JP2022028718A - Member for laser welding and molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a laser welded molding which performs laser welding using a member for laser welding having a welding part having high laser transmittance and excellent laser welding workability.

SOLUTION: There is provided a method for manufacturing a laser welded molding in which a thermoplastic polyester-based resin material for a first laser welding member contains specific amounts of a polybutylene terephthalate resin, a polycarbonate resin and organic phosphoric acid phosphate, a resin material of a second member is a thermoplastic polyester-based resin composition and contains carbon black or a laser beam absorbing dye, a laser welded part in the first member is separated from a gate of an injection molding die by 15 mm or more, has light transmittance in a laser beam at a wavelength of 940 nm of 40% or more, and has a crystallization temperature of 188°C or lower.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a laser welding member and a molded product, and more particularly to a laser welding member having a high laser transmittance and excellent laser welding processability and a molded product laser-welded using the same.

In recent years, in automobile parts and consumer parts, from the environmental aspect such as weight reduction and recycling, resinization of parts that conventionally used metal and miniaturization of resin products are progressing. 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. ing. In particular, thermoplastic polyester resins such as polybutylene terephthalate resin have excellent mechanical strength and moldability, and are flame-retardant, so they are widely used for electrical and electronic parts that require fire safety. There is.
Recently, in order to manufacture these equipment parts, the number of cases where parts are bonded to each other by welding to improve productivity efficiency is increasing, and among them, laser welding, which has less influence on electronic parts, has been widely used. There is.

However, compared to polycarbonate resins and polystyrene-based resins, thermoplastic polyester resins, especially polybutylene terephthalate resins, have poor laser welding processability and tend to have insufficient welding strength, so laser welding resin materials. If anything, it is not suitable.

In order to improve the laser weldability of the polybutylene terephthalate resin, a method using a copolymerized polybutylene terephthalate (Patent Document 1) has been proposed. However, with this method, sufficient welding properties may not be obtained due to gaps between the welding members caused by warpage deformation of the molded product and the like. Further, a method of adding a laser transmission absorber such as niglocin to a thermoplastic resin to improve the weldability (Patent Document 2) has also been proposed.
In particular, the flame-retardant polybutylene terephthalate resin has low laser permeability, and laser welding is often difficult. Patent Document 3 proposes a method of achieving both laser permeability and flame retardancy by adding phosphinic acids to a polybutylene terephthalate resin, but the laser permeability is low and the effect of warpage of a molded product is present. In many cases, sufficient welding strength could not be obtained.

Japanese Patent No. 3510817 Japanese Unexamined Patent Publication No. 2008-1112 International release WO2007-77794

As described above, attempts to improve the laser welding processability by blending other components with a thermoplastic polyester resin such as polybutylene terephthalate resin are likely to be accompanied by various problems. The welding member for laser welding is often manufactured by injection molding, and is molded by injecting a resin in a flowing state from a gate provided in the cavity of the molding die. In particular, in recent years, the weight and thickness of parts have been rapidly reduced, and their characteristics and performance are likely to vary depending on the part of the molded product.

An object (problem) of the present invention is to provide a laser welding member having a high laser transmittance and excellent laser welding processability in view of the above situation.

As a result of repeated studies on individual parts of a welding member obtained by injection molding a thermoplastic polyester resin, the present inventor has made a specific part of the molded product a welding part for laser welding, which is an excellent laser. We have found that it can exhibit transparency and laser welding processability, and have reached the present invention.
The present invention relates to the following laser welding members, molded products and laser welding methods.

[1] A laser welding member made by injection molding a thermoplastic polyester resin material.
The laser-welded portion of the member is located at a position separated from the gate of the injection molding die by 15 mm or more, and the light transmittance of the laser light having a wavelength of 940 nm is 30% or more. Material.
[2] The laser welding member according to the above [1], which is formed by injection molding a thermoplastic polyester resin material under the condition of an injection rate of 10 to 300 cm ³ / sec as defined below.
Injection rate: Resin material capacity per unit time ejected from the ejection nozzle of the injection molding machine into the mold cavity [3] Thermoplastic polyester under the condition of a surface traveling coefficient of 100 to 1200 cm ³ / sec · cm defined below. The laser welding member according to the above [1] or [2], which is formed by injection molding a based resin material.
Surface progress coefficient: The value obtained by dividing the injection rate by the thickness of the mold cavity into which the resin material is injected. [4] The melt volume rate of the thermoplastic polyester resin material (measured at 250 ° C. and a load of 5 kg). The laser welding member according to any one of the above [1] to [3], which is 10 cm ^3/10 minutes or more.

[5] The laser welding member according to any one of the above [1] to [4], wherein the thermoplastic polyester resin material contains a polybutylene terephthalate resin and / or a polyethylene terephthalate resin.
[6] The thermoplastic polyester resin material contains a polybutylene terephthalate resin and a polyethylene terephthalate resin, and the content of the polyethylene terephthalate resin is 5 to 50% by mass based on 100% by mass of the total of the polybutylene terephthalate resin and the polyethylene terephthalate resin. %. The laser welding member according to any one of the above [1] to [5].
[7] The thermoplastic polyester resin material contains a polybutylene terephthalate homopolymer and a modified polybutylene terephthalate resin, and the content of the modified polybutylene terephthalate resin is 100% by mass in total of the polybutylene terephthalate resin and the modified polybutylene terephthalate resin. The laser welding member according to any one of the above [1] to [6], which is 10 to 70% by mass with respect to the above.
[8] The thermoplastic polyester-based resin material contains a polybutylene terephthalate resin and a polycarbonate resin, and the content of the polycarbonate resin is 10 to 50% by mass with respect to a total of 100% by mass of the polybutylene terephthalate resin and the polycarbonate resin. The laser welding member according to any one of the above [1] to [4].
[9] The thermoplastic polyester resin material contains a polybutylene terephthalate resin, polystyrene and / or a butadiene rubber-containing polystyrene and a polycarbonate resin, and a total of 100 polybutylene terephthalate resin, polystyrene and / or a butadiene rubber-containing polystyrene and a polycarbonate resin. The above [1] to [4] containing 30 to 90% by mass of polybutylene terephthalate resin, 1 to 50% by mass of polystyrene and / or polystyrene containing butadiene rubber, and 1 to 50% by mass of polycarbonate resin on a mass% basis. The laser welding member described in any one.

[10] The laser welding member according to any one of the above [1] to [9], which is used for the member on the laser transmission side.
[11] The first laser welding member according to any one of the above [1] to [10] and the second member made of a resin material having laser absorption are attached to the first laser welding member side. A molded product that is laser-welded by irradiating it with laser light.
[12] A first laser welding member made by injection molding a thermoplastic polyester resin material and a second member made of a resin material having laser absorption are laser-coated from the first laser welding member side. It is a method of manufacturing a laser welded molded product that is irradiated with light and laser welded.
The laser-welded portion of the first member is characterized in that the distance from the gate of the injection molding mold is 15 mm or more, and the light transmittance of the laser light having a wavelength of 940 nm is 30% or more. A method for manufacturing a laser welded molded product.

The laser welded member formed by injection molding the thermoplastic polyester resin material of the present invention has a high laser transmission rate at the welded portion and is excellent in laser welding processability. , Excellent welding strength.

It is a top view which shows the position on the injection-molded article of the transmission material 1 to 3 used in an Example. It is a schematic diagram which shows the laser welding intensity measuring method in an Example. (A) shows a view of the laser absorber and the transmissive material from the side, and (b) shows a view from above. 6 is a photograph of a backscattered electron image obtained by SEM / EDS analysis of the surface layer portion of the molded product obtained in Example 20. It is a perspective view of the box-shaped molded body used for the evaluation of the warpage property in an Example.

The laser welding member of the present invention is a laser welding member formed by injection molding a thermoplastic polyester resin material.
The laser-welded portion of the member is characterized in that the distance from the gate of the injection molding die is 15 mm or more, and the light transmittance in the laser light having a wavelength of 940 nm is 30% or more.

Hereinafter, the contents of the present invention will be described in detail. The following description may be based on representative embodiments and examples of the present invention, but the present invention is not construed as being limited to such embodiments and examples.

[Thermoplastic polyester resin material]
The resin material used for the laser welding member of the present invention contains a thermoplastic polyester resin as a main component.
The thermoplastic polyester resin is a polyester obtained by polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound, polycondensation of these compounds, or the like, and may be either homopolyester or copolyester. ..

As the dicarboxylic acid compound constituting the thermoplastic polyester resin, an aromatic dicarboxylic acid or an ester-forming derivative thereof is preferably used.
Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, and the like. Biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulphon-4,4'-dicarboxylic acid , Diphenylisopropyridene-4,4'-dicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p -Terphenylene-4,4'-dicarboxylic acid, pyridine-2,5-dicarboxylic acid and the like can be mentioned, and terephthalic acid can be preferably used.

Two or more kinds of these aromatic dicarboxylic acids may be mixed and used. As is well known, dimethyl ester or the like can be used as an ester-forming derivative in the polycondensation reaction in addition to the free acid.
In addition, if it is a small amount, along with these aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecandioic acid and sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1 , 4-Cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids can be mixed and used.

Examples of the dihydroxy compound constituting the thermoplastic polyester resin include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol and triethylene glycol. , Cyclohexane-1,4-dimethanol and other alicyclic diols, and mixtures thereof. If the amount is small, one or more long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, or the like may be copolymerized.
In addition, aromatic diols such as hydroquinone, resorcin, naphthalene diol, dihydroxydiphenyl ether, and 2,2-bis (4-hydroxyphenyl) propane can also be used.

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

As the thermoplastic polyester resin, a resin mainly composed of a polycondensation of a dicarboxylic acid and a diol, that is, a resin in which 50% by mass, preferably 70% by mass or more of the total resin is composed of this polycondensate is used. The dicarboxylic acid is preferably an aromatic carboxylic acid, and the diol is preferably an aliphatic diol.

Of these, polyalkylene terephthalate in which 95 mol% or more of the acid component is terephthalic acid and 95% by mass or more of the alcohol component is an aliphatic diol is preferable. Typical examples are polybutylene terephthalate and polyethylene terephthalate. It is preferable that these are close to homopolyester, that is, 95% by mass or more of the whole resin is composed of a terephthalic acid component and a 1,4-butanediol or ethylene glycol component.

The intrinsic viscosity of the thermoplastic polyester resin is preferably 0.3 to 2 dl / g. From the viewpoint of formability and mechanical properties, those having an intrinsic viscosity in the range of 0.5 to 1.5 dl / g are more preferable. If the intrinsic viscosity is lower than 0.3 dl / g, 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 deteriorated.
The intrinsic viscosity of the thermoplastic polyester resin 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 thermoplastic polyester resin may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. .. 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 the terminal carboxyl group is not particularly determined, but is usually 10 eq / ton.

The amount of terminal carboxyl groups in the thermoplastic polyester resin is a value measured by dissolving 0.5 g of the polyester resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. As a method for adjusting the amount of the terminal carboxyl group, a method for adjusting the polymerization conditions such as the raw material charging ratio at the time of polymerization, the polymerization temperature, the depressurization method, the method for reacting the terminal blocking agent, and the like, any conventionally known method can be used. Just do it.

Among them, the thermoplastic polyester resin preferably contains a polybutylene terephthalate resin and / or a polyethylene terephthalate resin, and 50% by mass or more of the thermoplastic polyester resin is preferably polybutylene terephthalate resin.

Polybutylene terephthalate resin is produced by melt-polymerizing a dicarboxylic acid component containing terephthalic acid as a main component or an ester derivative thereof and a diol component containing 1,4-butanediol as a main component by a batch method or a sequential method. can do. Further, the degree of polymerization (or molecular weight) can be increased to a desired value by producing a low molecular weight polybutylene terecturate resin by melt polymerization and then performing solid phase polymerization under a nitrogen stream or under reduced pressure.

The polybutylene terephthalate resin is preferably manufactured by a continuous melt polycondensation method of a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing 1,4-butanediol as a main component.

The catalyst used in carrying out the esterification reaction may be a conventionally known one, and examples thereof include titanium compounds, tin compounds, magnesium compounds, calcium compounds and the like. Of these, a titanium compound is particularly suitable. Specific examples of the titanium compound as an esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

The polybutylene terephthalate resin may be a polybutylene terephthalate resin modified by copolymerization (hereinafter, may be referred to as “modified polybutylene terephthalate resin”), and a specific preferable copolymer thereof is poly. Examples thereof include polyester ether resin copolymerized with alkylene glycols (particularly polytetramethylene glycol), dimer acid copolymerized polybutylene terephthalate resin, and isophthalic acid copolymerized polybutylene terephthalate resin.

When a polyester ether resin copolymerized with polytetramethylene glycol is used as the modified polybutylene terephthalate resin, 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 even more 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 a dimer acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, 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 to 20 mol% is more preferable, and 3 to 15 mol% is even more preferable. Such a copolymerization ratio tends to have an excellent balance between laser weldability, long-term heat resistance, and toughness, which is preferable.
When an isophthalic acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, 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 preferable, and 3 to 15 mol% is even more preferable. Such a copolymerization ratio tends to have an excellent balance between laser weldability, heat resistance, injection moldability and toughness, which is preferable.
Among the modified polybutylene terephthalate resins, polyester ether resins copolymerized with polytetramethylene glycol and isophthalic acid copolymerized polybutylene terephthalate resins are preferable.

The preferable content of these copolymers is 5 to 50% by mass, more 10 to 40% by mass, and particularly 15 to 30% by mass in the total amount of the thermoplastic polyester resin of 100% by mass.

The intrinsic viscosity of the polybutylene terephthalate resin is preferably 0.5 to 2 dl / g. From the viewpoint of formability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are more preferable. If the intrinsic viscosity is lower than 0.5 dl / g, 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 deteriorated. 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 resin may be appropriately selected and determined, but is usually 60 eq / ton or less, preferably 50 eq / ton or less, and more preferably 30 eq / ton or less. .. 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 the terminal carboxyl group is not particularly determined, but is usually 10 eq / ton in consideration of the productivity of producing the polybutylene terephthalate resin.

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

As the thermoplastic polyester resin, those containing the polybutylene terephthalate resin and the modified polybutylene terephthalate resin are also preferable. By containing a specific amount of the modified polybutylene terephthalate resin, the laser transmittance and the laser weldability are easily improved, which is preferable.
When the polybutylene terephthalate resin and the modified polybutylene terephthalate resin are contained, the content of the modified polybutylene terephthalate resin is preferably 10 to 100% by mass of the total of the polybutylene terephthalate resin and the modified polybutylene terephthalate resin. It is 70% by mass, more preferably 20 to 65% by mass, and even more preferably 30 to 60% by mass. If the content of the modified polybutylene terephthalate resin is less than 10% by mass, the laser welding strength tends to decrease, and if it exceeds 70% by mass, the moldability may be significantly reduced, which is not preferable.

Further, the thermoplastic polyester resin preferably contains a polybutylene terephthalate resin and a polyethylene terephthalate resin. It is preferable that the polyethylene terephthalate resin is contained in a specific amount because the laser transmittance and the laser weldability are easily improved.
When the polybutylene terephthalate resin and the polyethylene terephthalate resin are contained, the content of the polyethylene terephthalate resin is preferably 5 to 50% by mass with respect to the total of 100% by mass of the polybutylene terephthalate resin and the polyethylene terephthalate resin. It is more preferably 10 to 45% by mass, and even more preferably 15 to 40% by mass. If the content of the polyethylene terephthalate resin is less than 5% by mass, the laser welding strength tends to decrease, and if it exceeds 50% by mass, the moldability may be significantly reduced, which is not preferable.

The polyethylene terephthalate resin is a resin whose main constituent unit is an oxyethylene oxyterephthaloyl unit composed of terephthalic acid and ethylene glycol with respect to all constituent repeating units, and contains a constituent repeating unit other than the oxyethylene oxyterephthaloyl unit. May be good. 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 an acid or glycerin, trimethylolpropane, penta which has a trifunctional or tetrafunctional ester form performance such as tricarballylic acid, trimellitic acid, trimellitic acid and the like as a branching component. An alcohol having a trifunctional or tetrafunctional ester-forming ability such as erythrite is copolymerized with 1.0 mol% or less, preferably 0.5 mol% or less, and more preferably 0.3 mol% or less. There may be.

The ultimate viscosity of the polyethylene terephthalate resin 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 is preferably 3 to 50 eq / ton, particularly preferably 5 to 40 eq / ton, more preferably 10 to 30 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 composition, and the mechanical properties of the obtained laser welding member tend to be improved. When the concentration is 3 eq / ton or more, the heat resistance, the retention heat stability, and the hue of the laser welding member tend to be improved, which is preferable.
The terminal carboxyl group concentration of the polyethylene terephthalate resin is a value obtained 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. be.
As a method for adjusting the amount of the terminal carboxyl group, a method for adjusting the polymerization conditions such as the raw material charging ratio at the time of polymerization, the polymerization temperature, the depressurization method, the method for reacting the terminal blocking agent, and the like, any conventionally known method can be used. Just do it.

The thermoplastic polyester resin material may contain other resins or additives. Other resins or additives will be described later.
In the present invention, such a thermoplastic polyester resin material preferably has a melt volume rate (MVR; measured under the conditions of 250 ° C. and a load of 5 kg) of 10 cm ^3/10 minutes or more, and more preferably 15 cm ^3/10 . Use one that is more than a minute. When measuring under the conditions of 280 ° C. and a load of 2.16 kg, 20 cm ^3/10 minutes or more is preferable, and 30 cm ^3/10 minutes or more is more preferable. By using an MVR in such a range, good molding is performed even if the welding member has a thin portion of 2 mm or less, 1.5 mm or less, or even an extremely thin thin portion of 1 mm or less. You can ensure sex.

Further, the thermoplastic polyester resin material preferably has a crystallization temperature (Tc) of 190 ° C. or lower. That is, by controlling the crystallization temperature (Tc) to be low, the laser transparency can be further improved. 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 is usually 160 ° C, preferably 165 ° C or higher. The crystallization temperature (Tc) is measured by DSC, and the details thereof are as described in Examples.

Then, the thermoplastic polyester resin material 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 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.

Further, the injection rate defined as the resin material capacity per unit time of injection from the discharge nozzle of the injection molding machine into the mold cavity is preferably 10 to 300 cm ³ / sec, more preferably 15 to 200 cm ³ / sec. Preferably, 25 to 100 cm ³ / sec is more preferable, and 50 to 90 cm ³ / sec is particularly preferable. By setting the injection rate in such a range, it becomes easier to increase the laser transmittance of the anti-gate side portion of the member, and by adjusting the gate position, the transmittance of the welded portion in the member can be further increased. .. 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 traveling coefficient defined below is 100 to 1200 cm ³ / sec · cm. By setting the surface advance coefficient in such a range, it becomes easier to increase the laser transmittance of the part on the opposite side of the member, and by adjusting the gate position, the transmittance of the welded portion in the member can be further increased. can.
Surface advance coefficient: A value obtained by dividing the injection rate by the thickness of the mold cavity into which the resin material is injected. A preferable range of the surface advance coefficient is 200 to 1100 cm ³ / sec · cm, more preferably 250 to 1000 cm ³ / sec ·. cm, more preferably 300 to 950 cm ³ / sec · cm, and particularly preferably 400 to 900 cm ³ / sec · cm.

The laser welding member obtained by injection molding the thermoplastic polyester resin material is subjected to laser welding. The method of laser welding is not particularly limited and can be performed by a usual method. A molded body (first member) obtained by injection molding a thermoplastic polyester resin material is placed on the permeation side, and is in contact with the resin molded body (second member, adherend) of the mating material (particularly at least welding). By surface contacting the parts) and irradiating with laser light, the two types of molded products are welded and integrated into one molded product. The present invention is characterized in that a portion of the injection molding die at a distance of 15 mm or more from the gate is laser welded as a welding portion. It is necessary that at least a part of the laser welded part is separated from the gate by 15 mm or more, but it is preferable that 30% or more of the total area of the laser welded part is separated from the gate by 15 mm or more, and 50% or more is more. It is preferable that 70% or more is more preferable, and it is particularly preferable that all the laser welding sites are separated from the gate by 15 mm or more.

When the above-mentioned thermoplastic polyester resin material of the present invention is injection-molded, the laser transmittance fluctuates greatly depending on the part (position) of the molded body, the transmittance is poor at the part near the gate position, and the distance from the gate becomes long. It has been clarified by the study of the present inventor that it shows excellent transmittance. For example, as shown in the examples below, it can be seen that the laser transmittance is low at a portion where the distance from the gate is as short as 10 mm, whereas the transmittance increases as the distance increases. The degree of improvement in the transmittance depends on the composition of the thermoplastic polyester resin material used, the thickness of the laser-welded portion, the injection molding conditions, etc., but the one having a high transmittance (for example, the transmittance composition A to Table 2 in Examples described later). It has been found that D, particularly the transmissive material compositions A and B, can achieve extremely high transmittances in the 50% to 60% range, further in the 70% range, and in excess of 80%.
Further, this permeability is affected by the composition of the thermoplastic polyester resin material used, the thickness of the laser welding site, the injection molding conditions, etc., but in the present invention, the composition of the thermoplastic polyester resin material and the laser welding site are affected. Regardless of the thickness, injection molding conditions, etc., the laser processability is improved and strong laser welding is possible by setting the light transmittance of the laser light with a wavelength of 940 nm at the laser welding site to 30% or more. Will be.

The shape of the laser welding member is not limited, and the distance from the gate of the injection molding die is 15 mm or more, preferably 20 mm or more, more preferably 25 mm or more, still more preferably 30 mm or more, particularly preferably 35 mm or more, most preferably. The entire shape may be any as long as it has a welding portion at a position separated by 40 mm or more. Normally, since the welded portion is bonded to the mating material (another resin or a molded body of the same resin) and laser welded, the welded portion has a shape (for example, a plate shape) having at least a contact surface (flat surface, etc.). .. The thickness of the laser welded portion (the portion irradiated with the laser) can be selected from a wide range, preferably 0.1 to 2 mm, more preferably 0.3 to 1.5 mm, and further 0.5 to 1 mm. ..

The size of the welding member is not limited, but for example, a three-dimensional shape can be regarded as a planar shape and can be arbitrarily set in the range of 2 cm × 2 cm to 50 cm × 50 cm, preferably 3 cm × 3 cm to 50 cm ×. It is preferably in the range of 50 cm, more preferably in the range of 3 cm × 3 cm to 40 cm × 40 cm, more preferably in the range of 3 cm × 3 cm to 35 cm × 35 cm, and particularly preferably in the range of 3 cm × 3 cm to 30 cm × 30 cm.
The number of gates may be plural, or a multi-point gate method may be used. The number of resin gates of the mold at the time of molding is preferably 4 pieces / 1 cm ² or less, more preferably 3 pieces / 1 cm ² or less, and 2 pieces / 1 cm ² or less with respect to the surface area of the plastic welding member. Is even more preferable.

The laser welding site preferably has a light transmittance of 35% or more, more preferably 40% or more, more preferably 45% or more, and further 50% or more in laser light having a wavelength of 940 nm. 55% or more, particularly 60% or more, particularly 65% or more, and most preferably 70% or more.
The thinner the thickness of the molded body, the higher the permeability. Therefore, in order to obtain the above-mentioned preferable permeability, the composition of the thermoplastic polyester resin material used, the thickness of the molded body, the distance from the gate of the injection molding mold, and the injection Molding conditions such as speed, injection rate, surface progress coefficient, resin temperature, and mold temperature may be appropriately adjusted so that the portion to be laser-welded has a higher transmission rate.
The transmittance in the present invention means the transmittance of laser light having a wavelength of 940 nm.

The crystallization temperature (Tc) of the laser welded portion is preferably 190 ° C. or lower, more preferably 188 ° C. or lower, still more preferably 185 ° C. or lower, particularly preferably 182 ° C. or lower, and most preferably 180 ° C. or lower. .. The lower limit is usually 160 ° C, preferably 165 ° C or higher. The method for measuring the crystallization temperature (Tc) is as described in Examples.

The welding portion of the welding member obtained by injection molding the thermoplastic polyester resin material and the mating member containing the laser light absorber are brought into surface contact or butt contact with each other, and usually, the welding is performed with high transmittance. By irradiating the laser beam from the member side, the interface between the two is at least partially melted and cooled to be integrated into one molded product.

The member on the other side containing the laser light absorber is not particularly limited as long as it is a member made of a thermoplastic resin composition that can absorb laser light and is melted by absorbing the laser light. .. Specific examples thereof include a member made of a resin composition usually containing carbon black or a laser-absorbing dye in order to enable absorption of laser light. The content of the absorbent such as carbon black is not particularly limited, but is preferably 0.2 to 1% by mass with respect to the resin composition, for example.

Preferred examples of the laser light-absorbing dye include niglocin, aniline black, phthalocyanine, naphthalocyanine, porphyrin, perylene, quoterylene, azo dye, anthraquinone, square acid derivative and immonium.
Of these, niglocin is particularly preferred. Niglosin is C.I. I. SOLVENT BLACK 5 and C.I. I. It is a black azine-based condensation mixture as described in COLOR INDEX as SOLVENT BLACK 7. Examples of commercially available products of niglocin include "NUBIAN (registered trademark) BLACK" (trade name, manufactured by Orient Chemical Industry Co., Ltd.) and the like.
The content of the laser light absorbing dye is 0.001 to 0.2 parts by mass, preferably 0.003 to 0.1 parts by mass, and more preferably 0.005 to 0 parts with respect to 100 parts by mass of the resin component. It is 0.05 parts by mass.

In order to obtain higher welding strength, it is preferable that both members are the above-mentioned thermoplastic polyester resin materials and the counterpart contains carbon black or a laser light absorbing dye. Since such a member has the same composition except for the presence or absence of carbon black or a laser light-absorbing dye, the welded transmissive resin member and the absorbent resin member are easily fitted and firmly fixed.

The type of laser light to be irradiated is arbitrary as long as it is near-infrared laser light, such as YAG (yttrium aluminum garnet crystal) laser (wavelength 1064 nm), LD (laser diode) laser (wavelength 808 nm, 840 nm, 940 nm), etc. Can be preferably used. In particular, laser light having a wavelength of 940 nm is preferable.

The shape, size, thickness, etc. of the molded product integrated by laser welding are arbitrary, and the welded body can be used for electrical components for transportation equipment such as automobiles, electrical and electronic equipment parts, industrial machine parts, and others. It is particularly suitable for consumer parts and the like.

As described above, the thermoplastic polyester-based resin material used in the present invention may contain other resins or additives.
Other resins can contain various thermoplastic resins, and examples thereof include polystyrene, butadiene rubber-containing polystyrene, aromatic vinyl resins such as acrylonitrile-styrene copolymers, and polycarbonate resins. In the present invention, in order to achieve high laser permeability, it is preferable to use at least one resin selected from the group consisting of polycarbonate resin and polystyrene and / or polystyrene containing butadiene rubber in combination with the thermoplastic polyester resin.

[Polycarbonate resin]
The thermoplastic polyester resin material preferably contains a thermoplastic polyester resin and a polycarbonate resin. By containing a specific amount of the polycarbonate resin, the laser weldability is easily improved, which is preferable.
The polycarbonate resin is a optionally branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound or a small amount of a polyhydroxy compound with phosgene or a carbonic acid diester. The method for producing the polycarbonate resin is not particularly limited, and conventionally known phosgene method (interfacial polymerization method) or melting method (transesterification method) can be used, but the melting method is used. , Preferred from the viewpoint of laser permeability and laser welding.

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, Examples thereof include hydroquinone, resorcinol, 4,4-dihydroxydiphenyl and the like, and bisphenol A is preferable. Further, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

Among the above-mentioned polycarbonate resins, the aromatic polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other aromatic dihydroxys are used. Aromatic polycarbonate copolymers derived from the compound are preferred. Further, it may be a copolymer mainly composed of an aromatic polycarbonate resin, such as a polymer having a siloxane structure or a copolymer with an oligomer. Further, two or more of the above-mentioned polycarbonate resins may be mixed and used.

To adjust the molecular weight of the polycarbonate resin, a monovalent aromatic hydroxy compound may be used, for example, m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long chain. Examples thereof include alkyl-substituted phenols.

The viscosity average molecular weight of the polycarbonate resin is preferably 5,000 to 30,000, more preferably 10,000 to 28,000, and even more preferably 14,000 to 24,000. If a material having a viscosity average molecular weight of less than 5,000 is used, the obtained welding member tends to have low mechanical strength. If it is higher than 30,000, the fluidity of the resin material may be deteriorated, the moldability may be deteriorated, or the laser weldability may be deteriorated. 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-equivalent mass average molecular weight Mw to the number average molecular weight Mn of the polycarbonate resin measured by gel permeation chromatography (GPC) is preferably 2 to 5, and is 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 the terminal hydroxy group of the polycarbonate resin is preferably 100 mass ppm or more, more preferably 200 mass ppm or more, still more preferably 400 mass ppm, from the viewpoint of thermal stability, hydrolysis stability, color tone and the like. As mentioned above, it is most preferably 500 mass ppm or more. However, it is usually 1,500 mass ppm or less, preferably 1,300 mass ppm or less, more preferably 1,200 mass ppm or less, and most preferably 1,000 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.

As described above, as the polycarbonate resin, the polycarbonate resin produced by the melt polymerization method is preferable from the viewpoint of laser transparency and laser welding.

In the melt polymerization method, a transesterification reaction between an aromatic dihydroxy compound and a carbonic acid diester is performed.
The aromatic dihydroxy compound is as described above.
On the other hand, examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate and di-tert-butyl carbonate; diphenyl carbonate; and diaryl carbonates such as substituted diphenyl carbonate such as ditril carbonate. Of these, diaryl carbonate is preferable, and diphenyl carbonate is particularly preferable. In addition, 1 type of carbonic acid diester may be used, and 2 or more types may be used in arbitrary combination and ratio.

The ratio of the aromatic dihydroxy compound to the carbonic acid diester is arbitrary as long as the desired polycarbonate resin can be obtained, but it is preferable to use an equimolar amount or more of the carbonic acid diester with respect to 1 mol of the dihydroxy compound, particularly 1.01 mol or more. It is more preferable to use it. The upper limit is usually 1.30 mol or less. By setting it in such a range, the amount of terminal hydroxy groups can be adjusted to a suitable range.

In the polycarbonate resin, the amount of the terminal hydroxy group tends to have a great influence on the thermal stability, the hydrolysis stability, the color tone and the like. Therefore, the amount of the terminal hydroxy group may be adjusted as necessary by any known method. In the transesterification reaction, usually, a polycarbonate resin having an adjusted amount of terminal hydroxy groups can be obtained by adjusting the mixing ratio of the carbonic acid diester and the dihydroxy compound, the degree of reduced pressure during the transesterification reaction, and the like. By this operation, the molecular weight of the normally obtained polycarbonate resin can also be adjusted.

When the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound is adjusted to adjust the amount of the terminal hydroxy group, the mixing ratio is as described above.
Further, as a more positive adjustment method, there is a method of separately mixing a terminal terminator at the time of reaction. Examples of the terminal terminator at this time include monohydric phenols, monovalent carboxylic acids, carbonic acid diesters and the like. In addition, one kind of terminal terminator may be used, or two or more kinds may be used in any combination and ratio.

When producing a polycarbonate resin by a melt polymerization method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Above all, it is preferable to use an alkali metal compound and / or an alkaline earth metal compound. Further, as an auxiliary, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound may be used in combination. As the transesterification catalyst, one type may be used, or two or more types may be used in any combination and ratio.

In the melt polymerization method, the reaction temperature is usually 100 to 320 ° C. The pressure during the reaction is usually a reduced pressure condition of 2 mmHg or less (267 Pa or less). As a specific operation, the melt polycondensation reaction may be carried out under conditions within this range while removing by-products such as hydroxy compounds.

The melt polycondensation reaction can be carried out by either a batch method or a continuous method. In the case of batch method, the order of mixing the reaction substrate, reaction medium, catalyst, additives and the like is arbitrary as long as a desired polycarbonate resin can be obtained, and an appropriate order may be set arbitrarily. However, considering the stability of the polycarbonate resin and the resin material containing the polycarbonate resin, it is preferable to carry out the melt polycondensation reaction in a continuous manner.

In the melt polymerization method, a catalyst deactivating agent may be used if necessary. As the catalyst deactivating agent, a compound that neutralizes the transesterification catalyst can be arbitrarily used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. As the catalyst deactivating agent, one type may be used, or two or more types may be used in combination in any combination and ratio.
The amount of the catalyst deactivating agent used is usually 0.5 equivalents or more, preferably 1 equivalent or more, and usually 10 equivalents or less, with respect to the alkali metal or alkaline earth metal contained in the ester exchange catalyst. It is preferably 5 equivalents or less. Further, it is usually 1 mass ppm or more, and usually 100 mass ppm or less, preferably 20 mass ppm or less, with respect to the polycarbonate resin.

When the thermoplastic polyester resin material contains the thermoplastic polyester resin and the polycarbonate resin, the content of the thermoplastic polyester resin is preferably 10 to 50 with respect to 100% by mass of the total of the thermoplastic polyester resin and the polycarbonate resin. It is by mass%, more preferably 15 to 45% by mass, still more preferably 20 to 40% by mass. If the content of the polycarbonate resin is less than 10% by mass, the laser welding strength tends to decrease, and if it exceeds 50% by mass, the moldability may be significantly reduced, which is not preferable.

[Aromatic vinyl resin]
The thermoplastic polyester resin material preferably contains a thermoplastic polyester resin and an aromatic vinyl resin.
The aromatic vinyl-based resin is a polymer containing an aromatic vinyl compound as a main component, and examples of the aromatic vinyl compound include styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene and the like. , Preferably styrene. Polystyrene (PS) is a typical example of the aromatic vinyl resin.
Further, as the aromatic vinyl-based resin, a copolymer obtained by copolymerizing an aromatic vinyl compound with another monomer can also be used. A typical example is an acrylonitrile-styrene copolymer obtained by copolymerizing styrene and acrylonitrile.

As the aromatic vinyl-based resin, a rubber-containing aromatic vinyl-based resin obtained by copolymerizing or blending a rubber component can also be preferably used. Examples of the rubber component include conjugated diene-based hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene, but butadiene-based rubber is preferably used in the present invention. Acrylic rubber components are also possible as rubber components, but they are not preferable because they are poor in toughness.
When the rubber component is copolymerized or blended, the amount of the rubber component is usually 1% by mass or more and less than 50% by mass in all the aromatic vinyl resin segments. The amount of the rubber component is preferably 3 to 40% by mass, more preferably 5 to 30% by mass, and further preferably 5 to 20% by mass.
As the rubber component-containing aromatic vinyl resin, rubber-containing polystyrene is preferable, butadiene rubber-containing polystyrene is more preferable, and high-impact polystyrene (HIPS) is further preferable from the viewpoint of toughness.

The aromatic vinyl resin preferably has a mass average molecular weight of 50,000 to 500,000, and more preferably 100,000 to 400,000, particularly 150,000 to 300,000. If the molecular weight is less than 50,000, bleed-out is observed in the molded product, decomposition gas is generated during molding, and it is difficult to obtain sufficient weld strength. If the molecular weight is larger than 500,000, sufficient fluidity is obtained. And it is difficult to improve the laser welding strength.

For the aromatic vinyl resin, the melt flow rate (MFR) measured at 200 ° C. and 98N is preferably 0.1 to 50 g / 10 minutes, and more preferably 0.5 to 30 g / 10 minutes. It is preferably 1 to 20 g / 10 minutes, and more preferably 1 to 20 g / 10 minutes. If the MFR is less than 0.1 g / 10 minutes, the compatibility with the thermoplastic polyester resin becomes insufficient, and the appearance of layer peeling may be poor during injection molding. Further, if the MFR is larger than 50 g / 10 minutes, the impact resistance is greatly lowered, which is not preferable.
In particular, in the case of polystyrene, the MFR is preferably 1 to 50 g / 10 minutes, more preferably 3 to 35 g / 10 minutes, and even more preferably 5 to 20 g / 10 minutes. In the case of polystyrene containing butadiene rubber, the MFR is preferably 0.1 to 40 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes, and more preferably 1 to 20 g / 10 minutes. More preferred.

When the thermoplastic polyester-based resin material contains the thermoplastic polyester resin and the aromatic vinyl-based resin, the content is the aromatic vinyl-based resin with respect to 100% by mass of the total of the thermoplastic polyester resin and the aromatic vinyl-based resin. The resin is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and even more preferably 20 to 40% by mass. If the content of the aromatic vinyl resin is less than 10% by mass, the laser welding strength tends to decrease, and if it exceeds 50% by mass, the heat resistance and heat discoloration may decrease, which is not preferable.

In particular, in the present invention, it is preferable that the thermoplastic polyester resin material contains a thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and a polycarbonate resin from the viewpoint of laser weldability.
The polycarbonate resin is as described above.
As the polystyrene, a homopolymer of styrene or another aromatic vinyl monomer such as α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene and the like are copolymerized in a range of, for example, 50% by mass or less. May be.

The polystyrene containing butadiene rubber is obtained by copolymerizing or blending a butadiene rubber component, and the amount of the butadiene rubber component is usually 1% by mass or more and less than 50% by mass, preferably 3 to 40% by mass, more. It is preferably 5 to 30% by mass, more preferably 5 to 20% by mass. As the butadiene rubber-containing polystyrene, high impact polystyrene (HIPS) is particularly preferable.
Among polystyrenes or polystyrenes containing butadiene rubber, polystyrene containing butadiene rubber is preferable, and high-impact polystyrene (HIPS) is particularly preferable.

The preferred mass average molecular weight and MFR of polystyrene or butadiene rubber-containing polystyrene are as described above.

When the thermoplastic polyester resin material contains a thermoplastic polyester resin, polystyrene and / or a butadiene rubber-containing polystyrene and a polycarbonate resin, the crystallization temperature (Tc) of the obtained thermoplastic polyester resin material is 190 ° C. or lower. Is preferable. That is, the laser permeability can be further improved by appropriately suppressing the transesterification reaction between the thermoplastic polyester resin and the polycarbonate resin and appropriately lowering the crystallization temperature. The crystallization temperature (Tc) is more preferably 188 ° C. or lower, still more preferably 185 ° C. or lower, particularly preferably 182 ° C. or lower, and most preferably 180 ° C. or lower. The lower limit is usually 160 ° C, preferably 165 ° C or higher.
The method for measuring the crystallization temperature (Tc) is as described above.

When the thermoplastic polyester resin material contains the thermoplastic polyester resin, polystyrene and / or the butadiene rubber-containing polystyrene and the polycarbonate resin, the content is as follows.
The content of the thermoplastic polyester resin is preferably 30 to 90% by mass, preferably 40 to 80% by mass, based on a total of 100% by mass of the thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and the polycarbonate resin. More preferably, 50 to 70% by mass is further preferable. If the content is less than 30% by mass, the heat resistance may decrease, and if it exceeds 90% by mass, the transmittance tends to decrease, which is not preferable.

The content of polystyrene and / or polystyrene containing butadiene rubber is preferably 1 to 50% by mass based on a total of 100% by mass of the thermoplastic polyester resin, polystyrene and / or polystyrene containing butadiene rubber and polycarbonate resin, and 3 to 3 to. 45% by mass is more preferable, and 5 to 40% by mass is further preferable. If the content is less than 1% by mass, the laser weldability and toughness may be poor, and if it exceeds 50% by mass, the heat resistance tends to be significantly lowered, which is not preferable.

The content of the polycarbonate resin is preferably 1 to 50% by mass, more preferably 3 to 45% by mass, based on a total of 100% by mass of the thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and the polycarbonate resin. 5 to 40% by mass is more preferable. If the content is less than 1% by mass, the laser weldability is lowered, the dispersion of polystyrene and / or the polystyrene containing butadiene rubber is poor, and the surface appearance of the molded product is likely to be deteriorated. If it exceeds 50% by mass, transesterification with the thermoplastic polyester resin proceeds, and the retention heat stability may decrease, which is not preferable.

Further, the total content of polystyrene and / or butadiene rubber-containing polystyrene and the polycarbonate resin shall be 10 to 55% by mass in the total 100% by mass of the thermoplastic polyester resin, polystyrene and / or the butadiene rubber-containing polystyrene and the polycarbonate resin. Is preferable, 20 to 50% by mass is preferable, and 25 to 45% by mass is more preferable. With such a content, the balance between heat resistance and laser transmittance tends to be excellent, which is preferable.

Further, the content ratio of polystyrene and / or butadiene rubber-containing polystyrene and the polycarbonate resin component is preferably 5: 1 to 1: 5 by mass ratio, and more preferably 4: 1 to 1: 4. With such a content ratio, the balance between heat resistance and laser transmittance tends to be excellent, which is preferable.

[Other ingredients]
The thermoplastic polyester resin material used in the present invention may contain various additives as long as the effects of the present invention are not impaired. Such additives include stabilizers, mold release agents, reinforced fillers, flame retardants, flame retardant aids, dripping inhibitors, UV absorbers, antistatic agents, antifogging agents, lubricants, antiblocking agents, and plasticizers. Agents, dispersants, antibacterial agents and the like can be mentioned.

The thermoplastic polyester resin material used in the present invention preferably contains a flame retardant. There are various flame retardants such as halogen-based flame retardants, phosphorus-based flame retardants (polyphosphate melamine, etc.), nitrogen-based flame retardants (cyanurate melamine, etc.), and metal hydroxides (magnesium hydroxide, etc.). In the present invention, as the halogen-based flame retardant, a brominated flame retardant is preferable, a brominated polycarbonate, a brominated epoxy compound, a brominated poly (meth) acrylate and the like are more preferable, and a brominated polycarbonate-based flame retardant is particularly contained. Is preferable. Normally, the transmittance is lowered when a halogen-based flame retardant is contained, but by containing a brominated polycarbonate-based flame retardant in combination with a nickel-containing colorant described later, good flame retardancy and laser Both light transmittance can be achieved, and the obtained molded body has low warpage, which enables strong laser welding in a short welding time.
It is considered that such an effect is also due to the fact that the brominated polycarbonate-based flame retardant phase disperses in the surface layer portion of the obtained molded product without stretching as much as other flame retardants. The ratio of the major axis to the minor axis of the brominated polycarbonate flame retardant phase on the surface layer is small, and the internal scattering of the laser beam is small, so the transmittance is considered to be high.

As the brominated polycarbonate-based flame retardant, those conventionally known as brominated polycarbonate-based flame retardants can be used, and specifically, for example, brominated polycarbonate obtained from brominated bisphenol A, particularly tetrabromobisphenol A. Is preferable. Examples of the terminal structure include a phenyl group, a 4-t-butylphenyl group, a 2,4,6-tribromophenyl group and the like, and in particular, those having a 2,4,6-tribromophenyl group in the terminal group structure. Is preferable.

The average number of repeating units of carbonate in the brominated polycarbonate-based flame retardant may be appropriately selected and determined, but is usually 2 to 30. If the average number of carbonate repeating units is small, it may cause a decrease in the molecular weight of the thermoplastic polyester resin during melting. On the contrary, if it is too large, it may cause poor dispersion in the molded product, and the appearance of the molded product, particularly the glossiness, may be deteriorated. Therefore, the average number of repeating units is preferably 3 to 15, particularly preferably 3 to 10.

The molecular weight of the brominated polycarbonate-based flame retardant is arbitrary and may be appropriately selected and determined, but the viscosity average molecular weight is preferably 1,000 to 20,000, more preferably 1,500 to 15,000. It is preferably 1,500 to 10,000.
The viscosity average molecular weight of the brominated polycarbonate-based flame retardant was determined by measuring the viscosity of the methylene chloride solution of the brominated polycarbonate resin at 20 ° C. using a Ubbelohde viscometer to determine the ultimate viscosity ([η]). The value calculated from the viscosity formula of Schnell is shown.
[Η] = 1.23 × 10 ^-4 Mv ^0.83

The brominated polycarbonate-based flame retardant obtained from the brominated bisphenol A can be obtained, for example, by a usual method of reacting brominated bisphenol with phosgene. Examples of the terminal sequestering agent include aromatic monohydroxy compounds, which may be substituted with halogens or organic groups.

The content of the brominated polycarbonate-based flame retardant is preferably 20 to 70 parts by mass, more preferably 25 parts by mass or more, still more preferably 30 parts by mass or more, and particularly preferably 30 parts by mass or more, based on 100 parts by mass of the thermoplastic polyester resin. It is 35 parts by mass or more, particularly preferably 40 parts by mass or more, more preferably 65 parts by mass or less, further preferably 60 parts by mass or less, and particularly preferably 55 parts by mass or less. If the content of the brominated polycarbonate flame retardant is too small, the flame retardancy of the thermoplastic polyester resin material becomes insufficient, and the laser light transmittance and laser weldability are inferior. Problems of deterioration of moldability and bleed-out of flame retardant occur.

In the present specification, the brominated polycarbonate-based flame retardant is different from the above-mentioned polycarbonate resin, and is not included in the polycarbonate resin.

The thermoplastic polyester resin material used in the present invention preferably contains a nickel-containing colorant as a colorant. By containing a nickel-containing colorant in combination with a brominated polycarbonate-based flame retardant, laser light transmission is good, strong laser welding is possible in a short welding time, and further, low warpage is excellent. It was also found that the inclusion of a nickel-containing colorant improves flame retardancy.

As the nickel-containing colorant, among various dyes (including pigments), a dye containing nickel is used, preferably a metal complex salt dye or a metal-containing dye, and a dye formed by forming a complex salt with nickel. Is preferable. Examples of the functional group of the complex salt dye forming a complex salt with nickel include a hydroxyl group, a carboxyl group, an amino group and the like. Azo compounds having a functional group, azomethine compounds and the like can be preferably mentioned. Taking a monoazo dye as an example, a 1: 1 type metal complex salt dye in which a Ni1 atom is coordinated to one molecule of the monoazo dye and a 1: 2 type in which a Ni1 atom is coordinated to two molecules of the monoazo dye (base material). There is a metal complex salt dye.

As a nickel-containing colorant, C.I. I. SOLVENT Brown 53 is particularly preferably mentioned, and its chemical name is [2,3'-Bis [[(2-hydroxyphenyl) methylene] amino] but-2-endinirilateto (2-) -N2, N3, O2, O3] nickel. The chemical structural formula is shown below.

In addition, C.I. I. SOLVENT Brown 53 is also commercially available as a masterbatch, and it is also preferable to use eBIND LTW-8950H (trade name manufactured by Orient Chemical Industry Co., Ltd.), which is a masterbatch with a polybutylene terephthalate resin.

The nickel content in the nickel-containing colorant is preferably 1 to 40% by mass, preferably 5% by mass or more, more preferably 10% by mass or more, preferably 30% by mass or less, and more preferably 20% by mass. It is less than mass%. If it is less than the above lower limit, the effect of improving flame retardancy may not be sufficient, and heat-resistant discoloration tends to occur. Further, if the upper limit value is exceeded, the blackness may be insufficient when the color tone is adjusted to black.

The content of the nickel-containing colorant is preferably 0.01 to 5 parts by mass, more preferably 0.03 parts by mass or more, and further preferably 0.06 parts by mass or more with respect to 100 parts by mass of the thermoplastic polyester resin. It is particularly preferably 0.1 part by mass or more, more preferably 3 parts by mass or less, further preferably 2 parts by mass or less, and particularly preferably 1 part by mass or less. If it is less than the above lower limit, the effect of improving flame retardancy may not be sufficient, and heat-resistant discoloration tends to occur. If the above upper limit is exceeded, the blackness may be insufficient when the color is adjusted to black.
The nickel content in the thermoplastic polyester resin material is preferably 0.001 to 1% by mass, more preferably 0.003% by mass or more, still more preferably 0.006% by mass or more, and particularly preferably 0.006% by mass or more. It is 0.01% by mass or more, more preferably 0.8% by mass or less, further preferably 0.5% by mass or less, particularly preferably 0.3% by mass or less, and most preferably 0.1% by mass or less. .. If it is below the above lower limit, the effect of improving flame retardancy may not be sufficient, and if it exceeds the above upper limit, the blackness may be insufficient when the color is adjusted to black.

The thermoplastic polyester resin material used in the present invention may also contain an antimony compound in order to further improve the flame retardancy. However, since the inclusion of the antimony compound leads to a decrease in laser light transmission, it is preferable that the content of the antimony compound does not exceed 1% by mass in the resin composition.

Preferred examples of the antimony compound include antimony trioxide (Sb ₂ O ₃ ), antimony pentoxide (Sb ₂ O ₅ ) and sodium antimonate. Among these, antimony trioxide is preferable from the viewpoint of impact resistance.

When the antimon compound is contained, the mass concentration of the bromine atom derived from the brominated polycarbonate flame retardant and the antimon atom derived from the antimon compound in the resin composition is 3 to 25% by mass in total. It is preferably 4 to 22% by mass, more preferably 7 to 20% by mass. If it is less than 3% by mass, the flame retardancy tends to decrease, and it exceeds 20% by mass. The mass ratio (Br / Sb) of the bromine atom to the antimony atom is preferably 1 to 15, more preferably 3 to 13, and 7 to 11. It is more preferable that the range is set to such a range, because the decrease in the laser transmittance is small and the laser weldability and the flame retardancy tend to be compatible with each other.

When the antimony compound is contained, it is preferable to blend it as a masterbatch with a thermoplastic polyester resin. As a result, the (E) antimony compound tends to be present in the thermoplastic polyester resin phase, and the decrease in impact resistance tends to be suppressed.
The content of the antimony compound in the masterbatch is preferably 20 to 90% by mass. When the amount of the antimony compound is less than 20% by mass, the proportion of the antimony compound in the flame retardant masterbatch is small, and the effect of further improving the flame retardancy on the thermoplastic polyester resin containing the antimony compound is small. On the other hand, when the amount of the antimony compound exceeds 90% by mass, the dispersibility of the antimony compound tends to decrease, and when this is blended with the thermoplastic polyester resin, the flame retardancy of the resin composition becomes unstable, and masterbatch production also occurs. Workability at the time is also significantly reduced, for example, when manufacturing using an extruder, problems such as unstable strands and easy breakage are likely to occur, which is not preferable.
The content of the antimony compound in the masterbatch is preferably 30 to 85% by mass, more preferably 40 to 80% by mass, and further preferably 50 to 80% by mass.

When the antimony compound is contained, the content is preferably 1 part by mass or less, more preferably 0.05 part by mass or more, and further preferably 0. It is 1 part by mass or more, more preferably 0.8 part by mass or less, further preferably 0.6 part by mass or less, and particularly preferably 0.4 part by mass or less. With such a content, the laser transmittance is unlikely to decrease, and the balance between laser weldability and flame retardancy tends to be excellent.

[Stabilizer]
The thermoplastic polyester resin material preferably contains a stabilizer.
Examples of the stabilizer include various stabilizers such as phosphorus-based stabilizers, sulfur-based stabilizers, and phenol-based stabilizers. Particularly preferred are phosphorus-based stabilizers and phenol-based stabilizers.

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, and an organic phosphate compound is particularly preferable. ..

The organic phosphate compound is preferably given the following general formula:
(R ¹ O) _3-n P (= O) OH _n
(In the formula, 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.)
It is a compound represented by.

In the above general formula, R ¹ is an alkyl group having 1 or more carbon atoms, preferably 2 or more carbon atoms, usually 30 or less, preferably 25 or less, or an aryl group having 6 or more carbon atoms and usually 30 or less carbon atoms. Although more preferable, R ¹ is preferably an alkyl group rather than an aryl group. When two or more R ^1s are present, the R ^1s may be the same or different from each other.
More preferably, a long-chain alkyl acid phosphate compound in which R ¹ has 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 and a tetradecyl group. Examples thereof include a hexadecyl group, an octadecyl group, an eicosyl group, and a triacontyl group.

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, distealyl acid phosphate, diphenyl acid phosphate, bisnonylphenyl acid phosphate and the like. Among these, octadecyl acid phosphate is preferable, and this product is commercially available under the trade name "ADEKA STAB AX-71" of ADEKA.

By blending the phosphorus-based stabilizer represented by the above general formula, particularly when the thermoplastic polyester resin and the polycarbonate resin are contained, the ester exchange reaction between the two is appropriately suppressed, and the crystals of the thermoplastic polyester-based resin material are crystallized. The conversion temperature tends to be 190 ° C. or lower, which makes it easier to improve the laser permeability and the laser weldability.

The content of the phosphorus-based stabilizer is preferably 0.001 to 1 part by mass with respect to 100 parts by mass in total of the thermoplastic polyester resin and other resins contained if necessary. If the content of the phosphorus-based stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in the thermal stability and compatibility of the welding member, and the molecular weight during molding and the deterioration of hue are likely to occur by 1 mass. If the amount exceeds the portion, the amount becomes excessive and the generation of silver and the deterioration of hue tend to occur more easily. The content of the phosphorus-based stabilizer is more preferably 0.01 to 0.6 parts by mass, and further preferably 0.05 to 0.4 parts by mass.

As the phenol-based stabilizer, a hindered phenol-based stabilizer is preferable, and for example, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,) 5-Di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexane-1,6 -Diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (3,5-bis) 1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphate, 3,3', 3 ", 5,5', 5" -hexa-tert-butyl-a, a', a "-(methicylene-) 2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylene bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy- m-tryl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert-butyl- 4-Hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio)) -1,3,5-triazine-2-ylamino) phenol, 2- [1- (2-hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate And so on.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate are among them. preferable. Specific examples of such phenolic antioxidants include, for example, "Irganox 1010" and "Irganox 1076" manufactured by BASF (trade name, the same applies hereinafter), and "ADEKA STUB AO-50" manufactured by ADEKA. Examples thereof include "ADEKA STUB AO-60".
The hindered phenol-based stabilizer may contain one kind or two or more kinds in any combination and ratio.

The content of the phenol-based stabilizer is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the thermoplastic polyester resin and other resins contained if necessary. If the content is less than 0.01 parts by mass, the thermal stability tends to decrease, and if it exceeds 1 part by mass, the laser transmittance may decrease. A more preferable content is 0.05 to 0.8 parts by mass, and even more preferably 0.1 to 0.6 parts by mass.

In the present invention, it is preferable to use a phosphorus-based stabilizer represented by the above general formula and a phenol-based stabilizer in combination from the viewpoints of retention characteristics, heat resistance, laser transmittance, and laser weldability.

[Release agent]
The thermoplastic polyester-based resin material preferably further contains a mold release agent. As the release agent, known release agents usually used for polyester resins can be used, and among them, one or more release agents selected from polyolefin-based compounds, fatty acid ester-based compounds, and silicone-based compounds are used. preferable.

Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax, and among them, those having a mass average molecular weight of 700 to 10,000, more preferably 900 to 8,000 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 partially saponified products thereof. Among them, the number of carbon atoms is 11 to 28, preferably carbon atoms. Mono- or di-fatty acid esters composed of fatty acids of numbers 17-21 are preferred. Specific examples thereof include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxymonostearate, sorbitan monobehenate, pentaerythritol distearate, and pentaerythritol tetrastearate.

Further, as the silicone-based compound, a modified compound is preferable from the viewpoint of compatibility with the thermoplastic polyester resin and the like. Examples of the modified silicone oil include silicone oil having an organic group introduced in the side chain of polysiloxane, and silicone oil having an organic group introduced into both ends and / or one end of the polysiloxane. Examples of the organic group to be introduced include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacrylic 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 in total of the thermoplastic polyester resin and other resins contained if necessary. 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 material is deteriorated and the molded product is formed. Cloudiness may be seen on the surface. The content of the release agent is preferably 0.1 to 1.5 parts by mass, more preferably 0.3 to 1.0 part by mass.

[Reinforced filler]
The thermoplastic polyester-based resin material also preferably contains a reinforced filler.
As the reinforced filler, a commonly used inorganic filler for plastics can be used. Fibrous fillers such as glass fiber, carbon fiber, basalt fiber, wollastonite, and potassium titanate fiber can be preferably used. Granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organic clay, glass beads; plate-like fillers such as talc; scale-like fillers such as glass flakes, mica, graphite. Wood can also be used.
Among them, it is preferable to use glass fiber from the viewpoint of laser light transmission, mechanical strength, rigidity and heat resistance.

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 the surface treatment agent, a novolak type epoxy resin, a bisphenol A type epoxy resin and the like are also preferably mentioned. Of these, bisphenol A type epoxy resin is preferable.
The silane-based surface treatment agent and the epoxy resin 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 weldability, the glass fiber is preferably a glass fiber having an irregular 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 oval, oval, or eyebrows, and particularly preferably oval. Further, the major axis / minor axis ratio is preferably in the range of 2.5 to 8, and more preferably in the range of 3 to 6. Further, when the major axis of the cross section of the glass fiber in the molded product is D2, the minor axis is D1, and the average fiber length is L, the aspect ratio ((L × 2) / (D2 + D1)) is preferably 10 or more. The use of such flat glass fibers suppresses warpage of the molded product, and is particularly effective in producing a box-shaped welded body.

The content of the reinforcing filler is 0 to 100 parts by mass with respect to 100 parts by mass in total of the thermoplastic polyester resin and other resins contained if necessary. If the content of the reinforcing filler exceeds 100 parts by mass, the fluidity and laser welding property are lowered, which is not preferable. The content of the reinforced filler is more preferably 5 to 90 parts by mass, more preferably 15 to 80 parts by mass, still more preferably 20 to 70 parts by mass, and particularly preferably 30 to 60 parts by mass.

[Manufacturing of thermoplastic polyester resin materials]
The method for producing the thermoplastic polyester-based resin material 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 and then melt-kneaded in a uniaxial or twin-screw extruder. Further, it is also possible to prepare the resin material of the present invention without mixing each component in advance or by mixing only a part thereof in advance and supplying the mixture to an extruder using a feeder for melt-kneading.
Furthermore, a masterbatch is prepared by melt-kneading a mixture of a part of a thermoplastic polyester resin and other resins contained as necessary with a part of other components, and then the rest. Ingredients may be mixed 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.

The laser-welded molded body obtained by molding the thermoplastic polyester resin material used in the present invention preferably forms a continuous matrix phase of the thermoplastic polyester resin on the surface layer portion of the molded body, and is difficult to use for brominated polycarbonate. The fuel phase is dispersed in the continuous phase of the thermoplastic polyester resin, and the ratio of the major axis to the minor axis (major axis / minor axis) of the brominated polycarbonate-based flame retardant phase is preferably in the range of 1 to 5. Since the brominated polycarbonate-based flame retardant phase disperses without stretching as much as other flame retardants, it is considered that the small ratio between the major axis and the minor axis results in less internal scattering of laser light and better laser light transmission. Be done. The major axis / minor axis ratio is more preferably 1.2 to 4, still more preferably 1.4 to 3.

Observation of the morphology of such a molded body can be measured by observing the cross section of the molded body with an optical microscope, SEM (scanning electron microscope), TEM (transmission electron microscope), etc., and preferably a scanning electron microscope (scanning electron microscope). Observed by SEM).
Specifically, using an SEM / EDS analyzer, the surface of the molded body (depth less than 20 μm) is observed with a backscattered electron image at a magnification of 1,500 to 100,000 times under an acceleration voltage of 1.5 to 2 kV. To.

FIG. 3 shows an example of the morphology of the molded body of the present invention, and is a photograph of a backscattered electron image obtained by SEM / EDS analysis of the surface layer portion of the molded body obtained in Example 20 below (magnification: 3,000 times). ). In FIG. 3, the black-gray continuous phase (matrix phase) is composed of the polybutylene terephthalate resin phase, and the slightly pale white flat phase is the dispersed phase of the brominated polycarbonate flame retardant. It is confirmed that the brominated polycarbonate flame retardant is dispersed in the continuous phase of the polybutylene terephthalate resin.

The major axis and minor axis of the brominated polycarbonate flame retardant phase can be read by emphasizing the contrast, adjusting the brightness or adjusting both of the images obtained from the backscattered electron image, and brominated. The length of 50 or more of the polycarbonate-based flame retardant phase is measured, and the major axis / minor axis is calculated from the average value. The major axis means the maximum length of the flame retardant phase, and the minor axis means the shortest diameter among the lengths perpendicular to the major axis. The ratio of the major axis to the minor axis (major axis / minor axis) of the brominated polycarbonate-based flame retardant phase of Reference Example 1 was 2.7.

By having the peculiar morphology structure as described above, a molded product having excellent laser light transmittance, excellent balance between laser welding property and flame retardancy, and low warpage property can be obtained.
The thermoplastic polyester-based resin material used in the present invention is preferably produced by a melt-kneading method using a melt-kneader such as an extruder. However, simply mixing and kneading the raw material components has the above-mentioned morphology structure. It is difficult to form stably, and it is recommended to knead by a special method.
Hereinafter, a preferable production method for stably forming such a morphological structure when the thermoplastic polyester resin contains polybutylene terephthalate resin as a main component will be described.

Polybutylene terephthalate resin, brominated polycarbonate flame retardant, nickel-containing colorant and other components to be blended as needed are mixed in a predetermined ratio and then supplied to a single-screw or twin-screw extruder equipped with a die nozzle. After that, the resin composition is melt-kneaded and extruded from a die nozzle to form a strand, which is then cut to produce pellets.
At this time, it is preferable to use a twin-screw extruder as the melt-kneader. Above all, it is preferable that L / D, which is the ratio of the screw length L (mm) to the diameter D (mm) of the screw, satisfies the relationship of 15 <(L / D) <100, and 20 <(L). / D) It is more preferable to satisfy <80. When the ratio is 15 or less, the major axis / minor axis ratio of the brominated polycarbonate flame retardant phase in the surface layer of the molded body is unlikely to be in the range of 1 to 5, and conversely, even when the ratio is 100 or more, the heat of the brominated polycarbonate flame retardant is high. It is not preferable because deterioration may be significant.
The shape of the die nozzle is not particularly limited, but a circular nozzle having a diameter of 1 to 10 mm is preferable, and a circular nozzle having a diameter of 2 to 7 mm is more preferable in terms of the pellet shape.

In addition, when supplying raw materials to a melt-kneader such as an extruder, a brominated polycarbonate-based flame retardant, a nickel-containing colorant, and other components to be blended as necessary are blended in advance before melt-kneading. It is preferable to supply this preliminary blend from a feeder provided separately from the polybutylene terephthalate resin to a melt kneader such as an extruder. When a nickel-containing colorant is blended as a master touch, it should be pre-blended with polybutylene terephthalate resin and supplied to a melt kneader such as an extruder from a separate feeder with a pre-blend of other components. Is preferable. By adopting such a supply method, the major axis / minor axis ratio of the brominated polycarbonate-based flame retardant phase in the surface layer of the molded body tends to be in the range of 1 to 5, and it becomes easier to achieve both laser weldability and flame retardancy. preferable.

The melting temperature of the resin composition during melt-kneading is preferably 200 to 330 ° C, more preferably 220 to 315 ° C. If the melting temperature is less than 200 ° C., the melting is insufficient and unmelted gel is likely to occur frequently. On the contrary, if the melting temperature exceeds 330 ° C., the resin composition is thermally deteriorated and easily colored, which is not preferable.

The screw rotation speed during melt kneading is preferably 50 to 1,200 rpm, more preferably 80 to 1,000 rpm. When the screw rotation speed is less than 50 rpm, the major axis / minor axis ratio of the brominated polycarbonate flame retardant phase in the surface layer of the molded body tends to be difficult to be in the range of 1 to 5, and when it exceeds 1,200 rpm, an antimony compound is contained. In this case, the antimony compound tends to aggregate, and the laser light transmittance and mechanical properties may deteriorate, which is not preferable.
The discharge amount is preferably 10 to 2,000 kg / hr, more preferably 15 to 1,800 kg / hr. When the discharge amount is within the above range, the major axis / minor axis ratio of the brominated polycarbonate flame retardant phase in the surface layer of the molded body tends to be in the range of 1 to 5, and when the antimony compound is contained, it is due to the aggregation of the ammon compound. It is preferable that the laser light transmittance and the mechanical properties are less likely to deteriorate.

The shear rate of the resin composition in the die nozzle is preferably 50 to 10,000 sec ^-1 , more preferably 70 to 5,000 sec ^-1 , and even more preferably 100 to 1,000 sec ^-1 . .. The shear rate is generally determined from the discharge amount of the resin composition and the shape of the cross section of the die nozzle. For example, when the cross section of the die nozzle is circular, it can be calculated by γ = 4Q / ^πr3 . can. Here, γ represents the shear rate (sec ^-1 ), Q represents the discharge amount of the resin composition per die nozzle (cc / sec), and r represents the radius of the cross section of the die nozzle (cm).

The resin composition extruded into a strand shape from the die nozzle is cut into a pellet shape by cutting with a pelletizer or the like, but in the present invention, the surface temperature of the strand at the time of cutting is preferably 30 to 150 ° C., more preferably 35 to 135. It is preferable to cool the strands to ° C, more preferably 40 to 110 ° C, and particularly preferably 45 to 100 ° C. It is usually cooled by a method such as air cooling or water cooling, but water cooling is preferable from the viewpoint of cooling efficiency. In such water cooling, the strand may be cooled by passing it through a water tank containing water, and the desired strand surface temperature can be obtained by adjusting the water temperature and the cooling time. The shape of the pellet thus produced is preferably 1 to 9 mm in diameter, more preferably 2 to 8 mm, still more preferably 3 to 6 mm, and preferably 1 to 11 mm in length in the case of a columnar shape. Is 2 to 8 mm, more preferably 3 to 6 mm.

Further, the relationship between the shear rate γ (sec ^-1 ) in the die nozzle and the surface temperature T (° C.) of the strand at the time of cutting the strand is determined.
1.5 × 10 ³ <(γ ・ T) <1.5 × 10 ⁶
By satisfying the above relationship, the major axis / minor axis ratio of the brominated polycarbonate-based flame retardant phase in the surface layer of the molded body tends to be in the range of 1 to 5, and both laser welding and flame retardancy can be more easily achieved. Further, when the value of (γ · T) is 1.5 × ¹⁰³ or less, the surface of the molded product is liable to cause a rough skin phenomenon due to poor dispersion of each component of the resin composition, and the laser light transmittance, flame retardancy, and the like. Mechanical properties tend to be unstable. On the contrary, even if it exceeds 1.5 × ¹⁰⁶ , if the antimony compound is contained, the antimony compound may aggregate and the laser light transmittance and the mechanical properties may deteriorate, which is not preferable. The lower limit of (γ · T) is more preferably 3.3 × ^{10 3} , and the upper limit is more preferably 9.5 × 105.
In order to adjust the value of (γ · T) to the above range, the above shear rate and the surface temperature of the strand may be adjusted.

In the present invention, the thermoplastic polyester resin material having the above-mentioned morphological structure can be produced by applying the above-mentioned preferable conditions alone or in combination of a plurality of them. Among them, (γ · T) It is effective to adopt manufacturing conditions such that the value of is satisfied by the above formula.

By adopting such a method for producing a thermoplastic polyester resin material, it becomes easy to stably produce a laser welded molded article having the above-mentioned morphology structure. However, the method for producing a molded product having the above-mentioned morphology structure is not limited to such a method, and other methods may be used as long as the above-mentioned preferable morphology structure can be obtained.

Further, in order to stably and easily form the molded body having the above-mentioned morphology structure, the molded body is manufactured by using the thermoplastic polyester resin composition to which the following methods and conditions 1) to 3) are applied. It is also preferable.

1) When an antimony compound is contained, antimony trioxide is used and blended as a masterbatch with a thermoplastic polyester resin. This facilitates the stable formation of the preferred morphological structure described above.

2) The content of the chlorine compound, which is an impurity in the brominated polycarbonate-based flame retardant, is usually 0.3% by mass or less, preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and further 0. It is preferably 0.08% by mass or less, particularly 0.03% by mass or less. By controlling in this way, it becomes easy to stably form the above-mentioned preferable morphological structure.
The chlorine compound which is an impurity is, for example, a chlorinated bisphenol compound or the like, and when the chlorinated bisphenol compound is present in the above amount or more, it becomes difficult to stably form the preferable morphological structure of the present invention. The chlorine compound content can be quantified as a decan-equivalent value by analyzing the gas generated by heating at 270 ° C. for 10 minutes by a gas chromatography method.

3) It is also effective to reduce the amount of free bromine, chlorine and sulfur in the thermoplastic polyester resin material to a specific amount or less in order to facilitate the stable formation of a preferable morphological structure. The amount of free bromine is preferably 800 mass ppm or less, more preferably 700 mass ppm or less, further preferably 650 mass ppm or less, and particularly preferably 480 mass ppm or less. Further, since removing the content to 0 mass ppm requires purification that disregards economic efficiency, the lower limit thereof is usually 1 mass ppm, preferably 5 mass ppm, and more. It is preferably 10 mass ppm.
The amount of free chlorine is preferably 500 mass ppm or less, more preferably 350 mass ppm or less, further preferably 200 mass ppm or less, and particularly preferably 150 mass ppm or less. The chlorine content in the thermoplastic polyester resin material is not limited to the state and form in which chlorine is present in the resin composition. Chlorine is mixed in from various environments such as raw materials used, additives, catalysts, polymerization atmospheres, and cooling water for resins, and it is preferable to control the total amount of chlorine mixed in to 500 mass ppm or less.
The amount of free sulfur is preferably 250 mass ppm or less, more preferably 200 mass ppm or less, further preferably 150 mass ppm or less, and particularly preferably 100 mass ppm or less. The sulfur content in the thermoplastic polyester resin material is not limited to the state and form in which sulfur is present in the resin composition. Since sulfur is mixed from various environments such as raw materials used, additives, catalysts, and polymerization atmosphere, it is preferable to control the total amount of sulfur mixed to 250 mass ppm or less.

The contents of free bromine, chlorine, and sulfur in the thermoplastic polyester resin material can be measured by a combustion ion chromatography method. Specifically, the resin composition was heated at 270 ° C. for 10 minutes in an argon atmosphere using an automatic sample combustion device of "AQF-100 type" manufactured by Mitsubishi Chemical Analytech Co., Ltd., and the generated bromine, chlorine, and the like were generated. The amount of sulfur can be determined by quantifying it using "ICS-90" manufactured by Nippon Dionex Corporation.

The methods and conditions 1) to 3) are preferably applied individually or in combination of a plurality of them, and can be further applied by applying them in combination with the above-mentioned production conditions of the thermoplastic polyester resin material. Become.

In injection molding, in order to obtain a molded body having the above-mentioned preferable morphology structure, for example, the screw configuration of the injection molding machine, the processing of the screw and the inner wall of the cylinder, the nozzle diameter, the selection of molding machine conditions such as the mold structure, and plastic molding. Various methods such as conversion, weighing, adjustment of molding conditions at the time of injection, addition of other components to the molding material, and the like can be mentioned. In particular, it is preferable to adjust, for example, the cylinder temperature, back pressure, screw rotation speed, injection speed, etc. as conditions for plasticization, weighing, and injection. For example, when adjusting the cylinder temperature, it is preferably set to 230 to 280 ° C, more preferably 240 to 270 ° C. When adjusting the back pressure, it is preferably set to 2 to 15 MPa, more preferably 4 to 10 MPa. When adjusting the screw rotation speed, it is preferably set to 20 to 300 rpm, more preferably 20 to 250 rpm. When adjusting the injection speed, it is preferably set to 5 to 1,000 mm / sec, more preferably 10 to 900 m / sec, still more preferably 20 to 800 mm / sec, and 30 to 500 mm / sec.

The obtained molded body of the thermoplastic polyester resin material is subjected to laser welding. The method of laser welding is not particularly limited and can be performed by a usual method. The molded body (first member) of the thermoplastic polyester resin material is placed on the transmission side, and the resin molded body (second member, adherend) of the mating material is brought into contact (particularly, at least the welded portion is in surface contact). By irradiating with laser light, two types of molded products are welded and integrated into one molded product.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not construed as being limited to the following examples.
The components used in the following Examples and Comparative Examples are as shown in Table 1 below.

[Manufacturing of welding laser transmission material]
Each component listed in Table 1 above is blended in an amount (both parts by mass) described as the transmission material compositions A to G in Table 2 below, and this is blended at 250 ° C. using a 30 mm vent type twin-screw extruder. The mixture was kneaded and extruded into strands to obtain pellets having a transmission material composition A to G.
The crystallization temperature (Tc) of the resin composition was measured at a heating rate of 20 ° C./min from 30 to 300 ° C. under a nitrogen atmosphere using a differential scanning calorimetry (DSC) machine (“Pyris Diamond” manufactured by PerkinElmer). The temperature was raised at 300 ° C., maintained at 300 ° C. for 3 minutes, and then measured as the peak top temperature of the exothermic peak observed when the temperature was lowered at a temperature lowering rate of 20 ° C./min.
The results are shown in Table 2.

Further, the obtained pellets were dried at 120 ° C. for 5 hours using a melt indexer manufactured by Takara Kogyo Co., Ltd., and then melted per unit time measured under the conditions of 250 ° C., a load of 5 kgf or 280 ° C., and a load of 2.16 kgf. The flow volume MVR (unit: cm ^3/10 min) was measured.
The results are shown in Table 2.

After the obtained pellets of the permeate composition A to G were dried at 120 ° C. for 5 hours, the cylinder temperature was 255 ° C. and the mold temperature was 60 ° C. using an injection molding machine (NEX80-9E, manufactured by Nissei Resin Industry Co., Ltd.). Injection molding was performed at an injection speed of 73 mm / sec and an injection rate of 48 cm / sec to produce ^three types of molded products having a length of 60 mm × width of 60 mm, a thickness of 0.75 mm, 1 mm and 1.5 mm.
In addition, the actual temperature of the mold was measured at the time of manufacture. There are two measurement sites, the movable side and the fixed side of the mold, and the distance from the film gate 1 is 15 mm as shown in FIG. 1 in the molded product. When the mold surface temperature was measured with a contact type mold thermometer, it was confirmed that it was within the range of 60 ± 3 ° C.
From the obtained molded product, as shown in FIG. 1, from the positions where the distances from the film gate 1 are 10 mm, 25 mm, and 40 mm, the transmissive material 1 (site-1) to the transmissive material 3 (site-1) having a width of 10 mm and a length of 40 mm (site-1). Part-3) was cut out.
In addition, the same as above except that the injection speed was changed to 100 mm / sec and the injection rate was changed to 66 cm ³ / sec, from the positions where the distances from the film gate 1 were 10 mm, 25 mm and 40 mm, the transmissive material 1 (part-1) to The transparent material 3 (site-3) was cut out. Note that 4 in FIG. 1 indicates a laser irradiation location in the laser welding evaluation described later.

The transmittance (unit:%) at a wavelength of 940 nm was measured using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation) for the laser transmittance at the center of each transmitting material obtained above.
The results are shown in Table 2.

[Laser welding evaluation]
(Examples 1 to 15, Comparative Examples 1 to 13)
Among the transmissive materials shown in Table 2 obtained above, the transmissive material compositions and sites shown in Table 3 (thickness 1 mm) and Table 4 (thickness 1.5 mm) are 1 mm and 1.5 mm thick. The following laser welding test was performed with each transmission material of injection speed, injection rate, surface progress coefficient, and transmittance on the transmission side.
Using pellets obtained in the same manner as the above-mentioned transmission material except that the resin composition for a laser absorber having the following composition was used, the cylinder temperature was 255 ° C., the mold temperature was 60 ° C., the injection speed was 73 mm / sec, and the injection rate was 48 cm. Under the conditions of ³ / sec and a surface traveling coefficient of 480 cm / sec · cm ^, a molded product having the same length as the above-mentioned transmission material, 60 mm in length × 60 mm in width × 1 mm in thickness, was molded. From the obtained molded product, a portion 2 cut out in the same manner as the transmissive material was used as a laser absorbing member (absorbent material A).
Polybutylene terephthalate resin Novaduran (registered trademark, manufactured by Mitsubishi Engineering Plastics) 5008: 67.4% by mass
Glass fiber T-187 (manufactured by Nippon Electric Glass Co., Ltd.): 30% by mass
Stabilizer ADEKA SIZER EP-17 (manufactured by ADEKA): 0.4% by mass
Stabilizer ADEKA STAB AO-60 (manufactured by ADEKA): 0.2% by mass
Carbon black mass-batch (80% by mass of Novaduran 5008, 20% by mass of carbon black): 2% by mass

As shown in FIG. 2, the transmissive material and the absorbent material were overlapped and laser irradiation was performed. In FIG. 2, (a) shows a view of the transparent material and the absorbent material from the side, and (b) shows a view of the transparent material and the absorbent material from above. 2 is the laser transmitting material 1 to 3 (width 10 mm, length 40 mm, thickness 0.75 mm, 1 mm, and 1.5 mm), and 3 is the laser absorber (width 10 mm, length) which is a mating material to be welded. 40 mm, thickness 1 mm), and 4 indicates the laser irradiation location.
The transmissive material 2 and the absorbent material 3 were superposed as shown in FIG. 2, and laser light was irradiated from the transmissive material 2 side.

Laser welding uses a laser device manufactured by Fine Devices Co., Ltd. (laser 140W fiber core diameter 0.6mm), laser wavelength: 940nm, laser scan speed: 40mm / sec, scan length: 10mm, laser output: 20W (thickness 1mm). Alternatively, the procedure was performed at 50 W (thickness 1.5 mm), pressurization: 0.4 MPa, and distance between the laser head and the transmissive material 2: 79.7 mm.

The laser welding intensity of the welded welded material was measured. To measure the welding strength, a tensile tester ("5544 type" manufactured by Instron) is used, and the permeation material 2 and the absorbent material 3 that are welded and integrated are clamped at both ends in the long axis direction. , The evaluation was carried out by pulling at a tensile speed of 5 mm / min. The laser welding strength is shown by the tensile shear failure strength of the welded portion.
The results of the welding test are shown in Tables 3, 4 and 5 below.

(Examples 16 to 18)
Using pellets obtained in the same manner as the above-mentioned transmission material except that the resin composition for a laser absorber having the composition shown in Table 6 below was used, the cylinder temperature was 255 ° C., the mold temperature was 60 ° C., and the injection speed was 73 mm. Under the conditions of / sec, injection rate 48 cm ³ / sec, and surface advancement coefficient: 480 cm ³ / sec · cm, a molded product having the same length as the transmission material, 60 mm in length × 60 mm in width × 1 mm in thickness was molded. From the obtained molded product, a portion of the portion 2 was cut out in the same manner as the transmissive material, and used as a laser absorbing member (absorbent materials B to D).

The results of the welding test by laser welding with the transmission material (site-2) of the transmission material composition A are shown in Table 7 below in the same manner as in Example 1 except that the absorption materials B to D described above were used.

(Examples 19 to 21)
Each component listed in Table 8 below was used.

Among the components listed in Table 8 above, each component other than the polybutylene terephthalate resin, the nickel-containing colorant masterbatch and the glass fiber was previously blended (blended) in the amount (part by mass) shown in Table 9 below. Thing 1). Further, the polybutylene terephthalate resin and the nickel-containing colorant masterbatch were also blended in advance with a blender in the amounts (parts by mass) shown in Table 8 (blend product 2). The obtained blend 1 and blend 2 are supplied to the hopper from two independent feeders so as to have the ratio (part by mass) shown in Table 8, and this is supplied to the hopper with a 30 mm bent type 2 shaft. Using an extruder (manufactured by Japan Steel Works, "TEX30α"), glass fiber is supplied from the hopper from the 7th side feeder, and the extruder barrel set temperatures C1 to C15 are 270 ° C, the die is 260 ° C, and the discharge is 80 kg. It was melt-kneaded under the conditions of / hr, screw rotation speed 280 rpm, nozzle number 5 holes (circular (φ4 mm), length 1.5 cm), and shear rate (γ) 664 sec ^-1 , and extruded into a strand. The strand temperature immediately after extrusion was 275 ° C.
The extruded strands were introduced into a water tank whose temperature was adjusted to the temperature range of 40 to 80 ° C. and cooled. The strand surface temperature (T) is cooled to 110 ° C. at the temperature measured by an infrared thermometer (γ · T = 7.3 × 10 ⁴ ), inserted into a pelletizer and cut to form a polybutylene terephthalate resin composition. Pellets were obtained.

The characteristics of the obtained resin composition pellets were as follows: using an injection molding machine (J-85AD manufactured by Japan Steel Works, Ltd.), cylinder temperature 255 ° C., mold temperature 80 ° C., injection pressure 150 MPa, except for those specified. The following test pieces that were injection-molded under the conditions of an injection holding time of 15 sec, a cooling time of 15 sec, an injection speed of 65 mm / sec, a back pressure of 5 MPa, and a screw rotation speed of 100 rpm were evaluated. At the time of molding, the resin composition pellets were dried at 120 ° C. for 6 to 8 hours until just before that.

After the pellets of the resin composition obtained by the above method were dried at 120 ° C. for 6 hours, the cylinder temperature was 255 ° C. and the mold temperature was 60 ° C. in an injection molding machine (NEX80-9E, manufactured by Nissei Resin Industry Co., Ltd.). Injection molding was performed at 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 to produce a molded product having a length of 60 mm, a width of 60 mm, and a thickness of 0.75 mm.
From the obtained molded product, as shown in FIG. 1, a transmissive material having a width of 10 mm and a length of 40 mm was cut out from a position (site-3) having a distance of 40 mm from the film gate 1.

The following evaluations were made.
(1) Transmittance The laser transmittance at the center of the transmissive material obtained above was measured using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation) at a wavelength of 940 nm (unit:%). It was measured.
(2) Flame retardancy A UL94 test piece (125 mm × 12.5 mm × 3.0 mmt) is molded from the obtained resin composition pellets, and V-0, V-1, V are conformed to the UL94 standard. The judgment of -2 was made.
(3) Bending strength An ISO multipurpose test piece (4 mm thick) was formed from the obtained resin composition pellets, and the maximum bending strength (unit: MPa) was measured at a temperature of 23 ° C. in accordance with ISO178.

(4) Warpage The obtained resin composition pellets were stayed in a cylinder at a cylinder temperature of 250 ° C, a mold temperature of 80 ° C, and stayed in the cylinder for 20 minutes using a "model SE-50D" injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. , The rectangular parallelepiped box-shaped molded body shown in FIG. 4 was molded.
FIG. 4 is a perspective view of the box-shaped molded product used for evaluating the warpage property, and shows a state in which the bottom surface is turned up. The box-shaped molded body has a width of 25 mm, a length of 30 mm, a depth of 25 mm, a thickness of 1 mm on the bottom surface, and 0.5 mm for the others. The gate is a one-point gate (G in FIG. 4) in the center of the front side surface of the drawing.
It was fixed so that the bottom surface of the box was facing up, and the length L of the inward warp of the top of the inner surface when the inner surface of the drawing was inwardly warped in the inner direction of the box was measured (unit: mm).
The smaller this value is, the smaller the amount of inward warpage of the molded product is, which means that the dimensional accuracy is good.

(5) Long-diameter / short-diameter ratio of brominated polycarbonate-based flame retardant phase in the surface layer portion In the flow direction of the resin composition in the surface layer portion in the center of the transmission material obtained above (the surface layer portion having a cross-sectional depth of less than 20 μm). From the parallel cross section), an ultrathin section having a thickness of 300 nm was cut out using a “UC7” manufactured by Plastic Co., Ltd. with a diamond knife. The obtained ultrathin sections were stained with ruthenium tetroxide for 210 minutes, and then observed by SEM at an acceleration voltage of 1.5 to 2 kV using a scanning electron microscope "SU8020" manufactured by Hitachi High-Tech.
FIG. 3 shows a photograph of a backscattered electron image obtained by SEM / EDS analysis of the surface layer portion of the molded product obtained in Example 20.
The major axis and the minor axis of the brominated polycarbonate-based flame retardant phase were measured in 50 pieces of the brominated polycarbonate-based flame retardant phase and determined as the average value.

(6) Laser Welding Evaluation The following laser welding test was performed with the laser transmitting material obtained above on the transmitting side.
Using pellets obtained in the same manner as the above-mentioned transmission material except that the resin composition having the following composition was used, the cylinder temperature was 255 ° C., the mold temperature was 60 ° C., the injection speed was 100 mm / sec, and the injection rate was 66 cm ³ / sec. A molded product having a length of 60 mm, a width of 60 mm, and a thickness of 1 mm was molded under the condition of a surface advancing coefficient of 880 cm ³ / sec · cm. A material cut out from the obtained molded product in the same manner as the above-mentioned transmissive material was used as a laser absorbing member.
Polybutylene terephthalate resin Novaduran (registered trademark, manufactured by Mitsubishi Engineering Plastics) 5008: 67.4% by mass
Glass fiber T-187 (manufactured by Nippon Electric Glass Co., Ltd.): 30% by mass
Stabilizer ADEKA SIZER EP-17 (manufactured by ADEKA): 0.4% by mass
Stabilizer ADEKA STAB AO-60 (manufactured by ADEKA): 0.2% by mass
Carbon black mass-batch (80% by mass of Novaduran 5008, 20% by mass of carbon black): 2% by mass

The transmissive material 2 and the absorbent material 3 were superposed as shown in FIG. 2, and laser light was irradiated from the transmissive material 2 side.

Laser welding strength:
Laser welding uses a laser device manufactured by Fine Devices Co., Ltd. (laser 140W fiber core diameter 0.6mm), laser wavelength: 940nm, laser scan speed: 40mm / sec, scan length: 10mm, laser output: 20W, pressurization: 0. The measurement was performed at 0.4 MPa, the distance between the laser head and the transmissive material 2: 79.7 mm.
Laser welding strength was measured using a welded body that was welded and integrated. To measure the welding strength, a tensile tester ("5544 type" manufactured by Instron) is used, and the permeation material 2 and the absorbent material 3 that are welded and integrated are clamped at both ends in the long axis direction. , The evaluation was carried out by pulling at a tensile speed of 5 mm / min. The laser welding strength is shown by the tensile shear breaking strength (unit: N) of the welded portion.

Laser welding processability:
The laser welding test was performed by variously changing the laser scanning speed every 5 mm / sec under the same conditions as the above laser welding intensity measurement except for the laser scanning speed. The fastest scanning speed that can achieve a laser welding intensity of 100 N or more was obtained and used as an index of laser welding processability. It can be said that the faster the scanning speed, the shorter the laser welding time and the better the laser welding processability.
The above results are shown in Table 9 below.

The laser welding member of the present invention has extremely excellent laser transmission and laser welding processability, and a molded product obtained by laser welding thereof has excellent welding strength. It can be suitably used for equipment parts, industrial machine parts, and other consumer parts.

1: Film gate 2: Laser absorber 2
3: Laser transmissive material 3
4: Laser irradiation location

Claims (6)

A first laser welding member made by injection molding a thermoplastic polyester resin material and a second member made of a resin material having laser absorption are irradiated with laser light from the first laser welding member side. It is a method of manufacturing a laser welded molded product that is laser welded.
The thermoplastic polyester resin material for the first laser welding member contains a polybutylene terephthalate resin , a polycarbonate resin and an organic phosphate phosphate , and the content of the polycarbonate resin is 100 in total of the polybutylene terephthalate resin and the polycarbonate resin. It is 10 to 50% by mass with respect to mass%, and the content of the organic phosphate phosphate compound is 0.001 to 1 part by mass with respect to 100 parts by mass of the thermoplastic polyester resin and other resins.
The resin material of the second member is a thermoplastic polyester-based resin composition, which contains carbon black or a laser light-absorbing dye.
The laser-welded portion of the first member is located at a position separated from the gate of the injection molding mold by 15 mm or more, has a light transmittance of 40% or more in laser light having a wavelength of 940 nm, and is said to be the same. A method for producing a laser welded molded product, characterized in that the crystallization temperature of the site is 188 ° C. or lower. The method for producing a laser welded molded product according to claim 1, wherein the thermoplastic polyester resin composition of the second member is a polybutylene terephthalate resin in an amount of 50% by mass or more in the polyester resin. The method for producing a laser-welded laser-welded molded product according to claim 1 or 2 , wherein the resin material forming the first member and the second member further contains glass fiber. One of claims 1 to 3 , wherein the laser welding member is a member obtained by injection molding the thermoplastic polyester resin material under the conditions of an injection rate of 10 to 300 cm ³ / sec as defined below. A method for manufacturing a laser welded molded product according to.
Injection rate: Resin material capacity per unit time ejected from the ejection nozzle of the injection molding machine into the mold cavity Any of claims 1 to 4 , wherein the laser welding member is a member obtained by injection molding the thermoplastic polyester resin material under the conditions of a surface traveling coefficient of 100 to 1200 cm ³ / sec · cm defined below. The method for manufacturing a laser welded molded product according to item 1.
Surface progress coefficient: A value obtained by dividing the injection rate by the thickness of the mold cavity into which the resin material is injected. The laser welded molded product according to any one of claims 1 to 5 , wherein the melt volume rate (measured at 250 ° C. and a load of 5 kg) of the thermoplastic polyester resin material is 10 cm ^3/10 minutes or more. Production method.

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