JP2008133341A - Black polyester resin composition for laser welding and molded product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition having excellent laser welding characteristics and to provide a molded product firmly bonded by laser welding. <P>SOLUTION: The black polyester resin composition for laser welding is obtained by compounding 100 pts.wt. of (a) a polyester resin with 0-100 pts.wt. of (b) a reinforcing filler and 0.01-1 pt.wt. of (c) a colorant. Furthermore, the (c) colorant is a combination of two or more kinds of colorants containing a phthalocyanine-based pigment. The light transmittance at 960 nm wavelength of the molded product composed of the resin composition and having 1.5 mm thickness is ≥15%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a black laser-welded polyester resin composition. In particular, the present invention relates to a black laser-welded polyester resin composition that can be firmly bonded to other resin members by laser welding.

Thermoplastic polyester resins typified by polybutylene terephthalate resins and polyethylene terephthalate resins are easy to process and are excellent in mechanical properties, electrical properties, heat resistance, and other physical and chemical properties. For this reason, it is widely used for vehicle parts, electrical / electronic equipment parts and other precision equipment parts. In particular, polybutylene terephthalate resin is suitably used for injection molding because of its high crystallization rate. In recent years, among the various uses, development has progressed to products that seal electric circuit parts such as vehicle electrical parts (control units, etc.), various sensor parts, connector parts, and the like.
Here, as a construction method for such sealing, an adhesive, ultrasonic welding, hot plate welding, laser welding, and the like have been performed. However, the method using an adhesive has a problem of environmental load such as contamination of the surroundings in addition to time loss until curing. In addition, ultrasonic welding, hot plate welding, and the like have been pointed out as problems such as damage to products due to vibration and heat, and post-treatment required due to generation of wear powder and burrs. On the other hand, laser welding is non-contact, does not generate wear powder or burrs, and has little damage to the product.

  Here, products that seal electrical circuits such as vehicle electrical components, sensor components, connector components, etc. are often colored black. However, the resin composition containing a black colorant typified by carbon black or iron oxide pigment has a very low laser light transmission, and when the laser output is increased, melting on the laser incident side surface, In some cases, defects such as smoke generation and bubbles due to abnormal heat generation at the bonding interface may occur, and the transmittance may decrease due to foreign matter or haze caused by a deteriorated resin. Therefore, there is a problem that the resin composition containing the black colorant cannot be used for the laser transmission side member.

In order to solve these problems, it contains a black polyester resin composition (Patent Document 1) translucent to laser light in which two types of pigments, a yellow pigment and a violet pigment, are blended in a resin, an anthraquinone dye, and a monoazo complex dye A laser light transmitting colored thermoplastic resin composition (Patent Document 2) is disclosed. However, the resin compositions disclosed therein are not sufficient in ultraviolet aging resistance and heat resistance, and there are restrictions on the environment in which they are used.
Further, Patent Document 3 describes a thermoplastic resin composition capable of laser transmission welding using at least two kinds of colorants, but the description using an example using a phthalocyanine pigment also uses a polyester resin. There is no description of the examples, and there is no description of UV aging resistance.
Furthermore, Patent Document 4 describes using a phthalocyanine pigment as a compound for absorbing near-infrared laser. However, a phthalocyanine pigment is added to the resin composition on the transmission side, that is, the laser irradiation side. There is no description or suggestion about the addition.

Japanese Patent No. 3737926 Special table 2004-517995 gazette Special table 2003-517075 gazette JP 2003-183524 A

  The present invention has been made in view of the above circumstances, and the purpose thereof is a black laser-welded polyester resin composition excellent in laser welding characteristics (hereinafter sometimes referred to as “polyester resin composition of the present invention”). Another object of the present invention is to provide a molded article using the polyester resin composition of the present invention and a method for producing the molded article.

As a result of intensive research to solve the above problems, the present inventors have excellent welding characteristics by developing a black hue using a combination of two or more colorants including a phthalocyanine pigment. It was found that a black polyester resin composition for laser welding was obtained.
Further, the black laser-welded polyester resin composition was found to have good UV aging resistance, and the present invention was completed.

The present invention has been completed based on the above findings, and the gist is as follows.
(1) A polyester resin composition comprising (b) 0 to 100 parts by weight of a reinforcing filler and (c) 0.01 to 1 part by weight of a colorant, with respect to 100 parts by weight of the (a) polyester resin, The (c) colorant is a combination of two or more colorants containing a phthalocyanine pigment, and the light transmittance at a wavelength of 960 nm of a molded product having a thickness of 1.5 mm made of the resin composition is 15% or more. A polyester resin composition for black laser welding.
(2) (a) The polyester resin composition for black laser welding according to (1), wherein the polyester resin is polybutylene terephthalate.
(3) The black laser welding polyester resin composition according to (1) or (2), wherein the reinforcing filler (b) is a glass fiber.
(4) The black laser welding polyester resin composition according to any one of (1) to (3), wherein the phthalocyanine pigment is a blue colorant.
(5) The black laser welding polyester resin composition according to any one of (1) to (4), which contains a brown colorant as a colorant other than the phthalocyanine pigment (c).
(6) The black laser welding polyester resin composition according to (5), wherein the brown colorant is a methine dye.
(7) The black laser welding polyester resin composition according to any one of (1) to (6), which is used for a member on a laser transmission side.
(8) A member made of the black laser welding polyester resin composition (A) according to any one of (1) to (7) and a member made of the resin composition (B) having laser absorptivity, A molded article obtained by welding by irradiating a laser beam from the member side made of the resin composition (A).
(9) A member made of the black laser-welding polyester resin composition (A) according to any one of (1) to (7) and a member made of the resin composition (B) having laser absorption, The manufacturing method of the molded article including the process of irradiating and welding a laser beam from the member side which consists of the said resin composition (A).

  According to the present invention, a black polyester resin composition excellent in laser welding characteristics was obtained. In addition, by using the black laser welding resin composition of the present invention, it is possible to obtain a molded product in which members are more firmly bonded to each other.

Hereinafter, the contents of the present invention will be described in detail. In the specification of the present application, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
The “black” resin composition in the present invention is a molded product having a thickness of 2 mm obtained by molding a resin composition comprising 0.6 parts by weight of carbon black with respect to 100 parts by weight of polybutylene terephthalate resin. This means that the hue difference (color difference: ΔE) based on the hue of the L ^* a ^* b ^* color system is 10 or less, preferably 5 or less.

<(A) Polyester resin>
As the (a) polyester resin employed in the present invention, known polyester resins can be widely used. (A) The polyester resin may be used alone or in combination of two or more. (A) The polyester resin is preferably a polyester resin comprising dicarboxylic acid or a derivative thereof and a diol.
As the dicarboxylic acid or derivative thereof, aromatic dicarboxylic acid, alicyclic dicarboxylic acid, and aliphatic dicarboxylic acid, and esters of these lower alkyls or glycols are preferred, and aromatic dicarboxylic acids or their lower alkyls (for example, C1-4) or an ester of glycol is more preferable, and terephthalic acid or a lower alkyl ester thereof is more preferable.
Aromatic dicarboxylic acids include terephthalic acid, phthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-benzophenone dicarboxylic acid, 4,4′-diphenoxy. Preferred examples include ethanedicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid and 2,6-naphthalenedicarboxylic acid.
Preferred examples of the alicyclic dicarboxylic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.
Preferred examples of the aliphatic dicarboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.
These dicarboxylic acids or derivatives thereof may be used alone or in combination of two or more.

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

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

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

  The intrinsic viscosity of the PBT resin in the present invention is preferably 0.5 to 3.0 dl / g as measured at 30 ° C. in a mixed solvent of tetrachloroethane and phenol of 1: 1 (weight ratio). 5 dl / g is more preferable, and 0.6 to 1.3 dl / g is still more preferable. By setting the intrinsic viscosity to 0.5 dl / g or more, the mechanical properties can be improved, and by setting the intrinsic viscosity to 3.0 dl / g or less, the fluidity is kept good and the molding process is easier. Become. Furthermore, it is good also as an intrinsic viscosity within the said range by using together 2 or more types of PBT resin from which intrinsic viscosity differs.

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

<(B) Reinforcing filler>
The reinforcing filler (b) used in the present invention is not particularly defined, and a wide range of fiber shapes, plate shapes, granular materials, and mixtures thereof can be adopted.
Examples of fibrous materials include glass fibers, carbon fibers, silica alumina fibers, zirconia fibers, boron fibers, boron nitride fibers, silicon nitride potassium titanate fibers, metal fibers and other inorganic fibers, aromatic polyamide fibers, and fluororesin fibers. Organic fibers such as
Examples of the plate-like material include glass flakes, mica, and metal foil.
Examples of the particulate material include ceramic beads, wollastonite, talc, clay, mica, zeolite, kaolin, potassium titanate, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, and magnesium hydroxide.
In the present invention, among the reinforcing fillers (b), a fibrous material is preferably used.

  (B) When the shape of the reinforcing filler is fibrous, the average fiber diameter is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 50 μm, particularly preferably 3 to 30 μm, and 5 to 20 μm. Most preferred. By adopting such a fiber diameter, the mechanical properties can be further improved. Moreover, especially average fiber length is although it does not restrict | limit, 0.1-20 mm is preferable and 1-10 mm is more preferable. By making the average fiber length 0.1 mm or more, the reinforcing effect by the fibrous filler is more effectively expressed, and by making the average fiber length 20 mm or less, (a) melt kneading or strengthening with a polyester resin Molding of the polyester resin composition becomes easier.

The reinforcing filler (b) used in the present invention is surface-treated in order to increase the affinity between the polyester resin and the reinforcing filler, improve the interfacial adhesion, and eliminate or reduce the opacity factor due to void formation at the interface. Those having been surface-treated with a silane coupling agent and an epoxy resin are more preferable.
Examples of the silane coupling agent include amino silane, epoxy silane, allyl silane, and vinyl silane. Of these, aminosilanes are preferred. Preferred examples of the amino silane coupling agent include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ- (2-aminoethyl) aminopropyltrimethoxysilane. The content of the silane coupling agent in the surface treatment agent is preferably 0.1 to 8% by weight, and more preferably 0.5 to 5% by weight.
The epoxy resin is preferably a polyfunctional epoxy resin such as a phenol novolac type epoxy resin and a cresol novolac type epoxy resin. The content of the epoxy resin in the surface treatment agent is preferably 1 to 20% by weight, and more preferably 2 to 10% by weight.
(B) As a component contained in the surface treating agent used for the reinforcing filler, a combination of an amino-based silane coupling agent and a novolac type epoxy resin is particularly preferable. By making the surface treating agent such a structure, the inorganic functional group of the amino silane coupling agent is (b) the reinforcing filler surface, the organic functional group of aminosilane is the glycidyl group of the epoxy resin, and the glycidyl of the epoxy resin. The group is highly reactive with (a) the polyester resin, and as a result, (b) the interfacial adhesion between the reinforcing filler and the epoxy resin is improved. Therefore, the mechanical properties and hydrolysis resistance of the polyester resin composition of the present invention are improved, and further, the opacity due to void formation at the interface is reduced, so that the transmittance is also improved.

(B) The surface treatment agent used for the reinforcing filler contains other components such as a urethane resin, an acrylic resin, an antistatic agent, a lubricant, and a water repellent within the scope of the present invention. Can be included.
As a treatment method with a surface treatment agent, for example, a surface treatment with a surface treatment agent can be performed in advance as described in JP-A Nos. 2001-172055 and 53-106749. In addition, when preparing the polyester resin composition of the present invention, a surface treatment agent can be added to the surface treatment separately from the untreated (b) reinforcing filler.
(B) The adhesion amount of the surface treatment agent to the reinforcing filler is preferably 0.01 to 5% by weight, and more preferably 0.05 to 2% by weight. By making it 0.01% by weight or more, the mechanical strength tends to be improved more effectively, and by making it 5% by weight or less, a necessary and sufficient effect can be obtained and it is economical.

As the material of the reinforcing filler (b) in the present invention, glass is preferable. Specifically, they are glass fiber, glass flakes, glass beads, and glass powder. Among them, it is preferable to use glass having a refractive index of 1.560 to 1.600. The glass is usually composed of components constituting the E glass (refractive index of 1.550) used for the polyester resin, except for B ₂ O ₃ and F ₂ components, and the ratio of components such as MgO, TiO ₂ , ZnO, etc. By adopting the glass, it is possible to improve the laser transmittance of the polyester resin composition of the present invention.
The glass employed in the present invention is preferably a glass fiber from the viewpoint of mechanical strength and rigidity, and a long fiber type (roving) type or a short fiber type (chopped strand) type is more preferably used.

  The blending amount of the (b) reinforcing filler is 0 to 100 parts by weight, preferably 5 to 70 parts by weight, based on 100 parts by weight of the (a) polyester resin.

<(C) Colorant>
In the polyester resin composition of the present invention, (c) a combination of two or more colorants including a phthalocyanine pigment is used as the colorant. The combination of colorants is preferably a combination containing a phthalocyanine pigment and a brown colorant.

 As the phthalocyanine-based pigment, those having a phthalocyanine structure can be widely used. Generally, metal phthalocyanine in which a metal is introduced into the center of the skeleton is used. The phthalocyanine structure is described in detail in Chapter 2 of the book “Latest Pigment Applied Technology” (March 25, 1988, second edition) published by CMC Co., Ltd., for example. Excerpted from the book, the phthalocyanine structure is a huge cyclic compound having four isoindoles with a similar structure to tetraazaporphyrin. Specific examples include Color Index (C.I.) Pigment Blue 15: 1, C.I. Pigment Blue 15: 3, C.I. Pigment Blue 16, C.I. Pigment Green 7, and the like. Further preferred are colorants having a blue hue (indicated by Blue in the Color Index classification), among which heat resistance, UV aging resistance and bleed resistance under high temperature and high humidity are good. CIPigment Blue 15: 1 and CIPigment Blue 15: 3 are particularly preferred.

 The brown colorant is a color index classified by Brown. Examples of the brown colorant included in the polyester resin composition of the present invention include methine dyes (CISolvent Brown 53), azo pigments (CIPigment Brown 23), benzimidazolone pigments (CIPigment Brown 25), and inorganic pigments. (CIPigment Brown 6, CIPigment Brown 24) is a preferred example.

In the present invention, a methine dye is preferable among the brown colorants. Methine dyes (a) have excellent affinity with polyester resin and high heat resistance, so there is little fading and thermal degradation of laser welded parts, and it is possible to further improve the weldability and UV aging resistance of molded products. is there.
The kind of methine dye is not particularly defined, and is a dye having one or more methine groups (—CH═), and examples thereof include methine dyes, polymethine dyes, azomethine dyes, and cyanine dyes. Among these methine dyes, those having good heat resistance and low sublimation are preferable, and CISolvent Brown 53, which is also an FDA registered product, is particularly preferable.

The polyester resin composition of the present invention may contain a colorant other than the above colorants within a range not departing from the gist of the present invention. As such a colorant, a blue colorant other than the phthalocyanine pigments described above is preferable. Here, the blue colorant means a material represented by Blue according to the classification by Color Index.
Examples of blue colorants other than the phthalocyanine pigments described above include anthraquinone dyes (CISolvent Blue 87, CISolvent Blue 97) and inorganic pigments (CIPigment Blue 29).

  (C) The compounding quantity of a coloring agent is 0.01-1 weight part with respect to 100 weight part of (a) polyester resin, Preferably it is 0.03-0.8 weight part, More preferably, it is 0.05- 0.5 parts by weight. (C) By making the compounding quantity of a coloring agent 0.01 weight part or more, a black hue can be given to a resin composition, and sufficient heat resistance and ultraviolet aging resistance can be provided. When the amount is 1 part by weight or less, the dispersibility in the polyester resin is improved, and the bleeding on the surface of the molded product and the decrease in the mechanical strength of the resin composition are preferably suppressed.

(C) As for the addition amount of the phthalocyanine pigment in a coloring agent, 0.003-0.03 weight part is preferable with respect to 100 weight part of polyester resins, More preferably, it is 0.005-0.02 weight part. By adding in such a ratio, there is an advantage that the weather resistance is good and the cost is low.
Moreover, when using a brown coloring agent, the addition amount is preferably 0.03 to 0.5 parts by weight, and more preferably 0.05 to 0.3 parts by weight with respect to 100 parts by weight of the polyester resin. By adding at such a ratio, the weather resistance and bleed resistance become better.

<Other additives>
You may mix | blend another additive with the polyester resin composition of this invention in the range which does not deviate from the meaning of this invention. Examples of other additives include antioxidants, flame retardants, heat stabilizers, lubricants, mold release agents, catalyst deactivators, crystal nucleating agents, and crystallization accelerators. These additives can be added during or after polymerization of the (a) polyester resin. Further, (a) In order to impart desired performance to the polyester resin, an ultraviolet absorber, a weather resistance stabilizer, an antistatic agent, a foaming agent, a plasticizer, an impact resistance improving agent, and the like may be blended.

The antioxidant has the effect of improving the heat aging resistance of the polyester resin composition of the present invention more effectively and further improving the retention such as color tone, tensile strength and elongation. As this antioxidant, it is preferable to mix | blend 1 or more types of antioxidant chosen from a phenolic antioxidant, sulfur type antioxidant, and phosphorus antioxidant.
The blending amount of the antioxidant is preferably 0.001 to 2 parts by weight, and more preferably 0.03 to 1.5 parts by weight with respect to 100 parts by weight of the polyester resin (a).

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

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

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

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

  In the PBT resin composition of the present invention, the blending amount of the phenol-based antioxidant, the sulfur-based antioxidant and the phosphorus-based antioxidant is preferably 0.001 to 1. with respect to 100 parts by weight of the (a) polyester resin. 5 parts by weight, more preferably 0.03 to 1 part by weight. By making the blending amount of the antioxidant 0.001 part by weight or more, the antioxidant effect is better exhibited, and by making the blending amount of the antioxidant 1.5 parts by weight or less, oxidation heat stability It is possible to further suppress the deterioration of the resin and to make it more difficult for the resin to decompose during melt-kneading.

The flame retardant is not particularly limited, and examples thereof include organic halogen compounds, antimony compounds, phosphorus compounds, other organic flame retardants, and inorganic flame retardants. Examples of the organic halogen compound include brominated polycarbonate, brominated epoxy resin, brominated phenoxy resin, brominated polyphenylene ether resin, brominated polystyrene resin, brominated bisphenol A, and pentabromobenzyl polyacrylate. Examples of the antimony compound include antimony trioxide, antimony pentoxide, and sodium antimonate. As a phosphorus compound, phosphate ester, polyphosphoric acid, ammonium polyphosphate, red phosphorus etc. are mentioned, for example. Examples of other organic flame retardants include nitrogen compounds such as melamine and cyanuric acid. Examples of other inorganic flame retardants include aluminum hydroxide, magnesium hydroxide, silicon compound, and boron compound.
The blending amount of these flame retardants is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the (a) polyester resin. By setting the blending amount of the flame retardant to 0.1 parts by weight or more, flame retardancy can be expressed more effectively, and by setting it to 50 parts by weight or less, physical properties, particularly mechanical strength, are kept higher. be able to.

In the polyester resin composition of the present invention, polyethylene resin, polypropylene resin, polystyrene resin, polyacrylonitrile resin, polymethacrylic ester resin, acrylonitrile / butadiene / styrene resin (ABS resin), as long as the effects of the present invention are not impaired. Contains thermoplastic resins such as polycarbonate resin, polyamide resin, polyphenylene sulfide resin, polyethylene terephthalate resin, liquid crystal polyester resin, polyacetal resin, polyphenylene oxide resin, and thermosetting resins such as epoxy resin, phenol resin, melamine resin, and silicone resin. can do. These thermoplastic resins and thermosetting resins can also be used in combination of two or more.
The blending amount of these resins is preferably 50% by weight or less, more preferably 45% by weight or less in the (a) polyester resin.

  Although the manufacturing method in particular of the polyester resin composition of this invention is not restrict | limited, The method of using the uniaxial or biaxial extruder which has the equipment which can be devolatilized from a vent port as a kneading machine is preferable. The components (a) to (c) and other additives may be supplied all at once to the kneader, or other compounding components may be sequentially supplied to the resin component (a). Moreover, you may mix and knead | mix beforehand 2 or more types of components chosen from each component. For example, (a) a master pellet prepared by kneading a colorant more than a predetermined blending ratio in a part of a polyester resin is prepared in advance, and this is melt-mixed and extruded with the remaining blending components to obtain a predetermined blending ratio. By this, the resin composition in the present invention can be obtained.

  The method for producing a molded article using the polyester resin composition of the present invention is not particularly limited, and molding methods generally used for thermoplastic resins, that is, molding such as injection molding, hollow molding, extrusion molding, and press molding. The law can be applied. In this case, a particularly preferable molding method is injection molding because of good fluidity. In the injection molding, the resin temperature is preferably controlled to 240 to 280 ° C.

The polyester resin composition of the present invention can be used as a black laser-weldable polyester resin material. In particular, by using the polyester resin composition of the present invention, at least one of the members using the resin composition can be firmly bonded to each other, which is preferable for producing a molded product having two or more resin members. Can be used.
The shape of the member is not particularly limited, but is usually a shape having at least a surface contact portion (a flat surface or a curved surface) because the members are joined and used by laser welding.
In laser welding, laser light that has passed through a laser-transmitting member is absorbed by the laser-absorbing member, melted, and both members are welded. Since the polyester resin composition of the present invention has high transparency to laser light despite being colored, it can be preferably used as a member that transmits laser light. Here, the thickness of the member through which the laser is transmitted (thickness in the direction through which the laser beam is transmitted) can be appropriately determined in consideration of the use, the composition of the composition, and the like, and is, for example, 5 mm or less, preferably 4 mm or less.

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

More specifically, for example, when welding a member made of the polyester resin composition (A) of the present invention and a member made of a resin composition (B) having laser absorption, first, the locations where the two are to be welded together Contact each other. At this time, surface contact is desirable between the welded portions of the two, and may be flat surfaces, curved surfaces, or a combination of flat and curved surfaces. Next, laser light is irradiated from the member side made of the polyester resin composition (A) of the present invention (preferably irradiated perpendicularly to the adhesive surface). At this time, the laser beam may be condensed at the interface between the two using a lens system if necessary. The condensed beam passes through the member made of the polyester resin composition (A) of the present invention, is absorbed near the surface of the member made of the resin composition (B), generates heat, and melts. Next, the heat is transferred to the member made of the polyester resin composition (A) of the present invention by heat conduction and melted to form a molten pool at the interface between the two, and after cooling, both are joined.
The molded product in which the members are welded in this way has high bonding strength. The molded product in the present invention refers to a product in which at least two or more members are welded, and includes a finished product and a part as well as a member constituting a part thereof.

The member made of the resin composition (B) is not particularly limited as long as it contains at least a resin and can be welded to the member made of the polyester resin composition (A) of the present invention. The resin contained in the resin composition (B) is preferably a thermoplastic resin. For example, an olefin resin, a vinyl resin, a styrene resin, an acrylic resin, a polyester resin, a polyamide resin, or a polycarbonate resin. Polyacetal resins and the like are mentioned, and polyester resins, polyamide resins, and polycarbonate resins are particularly preferably used from the viewpoint of good compatibility. Moreover, the resin composition (B) may be comprised from 1 type, or 2 or more types of resin. Furthermore, the polyester resin composition (A) of the present invention may be used.
In addition, the resin contained in the resin composition (B) preferably has an absorption wavelength within the range of the wavelength of the laser beam to be irradiated. Furthermore, you may express the absorption characteristic by making a resin composition (B) contain and add a light absorber, for example, a color pigment. Examples of the color pigment include inorganic pigments (black pigments such as carbon black (for example, acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black), red pigments such as iron oxide red, molyb Examples include orange pigments such as date orange, white pigments such as titanium oxide, and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.) Among them, inorganic pigments generally have strong hiding power, The resin composition (B) on the laser absorption side can be preferably used, and these light absorbers may be used alone or in combination of two or more.
It is preferable that the compounding quantity of a light absorber is 0.01-1 weight part with respect to 100 weight part of resin components.

  The integrally molded product obtained in the present invention has high welding strength and ultraviolet aging resistance, and less damage to the resin due to laser light irradiation, so it can be used in various applications such as various storage containers, electrical / electronic equipment parts, It can be applied to office automate (OA) equipment parts, home appliance parts, machine mechanism parts, vehicle mechanism parts, and the like. In particular, food containers, chemical containers, oil and fat product containers, vehicle electrical parts (various control units, ignition coil parts, etc.), motor parts, various sensor parts, connector parts, switch parts, relay parts, coil parts, transformer parts It can be suitably used for lamp parts and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example at all unless the summary is exceeded.

[Various measurement methods]
(1) Light transmittance Examples 1 to 3 in Table 1 molded using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd .: model SE-50D) at a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. Flat plates having a size of 13 mm × 128 mm, a thickness of 1.5 mmt and a thickness of 2 mmt made of the resin compositions having the compositions shown in Comparative Examples 1 to 5 were prepared. The light transmittance of each of these flat plates was measured with a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation: UV-3100PC). For the light transmittance, the ratio of the transmitted light intensity and the incident light intensity in the near-infrared region 960 nm was expressed as a percentage.

(2) Laser welding strength test The test pieces were overlapped as shown in FIG. In FIG. 1, (a) shows a view of the test piece from the side, and (b) shows a view of the test piece from above. Further, in FIG. 1, 1 is a test piece prepared in the above (1), 2 is a test piece made of a resin composition (B) which is a mating material to be joined (made in the same manner as in the above (1)). Reference numerals 3 indicate laser irradiation locations.

The test piece 1 (13 mm × 128 mm, flat plate of 2 mm thickness) used in the light transmittance measurement is overlapped with the laser transmission side and the test piece 2 made of the resin composition (B) is overlapped with the laser absorption side, and the laser is irradiated from the transmission side. did. The laser welding apparatus was a batch irradiation type IRAM-300 manufactured by Nippon Emerson Co., Ltd., the laser light wavelength was 960 nm, the welding spot was 3 mm × 6 mm, and the pressure was 4.8 MPa. The laser irradiation time was set to 13 sec when the test piece 1 did not contain the reinforcing filler, and 17 sec when the test piece 1 contained the reinforcing filler.
The laser welding strength was measured using a tensile tester (type 5544 manufactured by Instron) and the tensile speed was evaluated at 5 mm / sec. The tensile strength is indicated by the tensile shear fracture strength of the welded portion.

(3) Tensile strength test Examples 1 to 3 in Table 1 and comparison using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd .: Model SG-75MIII) at a cylinder temperature of 250 ° C and a mold temperature of 80 ° C. ISO test pieces made of the resin compositions having the compositions shown in Examples 1 to 5 were prepared. The tensile strength of the ISO test piece was measured according to ISO 527.

(4) Blackness (a1) With respect to 100 parts by weight of the polybutylene terephthalate resin, (c6) 0.6 parts by weight of carbon black is blended, and a resin composition is prepared by the same manufacturing method as in Example 1 described later. (1) A flat plate having a size of 13 mm × 128 mm and a thickness of 2 mmt was prepared in the same manner as the flat plate for measuring light transmittance. The hue of the obtained flat plate was evaluated by the L ^* a ^* b ^* color system, and this was used as a black standard.
The hue of the flat plate having a thickness of 2 mmt for measuring light transmittance was measured, and the difference in hue from the black reference (color difference: ΔE) was evaluated. The smaller the ΔE, the better the blackness.
For the measurement, a spectrocolorimeter (manufactured by Konica Minolta: CM-3600d) was used, and ΔE was determined by the following equation.
ΔE = ((ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ) ^1/2

(5) UV resistance acceleration test (UV aging resistance)
In accordance with the test method described in “Technical Data No. 130, UV Degradation Acceleration Test of Lighting Equipment Wires / Cables” issued by the Japan Electrical Wire Manufacturers Association, the above ISO test piece was subjected to JIS under an atmosphere of 120 ° C. After carrying out H400 (400 W mercury lamp) irradiation specified in C7604 for 500 hours, the tensile strength was measured according to ISO527. Moreover, the tensile strength retention was calculated | required according to following Formula.
Tensile strength retention (%) = (Tensile strength after treatment / Tensile strength before treatment) × 100
Further, the fading degree was evaluated by using a spectrocolorimeter (manufactured by Konica Minolta: CM-3600d) and the color difference (ΔE) before and after the test. ΔE was determined by the following equation, as with the blackness.
ΔE = ((ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ) ^1/2

[Raw material of resin composition]
(A) Polyester resin (a1) Polybutylene terephthalate resin: manufactured by Mitsubishi Engineering Plastics Co., Ltd., “trade name: NOVADURAN (registered trademark) 5008”, intrinsic viscosity [η] = 0.85 dl / g
(A2) Polybutylene terephthalate resin: “Mitsubishi Engineering Plastics”, “trade name: Nova Duran (registered trademark) 5020”, intrinsic viscosity [η] = 1.20 dl / g

(B) Reinforced filler glass fiber: chopped strand treated with a surface treatment agent, manufactured by Owens Corning, “trade name: 183H-13P”, average fiber diameter 13 μm, average fiber length 3 mm

(C) Colorant (c1) Phthalocyanine pigment: C.I. I. Pigment Blue 15: 3, manufactured by Dainippon Ink & Chemicals, Inc., “Product Name: FASTOGEN BLUE GB-7HS”
(C2) Methine dye: C.I. I. Solvent Brown 53, manufactured by Clariant, "Product name: Polysynthren Brown R"
(C3) Methine dye: C.I. I. Solvent Violet 49, manufactured by Clariant, "Product name: Polysynthren Violet G"
(C4) Anthraquinone-based and perylene-based mixed dyes: “Arimoto Chemical Industry Co., Ltd.,“ trade name: DA-412 ”
(C5) Anthraquinone dyes: C.I. I. Solvent Blue 97, manufactured by LANXESS, "Product name: Macrolex-BLUE-2R"
(C6) Carbon black: “Product name: MA600B” manufactured by Mitsubishi Chemical Corporation

Antioxidant: Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], “trade name: Irganox 1010” manufactured by Ciba Specialty Chemicals

[Resin composition (B)]
The resin composition of Comparative Example 5 was blended with 0.6 part by weight of (c6) carbon black with respect to 100 parts by weight of (a1) polybutylene terephthalate resin.

[Examples 1 to 3, Comparative Examples 1 to 5]
(A) A polybutylene terephthalate resin, (c) a colorant, and an antioxidant were blended in the ratios shown in Table 1 and mixed for 20 minutes with a tumbler. The obtained raw material mixture was supplied to a hopper and melt-kneaded using a twin-screw extruder (manufactured by Nippon Steel Works: TEX30C, barrel 9 block configuration) with a cylinder temperature set to 250 ° C. (B) When glass fiber was blended, it was supplied from the fifth block counted from the hopper by the side feed method and melt-kneaded. The evaluation mentioned above was performed using the obtained resin composition. The evaluation results are shown in Table 1.

  As shown in Table 1, by adding two or more colorants containing (c1) phthalocyanine pigment as a colorant, there is little resin deterioration due to ultraviolet rays, and excellent balance of laser transmission and laser weldability. It was revealed that a black polyester resin composition can be obtained. That is, by using the polyester resin composition of the present invention, strong laser welding with other members can be easily performed.

The polyester resin composition of the present invention is excellent in laser welding characteristics such as laser transparency and ultraviolet aging resistance, and is particularly suitable for products for sealing electrical circuits such as vehicle electrical parts, sensor parts, connector parts, etc. Can be used.
Moreover, by using the polyester resin composition of the present invention, it becomes possible to provide a molded product in which members are more firmly bonded. Such molded products are widely used industrially, and their utility value is extremely high.

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

Explanation of symbols

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

Claims (9)

(A) A polyester resin composition obtained by blending 0 to 100 parts by weight of a reinforcing filler and (c) 0.01 to 1 part by weight of a colorant with respect to 100 parts by weight of a polyester resin, ) The colorant is a combination of two or more colorants containing a phthalocyanine pigment, and the light transmittance at a wavelength of 960 nm of a molded product having a thickness of 1.5 mm made of the resin composition is 15% or more. Black laser welding polyester resin composition. (A) The polyester resin composition for black laser welding according to claim 1, wherein the polyester resin is polybutylene terephthalate. (B) The black laser welding polyester resin composition according to claim 1 or 2, wherein the reinforcing filler is glass fiber. The polyester resin composition for black laser welding according to any one of claims 1 to 3, wherein the phthalocyanine pigment is a blue colorant. The black laser welding polyester resin composition according to any one of claims 1 to 4, comprising a brown colorant as a colorant other than the phthalocyanine pigment (c). The black laser welding polyester resin composition according to claim 5, wherein the brown colorant is a methine dye. The polyester resin composition for black laser welding according to any one of claims 1 to 6, which is used for a member on a laser transmission side. A member made of the black laser-welding polyester resin composition (A) according to any one of claims 1 to 7 and a member made of a resin composition (B) having laser absorbability are used as the resin composition ( A molded article formed by irradiating and welding a laser beam from the member side consisting of A). A member made of the black laser-welding polyester resin composition (A) according to any one of claims 1 to 7 and a member made of a resin composition (B) having laser absorbability are used as the resin composition ( The manufacturing method of the molded article including the process of irradiating and welding a laser beam from the member side which consists of A).

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