JP2016216530A - Resin composition for laser welding and welding body thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for laser welding that has high laser transmittance and excellent laser welding properties, and is also excellent in the appearance and weather resistance of a molding, and provide a molding for laser welding and a laser welding body.SOLUTION: A resin composition for laser welding comprises, based on (A) thermoplastic polyester resin 100 pts.mass, 10-100 pts.mass of (B) glass fibers with an average fiber diameter of more than 15 μm and/or (C) glass beads with an average particle diameter of 25 μm or more.SELECTED DRAWING: None

Description

  The present invention relates to a laser-welded resin composition and a welded body, and more specifically, a laser-welded resin composition having high laser light permeability and excellent laser weldability, and excellent appearance and weather resistance of a molded product, and The present invention relates to a welded body obtained by laser welding a molded product comprising the same.

In recent automobile parts and consumer parts, from the viewpoint of environment such as weight reduction and recycling, parts that have conventionally used metals have been made resin, and resin products have been downsized. Thermoplastic polyester resin is excellent in mechanical strength, chemical resistance, electrical insulation, etc., and has excellent heat resistance, moldability, and recyclability, so it is widely used in various equipment parts. ing. In particular, polybutylene terephthalate resin and the like are widely used in electrical and electronic parts that require fire safety because they are excellent in mechanical strength and moldability and can be flame retardant.
In recent years, in order to manufacture these equipment parts, examples of joining parts by welding processing for increasing productivity have been increasing, and laser welding, which has little influence on electronic parts, has been frequently used. Yes.

  However, compared to polycarbonate resins and polystyrene resins, polyester resins, especially polybutylene terephthalate resins, are relatively low in laser transmission, and because the molded product tends to warp, the welding strength may be insufficient. There were many.

  Moreover, when using for the use in which high mechanical strength and rigidity are required, fillers, such as glass fiber and glass flake, are added and these characteristics are improved. However, when fillers such as glass fibers and glass flakes are added, there is a problem that the transmittance of laser light is lowered. In addition, there is a problem that the initial appearance of the molded product is deteriorated due to the influence of floating of the filler or the weather resistance is lowered.

  In Patent Document 1, by blending a glass fiber having a flat cross section perpendicular to the fiber length direction, the mechanical properties and transmittance of the molded product are improved, and laser welding thermoplasticity is excellent in laser welding properties. A resin composition is disclosed. However, there are cases where sufficient laser light transmission cannot always be achieved by the method of making the glass fiber flat, and strong welding strength may not be obtained. In addition, it was not sufficient in terms of appearance and weather resistance of the molded product.

International Publication No. 2007/046536

  An object of the present invention is to provide a laser-welded polyester-based resin composition that eliminates the above-mentioned problems, has high laser light transmittance, is excellent in laser weldability, and is excellent in appearance and weather resistance of a molded product, and a molded product comprising the same. It is in providing the welded body which welded.

The inventor of the present invention has disclosed that a polyester resin composition containing glass fibers having an average fiber diameter of more than 15 μm or glass beads having an average particle diameter of 25 μm or more in a thermoplastic polyester resin has significantly increased laser light transmittance and laser welding. The present invention has been completed by finding that it has excellent properties and is excellent in appearance and weather resistance of a molded product.
The present invention is as follows.

[1] (B) glass fiber having an average fiber diameter of more than 15 μm and / or (C) glass beads having an average particle diameter of 25 μm or more are contained in 10 to 100 parts by mass of (A) thermoplastic polyester resin. A resin composition for laser welding, characterized by comprising:
[2] The laser welding resin composition as described in [1] above, wherein the (A) thermoplastic polyester resin contains a polybutylene terephthalate resin.
[3] The resin composition for laser welding as described in [1] or [2] above, wherein the crystallization temperature (Tc) of the resin composition is 190 ° C. or lower.
[4] A laser welding molded product obtained by molding the laser welding resin composition according to any one of [1] to [3].
[5] The molded article for laser welding according to [4], which is used on the transmission side during laser welding.
[6] A laser welded body laser-welded using the molded product according to the above [4] or [5].

The resin composition for laser welding according to the present invention has a high laser light transmittance, a laser welding processability, and a welded product with high welding strength, and a molded product is also excellent in appearance and weather resistance.
As described above, glass fiber has been proposed as a reinforcing filler for polyester resin, but the fiber diameter of glass fiber that is usually used or marketed is at most about 13 μm. The glass fiber used in the present invention exceeds the fiber diameter of ordinary glass fibers that are generally commercially available, and by using this, the number of glass fibers to be blended can be reduced, and even inside the resin composition, the inside of laser light Scattering is greatly reduced and the transmittance is increased, so that high laser weldability can be achieved. Moreover, since the number of the glass fibers to mix | blend can be decreased, it is guessed that the surface appearance defect and the weather resistance fall by the float etc. on the surface of the molded article of glass fiber can be suppressed, and the above effects are expressed. Glass beads having an average particle size of 25 μm or more are considered to exhibit the same effect due to the same phenomenon.

It is a perspective view of the ASTM No. 4 dumbbell piece which is a laser-transmitting molded product used in the laser welding strength test in Examples.

[Summary of Invention]
The resin composition for laser welding of the present invention has (B) glass fiber having an average fiber diameter of more than 15 μm and / or (C) an average particle diameter of 25 μm or more with respect to (A) 100 parts by mass of the thermoplastic polyester resin. It contains 10 to 100 parts by mass of glass beads.

Hereinafter, the contents of the present invention will be described in detail.
The description of each constituent element described below may be made based on typical embodiments and specific examples of the present invention, but the present invention is interpreted to be limited to such embodiments and specific examples. It is not a thing. In the specification of the present application, “to” is used in the sense of including the numerical values described before and after it as the lower limit value and the upper limit value.

[(A) Thermoplastic polyester resin]
The thermoplastic polyester resin (A) which is the main component of the resin composition of the present invention 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. It may be either a homopolyester or a copolyester.

(A) As a dicarboxylic acid compound which comprises a thermoplastic polyester resin, aromatic dicarboxylic acid or its ester-forming derivative is used preferably.
Examples of aromatic dicarboxylic acids 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, diphenyl ether-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, etc. Refutaru acid can be preferably used.

These aromatic dicarboxylic acids may be used as a mixture of two or more. As is well known, these compounds can be used in polycondensation reactions with dimethyl esters or the like as ester-forming derivatives in addition to free acids.
If the amount is small, together with these aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1 One or more alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid can be mixed and used.

(A) Examples of the dihydroxy compound constituting the thermoplastic polyester resin include ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, and triethylene glycol. Examples thereof include aliphatic diols, alicyclic diols such as cyclohexane-1,4-dimethanol, and mixtures thereof. If the amount is small, one or more kinds of 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.
In addition, aromatic diols such as hydroquinone, resorcin, naphthalenediol, dihydroxydiphenyl ether, and 2,2-bis (4-hydroxyphenyl) propane can also be used.

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

  As the (A) thermoplastic polyester resin, usually, a resin mainly composed of polycondensation of a dicarboxylic acid and a diol, that is, a resin comprising 50% by mass, preferably 70% by mass or more of the entire resin, is composed of this polycondensate. The dicarboxylic acid is preferably an aromatic carboxylic acid, and the diol is preferably an aliphatic diol.

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

(A) The intrinsic viscosity of the thermoplastic polyester 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 the intrinsic viscosity is lower than 0.5 dl / g, the resulting resin composition tends to have a low mechanical strength. If it is higher than 2 dl / g, the fluidity of the resin composition may deteriorate and the moldability may deteriorate, or the laser weldability may decrease.
In addition, the intrinsic viscosity of the (A) thermoplastic polyester resin is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

  (A) The terminal carboxyl group amount 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 30 eq / ton or less. Is more preferable. If it exceeds 50 eq / ton, gas tends to be generated during melt molding of the resin composition. Although the lower limit of the amount of terminal carboxyl groups is not particularly defined, it is usually 10 eq / ton.

  The amount of terminal carboxyl groups of (A) thermoplastic polyester resin is a value measured by titration using a 0.01 mol / l benzyl alcohol solution of sodium hydroxide by dissolving 0.5 g of polyester resin in 25 mL of benzyl alcohol. It is. As a method for adjusting the amount of terminal carboxyl groups, a conventionally known arbitrary method such as a method for adjusting polymerization conditions such as a raw material charge ratio during polymerization, a polymerization temperature, a pressure reduction method, a method for reacting a terminal blocking agent, etc. Just do it.

  Especially, it is preferable that (A) thermoplastic polyester resin contains a polybutylene terephthalate resin, and it is preferable that 50 mass% or more in (A) thermoplastic polyester resin is a polybutylene terephthalate resin.

  Polybutylene terephthalate resin is manufactured by batch polymerization or continuous polymerization of dicarboxylic acid components mainly composed of terephthalic acid or their ester derivatives and diol components mainly composed of 1,4-butanediol. can do. In addition, after producing a low molecular weight polybutylene terephthalate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further solid-phase polymerization under a nitrogen stream or under reduced pressure.

  The polybutylene terephthalate resin is preferably produced by a continuous melt polycondensation of a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of 1,4-butanediol.

  The catalyst used in performing 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. Of these, titanium compounds are particularly preferred. 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”). Examples thereof include polyester ether resins copolymerized with alkylene glycols (particularly polytetramethylene glycol), dimer acid copolymerized polybutylene terephthalate resins, and isophthalic acid copolymerized polybutylene terephthalate resins.

When the polyester ether resin copolymerized with polytetramethylene glycol is used as the modified polybutylene terephthalate resin, the proportion of the tetramethylene glycol component in the copolymer is preferably 3 to 40% by mass, and 5 to 30% by mass. % Is more preferable, and 10 to 25% by mass is more preferable. By setting it as such a copolymerization ratio, it tends to be excellent in the balance between laser weldability and heat resistance, which is preferable.
When using a dimer acid copolymerized polybutylene terephthalate resin 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 the carboxylic acid group, 1-20 mol% is more preferable, and 3-15 mol% is further more preferable. By setting it as such a copolymerization ratio, it exists in the tendency which is excellent in the balance of laser weldability, long-term heat resistance, and toughness, and is preferable.
When the isophthalic acid copolymerized polybutylene terephthalate resin is used as the modified polybutylene terephthalate resin, the ratio 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 more preferable. By setting it as such a copolymerization ratio, it exists in the tendency which is excellent in the balance of laser weldability, heat resistance, injection moldability, and toughness, and is preferable.
Among the modified polybutylene terephthalate resins, polyester ether resins copolymerized with polytetramethylene glycol and isophthalic acid copolymerized polybutylene terephthalate resins are preferable.

  And preferable content of these copolymers is 5-50 mass% in the total amount of 100 mass% of (A) thermoplastic polyester resin, Furthermore, 10-40 mass%, Especially 15-30 mass%. .

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 the intrinsic viscosity is lower than 0.5 dl / g, the resulting resin composition tends to have a low mechanical strength. On the other hand, if it is higher than 2 dl / g, the fluidity of the resin composition may be deteriorated and the moldability may be deteriorated or the laser weldability may be deteriorated.
The intrinsic viscosity is a value measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

  The terminal carboxyl group amount 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 40 eq / ton or less. More preferably, it is 30 eq / ton or less. If it exceeds 50 eq / ton, gas tends to be generated during melt molding of the resin composition. Although the lower limit of the amount of terminal carboxyl groups is not particularly defined, it is usually 10 eq / ton in consideration of the productivity of production of polybutylene terephthalate resin.

  The amount of terminal carboxyl groups of the polybutylene terephthalate resin is a value measured by titration using a 0.01 mol / l benzyl alcohol solution of sodium hydroxide by dissolving 0.5 g of the polyalkylene terephthalate resin in 25 mL of benzyl alcohol. is there. As a method for adjusting the amount of terminal carboxyl groups, a conventionally known arbitrary method such as a method for adjusting polymerization conditions such as a raw material charge ratio during polymerization, a polymerization temperature, a pressure reduction method, a method for reacting a terminal blocking agent, etc. Just do it.

(A) As a thermoplastic polyester resin, what contains polybutylene terephthalate homopolymer and the said modified polybutylene terephthalate resin is also preferable. By containing a specific amount of the modified polybutylene terephthalate resin, the laser transmittance and laser weldability are easily improved, which is preferable.
When the polybutylene terephthalate homopolymer and the modified polybutylene terephthalate resin are contained, the modified polybutylene terephthalate resin is preferably used with respect to 100% by mass in total of the polybutylene terephthalate homopolymer and the modified polybutylene terephthalate resin. It is 10-70 mass%, More preferably, it is 20-65 mass%, More preferably, it is 30-60 mass%. When the content of the modified polybutylene terephthalate resin is less than 10% by mass, the laser welding strength tends to decrease. When the content exceeds 70% by mass, the moldability may be remarkably decreased.

Furthermore, (A) the thermoplastic polyester resin preferably contains a polybutylene terephthalate resin and a polyethylene terephthalate resin. By containing a specific amount of polyethylene terephthalate resin, the 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 polyterylene terephthalate resin and the polyethylene terephthalate resin is preferably 5 to 50% by mass with respect to the total 100% by mass of the polybutylene terephthalate resin and the polyethylene terephthalate resin. More preferably, it is 10-45 mass%, More preferably, it is 15-40 mass%. When the content of the polyethylene terephthalate resin is less than 5% by mass, the laser welding strength tends to decrease, and when it exceeds 50% by mass, the moldability may be significantly decreased.

  Polyethylene terephthalate resin is a resin mainly composed of oxyethyleneoxyterephthaloyl units composed of terephthalic acid and ethylene glycol with respect to all structural repeating units, and includes structural repeating units other than oxyethyleneoxyterephthaloyl units. Also good. The polyethylene terephthalate resin is produced using terephthalic acid or a lower alkyl ester thereof and ethylene glycol as main raw materials, but other acid components and / or other glycol components may be used together as raw materials.

  Acid components other than terephthalic acid include phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenylsulfone dicarboxylic 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, aliphatic glycols such as pentamethylene glycol, hexamethylene glycol, and neopentyl glycol, cyclohexane Examples 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, a trifunctional acid such as tricarballylic acid, trimellitic acid, trimellitic acid or the like, or an acid having tetrafunctional ester form performance such as pyromellitic acid, or glycerin, trimethylolpropane, Copolymerized alcohol having a trifunctional or tetrafunctional ester-forming ability such as pentaerythritol in an amount of 1.0 mol% or less, preferably 0.5 mol% or less, more preferably 0.3 mol% or less. 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 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

Moreover, it is preferable that the density | concentration of the terminal carboxyl group of a polyethylene terephthalate resin is 3-50 eq / ton, especially 5-40 eq / ton, Furthermore, it is preferable that it is 10-30 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 the mechanical properties of the obtained laser welding member tend to be improved. By setting the concentration to 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 obtained by dissolving 0.5 g of polyethylene terephthalate resin in 25 mL of benzyl alcohol and titrating 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 conventionally known arbitrary method such as a method for adjusting polymerization conditions such as a raw material charge ratio during polymerization, a polymerization temperature, a pressure reduction method, a method for reacting a terminal blocking agent, etc. Just do it.

  (A) The thermoplastic polyester resin preferably contains a polybutylene terephthalate resin and a polycarbonate resin. By containing a specific amount of the polycarbonate resin, the laser weldability is easily improved, which is preferable.

[Polycarbonate resin]
The polycarbonate resin is an optionally branched thermoplastic polymer or copolymer obtained by reacting a dihydroxy compound or a small amount thereof 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 melting method (transesterification method) can be used. From the viewpoint of laser permeability and laser weldability, it is preferable.

  The starting dihydroxy compound is substantially free of bromine atoms and is preferably an aromatic dihydroxy compound. Specifically, 2,2-bis (4-hydroxyphenyl) propane (ie, bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxy Diphenyl etc. are mentioned, Preferably bisphenol A is mentioned. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

  As the polycarbonate resin, among the above-mentioned, aromatic polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other aromatic dihydroxy Aromatic polycarbonate copolymers derived from the 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. Furthermore, you may mix and use 2 or more types of the polycarbonate resin mentioned above.

  In order to adjust the molecular weight of the polycarbonate resin, a monovalent aromatic hydroxy compound may be used. For example, m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long chain And 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. When a material having a viscosity average molecular weight lower than 5,000 is used, the obtained welding member tends to have a low mechanical strength. On the other hand, if it is higher than 30,000, the fluidity of the resin material may be deteriorated and the moldability may be deteriorated or the laser weldability may be deteriorated. The viscosity average molecular weight of the polycarbonate resin is a viscosity average molecular weight [Mv] converted from a solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent.

  The ratio (Mw / Mn) of polystyrene-converted mass average molecular weight Mw and number average molecular weight Mn measured by gel permeation chromatography (GPC) of the polycarbonate resin is preferably 2 to 5, 2.5 ~ 4 is more preferred. When Mw / Mn is too small, the fluidity in the molten state increases and the moldability tends to decrease. On the other hand, if Mw / Mn is excessively large, the melt viscosity tends to increase and molding becomes difficult.

  The amount of terminal hydroxy groups of the polycarbonate resin is preferably 100 ppm by mass or more, more preferably 200 ppm by mass or more, and still more preferably 300 ppm by mass from the viewpoints of thermal stability, hydrolysis stability, color tone, and the like. Above, particularly preferably 400 mass ppm or more, most preferably 500 mass ppm or more. However, it is usually 1,500 mass ppm or less, preferably 1,300 mass ppm or less, more preferably 1,200 mass ppm or less, particularly preferably 1,100 mass ppm or less, most preferably 1,000 mass ppm or less. . When the amount of terminal hydroxy groups of the polycarbonate resin is too small, the laser transmittance tends to be lowered, and the initial hue at the time of molding may be deteriorated. When the amount of terminal hydroxy groups is excessively large, the residence 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 transmittance and laser weldability.

  In the melt polymerization method, an ester exchange reaction between an aromatic dihydroxy compound and a carbonic acid diester is performed.

The aromatic dihydroxy compound is as described above.
On the other hand, examples of the carbonic acid diester include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-tert-butyl carbonate; diphenyl carbonate; substituted diphenyl carbonate such as ditolyl carbonate; Among these, diaryl carbonate is preferable, and diphenyl carbonate is particularly preferable. In addition, 1 type may be used for carbonic acid diester, and it may use 2 or more types together by arbitrary combinations and a 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 an equimolar amount or more of the carbonic acid diester with respect to 1 mol of the dihydroxy compound. More preferably, it is used. The upper limit is usually 1.30 mol or less. By setting it as such a range, the amount of terminal hydroxy groups can be adjusted to a suitable range.

  In the polycarbonate resin, the amount of terminal hydroxy groups tends to have a great influence on thermal stability, hydrolysis stability, color tone and the like. For this reason, you may adjust the amount of terminal hydroxy groups as needed by arbitrary well-known methods. In the transesterification reaction, a polycarbonate resin in which the amount of terminal hydroxy groups is adjusted can be usually obtained by adjusting the mixing ratio of the carbonic acid diester and the dihydroxy compound, the degree of vacuum during the transesterification reaction, and the like. In addition, the molecular weight of the polycarbonate resin usually obtained can also be adjusted by this operation.

When adjusting the amount of terminal hydroxy groups by adjusting the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound, the mixing ratio is as described above.
Further, as a more aggressive adjustment method, there may be mentioned a method in which a terminal terminator is mixed separately during the reaction. Examples of the terminal terminator at this time include monohydric phenols, monovalent carboxylic acids, carbonic acid diesters, and the like. In addition, 1 type may be used for a terminal terminator and it may use 2 or more types together by arbitrary combinations and a ratio.

  When producing a polycarbonate resin by the melt polymerization method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Among these, it is preferable to use an alkali metal compound and / or an alkaline earth metal compound. In addition, auxiliary compounds such as basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds may be used in combination. In addition, 1 type may be used for a transesterification catalyst and it may use 2 or more types together by arbitrary combinations and a 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, a melt polycondensation reaction may be performed under the conditions in 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. In the case of a batch system, the order of mixing the reaction substrate, reaction medium, catalyst, additive, etc. is arbitrary as long as the desired polycarbonate resin is obtained, and an appropriate order may be set arbitrarily. However, in view of the stability of the polycarbonate resin and the resin material containing the polycarbonate resin, the melt polycondensation reaction is preferably carried out continuously.

In the melt polymerization method, a catalyst deactivator may be used as necessary. As the catalyst deactivator, a compound that neutralizes the transesterification catalyst can be arbitrarily used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. In addition, a catalyst deactivator may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the catalyst deactivator used is usually 0.5 equivalents or more, preferably 1 equivalent or more, and usually 10 equivalents or less, relative to the alkali metal or alkaline earth metal contained in the transesterification catalyst. Preferably it is 5 equivalents or less. Furthermore, it is 1 mass ppm or more normally with respect to polycarbonate resin, and is 100 mass ppm or less normally, Preferably it is 20 mass ppm or less.

  (A) When the thermoplastic polyester resin contains a polybutylene terephthalate resin and a polycarbonate resin, the content of the polybutylene terephthalate resin and the polycarbonate resin is preferably 10 to 10 parts by weight. It is 50 mass%, More preferably, it is 15-45 mass%, More preferably, it is 20-40 mass%. If the content of the polycarbonate resin is less than 10% by mass, the laser welding strength tends to decrease, and if it exceeds 50% by mass, the moldability may be remarkably decreased.

[Aromatic vinyl resin]
(A) The thermoplastic polyester resin also preferably contains a polybutylene terephthalate resin and an aromatic vinyl resin.
The aromatic vinyl resin is a polymer mainly composed of an aromatic vinyl compound. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, and vinylxylene. Styrene is preferred. A typical example of the aromatic vinyl resin is polystyrene (PS).
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 in which styrene and acrylonitrile are co-polymerized.

As the aromatic vinyl resin, a rubber-containing aromatic vinyl resin obtained by copolymerizing or blending rubber components 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. An acrylic rubber component can be used as the rubber component, but it is not preferable because it is poor in terms of 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 the entire aromatic vinyl resin segment. 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 more 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, bleeding out is observed in the molded product, or decomposition gas is generated at the time of molding, and it is difficult to obtain sufficient weld strength. If the molecular weight is greater than 500,000, sufficient fluidity is 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. Preferably, it is 1-20 g / 10min. If the MFR is less than 0.1 g / 10 min, the compatibility with the polybutylene terephthalate resin becomes insufficient, and the appearance of delamination may occur during injection molding. On the other hand, if the MFR is larger than 50 g / 10 min, the impact resistance is greatly lowered, which is not preferable.
In particular, in the case of polystyrene, the MFR is preferably 1 to 50 g / 10 minutes, more preferably 3 to 35 g / 10 minutes, and further preferably 5 to 20 g / 10 minutes. In the case of 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 1 to 20 g / 10 minutes. Further preferred.

  (A) When the thermoplastic polyester resin contains a polybutylene terephthalate resin and an aromatic vinyl resin, the content of the aromatic vinyl resin is 100% by mass of the total of the polybutylene terephthalate resin and the aromatic vinyl resin. The resin is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and still more preferably 20 to 40% by mass. If the content of the aromatic vinyl resin is less than 10% by mass, the laser welding strength tends to decrease, and if it exceeds 50% by mass, the heat resistance and heat discoloration may be decreased.

In particular, in the present invention, it is preferable from the viewpoint of laser weldability that (A) the thermoplastic polyester resin contains polybutylene terephthalate resin, polystyrene and / or butadiene rubber-containing polystyrene and polycarbonate resin.
The polycarbonate resin is as described above.
Polystyrene is a copolymer of styrene homopolymer or other aromatic vinyl monomer such as α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene, etc. within a range of, for example, 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, or more. Preferably it is 5-30 mass%, More preferably, it is 5-20 mass%. High impact polystyrene (HIPS) is particularly preferable as the butadiene rubber-containing polystyrene.
Among polystyrene or butadiene rubber-containing polystyrene, butadiene rubber-containing polystyrene is preferable, and high impact polystyrene (HIPS) is particularly preferable.

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

(A) When the thermoplastic polyester resin contains a polybutylene terephthalate resin, polystyrene and / or butadiene rubber-containing polystyrene and a polycarbonate resin, the crystallization temperature (Tc) of the resulting resin composition is preferably 190 ° C. or lower. . That is, laser transmissivity can be further improved by appropriately suppressing the transesterification reaction between the polybutylene terephthalate resin and the polycarbonate resin and appropriately reducing the crystallization temperature. The crystallization temperature (Tc) is more preferably 188 ° C. or less, further preferably 185 ° C. or less, particularly preferably 182 ° C. or less, and most preferably 180 ° C. or less. Moreover, the minimum is 160 degreeC normally, Preferably it is 165 degreeC or more.
The crystallization temperature (Tc) was raised at a heating rate of 20 ° C./min from 30 to 300 ° C. under a nitrogen atmosphere using a differential scanning calorimetry (DSC) machine and held at 300 ° C. for 3 minutes. Thereafter, it is measured as a peak top temperature of an exothermic peak observed when the temperature is lowered at a temperature lowering rate of 20 ° C./min.

(A) Content when a thermoplastic polyester resin contains polybutylene terephthalate resin, polystyrene and / or butadiene rubber containing polystyrene, and polycarbonate resin is as follows.
The content of the polybutylene terephthalate resin is preferably 30 to 90% by mass, and 40 to 80% by mass based on a total of 100% by mass of the polybutylene terephthalate resin, polystyrene and / or butadiene rubber-containing polystyrene and polycarbonate resin. More preferred is 50 to 70% by mass. When the content is less than 30% by mass, the heat resistance may be lowered, and when it exceeds 90% by mass, the transmittance tends to be lowered, which is not preferable.

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

  The total content of polystyrene and / or butadiene rubber-containing polystyrene and polycarbonate resin is 10 to 55% by mass in a total of 100% by mass of polybutylene terephthalate 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. By setting it as such content, it becomes the tendency which is excellent in the balance of heat resistance and laser transmittance, and is preferable.

  Furthermore, the content ratio of the polystyrene and / or butadiene rubber-containing polystyrene and the polycarbonate resin component is preferably 5: 1 to 1: 5, more preferably 4: 1 to 1: 4, in terms of mass ratio. By setting it as such a content rate, it exists in the tendency which is excellent in the balance of heat resistance and a laser transmittance, and is preferable.

[(B) Glass fiber and (C) Glass beads]
The resin composition of the present invention contains (B) glass fibers having an average fiber diameter of more than 15 μm and / or (C) glass beads having an average particle diameter of 25 μm or more.

(B) Glass fiber The (B) glass fiber used by this invention uses the thing of a large diameter whose diameter is 15 micrometers or more compared with the glass fiber marketed conventionally. By using such large-diameter glass fibers, the number of glass fibers to be blended can be reduced, and even in the resin composition, the internal scattering of the laser light is greatly reduced and the transmittance is increased, thereby improving the laser weldability. . Moreover, since the number of the glass fibers to mix | blend can be decreased, the surface appearance defect by the float on the molded article surface of a glass fiber, etc. and a weather resistance fall can be suppressed.
The diameter of the glass fiber is preferably 16 μm or more, more preferably 16.5 μm or more, preferably 25 μm or less, more preferably 22 μm or less, and even more preferably 20 μm or less.

  (B) The number average fiber length of the glass fibers is preferably 1 mm or more and 10 mm or less, more preferably 1.5 to 6 mm, and further preferably 2 to 5 mm. When the number average fiber length exceeds 10 mm, the glass fibers are likely to fall off from the surface of the molded product, and the productivity tends to be lowered. If the number average fiber length is less than 1 mm, the glass fiber has a small aspect ratio, and therefore mechanical strength is likely to be insufficiently improved.

  (B) The shape of the fiber cross section of the glass fiber is not limited, but it is preferably circular, and specifically, the cross section of the fiber cross section (major axis / minor axis) is 1 or more and less than 1.5. It is preferably a substantially circular glass fiber. The aspect ratio is more preferably 1 to 1.4, still more preferably 1 to 1.2, and particularly preferably 1 to 1.1.

  (B) As a glass fiber, if it is normally used for a thermoplastic resin, A glass, E glass, S glass, C glass, D glass, the alkali-resistant glass composition containing a zirconia component, and a chopped strand Any known glass fiber can be used regardless of the form of the glass fiber at the time of compounding, such as roving glass, a thermoplastic resin and glass fiber (long fiber) masterbatch.

  (B) Glass fiber can be produced by pulverizing glass fiber strands, for example, with a hammer mill or ball mill, according to any conventionally known method.

  (B) Glass fiber (A) In order to improve adhesion with thermoplastic polyester resin, and for the purpose of improving mechanical properties, durability, heat and humidity resistance, hydrolysis resistance, heat shock resistance, Surface treatment can be performed with a silane coupling agent or the like. Examples of the coupling agent that can be used for the surface treatment include silane-based, titanate-based, aluminum-based, chromium-based, zirconium-based, and borane-based. Among these, silane-based coupling agents are preferable.

  As the silane coupling agent, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, vinyl-tris (2-methoxyethoxy) silane, γ- Methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ -Mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, etc., among which γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (Aminoethyl) -γ-aminopropyl Use or combination of one or more coupling agents selected from trimethoxysilane are particularly preferred.

In addition, the glass fiber (B) used in the present invention is also preferably used as a chopped strand (chopped glass fiber) obtained by cutting a number of these fibers into a predetermined length. The glass fiber is preferably blended with a sizing agent. In addition to the advantage of improving the production stability of the resin composition of the present invention by blending the sizing agent, good mechanical properties can be obtained.
The sizing agent is not particularly limited, and examples thereof include urethane-based, epoxy-based, acrylic-based sizing agents. Among them, the glass fiber sizing agent used in the present invention is more preferably a urethane or epoxy sizing agent, and more preferably an epoxy sizing agent. Preferred examples of the epoxy sizing agent include novolak type epoxy resins, bisphenol A type epoxy resins, and the like, and among them, bisphenol A type epoxy resins are preferable. When the bisphenol A type epoxy resin is used, the interfacial adhesion between the (B) glass fiber and the (A) thermoplastic polyester resin is not too strong and is appropriate, and (A) the crystallization of the thermoplastic polyester resin is difficult to proceed. Therefore, it is considered that the resulting transmittance is likely to improve.

  Although there is no restriction | limiting in particular also about the cut length of a chopped strand (chopped glass fiber), Usually, 1-10 mm, Preferably it is 1.5-6 mm, More preferably, it is 2-5 mm.

(C) Glass beads (C) Glass beads used in the present invention have an average particle size of 25 μm or more. By containing such large glass beads, the amount of glass beads to be blended can be reduced, so that laser welding is improved by greatly reducing internal scattering of laser light and increasing transmittance even in the resin composition. Further, since the glass beads can be reduced, it is possible to suppress surface appearance defects and deterioration of weather resistance due to floating of the glass beads on the surface of the molded product.

  (C) The average particle diameter of the glass beads is preferably 30 μm or more, more preferably 35 μm or more, especially 40 μm or more, especially 45 μm or more, particularly preferably 50 μm or more, and preferably 100 μm or less, more preferably It is preferably 90 μm or less, more preferably 80 μm or less, particularly preferably 75 μm or less, and particularly preferably 70 μm or less.

The (C) glass beads used in the present invention may be hollow beads, hollow glass beads, glass balloons, or the like. (C) The glass beads are preferably closer to the true sphere, and the sphericity of the (C) glass beads is preferably 1 to 1.7, particularly 1 to 1.5, and particularly preferably 1 to 1.2.
In addition, said average particle diameter and sphericity can be measured using a particle size distribution measuring machine. The average particle diameter refers to D ₅₀ (median diameter of particle diameter distribution) measured by a laser diffraction method.

  (C) The glass composition of glass beads is preferably composed of a glass composition such as A glass, C glass, E glass, S glass, and D glass, particularly E glass that is non-alkali glass.

  Such (C) glass beads may be surface-treated with a surface treatment agent such as a coupling agent, and the adhesion to the (A) thermoplastic polyester resin component is moderately enhanced by the surface treatment. In addition, the mechanical properties, durability, wet heat resistance, hydrolysis resistance, and heat shock resistance of the resin composition are easily improved.

  (C) Examples of coupling agents that can be used for the surface treatment of glass beads include silane, titanate, aluminum, chromium, zirconium, or borane. Among these, silane coupling agents Is preferred.

  Examples of the silane coupling agent include those described above. Among them, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) are exemplified. The use or combination of one or more coupling agents selected from) -γ-aminopropyltrimethoxysilane is particularly preferred.

  The method for treating (C) glass beads using these coupling agents is not particularly limited, and conventionally used methods such as dip coating, roller coating, spray coating, flow coating, spray coating, etc. Can be used.

  The content of (B) glass fiber or (C) glass beads is 10 to 100 parts by mass with respect to 100 parts by mass of (A) thermoplastic polyester resin. Preferably it is 20 parts by mass or more, more preferably 25 parts by mass or more, further preferably 30 parts by mass or more, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and still more preferably 60 parts by mass. It is below mass parts. When the content is less than 10 parts by mass, the reinforcing effect is small, and mechanical properties such as rigidity and impact resistance are lowered. Conversely, when the content exceeds 100 parts by mass, fluidity, laser transmittance, laser weldability, molded products Appearance and weather resistance deteriorate. In addition, it is preferable that the total content when (B) glass fibers and (C) glass beads are contained together is also in the above range.

[Stabilizer]
The resin composition of the present invention preferably contains a stabilizer.
Examples of the stabilizer include various stabilizers such as a phosphorus stabilizer, a sulfur stabilizer, and a phenol stabilizer. Particularly preferred are phosphorus stabilizers and phenolic stabilizers.

  It is preferable that content of a stabilizer is 0.001-2 mass parts with respect to 100 mass parts of (A) thermoplastic polyester resin. When the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in the thermal stability and compatibility of the welding member, and molecular weight reduction and hue deterioration during molding are likely to occur. When it exceeds, it will become excess amount and there exists a tendency for generation | occurrence | production of silver and a hue deterioration to occur further easily. The content of the stabilizer is more preferably 0.01 to 1 part by mass, and still more preferably 0.05 to 0.5 part by mass.

Examples of phosphorus stabilizers include phosphorous acid, phosphoric acid, phosphite esters, and phosphate esters. Among them, organic phosphate compounds, organic phosphite compounds, or organic phosphonite compounds are preferable, and organic phosphate compounds are particularly preferable. .
As the organic phosphate compound, a compound represented by the following general formula (1) is preferable.
(In General Formula (1), R ¹ represents an alkyl group or an aryl group. N represents an integer of 0 to 2. When n is 0, two R ^{1 s} may be the same or different, When n is 1, two R ¹ may be the same or different.)

In the general formula (1), R ¹ represents an alkyl group or an aryl group. R ¹ is preferably 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 and usually 30 or less carbon atoms. , R ¹ is preferably an alkyl group rather than an aryl group. In addition, when two or more R ¹ exists, R ¹ may be the same or different from each other.

More preferred is a long-chain alkyl acid phosphate compound in which R ¹ has 8 to 30 carbon atoms than the phosphorus system represented by the general formula (1). 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, A hexadecyl group, an octadecyl group, an eicosyl group, a triacontyl group, etc. are 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, nonyl phenyl acid phosphate 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.

  Among these, octadecyl acid phosphate is preferable, and this is marketed under the trade name “Adeka Stab AX-71” manufactured by ADEKA.

  It is preferable that content of the phosphorus stabilizer represented by the said General formula (1) is 0.001-1 mass part with respect to 100 mass parts of (A) thermoplastic polyester resins. When the content is less than 0.001 part by mass, it is difficult to expect improvement in the thermal stability and compatibility of the welding member, and when the amount exceeds 1 part by mass, a decrease in molecular weight and a deterioration in hue are likely to occur. There is a tendency that the amount of silver becomes excessive and the occurrence of silver and hue deterioration are more likely to occur, and at the same time, the laser transmittance and laser weldability tend to decrease. A more preferable content is 0.01 to 0.6 parts by mass, and still more preferably 0.05 to 0.4 parts by mass.

  By blending the phosphorus-based stabilizer represented by the above general formula, particularly when (A) the thermoplastic polyester resin contains a polybutylene terephthalate resin and a polycarbonate resin, the transesterification reaction of both will be moderately suppressed, The crystallization temperature of the resin composition tends to be 190 ° C. or less, and thereby the laser light permeability and laser weldability are more likely to be improved.

  As the phenol stabilizer, a hindered phenol stabilizer is preferable. For example, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6 -Diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis ( 1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphoate, 3,3 ′, 3 ″ 5,5 ′, 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-) , 5-di -tert- pentylphenyl) ethyl] -4,6-di -tert- pentylphenyl acrylate.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate preferable. As such a phenolic antioxidant, specifically, for example, “Irganox 1010”, “Irganox 1076” manufactured by BASF (trade name, the same applies hereinafter), “Adeka Stub AO-50” manufactured by ADEKA, "ADK STAB AO-60" etc. are mentioned.
In addition, 1 type may be contained for the hindered phenol type stabilizer, and 2 or more types may be contained in arbitrary combinations and ratios.

It is preferable that content of a phenol type stabilizer is 0.01-1 mass part with respect to 100 mass parts of (A) thermoplastic polyester resins. If the content is less than 0.01 parts by mass, the thermal stability tends to be reduced, and if it exceeds 1 part by mass, the laser transmittance may be reduced. More preferable content is 0.05-0.8 mass part, More preferably, it is 0.1-0.6 mass part.
In the present invention, it is preferable to use a phosphorus-based stabilizer represented by the general formula (1) and a phenol-based stabilizer in combination from the viewpoints of retention characteristics, heat resistance, laser transmittance, and laser weldability.

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

  Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax. Among them, those having a mass average molecular weight of 700 to 10,000, more preferably 900 to 8,000 are preferable. In addition, modified polyolefin compounds in which a hydroxyl group, a carboxyl group, a hydroxyl group, an epoxy group, or the like is introduced into the side chain are also particularly preferable.

  Examples of the fatty acid ester compounds include fatty acid esters such as glycerin fatty acid esters, sorbitan fatty acid esters, pentaerythritol fatty acid esters, and partially saponified products thereof. Among them, carbon atoms are 11 to 28, preferably carbon atoms. Mono- or di-fatty acid esters composed of fatty acids of several 17 to 21 are preferred. Specific examples include glycerol monostearate, glycerol monobehenate, glycerol dibehenate, glycerol-12-hydroxy monostearate, sorbitan monobehenate, pentaerythritol distearate, pentaerythritol tetrastearate and the like.

  Moreover, as a silicone type compound, the compound modified | denatured from points, such as compatibility with (A) thermoplastic polyester resin, is preferable. Examples of the modified silicone oil include silicone oil in which an organic group is introduced into the side chain of polysiloxane, silicone oil in which an organic group is introduced into both ends and / or one end of polysiloxane, and the like. Examples of the organic group to be introduced include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacryl group, a mercapto group, and a phenol group, and preferably an epoxy group. As the modified silicone oil, a silicone oil in which an epoxy group is introduced into the side chain of polysiloxane is particularly preferable.

  It is preferable that content of a mold release agent is 0.05-2 mass parts with respect to 100 mass parts of (A) thermoplastic polyester resin. If the amount is less than 0.05 parts by mass, the surface property tends to decrease due to defective mold release at the time of melt molding. On the other hand, if it exceeds 2 parts by mass, the kneading workability of the resin composition decreases, and molding is also performed. The surface of the product 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 parts by mass.

[Other ingredients]
The resin composition of the present invention may contain various additives other than those described above as long as the effects of the present invention are not significantly impaired. Examples of such additives include flame retardants, flame retardant aids, ultraviolet absorbers, antistatic agents, antifogging agents, lubricants, antiblocking agents, plasticizers, dispersants, and antibacterial agents.

  In addition, the resin composition of the present invention can contain (A) a thermoplastic resin other than the thermoplastic polyester resin as long as the effects of the present invention are not impaired. Specific examples of other thermoplastic resins include polyamide resins, polysulfone resins, polyether sulfone resins, polyetherimide resins, polyether ketone resins, and polyphenylene ether resins.

[Method for Producing Resin Composition]
As a manufacturing method of the resin composition of this invention, it can carry out in accordance with the conventional method of resin composition preparation. Usually, the components and various additives added as desired are mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Moreover, it is also possible to prepare the resin composition of the present invention by mixing each component in advance or by mixing only a part of the components in advance and supplying them to an extruder using a feeder and melt-kneading them. Further, a master batch may be prepared by melting and kneading a part of a thermoplastic resin and a part of another component, and then the other other ingredients may be blended and melt-kneading. (B) Glass fiber and (C) glass beads are preferably supplied from a side feeder in the middle of the cylinder of the extruder in order to suppress crushing during melt-kneading.

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

[Manufacture of molded products for laser welding]
The manufacturing method of the laser-welded molded body is not particularly limited, and a molding method generally employed for the thermoplastic polyester resin composition can be arbitrarily employed. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include a blow molding method. Of these, injection molding is preferred. As the injection molding method, for example, a high-speed injection molding method, an injection compression molding method, or the like can be used.

  The injection molding conditions are not particularly limited, but the injection speed is preferably 10 to 500 mm / sec, more preferably 30 to 400 mm / sec, still more preferably 50 to 300 mm / sec, and particularly preferably 80 to 200 mm / sec. preferable. The resin temperature may be appropriately adjusted depending on the type of (A) thermoplastic polyester resin to be used. For example, in the case of a polybutylene terephthalate resin, 250 to 280 ° C is preferable, and 255 to 275 ° C is more preferable. 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 Preferably, 25-100 cm < ³ > / sec is more preferable, and 50-90 cm < ³ > / sec is especially preferable. By making the injection rate in such a range, it becomes easier to increase the laser transmittance of the anti-gate side part of the molded product, and by adjusting the gate position, the transmittance of the welded part in the molded product can be increased. Can do. In injection molding, the volume of the resin composition injected in one injection is controlled by adjusting the injection volume of the resin material per unit time and the time required for injection, but the material capacity of the resin composition per unit time Is the injection rate (unit: cm ³ / sec).

Moreover, it is preferable to perform injection molding under the condition that the surface progression coefficient defined as a value obtained by dividing the injection rate by the thickness of the mold cavity into which the resin composition is injected 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 non-gate side portion of the molded product, and by adjusting the gate position, the transmittance of the welded portion in the molded product is further increased. be able to. The preferred range of surface progression coefficient 200~1100cm ³ / sec · cm, more preferably 250~1000cm ³ / sec · cm, more preferably 300~950cm ³ / sec · cm, particularly preferably 400~900cm ³ / sec · cm.

The resin composition for laser welding according to the present invention preferably has a crystallization temperature (Tc) of 190 ° C. or lower. When the crystallization temperature (Tc) is 190 ° C. or lower, the laser transmittance of the resin composition tends to increase. The crystallization temperature (Tc) is more preferably 188 ° C. or less, further preferably 185 ° C. or less, particularly preferably 182 ° C. or less, and most preferably 180 ° C. or less. Moreover, the minimum is 160 degreeC normally, Preferably it is 165 degreeC or more.
The method for measuring the crystallization temperature (Tc) is as described in the examples.

  The obtained molded body is subjected to laser welding. There is no restriction | limiting in particular in the method of laser welding, It can carry out by a normal method. The molded product (first member) obtained by the laser welding resin composition of the present invention is placed on the transmission side, and the counterpart resin molded product (second member, adherend) is brought into contact (especially at least the welded portion). Surface contact) and irradiating with laser light, the two types of molded bodies are welded and integrated into one molded product.

  In the present invention, it is preferable from the viewpoint of laser light transmission that laser welding is performed using a portion at a position 15 mm or more away from the gate of the injection mold as a welding portion. It is preferable that at least a part of the laser welding portion is 15 mm or more away from the gate, but 30% or more of the total area of the laser welding portion is more preferably 15 mm or more away from the gate, more preferably 50% or more. 70% or more is particularly preferable, and it is most preferable that all the parts to be laser-welded are separated from the gate by 15 mm or more.

When the thermoplastic polyester resin composition of the present invention is injection-molded, the variation in laser transmittance is large depending on the part (position) of the molded body, the transmittance is low at a part near the gate position, and the distance from the gate is long. It has been clarified by the inventor's examination that excellent transmittance is exhibited.
Further, this transmittance is affected by the composition of the thermoplastic polyester resin composition used, the thickness of the laser welding part, the injection molding conditions, etc., but in the present invention, the composition of the thermoplastic polyester resin composition, the laser welding part Regardless of the thickness, injection molding conditions, etc., the laser transmittance is improved to 30% or more by laser beam with a wavelength of 940 nm at the laser welding site, thereby improving the laser workability and enabling strong laser welding It is preferable from the point which becomes.

  There is no limitation on the shape of the molded body to be subjected to laser welding, preferably the distance from the gate of the injection mold is 15 mm or more, preferably 25 mm or more, more preferably 30 mm or more, further preferably 40 mm or more, particularly preferably. As long as it has a welding part at a position 45 mm or more, most preferably 50 mm or more away, the entire shape may be any. Usually, the welded part is joined to a mating material (other resin or a molded body of the same resin) for laser welding, so the welded part has a shape (for example, a plate shape) having at least a contact surface (such as a flat surface). is there. The thickness of the laser beam transmission site 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 about 0.5 to 1 mm.

  The laser welding part preferably has a transmittance of 25% or more in a laser beam having a wavelength of 940 nm, more preferably 30% or more, further 35% or more, particularly 40% or more, especially 45% or more, particularly It is preferably 50% or more, and most preferably 55% or more.

Since the transmittance becomes higher as the thickness of the molded body is thinner, the composition of the thermoplastic polyester resin composition used, the thickness of the molded body, the distance from the gate of the injection mold and the injection are used in order to obtain the above-mentioned preferable transmittance. The molding conditions such as the speed, injection rate, surface progression coefficient, resin temperature, and mold temperature may be adjusted as appropriate so that the laser welding portion has a higher transmittance.
In addition, the transmittance | permeability in this invention means the transmittance | permeability in the laser beam of wavelength 940nm.

  The crystallization temperature (Tc) at the site where laser welding is performed is preferably 190 ° C. or lower, more preferably 188 ° C. or lower, more preferably 185 ° C. or lower, particularly preferably 182 ° C. or lower, and most preferably 180 ° C. or lower. . Moreover, the minimum is 160 degreeC normally, Preferably it is 165 degreeC or more. The method for measuring the crystallization temperature (Tc) is as described above.

  The welded part of the injection-molded welded molding is brought into surface contact or butt contact with the counterpart member containing the laser light absorber, and usually the laser beam is irradiated from the side of the welding member having a high transmittance. By doing so, the interface between the two can be at least partially melted and cooled to be integrated into one welded body.

  The member on the other side containing the laser light absorber is not particularly limited as long as it is a member made of a thermoplastic resin composition that can absorb laser light and is melted by absorbing the laser light. . Specifically, a member made of a resin composition that usually contains carbon black or a laser-absorbing dye in order to be able to absorb laser light is exemplified. Although content of absorbers, such as carbon black, is not specifically limited, For example, it is preferable to make it contain 0.2-1 mass% with respect to a resin composition.

  Preferred examples of the laser light absorbing dye include nigrosine, aniline black, phthalocyanine, naphthalocyanine, porphyrin, perylene, quaterylene, azo dye, anthraquinone, squaric acid derivative and immonium.

  Of these, nigrosine is particularly preferred. Nigrosine is C.I. I. SOLVENT BLACK 5 and C.I. I. It is a black azine-based condensation mixture as described in COLOR INDEX as SOLVEN BLACK 7. Examples of commercially available nigrosine include “NUBIAN (registered trademark) BLACK” (trade name, manufactured by Orient Chemical Industries).

  The content of the laser light absorbing dye is 0.001 to 0.2 parts by mass, preferably 0.003 to 0.1 parts by mass, and more preferably 0.005 to 0 parts per 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 the members are the thermoplastic polyester resin composition described above, and the counterpart material contains carbon black or a laser light absorbing dye. Since such a member has the same composition except for the presence or absence of carbon black or a laser light absorbing dye, the welded members are easily compatible with each other and are more firmly fixed.

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

  The shape, size, thickness, etc. of the welded body integrated by laser welding are arbitrary, and the uses of the welded body include electrical parts for transportation equipment such as automobiles, electrical and electronic equipment parts, parts for industrial machinery, etc. It is particularly suitable for consumer parts.

Hereinafter, the present invention will be described more specifically with reference to examples. However, 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.

(Examples 1-3, Comparative Examples 1-4)
[Manufacture of laser transmission side molded body]
Each component other than the glass fibers and glass beads described in Table 1 above was blended in the amounts (all parts by mass) described in Table 2 below, and this was blended into a 30 mm vent type twin screw extruder (Nippon Steel Works). Glass fiber and glass beads are supplied from the 7th side feeder from the hopper using an extruder “TEX30α”), the extruder barrel set temperature C1 to C15 is 260 ° C., the die is 250 ° C., the screw speed is 200 rpm, and the discharge is 40 kg. The mixture was kneaded under the conditions of / hour and extruded into a strand shape to obtain resin composition pellets.
The obtained resin composition pellets were dried at 120 ° C. for 5 hours, and then, with an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., model: SE50), the cylinder temperature was 250 ° C., the mold temperature was 80 ° C., and the injection speed was 33 mm. / Sec, injection rate 59 cm ³ / sec, and surface progression coefficient 393 cm ³ / sec · cm were injection molded to produce ASTM No. 4 dumbbell pieces (thickness 1.5 mm) for laser welding evaluation shown in FIG. In addition, 1 in FIG. 1 shows the gate position at the time of injection molding, 2 shows the laser irradiation location in the laser welding evaluation mentioned later.

(1) Transmittance For the laser welded portion (see FIG. 1) of the anti-gate portion of the ASTM No. 4 dumbbell piece obtained above, using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation) at a wavelength of 940 nm The transmittance (unit:%) was measured. In addition, the distance from the gate of the laser welding part was 100 mm.

(2) Crystallization temperature (Tc)
The crystallization temperature (Tc) of the resin composition was increased from 30 to 300 ° C. at a rate of temperature increase of 20 ° C./min using a differential scanning calorimetry (DSC) machine (“Pyris Diamond” manufactured by Perkin Elmer). After maintaining at 300 ° C. for 3 minutes, the peak top temperature of the exothermic peak observed when the temperature was decreased at a temperature decrease rate of 20 ° C./min was measured as the crystallization temperature (unit: ° C.).

(3) Laser welding evaluation The following laser welding test was conducted with the ASTM No. 4 dumbbell piece obtained above as the transmission side.
As a member for laser absorption of the counterpart material, an ASTM No. 4 dumbbell piece obtained by molding a resin composition pellet obtained from each of the following components in the same manner as the above-described transmission material was used. In addition, the distance from the gate of the laser welding part was 100 mm.
Polybutylene terephthalate resin Novaduran (registered trademark, manufactured by Mitsubishi Engineering Plastics) 5010: 67.4% by mass
Glass fiber T-187 (manufactured by Nippon Electric Glass Co., Ltd., fiber diameter 13 μm): 30% by mass
-Stabilizer Adeka Sizer EP-17 (manufactured by ADEKA): 0.4% by mass
-Stabilizer ADK STAB AO-60 (manufactured by ADEKA): 0.2% by mass
Carbon black mass batch (80% by mass of polybutylene terephthalate resin Novaduran 5008, 20% by mass of carbon black): 2% by mass

  The ASTM No. 4 dumbbell piece (thickness: 1.5 mm) was superposed on the laser absorbing member as a transmission side member, and a laser was irradiated on the laser irradiation portion 2 of the dumbbell piece.

Laser welding uses a fine device laser device (laser 140W fiber core diameter 0.6 mm), laser wavelength: 940 nm, laser scan speed: 40 mm / second, scan length: 10 mm, laser output: 50 W, pressure: 0 The distance between the laser head and the test piece 2 was 79.7 mm.
I went there.

  Using the welded body integrated by welding, the laser welding strength was measured. The welding strength is measured by using a tensile tester (Instron “5544”), and welding and integrating the transmission side member and the laser absorbing member with both ends in the long axis direction clamped. Evaluation was performed by pinching and 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.

(4) Appearance After the resin composition pellets obtained above were dried at 120 ° C. for 5 hours, the cylinder temperature was 250 ° C. and the mold temperature was used by using an injection molding machine (NEX80-9E manufactured by Nissei Plastic Industry Co., Ltd.). A molded product having a size of 100 mm × 100 mm × 3 mmt was injection molded under the conditions of 80 ° C. and cooling time of 15 seconds. The obtained molded product was visually observed and the appearance was evaluated according to the following criteria.
◎: The reinforcing filler does not float and is excellent in appearance. ○: The reinforcing filler does not stand out and is not problematic as an actual product. △: The reinforcing filler floats partially.

(5) Weather resistance test For a molded product having a size of 100 mm x 100 mm x 3 mmt obtained by the same method as in (4) above, a weather resistance treatment was performed under the following conditions (according to ASTM G151) using a xenon weather tester. It was.
Equipment used: Atlas Ci4000
Filter / Inner; Quartz Filter / Outer; Type S borosilicate Black panel temperature; 63 ° C
Irradiance: 0.35 W / m ² (at 340 nm)
Processing time: 3000 hours Rain (102 spectral irradiation + 18 dispersed water for 1 cycle)
The appearance of the molded product after the above treatment was visually observed, and the weather resistance was evaluated according to the following criteria.
○: Lifting of reinforcing filler is not noticeable and is at a level where there is no problem as an actual product. Δ: Lifting of reinforcing filler is partially conspicuous. ×: Lifting of reinforcing filler is conspicuous as a whole. 2.

From the results of Table 2, it can be seen that the thermoplastic polyester resin composition of the present invention is excellent in balance in all of laser transmittance, laser weldability, appearance of molded product and weather resistance (Examples 1 to 3). . In particular, when a polybutylene terephthalate homopolymer and a modified polybutylene terephthalate resin are used in combination as a thermoplastic polyester resin, it can be seen that laser transmittance and laser weldability are more excellent (Example 3).
On the other hand, in Comparative Example 1 using glass fibers having an average fiber diameter of 15 μm or less, the laser transmittance is lowered and sufficient laser welding strength is not obtained. Moreover, it turns out that the external appearance after a molded article appearance and a weathering process also falls, and a weather resistance is also inferior.
Although Comparative Example 4 using glass fibers having a flat fiber cross section has a cross-sectional area equivalent to a circular cross-section glass fiber having an average fiber diameter of 16 μm, the appearance of the molded product after the weathering treatment is lowered, and the weather resistance Is inferior.
Comparative Example 3 using talc instead of glass fiber and glass beads resulted in poor laser transmittance, laser weldability, and weather resistance.

  The laser welding resin composition of the present invention has a high laser light transmittance and excellent laser weldability, and is also excellent in appearance and weather resistance of a molded product. The present invention can be particularly suitably applied to manufacturing various parts such as industrial machine parts and other consumer parts by laser welding, and has very high industrial applicability.

1: Gate 2: Laser irradiation location

Claims (6)

  (A) To 100 parts by mass of the thermoplastic polyester resin, (B) glass fibers having an average fiber diameter of more than 15 μm and / or (C) 10 to 100 parts by mass of glass beads having an average particle diameter of 25 μm or more. A resin composition for laser welding.   (A) The resin composition for laser welding according to claim 1, wherein the thermoplastic polyester resin contains a polybutylene terephthalate resin.   The resin composition for laser welding according to claim 1 or 2, wherein the crystallization temperature (Tc) of the resin composition is 190 ° C or lower.   The laser welding molded article formed by shape | molding the laser welding resin composition of any one of Claims 1-3.   The molded article for laser welding according to claim 4, which is used on the transmission side during laser welding.   A laser welded body laser-welded using the molded article according to claim 4 or 5.