JP6683482B2 - Laser welding members and molded products - Google Patents

Description

  TECHNICAL FIELD 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 viewpoint of weight reduction and recycling and other environmental aspects, parts that have been conventionally made of metal have been made into resin, and resin products have become smaller. Thermoplastic polyester resins have excellent mechanical strength, chemical resistance, electrical insulation, etc., and also have excellent heat resistance, moldability, and recyclability, so they are widely used in various equipment parts. ing. In particular, thermoplastic polyester resins such as polybutylene terephthalate resin have excellent mechanical strength and moldability, and because they are flame-retardant, they are widely used in electric and electronic parts that require fire safety. There is.
In addition, recently, in order to manufacture these equipment parts, the number of cases where parts are joined by welding processing for increasing productivity efficiency is increasing, and in particular, laser welding, which has little influence on electronic parts, is often used. There is.

  However, compared with polycarbonate resins and polystyrene resins, thermoplastic polyester resins, especially polybutylene terephthalate resins, have poor laser welding processability due to their low laser transparency, and their welding strength tends to be insufficient. As a result, it is rather unsuitable.

In order to improve the laser weldability of polybutylene terephthalate resin, a method of using copolymerized polybutylene terephthalate (Patent Document 1) has been proposed. However, in this method, sufficient weldability may not be obtained due to a gap between welding members caused by warp deformation of a molded product. Further, a method (patent document 2) of adding a laser transmission absorber such as nigrosine to a thermoplastic resin to improve the weldability has also been proposed.
In particular, flame-retarded polybutylene terephthalate resin has low laser transparency, and laser welding is often difficult. Patent Document 3 proposes a method in which phosphinic acids are added to a polybutylene terephthalate resin to achieve both laser transparency and flame retardancy, but the laser transparency is low, and the influence of warpage of the molded product, etc. Therefore, in many cases, sufficient welding strength could not be obtained.

Japanese Patent No. 3510817 JP, 2008-1112, A International publication WO2007-77794

  As described above, various problems are likely to be involved in an attempt to improve the laser welding processability by blending a thermoplastic polyester resin such as a polybutylene terephthalate resin with other components. A welding member for laser welding is often manufactured by injection molding, and is molded by injecting a resin in a fluid state from a gate provided in a cavity of a molding die. In particular, in recent years, the weight reduction and thinning of parts are rapidly progressing, and the characteristics and performances of the molded products tend to vary depending on the parts.

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

The present inventor, in a welding member injection-molded of a thermoplastic polyester resin, as a result of repeated examinations of individual portions thereof, a specific portion of a molded article was used as a welding portion for laser welding, and thus an excellent laser was obtained. They have found that they can exhibit transparency and laser welding processability, and have reached the present invention.
The present invention relates to the following laser welding member, molded article, and laser welding method.

[1] A laser welding member formed by injection-molding a thermoplastic polyester resin material,
The portion of the member to be laser-welded is located at a position 15 mm or more away from the gate of the injection molding die, and has a light transmittance of 30% or more in a laser beam having a wavelength of 940 nm. Parts.
[2] The laser welding member according to the above [1], which is obtained by injection-molding a thermoplastic polyester resin material under the condition of an injection rate defined below of 10 to 300 cm ³ / sec.
Injection rate: Volume of resin material per unit time injected from a discharge nozzle of an injection molding machine into a mold cavity [3] A thermoplastic polyester under the condition of a surface progression coefficient of 100 to 1200 cm ³ / sec · cm defined below. The laser welding member according to the above [1] or [2], which is obtained by injection-molding a resin material.
Surface Progression Coefficient: A value obtained by dividing the above 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 under the conditions of 250 ° C. and a load of 5 kg) 10 cm ^3/10 minutes or more at which the above-mentioned [1] laser welding member according to any one of - [3].

[5] The laser welding member according to any one of [1] to [4] above, 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 mass with respect to 100 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 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 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 mass% with respect to 100 mass% of the total 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 butadiene rubber-containing polystyrene and a polycarbonate resin, and a total of 100 polybutylene terephthalate resin, polystyrene and / or butadiene rubber-containing polystyrene and a polycarbonate resin. In the above [1] to [4], the polybutylene terephthalate resin is contained in an amount of 30 to 90% by mass, the polystyrene and / or the butadiene rubber-containing polystyrene is included in an amount of 1 to 50% by mass, and the polycarbonate resin is included in an amount of 1 to 50% by mass. The member for laser welding according to any one of claims.

[10] The laser welding member according to any one of the above [1] to [9], which is used as a 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 absorbability are provided on the first laser welding member side. Molded product that is laser-welded by irradiating laser light from the.
[12] A first laser welding member formed by injection-molding a thermoplastic polyester-based resin material and a second member formed of a resin material having laser absorbability are provided with a laser from the first laser welding member side. A method for producing a laser-welded molded article, which comprises irradiating light to perform laser welding,
The portion of the first member to be laser-welded is located at a position 15 mm or more away from the gate of the injection molding die, and has a light transmittance of 30% or more in a laser beam having a wavelength of 940 nm. A method for producing a laser-welded molded article.

  The laser-welding member obtained by injection-molding the thermoplastic polyester-based resin material of the present invention has a high laser transmittance in the welded portion, excellent laser welding processability, and a welded body obtained by laser-welding this welding member is Excellent in welding strength.

It is a top view which shows the position on the injection molded article of the permeable materials 1-3 used in the Example. It is the schematic which shows the laser welding strength measuring method in an Example. (A) shows a side view of the laser absorbing material and the transmitting material, and (b) shows a top view thereof. 20 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. It is a perspective view of the box-shaped molded object used for evaluation of the warpability 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 portion of the member to be laser-welded is located at a position 15 mm or more away from the gate of the injection molding die, and has a light transmittance of 30% or more for laser light having a wavelength of 940 nm.

  Hereinafter, the content of the present invention will be described in detail. The following description may be given based on the representative embodiments and specific examples of the present invention, but the present invention should not be construed as being limited to such embodiments and specific 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 or polycondensation of these compounds, and may be either a homopolyester or a copolyester. .

As the dicarboxylic acid compound constituting the thermoplastic polyester resin, aromatic dicarboxylic acid or its ester-forming derivative 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, Biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid , Diphenylisopropylidene-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, Refutaru acid can be preferably used.

Two or more kinds of these aromatic dicarboxylic acids may be mixed and used. As well known, these can be used in the polycondensation reaction as an ester-forming derivative such as dimethyl ester in addition to the free acid.
If the amount is small, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, and sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1 are used together with these aromatic dicarboxylic acids. One or more alicyclic dicarboxylic acids such as 4,4-cyclohexanedicarboxylic acid 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. , Alicyclic diols such as cyclohexane-1,4-dimethanol, and the like, 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 and the like may be copolymerized.
Further, 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 bifunctional monomers, trimellitic acid for introducing a branched structure, trimesic acid, pyromellitic acid, pentaerythritol, trifunctional monomers such as trimethylolpropane, and fatty acid for molecular weight adjustment A small amount of monofunctional compound can be used together.

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

  Among 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 thereof are polybutylene terephthalate and polyethylene terephthalate. It is preferable that these are close to homopolyesters, that is, 95% by mass or more of the entire 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 moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.5 to 1.5 dl / g are more preferable. When an intrinsic viscosity of less than 0.3 dl / g is used, the resulting resin composition tends to have low mechanical strength. On the other hand, if it is higher than 2 dl / g, the fluidity of the resin composition may be deteriorated, the moldability may be deteriorated, and the laser weldability may be deteriorated.
The intrinsic viscosity of the thermoplastic polyester resin is a value measured at 30 ° C. in a mixed solvent of 1: 1 (mass ratio) of tetrachloroethane and phenol.

  The amount of terminal carboxyl groups 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. . When it exceeds 50 eq / ton, gas is likely to be generated during melt molding of the resin composition. The lower limit of the amount of terminal carboxyl group is not particularly limited, but is usually 10 eq / ton.

  The amount of terminal carboxyl groups of 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 it with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. As a method for adjusting the amount of terminal carboxyl groups, a raw material charging ratio during polymerization, a method for adjusting polymerization conditions such as a polymerization temperature and a depressurizing method, a method for reacting an end capping agent, and the like can be performed by any conventionally known method. I'll do it.

  Above all, 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 a polybutylene terephthalate resin.

  The polybutylene terephthalate resin is produced by melt-polymerizing a dicarboxylic acid component having terephthalic acid as a main component or an ester derivative thereof and a diol component having 1,4-butanediol as a main component in a batch system or a continuous system. can do. In addition, the degree of polymerization (or molecular weight) can be increased to a desired value by producing a low molecular weight polybutylene terephthalate resin by melt polymerization and then further performing solid phase polymerization under a nitrogen stream or under reduced pressure.

  The polybutylene terephthalate resin is preferably produced by a continuous method of melt polycondensation 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 for carrying out the esterification reaction may be a conventionally known catalyst, and examples thereof include a titanium compound, a tin compound, a magnesium compound and a calcium compound. Particularly preferable among these are titanium compounds. Specific examples of the titanium compound as the 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, also referred to as “modified polybutylene terephthalate resin”), but a specific preferable copolymer thereof is Examples thereof include a polyester ether resin copolymerized with alkylene glycols (particularly polytetramethylene glycol), a dimer acid copolymerized polybutylene terephthalate resin, and an isophthalic acid copolymerized polybutylene terephthalate resin.

When a polyester ether resin obtained by copolymerizing 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, and 5 to 30% by mass. % Is more preferable, and 10 to 25% by mass is further preferable. By setting such a copolymerization ratio, the balance between laser weldability and heat resistance tends to be excellent, which is preferable.
When a dimer acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the proportion of the dimer acid component in the total carboxylic acid component is preferably 0.5 to 30 mol% as a carboxylic acid group, 1 to 20 mol% is more preferable, and 3 to 15 mol% is further preferable. By setting such a copolymerization ratio, the laser weldability, long-term heat resistance and toughness tend to be excellent, which is preferable.
When an isophthalic acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the proportion of the isophthalic acid component in 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 further preferable. Such a copolymerization ratio is preferable because it tends to have an excellent balance of laser weldability, heat resistance, injection moldability, and toughness.
Among the modified polybutylene terephthalate resins, a polyester ether resin copolymerized with polytetramethylene glycol and an isophthalic acid copolymerized polybutylene terephthalate resin are preferable.

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

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

  The amount of terminal carboxyl groups 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. . When it exceeds 50 eq / ton, gas is likely to be generated during melt molding of the resin composition. The lower limit of the amount of terminal carboxyl groups is not particularly limited, but is usually 10 eq / ton in consideration of the productivity in producing the polybutylene terephthalate resin.

  The amount of the terminal carboxyl groups of the polybutylene terephthalate resin is a value measured by dissolving 0.5 g of the polyalkylene terephthalate resin in 25 mL of benzyl alcohol and titrating with a 0.01 mol / l benzyl alcohol solution of sodium hydroxide. is there. As a method for adjusting the amount of terminal carboxyl groups, a raw material charging ratio during polymerization, a method for adjusting polymerization conditions such as a polymerization temperature and a depressurizing method, a method for reacting an end capping agent, and the like can be performed by any conventionally known method. I'll do it.

As the thermoplastic polyester resin, a resin containing a polybutylene terephthalate resin and the modified polybutylene terephthalate resin is also preferable. It is preferable that the modified polybutylene 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 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 further preferably 30 to 60% by mass. When the content of the modified polybutylene terephthalate resin is less than 10% by mass, the laser welding strength tends to decrease, and when it exceeds 70% by mass, the moldability may significantly decrease, which is not preferable.

Further, the thermoplastic polyester resin preferably contains a polybutylene terephthalate resin and a polyethylene terephthalate resin. By containing a specific amount of polyethylene terephthalate resin, laser transmittance and laser weldability are easily improved, which is preferable.
When the polybutylene terephthalate resin and the polyethylene terephthalate resin are contained, the content of the polyethylene terephthalate resin is preferably 5 to 50 mass% with respect to the total 100 mass% of the polybutylene terephthalate resin and the polyethylene terephthalate resin. It is more preferably 10 to 45% by mass, and further 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 decreased, which is not preferable.

  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 includes constituent repeating units other than oxyethylene oxyterephthaloyl units. Good. The polyethylene terephthalate resin is produced by using terephthalic acid or its lower alkyl ester and ethylene glycol as main raw materials, but other acid components and / or other glycol components may be used as raw materials in combination.

  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 diol components other than ethylene glycol include 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol and other aliphatic glycols, cyclohexane. Examples thereof include alicyclic glycols such as dimethanol and aromatic dihydroxy compound derivatives such as bisphenol A and bisphenol S.

  Further, the polyethylene terephthalate resin is a branched component, for example, trifunctional acid such as tricarballylic acid, trimellitic acid, trimellitic acid, or tetrafunctional acid such as pyromellitic acid, or glycerin, trimethylolpropane, pentapentic acid having performance. It is obtained by copolymerizing 1.0 mol% or less, preferably 0.5 mol% or less, more preferably 0.3 mol% or less of an alcohol having a trifunctional or tetrafunctional ester forming ability such as erythritol. It may be.

The intrinsic 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 mixed solvent of 1: 1 (mass ratio) of tetrachloroethane and phenol.

The concentration of the terminal carboxyl group of the polyethylene terephthalate resin is preferably 3 to 50 eq / ton, particularly 5 to 40 eq / ton, and more preferably 10 to 30 eq / ton. When the terminal carboxyl group concentration is 50 eq / ton or less, gas is less likely to be generated during melt molding of the resin composition, and mechanical properties of the obtained laser welding member tend to be improved. When the concentration is 3 eq / ton or more, the heat resistance, residence heat stability and hue of the laser welding member tend to be improved, which is preferable.
The terminal carboxyl group concentration of the polyethylene terephthalate resin is a value determined by dissolving 0.5 g of the polyethylene terephthalate resin in 25 mL of benzyl alcohol and titrating the solution with 0.01 mol / L benzyl alcohol solution of sodium hydroxide. is there.
As a method for adjusting the amount of terminal carboxyl groups, a raw material charging ratio during polymerization, a method for adjusting polymerization conditions such as a polymerization temperature and a depressurizing method, a method for reacting an end capping agent, and the like can be performed by any conventionally known method. I'll 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, the thermoplastic polyester resin material has a melt volume rate (MVR;. 250 ℃, measured under the conditions of a load 5 kg) is preferably at least 10 cm ^3/10 min, more preferably 15cm ^3/10 Use one that is more than a minute. 280 ° C., when measured under a load of 2.16kg is preferably 20 cm ^3/10 minutes or more, more preferably used as it is 30 cm ^3/10 minutes or more. By using the MVR having such a range, good molding can be achieved even if the welding member has a thin portion of 2 mm or less, or 1.5 mm or less, and an extremely thin thin portion of 1 mm or less. You can secure the sex.

  Further, the crystallization temperature (Tc) of the thermoplastic polyester resin material is preferably 190 ° C. or lower. That is, the laser transparency can be further improved by controlling the crystallization temperature (Tc) to be low. The crystallization temperature (Tc) is preferably 188 ° C or lower, more preferably 185 ° C or lower, further 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) was measured by DSC, and the details are as described in the 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 or an injection compression molding method 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, particularly 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, it is preferable that the injection rate is defined as a resin material capacity per unit is injection time from the discharge nozzle to the mold cavity of the injection molding machine is ^{10~300cm 3 / sec, 15~200cm 3 /} sec Gayori It is preferably from 25 to 100 cm ³ / sec, more preferably from 50 to 90 cm ³ / sec. By setting the emission rate in such a range, it becomes easier to increase the laser transmittance of the portion on the side opposite to the gate of the member, and the transmittance of the welded portion in the member can be increased by adjusting the gate position. . In injection molding, the volume of resin material injected per unit time is controlled by adjusting the injection volume of resin material per unit time and the time required for injection, but the material volume of resin material per unit time is injected. Rate (unit: cm ³ / sec).

In addition, it is preferable to perform injection molding under the condition that the surface progression coefficient defined below is 100 to 1200 cm ³ / sec · cm. By setting the surface progression coefficient in such a range, it becomes easier to increase the laser transmittance of the portion opposite to the gate side of the member, and it is possible to increase the transmittance of the welded portion in the member by adjusting the gate position. it can.
Surface Progression Coefficient: A value obtained by dividing the injection rate by the thickness of the mold cavity into which the resin material is injected. The range of the preferred surface progression 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 above thermoplastic polyester resin material is subjected to laser welding. The method of laser welding is not particularly limited, and a usual method can be used. The molded body (first member) obtained by injection molding a thermoplastic polyester resin material is made to be the transmission side, and the resin molded body of the mating material (second member, adherend) is brought into contact (especially at least welding). Parts are brought into surface contact with each other and irradiated with a laser beam to weld and integrate the two kinds of molded products into one molded product. The present invention is characterized in that laser welding is performed at a portion at a distance of 15 mm or more from the gate of the injection mold as a welding portion. It is necessary that at least a part of the laser welded portion 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 portion is separated by 15 mm or more from the gate, and 50% or more is more preferable. 70% or more is more preferable, and it is particularly preferable that all the portions to be laser-welded are separated from the gate by 15 mm or more.

When the thermoplastic polyester resin material of the present invention is injection-molded, the laser transmittance varies greatly depending on the site (position) of the molded product, the transmittance is poor at the site close to the gate position, and the distance from the gate becomes long. It has been clarified by the present inventors that excellent transmittance is exhibited. For example, as will be shown in Examples described later, 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 is improved as the distance is increased. The degree of improvement in transmittance depends on the composition of the thermoplastic polyester-based resin material used, the thickness of the laser-welded portion, the injection molding conditions, and the like, but those with high transmittance (for example, transmitting material composition A to It has been found that extremely high transmittances such as D of 50% to 60%, 70%, and 80% can be achieved with D, especially with the transmission material compositions A and B.
Further, the transmittance is affected by the composition of the thermoplastic polyester resin material used, the thickness of the laser welding portion, the injection molding conditions, etc., but in the present invention, the composition of the thermoplastic polyester resin material, the laser welding portion Regardless of the thickness, injection molding conditions, etc., laser processability is improved and firm laser welding is possible by setting the light transmittance of the laser beam at the laser beam of 940 nm at the laser welding site to 30% or more. Becomes

  The shape of the laser welding member is not limited, and the distance from the gate of the injection mold is 15 mm or more, preferably 20 mm or more, more preferably 25 mm or more, further preferably 30 mm or more, particularly preferably 35 mm or more, most preferably May have any shape as long as it has a welding portion at a position separated by 40 mm or more. Usually, the welded portion is joined to the mating material (other resin or a molded body of the same resin) and laser welded, so that the welded portion has a shape (for example, a plate shape) having at least a contact surface (a flat surface or the like). . The thickness of the laser welding part (the part to be irradiated with laser) can be selected from a wide range, and is 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 object can be regarded as a planar shape and can be arbitrarily set within a 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, further 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, and a multi-point gate system may be used. The number of resin gates of the mold at the time of molding with respect to the surface area of the welding member is preferably 4 pieces / cm ² or less, more preferably 3 pieces / cm ² or less, and 2 pieces / cm ² or less. Is more preferable.

The laser welding site preferably has a light transmittance of 35% or more for laser light having a wavelength of 940 nm, more preferably 40% or more, more preferably 45% or more, and further 50% or more, among others. It is preferably 55% or more, particularly 60% or more, particularly preferably 65% or more, and most preferably 70% or more.
Since the transmittance increases as the thickness of the molded product decreases, the composition of the thermoplastic polyester resin material used, the thickness of the molded product, the distance from the gate of the injection molding die, and the injection rate are set in order to achieve the above-mentioned preferred transmittance. Molding conditions such as speed, injection rate, surface progress coefficient, resin temperature and mold temperature may be appropriately adjusted so that the laser welding site has a higher transmittance.
In addition, the transmittance in the present invention refers to the transmittance of laser light having a wavelength of 940 nm.

  The crystallization temperature (Tc) of the portion to be laser-welded is preferably 190 ° C. or lower, more preferably 188 ° C. or lower, further preferably 185 ° C. or lower, particularly preferably 182 ° C. or lower, 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 of the thermoplastic polyester resin material and the other member containing the laser light absorber are brought into surface contact or butt contact, and usually the above-mentioned welding having high transmittance is performed. By irradiating a laser beam from the member side, the interface between the two is at least partially melted and cooled to be integrated into one molded article.

  The partner member containing the laser light absorber is not particularly limited as long as it is a member that can absorb laser light and is melted by absorbing the laser light. . Specific examples include a member usually made of a resin composition containing carbon black or a laser-absorbing dye in order to be able to absorb laser light. The content of the absorbent such as carbon black is not particularly limited, but it is preferably contained in the resin composition in an amount of 0.2 to 1% by mass.

Preferred examples of the laser light absorbing dye include nigrosine, aniline black, phthalocyanine, naphthalocyanine, porphyrin, perylene, quaterrylene, azo dye, anthraquinone, squaric acid derivative and immonium.
Of these, nigrosine is particularly preferred. Nigrosine is a C.I. I. SOLVENT BLACK 5 and C.I. I. A black azine-based condensation mixture as described in COLOR INDEX as SOLVENT BLACK 7. Examples of commercially available products of nigrosine 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, with respect to 100 parts by mass of the resin component. 0.05 parts by mass.

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

  The type of laser light to be irradiated is arbitrary as long as it is a 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. Particularly, 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 application of the welded body is electrical parts for transportation equipment such as automobiles, electric and electronic equipment parts, industrial machine parts, etc. It is particularly suitable for consumer parts and the like.

As described above, the thermoplastic polyester resin material used in the present invention may contain other resins or additives.
As other resins, various thermoplastic resins can be contained, and examples thereof include polystyrene, butadiene rubber-containing polystyrene, aromatic vinyl resins such as acrylonitrile-styrene copolymer, and polycarbonate resins. In the present invention, 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 in order to achieve high laser transmittance.

[Polycarbonate resin]
It is also preferable that the thermoplastic polyester resin material contains a thermoplastic polyester resin and a polycarbonate resin. It is preferable that the polycarbonate resin is contained in a specific amount because the laser weldability is easily improved.
Polycarbonate resins are optionally branched thermoplastic polymers or copolymers obtained by reacting a dihydroxy compound or a small amount thereof with a polyhydroxy compound with phosgene or a carbonic acid diester. The production method of the polycarbonate resin is not particularly limited, and those produced by a conventionally known phosgene method (interfacial polymerization method) or a melting method (transesterification method) can be used. It is preferable in terms of laser transparency 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, and 4,4-dihydroxydiphenyl, and bisphenol A is preferable. It is also possible to use a compound in which one or more tetraalkylphosphonium sulfonates are bound to the above aromatic dihydroxy compound.

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

  To control the molecular weight of the polycarbonate resin, a monovalent aromatic hydroxy compound may be used, and examples thereof include m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, and 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 more preferably 14,000 to 24,000. If the viscosity average molecular weight is lower than 5,000, the resulting welding member tends to have low mechanical strength. On the other hand, if it is higher than 30,000, the fluidity of the resin material may be deteriorated, the moldability may be deteriorated, and the laser weldability may be deteriorated. The viscosity average molecular weight of the polycarbonate resin is a viscosity average molecular weight [Mv] calculated 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 weight average molecular weight Mw and the number average molecular weight Mn of the polycarbonate resin measured by gel permeation chromatography (GPC) is preferably 2 to 5, and 2.5 -4 are 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 increases, and molding tends to be difficult.

  Further, the amount of terminal hydroxy groups of the polycarbonate resin is preferably 100 mass ppm or more, more preferably 200 mass ppm or more, and further preferably 400 mass ppm from the viewpoints of thermal stability, hydrolysis stability, color tone and the like. As described above, the most preferable content is 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 of the polycarbonate resin is excessively small, the laser transmittance tends to decrease, and the initial hue during molding may deteriorate. If the amount of terminal hydroxy groups is too large, the retention heat stability and the moist heat resistance tend to decrease.

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

In the melt polymerization method, transesterification reaction between an aromatic dihydroxy compound and a carbonic acid diester is carried out.
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; diaryl carbonates such as substituted diphenyl carbonate such as ditolyl carbonate. Among them, diaryl carbonate is preferable, and diphenyl carbonate is particularly preferable. One kind of carbonic acid diester may be used, or two or more kinds thereof may be used in optional combination and ratio.

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

  In a polycarbonate resin, the amount of terminal hydroxy groups tends to have a great influence on heat stability, hydrolysis stability, color tone and the like. Therefore, the amount of terminal hydroxy groups may be adjusted as necessary by any known method. In the transesterification reaction, usually, 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, a polycarbonate resin having an adjusted amount of terminal hydroxy groups can be obtained. By this operation, the molecular weight of the polycarbonate resin usually obtained 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 terminal hydroxy groups, the mixing ratio is as described above.
Further, as a more positive adjustment method, a method of separately mixing a terminal stopper at the time of reaction can be mentioned. Examples of the terminal terminator at this time include monohydric phenols, monohydric carboxylic acids, and carbonic acid diesters. In addition, 1 type may be used for a terminal terminator and 2 or more types may be used together by arbitrary combinations and ratios.

  When producing a polycarbonate resin by the melt polymerization method, an ester exchange 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. In addition, 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 an auxiliary. The transesterification catalyst may be used alone or in any combination of two or more at any 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 the conditions of this range while removing by-products such as hydroxy compounds.

  The melt polycondensation reaction can be performed by either a batch method or a continuous method. When the reaction is carried out in a batch system, the order of mixing the reaction substrate, the reaction medium, the catalyst, the additives and the like is arbitrary as long as the desired polycarbonate resin can be obtained, and an appropriate order may be set arbitrarily. However, in consideration of 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 deactivator may be used if necessary. As the catalyst deactivator, any compound that neutralizes the transesterification catalyst can be used. Examples thereof include sulfur-containing acidic compounds and their derivatives. The catalyst deactivator may be used alone or in any combination of two or more at any ratio.
The amount of the catalyst deactivator to be 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 transesterification catalyst. It is preferably 5 equivalents or less. Further, it is usually 1 mass ppm or more, and usually 100 mass ppm or less, and preferably 20 mass ppm or less with respect to the polycarbonate resin.

  When the thermoplastic polyester resin material contains a thermoplastic polyester resin and a polycarbonate resin, the content of the polycarbonate resin is preferably 10 to 50 with respect to 100% by mass of the total amount of the thermoplastic polyester resin and the polycarbonate resin. %, More preferably 15 to 45% by mass, further preferably 20 to 40% by mass. When the content of the polycarbonate resin is less than 10% by mass, the laser welding strength tends to decrease, and when it exceeds 50% by mass, the moldability may be significantly decreased, which is not preferable.

[Aromatic vinyl resin]
It is also preferable that the thermoplastic polyester-based resin material contains a thermoplastic polyester resin and an aromatic vinyl-based resin.
The aromatic vinyl 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 and vinylxylene. , And preferably styrene. Polystyrene (PS) is a typical aromatic vinyl resin.
Further, as the aromatic vinyl 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 hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene. In the present invention, butadiene rubber is preferably used. Although an acrylic rubber component can be used as the rubber component, it is not preferable because it becomes 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 segments of the aromatic vinyl resin. 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 particularly preferable from the viewpoint of toughness.

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

The aromatic vinyl resin preferably has a melt flow rate (MFR) measured at 200 ° C. and 98 N of 0.1 to 50 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes. It is 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 occur during injection molding. If the MFR is more than 50 g / 10 minutes, the impact resistance is greatly reduced, which is not preferable.
Particularly, in the case of polystyrene, the MFR is preferably 1 to 50 g / 10 minutes, more preferably 3 to 35 g / 10 minutes, and further preferably 5 to 20 g / 10 minutes. In the case of the butadiene rubber-containing polystyrene, the MFR is preferably 0.1 to 40 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes, and even more preferably 1 to 20 g / 10 minutes. More preferable.

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

In particular, in the present invention, it is preferable that the thermoplastic polyester-based resin material contains a thermoplastic polyester resin, polystyrene and / or polystyrene containing butadiene rubber, and a polycarbonate resin from the viewpoint of laser welding.
The polycarbonate resin is as described above.
The polystyrene is a homopolymer of styrene or a copolymer of other aromatic vinyl monomers such as α-methylstyrene, paramethylstyrene, vinyltoluene, and vinylxylene in a range of 50% by mass or less. May be.

The butadiene rubber-containing polystyrene 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, It is preferably 5 to 30% by mass, and more preferably 5 to 20% by mass. High impact polystyrene (HIPS) is particularly preferable as the butadiene rubber-containing polystyrene.
Among polystyrene or polystyrene containing butadiene rubber, polystyrene containing butadiene rubber is preferable, and high impact polystyrene (HIPS) is particularly preferable.

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

When the thermoplastic polyester-based resin material contains the thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and polycarbonate resin, the crystallization temperature (Tc) of the obtained thermoplastic polyester-based resin material is 190 ° C. or lower. Is preferred. That is, by appropriately suppressing the transesterification reaction between the thermoplastic polyester resin and the polycarbonate resin and appropriately lowering the crystallization temperature, the laser transmittance can be further improved. The crystallization temperature (Tc) is more preferably 188 ° C or lower, further 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 a thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene, and a polycarbonate resin, the content is as follows.
The content of the thermoplastic polyester resin is preferably 30 to 90% by mass, and 40 to 80% by mass based on the total 100% by mass of the thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and polycarbonate resin. More preferably, 50-70 mass% is still more 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 butadiene rubber-containing polystyrene is preferably 1 to 50% by mass based on the total 100% by mass of the thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and polycarbonate resin. 45 mass% is more preferable, and 5-40 mass% is still more 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 greatly reduced, which is not preferable.

  The content of the polycarbonate resin is preferably 1 to 50% by mass, and more preferably 3 to 45% by mass, based on the total 100% by mass of the thermoplastic polyester resin, polystyrene and / or butadiene rubber-containing polystyrene and the polycarbonate resin. , 5 to 40 mass% is more preferable. If the content is less than 1% by mass, the laser weldability is lowered and the polystyrene and / or butadiene rubber-containing polystyrene is poorly dispersed, so that the surface appearance of the molded article is apt to be lowered. If it exceeds 50% by mass, transesterification with the thermoplastic polyester resin may proceed, and the residence heat stability may be lowered, which is not preferable.

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

  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 components]
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, reinforcing fillers, flame retardants, flame retardant aids, anti-dripping agents, UV absorbers, antistatic agents, anti-fog agents, lubricants, anti-blocking agents, plasticizers. Agents, dispersants, antibacterial agents and the like.

The thermoplastic polyester resin material used in the present invention preferably also contains a flame retardant. There are various flame retardants such as halogen-based flame retardants, phosphorus-based flame retardants (melamine polyphosphate, etc.), nitrogen-based flame retardants (melamine cyanurate, etc.), metal hydroxides (magnesium hydroxide, etc.), In the present invention, the halogen-based flame retardant is preferably a brominated flame retardant, more preferably a brominated polycarbonate, a brominated epoxy compound, a brominated poly (meth) acrylate, etc., and particularly contains a brominated polycarbonate flame retardant. It is preferable. Generally, it is common that the transmittance decreases when a halogen-based flame retardant is contained, but by containing a brominated polycarbonate-based flame retardant in combination with a nickel-containing coloring agent described below, good flame retardancy and laser The light transmittance is compatible with each other, and the obtained molded product 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 flame retardant phase is dispersed in the surface layer portion of the obtained molded article without stretching as much as other flame retardants. It is considered that the transmittance is high because the ratio of the major axis to the minor axis of the brominated polycarbonate flame retardant phase in the surface layer is small and the internal scattering of laser light is small.

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

  The average number of carbonate repeating units in the brominated polycarbonate flame retardant may be appropriately selected and determined, but is usually 2 to 30. When the average number of carbonate repeating units is small, the molecular weight of the thermoplastic polyester resin may decrease when melted. On the other hand, if it is too large, it may cause poor dispersion in the molded body, and the appearance of the molded body, particularly the glossiness, may deteriorate. Therefore, the average number of repeating units is preferably 3 to 15, and particularly preferably 3 to 10.

The molecular weight of the brominated polycarbonate 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, among others. It is preferably 1,500 to 10,000.
The viscosity average molecular weight of the brominated polycarbonate flame retardant was determined by measuring the intrinsic viscosity ([η]) of the methylene chloride solution of the brominated polycarbonate resin using an Ubbelohde viscometer at 20 ° C. The value calculated from the Schnell's viscosity formula of is shown.
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

  The brominated polycarbonate flame retardant obtained from the brominated bisphenol A can be obtained, for example, by a usual method of reacting brominated bisphenol with phosgene. The end-capping agent includes an aromatic monohydroxy compound, which may be substituted with halogen or an organic group.

  The content of the brominated polycarbonate flame retardant is preferably 20 to 70 parts by mass, more preferably 25 parts by mass or more, further preferably 30 parts by mass or more, and especially 100 parts by mass of the thermoplastic polyester resin. The amount 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 low, the flame retardancy of the thermoplastic polyester resin material becomes insufficient, laser light transmission, laser weldability is poor, conversely mechanical properties, too much separation. There is a problem of deterioration of moldability and bleed-out of flame retardant.

  In the present specification, the brominated polycarbonate 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 the nickel-containing colorant in combination with the brominated polycarbonate flame retardant, the laser light transmittance is good, and strong laser welding can be achieved in a shorter welding time, and further low warpage is excellent. It has also been 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, which is a complex salt-forming dye with nickel. Is preferred. Examples of the functional group of the complex salt dye that forms a complex salt with nickel include a hydroxyl group, a carboxyl group, an amino group, and the like.For example, an aromatic ring surrounding an azo group or an azomethine group, for example, these ortho-positions of the aromatic ring surrounding the benzene ring are used. Preferable examples include azo compounds and azomethine compounds having a functional group. Taking a monoazo dye as an example, a 1: 1 type metal complex salt dye in which one molecule of the monoazo dye has a Ni1 atom coordinated and a 1: 2 type in which two molecules of the monoazo dye (base material) have a Ni1 atom coordinated. There are metal complex dyes.

As a nickel-containing colorant, a C.I. I. SOLVENT Brown 53 is particularly preferred, and its chemical name is [2,3′-Bis [[(2-hydroxyphenyl) methylene] amino] but-2-enedinitriato (2-)-N2, N3, O2, O3] nickel. And 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 of 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 mass%, preferably 5 mass% or more, more preferably 10 mass% or more, preferably 30 mass% or less, more preferably 20 mass% or less. It is not more than mass%. If it is less than the above lower limit, the effect of improving flame retardancy may not be sufficient, and heat discoloration tends to occur. On the other hand, if the upper limit is exceeded, the blackness may be insufficient when the color 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, still more preferably 0.06 parts by mass or more, relative 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 discoloration tends to occur. If the upper limit is exceeded, the blackness may be insufficient when the color is adjusted to black.
Further, 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, further preferably 0.006% by mass or more, and particularly preferably 0.01 mass% or more, more preferably 0.8 mass% or less, further preferably 0.5 mass% or less, particularly preferably 0.3 mass% or less, and most preferably 0.1 mass% or less. . If it is less than the above lower limit value, the flame retardancy improving effect may not be sufficient, and if it is more than the above upper limit value, the blackness may be insufficient when the color tone is adjusted to black.

  The thermoplastic polyester resin material used in the present invention may contain an antimony compound in order to further improve flame retardancy. However, when the antimony compound is contained, the laser light transmittance is lowered, so that when the antimony compound is contained, the content thereof is preferably not more than 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 antimony compound is contained, the antimony compound has a bromine atom derived from the brominated polycarbonate flame retardant and a mass concentration of antimony atom derived from the antimony compound in the resin composition is 3 to 25% by mass in total. The content is preferably 4 to 22% by mass, more preferably 7 to 20% by mass, and if less than 3% by mass, the flame retardancy tends to decrease and exceeds 20% by mass. In addition, the mass ratio (Br / Sb) of bromine atom and antimony atom is preferably 1 to 15, more preferably 3 to 13, and 7 to 11 When the content is in such a range, the laser transmittance is less likely to decrease, and the laser weldability and the flame retardancy tend to be compatible with each other, which is preferable. There.

When the antimony compound is contained, it is preferably blended as a masterbatch with the thermoplastic polyester resin. As a result, the antimony compound (E) is likely 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 content 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 content of the antimony compound exceeds 90% by mass, the dispersibility of the antimony compound is apt to decrease, and when it is mixed with the thermoplastic polyester resin, the flame retardancy of the resin composition becomes unstable, and the masterbatch production The workability at that time is also significantly reduced. For example, when manufacturing using an extruder, problems such as strand instability 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, still more preferably 0.1 part by mass based on 100 parts by mass of the thermoplastic polyester resin. It is 1 part by mass or more, more preferably 0.8 parts by mass or less, further preferably 0.6 parts by mass or less, and particularly preferably 0.4 parts 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 phosphorous acid, phosphoric acid, phosphorous acid ester, and phosphoric acid ester. Among them, organic phosphate compounds, organic phosphite compounds or organic phosphonite compounds are preferable, and organic phosphate compounds are particularly preferable. .

The organic phosphate compound is preferably 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.)
Is a compound represented by.

In the above general formula, R ¹ is an alkyl group having 1 or more, preferably 2 or more, and usually 30 or less, preferably 25 or less, or an aryl group having 6 or more carbon atoms and usually 30 or less. It is more preferable that R ¹ is an alkyl group rather than an aryl group. When two or more R ^1's are present, the R ^1's may be the same or different.
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 octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, Hexadecyl group, octadecyl group, eicosyl group, triacontyl group and the like can be mentioned.

  Examples of the long-chain alkyl acid phosphate 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, cyclohexyl. Acid Phosphate, Phenoxyethyl Acid Phosphate, Alkoxy Polyethylene Glycol Acid Phosphate, Bisphenol A Acid Phosphate, Dimethyl Acid Phosphate, Diethyl Acid Phosphate, Dipropyl Acid Phosphate, Diisopropyl Acid Phosphate, Dibutyl Acid Phosphate, Geo Chill acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and a bis-nonylphenyl acid phosphate, or the like. Of these, octadecyl acid phosphate is preferable, and this is commercially available under the trade name "ADEKA STAB AX-71" by ADEKA.

  By blending the phosphorus-based stabilizer represented by the above general formula, particularly when containing a thermoplastic polyester resin and a polycarbonate resin, the transesterification reaction between the two is moderately suppressed, and the crystal of the thermoplastic polyester-based resin material is obtained. The oxidization temperature tends to be 190 ° C. or lower, whereby the laser transmittance and the laser weldability are more likely to be improved.

  The content of the phosphorus-based stabilizer is preferably 0.001 to 1 part by mass based on 100 parts by mass of the total amount of the thermoplastic polyester resin and other resins that are contained as necessary. When the content of the phosphorus-based stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in thermal stability and compatibility of the welding member, and a decrease in molecular weight during molding or deterioration of hue tends to occur. If it exceeds the amount, the amount tends to be excessive, and the occurrence 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, further preferably 0.05 to 0.4 parts by mass.

  As the phenol-based stabilizer, hindered phenol-based stabilizers are preferable, and examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3. 5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 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 ( 1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, 3,3 ′, 3 ″, , 5 ', 5 "-Hexa-tert-butyl-a, a', a"-(mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o -Cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) 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-triazin-2-ylamino) phenol, 2- [1- (2-hydroxy-3) 5-di -tert- pentylphenyl) ethyl] -4,6-di -tert- pentylphenyl acrylate.

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 available. preferable. Specific examples of such a phenolic antioxidant include "IRGANOX 1010", "IRGANOX 1076" manufactured by BASF (trade name, the same applies hereinafter), "ADEKA STAB AO-50" manufactured by ADEKA, and the like. Examples thereof include "ADEKA STAB AO-60".
In addition, 1 type may be contained and 2 or more types may be contained in the hindered phenolic stabilizer in arbitrary combinations and ratios.

  The content of the phenolic 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 the other resin that is contained as necessary. If the content is less than 0.01 parts by mass, the thermal stability tends to be lowered, and if it exceeds 1 part by mass, the laser transmittance may be lowered. The more preferable content is 0.05 to 0.8 parts by mass, and further preferably 0.1 to 0.6 parts by mass.

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

[Release agent]
The thermoplastic polyester resin material preferably further contains a release agent. As the release agent, known release agents usually used for polyester resins can be used, but among them, one or more release agents selected from polyolefin compounds, fatty acid ester compounds and silicone compounds can be 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, and more preferably 900 to 8,000 are preferable. Further, a modified polyolefin compound having a hydroxyl group, a carboxyl group, a non-hydroxyl group, an epoxy group, or the like introduced into its side chain is also particularly preferable.

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

  Further, the silicone compound is preferably a modified compound from the viewpoint of compatibility with the thermoplastic polyester resin. Examples of the modified silicone oil include silicone oil in which an organic group is introduced into the side chain of polysiloxane, silicone oil in which an organic group is introduced at both ends and / or one end of polysiloxane, and the like. Examples of the introduced organic group include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacryl group, a mercapto group, and a phenol group, 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 based on 100 parts by mass of the total amount of the thermoplastic polyester resin and other resins that are contained as necessary. If it is less than 0.05 parts by mass, the surface property tends to be deteriorated due to defective release at the time of melt molding, while if it exceeds 2 parts by mass, the workability of kneading the resin material is deteriorated, and the molded product is also formed. The surface may be cloudy. 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.

[Reinforcing filler]
It is also preferable that the thermoplastic polyester resin material further contains a reinforcing filler.
As the reinforcing filler, a commonly used inorganic filler for plastics can be used. Preferably, fibrous fillers such as glass fiber, carbon fiber, basalt fiber, wollastonite, potassium titanate fiber and the like can be used. Granular or amorphous fillers such as calcium carbonate, titanium oxide, feldspar minerals, clay, organized clay, glass beads; plate-like fillers such as talc; flaky fillers such as glass flakes, mica and graphite Materials can also be used.
Above all, it is preferable to use glass fibers from the viewpoint of laser light transmittance, mechanical strength, rigidity and heat resistance.

  As the reinforcing filler, it is more preferable to use one that has been surface-treated with a surface treatment 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, resistance to moist heat, hydrolysis resistance, and heat shock resistance.

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

Further, as the surface treatment agent, a novolac 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 combination of two or more kinds, and it is also preferable to use both in combination.

From the viewpoint of laser weldability, the glass fiber is also preferably a glass fiber having an anisotropic cross-sectional shape in which the ratio of the major axis to the minor axis in the cross section is 1.5 to 10.
The cross-sectional shape is preferably an elliptical, elliptical, or eyebrows-shaped cross section, and an oval cross section is particularly preferable. Further, those having a ratio of major axis / minor axis of 2.5 to 8, more preferably 3 to 6, are preferable. Furthermore, when the major axis of the glass fiber cross section 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. Use of such flat glass fibers suppresses warpage of the molded product, and is particularly effective when manufacturing a box-shaped welded body.

  The content of the reinforcing filler is 0 to 100 parts by mass with respect to a total of 100 parts by mass of the thermoplastic polyester resin and other resins that are contained as necessary. When the content of the reinforcing filler exceeds 100 parts by mass, fluidity and laser weldability are deteriorated, which is not preferable. A more preferable content of the reinforcing filler is 5 to 90 parts by mass, more preferably 15 to 80 parts by mass, further preferably 20 to 70 parts by mass, and particularly 30 to 60 parts by mass.

[Production of thermoplastic polyester resin material]
The thermoplastic polyester resin material of the present invention can be produced by a conventional method for preparing a resin composition. Usually, each component and various additives optionally added are mixed well and then melt-kneaded in a single-screw or twin-screw extruder. It is also possible to prepare the resin material of the present invention without premixing the respective components, or premixing only a part thereof, supplying the mixture to an extruder using a feeder and melt-kneading.
Furthermore, a thermoplastic polyester resin and, if necessary, a part of the other resin contained and a part of the other component are mixed and melt-kneaded to prepare a masterbatch, and then the other remaining The components may be blended and melt-kneaded.
When a fibrous reinforcing filler such as glass fiber is used, it is also preferable to supply it from a side feeder in the middle of the cylinder of the extruder.

  The heating temperature at the time of melt kneading can be appropriately selected usually from the range of 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 the screw configuration considering shear heat generation and the like.

  The laser-welded molded product obtained by molding the thermoplastic polyester-based resin material used in the present invention preferably forms a matrix phase in which the thermoplastic polyester resin is continuous in the surface layer portion of the molded product, and is a brominated polycarbonate-based resin. The phase of the flame retardant is dispersed and present 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 flame retardant phase is preferably in the range of 1 to 5. Since the brominated polycarbonate flame retardant phase disperses without stretching as much as other flame retardants, it is thought that the internal diameter of the laser light is small and the laser light transmittance is good because the ratio of the major axis to the minor axis is small. To be The ratio of major axis / minor axis is more preferably 1.2 to 4, and still more preferably 1.4 to 3.

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

  FIG. 3 shows an example of the morphology of the molded article of the present invention, which is a photograph of the backscattered electron image of the surface layer portion of the molded article obtained in Example 20 described later by SEM / EDS analysis (magnification: 3,000 times). ). In FIG. 3, it is the polybutylene terephthalate resin phase that constitutes the black gray continuous phase (matrix 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 or adjusting the lightness or darkness of the image obtained by the backscattered electron image, or both adjustments. 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 refers to the maximum length of the flame retardant phase, and the minor axis refers to the shortest diameter of the lengths perpendicular to the major axis. The ratio of the major axis to the minor axis of the brominated polycarbonate flame retardant phase of Reference Example 1 (major axis / minor axis) was 2.7.

By having such a unique morphological structure as described above, a molded product having excellent laser light transmissivity, laser weldability, flame retardancy, and low warpage 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, but by mixing the raw material components and simply kneading, the above morphology structure is obtained. Is difficult to form stably, and kneading by a special method is recommended.
Hereinafter, a preferable manufacturing method for stably forming such a morphological structure when a polybutylene terephthalate resin as a main component is contained as the thermoplastic polyester resin will be described.

Polybutylene terephthalate resin, brominated polycarbonate flame retardant, nickel-containing colorant and other components to be blended as needed are mixed at a predetermined ratio and then supplied to a single-screw or twin-screw extruder equipped with a die nozzle. After that, the mixture is melt-kneaded, the resin composition is extruded from a die nozzle to form a strand, and then cut into 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 screw diameter D (mm), satisfies the relationship of 15 <(L / D) <100, and 20 <(L It is more preferable to satisfy / D) <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 article is unlikely to be in the range of 1 to 5, and conversely, even when it is 100 or more, the heat of the brominated polycarbonate flame retardant is reduced. It is not preferable because the deterioration may be remarkable.
The shape of the die nozzle is not particularly limited, but in terms of pellet shape, 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.

  Further, when supplying the raw materials to the melt kneader such as an extruder, prior to melt kneading, a brominated polycarbonate flame retardant, a nickel-containing colorant and other components to be blended as necessary are blended in advance, It is preferable that the preblend is supplied to a melt-kneader such as an extruder from a feeder provided separately from the polybutylene terephthalate resin. When the nickel-containing coloring agent is blended as a master touch, it should be blended with the polybutylene terephthalate resin in advance, and the pre-blend of other components should be supplied from a separate feeder to a melt-kneader such as an extruder. Is preferred. By adopting such a supply method, 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 it becomes easier to achieve both laser welding and flame retardancy. preferable.

  The melting temperature of the resin composition at the time of melt-kneading is preferably 200 to 330 ° C, more preferably 220 to 315 ° C. If the melting temperature is less than 200 ° C., insufficient melting occurs, 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 is 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 in the range of 1 to 5, and when it exceeds 1,200 rpm, the antimony compound is contained. In this case, the antimony compound is likely to aggregate, which may deteriorate the laser light transmittance and mechanical properties, which is not preferable.
The discharge rate 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 article tends to be in the range of 1 to 5, and when the antimony compound is contained, it is caused by aggregation of the ammon compound. Laser light transmission and mechanical properties are less likely to deteriorate, which is preferable.

Shear rate of the resin composition in the die nozzle is preferably 50～10,000Sec ^-1, more preferably 70～5,000Sec ^-1, more preferably from 100～1,000Sec ^-1 . The shear rate is generally determined by the discharge amount of the resin composition and the shape of the cross section of the die nozzle. For example, when the die nozzle has a circular cross section, it can be calculated by γ = 4Q / πr ^3. it can. Here, γ represents the shear rate (sec ⁻¹ ), Q represents the discharge amount (cc / sec) of the resin composition per die nozzle, and r represents the radius (cm) of the die nozzle cross section.

  The resin composition extruded in a strand form from the die nozzle is cut into pellets by 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 preferred to cool the strands to a temperature of 0 ° 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. For such water cooling, the strands may be cooled by passing them 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 pellets produced in this manner is preferably 1 to 9 mm, more preferably 2 to 8 mm, further preferably 3 to 6 mm, and preferably 1 to 11 mm in length when the columnar shape is cylindrical. 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 when the strand is cut is
1.5 × 10 ³ <(γ · T) <1.5 × 10 ⁶
By satisfying the above relationship, the ratio of the major axis / minor axis of the brominated polycarbonate flame retardant phase in the surface layer of the molded body is likely to be in the range of 1 to 5, and it becomes easier to achieve both laser welding and flame retardancy. Further, when the value of (γ · T) is 1.5 × 10 ³ or less, the surface of the molded product is liable to be roughened due to poor dispersion of each component of the resin composition, and laser light transmission, flame retardancy, Mechanical properties tend to be unstable. On the other hand, when the content exceeds 1.5 × 10 ⁶ , on the other hand, when the antimony compound is contained, the antimony compound may be aggregated and the laser light transmittance and mechanical properties may be deteriorated, which is not preferable. The lower limit of (γ · T) is more preferably 3.3 × 10 ³ , and the upper limit thereof is more preferably 9.5 × 10 ⁵ .
In order to adjust the value of (γ · T) within the above range, the 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 preferred conditions alone or in combination of two or more, but among them, (γ · T) It is effective to adopt manufacturing conditions such that the value of satisfies the above formula.

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

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

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

2) The content of the chlorine compound as an impurity in the brominated polycarbonate 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 mass% or less, and particularly preferably 0.03 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, 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 value in terms of decane by analyzing a gas generated by heating at 270 ° C. for 10 minutes by a gas chromatography method.

3) Setting the amounts of free bromine, chlorine, and sulfur in the thermoplastic polyester-based resin material to a specific amount or less is also effective in facilitating 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 the removal of the content to 0 mass ppm requires purification that neglects the economical efficiency, the lower limit is usually 1 mass ppm, preferably 5 mass ppm, and 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, particularly preferably 150 mass ppm or less. The chlorine content in the thermoplastic polyester-based resin material is not limited to the state and form of chlorine present in the resin composition. Since chlorine is mixed in from various environments such as raw materials used, additives, catalysts, polymerization atmosphere, cooling water of resin, etc., it is preferable to control the total content of chlorine to be 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, particularly preferably 100 mass ppm or less. The sulfur content in the thermoplastic polyester resin material is not limited to the state and form of sulfur present in the resin composition. Sulfur is mixed in from various environments such as raw materials used, additives, catalysts, polymerization atmospheres, etc., so it is preferable to control the total amount of these to be 250 mass ppm or less.

  The contents of free bromine, chlorine and sulfur in the thermoplastic polyester resin material can be measured by the combustion ion chromatography method. Specifically, using an automatic sample combustor of "AQF-100 type" manufactured by Mitsubishi Chemical Analytech Co., Ltd., the resin composition is heated under an argon atmosphere at 270 ° C. for 10 minutes to generate bromine, chlorine, The amount of sulfur can be determined by quantitatively using "ICS-90" manufactured by Nippon Dionex.

  These methods 1) to 3) are preferably applied singly or in combination of two or more, and are also possible 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 product having the above-mentioned preferable morphology structure, for example, the screw configuration of the injection molding machine, the processing of the inner wall of the screw or the cylinder, the nozzle diameter, the selection of the molding machine conditions such as the mold structure, and the plasticity Various methods can be used, such as liquefaction, metering, adjustment of molding conditions such as injection, addition of other components to the molding material and the like. In particular, it is preferable to adjust, for example, the cylinder temperature, the back pressure, the screw rotation speed, the injection speed, and the like as conditions during plasticization, measurement, 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 the injection speed is adjusted, it is preferably set to 5 to 1,000 mm / sec, more preferably 10 to 900 m / sec, further 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 a usual method can be used. The molded body (first member) of the thermoplastic polyester-based resin material is set on the permeate side, and the resin molded body of the mating material (second member, adherend) is brought into contact (particularly at least the welded portion is in surface contact), By irradiating with laser light, the two types of molded bodies are welded and integrated to form one molded product.

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

[Manufacture of laser transparent material for welding]
The components described in Table 1 above were blended in the amounts described as permeating agent compositions A to G in Table 2 below (all are parts by mass), and this was blended using a 30 mm vent type twin-screw extruder at 250 ° C. The mixture was kneaded and extruded into strands to obtain pellets of transmitting material compositions A to G.
The crystallization temperature (Tc) of the resin composition was measured using a differential scanning calorimeter (DSC) machine ("Pyris Diamond" manufactured by Perkin Elmer Co., Ltd.) under a nitrogen atmosphere to a temperature rising rate of 20 to 300C, and a temperature rising rate of 20C / min. It was measured as the peak top temperature of the exothermic peak observed when the temperature was raised at 3, the temperature was held at 300 ° C. for 3 minutes, and then the temperature was lowered at a temperature lowering rate of 20 ° C./min.
The results are shown in Table 2.

Also, using a melt indexer manufactured by Takara Industry Co., Ltd., the obtained pellets were dried at 120 ° C. for 5 hours, 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. flow volume MVR ^(unit: cm 3 / 10min) was measured.
The results are shown in Table 2.

After drying the obtained pellets of the permeable material compositions A to G for 5 hours at 120 ° C., with an injection molding machine (NEX80-9E manufactured by NISSEI PLASTIC INDUSTRIES CO., LTD.), A cylinder temperature of 255 ° C., a mold temperature of 60 ° C., Injection molding was performed at an injection speed of 73 mm / sec and an injection rate of 48 cm ³ / 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 mold temperature was measured during manufacturing. There are two measurement sites, the movable side and the fixed side of the mold, and the molded product has a distance of 15 mm from the film gate 1 as shown in FIG. When the mold surface temperature was measured with a contact mold thermometer, it was confirmed to be within the range of 60 ± 3 ° C.
From the obtained molded product, as shown in FIG. 1, from a position where the distance from the film gate 1 is 10 mm, 25 mm, and 40 mm, a transparent material 1 (site-1) to a transparent material 3 (width of 10 mm × length 40 mm) to a transparent material 3 ( Part-3) was cut out.
In addition, except that the injection speed was changed to 100 mm / sec and the injection rate was 66 cm ³ / sec, the transmission material 1 (site-1) to the distance from the film gate 1 was 10 mm, 25 mm, and 40 mm in the same manner as above. The transparent material 3 (site-3) was cut out. In addition, 4 in FIG. 1 shows the laser irradiation location in the later-described laser welding evaluation.

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

[Laser welding evaluation]
(Examples 1 to 15, Comparative Examples 1 to 13)
Among the permeable materials shown in Table 2 obtained above, with a thickness of 1 mm and 1.5 mm, the permeable material composition and parts shown in Table 3 (thickness 1 mm) and Table 4 (thickness 1.5 mm), The following laser welding tests were performed with each of the transmission materials of the injection speed, the injection rate, the surface progress coefficient, and the transmittance as the transmission side.
Pellets obtained in the same manner as the above-mentioned transmitting material were used, except that the resin composition for laser absorbing material having the following composition was used, and the cylinder temperature was 255 ° C., the mold temperature was 60 ° C., the injection speed was 73 mm / sec, the injection rate was 48 cm. ^{Under the conditions of 3} / sec and surface progression coefficient: 480 cm ³ / sec · cm, a molded product having the same length of 60 mm × width of 60 mm × thickness of 1 mm as the above-mentioned transparent material was formed. From the obtained molded product, a part-2 was cut out in the same manner as the transmitting material, and used as a laser absorbing member (absorbing material A).
Polybutylene terephthalate resin Nova Duran (registered trademark, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) 5008: 67.4 mass%
Glass fiber T-187 (manufactured by Nippon Electric Glass Co., Ltd.): 30% by mass
Stabilizer Adeka Sizer EP-17 (made by ADEKA): 0.4% by mass
Stabilizer ADEKA STAB AO-60 (made by ADEKA): 0.2% by mass
Carbon black mass batch (80% by weight of Novaduran 5008, 20% by weight of carbon black): 2% by weight

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

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

The laser welding strength of the welded welded body was measured. The welding strength was measured by using a tensile tester (“5544 type” manufactured by Instron Co., Ltd.), and the transparent material 2 and the absorbent material 3 which were welded and integrated were sandwiched by clamps at both ends in the long axis direction. It was evaluated by pulling at a pulling speed of 5 mm / min. The laser welding strength is indicated by the tensile shear fracture strength of the welded portion.
The results of the welding test are shown in Tables 3, 4 and 5 below.

(Examples 16-18)
Using pellets obtained in the same manner as the above-mentioned transmitting material except that the resin composition for laser absorbing material 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. / Sec, an injection rate of 48 cm ³ / sec, and a surface progression coefficient of 480 cm ³ / sec · cm, a molded product having the same length of 60 mm × width of 60 mm × thickness of 1 mm was molded. The obtained molded product was cut out from the portion of site-2 in the same manner as the transmitting material, and used as laser absorbing members (absorbing materials B to D).

Table 7 below shows the results of a welding test in which laser welding was performed on the transmissive material of the transmissive material composition A (site-2) in the same manner as in Example 1 except that the above-described absorbent materials B to D were used.

(Examples 19 to 21)
The components shown in Table 8 below were used.

Of 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 blended in advance with a blender in an amount (parts by mass) described in Table 9 below (blend). Object 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 2). The resulting blend 1 and blend 2 were fed to the hopper from two independent dedicated feeders so that the proportions (parts by mass) shown in Table 8 would be obtained, and this was fed with a 30 mm vent type biaxial Using an extruder (manufactured by Nippon Steel Co., Ltd., "TEX30α"), glass fiber was supplied from the seventh side feeder from the hopper, and the extruder barrel set temperature C1 to C15 was 270 ° C, the die was 260 ° C, and the discharge was 80 kg. / Hr, screw rotation speed 280 rpm, number of nozzles 5 holes (circular (φ4 mm), length 1.5 cm), shear rate (γ) 664 sec ⁻¹ , melt kneading and extruded into strands. The strand temperature immediately after extrusion was 275 ° C.
The extruded strand was introduced into a water bath whose temperature was adjusted to 40 to 80 ° C. and cooled. The strand surface temperature (T) is cooled to 110 ° C. at a temperature measured by an infrared thermometer (γ · T = 7.3 × 10 ⁴ ), inserted into a pelletizer and cut to obtain a polybutylene terephthalate resin composition. Of pellets were obtained.

  The properties of the obtained resin composition pellets were, except for those mentioned otherwise, 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, The following test pieces injection-molded under the conditions of an injection pressure 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. In molding, the resin composition pellets were dried at 120 ° C. for 6 to 8 hours immediately before.

After drying the pellets of the resin composition obtained by the above method at 120 ° C. for 6 hours, a cylinder temperature of 255 ° C. and a mold temperature of 60 ° C. were measured by an injection molding machine (NEX80-9E manufactured by Nissei Plastic 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 progression 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 transparent material having a width of 10 mm and a length of 40 mm was cut out from a position (part-3) at a distance of 40 mm from the film gate 1.

The following evaluation was performed.
(1) Transmittance Using the spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corp.), the laser transmittance of the central portion of the transparent material obtained above was measured at a transmittance of 940 nm (unit:%). It was measured.
(2) Flame retardance A test piece for UL94 test (125 mm × 12.5 mm × 3.0 mmt) was molded from the obtained resin composition pellets, and in accordance with UL94 standard, V-0, V-1, V -2 was judged.
(3) Bending Strength An ISO multipurpose test piece (4 mm thickness) was molded from the obtained resin composition pellet, and the maximum bending strength (unit: MPa) was measured at a temperature of 23 ° C. according to ISO178.

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

(5) Ratio of major axis / minor axis of brominated polycarbonate flame retardant phase in the surface layer The central surface layer of the permeating material obtained above (the surface layer having a cross-sectional depth of less than 20 μm, in the resin composition flowing direction). An ultrathin section having a thickness of 300 nm was cut out with a diamond knife using “UC7” manufactured by Leica. The obtained ultrathin section was stained with ruthenium tetroxide for 210 minutes, and then subjected to SEM observation with a scanning electron microscope "SU8020" manufactured by Hitachi High-Tech Co., Ltd. at an acceleration voltage of 1.5 to 2 kV.
A photograph of the backscattered electron image of the surface layer portion of the molded body obtained in Example 20 by SEM / EDS analysis is shown in FIG.
The major axis and the minor axis of the brominated polycarbonate flame retardant phase were determined by measuring 50 of the brominated polycarbonate flame retardant phases and averaging them.

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

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

Laser welding strength:
Laser welding uses a laser device manufactured by Fine Devices (laser 140W, fiber core diameter 0.6 mm), laser wavelength: 940 nm, laser scan speed: 40 mm / sec, scan length: 10 mm, laser output: 20 W, pressurization: 0. The pressure was 0.4 MPa and the distance between the laser head and the transparent material 2 was 79.7 mm.
Laser welding strength measurement was performed using a welded body that was welded and integrated. The welding strength was measured by using a tensile tester (“5544 type” manufactured by Instron Co., Ltd.), and the transparent material 2 and the absorbent material 3 which were welded and integrated were sandwiched by clamps at both ends in the long axis direction. It was evaluated by pulling at a pulling speed of 5 mm / min. The laser welding strength is indicated by the tensile shear fracture strength (unit: N) of the welded portion.

Laser welding processability:
A laser welding test was conducted under the same conditions as in the above laser welding strength measurement except that the laser scanning speed was changed variously every 5 mm / sec. The fastest scan speed that can achieve a laser welding strength of 100 N or more was determined 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 transparency and laser welding processability, and since a molded product obtained by laser welding this is excellent in welding strength, it is an electrical component for transportation equipment such as automobiles, electrical and electronic parts. It can be suitably used for equipment parts, industrial machine parts, and other consumer parts.

1: Film gate 2: Laser absorber 2
3: Laser transparent material 3
4: Laser irradiation point

Claims (7)

A first laser welding member formed by injection-molding a thermoplastic polyester resin material and a second member made of a resin material having laser absorbability are irradiated with laser light from the first laser welding member side. A method for producing a laser-welded molded article, which comprises laser-welding
The thermoplastic polyester resin material for the first laser welding member,
A polybutylene terephthalate resin and a polyethylene terephthalate resin are contained, and the content of the polyethylene terephthalate resin is 5 to 50 mass% with respect to 100 mass% of the total of the polybutylene terephthalate resin and the polyethylene terephthalate resin, or
30 to 90% by mass of polybutylene terephthalate resin, 1 to 50% by mass of polystyrene and / or butadiene rubber-containing polystyrene, and 1 to 50% by mass of polycarbonate resin (total 100% by mass),
The resin material of the second member is a thermoplastic polyester resin composition, containing carbon black or a laser light absorbing dye,
The portion of the first member to be laser-welded is located at a position 15 mm or more away from the gate of the injection molding die, and has a light transmittance of 45 % or more with respect to a laser beam having a wavelength of 940 nm. A method for producing a laser-welded molded article. The thermoplastic polyester resin material for the first laser welding member is 30 to 90 mass% of polybutylene terephthalate resin, 1 to 50 mass% of polystyrene containing polystyrene and / or butadiene rubber, and 1 to 50 mass% of polycarbonate resin. The method for producing a laser-welded molded article according to claim 1, wherein the method is mass% (total is 100 mass%). The method for producing a laser-welded molded article according to claim 1 or 2, wherein in the thermoplastic polyester resin composition of the second member, 50% by mass or more of the polyester resin is a polybutylene terephthalate resin. The method for producing a laser-welded laser-welded product according to claim 1, wherein the resin material forming the first member and the second member further contains glass fiber. The laser weldable member, under the conditions of an injection rate 10~300cm ³ / sec, which is defined below, any one of claims 1 to 4, the thermoplastic polyester resin material is a member formed by injection molding A method for producing a laser-welded molded article according to 1 .
Injection rate: Resin material capacity per unit time injected from the discharge nozzle of the injection molding machine into the mold cavity The laser weldable member, under the conditions defined by the surface progression factor 100~1200cm ³ / sec · cm below any of claims 1 to 5, wherein the said thermoplastic polyester resin material is a member formed by injection molding 2. A method for producing a laser-welded molded article according to item 1 .
Surface Progression Coefficient: A value obtained by dividing the injection rate by the thickness of the mold cavity in which the resin material is injected. Melt volume rate of the thermoplastic polyester resin material (250 ° C., measured under the conditions of a load 5 kg) is laser-welded molded product according to any one of claims 1 to 6 is 10 cm ^3/10 minutes or more Manufacturing method .