JP6894093B2 - Laser welding resin composition and its welded material - Google Patents

Description

The present invention relates to a laser welded resin composition and a welded body, and a welded body obtained by laser welding a molded product obtained from the laser welded resin composition has high welding strength and black coloring power. It is a laser-welded polyester resin composition that is high and has excellent laser welding processability.

Thermoplastic polyester resin is widely used for various equipment parts because it has excellent mechanical strength, chemical resistance, electrical insulation, etc., and also has excellent heat resistance, moldability, and recyclability. Has been done.
In recent years, in particular, automobile parts have been reduced in weight, and in many cases, a high level of heat resistance is required due to resinification of parts that conventionally used metal and miniaturization of resin products. Therefore, reinforced thermoplastic resins containing fillers such as glass fiber are often used. Among them, thermoplastic polyester resins such as polybutylene terephthalate have excellent mechanical strength and moldability, and are used for automobile electronic parts cases, motor parts housings, etc. Widely used in.

Recently, the number of cases of welding is increasing in order to improve productivity efficiency, and among them, laser welding, which has less influence on electronic parts, has been widely used.
However, compared to polycarbonate resins, polystyrene-based resins, etc., polyester resins have relatively low laser light transmittance, and the molded products tend to warp, so that the welding strength is often insufficient.
When the molded product is warped, a method of applying a pressing force to correct the warp at the time of welding is also adopted, but it is often difficult to apply the pressing force efficiently depending on the shape of the molded product, and welding is also performed. Since residual stress remains in the welded body from which the pressing force is removed later, there is a problem that it is difficult to obtain high welding strength.

A method of using a copolymer polybutylene terephthalate to improve the laser weldability of a polyester resin (Patent Document 1), a method of alloying a polycarbonate resin or a styrene resin with polybutylene terephthalate (Patent Documents 2 and 3). Further, a method of adding a specific oligomer (Patent Document 4) and the like have been proposed.
However, with these methods, sufficient weldability may not be obtained due to gaps between the welded members caused by warpage deformation of the molded product or the like.
Further, a method of adding a laser transmission absorber such as niglosin to a thermoplastic resin to improve the weldability (Patent Document 5) has also been proposed, but a polyester resin composition suitable for laser welding has been described. Absent.

Japanese Patent No. 3510817 Japanese Unexamined Patent Publication No. 2003-292752 Japanese Patent No. 4461377 Japanese Unexamined Patent Publication No. 2004-315805 Japanese Unexamined Patent Publication No. 2008-1112

An object of the present invention is to provide a laser welded polyester resin composition having excellent laser welding processability, black coloring power, and excellent welding strength of a welded body obtained by laser welding.

The present inventors have stated that the above problems can be solved by using a thermoplastic polyester resin material containing a polybutylene terephthalate homopolymer and / or a polybutylene terephthalate copolymer in combination with niglosin, a specific colorant, and a plasticizer. The heading has reached the present invention.
The present invention relates to the following laser welded resin compositions, laser welded molded articles and laser welded bodies.

[1] A resin composition used for welding by laser light.
(A) With respect to 100 parts by mass of a thermoplastic polyester resin material containing a polybutylene terephthalate homopolymer and / or a polybutylene terephthalate copolymer.
(B) Niglosin 0.0005 to 0.5 parts by mass,
(C) 0.01 to 2 parts by mass of colorant containing anthraquinone dye, and
(D) A laser welding resin composition containing 0.01 to 5 parts by mass of a plasticizer.

[2] The colorant is a perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm and an anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, and the mass ratio C2 / C1 of both is 0. . The laser welding resin composition according to the above [1], which is a colorant contained in a ratio of 4 to 2.
[3] (A) The thermoplastic polyester resin material contains a polybutylene terephthalate homopolymer and a polybutylene terephthalate copolymer, and the content of the polybutylene terephthalate copolymer is 5 to 95% by mass based on 100% by mass of the total of both. %. The laser-welded resin composition according to the above [1] or [2].
[4] (A) The thermoplastic polyester resin material contains a polybutylene terephthalate homopolymer and a polyethylene terephthalate resin, and the content of the polyethylene terephthalate resin is 5 to 50% by mass with respect to a total of 100% by mass of both. The laser-welded resin composition according to any one of the above [1] to [3].
[5] (A) The thermoplastic polyester resin material contains a polybutylene terephthalate homopolymer and a polycarbonate resin, and the content of the polycarbonate resin is 5 with respect to a total of 100% by mass of the polybutylene terephthalate homopolymer and the polycarbonate resin. The laser welding resin composition according to the above [1] or [2], which is ~ 50% by mass.
[6] The laser welding resin composition according to any one of the above [1] to [5], wherein the plasticizer is at least one selected from an aromatic polyunsaturated carboxylic acid ester and an acrylic polymer.

[7] Any of the above [1] to [6], wherein the absorbance a (absorbance converted to a 1 mm thick molded plate) of the molded plate made of the resin composition with respect to 940 nm laser light is 0.05 to 1. The laser welding resin composition described in Crab.
[8] The above-mentioned [1] to [7], wherein the incident rate K (incident rate converted into a molded plate having a thickness of 1 mm) of the molded plate made of the resin composition with respect to the laser beam of 940 nm is 20 to 80%. The laser welding resin composition according to any one.
However, the incident rate K (%) = 100-transmittance-reflectance.

[9] A laser welding molded article comprising the laser welding resin composition according to any one of the above [1] to [8].
[10] The laser welded body of the molded product according to the above [9].
[11] The laser welded body according to the above [10], wherein the welded body has a gap of 0.1 mm or more when welded at least in a part of the welded portion.
[12] The laser welded body according to the above [10] or [11], wherein the molded bodies are butt welded to each other.
[13] The laser welded body according to the above [10] or [11], wherein the molded bodies are superposed and welded to each other.

The laser welding resin composition of the present invention has excellent black coloring power and suitable laser welding processability, and a welded body obtained by laser welding a molded body of the resin composition is excellent in welding strength and black coloring property.

FIG. 1 is an ultraviolet-visible spectroscopic spectrum diagram of each dye used in Production Example 1 of a colorant. FIG. 2 is a diagram showing an example of an implementation in which a plurality of molded bodies are butted against each other and a laser welded body is manufactured by laser welding. FIG. 3 is a diagram showing an example of an implementation in which a plurality of molded bodies are superposed and a laser welded body is manufactured by laser welding. FIG. 4 is a conceptual diagram showing a method of butt laser welding in an example.

Hereinafter, embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these embodiments. In the specification of the present application, "~" is used to mean that the numerical values described before and after the value are included as the lower limit value and the upper limit value.

The laser welding resin composition of the present invention
A resin composition used for welding by laser light.
(A) With respect to 100 parts by mass of a thermoplastic polyester resin material containing a polybutylene terephthalate homopolymer and / or a polybutylene terephthalate copolymer.
(B) Niglosin 0.0005 to 0.5 parts by mass,
(C) 0.01 to 2 parts by mass of colorant containing anthraquinone dye, and
(D) It is characterized by containing 0.01 to 5 parts by mass of a plasticizer.

[(B) Nigrosin]
The laser welding resin composition of the present invention contains (B) niglosin.
Niglosin acts as a dye having laser light absorption, and has a gentle absorption in the range of laser light of 800 nm to 1200 nm.
Nigrosin is described in C.I. I. Solvent Black 5 and C.I. I. Solvent Black 7 is a black azine-based condensation mixture as described in Color Index. This can be synthesized, for example, by oxidizing and dehydrating and condensing aniline, aniline hydrochloride and nitrobenzene in the presence of iron chloride at a reaction temperature of 160 to 190 ° C. Examples of commercially available products of niglocin include "NUBIAN (registered trademark) BLACK series" (trade name, manufactured by Orient Chemical Industries Co., Ltd.) and the like.

The content of (B) niglocin is 0.0005 to 0.5 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material, and 0.001 is a suitable condition for controlling the calorific value. It is ~ 0.1 parts by mass, more preferably 0.003 to 0.05 parts by mass, and further preferably 0.005 to 0.03 parts by mass.
The above content is determined when the (A) thermoplastic polyester resin material described later also contains a resin other than the thermoplastic polyester resin, a polycarbonate resin, and / or an aromatic vinyl resin and the like. This is the amount based on 100 parts by mass of the total resin including the resin.

By adjusting the content of niglocin in such a range, it is possible to balance the transmittance and the reflectance of the molded product. In the present invention, it is defined as the incident rate.
The incident rate K (incident rate converted to a molded plate having a thickness of 1 mm) of the laser welding resin composition is preferably 20 to 80%, more preferably 25 to 75%, and particularly preferably 30 to 70%. it can. Further, by blending niglocin, it is possible to improve the black coloring power, the surface appearance and smoothness of the molded product, and the laser weldability is improved.
The incident rate K (unit:%) is defined by the following formula.
Incident rate K (%) = 100-transmittance-reflectance The incident rate K is the incident rate of the molded product at a thickness of 1 mm with respect to a laser beam having a wavelength of 940 nm.
In the case of the ASTM4 dumbbell (1 mm) molded body, it is derived from the measurement results of the transmittance and reflectance of the part on the opposite side of the gate (the part on the opposite side of the gate in which the resin is injected). Incidentally, the molded body is a cylinder temperature of 255 ° C., a mold temperature of 65 ° C., injection speed 100 mm / sec, an injection rate which will be described later ^{(injection rate) 66cm 3 / sec} , below which surface progression factor (surface progression factor) 880cm ³ Manufactured under the condition of / sec · cm. In addition, the laser welding resin composition may contain other absorbent dyes or laser light absorbers for laser light within an effective range in which the present invention can be carried out.

[(C) Colorant]
As the colorant (C) used in the laser welding resin composition of the present invention, one containing an anthraquinone dye is used.
Further, the colorant (C) contains a perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm and an anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, and the mass ratio C2 / C1 of both is 0. . It is preferable that the colorant is contained in a ratio of 4 to 2.
More preferably, the anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, the perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm, and the anthraquinone dye C3 having a maximum absorption wavelength in the range of 435 to 455 nm. May be used together. The mass ratio of the anthraquinone dye C1, the perinone dye C2, and the anthraquinone dye C3, which are the dyes, to 100 parts by mass in total is preferably C1: C2: C3 = 24 to 42:24 to 48:22 to 46.
The maximum absorption wavelength is defined as the wavelength showing the maximum absorption in the absorption spectrum obtained by measuring the solution dissolved in dimethylformamide (DMF) using an ultraviolet-visible spectrophotometer.

The colorant of the present invention will be described in detail.
The colorant (C) has absorption in the visible region, (A) has good compatibility with the thermoplastic polyester resin material, and requires a combination of dyes having low scattering characteristics with respect to laser light, and is required during resin molding. It is desirable that it does not easily fade even when exposed to high temperatures during melting and has excellent heat resistance.
The anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, which is preferably used as the (C) colorant of the present invention, is usually a blue oil-soluble dye. In the present invention, by using this dye, for example, the visibility is higher than that of the green anthraquinone dye, and even when a black mixed dye is combined, the coloring power is high by combining the red dye and the yellow dye by the reduced color mixing. A colorant showing a black color can be obtained.

As the anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, it is preferable to select a dye C1 having a measured value (decomposition start temperature) of a thermogravimetric analyzer TG / DTA in the presence of air of 300 ° C. or higher.
Preferred anthraquinone dyes C1 are C.I. I. Solvent Blue 97 (decomposition start temperature 320 ° C.), C.I. I. Examples thereof include Solvent Blue 104 (decomposition start temperature 320 ° C.). They may be used alone or in combination of two or more. However, when the blending amount is large, it becomes easy to bleed from the molded product in a high temperature atmosphere, and the heat-resistant discoloration characteristics tend to deteriorate.
Examples of the commercially available anthraquinone dye C1 include "NUBIAN (registered trademark) BLUE series" and "OPLAS (registered trademark) BLUE series" (both trade names, manufactured by Orient Chemical Industries Co., Ltd.).

In the present invention, as the (C) colorant, preferably, a perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm is used in combination with the anthraquinone dye C1 described above. These are usually red oil-soluble dyes. Specific examples of such a perinone dye C2 include C.I. I. Solvent Red 135, 162, 178, 179 and the like can be used. They may be used alone or in combination of two or more. However, when the blending amount is large, it becomes easy to bleed from the molded product in a high temperature atmosphere, and the heat-resistant discoloration characteristics tend to deteriorate.
Examples of commercially available products of the red perinone dye C2 include "NUBIAN (registered trademark) RED series and OPLAS (registered trademark) RED series" (both of which are trade names manufactured by Orient Chemical Industries Co., Ltd.).

Further, in the present invention, in addition to the above-mentioned dyes C1 and C2, it is also preferable to use an anthraquinone dye C3 having good heat resistance in the range of the maximum absorption wavelength of 435 to 455 nm in combination. The anthraquinone dye C3, which has a maximum absorption wavelength in the range of 435 to 455 nm, is usually a yellow oil-soluble dye.
Specific examples of the anthraquinone dye C3 having a maximum absorption wavelength in the range of 435 to 455 nm include C.I. I. Solvent Yellow 163, C.I. I. Bat Yellow 1, 2, 3, etc. can be used. They may be used alone or in combination of two or more. However, when the blending amount is large, it becomes easy to bleed from the molded product in a high temperature atmosphere, and the heat-resistant discoloration characteristics tend to deteriorate.
Examples of commercially available products of the yellow anthraquinone dye as such anthraquinone dye C3 include "NUBIAN (registered trademark) YELLOW series, OPLAS (registered trademark) YELLOW series" (both trade names, manufactured by Orient Chemical Industry Co., Ltd.). Can be mentioned.

The colorants (C) used in the present invention include anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm, and a maximum absorption wavelength of 435 to 455 nm. It is preferable to use the anthraquinone dye C3 in the range of (B), but the hue of the oil-soluble dye constituting (B) niglocin and (C) the colorant changes depending on the compatibility with the polybutylene terephthalate homopolymer, so that the hue is black. In order to obtain a jet-black molded plate suitable for (C), it is necessary to adjust the proportion of the oil-soluble dye constituting the colorant. Therefore, the content ratio of C1 to C3 is preferably C1: C2: C3 = 24 to 42:24 to 48:22 to 46 in terms of mass ratio (based on a total of 100 parts by mass of C1, C2, and C3). A more preferable ratio of C1: C2: C3 is 24 to 41:24 to 39:22 to 46.

Further, in the present invention, the colorant (C) comprises a perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm and an anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, and a mass ratio of both C2 / C1. It is preferable that the colorant is contained in a proportion of 0.4 to 2. Considering the color development property of the resin composition of the present invention and the suppression of bleed-out, it is more preferably 0.4 to 1.5, still more preferably 0.6 to 1.5.

The content of the (C) colorant is 0.01 to 2 parts by mass, preferably 0.05 to 0.8 parts by mass, and more preferably 0.05 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material. 0.1 to 0.6 parts by mass. By adjusting the content of the colorant within such a range, a laser welding resin composition having a high black coloring power can be obtained.

In the present invention, the colorant (C) may contain dyes other than the above-mentioned C1, C2 and C3, but preferably does not contain a nickel complex.
Other dyes that may be used in combination include azo dyes, quinacridone dyes, dioxazine dyes, quinophthalone dyes, perylene dyes, perinone dyes (compounds having a wavelength different from C2 described above), isoindolinone dyes, triphenylmethane dyes, and anthraquinones. Examples thereof include dyes such as dyes (compounds having wavelengths different from those of C1 and C3 described above).

[(A) Thermoplastic polyester resin material]
The (A) thermoplastic polyester-based resin material contained in the laser-welded resin composition of the present invention contains a polybutylene terephthalate homopolymer (A1a) and / or a polybutylene terephthalate copolymer (A1b), which includes a polycarbonate resin (A1b). It may further contain at least one of A2a) or a polyethylene terephthalate resin (A2b).

<Polybutylene terephthalate homopolymer (A1a)>
The polybutylene terephthalate homopolymer (A1a) used in the (A) thermoplastic polyester resin material of the present invention is a polymer obtained by polycondensing terephthalic acid as an acid component and 1,4-butanediol as an alcohol component. Is.

The intrinsic viscosity of the polybutylene terephthalate homopolymer (A1a) is preferably 0.5 to 2 dl / g. From the viewpoint of moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are more preferable. If an intrinsic viscosity of less than 0.5 dl / g is used, the obtained welding member tends to have low mechanical strength. If the value is higher than 2 dl / g, the fluidity of the (A) thermoplastic polyester resin material may be deteriorated, the moldability may be deteriorated, or the laser weldability may be lowered.
The intrinsic viscosity is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

The amount of terminal carboxyl groups of the polybutylene terephthalate homopolymer (A1a) may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and 30 eq / ton or less. Is even more preferable. If it exceeds 50 eq / ton, gas is likely to be generated during melt molding of the (A) thermoplastic polyester resin material. The lower limit of the amount of terminal carboxyl groups is not particularly specified, but is usually 5 eq / ton.

The amount of terminal carboxyl groups of the polybutylene terephthalate homopolymer (A1a) is determined by dissolving 0.5 g of a resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. This is the required value. As a method for adjusting the amount of the terminal carboxyl group, a conventionally known arbitrary method such as a method for adjusting the polymerization conditions such as the raw material charging ratio at the time of polymerization, the polymerization temperature, and the depressurization method, and a method for reacting the terminal sequestering agent can be used. Just do it.

<Polybutylene terephthalate copolymer (A1b)>
(A) The polybutylene terephthalate copolymer (A1b) used for the thermoplastic polyester resin material is preferably isophthalic acid, dimer acid, polytetramethylene glycol (PTMG) in addition to terephthalic acid and 1,4-butanediol. It is a polymer obtained by copolymerizing polyalkylene glycol or the like.

When a polybutylene terephthalate copolymer (A1b) obtained by copolymerizing polytetramethylene glycol is used, the proportion of the tetramethylene glycol component in the copolymer is preferably 3 to 40% by mass, preferably 5 to 30% by mass. % Is more preferable, and 10 to 25% by mass is further preferable. It is preferable to use such a copolymerization ratio because the balance between laser welding property and heat resistance tends to be excellent.

When polybutylene terephthalate copolymerized with dimer acid is used as the polybutylene terephthalate copolymer (A1b), the ratio of the dimer acid component to the total carboxylic acid component is preferably 0.5 to 30 mol% as the carboxylic acid group. , 1-20 mol% is more preferred, and 3-15 mol% is even more preferred. Such a copolymerization ratio tends to have an excellent balance between laser weldability, long-term heat resistance, and toughness, which is preferable.

When isophthalic acid copolymerized polybutylene terephthalate is used as the polybutylene terephthalate copolymer (A1b), the ratio of the isophthalic acid component to the total carboxylic acid component is preferably 1 to 30 mol% as the carboxylic acid group. -20 mol% is more preferred, and 3-15 mol% is even more preferred. Such a copolymerization ratio tends to have an excellent balance between laser welding property, heat resistance, injection moldability and toughness, which is preferable.

Among these copolymers, the polybutylene terephthalate copolymer (A1b) is preferably a copolymerized polybutylene terephthalate obtained by copolymerizing polytetramethylene glycol or an isophthalic acid copolymerized polybutylene terephthalate.

The intrinsic viscosity of the polybutylene terephthalate copolymer (A1b) is preferably 0.5 to 2 dl / g. From the viewpoint of moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are more preferable. If an intrinsic viscosity of less than 0.5 dl / g is used, the obtained resin composition tends to have low mechanical strength. If the value is higher than 2 dl / g, the fluidity of the resin composition may be deteriorated, the moldability may be deteriorated, or the laser weldability may be lowered.
The intrinsic viscosity is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

The amount of the terminal carboxyl group of the polybutylene terephthalate copolymer (A1b) may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and 30 eq / ton or less. It is more preferable to have. If it exceeds 50 eq / ton, gas is likely to be generated during melt molding of the resin composition. The lower limit of the amount of terminal carboxyl groups is not particularly specified, but is usually 5 eq / ton.

The amount of terminal carboxyl groups of the polybutylene terephthalate copolymer (A1b) is a value measured by titration using a 0.01 mol / l benzyl alcohol solution of sodium hydroxide in which 0.5 g of a resin is dissolved in 25 mL of benzyl alcohol. is there. As a method for adjusting the amount of the terminal carboxyl group, a conventionally known arbitrary method such as a method for adjusting the polymerization conditions such as the raw material charging ratio at the time of polymerization, the polymerization temperature, and the depressurization method, and a method for reacting the terminal sequestering agent can be used. Just do it.

In the present invention, when the polybutylene terephthalate homopolymer (A1a) and the polybutylene terephthalate copolymer (A1b) are used in combination as the (A) thermoplastic polyester resin material, the content of the polybutylene terephthalate copolymer (A1b) is (A1a). ) And (A1b) in a total of 100% by mass, the polybutylene terephthalate copolymer (A1b) is preferably 5 to 95% by mass, more preferably 30 to 90% by mass, and further preferably 40 to 90%. It is by mass%, particularly preferably 50 to 90% by mass. When the content of the polybutylene terephthalate copolymer (A1b) is less than 5% by mass, the laser transmittance and the laser welding strength tend to decrease, and when it exceeds 95% by mass, the moldability tends to decrease.

<Polycarbonate resin (A2a)>
(A) The polycarbonate resin (A2a) used for the thermoplastic polyester resin material is obtained by reacting a dihydroxy compound or a small amount of a polyhydroxy compound with a phosgen or a carbonic acid diester, and may be branched. It is a plastic polymer or a copolymer. The method for producing the polycarbonate resin is not particularly limited, and a conventionally known method produced by a phosgene method (interfacial polymerization method) or a melting method (transesterification method) can be used, but the polycarbonate resin is manufactured by the melt polymerization method. Polycarbonate resin is preferable from the viewpoint of laser light transmission and laser welding property.

As the raw material dihydroxy compound, an aromatic dihydroxy compound is preferable, and 2,2-bis (4-hydroxyphenyl) propane (that is, bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, Hydroquinone, resorcinol, 4,4-dihydroxydiphenyl and the like can be mentioned, with preference given to bisphenol A. Further, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

Examples of the polycarbonate resin (A2a) include aromatic polycarbonate resins derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other materials, among the above. Aromatic polycarbonate copolymers derived from aromatic dihydroxy compounds are preferred. Further, it may be a copolymer such as a polymer having a siloxane structure or a copolymer with an oligomer. Furthermore, two or more of the above-mentioned polycarbonate resins may be mixed and used.

The viscosity average molecular weight of the polycarbonate resin (A2a) is preferably 5000 to 30000, more preferably 1000 to 28000, and even more preferably 14000 to 24000. If a material having a viscosity average molecular weight of less than 5000 is used, the obtained welding member tends to have low mechanical strength. If it is higher than 30,000, the fluidity of the resin composition may be deteriorated, the moldability may be deteriorated, or the laser weldability may be lowered.
The viscosity average molecular weight of the polycarbonate resin is the viscosity average molecular weight [Mv] converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent.

The ratio (Mw / Mn) of the polystyrene resin (A2a) to the polystyrene-equivalent mass average molecular weight Mw and the number average molecular weight Mn measured by gel permeation chromatography (GPC) may be 2 to 5. Preferably, 2.5-4 is more preferable. If Mw / Mn is excessively small, the fluidity in the molten state tends to increase and the moldability tends to decrease. On the other hand, if Mw / Mn is excessively large, the melt viscosity tends to increase and molding tends to be difficult.

The amount of terminal hydroxy groups of the polycarbonate resin (A2a) is preferably 100 mass ppm or more, more preferably 200 mass ppm or more, still more preferably 200 mass ppm or more, from the viewpoints of thermal stability, hydrolysis stability, color tone, and the like. It is 400 mass ppm or more, most preferably 500 mass ppm or more. However, it is usually 1500 mass ppm or less, preferably 1300 mass ppm or less, more preferably 1200 mass ppm or less, and most preferably 1000 mass ppm or less. If the amount of terminal hydroxy groups in the polycarbonate resin is excessively small, the laser permeability tends to decrease, and the initial hue at the time of molding may deteriorate. If the amount of terminal hydroxy groups is excessively large, the retention heat stability and the heat resistance to moisture tend to decrease.

(A) When the polybutylene terephthalate homopolymer (A1a) and / or the polybutylene terephthalate copolymer (A1b) and the polycarbonate resin (A2a) are contained together as the thermoplastic polyester resin material, the content of the polycarbonate resin (A2a) Is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, still more preferably 15 to 45% by mass, based on 100% by mass of the total of (A1a), (A1b) and (A2a). %. If the content of the polycarbonate resin is less than 5% by mass, the laser light transmittance and the laser welding strength are likely to decrease, and if it exceeds 50% by mass, the moldability may decrease.

<Polyethylene terephthalate resin (A2b)>
(A) The polyethylene terephthalate resin (A2b) used for the thermoplastic polyester resin material is a resin having an oxyethylene oxyterephthaloyl unit composed of terephthalic acid and ethylene glycol as a main constituent unit for all constituent repeating units, and is oxy. It may contain a repeating unit having a configuration other than the ethylene oxyterephthaloyl unit. The polyethylene terephthalate resin is produced by using terephthalic acid or a lower alkyl ester thereof and ethylene glycol as a main raw material, but other acid components and / or other glycol components may be used together as a raw material.

Acid components other than terephthalic acid include phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-. Examples thereof include phenylenedioxydiacetic acid and structural isomers thereof, dicarboxylic acids such as malonic acid, succinic acid and adipic acid and derivatives thereof, and oxyacids such as p-hydroxybenzoic acid and glycolic acid or derivatives thereof.
Examples of the diol component other than ethylene glycol include aliphatic glycols such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, pentamethylene glycol, hexamethylene glycol, and neopentyl glycol, and cyclohexane. Examples thereof include alicyclic glycols such as dimethanol, aromatic dihydroxy compound derivatives such as bisphenol A and bisphenol S, and the like.

Further, the polyethylene terephthalate resin is a branched component, that is, an acid having a trifunctional ester-like performance such as tricarbaryl acid, trimellitic acid, trimellitic acid, or a tetrafunctional ester form such as pyromellitic acid, or glycerin, trimethylpropane, penta. A copolymer of 1.0 mol% or less, preferably 0.5 mol% or less, and more preferably 0.3 mol% or less of an alcohol having a trifunctional or tetrafunctional ester-forming ability such as erythrite. There may be.

The ultimate viscosity of the polyethylene terephthalate resin (A2b) is preferably 0.3 to 1.5 dl / g, more preferably 0.3 to 1.2 dl / g, and particularly preferably 0.4 to 0.8 dl / g. ..
The intrinsic viscosity of the polyethylene terephthalate resin is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

The concentration of the terminal carboxyl group of the polyethylene terephthalate resin (A2b) is preferably 3 to 60 eq / ton, particularly preferably 5 to 50 eq / ton, and more preferably 8 to 40 eq / ton. By setting the terminal carboxyl group concentration to 50 eq / ton or less, gas is less likely to be generated during melt molding of the resin material, and the mechanical properties of the obtained laser welding member tend to be improved. When the value is 3 eq / ton or more, the heat resistance, retention heat stability, and hue of the laser welding member tend to be improved, which is preferable.
The terminal carboxyl group concentration of the polyethylene terephthalate resin can be determined by dissolving 0.5 g of the polyethylene terephthalate resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / L benzyl alcohol solution of sodium hydroxide. The value.
As a method for adjusting the amount of the terminal carboxyl group, a conventionally known arbitrary method such as a method of adjusting the polymerization conditions such as a raw material charging ratio at the time of polymerization, a polymerization temperature, a depressurization method, a method of reacting a terminal blocking agent, etc. Just do it.

(A) When polybutylene terephthalate homopolymer (A1a) and / or polybutylene terephthalate copolymer (A1b) and polyethylene terephthalate resin (A2b) are contained as the thermoplastic polyester resin material, the polyethylene terephthalate resin (A2b) is contained. The amount is preferably 5 to 50% by mass, more preferably 10 to 45% by mass, still more preferably 15 to 50% by mass, based on 100% by mass of the total of (A1a), (A1b) and (A2b). It is 45% by mass. When the content of the polyethylene terephthalate homopolymer is less than 5% by mass, the laser light transmittance and the laser welding strength tend to decrease, and when it exceeds 50% by mass, the moldability tends to decrease.

[(A) Other resins that can be used for thermoplastic polyester resin materials]
Further, the (A) thermoplastic polyester resin material contains other thermoplastic resins other than the above-mentioned (A1a), (A1b), (A2a) and (A2b) within a range that does not impair the effects of the present invention. be able to. Specific examples of other thermoplastic resins include polyacetal resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfon resin, polyether sulfone resin, polyetherimide resin, polyether ketone resin, and polyolefin resin. Be done.

[(D) Plasticizer]
In the present invention, a plasticizer is further contained.
Examples of the plasticizer include various plasticizers, for example, ester-based plasticizers (aromatic polyvalent carboxylic acid ester, alicyclic polyvalent carboxylic acid ester, polyester, sucrose fatty acid ester, etc.), phosphoric acid ester-based plasticizer. Examples thereof include agents (tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, etc.), acrylic polymers, and the like. These plasticizers can be used alone or in combination of two or more. Among these plasticizers, a plasticizer having a high boiling point (for example, a plasticizer having a boiling point of 250 to 400 ° C., preferably 270 to 400 ° C., more preferably about 300 to 400 ° C.) is preferable.
In the present invention, it is presumed that by blending the (D) plasticizer, the melt viscosity on the permeation side and the absorption side is lowered by the heat at the time of welding, and the entanglement of both resins is increased, so that the welding strength is improved. ..

The aromatic polyvalent carboxylic acid ester may be an aromatic compound having a plurality of ester groups (alkoxycarbonyl group, cycloalkyloxycarbonyl group, aralkyloxycarbonyl group, etc.), and may be, for example, the formula φ- (COOR) n ( In the formula, φ represents a C6-12 allene ring such as a benzene or naphthalene ring, R represents an alkyl group, a cycloalkyl group or an aromatic group, n represents an integer of 2 or more, and R of each group COOR is the same. It may be present or different). These aromatic polyunsaturated carboxylic acid esters can be used alone or in combination of two or more.

Examples of the polyvalent carboxylic acid of the aromatic polyvalent carboxylic acid ester component include aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, their acid anhydrides, etc.) and aromatic tricarboxylic acids (tri). Examples thereof include merit acid (such as merit acid or its acid anhydride) and aromatic tetracarboxylic acid (pyromellitic acid or its acid anhydride).

In the aromatic polyunsaturated carboxylic acid ester-based plasticizer, the coefficient n is usually about 2 to 6, preferably about 2 to 4 (particularly 3 to 4). Polyunsaturated carboxylic acid esters having n of 3 or more are useful because they have high heat resistance.

Examples of the alkyl group constituting the alkyl ester include linear or branched C1- such as butyl, t-butyl, pentyl, hexyl, octyl, 2-ethylhexyl, isononyl group, decyl group, isodecyl group and triisodecyl group. 20 Alkyl groups and the like can be exemplified. Preferred alkyl groups are linear or branched C3-16 alkyl groups, especially linear or branched C4-14 alkyl groups. Examples of the cycloalkyl group constituting the cycloalkyl ester group include a C5-10 cycloalkyl group such as a cyclohexyl group, and examples of the aralkyl group constituting the aralkyl ester group include C6-12aryl-C1-4 such as a benzyl group. Alkyl groups can be exemplified.

Typical aromatic polyvalent carboxylic acid esters include trimellitic acid triC4-20 alkyl esters (tributyl trimellitic acid, trioctyl trimellitic acid, tritrimeritate (2-ethylhexyl), triisodecyl trimellitic acid, etc.), Trimeric acid tri-C5-10 cycloalkyl ester (tricyclohexyl trimellitic acid, etc.), triaralkyl trimellitic acid (tribenzyl trimellitic acid, etc.), dialkyl monoaralkyl trimellitic acid (di-ethylhexyl trimellitic acid) monobenzyl ), Tetra pyromellitic acid C4-20 alkyl ester (tetrabutyl pyromellitic acid, tetraoctyl pyromellitic acid, tetra2-ethylhexyl pyromellitic acid, tetraisodecyl pyromellitic acid, etc.), tetraaralkyl pyromellitic acid (tetraaramicyl pyromellitic acid) Benzyl, etc.), dialkyl dialalkyl pyromellitic acid (di-ethylhexyl pyromellitic acid, dibenzyl, etc.) and the like can be exemplified. The carboxylic acid ester may be a mixed ester having a different ester group (alkoxycarbonyl group, cycloalkyloxycarbonyl group, aralkyloxycarbonyl group, etc.).

The alicyclic polyvalent carboxylic acid ester-based plasticizer includes an alicyclic polyvalent carboxylic acid ester corresponding to the aromatic polyvalent carboxylic acid ester, for example, an alicyclic tricarboxylic acid (methylcyclohexentricarboxylic acid or its acid anhydride). Esters (linear or branched C1-20 alkyl esters (particularly linear or branched C4-14 alkyl esters), C5-10 cycloalkyl esters, aralkyl esters (particularly benzyl esters)), etc. Can be exemplified.

Polyol-based plasticizers include dicarboxylic acid components [aliphatic dicarboxylic acids (C6-12 alcandicarboxylic acids such as adipic acid and sebacic acid), aromatic dicarboxylic acids (asymmetric aromatic dicarboxylic acids such as phthalic acid and naphthalenedicarboxylic acid). ] And a glycol (including oligopolyester) produced by the reaction of a glycol component (C2-10 alkanediol such as butylene glycol, neopentyl glycol, hexamethylene glycol, etc.). These polyester-based plasticizers can be used alone or in combination of two or more. The weight average molecular weight of the polyester plasticizer is preferably 500 to 10000, more preferably 800 to 8000.

Examples of the phosphoric acid ester-based plasticizer include trialkyl phosphate (tributyl phosphate, tri-2-ethylhexyl phosphate and other phosphoric acid C4-14 alkyl esters) and triaryl phosphate (triphenyl phosphate, tricredyl phosphate). (Phosphate tri-C6-12 aryl ester, etc.) and the like can be exemplified.

The plasticizer of the acrylic polymer (hereinafter, may be simply referred to as the acrylic plastic agent) is at least a single or copolymer of the (meth) acrylic monomer, for example, the (meth) acrylic monomer. It may be a copolymer of and a copolymerizable monomer (a copolymer of a (meth) acrylic monomer and a styrene-based monomer). The plasticizer may be an oligomer (for example, an oligomer having a weight average molecular weight of about 500 to 8000 (preferably 800 to 5000)). The acrylic plasticizer may be referred to as a fluidity improver.

Examples of the (meth) acrylic monomer include (meth) acrylic acid, (meth) acrylic acid ester [for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and (meth). ) C1-18 alkyl ester of (meth) acrylic acid such as 2-ethylhexyl acrylate, hydroxylalkyl (meth) acrylate such as 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, ( Glycidyl acrylate and the like], (meth) acrylamide, (meth) acrylonitrile and the like. These (meth) acrylic monomers can be used alone or in combination of two or more.

Examples of the styrene-based monomer include styrene, vinyltoluene, α-methylstyrene, chlorostyrene, vinylnaphthalene and the like. These styrene-based monomers can be used alone or in combination of two or more. Among these styrene-based monomers, styrene, vinyltoluene, and α-methylstyrene are preferable, and styrene is particularly preferable.

The weight ratio of the (meth) acrylic monomer to the styrene-based monomer can be selected from, for example, the former / latter = 10/90 to 90/10, and is preferably 20/80 to 80/20. It may be about 30/70 to 70/30.

If necessary, the copolymerizable monomer may be copolymerized. Examples of the copolymerizable monomer include polymerizable polyvalent carboxylic acid (fumaric acid, maleic acid, etc.), vinyl ester-based monomer (for example, vinyl acetate, vinyl propionate, etc.) and the like. These copolymerizable monomers can be used alone or in combination of two or more.

The refractive index of the plasticizer is not particularly limited as long as the transparency of the laser light is not impaired, and is, for example, about 1.45 to 1.6, preferably about 1.48 to 1.58.

Among the above, in the present invention, as the (D) plasticizer, a non-volatile plasticizer, for example, an aromatic polyunsaturated carboxylic acid ester plasticizer and an acrylic plasticizer is used at the time of molding aging. It is preferable because bleeding is reduced.

In the present invention, the amount of the plasticizer (D) used is 0.01 to 5 parts by mass, preferably 0.05 to 4 parts by mass, based on 100 parts by mass of the (A) thermoplastic polyester resin material. More preferably, it is 0.1 to 3 parts by mass.
If the amount of the component (D) is too small, it is difficult to obtain the sufficient strength that is the object of the present invention. On the other hand, if the amount is too large, the fluidity is improved, burrs are likely to occur, and bleeding is likely to occur from the surface of the molded product under high temperature or high temperature and humidity.

[Other additives]
The laser welding resin composition of the present invention can also be blended with various additives, if desired. Examples of such additives include reinforced fillers, impact-resistant improvers, color aids, dispersants, stabilizers, UV absorbers, light stabilizers, antioxidants, antistatic agents, lubricants, and mold release agents. Examples thereof include agents, crystal accelerators, crystal nucleating agents, flame retardants, and epoxy compounds.

As the reinforcing filler that can be contained in the resin composition of the present invention, it has an effect of improving the mechanical properties of the resin composition obtained by blending with the resin, and a commonly used inorganic filler for plastics is used. be able to. Fibrous fillers such as glass fiber, carbon fiber, basalt fiber, wollastonite, and potassium titanate fiber can be preferably used. In addition, granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, and glass beads; plate-like fillers such as talc; scaly fillers such as glass flakes, mica, and graphite. Fillers can also be used. Above all, from the viewpoint of laser light transmission, mechanical strength, rigidity and heat resistance, it is preferable to use a fibrous filler, particularly glass fiber. As the glass fiber, either a round cross-sectional shape or an irregular cross-sectional shape can be used.
It is more preferable to use a reinforcing filler that has been surface-treated with a surface-treating agent such as a coupling agent. The glass fiber to which the surface treatment agent is attached is preferable because it is excellent in durability, moisture heat resistance, hydrolysis resistance, and heat shock resistance.

As the surface treatment agent, any conventionally known surface treatment agent can be used, and specific examples thereof include silane-based coupling agents such as aminosilane-based, epoxysilane-based, allylsilane-based, and vinylsilane-based coupling agents. Among these, an aminosilane-based surface treatment agent is preferable, and specifically, for example, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane and γ- (2-aminoethyl) aminopropyltrimethoxysilane are preferable. Take as an example.

Further, as other surface treatment agents, an epoxy resin-based surface treatment agent such as novolac type, a bisphenol A type epoxy resin-based surface treatment agent and the like are preferably mentioned, and treatment with a novolac type epoxy resin-based surface treatment agent is particularly preferable.
The silane-based surface treatment agent and the epoxy resin-based surface treatment agent may be used alone or in a plurality of types, and it is also preferable to use both in combination.

From the viewpoint of laser welding property and heat shock resistance, the glass fiber is preferably a glass fiber having an anisotropic cross-sectional shape in which the ratio of the major axis to the minor axis in the cross section is 1.5 to 10. The cross-sectional shape is preferably rectangular or oval in cross section, and the major axis / minor axis ratio is preferably in the range of 2.5 to 8, more preferably 3 to 6. When the major axis is D ₂ , the minor axis is D ₁ , and the average fiber length is L, the aspect ratio ((L × 2) / (D ₂ + D ₁ )) is preferably 10 or more. When such a flat glass fiber is used as described above, the warp of the molded product is suppressed, which is particularly effective in producing a box-shaped welded body.

The content of the reinforcing filler is preferably 5 to 150 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material. If the content of the reinforcing filler is less than 5 parts by mass, it is difficult to obtain sufficient strength and heat resistance, and if it exceeds 150 parts by mass, the fluidity and laser weldability tend to decrease. The content of the reinforcing filler is more preferably 15 to 130 parts by mass, still more preferably 20 to 120 parts by mass, and particularly preferably 30 to 100 parts by mass.

The impact modifier that can be contained in the resin composition of the present invention functions to improve the heat shock resistance of the resin composition. The impact resistance improving agent is not particularly limited as long as it has the effect of improving the impact resistance of the resin, but is limited to polyester elastomer, styrene elastomer, polyolefin elastomer, acrylic elastomer, polyamide elastomer, and polyurethane elastomer. , Fluorine-based elastomers, silicone-based elastomers, acrylic-based core / shell-type elastomers, and the like, but preferred examples include polyester-based elastomers and styrene-based elastomers.

The polyester-based elastomer is a thermoplastic polyester having rubber properties at room temperature, preferably a thermoplastic elastomer containing a polyester-based block copolymer as a main component, and has a high melting point and high crystalline aromatic polyester as a hard segment. , A block copolymer having an amorphous polyester or an amorphous polyether as a soft segment is preferable. The content of the soft segment of the polyester-based elastomer is at least 20 to 95 mol% in all the segments, and 50 to 50 to the block copolymer of polybutylene terephthalate and polytetramethylene glycol (PBT-PTMG copolymer). It is 95 mol%. The preferred soft segment content is 50-90 mol%, especially 60-85 mol%. Of these, polyester ether block copolymers, particularly PTMG-PBT copolymers, are preferable because they reduce the decrease in transmittance.

Specific examples of polyester-based elastomers include "Primaloy" (manufactured by Mitsubishi Chemical Corporation, trade name, registered trademark (same below)), "Perprene" (manufactured by Toyobo), "Hitrel" (manufactured by Toray DuPont), and " "Byron" (manufactured by Toyobo Co., Ltd.), "Polyester" (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like are preferably mentioned.

The styrene-based elastomer is composed of a styrene component and an elastomer component, and preferably contains the styrene component in an amount of usually 5 to 80% by mass, preferably 10 to 50% by mass, and particularly preferably 15 to 30% by mass. Examples of the elastomer component at this time include conjugated diene-based hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene, and more specifically, styrene-butadiene copolymer (SBS) elastomer and styrene. Examples thereof include a copolymer (SIS) elastomer with isoprene.
It is also preferable to use a resin (SEBS, SEPS) hydrogenated by hydrogenating the above-mentioned SBS elastomer or SIS elastomer.

Specific examples of styrene-based elastomers include "Dynaron" (manufactured by JSR, trade name, registered trademark (same below)), "Tough Tech" (manufactured by Asahi Kasei Chemicals), "Hybler", "Septon" (manufactured by Kuraray). And so on.

Further, as the impact resistance improving agent, a copolymerized elastomer containing an epoxy group is also preferable because it has good reactivity with a thermoplastic polyester resin such as polybutylene terephthalate and the decrease in laser transmittance is small.
The type of the copolymerized elastomer itself containing an epoxy group does not matter. For example, those in which an epoxy group is introduced into the above-mentioned styrene-based elastomer, polyolefin-based elastomer, acrylic-based elastomer and the like are preferably mentioned. For example, in the case of a styrene-butadiene copolymer in which polystyrene is copolymerized as a hard segment and butadiene is copolymerized as a soft segment, an epoxy group-containing elastomer can be obtained by epoxidizing the unsaturated double bond portion of the diene component.
Further, the olefin-based elastomer may have a polyolefin part in the soft phase, and ethylene propylene rubber such as EPR and EPDM can be preferably used.
The method for introducing the epoxy group is not particularly limited, and the epoxy group may be incorporated into the main chain, or the epoxy group-containing polymer may be introduced into the olefin elastomer in the form of a block or a graft. Preferably, a (co) polymer having an epoxy group is introduced in a grafted form.

Specific examples of copolymerized elastomers containing epoxy groups include "Bond First" (manufactured by Sumitomo Chemical Corporation, trade name, registered trademark (same below)), "Rotada" (manufactured by Arkema), and "Elvalois" (Mitsui). Examples include Dupont Polychemical (manufactured by Dupont Polychemical), "Paraloid" (manufactured by Rohm and Haas), "Metabren" (manufactured by Mitsubishi Chemical), and "Epofriend" (manufactured by Daicel Chemical Industries).

The impact resistance improving agent may be used alone or in combination of two or more. The content of the impact resistance improving agent is 0 to 20 parts by mass, preferably 1 to 18 parts by mass, more preferably 2 to 15 parts by mass, and further preferably 2 to 15 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material. It is 3 to 12 parts by mass, particularly preferably 3 to 7 parts by mass. If the content of the impact resistance improver exceeds 20 parts by mass, the heat resistance rigidity tends to decrease.

The epoxy compound that can be contained in the resin composition of the present invention functions to improve the laser welding property and the heat resistance to moisture and heat of the resin composition, and further improve the strength and durability of the weld portion of the molded product.
The epoxy compound may be any compound having one or more epoxy groups in one molecule, and is usually a glycidyl compound which is a reaction product of an alcohol, a phenol, a carboxylic acid or the like and epichlorohydrin, or an olefinic di-phenyl compound. A compound in which the heavy bond is epoxidized may be used.
Preferred specific examples of the epoxy compound include, for example, a bisphenol type epoxy compound such as a bisphenol A type epoxy compound and a bisphenol F type epoxy compound, a resorcin type epoxy compound, a novolac type epoxy compound, an alicyclic compound type diepoxy compound, and glycidyl ethers. Examples thereof include glycidyl esters and epoxidized polybutadiene.
Examples of the alicyclic epoxy compound include vinylcyclohexene dioxide and dicyclopentadiene oxide.

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

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

The epoxy compound is preferably an epoxy compound having an epoxy equivalent of 100 to 500 g / eq and a number average molecular weight of 2000 or less. If the epoxy equivalent is less than 100 g / eq, the amount of epoxy groups is too large, so that the viscosity of the resin composition becomes high, which tends to cause a decrease in the adhesion of the weld portion. On the contrary, when the epoxy equivalent exceeds 500 g / eq, the amount of the epoxy group is small, so that the effect of improving the moist heat resistance property of the resin composition tends not to be sufficiently exhibited. Further, when the number average molecular weight exceeds 2000, the compatibility with (A) the thermoplastic polyester resin material tends to decrease, and the mechanical strength of the molded product tends to decrease.
As the epoxy compound, a bisphenol A type epoxy compound or a novolac type epoxy compound obtained by reacting bisphenol A or novolak with epichlorohydrin is particularly preferable.

The content of the epoxy compound is 0 to 5 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material, but it is preferably 0.1 parts by mass or more in order to exhibit the effect. If the content is more than 3 parts by mass, cross-linking may proceed and the fluidity at the time of molding may deteriorate. Therefore, it is preferably contained in an amount of 0.2 to 3 parts by mass, particularly 0.2 to 2 parts by mass.

As the stabilizer that can be contained in the resin composition of the present invention, a phosphorus-based stabilizer, a sulfur-based stabilizer, and a phenol-based stabilizer are preferable.
Particularly preferably, it is a phenol-based stabilizer, and when the resin composition contains a polyethylene terephthalate resin or a polycarbonate resin, it is preferable to use a phenol-based stabilizer and a phosphorus-based stabilizer in combination.
Examples of the phosphorus-based stabilizer include phosphoric acid, phosphoric acid, phosphoric acid ester, phosphoric acid ester and the like, and among them, an organic phosphate compound, an organic phosphite compound or an organic phosphonite compound is preferable.

The organic phosphate compound is preferably given the following general formula:
(R ¹ O) _3-n P (= O) OH _n ... (1)
(In the formula (1), R ¹ is an alkyl group or an aryl group, which may be the same or different. N represents an integer of 0 to 2.). More preferably, ^{a long-chain alkyl acid phosphate compound having R 1} having 8 to 30 carbon atoms can be mentioned. Specific examples of the alkyl group having 8 to 30 carbon atoms include an octyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group and a hexadecyl group. Examples thereof include a group, an octadecyl group, an eikosyl group, a triacontyl group and the like.

Examples of long-chain alkyl acid phosphates include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, and cyclohexyl. Acid phosphate, phenoxyethyl acid phosphate, alkoxypolyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid Examples thereof include phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, bisnonylphenyl acid phosphate and the like. Of these, octadecyl acid phosphate is preferred.

The organic phosphite compound is preferably given the following general formula:
R ² OP (OR ³ ) (OR ⁴ ) ... (2)
(In the formula (2), R ² , R ³ and R ⁴ are hydrogen atoms, alkyl groups having 1 to 30 carbon atoms or aryl groups having 6 to 30 carbon atoms, respectively, and are of R ² , R ³ and R ^{4 respectively} . At least one of them is an aryl group having 6 to 30 carbon atoms).

Examples of the organic phosphite compound include triphenylphosphite, tris (nonylphenyl) phosphite, dilaurylhydrogenphosphite, triethylphosphite, tridecylphosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phenylphosphite, tristearyl phosphite, diphenylmonodecylphosphite, monophenyldidecylphosphite, diphenylmono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite , Hydrogenated bisphenol A phenol phosphite polymer, diphenylhydrogenphosphite, 4,4'-butylidene-bis (3-methyl-6-tert-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4 '-Isopropyridene diphenyl diphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4- tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, bis (2,4-di-tert-butylphenyl) pentaerythritoldi Phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) octylphosphite, bis ( 2,4-Dicumylphenyl) pentaerythritol diphosphite and the like. Among these, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite is preferable.

The organic phosphonite compound is preferably given the following general formula:
R ^5- P (OR ⁶ ) (OR ⁷ ) ・ ・ ・ (3)
In formula (6), R ⁵ , R ⁶ and R ⁷ are hydrogen atoms, alkyl groups having 1 to 30 carbon atoms or aryl groups having 6 to 30 carbon atoms, respectively, and are of R ⁵ , R ⁶ and R ⁷ . At least one of them is an aryl group having 6 to 30 carbon atoms).

Examples of the organic phosphonite compound include tetrakis (2,4-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite and tetrakis (2,4-di-n-butylphenyl) -4,4'-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylenediphospho Nite, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrax (2,6-di-n-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-n-butylphenyl) 2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite and the like. ..

As the sulfur-based stabilizer, any conventionally known sulfur atom-containing compound can be used, and among them, thioethers are preferable. Specifically, for example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine). ), 2-Mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickeldibutyldithiocarbamate, nickelisopropylxanthate, trilauryltrithiophosphite. Of these, pentaerythritol tetrakis (3-dodecylthiopropionate) is preferred.

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

As the stabilizer, one type may be contained, or two or more types may be contained in any combination and ratio.

The content of the stabilizer is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material. If the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur, and 2 parts by mass is used. If it exceeds the amount, the amount becomes excessive, and there is a tendency that silver is generated and hue deterioration is more likely to occur. The content of the stabilizer is more preferably 0.001 to 1.8 parts by mass, still more preferably 0.1 to 1.5 parts by mass.

As the release agent that can be contained in the resin composition of the present invention, known release agents usually used for polyester resins can be used, and among them, polyolefin-based compounds, fatty acid ester-based compounds, and silicone-based compounds are used. One or more mold release agents selected are preferred.

Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax, and among them, those having a mass average molecular weight measured by GPC of 700 to 10000, more preferably 900 to 8000 are preferable. Further, a modified polyolefin compound in which a hydroxyl group, a carboxyl group, a hydroxyl group, an epoxy group or the like is introduced into the side chain is also particularly preferable.

Examples of the fatty acid ester-based compound include fatty acid esters such as glycerin fatty acid esters, sorbitan fatty acid esters, and pentaerythritol fatty acid esters, and partial saponified products thereof. Among them, the number of carbon atoms is 11 to 28, preferably 17 carbon atoms. A fatty acid ester composed of ~ 21 fatty acids is preferable. Specific examples thereof include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monostearate, pentaerythritol distearate, and pentaerythritol tetrastearate.

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

The content of the release agent is preferably 0.05 to 2 parts by mass with respect to 100 parts by mass of the (A) thermoplastic polyester resin material. If it is less than 0.05 parts by mass, the surface property tends to be deteriorated due to poor mold release during melt molding, while if it exceeds 2 parts by mass, the kneading workability of the resin composition is lowered and the kneading workability is lowered. Cloudiness may be seen on the surface of the molded product. The content of the release agent is preferably 0.07 to 1.5 parts by mass, more preferably 0.1 to 1.0 parts by mass.

The method for producing the resin composition of the present invention can be carried out according to a conventional method for preparing a resin composition. Usually, each component and various additives added as desired are mixed well together and then melt-kneaded in a uniaxial or twin-screw extruder. Further, the resin composition of the present invention can also be prepared by premixing each component without premixing or only a part thereof, supplying the component to an extruder using a feeder and melt-kneading. Further, (A) a masterbatch prepared by melting and kneading a part of the resin constituting the thermoplastic polyester resin material with a part of another resin, and then the remaining polyester resin and the like. Ingredients may be blended and melt-kneaded.
When a fibrous reinforcing filler such as glass fiber is used, it is also preferable to supply it from a side feeder in the middle of the cylinder of the extruder.

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

[Laser welding molded body]
The method for producing the molded product is not particularly limited, and any molding method generally used for the polyester resin composition can be adopted. For example, an injection molding method, an ultra-high speed injection molding method, an injection compression molding method, a two-color molding method, a hollow molding method such as gas assist, a molding method using a heat insulating mold, and a rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermal molding method, rotary molding method, laminated molding method, press molding method, Blow molding method and the like can be mentioned, and injection molding is particularly preferable.

In the laser welding resin composition of the present invention, the absorbance a (absorbance converted to a thickness of 1 mm) of the molded product before laser welding is preferably 0.05 to 1.0, and 0.08 to 0. It is more preferably 9. By adjusting this value, the spread of resin melting (size of melting pool) in laser welding can be adjusted. Therefore, even in butt welding, a high welding strength sufficiently sufficient for practical use can be obtained. Further, even at the time of superposition welding or butt welding, the range of laser welding processability is widened because the gap welding property is excellent.
The absorbance a can be adjusted by blending additives such as an alloy type of the base resin, an elastomer, and a reinforcing material, and further by adjusting the amount of niglosin. Further, when the molded product is manufactured, it can be adjusted by adjusting the molding conditions such as the surface degree of the mold, the distance from the gate, the injection rate, the surface progress coefficient, and the mold temperature.
For the absorbance a, use an ultraviolet-visible near-infrared spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation) to determine the transmittance T (%) and reflectance R (%) of a 1 mm thick molded product at a wavelength of 940 nm. It is calculated and calculated by the following formula using the value, but when measuring using a molded plate whose thickness is not 1 mm, the wall thickness t (mm) of the measuring part is used and the thickness is 1 mm as a / t. The value converted to.
Absorbance a = -log {T / (100-R)}

In the laser welding resin composition of the present invention, the incident rate K (incident rate converted to a thickness of 1 mm) of the molded product before laser welding is preferably in the range of 20 to 80%, more preferably 25 to 75. %, Especially preferably in the range of 30 to 70%.
When the incident rate is less than 20%, the butt welding performance is lowered and the gap welding performance is also lowered. On the contrary, when the incident rate exceeds 80%, the welding performance is lowered due to the superposition, and the gap welding performance is also lowered.
Since the amount of transmitted laser light and the amount of absorbed laser light are adjusted by setting the incident rate K in such a range, a molded body made of a laser light transmitting resin and a laser are used as in conventional laser welding. It is not necessary to use two types of molded bodies made of a light-absorbing resin, and it is possible to provide a polyester-based laser welding molded body capable of laser welding with only one type of resin material. In particular, the effect of the present invention is remarkable when welded bodies made of the same type of resin material are welded to each other.

As a method for adjusting the incident rate, it is preferable to use a resin composition having a crystallization temperature (Tc) of 190 ° C. or lower. That is, by controlling the crystallization temperature (Tc) to be low, the incident rate can be adjusted to a preferable range.
The incident rate also changes greatly depending on the transmittance of the laser light. Molding conditions can be mentioned as factors that change the transmittance, and the molding conditions include injection rate, mold temperature, resin temperature, holding pressure, and the like. Above all, it is easy to change depending on the injection rate and the mold temperature. Further, in the mold structure, it is likely to change depending on the mold surface, the gate shape, the position of the gate, and the number of gates. Further, in the molded product, it greatly changes depending on the portion where the transmittance is measured and the distance from the gate position at the time of molding. Therefore, the incident rate can be adjusted to a preferable range by appropriately determining these conditions.

The crystallization temperature (Tc) is preferably 188 ° C. or lower, more preferably 185 ° C. or lower, still more preferably 182 ° C. or lower, and particularly preferably 180 ° C. or lower. The lower limit thereof is usually 160 ° C., preferably 165 ° C. or higher. The crystallization temperature (Tc) is measured by DSC. The details are as described in the examples.

The laser welding resin composition of the present invention is molded into a laser welding member having a desired shape by an injection molding method. As the injection molding method, for example, a high-speed injection molding method, an injection compression molding method, or the like can be used.
The conditions for injection molding are not particularly limited, but the injection speed is preferably 10 to 500 mm / sec, more preferably 30 to 400 mm / sec, further preferably 50 to 300 mm / sec, and particularly preferably 80 to 200 mm / sec. preferable.
The higher the injection speed, the higher the transmittance, which affects the incident rate. However, if the injection speed is too high, gas burning will occur at the flow end of the molded product, so it is preferable to take measures such as lowering the injection speed to an appropriate level or increasing the size of the gas vent in the mold structure.

The resin temperature is preferably 250 to 280 ° C, more preferably 255 to 275 ° C. The mold temperature is preferably 40 to 130 ° C, more preferably 50 to 100 ° C.
The lower the mold temperature, the higher the transmittance, which in turn affects the incident rate. If the mold temperature is too low, the crystallinity of the molded product will be low, resulting in large post-shrinkage and poor dimensional stability. It is also preferable to adjust the mold temperature.

Moreover, the injection rate, which is defined as a resin material capacity per unit is injection time from the discharge nozzle to the mold cavity of the injection molding machine is preferably ^{10~300cm 3 / sec, 15~200cm 3 /} sec is More preferably, 25 to 100 cm ³ / sec is further preferable, and 50 to 90 cm ³ / sec is particularly preferable. By setting the injection rate to such a range, it is possible to adjust the incident rate of the welded portion such as the anti-gate side portion of the injection-molded member to a preferable range, and by adjusting the gate position, welding in the member. It is possible to adjust the incident rate of the part to a more appropriate range. In injection molding, the volume of the resin material injected in one injection is controlled by adjusting the injection volume of the resin material per unit time and the time required for injection, but the material capacity of the resin material per unit time is injected. The rate (unit: cm ³ / sec).

Further, it is preferable to perform injection molding under the condition that the surface advance coefficient defined below is 100 to 1200 ^{cm 3 / sec · cm.} By setting the surface advancing coefficient to such a range, the incident rate of the anti-gate side portion of the member can be adjusted to a preferable range, and by adjusting the gate position, the incident rate of the welded portion in the member can be adjusted to a more appropriate range. Adjustment is possible.
Surface advancing coefficient: A value obtained by dividing the injection rate by the average thickness of the mold cavity into which the resin material is injected. A preferable range of the surface advancing coefficient is 200 to 1100 ^{cm 3} / sec · cm, more preferably 250 to 1000 cm ^3. It is / sec · cm, more preferably 300 to 950 cm ^{3 / sec · cm, and particularly preferably 330 to 930 cm 3} / sec · cm.

The shape of the laser welded molded product is arbitrary, and it may be a deformed extruded product (rod, pipe, etc.) that is subjected to welding by butting the ends, and is an energized component that requires particularly high waterproofness and airtightness. Molded products with metal inserts used for electronic parts and the like are also preferable.

[Laser welded body]
When the molded product made of the laser-welded resin composition of the present invention is used, it is not necessary to use two types of the molded product made of the laser light-transmitting resin and the laser light-absorbing resin, which have been conventionally required. .. In addition, since the transmission depth of the laser beam is large, a large melting depth can be secured, so that not only superposition welding but also butt welding between the ends of the laser welding molded body, which has not been possible until now, is sufficient. High welding strength can be achieved. Further, even if a gap is temporarily formed in the joining portion due to sink marks or warpage during molding, the gap is 0.1 mm or more, preferably 0.2 mm or more, further 0.5 mm or more, particularly 0. Laser welding is possible even when the thickness is 0.8 mm or more.
The type of laser light to be irradiated is arbitrary as long as it is near infrared laser light, and YAG (yttrium aluminum garnet crystal) laser (wavelength 1064 nm), LD (laser diode) laser (wavelength 808 nm, 820 nm, 840 nm, 880 nm). , 940 nm) and the like can be preferably used.

The shape, size, thickness, etc. of the laser-welded welded body are arbitrary, and the welded body can be used for transportation equipment parts such as automobiles, electrical and electronic equipment parts, industrial machine parts, and other consumer parts. Suitable.

As a method of laser welding, butt welding, superposition welding and the like can be preferably mentioned.
In the butt welding, as shown in FIG. 2, two molded bodies 1 and 2 are butted against each other, and while scanning, laser light 4 is irradiated to generate a welded portion 5, whereby a laser welded body is formed.

In the superposition welding, as shown in FIG. 3, two molded bodies 1 and 2 are superposed and scanned while being irradiated with laser light 4 to generate a welded portion 5, whereby a laser welded body is formed. ..

By butting or superimposing the molded products obtained from the colored resin composition of the present invention and laser welding, the obtained laser welded body has considerably improved welding strength, which is required for the laser welded body. Meet the practical strength to be. Further, considering the laser welding conditions, it can be seen that the permissible range of the amount of energy generated by the laser beam has a remarkably wide range, and a molded product capable of dealing with such a wide range of laser welding conditions has a complicated structure. It is possible to provide highly practical laser welding for molded body welding of the above, molded body welding with varying thickness, and the like. In addition, it is a laser welded body that has heat-resistant discoloration and suppresses bleeding of colorants, and has little effect on electronic components.

Next, the present invention will be described in more detail with reference to examples, but of course, the present invention is not limited to these.

Production Examples 1 to 3 of the colorant are shown below, and Table 1 shows the composition ratio and the like.

(Colorant Production Example 1: Production of Colorant Example 1)
Anthraquinone dye C1 (maximum absorption wavelength 628 nm CI solvent blue 104) 0.66 parts by mass, perinone dye C2 (maximum absorption wavelength 472 nm CI solvent red 179) 0.58 parts by mass and anthraquinone dye C3 (maximum absorption) Wavelength 446 nm CI Solvent Yellow 163) 0.56 parts by mass was placed in a compounding machine and stirred for 5 hours to obtain 1.8 parts by mass of Colorant Example 1.

The absorbance and maximum absorption wavelength of the dye used above were measured by the following methods, and the absorption curve is shown in FIG.
[Measurement method of dye absorbance and maximum absorption wavelength]
Weigh 0.05 g of the dye sample, dissolve it in dimethylformamide (DMF), and make adjustments in a 100 ml volumetric flask. Next, 2 ml of the adjusting solution was measured with a whole pipette, and the prepared solution was prepared by measuring up with a 50 ml volumetric flask using DMF.
The absorption spectrum of the obtained adjusting solution was measured using an ultraviolet-visible spectrophotometer (trade name: UV-1100 manufactured by Shimadzu Corporation).

(Colorant Production Examples 2-3: Production of Colorant Example 2 and Comparative Colorant Example 1)
In Production Examples 2 and 3, Colorant Example 2 and Comparative Colorant Example 1 were obtained in the same manner as in Production Example 1 except that the compounding composition of Production Example 1 was changed to the composition shown in Table 1.

(Manufacturing of molded product and laser welding using the molded product)
Using any of the colorant examples produced above, a molded product made of a resin composition was produced by the method described below. Then, laser welding was performed using the molded body.
The raw materials used other than the colorant are the components shown in Table 2 below.

(Examples 1 to 11, Comparative Examples 1 to 5)
[Manufacturing of laser welded body by butt welding]
Each component and niglocin (NUBIAN BLACK TH-807) shown in Tables 1 and 2 are blended in an amount shown in Table 3 (both by mass), and this is blended in a 30 mm bent type twin-screw extruder (Japan Steel Works). It is put into the main hopper of "TEX30α" manufactured by Japan Steel Works, and the glass fiber is supplied from the 7th side feeder from the hopper, the extruder barrel set temperature C1 to C15 is 260 ° C, the die is 250 ° C, and the screw rotation speed is 200 rpm. , Kneaded under the condition of a discharge rate of 40 kg / hour and extruded into a strand shape to obtain pellets of a resin composition.

The crystallization temperature (Tc) of the resin composition was raised to 30 to 300 ° C. at a heating rate of 20 ° C./min using a differential scanning calorimetry (DSC) machine (“Pyris Diamond” manufactured by PerkinElmer). After holding at 300 ° C. for 3 minutes, the temperature was measured as the peak top temperature (unit: ° C.) of the exothermic peak observed when the temperature was lowered at a temperature lowering rate of 20 ° C./min.
It is considered that the lower the crystallization temperature (Tc), the slower the solidification, and therefore the higher the laser welding strength and the weld strength.

After drying the resin composition pellets obtained above at 120 ° C. for 5 hours, an injection molding machine (NEX80-9E, manufactured by Nissei Resin Industry Co., Ltd.) was used at a cylinder temperature of 255 ° C. and a mold temperature of 65 ° C. A 0 mm thick and 2.0 mm thick ASTM No. 4 dumbbell piece was manufactured under the conditions of an ^{injection speed of 100 mm / sec, an injection rate of 66 cm 3} / sec, and a surface advance coefficient of 880 ^{cm 3 / sec · cm.}

[Optical characteristics: Measurement of transmittance, reflectance and absorbance]
At the welding part on the anti-gate side of the 1 mm thick ASTM No. 4 dumbbell, a transmittance T (%) at a wavelength of 940 nm was used using an ultraviolet visible near infrared spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation). The reflectance R (%) was determined. Further, the absorbance a was determined using the obtained reflectance value.
[How to find the incident rate]
The incident rate K (unit:%) was calculated by the following formula.
Incident rate K (%) = 100-transmittance-reflectance The incident rate K is the incident rate of the molded product at a thickness of 1 mm with respect to a laser beam having a wavelength of 940 nm. In the case of the molded product of ASTM4 dumbbell (1 mm), it was derived from the measurement results of the transmittance and the reflectance of the part on the opposite side of the gate (the part on the opposite side of the gate in which the resin was injected).

Laser welding (dumbbell piece butt welding, gap welding strength):
Using two 2 mm thick ASTM4 dumbbells 11 and 12 having the same composition obtained above, a laser welding device manufactured by Fine Devices (laser wavelength: 940 nm, laser spot diameter: Φ2.1 mm, laser head and test piece). Using a distance between them (79.7 mm), as shown in FIG. 4, the ends of the dumbbell 11 and the dumbbell 12 on the opposite side (anti-gate side) of the resin injection gate are abutted against each other, and the abutting portion 13 is made of metal. The ones sandwiching the single spacers 15 and 15'are placed on a glass base (not shown), the glass plate 16 is placed on the dumbbells 11 and 12, and the pressure of 0.4 MPa is applied from the side. Welding was performed by irradiating the laser beam 17 under the conditions of a laser output of 200 W, a laser scanning speed of 20 mm / sec, and a laser scanning distance of 16 mm. At that time, the gap spacing created by the metal spacers 15 and 15'was changed to 0.0 mm to 0.8 mm shown in Table 3, and the span spacing was 160 mm using an Instron 5544 universal tester. Under the condition of a tensile speed of 5 mm / min, a load (unit: N) for breaking by applying a load in the pulling direction of arrow a in FIG. 4 was determined.
It should be noted that the weldability is excellent not only in high welding strength but also in maintaining high welding strength under any conditions, which means that the range of laser welding conditions is wide. Is evaluated as.

Weld strength:
UL94 (Subject 94 of Underwriters Laboratories) combustion test piece with a thickness of 1.6 mm is injected with resin at two-point gates from both sides of the test piece in the same manner as in the case of molding the ASTM4 dumbbell described above. Then, a UL94 combustion test piece having a thickness of 1.6 mm having a weld line formed in the center of the test piece was injection-molded, and the weld bending strength (unit) was obtained under the conditions of a span interval of 40 mm and a test speed of 2 mm / min. : MPa) was measured.
The results are listed in Table 3 below.

The laser welding resin composition of the present invention has extremely excellent laser welding processability in addition to high coloring property. Therefore, the resin composition of the present invention can be suitably and widely applied to automobile parts, electrical and electronic equipment parts, and other materials, and thus has very high industrial applicability.

Claims (13)

A resin composition used for welding by laser light.
(A) With respect to 100 parts by mass of a thermoplastic polyester resin material containing a polybutylene terephthalate homopolymer and / or a polybutylene terephthalate copolymer.
(B) Niglosin 0.0005 to 0.5 parts by mass,
(C) 0.01 to 2 parts by mass of colorant containing anthraquinone dye, and
(D) A laser welding resin composition containing 0.01 to 5 parts by mass of a plasticizer. (C) The colorant is a perinone dye C2 having a maximum absorption wavelength in the range of 460 to 480 nm and an anthraquinone dye C1 having a maximum absorption wavelength in the range of 590 to 635 nm, and the mass ratio C2 / C1 of the two is 0.4 to. The laser welding resin composition according to claim 1, which is a colorant contained in a ratio of 2. (A) The thermoplastic polyester resin material contains a polybutylene terephthalate homopolymer and a polybutylene terephthalate copolymer, and the content of the polybutylene terephthalate copolymer is 5 to 95% by mass with respect to a total of 100% by mass of both. The laser-welded resin composition according to claim 1 or 2. (A) The claim that the thermoplastic polyester resin material contains a polybutylene terephthalate homopolymer and a polyethylene terephthalate resin, and the content of the polyethylene terephthalate resin is 5 to 50% by mass with respect to a total of 100% by mass of both. The laser-welded resin composition according to any one of 1 to 3. (A) The thermoplastic polyester resin material contains polybutylene terephthalate homopolymer and polycarbonate resin, and the content of the polycarbonate resin is 5 to 50 mass with respect to 100% by mass of the total of polybutylene terephthalate homopolymer and polycarbonate resin. %. The laser-welded resin composition according to claim 1 or 2. The laser welding resin composition according to any one of claims 1 to 5, wherein the plasticizer is at least one selected from an aromatic polyunsaturated carboxylic acid ester and an acrylic polymer. The laser welding according to any one of claims 1 to 6, wherein the absorbance a (absorbance converted to a 1 mm thick molded plate) of the molded plate made of the resin composition with respect to 940 nm laser light is 0.05 to 1. Resin composition for. Wherein (incidence rate in terms of the molding plate having a thickness of 1mm) incidence rate K with respect to the laser beam forming plate made of a resin composition, a laser according to any one of 20-80% der Ru請Motomeko 1-7 Welding resin composition.
However, the incident rate K (%) = 100-transmittance-reflectance. A laser welding molded article comprising the laser welding resin composition according to any one of claims 1 to 8. The laser welded body of the molded product according to claim 9. The laser welded body according to claim 10, wherein the welded body has a gap of 0.1 mm or more when the welded body is welded, at least in a part of the welded portion. The laser welded body according to claim 10 or 11, wherein the molded bodies are butt welded to each other. The laser welded body according to claim 10 or 11, wherein the molded bodies are superposed and welded together.

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