JP2008222831A - Black polyester resin composition for laser welding, and molded article obtained using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition exhibiting excellent laser welding properties and a molded article strongly bonded by laser welding. <P>SOLUTION: The black polyester resin composition for laser welding comprises (a) 100 pts.wt. of a polyester resin and, incorporated therewith, (b) 0-100 pts.wt. of a reinforcing filler, (c) 0.01-1 pt.wt. of a purple colorant and (d) 0.01-5 pts.wt. of a compound having a salicylic amide structure. <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 welding 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. As a method of sealing, adhesive, ultrasonic welding, hot plate welding, laser welding, and the like have been performed. However, the construction 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, it has been pointed out that ultrasonic welding, hot plate welding, and the like require post-treatment due to vibration, damage to the product due to heat, and 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, resin compositions containing black colorants, such as carbon black and iron oxide pigments, have very low laser light transmission, and when the laser output is increased, melting occurs on the laser incident side surface. In some cases, defects such as bubbles due to smoke generation or abnormal heat generation at the bonding interface may occur, or the transmittance may be reduced 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, 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 with a resin, an anthraquinone dye and a monoazo complex dye are used. Laser-light-transmitting colored thermoplastic resin composition containing a laser-transmitting black colorant (Patent Document 2), a thermoplastic resin composition capable of laser-transmission welding using at least two colorants (Patent Document) 3) is disclosed. However, in order to make these all black, two or more kinds of colorants are used, and a complicated toning process is required.
On the other hand, Patent Document 4 describes using a colorant such as anthraquinone, perylene, or methine as a near-infrared absorbing compound. Regarding the resin composition on the transmission side, that is, the laser irradiation side. Has no description or suggestion.

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-mentioned problems, the present inventors have used a purple colorant and a compound having a salicylic acid amide structure in combination, so that black color can be eliminated without going through a complicated toning process. The present inventors have found that a black laser-welded polyester resin composition with excellent welding characteristics can be obtained, and the present invention has been completed.

式（Ｉ）中、Ｒ¹、Ｒ²はそれぞれ、水素原子、ヒドロキシル基、炭素原子数１〜８の直鎖状または分岐状のアルキル基、炭素原子数１〜８のアルコキシ基、炭素原子数６〜１８のアリール基、またはこれらが結合した環状構造（該環状構造の炭素原子数は、縮合環の全炭素原子数として１０〜１８である）を表し、Ｘは単結合または炭素原子数１〜２０のアルキレン基を表し、Ｒは単結合、ｎ価の炭素原子数１〜３０の炭化水素基または複素環基を表し、ｍは０または１である。ｎは１〜３であり、ｎが２以上の場合、Ｒを中心とした構造は対称であっても非対称であってもよく、それぞれのＲ¹、Ｒ²、ｍは同一であっても異なっていてもよい。
（６）（ｄ）サリチル酸アミド構造を有する化合物が、下記式（ＩＩ）で表される化合物である、（５）に記載の黒色レーザー溶着用ポリエステル樹脂組成物。
式（ＩＩ）

式（ＩＩ）中、Ｒ³〜Ｒ⁶はそれぞれ、水素原子、ヒドロキシル基、炭素原子数１〜８の直鎖状または分岐状のアルキル基、炭素原子数１〜８のアルコキシ基または炭素原子数６〜１８のアリール基を表し、Ｒ’は炭素原子数１〜２０の直鎖状のアルキレン基または炭素原子数６〜３０のアリーレン基を表す。
（７）レーザー透過側の部材に用いられる、（１）〜（６）のいずれかに記載の黒色のレーザー溶着用ポリエステル樹脂組成物。
（８）（１）〜（７）のいずれかに記載の黒色のレーザー溶着用ポリエステル樹脂組成物（Ａ）からなる部材とレーザー吸収性を有する樹脂組成物（Ｂ）からなる部材を、前記樹脂組成物（Ａ）からなる部材側からレーザー光を照射して溶着させてなる成形品。
（９）（１）〜（７）のいずれかに記載の黒色のレーザー溶着用ポリエステル樹脂組成物（Ａ）からなる部材とレーザー吸収性を有する樹脂組成物（Ｂ）からなる部材を、該樹脂組成物（Ａ）からなる部材側からレーザー光を照射して溶着させる工程を含む成形品の製造方法。 The present invention has been completed based on the above findings, and the gist is as follows.
(1) (a) 100 parts by weight of a polyester resin, (b) 0 to 100 parts by weight of a reinforcing filler, (c) 0.01 to 1 part by weight of a purple colorant, (d) a compound having a salicylic acid amide structure A black laser-welded polyester resin composition comprising 0.01 to 5 parts by weight.
(2) The black laser welding polyester resin composition according to (1), wherein the molded article having a thickness of 1.5 mm made of the polyester resin composition has a light transmittance of 10% or more at a wavelength of 960 nm.
(3) (a) The polyester resin composition for black laser welding according to (1) or (2), wherein the polyester resin is polybutylene terephthalate.
(4) The black laser welding polyester resin composition according to any one of (1) to (3), wherein the reinforcing filler (b) is a glass fiber.
(5) The black laser welding polyester resin composition according to any one of (1) to (4), wherein the compound having a (d) salicylic acid amide structure is a compound represented by the following formula (I):
Formula (I)

In formula (I), R ¹ and R ² are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and the number of carbon atoms. 6-18 aryl groups, or a cyclic structure in which they are bonded (the number of carbon atoms in the cyclic structure is 10-18 as the total number of carbon atoms in the condensed ring), X is a single bond or 1 carbon atom Represents an alkylene group of ˜20, R represents a single bond, an n-valent hydrocarbon group having 1 to 30 carbon atoms or a heterocyclic group, and m is 0 or 1. n is 1 to 3, and when n is 2 or more, the structure centered on R may be symmetric or asymmetric, and R ¹ , R ² and m may be the same or different. It may be.
(6) The polyester resin composition for black laser welding according to (5), wherein the compound (d) having a salicylic acid amide structure is a compound represented by the following formula (II).
Formula (II)

In formula (II), R ^{3 to} R ⁶ are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or the number of carbon atoms. A 6-18 aryl group is represented, R 'represents a C1-C20 linear alkylene group or a C6-C30 arylene group.
(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 a resin composition (B) having laser absorptivity are used as the resin. A molded article obtained by irradiating and welding a laser beam from the side of a member made of the 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 a resin composition (B) having laser absorptivity, 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 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 polyester 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. The difference in hue (color difference: ΔE) with respect to 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) Two or more polyester resins may be used in combination.
(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.
Two or more of these dicarboxylic acids or derivatives thereof may be used in combination.

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. Polypropylene glycol, polytetramethylene glycol, dibutylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol and 1,8-octanediol can be mentioned as preferred examples.
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-cyclohexanediol. A preferred example is cyclohexanedimethylol.
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.
Two or more of these diols may be used in combination.

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 1: 1 (weight ratio) of tetrachloroethane and phenol. More preferably, it is -1.5 dl / g, and it is further more preferable that it is 0.6-1.3 dl / g. 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 maintained and the molding process becomes easier. . Furthermore, it is good also as an intrinsic viscosity within the said range by using together 2 or more types of PBT resin of intrinsic viscosity.

(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 fibrous, plate-like, and granular reinforcing fillers and mixtures thereof can be used.
Examples of the fibrous reinforcing filler include inorganic fibers such as glass fibers, carbon fibers, silica alumina fibers, zirconia fibers, boron fibers, boron nitride fibers, silicon nitride fibers, potassium titanate fibers, metal fibers, and aromatic polyamides. Examples thereof include organic fibers such as fibers and fluorine resin fibers.
Examples of the plate-like reinforcing filler include glass flake, mica (mica), talc, wollastonite, and metal foil.
Examples of the particulate reinforcing filler include ceramic beads, clay, zeolite, kaolin, potassium titanate, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, and magnesium hydroxide.
In the present invention, among the reinforcing fillers (b), fibrous reinforcing fillers are 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, further preferably 3 to 30 μm, and more preferably 5 to 20 μm. Particularly 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 reinforcing filler is more effectively expressed, and by making the average fiber length 20 mm or less, (a) melt kneading with the polyester resin And the molding of the reinforced 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 aminosilane, epoxysilane, allylsilane, and vinylsilane. 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 treatment agent used for the reinforcing filler, a combination of an aminosilane-based coupling agent and a novolac type epoxy resin is particularly preferable. By configuring the surface treatment agent in this way, the inorganic functional group of the aminosilane coupling agent is (b) the reinforcing filler surface, the organic functional group of the aminosilane coupling agent is the glycidyl group of the epoxy resin, and the epoxy The glycidyl group of the resin is rich in reactivity with the (a) polyester resin, and the interfacial adhesion between (b) the reinforcing filler and (a) the polyester resin is improved. As a result, the mechanical properties and hydrolysis resistance of the 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 tends to be 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 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 these, glass having a refractive index of preferably 1.550 to 1.600, more preferably a refractive index of 1.560 to 1.600 can be used. The glass having a refractive index of 1.560 to 1.600 is usually composed of MgO, excluding B ₂ O ₃ and F ₂ components from the constituent components of E glass (refractive index of 1.550) used for polyester resins. By increasing the proportion of components such as TiO ₂ and ZnO, and employing this glass, the laser transmittance of the resin composition of the present invention can be further improved.
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, more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the (a) polyester resin. . When the blending amount is 100 parts by weight or less, it tends to suppress the floating of the reinforcing filler to the surface of the molded product, and the weldability at the laser welding interface can be more effectively improved, which is preferable.

<(C) Purple colorant>
In the polyester resin of the present invention, (c) a purple colorant is blended. In the present invention, since one colorant can be used, complicated toning is unnecessary, and the toning process can be reduced and economical. Of course, addition of other colorants is not excluded without departing from the spirit of the present invention.

The purple colorant is classified according to the Color Index and is represented by Violet. For example, methine dyes with high heat resistance (CI Solvent Violet 49), anthraquinone dyes (CI Solvent Violet 13, CI Solvent Violet 36, CI Solvent Violet 37), and perylene dyes (CIPigment Violet 29) are preferable examples. . Of these colorants, methine dyes are preferred. 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 It is.
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 methine dyes, those having good heat resistance and ultraviolet aging resistance and low sublimation properties are preferred, and CI Solvent Violet 49, which has excellent ultraviolet aging resistance, is particularly preferred.

  The blending amount of the (c) purple colorant of the present invention is 0.01 to 1 part by weight, preferably 0.03 to 0.8 part by weight, based on 100 parts by weight of the (a) polyester resin. More preferably, it is 0.05-0.5 weight part. (C) By making the blending amount of the purple colorant 0.01 parts by weight or more, the resin composition can be given a black hue, and sufficient heat resistance and UV aging resistance can be imparted. When the amount is 1 part by weight or less, the dispersibility in the polyester resin is good, and bleeding out to the surface of the molded product and reduction in mechanical strength are suppressed, which is preferable.

<(D) Compound having salicylic acid amide structure>
In the resin composition of the present invention, in order to make the resulting resin composition black, (c) a compound having a salicylic acid amide structure is blended together with a purple colorant. (D) The compound having a salicylic acid amide structure is not particularly defined, but preferably has a molecular weight of 180 to 800 in order to give sufficient black color to the resulting resin composition. More preferred is ~ 800. In addition, the compound (d) having a salicylic acid amide structure is preferably a compound having a melting point of 50 to 350 ° C. from the viewpoints of resin composition production, handling at the time of molding, and dispersibility in the resin composition.
The compound (d) having a salicylic acid amide structure employed in the present invention is preferably compatible with the polyester resin and excellent in heat resistance. Specific examples include compounds represented by the following formula (I). . All of these compounds are white powders.

式（Ｉ）中、Ｒ¹、Ｒ²はそれぞれ、水素原子、ヒドロキシル基、炭素原子数１〜８の直鎖状または分岐状のアルキル基、炭素原子数１〜８のアルコキシ基、炭素原子数６〜１８のアリール基、またはこれらが結合した環状構造（該環状構造の炭素原子数は、縮合環の全炭素原子数として１０〜１８である）を表し、Ｘは単結合または炭素原子数１〜２０のアルキレン基を表し、Ｒは単結合、ｎ価の炭素原子数１〜３０の炭化水素基または複素環基を表し、ｍは０または１である。ｎは１〜３であり、ｎが２以上の場合、Ｒを中心とした構造は対称であっても非対称であってもよく、それぞれのＲ¹、Ｒ²、ｍは同一であっても異なっていてもよい。 Formula (I)

In formula (I), R ¹ and R ² are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and the number of carbon atoms. 6-18 aryl groups, or a cyclic structure in which they are bonded (the number of carbon atoms in the cyclic structure is 10-18 as the total number of carbon atoms in the condensed ring), X is a single bond or 1 carbon atom Represents an alkylene group of ˜20, R represents a single bond, an n-valent hydrocarbon group having 1 to 30 carbon atoms or a heterocyclic group, and m is 0 or 1. n is 1 to 3, and when n is 2 or more, the structure centered on R may be symmetric or asymmetric, and R ¹ , R ² and m may be the same or different. It may be.

In formula (I), when the ring structure R ¹ and R ² are bonded is not particularly limited as long as R ¹ and R ² of the bonding to each form a cyclic, R ¹ and R ² bond Examples of the condensed ring structure with the benzene ring are those formed by forming a structure such as 2,3-dihydroidene, indene, 1,2,3,4, -tetrahydronaphthalene, naphthalene and the like.

  Examples of the compound represented by the above formula (I) include compounds represented by the following formulas (III) to (VI).

Formula (III)

Formula (IV)

Formula (V)

式（ＶＩ）中、Ｙ¹、Ｙ²はそれぞれ、水素原子、メチル基またはメトキシ基を表し、Ｙ³は水素原子またはヒドロキシル基を表す。 Formula (VI)

In formula (VI), Y ¹ and Y ² each represent a hydrogen atom, a methyl group or a methoxy group, and Y ³ represents a hydrogen atom or a hydroxyl group.

  Among the compounds represented by the above formula (I), a compound represented by the following formula (II) is more preferable in terms of excellent dispersibility in a polyester resin, and a compound having a high molecular weight is particularly preferable.

式（ＩＩ）中、Ｒ³〜Ｒ⁶はそれぞれ、水素原子、ヒドロキシル基、炭素原子数１〜８の直鎖状または分岐状のアルキル基、炭素原子数１〜８のアルコキシ基または炭素原子数６〜１８のアリール基を表し、Ｒ’は炭素原子数１〜２０の直鎖状のアルキレン基または炭素原子数６〜３０のアリーレン基を表す。 Formula (II)

In formula (II), R ^{3 to} R ⁶ are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or the number of carbon atoms. A 6-18 aryl group is represented, R 'represents a C1-C20 linear alkylene group or a C6-C30 arylene group.

The compounding amount of the compound having the (d) salicylic acid amide structure is 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, further preferably 100 parts by weight of the (a) polyester resin. 0.1 to 1 part by weight.
(D) By making the compounding quantity of the compound which has a salicylic acid amide structure into 0.01 weight part or more, a black hue can be given to the resin composition obtained, and polyester resin is made into 5 weight part or less. It is preferable because the dispersibility in the resin can be improved, and the decrease in mechanical strength can be suppressed. In addition, the compound (d) having a salicylic acid amide structure of the present invention also has a heavy metal inactive effect, for example, (a) it is possible to prevent deterioration of the resin due to a trace heavy metal derived from a polymerization catalyst contained in the polyester resin. It is.

<Other additives>
You may mix | blend another additive with the resin composition of this invention in the range which does not deviate from the meaning of this invention. Examples of other additives include antioxidants, heat stabilizers, flame retardants, crystal nucleating agents, lubricants, mold release agents, and catalyst deactivators. These additives can be added when preparing the resin composition of the present invention during (a) polymerization of the polyester resin or after polymerization of the 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 resin composition of the present invention more effectively and further improving the retention of mechanical properties 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- Til-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. Examples thereof include a hindered phenol-based antioxidant. In particular, hindered phenolic 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 its upper limit is usually 3000.

The sulfur-based antioxidant in the present invention refers to an antioxidant containing 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 Examples include isopropyl 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 polyester resin composition of the present invention, the 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 As a result, it is possible to prevent the resin from being lowered, and it is possible to make the decomposition of the resin during the melt-kneading less likely to occur.

  As the heat stabilizer, those having the effect of more effectively improving the heat stability during residence of the resin composition of the present invention and further suppressing the deterioration of the color tone and mechanical properties are preferred. Examples of the heat stabilizer include an organic phosphorus compound, and an organic phosphate compound, an organic phosphite compound, an organic phosphonite compound, and the like are preferable, and an organic phosphate compound is more preferable. Two or more organic phosphorus compounds may be used in combination. As the organic phosphate compound, a long-chain dialkyl acid phosphate compound represented by the following formula (VII) is preferable because of excellent heat stability.

式（ＶＩＩ）中、Ｒ⁷およびＲ⁸は、各々独立して、炭素原子数８〜３０のアルキル基を表す。 Formula (VII)

In formula (VII), R ⁷ and R ⁸ each independently represents an alkyl group having 8 to 30 carbon atoms.

Specific examples of the alkyl group having 8 to 30 carbon atoms represented by R ⁷ or R ⁸ in the above formula (VII) include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group. Group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, triacontyl group, and the like. Among them, those having 12 to 25 carbon atoms, more preferably 15 to 20 carbon atoms are preferable.

  Specific examples of the long-chain dialkyl acid phosphate compound represented by the above formula (VII) include dioctyl phosphate, di (2-ethylhexyl) phosphate, diisooctyl phosphate, dinonyl phosphate, diisononyl phosphate, didecyl phosphate, diisodecyl. Examples include phosphate, dodecyl phosphate, ditridecyl phosphate, diisotridecyl phosphate, ditetradecyl phosphate, dihexadecyl phosphate, dioctadecyl phosphate, dieicosyl phosphate, and ditriacontyl phosphate. Of these, ditetradecyl phosphate, dihexadecyl phosphate, and dioctadecyl phosphate are preferable.

  The compounding amount of the organophosphorus compound is, for example, 0.01 to 1 part by weight, more preferably 0.05 to 0.5 part by weight, and particularly 0.08 to 0.3 part per 100 parts by weight of the polyester resin. It is preferable that it is a weight part. By making the blending amount of the organophosphorus compound 0.01 parts by weight or more, there is a tendency that the effect of improving the thermal stability during heating and staying tends to be exhibited more easily. By making the blending amount 1 part by weight or less , It tends to be less likely to adversely affect performance other than thermal stability during heating and residence.

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. Two or more of these flame retardants may be used in combination.
The blending amount of the flame retardant is preferably 0.1 to 50 parts by weight, more preferably 1 to 30 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. Thermosetting resins such as polyamide resins, polyphenylene sulfide resins, polyacetal resins, polyphenylene oxide resins, etc. (a) thermoplastic resins other than polyester resins, epoxy resins, phenol resins, melamine resins, silicone resins, etc. can be blended. . 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.

  The black laser-welded polyester resin composition of the present invention preferably has a thickness of 1.5 mm and a light transmittance of 10% or more at a wavelength of 960 nm of a molded product having a thickness of 1.5 mm. More preferably.

  The method for producing the resin composition of the present invention is not particularly limited, but a method of using a uniaxial or biaxial extruder having equipment capable of devolatilization from a vent port as a kneader is preferable. The above (a) polyester resin, (c) purple colorant, (d) each component of the compound having a salicylic acid amide structure and, if necessary, (b) reinforcing filler and other additives are put together in a kneader. Or (a) other blending components may be sequentially supplied to the polyester resin. (B) When the reinforcing filler is blended, it is desirable to supply the reinforcing filler from the middle of the extruder in order to prevent the reinforcing filler from being crushed during kneading. 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 purple colorant more than a predetermined blending ratio in part of a polyester resin is prepared in advance, and this is melt-mixed and extruded with the remaining blending components to a predetermined blending ratio. By doing so, the resin composition in the present invention can be obtained.

  The method for producing a molded article using the resin composition of the present invention is not particularly limited, and molding methods generally used for thermoplastic resins, that is, molding methods such as injection molding, hollow molding, extrusion molding, press molding, and the like. 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 resin composition of the present invention is suitable for a black laser welding polyester resin material. In particular, by using the resin composition of the present invention for one or both of the two members, the members can be firmly bonded to each other by laser welding. Therefore, the black laser welding polyester resin composition of the present invention can be preferably used for the production of a molded article having two or more resin members.
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. The resin composition of the present invention can be preferably used as a member that transmits laser light because it is highly permeable to laser light despite being colored. 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 resin composition (A) of the present invention and a member made of the resin composition (B) having laser absorption, first, the welded portions of the two are mutually connected. Contact. 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 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 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 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 together, and includes a member that forms a part of the finished product and parts.

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 resin composition (A) of the present invention. The resin contained in the resin composition (B) is preferably a thermoplastic resin, for example, olefin resin, vinyl resin, styrene resin, acrylic resin, polyester resin, polyamide resin, polycarbonate resin, polyacetal resin. From the viewpoint of good compatibility, polyester resins, polyamide resins, and polycarbonate resins are particularly preferably used. Moreover, the resin composition (B) may be comprised from 1 type, or 2 or more types of resin. Furthermore, the resin composition (A) of the present invention may be used.
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 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 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, office automate (OA) equipment. It can be applied to 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 Each resin composition described in Table 1 is manufactured 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. Two types of flat plates each having a size of 13 mm × 128 mm, each having a thickness of 1.5 mm and 2 mm, were formed.
The light transmittance of each of these flat plates was measured with a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation: UV-3100PC). The light transmittance was expressed as a percentage of the ratio of transmitted light intensity and incident light intensity in the near infrared region 960 nm.

(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. 1 shows a test piece prepared in (1), 2 shows a test piece made of a resin composition (B) which is a mating material to be joined (made in the same manner as (1)), and 3 shows a laser irradiation location, respectively. ing.

(1) The test piece 1 (13 mm × 128 mm, 2 mm thick flat plate) used in the light transmittance measurement is the laser transmission side, and the test piece 2 made of the resin composition (B) described later is the laser absorption side. The test pieces were stacked and irradiated with laser from the transmission side. As a laser welding apparatus, a batch irradiation type IRAM-300 manufactured by Nippon Emerson Co., Ltd. was used, and laser irradiation was performed under the conditions of a laser beam wavelength of 960 nm, a welding spot of 3 mm × 6 mm, and a pressure of 4.8 MPa. The laser irradiation time was 13 sec when the test piece 1 did not contain the reinforcing filler, and 17 sec when the specimen 1 contained the reinforcing filler.
Laser welding strength is measured by using a tensile tester (type 5544 manufactured by Instron Corp.). The test pieces 1 and 2 which are integrated by welding are clamped at both ends in the major axis direction, and the tensile speed is 5 mm. Evaluation was performed by pulling at / sec. The laser welding strength is indicated by the tensile shear fracture strength of the welded portion.

(3) Blackness (a1) To 100 parts by weight of the polybutylene terephthalate resin, (c3) 0.6 parts by weight of carbon black is blended, and a resin composition is produced by the same production method as in Example 1 described later. (1) A flat plate having a size of 13 mm × 128 mm and a thickness of 2 mm 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 the black standard.
The hue of a flat plate having a thickness of 2 mm for measuring light transmittance (1) obtained by injection molding of each resin composition 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 according to the following equation.
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: manufactured by Mitsubishi Engineering Plastics Co., Ltd., “trade name: NOVADURAN (registered trademark) 5020”, intrinsic viscosity [η] = 1.20 dl / g

(B) Reinforcing filler (b1) E glass fiber: Chopped strand treated with a surface treatment agent, manufactured by Nippon Electric Glass Co., Ltd., “trade name: ECS03T-187”, fiber diameter 13 μm, cut length (fiber length) 3 mm , Refractive index (nd) 1.555
(B2) High refractive index glass fiber: Chopped strand treated with a surface treatment agent, manufactured by Asahi Fiber Glass Co., Ltd., average fiber diameter 15 μm, cut length (fiber length) 3 mm, refractive index (nd) 1.585

(C) Colorant (c1) Methine dye: C.I. I. Solvent Violet 49, manufactured by Clariant, "Product name: Polysynthren Violet G"
(C2) Anthraquinone dyes: C.I. I. Solvent Violet 36, manufactured by LANXESS, "Product name: Macrolex Violet 3R"
(C3) Carbon black: “Product name: MA600B” manufactured by Mitsubishi Chemical Corporation

(D): Compound having salicylic acid amide structure: Compound represented by the following formula (III), manufactured by ADEKA, “trade name: ADK STAB CDA-6”

Formula (III)

 Antioxidant: Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], “trade name: Irganox 1010”, molecular weight 1178, manufactured by Ciba Specialty Chemicals.

[Resin composition (B)]
A resin composition of Comparative Example 4 described later was used by blending 0.6 part by weight of (c3) carbon black with respect to 100 parts by weight of (a1) polybutylene terephthalate.

[Examples 1-4, Comparative Examples 1-4]
The ratio shown in Table 1 for the polybutylene terephthalate resin of (a1) and / or (a2), the colorant of any of (c1) to (c3), (d) the compound having a salicylic acid amide structure, and the antioxidant And mixed with a tumbler for 20 minutes. Using a twin-screw extruder (manufactured by Nippon Steel Works: TEX30C, barrel 9 block configuration) with the cylinder temperature set to 250 ° C., the obtained raw material mixture was supplied to a hopper and melt-kneaded. When blending the reinforcing filler (b1) or (b2), it was fed 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 using the purple colorant of (c1) or (c2) as the colorant and further blending (d) a compound having a salicylic acid amide structure, the color is black, and It became clear that a resin composition excellent in laser permeability and laser weldability can be obtained. By using the resin composition of the present invention, strong laser welding with other members can be easily performed. Furthermore, in the present invention, since only one colorant is used, complicated toning is unnecessary, and the toning process can be reduced and economical.

Since the polyester resin composition of the present invention is excellent in laser transmission and laser welding characteristics, it can be suitably used particularly for components for sealing electrical circuits such as vehicle electrical components, sensor components, and connector components. It is.
In addition, by using the resin composition of the present invention, the range of product thickness that can be welded is widened and the degree of freedom in product design can be increased, and further, the range of laser welding conditions such as laser irradiation intensity and scanning speed can be increased. It is also possible to provide a molded product in which members are bonded more firmly. Such molded articles are widely used industrially and their 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) 0 to 100 parts by weight of a reinforcing filler, (c) 0.01 to 1 part by weight of a purple colorant, and (d) a compound 0.01 having a salicylic acid amide structure with respect to 100 parts by weight of a polyester resin. A black laser-welded polyester resin composition comprising ~ 5 parts by weight. 2. The black laser-welded polyester resin composition according to claim 1, wherein a 1.5 mm-thick molded article made of the polyester resin composition has a light transmittance of 10% or more at a wavelength of 960 nm. (A) The polyester resin composition for black laser welding according to claim 1 or 2, wherein the polyester resin is polybutylene terephthalate. (B) The black laser welding polyester resin composition according to any one of claims 1 to 3, wherein the reinforcing filler is glass fiber. (D) The black laser welding polyester resin composition according to any one of claims 1 to 4, wherein the compound having a salicylic acid amide structure is a compound represented by the following formula (I).
Formula (I)

In formula (I), R ¹ and R ² are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and the number of carbon atoms. 6-18 aryl groups, or a cyclic structure in which they are bonded (the number of carbon atoms in the cyclic structure is 10-18 as the total number of carbon atoms in the condensed ring), X is a single bond or 1 carbon atom Represents an alkylene group of ˜20, R represents a single bond, an n-valent hydrocarbon group having 1 to 30 carbon atoms or a heterocyclic group, and m is 0 or 1. n is 1 to 3, and when n is 2 or more, the structure centered on R may be symmetric or asymmetric, and R ¹ , R ² and m may be the same or different. It may be. (D) The polyester resin composition for black laser welding according to claim 5, wherein the compound having a salicylic acid amide structure is a compound represented by the following formula (II).
Formula (II)

In formula (II), R ^{3 to} R ⁶ are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or the number of carbon atoms. A 6-18 aryl group is represented, R 'represents a C1-C20 linear alkylene group or a C6-C30 arylene group. 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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