control units, various sensors, ignition coils, etc.), connectors, switch components, coil components, and the like. However, since the shrinkage rate and the linear expansion coefficient are different between the resin composition and a non-resin material such as a metal, distortion occurs around the non-resin material. When the composite molded product thus distorted is exposed to the above alkaline atmosphere for a long period of time, cracks occur around the non-resin material such as metal.

  Therefore, PBT resin compositions with improved alkali resistance are also being studied. JP-A-2002-356611 (Patent Document 3) discloses a polybutylene terephthalate-based resin (A) containing 30 to 95 parts by weight of a polybutylene terephthalate / isophthalate copolymer, and (B) 1 to 30 parts by weight of a polycarbonate resin. A polyester resin composition comprising 1 to 30 parts by weight of (C) elastomer, 3 to 60 parts by weight of (D) fibrous reinforcing material, and the total amount of (A) to (D) is 100 parts by weight. It is disclosed that it is excellent in alkalinity. However, Patent Document 3 does not describe any laser welding.

In addition, International Publication WO00 / 078867 (Patent Document 4) includes (A) a thermoplastic polyester resin, (B) 1 to 25% by weight of an impact resistance imparting agent, (C) a silicone compound and / or a fluorine compound. 0.1 to 15% by weight of compound, (D) 1 to 50% by weight of inorganic filler, and (E) 0.1 to 10% by weight of multifunctional compound such as epoxy compound, isocyanate compound and carboxylic dianhydride It is disclosed that the thermoplastic polyester resin composition is excellent in alkali resistance. However, in such a resin composition, the difference in refractive index between the silicone compound or fluorine compound and PBT is large. Therefore, when a large amount of the compound is added, the light transmittance is greatly reduced, and the laser transmittance is reduced. Since it falls remarkably, welding becomes difficult. Further, if the amount of the compound is reduced in order to ensure light transmittance, sufficient alkali resistance cannot be obtained.
JP 2001-26656 A (Claims) JP-A-10-245481 (Claims) JP 2002-356611 A (Claim 1 and paragraph number [0008]) International Publication No. WO 00/078867 (Claim 1 and pages 2 to 16)

  Accordingly, an object of the present invention is to provide a laser welding PBT resin composition and a molded product thereof which are based on a PBT resin and have high uniform weldability and can be uniformly welded.

  Another object of the present invention is to provide a laser welding PBT-based resin composition that is excellent in laser weldability and provides high welding strength, and a molded product thereof.

  Still another object of the present invention is to provide a laser welding PBT resin composition excellent in alkali resistance, weldability and releasability while being based on a PBT resin, and a molded product thereof.

  Another object of the present invention is to provide a molded article that is excellent in alkali resistance and that does not generate cracks even when it comes into contact with alkali for a long time or at a high frequency, and a method for producing the same.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that (I) a combination of a PBT resin, a polycarbonate resin, an elastomer, and silicone oil is injection-molded, and the laser does not depend on the part of the molded product. It has a high light transmittance and is uniform, and it can uniformly and firmly laser weld the molded product of the PBT resin composition and the counterpart material (resin molded product) at the interface. It has been found that by combining a system stabilizer, a filler or a reinforcing material, and if necessary, a crystallization nucleating agent, the alkali resistance of the resin composition and the molded product can be improved without impairing the uniform transmittance to the laser beam. completed.

  That is, the laser welding resin composition (or laser welding resin composition) of the present invention comprises a polybutylene terephthalate resin (A), an elastomer (B), a polycarbonate resin (C), and a silicone oil (D ). The polybutylene terephthalate resin (A) as the base resin may be polybutylene terephthalate or a polybutylene terephthalate copolymer modified with 30% by mole or less of a copolymerizable monomer.

  The polybutylene terephthalate resin (A) may contain at least a polybutylene terephthalate copolymer. Examples of such a polybutylene terephthalate resin include a polybutylene terephthalate copolymer modified with 5 to 30 mol% of a copolymerizable monomer, or a combination of this copolymer and polybutylene terephthalate.

As the elastomer (B), a segment composed of the aromatic vinyl monomer alone or a copolymer, and a monomer selected from an α-C _2-12 olefin and a diene, or a copolymer, A block or graft copolymer containing the constituted segment, or a hydrogenated product thereof can be used. The refractive index of the elastomer (B) may be about 1.52 to 1.59 at a temperature of 25 ° C.

  The refractive index of the silicone oil (D) may be about 1.35 to 1.60 at 25 ° C., and the viscosity at 25 ° C. may be 50 to 5000 cst.

  The laser weldable resin composition may further contain a phosphorus stabilizer (E), a filler or a reinforcing material (F), and / or a crystallization nucleating agent (G).

  The phosphorus stabilizer (E) may be an alkali metal phosphate, alkaline earth metal phosphate, organic phosphite, organic phosphate, organic phosphonate, organic phosphonite, etc. . The filler or reinforcing material (F) is not particularly limited, and may be, for example, a glassy filler or reinforcing material (glass fiber, glass flake, glass bead, etc.).

  The crystallization nucleating agent (G) is a plate-like or granular material composed of at least one selected from metal oxides, metal carbonates, silicates, metal carbides, and metal nitrides (average particle size 0.05 ˜1 μm metal nitride, etc.).

  The proportion of each component of the resin composition is, for example, 1 to 50 parts by weight of elastomer (B), 5 to 100 parts by weight of polycarbonate resin (C), 100 parts by weight of polybutylene terephthalate resin (A), silicone The oil (D) may be 1 to 10 parts by weight, and the filler or reinforcing material (F) may be about 0 to 100 parts by weight.

  The resin composition comprises 10 to 50 parts by weight of elastomer (B), 5 to 50 parts by weight of polycarbonate resin (C), and silicone oil (D) with respect to 100 parts by weight of polybutylene terephthalate resin (A). 1 to 7 parts by weight (eg 1 to 5 parts by weight), phosphorus stabilizer (E) 0.02 to 3 parts by weight (eg 0.02 to 2 parts by weight), filler or reinforcing material (F) 10 May be contained in an amount of ˜100 parts by weight, and may further contain 0.005 to 5 parts by weight (for example, 0.05 to 2 parts by weight) of the crystallization nucleating agent (G).

  A molded product formed of the resin composition of the present invention has high light transmittance (light transmittance with respect to laser light) and a small difference in transmittance depending on the part of the molded product, and is therefore suitable for laser welding over a wide range. For example, in a molded product formed by injection molding having a length of 80 mm × width of 80 mm × thickness of 2 mm, when a light beam having a wavelength of 800 to 1200 nm is irradiated, the fluctuation range of the light transmittance depending on the part of the molded product (light transmittance The difference between the maximum value and the minimum value may be 10% or less. Further, the molded product may have a weld part (welded part) at least partially, and is selected from an insert part (metal insert part or the like) for inserting a non-resin-based member, a press-fit part, and a screw part. You may have at least one.

  A molded product formed of the resin composition of the present invention is excellent in laser weldability with a counterpart material. Therefore, the present invention includes not only a molded product formed of the resin composition, but also a composite molded product in which this molded product and a resin molded product of a counterpart material are joined by laser welding. This composite molded product is formed by the resin composition, and a molded product positioned on the laser beam transmitting side is brought into contact with a counterpart resin molded product positioned on the laser beam receiving side and irradiated with laser light. And it can manufacture by joining the said molded product and the said resin molded product.

  In the present specification, the term “alkali resistance” means that cracks and cracks in the weld portion do not occur or hardly occur due to immersion in an alkaline solution.

  In the present invention, a combination of a PBT resin, an elastomer, a polycarbonate resin, and silicone oil is used. Therefore, the transmittance is uniform over the entire molded product, and the uniform weldability is high, while being based on the PBT resin. By laser welding, it can be welded uniformly to the counterpart material. Furthermore, it is excellent in laser weldability and high weld strength can be obtained. Therefore, it is possible to obtain a composition and a molded product that are based on a PBT resin and have excellent laser weldability, and a composite molded product that is bonded with high welding strength.

  Further, in the present invention, since the above components are further combined with a phosphorus stabilizer, a filler or a reinforcing material, and, if necessary, a crystallization nucleating agent, while being based on a PBT resin, alkali resistance, weldability and release An object of the present invention is to provide a laser welding PBT resin composition having excellent properties and a molded product thereof.

  Moreover, since the molded article of the present invention is formed of such a resin composition, it is excellent in alkali resistance, and the occurrence of cracks is greatly reduced even when it comes into contact with alkali for a long time or at a high frequency.

[Resin composition]
(A) Polybutylene terephthalate resin As the base resin, polybutylene terephthalate (PBT) resin, butylene terephthalate is a main component (for example, 50 to 100% by weight, preferably 60 to 100% by weight, more preferably 75 to Homopolyester or copolyester (polybutylene terephthalate, polybutylene terephthalate copolyester) and the like.

  As a copolymerizable monomer (hereinafter sometimes simply referred to as a copolymerizable monomer) in a copolyester (butylene terephthalate copolymer or modified PBT resin), dicarboxylic acid excluding terephthalic acid, 1,4-butanediol And diols, oxycarboxylic acids, lactones and the like. The copolymerizable monomers can be used alone or in combination of two or more.

Examples of the dicarboxylic acid include aliphatic dicarboxylic acids (for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, hexadecanedicarboxylic acid, dimer acid, etc. C _4-40 dicarboxylic acids, preferably C _4-14 dicarboxylic acids), cycloaliphatic dicarboxylic acids (eg, C _8-12 dicarboxylic acids such as hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, highmic acid, etc.) Acid), aromatic dicarboxylic acids excluding terephthalic acid (for example, phthalic acid, isophthalic acid; naphthalenedicarboxylic acid such as 2,6-naphthalenedicarboxylic acid; 4,4′-diphenyldicarboxylic acid, 4,4′-diphenoxy ether) Dicarboxylic acid, 4,4'-diphenyl ether dicarbo Acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl ketone C _8-16 dicarboxylic acid such as dicarboxylic acids), or reactive derivatives thereof (e.g., lower alkyl esters (dimethyl phthalate, dimethyl isophthalate Phthalic acid such as (DMI) or C _1-4 alkyl ester of isophthalic acid), derivatives capable of forming an ester such as acid chloride and acid anhydride), and the like. Furthermore, you may use together polyvalent carboxylic acids, such as trimellitic acid and a pyromellitic acid, as needed.

Examples of the diol include aliphatic alkanediols other than 1,4-butanediol (for example, C _2-12 alkanes such as ethylene glycol, trimethylene glycol, propylene glycol, neopentyl glycol, hexanediol, octanediol, and decanediol). Diols, preferably C _2-10 alkanediols), polyoxyalkylene glycols [glycols having a plurality of oxyC _2-4 alkylene units, such as diethylene glycol, dipropylene glycol, ditetramethylene glycol, triethylene glycol, tripropylene glycol Polytetramethylene glycol, etc.], alicyclic diols (eg, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.), aromatic All [e.g., hydroquinone, resorcinol, C _6-14 aromatic diols such as naphthalene diol; biphenol; bisphenols; xylylene glycol], and others. Furthermore, you may use together polyols, such as glycerol, a trimethylol propane, a trimethylol ethane, a pentaerythritol, as needed.

Examples of the bisphenols include bis (4-hydroxyphenyl) methane (bisphenol F), 1,1-bis (4-hydroxyphenyl) ethane (bisphenol AD), 1,1-bis (4-hydroxyphenyl) propane, , 2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2- Bis (hydroxyaryl) C ₁ such as bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane _-6 alkanes; 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydro Bis (hydroxyaryl) C _4-10 cycloalkanes such as xylphenyl) cyclohexane; 4,4′-dihydroxydiphenyl ether; 4,4′-dihydroxydiphenyl sulfone; 4,4′-dihydroxydiphenyl sulfide; 4,4′-dihydroxydiphenyl Examples thereof include ketones and their alkylene oxide adducts. Examples of the alkylene oxide adduct include C _2-3 alkylene oxide adducts of bisphenols (eg, bisphenol A, bisphenol AD, bisphenol F, etc.), such as 2,2-bis- [4- (2-hydroxyethoxy) phenyl. Propane, diethoxylated bisphenol A (EBPA), 2,2-bis- [4- (2-hydroxypropoxy) phenyl] propane, dipropoxylated bisphenol A, and the like. In the alkylene oxide adduct, the number of added moles of alkylene oxide ( _C2-3 alkylene oxide such as ethylene oxide and propylene oxide) is about 1 to 10 moles, preferably about 1 to 5 moles relative to each hydroxyl group.

Examples of the oxycarboxylic acid include oxybenzoic acid, oxynaphthoic acid, hydroxyphenylacetic acid, glycolic acid, oxycaproic acid and other oxycarboxylic acids or derivatives thereof. Lactones include C _3-12 lactones such as propiolactone, butyrolactone, valerolactone, caprolactone (eg, ε-caprolactone).

Preferred copolymerizable monomers include diols [C _2-6 alkylene glycol (such as linear or branched alkylene glycol such as ethylene glycol, trimethylene glycol, propylene glycol, hexanediol, etc.), and a repeating number of 2 to 4]. Polyoxy C _2-4 alkylene glycol having a certain oxyalkylene unit (such as diethylene glycol), bisphenols (such as bisphenols or alkylene oxide adducts thereof), dicarboxylic acids [C _6-12 aliphatic dicarboxylic acids (adipic acid, Pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.), asymmetric aromatic dicarboxylic acids in which the carboxyl group is substituted at the asymmetric position of the arene ring, 1,4-cyclohexanedimethanol, etc.]. Among these compounds, aromatic compounds such as alkylene oxide adducts of bisphenols (particularly bisphenol A), and asymmetric aromatic dicarboxylic acids [phthalic acid, isophthalic acid, and reactive derivatives thereof (dimethylisophthalic acid (DMI)) Etc.) are preferred.

  As the PBT resin, homopolyester (polybutylene terephthalate) and / or copolyester (copolymer) is preferable, and the proportion (modification amount) of the copolymerizable monomer is 30 mol% or less (0 to 30 mol%). is there. In the copolymer, the proportion of the copolymerizable monomer can be selected from the range of, for example, about 0.01 to 30 mol%, and is usually 1 to 30 mol%, preferably 3 to 25 mol%, more preferably 5 to 5 mol%. It is about 20 mol% (for example, 5 to 15 mol%).

  The PBT resin is preferably a resin containing at least a PBT copolymer. Examples of such a PBT resin include a PBT copolymer, or a combination of a PBT copolymer and polybutylene terephthalate. The proportion of the copolymerizable monomer in the PBT copolymer is, for example, 1 to 30 mol%, preferably 3 to 30 mol% (for example, 5 to 30 mol%), more preferably 8 to 25 mol%. About (for example, 10-20 mol%) may be sufficient. A PBT resin containing such a PBT copolymer is suitable for improving alkali resistance.

  A PBT resin (polymer) is prepared by co-polymerizing terephthalic acid or a reactive derivative thereof and 1,4-butanediol with a monomer that can be optionally copolymerized by a conventional method such as transesterification or direct esterification. It can be produced by polymerization.

(B) Elastomer As the elastomer, various thermoplastic elastomers can be used.

  The elastomer is usually composed of a hard segment (or a hard component) and a soft segment (or a soft component). The elastomer (thermoplastic elastomer) may be a polystyrene-based elastomer, a polyester-based elastomer, or the like. The said elastomer can be used individually or in combination of 2 or more types.

Examples of the polystyrene-based elastomer include a hard segment composed of an aromatic vinyl monomer such as styrene, α-methylstyrene, vinyltoluene or a copolymer, and α-C _2-12 olefin (ethylene, propylene, 1 A block or graft copolymer with a soft segment composed of a single or copolymer of a monomer selected from -butene, 1-hexene, 1-octene, etc.), diene (butadiene, isoprene, etc.) (or Examples thereof include hydrogenated products thereof. The polystyrene-based elastomer is usually composed of a hard segment composed of the aromatic vinyl monomer alone or a copolymer and the α-olefin and / or diene monomer alone or a copolymer. It may be a block or graft copolymer with a soft segment (or a hydrogenated product thereof).

  The polystyrene elastomer is an acid-modified elastomer modified with an acid or acid anhydride such as (meth) acrylic acid or maleic anhydride, a copolymerizable monomer having a glycidyl group or an epoxy group (glycidyl (meth) acrylate, etc.) ) Or an elastomer having a reactive functional group such as an epoxy-modified elastomer obtained by epoxidizing an unsaturated bond of the elastomer. From the viewpoint of laser weldability and alkali resistance, the type of polystyrene elastomer is not particularly limited, but from the viewpoint of heat resistance and chemical resistance, it is also preferable to use an elastomer having a hydrogenated product or a reactive functional group.

  Typical polystyrene elastomers include styrene-diene-styrene block copolymers [styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), etc.], hydrogenated blocks Copolymer [Styrene-ethylene-butylene-styrene block copolymer (or hydrogenated (styrene-butadiene-styrene block copolymer)) (SEBS), styrene-ethylene-propylene-styrene block copolymer (or hydrogenated) (Styrene-isoprene-styrene block copolymer)) (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), random styrene-butadiene copolymer hydrogenated polymer], functional group ( Epoxy group, carboxy Group, acid anhydride group, etc.) modified copolymer [epoxidized styrene-diene copolymer in which unsaturated bond of diene is epoxidized (epoxidized styrene-diene-styrene block copolymer or hydrogen thereof) And the like).

As the polyester-based elastomer, polyester-polyester type thermoplastic elastomer [for example, poly C _2-4 alkylene arylate (in particular, a homopolymer having a polybutylene terephthalate unit or a copolymer component (ethylene glycol, isophthalic acid, etc.) 5 to 5 A hard segment composed of an aromatic crystalline polyester such as a copolymer copolymerized at a ratio of about 20 mol%) and an aliphatic polyester (C _2-6 alkylene glycol such as polyethylene adipate and polybutylene adipate) and C A block copolymer with a soft segment composed of _6-12 alkanedicarboxylic acid or the like), a polyester-polyether thermoplastic elastomer [for example, a hard segment composed of the aromatic crystalline polyester and , Poly A block copolymer with a soft segment composed of a polyether such as polyoxy C _2-4 alkylene glycol such as tetramethylene ether glycol], a liquid crystalline thermoplastic elastomer [for example, a hard segment composed of liquid crystal molecules; Examples include block copolymers with soft segments composed of aliphatic polyesters].

  The block structure of the thermoplastic elastomer is not particularly limited, and may be a triblock structure, a multiblock structure, a star block structure, or the like.

  In the thermoplastic elastomer, the weight ratio of the hard segment (or hard component) and the soft segment (or soft component) is usually the former / the latter = 10/90 to 90/10, preferably 20/80 to 80/20, More preferably, it is about 30/70 to 70/30 (for example, 40/60 to 60/40).

  The refractive index of the elastomer may be, for example, 1.52 to 1.59, preferably about 1.53 to 1.58 at a temperature of 25 ° C. If the refractive index of the elastomer is too small or too large, scattering of transmitted light becomes significant, which may lead to a decrease in welding energy.

  The amount of the elastomer (B) used is 1 to 50 parts by weight (for example, 1 to 40 parts by weight), preferably 2 to 40 parts by weight (for example, 2 to 30 parts by weight) with respect to 100 parts by weight of the PBT resin (A). Part), more preferably about 5 to 35 parts by weight (for example, 5 to 30 parts by weight). The ratio of the elastomer is, for example, about 5 to 50 parts by weight, preferably about 10 to 50 parts by weight, and more preferably about 10 to 40 parts by weight with respect to 100 parts by weight of the PBT resin (A). Also good.

(C) Polycarbonate (PC) Resin The polycarbonate resin (C) can be obtained by reacting a dihydroxy compound with a carbonate such as phosgene or diphenyl carbonate. The dihydroxy compound may be an alicyclic compound or the like, but is preferably an aromatic compound (particularly a bisphenol compound).

Examples of the bisphenol compound include bisphenols exemplified in the section of the PBT resin (for example, bis (hydroxyaryl) C _1-6 alkane; bis (hydroxyaryl) C _4-10 cycloalkane; 4,4′-dihydroxydiphenyl ether; 4,4′-dihydroxydiphenyl sulfone; 4,4′-dihydroxydiphenyl sulfide; 4,4′-dihydroxydiphenyl ketone, etc.). Preferred polycarbonate resins include bisphenol F, bisphenol AD, bisphenol A, polycarbonates based on 1,1-bis (hydroxyphenyl) C _5-6 cycloalkane, especially bisphenol A type polycarbonates.

  The amount of the polycarbonate resin (C) used can be selected from a range of about 5 to 100 parts by weight (for example, 10 to 100 parts by weight) with respect to 100 parts by weight of the PBT resin (A). It may be about parts by weight (for example, 10 to 60 parts by weight). Moreover, the said usage-amount may be 5-50 weight part (for example, 20-40 weight part), More preferably, about 10-30 weight part may be sufficient.

(D) Silicone oil Examples of the silicone oil (D) include dimethylpolysiloxane, diphenylpolysiloxane, tetramethyltetraphenyltrisiloxane, pentaphenyltrimethylsiloxane, methylphenylsiloxane, methyldodecylmethyl (2-phenylpropyl) siloxane, and the like. Can be illustrated. Silicone oils are modified silicone oils such as ether-modified silicone oils introduced with polyoxy C _2-4 alkylene such as polyoxyethylene units, acid-modified silicone oils introduced with carboxyl groups or acid anhydride groups, epoxy groups It may be an epoxy-modified silicone oil introduced, an amino-modified silicone oil introduced with an amino group, or the like. These silicone oils can be used alone or in combination of two or more.

The viscosity of the silicone oil, for example, room temperature (e.g., 15-25 ° C.) ^{in, 1~100000cst (1 × 10 -6 ~1} × 10 -1 m 2 / s), preferably 10~100000cst (1 × 10 ^{- 5} to 1 × 10 ⁻¹ m ² / s), more preferably about 100 to 80000 cst (1 × 10 ^{−4 to} 0.8 × 10 ⁻¹ m ² / s). When improving the alkali resistance, especially in combination with such phosphorus-based stabilizer and / or fillers, for example, at ordinary temperature (e.g., 15~25 ℃), 50~5000cst (1 × 10 -5 ~5 × 10 - ³ m ² / s), preferably 100 to 5000 cst (1 × 10 ^{−4 to} 5 × 10 ⁻³ m ² / s), more preferably 100 to 3000 cst (1 × 10 ^{−4 to} 3 × 10 ⁻³ m ^2). It is preferable to use silicone oil having a viscosity of about / s).

  Since the refractive index of silicone oil affects the laser beam transmission, it is 1.35 to 1.60, preferably 1.38 to 1.58 (for example, 1.38 to 1.55) at a temperature of 25 ° C. Degree.

  The amount of the silicone oil (D) used is 1 to 10 parts by weight (for example, 1 to 8 parts by weight), preferably 1 to 7 parts by weight (for example, 1 to 5 parts by weight) with respect to 100 parts by weight of the PBT resin. )

(E) Phosphorus stabilizers Phosphorus stabilizers (E) include inorganic phosphorus stabilizers (such as alkali metal or alkaline earth metal phosphates), and organic phosphorus stabilizers (organic phosphorous esters, organic And at least one selected from phosphoric acid esters, organic phosphonic acid esters, and organic phosphonous acid esters. The phosphorus stabilizer may be either liquid or solid. In addition, it is known that a transesterification reaction occurs between the PBT resin and the polycarbonate resin, and the transesterification reaction proceeds rapidly when the cylinder temperature is increased or the residence time is increased with molding. , There may be variations in permeability and the product cannot be released. When a phosphorus stabilizer is used, such a reaction can also be prevented.

  Examples of the alkali metal or alkaline earth metal salt of phosphoric acid include phosphoric acid or a corresponding hydrogen phosphate (for example, potassium phosphate, sodium phosphate [(monosodium phosphate (sodium dihydrogen phosphate), phosphoric acid Alkali metal salts such as disodium (sodium hydrogen phosphate, sodium monohydrogen phosphate, disodium hydrogen phosphate, etc.); calcium phosphate [(primary calcium phosphate (calcium dihydrogen phosphate, bis (dihydrogen phosphate) calcium) Monohydrate, etc.), dibasic calcium phosphate (eg calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, etc.)], alkaline earth such as magnesium phosphate (magnesium hydrogen phosphate, magnesium dihydrogen phosphate, etc.) Examples of the metal salt include an anhydride or a hydrate It may be either.

Examples of organic phosphites include alkyl phosphites (mono to tri C _6-24 alkyl phosphites) such as bis (2-ethylhexyl) phosphite, tridecyl phosphite, triisodecyl phosphite, and di-n-octadecyl phosphite. Substituted with aryl groups such as diphenylisodecyl phosphite, triphenyl phosphite, tris (2-cyclohexylphenyl) phosphite, bis or tris (t-butylphenyl) phosphite, tris (nonylphenyl) phosphite Aryl phosphites (mono to tri C _6-10 aryl phosphites etc.) _optionally having a group (alkyl group, cycloalkyl group etc.); aralkyl phosphites (mono to tris (C ₆ ) etc.) _-10 aryl-C _1-6 alkyl ) Phosphite etc.), bisarylpentaerythritol diphosphite [bis (2,6-dit-butyl-4-methylphenyl) pentaerythritol diphosphite etc.], bisaralkyl pentaerythritol diphosphite etc. It is done.

Examples of the organic phosphate include mono- or trialkyl esters of phosphoric acid (for example, mono- or di-C _6-24 alkyl esters such as monostearyl acid phosphate and distearyl acid phosphate), mono- to triaryl esters of phosphoric acid ( Mono- or di-C _6-10 aryl phosphate, etc.) such as mono- or diphenyl phosphate.

Examples of the organic phosphonate include mono-dialkyl phosphonates such as distearyl phosphonates (C _6-24 alkyl phosphonates); mono-aryls optionally having substituents on aryl groups such as diphenyl phosphonates and di (nonylphenyl) phosphonates Or diaryl phosphonate (such as C _6-10 aryl phosphonate); mono- or diaralkyl phosphonate (such as C _6-10 aryl-C _1-6 alkyl phosphonate) such as dibenzyl phosphonate.

  Examples of organic phosphonous acid esters include tetrakis (2,4-di-t-butyl) -4,4′-biphenylenediphosphonite, (2,4-di-t-butylphenyl) -4,4′-biphenyl. And biphenyl diphosphonite such as range phosphonite.

  When the phosphorus stabilizer (E) is used, the ratio is, for example, 0.02 to 3 parts by weight, preferably 0.02 to 2 parts by weight (for example, 0. 2 parts by weight) with respect to 100 parts by weight of the PBT resin. (05 to 2 parts by weight), more preferably about 0.02 to 1 part by weight (for example, 0.05 to 0.5 part by weight).

(F) Filler or reinforcing material The resin composition may contain the filler or reinforcing material (E) as long as it does not adversely affect the laser beam transmission. Such fillers or reinforcing materials (F) include fibrous reinforcing materials [for example, inorganic fibers (for example, glass fibers, silica fibers, alumina fibers, silica-alumina fibers, aluminum silicate fibers, zirconia fibers, potassium titanate). Fibers, whiskers (such as whiskers such as silicon carbide, alumina, boron nitride, etc.), organic fibers (for example, aliphatic or aromatic polyamide, aromatic polyester, fluororesin, acrylic resin such as polyacrylonitrile, rayon, etc. Fiber) etc.], plate-like reinforcing material [eg talc, mica, glass flakes etc.], granular reinforcing material [eg glass beads, glass powder, milled fiber (eg milled glass fiber etc.)], wollastonite (Wollastonite) is included. The wollastonite may be in the form of a plate, a column, a fiber or the like. The average diameter of the fibrous reinforcing material may be, for example, about 1 to 50 μm (preferably 3 to 30 μm), and the average length may be, for example, about 100 μm to 3 mm (preferably 500 μm to 1 mm). Further, the average particle diameter of the plate-like or granular reinforcing material may be, for example, about 0.1 to 100 μm, preferably about 0.1 to 50 μm. These reinforcing materials can be used alone or in combination of two or more.

  Of these fillers or reinforcing materials (F), a reinforcing material capable of transmitting laser light is preferred. Such a reinforcing material can be selected according to the wavelength of the laser beam. Examples of such a reinforcing material include glass-based or glassy fillers or reinforcing materials (glass fibers, glass flakes, glass beads, etc.), and in particular, glass fibers such as glass having high strength and rigidity. Fibers (such as chopped strands) are preferred.

  The ratio of the filler or the reinforcing material (F) can be selected from a range of about 0 to 100 parts by weight (for example, 0 to 80 parts by weight) with respect to 100 parts by weight of the PBT resin, and usually 10 to 100 parts by weight. (For example, 20 to 100 parts by weight), preferably about 10 to 80 parts by weight (for example, 20 to 80 parts by weight), and more preferably about 30 to 80 parts by weight (for example, 50 to 70 parts by weight).

(G) Crystallization nucleating agent As crystallization nucleating agent (G), in addition to organic nucleating agents such as rosin, inorganic nucleating agents such as metal oxides (silica, alumina, zirconia, titanium oxide, iron oxide, zinc oxide) Etc.), metal carbonate (calcium carbonate, magnesium carbonate, barium carbonate, etc.), silicate (calcium silicate, aluminum silicate, talc, etc.), metal carbide (silicon carbide, etc.), metal nitride (silicon nitride, nitride) Examples thereof include boron and tantalum nitride. The crystallization nucleating agent may be in the form of powder or plate. Of these, metal nitrides, particularly boron nitride, are preferred.

  The average particle diameter of the crystallization nucleating agent may be, for example, 0.05 to 1 μm, preferably 0.1 to 0.8 μm, and more preferably about 0.1 to 0.5 μm.

  When the resin composition contains the crystallization nucleating agent (G), the proportion is, for example, 0.001 to 5 parts by weight (for example, 0.001 to 3 parts by weight) with respect to 100 parts by weight of the PBT resin. ), Preferably 0.005 to 2 parts by weight, more preferably about 0.01 to 1 part by weight.

  Various additives such as stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), flame retardants, lubricants, mold release agents, antistatic agents, inorganic fillers, dyes and pigments, etc. Colorants, dispersants, antistatic agents, fillers, and the like may be added. Moreover, in order to improve hydrolysis resistance, heat shock resistance, etc., you may add epoxy compounds, such as a bisphenol A type epoxy compound and a novolak type epoxy compound. Further, a reflection component for laser light (for example, a component that almost reflects incident light in the wavelength region of 800 to 1200 nm) may be used as long as the laser weldability is not impaired. Usually, such a reflection component is used. Is often not added. If necessary, other resins (such as styrene resins, acrylic resins, thermoplastic resins such as polyethylene terephthalate resins, thermosetting resins, etc.) may be used in combination.

  The PBT resin composition of the present invention may be a powder mixture or a molten mixture (such as pellets). The resin composition of the present invention has a high moldability and can produce a molded product or a molded product having high mechanical strength and heat resistance. In particular, a molded article formed with the resin composition of the present invention has high light transmittance (particularly light transmittance with respect to laser light) despite being formed with a PBT resin composition, and is suitable for laser welding. ing. For example, in a molded product [length 80 mm × width 80 mm × thickness 2 mm] formed by injection molding from a gate having a width of 2 mm by the side gate method (for example, injection molding under the conditions described in the examples), 800 to 1200 nm Is 15% or more (for example, about 15 to 80%) in the thickness direction, preferably 18% or more (for example, about 18 to 75%), more preferably 20% or more (for example, 20 to 70). %)). The light transmittance may be 25% or more (for example, about 25 to 60%). In addition, the molded product formed from the resin composition of the present invention has little variation in light transmittance depending on the part (location) of the molded product, and the laser beam is transmitted uniformly. For example, in the molded product [length 80 mm × width 80 mm × thickness 2 mm] formed by injection molding the resin composition of the present invention, when a light beam (laser light) having a wavelength of 800 to 1200 nm is irradiated in the thickness direction, The fluctuation range of the light transmittance depending on the part of the molded product is 10% or less (0 to 10%), preferably 7% or less (0 to 7%), more preferably 5% or less (0 to 5%), especially 3%. The following (0 to 3%), and may be about 2 to 6%. Therefore, laser welding can be performed uniformly and firmly over a wide range, and the airtightness of the welding interface can be improved. Furthermore, since the weldability by laser light is high, it is useful for producing a molded body for welding using laser light.

[Molded body]
The molded body is made of PBT resin (A), elastomer (B), polycarbonate resin (C), silicone oil (D), and other components (phosphorus stabilizer (E), filler or A resin composition composed of a reinforcing material (E) and / or a crystallization nucleating agent (G), etc. in a conventional manner, for example, (1) a single-screw or twin-screw extruder mixed with each component (2) Once a pellet (master batch) with a different composition is prepared, a predetermined amount of the pellet is mixed (diluted) and used for molding, and a predetermined composition is obtained. (3) A method of directly charging one or more of each component into a molding machine. In addition, you may prepare a pellet by mixing a brittle component (glass type reinforcing material), after melt-mixing the component except a brittle component (glass type reinforcing material etc.), for example.

  The molded body may be formed by melt-kneading the PBT resin composition and using a conventional method such as extrusion molding, injection molding, compression molding, blow molding, vacuum molding, rotational molding, gas injection molding, etc. Molded by injection molding. The conditions for injection molding can be appropriately selected. For example, a PBT resin composition is melt-kneaded at about 250 to 280 ° C., pellets are prepared as necessary, and the cylinder temperature is about 250 to 280 ° C. with an injection molding machine. It may be injection molded. The mold temperature may be 60 ° C. or less (for example, about 40 to 60 ° C.), but in order to obtain a molded body having a uniform laser beam transmittance, the mold temperature is 65 to 90 ° C. (for example, 70 to 90 ° C.) is preferable.

  The shape of the molded product is not particularly limited. However, since the molded product is used by joining with a mating material (other resin molded product) by laser welding, the shape usually has at least a contact surface (such as a flat surface) (for example, a plate shape). It is. In addition, since the molded product of the present invention has a high transmittance to the laser beam, the thickness of the molded product (the thickness in the direction in which the laser beam is transmitted) at the site where the laser beam is transmitted (the site where the laser beam is transmitted) is from a wide range. For example, it may be 0.1 to 3 mm, preferably 0.5 to 3 mm, and more preferably about 0.1 to 2 mm.

  Molded products are welded parts (that is, welds that are formed at the interface between resin flows by joining multiple resin flows in the mold cavity as the molded product is molded), and non-metals such as metals. An insert portion for inserting the member when integrally formed with a member (such as a hard member) made of a material, a press-fit portion for press-fitting the member, and screwing for screwing the member or the like It may have a part. Since the molded article of the present invention is excellent in weldability and also in alkali resistance, cracks and cracks do not occur even in the above-described parts when immersed in an alkaline solution. The molded product may have at least one site as described above.

  The laser light source is not particularly limited, and for example, a dye laser, a gas laser (excimer laser, argon laser, krypton laser, helium-neon laser, etc.), a solid-state laser (YAG laser, etc.), a semiconductor laser, and the like can be used. As the laser light, a pulse laser is usually used.

  Since the molded product is excellent in laser weldability, it is usually preferable to weld the resin molded product of the counterpart material by laser welding, but if necessary, other thermal welding methods, for example, vibration welding method, It may be welded to another resin molded product by ultrasonic welding, hot plate welding, or the like, or laser welding and other welding methods may be combined.

  The present invention also discloses laser molded composite molded articles. In this composite molded product, a molded product (first molded product) formed of the PBT resin composition and a counterpart resin molded product (second molded product, adherend) are joined by laser welding. Are integrated. For example, the first molded product and the second molded product are brought into contact (particularly at least the joint portion is in surface contact) and irradiated with laser light, whereby the interface between the first molded product and the second molded product is changed. By melting at least partially to bring the joining surfaces into close contact and cooling, the two types of molded articles can be joined and integrated into a single molded body. In such a composite molded body, when the molded body of the present invention is used, a high bonding strength can be obtained by fusing, and a high fusing strength equivalent to a non-fusing member that has not been fused by laser light irradiation can be maintained. it can. Therefore, even if laser welding is performed, the bonding strength is not substantially reduced, and a strongly molded composite molded body can be obtained.

  The resin constituting the resin molded product of the counterpart material is not particularly limited, and various thermoplastic resins, for example, olefin resins, vinyl resins, styrene resins, acrylic resins, polyester resins, polyamide resins. And polycarbonate resins. Among these resins, resins of the same type or system as the resins constituting the PBT resin composition (polyester resins such as PBT resins and PET resins (aromatic polyester resins), polycarbonate resins, etc.) Or you may comprise a partner material with the composition.

  As the resin constituting the counterpart material, a silicone compound such as silicone oil or silicone resin may be used in combination, and it is preferable to use a PBT resin containing a silicone compound. For example, you may form a 1st molded object and a 2nd molded object with the PBT-type resin composition of this invention, respectively. In particular, a resin containing a silicone compound (PBT resin) in a member that absorbs laser light, for example, a PBT resin composition of the present invention, a composite using a resin composition described in International Publication No. WO00 / 078867. When the molded body is formed, the alkali resistance can be further improved.

  The PBT resin composition (or the first molded body) is a colorant (for example, JP 2000-309694 A) unless the laser transmittance (for example, the transmittance for laser light having a wavelength of 800 to 1200 nm) is significantly impaired. And a coloring agent described in JP-A No. 2001-71384).

  Colorants that are non-absorbable with respect to laser light (inorganic or organic dyes and pigments), such as yellow dyes (inorganic pigments such as cadmium yellow, organic pigments such as benzidine yellow), orange dyes (hansa) Yellow), red pigment (inorganic pigment such as red pigment, organic pigment such as lake red), blue pigment (inorganic pigment such as cobalt blue, organic pigment such as phthalocyanine blue), green dyed pigment (inorganic pigment such as chrome green) Organic pigments such as phthalocyanine green) and purple dyes. Such a colorant may be used alone or may be adjusted to a desired color tone using a combination of a plurality of colorants. For example, subtractive color mixing (such as a combination of a plurality of dyes, for example, a combination of a yellow dye and a purple dye, a combination of a yellow dye, a red dye, and a blue dye) can be used to render the resin achromatic (gray or Black) can also be colored.

  The total amount of the colorant used in the first molded body is not particularly limited. For example, 0.01 to 10 parts by weight (for example, 0.01 to 7 parts by weight) with respect to 100 parts by weight of the PBT resin. However, it may preferably be about 0.01 to 5 parts by weight.

  The adherend (or counterpart material) may contain an absorber or a colorant for laser light. The colorant can be selected according to the wavelength of the laser beam, and is an inorganic pigment [black pigment such as carbon black (for example, acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, etc.), iron oxide Red pigments such as red, orange pigments such as molybdate orange, white pigments such as titanium oxide], organic pigments (yellow pigment, orange pigment, red pigment, blue pigment, green pigment, purple pigment, etc.). These absorbents can be used alone or in combination of two or more. As the absorbent, usually black pigments or dyes, particularly carbon black can be used. The average particle diameter of carbon black is usually 10 to 1000 nm, preferably about 10 to 100 nm. The ratio of the colorant is about 0.1 to 10% by weight, preferably about 0.5 to 5% by weight (for example, 0.5 to 3% by weight) with respect to the entire adherend.

  In addition, a resin sheet (such as a PBT resin sheet) containing a laser light absorber or a colorant such as carbon black is sandwiched between the first and second molded bodies, or a laser light absorber is applied. Then, after the two molded bodies are brought into close contact, bonding may be performed by laser light irradiation. In such a method, even if the laser beam absorption of the second molded body is small, both molded bodies can be joined efficiently. In addition, about the detail of the resin sheet containing the said coloring agent, patent 1829720 gazette etc. can be referred, for example.

  The laser light irradiation is usually performed in the direction from the first molded body to the second molded body, and generates heat at the interface of the second molded body containing the absorbent or the colorant, whereby the first The molded body and the second molded body are fused. That is, the 1st molded object (molded product formed with the resin composition of this invention) located in the permeation | transmission side of a laser beam, and the 2nd molded object (resin molding of a counterpart material) located in the light-receiving side of a laser beam Product) and irradiating with laser light, the interface portion between the first molded body and the second molded body can be melted and firmly bonded, and a composite molded product is obtained. If necessary, a lens system may be used to focus the laser light on the interface between the first molded product and the second molded product and fuse the contact interface.

  Preferred embodiments of the present invention are as follows.

  (1) The laser weldable resin composition, wherein the polybutylene terephthalate resin (A) is at least one selected from a homopolyester and a copolyester having a butylene terephthalate unit.

  The polybutylene terephthalate resin (A) is at least one selected from polybutylene terephthalate and copolyester, and the copolymerizable monomer of the copolyester is a bisphenol or an alkylene oxide adduct thereof, an asymmetric aromatic dicarboxylic acid, and The resin composition which is at least one selected from these ester-forming derivatives.

  The polybutylene terephthalate resin (A) is at least one selected from polybutylene terephthalate and copolyester, and the copolymerizable monomer of the copolyester is an alkylene oxide adduct of phthalic acid, isophthalic acid, bisphenol A, and these The said resin composition which is at least 1 type selected from the reactive derivative of.

  The polybutylene terephthalate resin (A) is at least one selected from polybutylene terephthalate copolymers modified with polybutylene terephthalate and 1 to 30 mol% (for example, 1 to 20 mol%) copolymerizable monomers. The resin composition.

  (2) The said resin composition whose elastomer (B) is a polystyrene-type elastomer.

  (3) The said resin composition whose refractive index of silicone oil (D) is 1.35-1.60.

  (4) 1 to 40 parts by weight of elastomer (B), 5 to 80 parts by weight of polycarbonate resin (C), and 1 to 10 silicone oils (D) with respect to 100 parts by weight of polybutylene terephthalate resin (A) The said resin composition containing a weight part and a filler or a reinforcing material (F) 0-100 weight part.

  (5) 10 to 40 parts by weight of elastomer (B), 5 to 30 parts by weight of polycarbonate resin (C), and 1 to 5 silicone oils (D) with respect to 100 parts by weight of polybutylene terephthalate resin (A) A resin composition comprising 1 part by weight, 1 to 5 parts by weight of a phosphorus stabilizer (E), and 10 to 80 parts by weight of a filler or reinforcing material (F).

  (6) In a molded product having a length of 80 mm × width of 80 mm × thickness of 2 mm (side gate gate width of 2 mm) formed by injection molding, the light transmittance at a wavelength of 800 to 1200 nm is 17% or more (for example, 20% or more). Yes, the resin composition having a variation range of light transmittance of 7% or less depending on a part of the molded product when irradiated with light having a wavelength of 800 to 1200 nm.

  (7) An injection molded product (or laser weldable injection molded product) formed of the resin composition.

  The resulting composite molded article has high welding strength and little damage to the PBT resin due to laser light irradiation, so it can be used in various applications such as electrical / electronic parts, office automation (OA) equipment parts, home appliance parts. It can be applied to machine mechanism parts, automobile mechanism parts and the like. In particular, it can be suitably used for automobile 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, and the like.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  In Examples and Comparative Examples, the following PBT resin (A), elastomer (B), polycarbonate resin (C), silicone oil (D), phosphorus stabilizer (E), filler or reinforcing material (F) And a crystallization nucleating agent (G) were used.

(A) PBT resin
(A-1) Dimethylisophthalic acid (DMI) -modified PBT resin In the reaction of terephthalic acid with 1,4-butanediol, DMI 12 as a copolymerization component is used instead of a part of terephthalic acid (12.5 mol%). Modified polybutylene terephthalate was prepared using 0.5 mol%.

(A-2) Dimethylisophthalic acid (DMI) modified PBT resin In the reaction of terephthalic acid and 1,4-butanediol, DMI 17 as a copolymerization component was used instead of a part of terephthalic acid (17.0 mol%). Modified polybutylene terephthalate was prepared using 0.0 mol%.

(A-3) Polybutylene terephthalate (PBT resin, manufactured by Wintech Polymer Co., Ltd., DX2000)
(B) Elastomer
(B-1) Epoxy group-containing polystyrene-based thermoplastic elastomer 70% by weight of styrene, 1.0% by weight of oxirane, 6.0 g / 10 min (200 ° C., 5 kg load), Shore A = 93
(B-2) Polyester thermoplastic elastomer (manufactured by Toyobo Co., Ltd.)
(B-3) Ethylene-styrene copolymer (manufactured by NOF Corporation)
(B-4) Hydrogenated styrene isoprene butadiene styrene copolymer (styrene content 30% by weight, specific gravity = 0.92, solution viscosity of 5% by weight toluene solution (30 ° C.) = 90 mPa · sec)
(B-5) Ethylenehexene copolymer-graft-styrene / butyl acrylate / methyl methacrylate copolymer styrene content 40% (manufactured by NOF Corporation)
(B-6) Ethylene ethyl acrylate Melt flow index = 0.5 g / 10 min (190 ° C., 2.16 kg), Shore A = 88, Ethyl acrylate content = 23 wt%
(C) Polycarbonate resin Polycarbonate resin (average molecular weight 22000)
(D) Silicone oil

(E) Phosphorus stabilizer
(E-1) Monobasic calcium phosphate
(E-2) Monosodium phosphate
(E-3) Distearyl acid phosphate (F) Filler or reinforcement
(F-1) Glass fiber: Nittobo Co., Ltd., average fiber diameter φ11 μm chopped strand. Aminosilane / polyfunctional epoxy-treated product.

(G) Crystallizing nucleating agent
(G-1) Boron nitride (average particle size 0.3 μm, specific surface area = 45 m ² / g)
Examples 1-7 , Reference Examples 8-9, Examples 10-12 and Comparative Examples 1-2
Each component was kneaded at 260 ° C. by a twin screw extruder (manufactured by Nippon Steel Works, 30 mmφ) at the ratio shown in Table 2 and Table 3 to produce pellets. The obtained pellets were injection-molded with an injection molding machine (manufactured by Toshiba Corporation) under the conditions of a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C., and a test piece A (80 mm long × 80 mm wide × 2 mm thick, side gate) , Gate width 2 mm) and test piece C for weld test (length 80 mm × width 80 mm × thickness 1 mm, side gate, gate width 1 mm).

  Further, as the adherend B to the test piece A, 100 parts by weight of the pellets and 5 parts by weight of black coloring carbon black (trade name “2020C”, manufactured by Wintech Polymer Co., Ltd.) are used. A box-shaped specimen B having a thickness of 2 mm was produced. The box-shaped specimen B has a rectangular shape with a length of 80 mm, a width of 40 mm, and a height of 20 mm, and an upper end surface is opened. Further, after sealing by laser welding, a hole (φ10 mm) for applying an internal pressure was formed on the lower end surface using a drilling machine. In addition, the test body B acts as a heating element by laser light.

  As shown in FIG. 1, a test piece A (3) is overlapped and brought into contact with the open end of a box-shaped specimen B (4), and a laser welder (manufactured by Leister) is used to make a header (1 The focal point of the laser beam (2) from (2) was adjusted and focused on the contact surface between the test piece A and the box-shaped specimen B with a line width of 1.5 mm. Then, laser light with a wavelength of 940 nm is irradiated and welded from the side of the test piece A (3) under the condition of a scanning speed of 10 mm / second, and the opening of the box-shaped test body B is sealed with the test piece A (3). A box-shaped composite was prepared.

(1) Airtightness (uniform weldability)
With respect to the box-shaped composite of the test piece A and the test piece B obtained by laser welding, an internal pressure of 0.02 MPa was applied in water for 30 seconds, and the airtightness was evaluated by the presence or absence of generation of bubbles at the joint.

(2) Light transmittance For each part of the test piece A, the light transmittance (%) at a wavelength of 940 nm was measured using a spectrophotometer [“V570” manufactured by JASCO Corporation] to obtain the maximum light transmittance. The difference (range of fluctuation,%) between the value and the minimum value was calculated.

(3) Alkali resistance With 1% strain applied to test piece C, it was immersed in a 10% strength by weight sodium hydroxide aqueous solution at 23 ° C., and cracks were generated on the surface of test piece C after 1 hour and 10 hours. In addition, the actual state of the weld was observed with a microscope.

○: No crack and weld part crack ×: Crack and / or weld part crack The results of Examples and Comparative Examples are shown in Tables 2 and 3.

  In the examples, the light transmittance of the test piece A with respect to the laser light is uniform, and can be welded uniformly, and the airtightness is high. On the other hand, in the comparative example, the light transmittance varies greatly depending on the part, and the airtightness is low.

Examples 13-22 and Comparative Examples 3-6
Each component was kneaded at 260 ° C. by a twin screw extruder (manufactured by Nippon Steel Works, 30 mmφ) at the ratio shown in Table 4 and Table 6 to produce pellets. The obtained pellets were injection-molded with an injection molding machine (manufactured by Toshiba Corporation) under the conditions of a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C., and a test piece A (length 80 mm × width 80 mm × thickness 2 mm, side gate) , Gate width 2 mm), and test piece C for weld test (length 80 mm × width 80 mm × thickness 1 mm, side gate, gate width 1 mm).

  Moreover, as the to-be-welded object B with respect to the said test piece A, the box-shaped composite body was produced by the method similar to Examples 1-12 using the box-shaped test body B similar to the said Examples 1-12.

  Further, 100 parts by weight of the pellets and 5 parts by weight of black coloring carbon black (manufactured by Wintech Polymer Co., Ltd., trade name “2020C”) were injection-molded. A welded specimen D was prepared. Note that the test piece D acts as a heating element by laser light.

  As shown in FIG. 2, the test piece A (6) is overlapped with the test piece D (5) so that a part thereof is in contact, and a laser welding machine (manufactured by Leister) is used to start from the header (1) of the laser oscillator. The focus of the laser beam (2) was adjusted and focused on the contact surface between the test piece A and the test piece D with a line width of 1.5 mm. Then, laser light having a wavelength of 940 nm was irradiated and welded from the side of the test piece A (5) at a scanning speed of 10 mm / second.

(1) Light transmittance The light transmittance (%) at a wavelength of 940 nm was measured at the center of the test piece A using a spectrophotometer [“V570” manufactured by JASCO Corporation], and the maximum value of the light transmittance was measured. And the difference between the minimum value and the minimum value (variation width,%) was calculated. The representative value was the central value.

(2) Airtightness (uniform weldability)
With respect to the box-shaped composite of the test piece A and the test piece B obtained by laser welding, an internal pressure of 0.02 MPa was applied in water for 30 seconds, and the airtightness was evaluated by the presence or absence of generation of bubbles at the joint.

(3) Laser weldability The test piece A and the test piece D were cut into strips having a size of 80 mm × 10 mm × 2 mm. Then, after overlapping as shown in FIG. 2, a laser welding machine (manufactured by Leister) was used to weld a laser beam having a wavelength of 940 nm under a scanning speed of 10 mm / second. Next, the tensile shear strength was measured with an orientec universal testing machine RTC-1325.

(4) Alkali resistance With 1% strain applied to test piece C, the test piece C was immersed in a 10% strength by weight aqueous sodium hydroxide solution at 23 ° C., and after 1 hour, 10 hours, 100 hours and 200 hours, test piece C The surface was observed with a stereomicroscope for cracks and weld cracks.

○: No crack and weld crack ×: Crack and / or weld crack
(5) Moldability In the process of preparing the test piece A, the resin composition is retained in the cylinder for 15 minutes, and then injection molding is performed. The obtained test piece A is deformed, and the sprue and the runner part have no problem. An evaluation was made as to whether the mold could be released. Moreover, the transmittance | permeability (%) in wavelength 940nm was measured for the center part of the test piece A produced after making it retain in a cylinder as mentioned above using the spectrophotometer, and the transmittance | permeability by molding conditions was confirmed. .

○: No problem ×: The test piece was greatly deformed by the eject pin in the step of releasing from the mold, and the problem that the sprue or runner could not be removed from the mold occurred.

  The results are shown in Tables 5 and 6. Tables 4 and 5 also show the compositions and results of Examples 2 and 3.

FIG. 1 is a schematic diagram for explaining laser welding in Examples 1 to 7, Reference Examples 8 to 9, Examples 10 to 12, and Comparative Examples 1 to 2. FIG. 2 is a schematic view for explaining laser welding in Examples 13 to 22 and Comparative Examples 3 to 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser head 2 ... Laser beam 3, 6 ... Test piece A
4 ... Specimen B
5 ... Specimen D

Claims (16)

A molded article formed of a laser welding resin composition containing a polybutylene terephthalate resin (A), an elastomer (B), a polycarbonate resin (C), and a silicone oil (D), and a counterpart resin A composite molded product bonded to a molded product by laser welding, wherein the polybutylene terephthalate resin (A) is a polybutylene terephthalate copolymer modified with 30% by mole or less of a copolymerizable monomer. And the elastomer (B) is a segment composed of an aromatic vinyl monomer alone or a copolymer, and a monomer selected from an α-C _2-12 olefin and a diene. A block or graft copolymer containing a segment composed of a coalescence, or a composite molded product that is a hydrogenated product thereof . The composite molded article according to claim 1, wherein the refractive index of the elastomer (B) is 1.52-1.59 at a temperature of 25C. The composite molded article according to claim 1, wherein the refractive index of the silicone oil (D) is 1.35 to 1.60 at a temperature of 25 ° C, and the viscosity of the silicone oil (D) is 50 to 5000 cst. 1 to 50 parts by weight of elastomer (B), 5 to 100 parts by weight of polycarbonate resin (C), and 1 to 10 parts by weight of silicone oil (D) with respect to 100 parts by weight of polybutylene terephthalate resin (A) The composite molded article according to claim 1, comprising: The composite molded article according to claim 1 , wherein the laser welding resin composition further comprises a phosphorus stabilizer (E). The composite molded article according to claim 5 , wherein the phosphorus stabilizer (E) is an inorganic phosphorus stabilizer. The composite molded article according to claim 1 , wherein the resin composition for laser welding further contains a filler or a reinforcing material (F). The composite molded article according to claim 7 , wherein the filler or reinforcing material (F) is glassy. The composite molded article according to claim 1 , wherein the laser welding resin composition further comprises a crystallization nucleating agent (G). The composite molded article according to claim 9, wherein the crystallization nucleating agent (G) is boron nitride having an average particle diameter of 0.05 to 1 μm. 10-100 parts by weight of elastomer (B), 5-50 parts by weight of polycarbonate resin (C), 1-7 parts by weight of silicone oil (D), 100 parts by weight of polybutylene terephthalate resin (A) The composite molded article according to claim 1, comprising 0.02 to 3 parts by weight of a stabilizer (E) and 10 to 100 parts by weight of a filler or reinforcing material (F). The composite molded article according to claim 11 , wherein the resin composition for laser welding further comprises 0.005 to 5 parts by weight of a crystallization nucleating agent (G). When the resin composition for laser welding is irradiated with light having a wavelength of 800 to 1200 nm in a molded product having a length of 80 mm × width of 80 mm × thickness of 2 mm formed by injection molding , the light transmittance varies depending on the part of the molded product. The composite molded article according to claim 1 , which is a resin composition having a width of 10 % or less. Molded article formed by laser welding resin composition according to claim 1 composite molded article according with a weld portion at least in part. Molded article formed by laser welding the resin composition for the insert portion, the press-fitting portion and the claims 1 composite molded article according to at least one selected from the threaded portion. A molded product formed of a laser welding resin composition and positioned on the laser beam transmitting side is brought into contact with a mating resin molded product positioned on the laser beam receiving side and irradiated with laser light to form the molded product. The method for producing a composite molded product according to claim 1 , wherein the product and the resin molded product are joined.

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