JP5034773B2 - Manufacturing method of composite molded article including process of welding using laser beam and composite molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a composite molded article involving a process for welding a fiber-reinforced thermoplastic resin molded article good in mechanical strength and excellent in laser weld characteristcs with use of laser light, and to provide the composite molded article strongly bonded by the method for production. <P>SOLUTION: The method for producing the composite molded article involves the process for welding the fiber-reinforced thermoplastic resin molded article for laser-welding, with a member composed of (B) a thermoplastic resin composition, by using laser light. The molded article is composed of (A) the fiber-reinforced thermoplastic resin composition containing (b) 10-150 pts.wt. reinforcing fiber, based on (a) 100 pts.wt. thermoplastic resin, wherein (b) the reinforcing fiber is characterized by having 0.7-10 mm weight average fiber length. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a method for producing a composite molded article including a step of welding using laser light, and a composite molded article produced by the production method. In particular, the present invention relates to a manufacturing method using a laser-welded fiber-reinforced thermoplastic resin molded article that can be firmly bonded to another resin member by laser welding.

In recent years, thermoplastic resin products that can be reduced in weight have been used for structural parts in the fields of automobiles and electronic / electrical equipment in place of metal. Examples of the thermoplastic resin used in these structural parts include polyester resins, polyamide resins, and polycarbonate resins. Among these, polyester resins and polyamide resins typified by polybutylene terephthalate resins and polyethylene terephthalate resins are used. Because of its excellent mechanical properties, electrical properties, heat resistance, dimensional stability, and other physical and chemical properties, it is widely used in vehicle parts, electrical / electronic equipment parts, precision equipment parts, and the like. In recent years, polybutylene terephthalate resin is used in products that seal electrical circuit parts such as vehicle electrical parts (control units, etc.), various sensor parts, connector parts, etc. It has been developed in products having a hollow portion such as a manifold.
In products that seal these electric circuit parts or products that have hollow parts, it may be necessary to weld or seal multiple members, and various welding and sealing techniques such as adhesive welding, vibration welding, ultrasonic Welding, hot plate welding, injection welding, laser welding techniques, etc. are used.

  However, welding with an adhesive has a problem of environmental load such as contamination of the surroundings in addition to time loss until curing. Ultrasonic welding, hot plate welding, and the like have been pointed out as problems such as damage to products due to vibration and heat, and post-treatment required due to generation of wear powder and burrs. In addition, injection welding often requires a special mold or molding machine, and further has a problem that it cannot be used unless the fluidity of the material is good.

  On the other hand, laser welding is a welding method in which a resin member that is transmissive (also referred to as non-absorbing or weakly absorbing) to laser light and a resin member that absorbs laser light are brought into contact with each other for welding. is there. This is a method of irradiating a bonding surface with laser light from the side of the transmissive resin member, and melting and bonding the resin member exhibiting absorbency for forming the bonding surface with the energy of laser light. Laser welding is recently attracting attention because it is non-pressure welded and does not generate wear powder or burrs and has little damage to the product.

  Moreover, when using as a structural material, since high rigidity is required, it can improve by adding fillers, such as glass fiber. However, when fillers such as glass fibers and glass flakes are added, there is a problem that the transmittance of the laser beam is lowered, and there is a problem that the content of the filler is limited in the member that irradiates the laser beam was there.

  In order to solve the above problem, there is a method of widening the welding condition width by controlling the melting point using a polybutylene terephthalate copolymer (Patent Document 1). With this method alone, the improvement in transmittance is small, and improvement in product wall thickness design margin cannot be expected. Moreover, the method of mix | blending an amorphous resin and an elastomer with a polybutylene terephthalate-type resin is disclosed (patent documents 2 and 3). Although this method may improve the transmittance, there is a problem that the transmittance is likely to vary depending on the blending and molding conditions.

It is a welding material for laminating the first resin member and the second resin member and irradiating laser light from the first resin member side to weld them together, and is weakly absorbing to the laser light. A laser welding material comprising a certain first resin member and a second resin member that is absorbable with laser light is described. As a specific example of the first resin member that is weakly absorbent to laser light, a resin composition in which a modified ethylene / α-olefin copolymer is blended with polyamide 6 is absorbent to laser light. As a specific example of the second resin member, a resin composition in which 0.3% by weight of carbon black is blended with polyamide 6 is described (Patent Document 4).
However, the resin composition of Patent Document 4 has insufficient mechanical strength and rigidity, and cannot be used for applications that require these performances.

Japanese Patent No. 3510817 Japanese Patent Laid-Open No. 2003-292752 JP 2004-315805 A JP 2004-148800 A

  The present invention has been made in view of the above circumstances, and an object thereof is composite molding including a step of welding a fiber-reinforced thermoplastic resin molded article having good mechanical strength and excellent laser welding characteristics using laser light. An object of the present invention is to provide a manufacturing method of a product and a composite molded product firmly bonded by the manufacturing method.

  As a result of intensive studies to solve the above problems, the present inventors have blended reinforcing fibers into the thermoplastic resin, and at the same time, keep the fiber length of the reinforcing fibers remaining in the molded product long, Specifically, by setting the weight average fiber length to 0.7 to 10 mm, the transmittance and mechanical strength (particularly, impact resistance) of the resin molded product are improved, and a thermoplastic resin having excellent laser welding characteristics. A molded product was obtained, and as a result, it was found that a composite molded product strongly bonded by laser welding was obtained, and the present invention was completed.

The present invention has been completed based on the above findings, and the gist thereof is as follows.
(1) In a molded article comprising a fiber reinforced thermoplastic resin composition (A) comprising (b) 10 to 150 parts by weight of reinforcing fiber with respect to 100 parts by weight of (a) thermoplastic resin, the molded article is (A) After the roving-like reinforcing fiber is coated with a thermoplastic resin, the pellet is cut to a length of 0.7 mm or more and manufactured by an injection or extrusion molding method. ) Using a laser beam, a laser welding fiber reinforced thermoplastic resin molded article and a thermoplastic resin composition (B), wherein the weight average fiber length of the reinforcing fiber is 0.7 to 10 mm. A method for producing a composite molded article including a step of welding.
(2) The method for producing a composite molded article according to (1), wherein the weight average fiber length of the (b) reinforcing fiber in the molded article comprising the fiber reinforced thermoplastic resin composition (A) is 1 to 10 mm.
(3) (a) The method for producing a composite molded article according to (1) or (2), wherein the thermoplastic resin is a resin containing at least one selected from the group consisting of a polyamide resin, a polyester resin, and a polycarbonate resin. .
(4) (a) The method for producing a composite molded article according to any one of (1) to (3), wherein 50% by weight or more in the thermoplastic resin is a polyamide resin or a polyester resin.
(5) The method for producing a composite molded article according to (3) or (4), wherein at least one monomer constituting at least one polyamide resin contains an aromatic ring.
(6) The polyamide resin contains, as a structural unit (p), at least one selected from a salt composed of an aliphatic diamine and an aromatic dicarboxylic acid and a salt composed of an aromatic diamine and an aliphatic dicarboxylic acid. The manufacturing method of the composite molded product in any one of-(5).
(7) The method for producing a composite molded product according to (6), wherein the structural unit (p) is 30 mol% or more of all structural units of the polyamide resin.
(8) The polyamide resin contains at least one selected from the salt consisting of hexamethylenediamine and terephthalic acid and / or isophthalic acid, and the salt consisting of xylylenediamine and adipic acid as the structural unit (p). (3) The manufacturing method of the composite molded product in any one of (7).
(9) The method for producing a composite molded article according to any one of (3) to (8), wherein the polyester resin is a polybutylene terephthalate resin.
(10) fiber-reinforced thermoplastic resin composition (A), further comprising 0.1 to 100 parts by weight per (c) an epoxy compound (a) 100 parts by weight of the thermoplastic resin, (9) The manufacturing method of the composite molded product of description.
(11) The method for producing a composite molded article according to any one of (1) to (10), wherein the fiber-reinforced thermoplastic resin composition (A) further contains (d) a colorant.
(12) (b) The method for producing a composite molded article according to any one of (1) to (11), wherein the reinforcing fiber is a glass fiber.
(13) The method for producing a composite molded article according to any one of (10) to (12), wherein the (c) epoxy compound is a bisphenol A type epoxy compound or a novolac type epoxy compound .
(14 ) Any one of (1) to ( 13 ), wherein the thermoplastic resin of the thermoplastic resin composition (B) is a resin containing at least one selected from the group consisting of a polyamide resin, a polyester resin, and a polycarbonate resin. A method for producing a composite molded article according to 1.
( 15 ) The method for producing a composite molded article according to any one of (1) to ( 14 ), wherein the thermoplastic resin of the thermoplastic resin composition (B) is a polyamide resin or a polybutylene terephthalate resin.
( 16 ) A composite molded article produced using the production method according to any one of (1) to ( 15 ).

  According to the present invention, a fiber-reinforced thermoplastic resin molded article having excellent mechanical strength (particularly impact resistance) and excellent laser welding characteristics such as laser transmission, a laser welding method using the resin molded article, and the laser It has become possible to provide a method for producing a composite molded article including a welding step. Further, by using the method for producing a composite molded product including the laser welding process of the present invention, it has become possible to provide a composite molded product firmly bonded by laser welding. Such molded products are widely used industrially, and their utility value is extremely high.

  Hereinafter, the contents of the present invention will be described in detail. 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 resin>
The thermoplastic resin used in the present invention is not particularly limited as long as it can be molded. For example, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, styrene-acrylonitrile copolymer (AS resin), styrene- (meth) acrylic acid copolymer, styrene-methacrylic acid Polystyrene resins such as methyl copolymer, rubber-modified polystyrene (HIPS), acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), polyamide resin, polycarbonate resin , Polyacetal resin, polymethyl acrylate resin, polysulfone resin, polyphenylene oxide resin, and the like. These can be used alone or in combination of two or more. Among these, those having a high transmittance in a wavelength region of a laser usually used for thermoplastic resin welding (for example, YAG laser is 1064 nm and semiconductor laser is 655 to 980 nm) are preferable.

  The thermoplastic resin (a) employed in the present invention is at least one selected from the group consisting of a polyamide resin, a polyester resin, and a polycarbonate resin from the viewpoint of excellent balance of laser transmittance, mechanical properties, electrical properties, and heat resistance. A resin containing a seed is preferable, and (a) 50% by weight or more in the thermoplastic resin is more preferably a polyamide resin or a polyester resin.

  Specific examples of the polyamide resin in the present invention include various polyamide resins such as a lactam polycondensate, a polycondensate of diamine and dicarboxylic acid, and a polycondensate of ω-aminocarboxylic acid, or copolymers thereof. Polyamide resins and blends.

Examples of the lactam that is a raw material for polycondensation of polyamide resin include ε-caprolactam and ω-laurolactam.
Examples of the diamine include tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, octamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2-methylpentamethylene diamine, (2, 2, 4- or 2, 4, 4-) Trimethylhexamethylenediamine, 5-methylnonanemethylenediamine, metaxylylenediamine (MXDA), paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) ) Propane, bi (Aminopropyl) piperazine, aliphatic, such as aminoethylpiperazine, alicyclic, diamines aromatic or the like.
Examples of the dicarboxylic acid include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium. Examples thereof include aliphatic, alicyclic and aromatic dicarboxylic acids such as sulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid.
Examples of the ω-aminocarboxylic acid include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, paraaminomethylbenzoic acid, and the like.

  As a raw material of the polyamide resin in the present invention, a compound having 4 to 15 carbon atoms is preferable. By setting the number of carbon atoms to 4 or more, it tends to be possible to suppress the hygroscopicity of the resulting polyamide resin from becoming too high, and by setting the number of carbon atoms to 15 or less, the rigidity can be further increased. More specifically, ε-caprolactam as the lactam, hexamethylenediamine and xylylenediamine as the diamine, and adipic acid, terephthalic acid and isophthalic acid as the dicarboxylic acid are easily available and advantageous in price. It is more preferable.

  The salt which is a structural unit of the polyamide resin can be obtained by neutralizing the above diamine and dicarboxylic acid in an aqueous solution at high temperature under pressure. The salt thus obtained, the above lactam, and ω-aminocarboxylic acid are condensed under pressure and high temperature to advance the oligomerization reaction, and then the polymerization proceeds under reduced pressure, which is used in the present invention. A polyamide resin can be produced.

  More preferably, the polyamide resin in the present invention includes a semi-aromatic polyamide resin and a blend of a semi-aromatic polyamide resin and an aliphatic polyamide resin as shown below. When blending and using a semi-aromatic polyamide resin and an aliphatic polyamide resin, the semi-aromatic polyamide resin and the aliphatic polyamide resin are preferably semi-aromatic polyamide resin / aliphatic polyamide resin = 95 / 5-20. / 80, more preferably in a weight ratio of 90/10 to 30/70.

  The semi-aromatic polyamide resin is a polyamide resin containing, as a structural unit (p), at least one selected from a salt composed of an aliphatic diamine and an aromatic dicarboxylic acid and a salt composed of an aromatic diamine and an aliphatic dicarboxylic acid. Yes, preferably at least selected from homopolymers and copolymers consisting only of the structural unit (p) or polyamide structural units (p), and salts consisting of lactams, aliphatic diamines and aliphatic dicarboxylic acids. It is a polyamide copolymer comprising one type of structural unit (q). When both the structural units (p) and (q) are included, the molar ratio of the structural units (p) and (q) is preferably (p) / (q) = 98/2 to 30/70. A more preferred molar ratio is (p) / (q) = 95/5 to 35/65, and even more preferably 90/10 to 40/60. By using such a polyamide structural unit, it is possible to more effectively suppress the water absorption rate of the polyamide resin from becoming too high, and to maintain good physical properties and dimensional accuracy at the time of water absorption, due to moisture at the time of laser welding. There is a tendency that defects such as foaming can be suppressed.

  Specific examples of such a preferred semi-aromatic polyamide resin include, for example, polyamide MXD6 mainly composed of a salt of metaxylylenediamine and adipic acid, metaxylylenediamine, paraxylylenediamine, and adipic acid as the main raw materials. Polyamide MP6, polyamide 6I mainly composed of hexamethylene diamine and isophthalic acid salt, salt of hexamethylene diamine and adipic acid / copolymer of salt of hexamethylene diamine and isophthalic acid (polyamide 66 / 6I) , A salt of hexamethylenediamine and isophthalic acid / a copolymer of a salt of hexamethylenediamine and terephthalic acid (polyamide 6I / 6T) and the like, and more preferably, polyamide MXD6, polyamide MP6 and polyamide 6I / 6T. is there.

The semi-aromatic polyamide resin preferably has a specific apparent melt viscosity. A preferred apparent melt viscosity is 750-8000 using a capillary rheometer (Capillograph 1C manufactured by Toyo Seiki Co., Ltd.), L / D of the capillary is 30 mm / 1 mm, temperature is 280 ° C., and shear rate is 100 sec ⁻¹ . Poise, more preferably 800 to 7500 poise, and still more preferably 850 to 7000 poise. By making the apparent melt viscosity 750 poise or more, the mechanical strength tends to be more excellent, and by setting it to 8000 poise or less, it is possible to prevent deterioration of fluidity and moldability.

Examples of the aliphatic polyamide resin include polyamide 4, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 66, polyamide 610, polyamide 612, and the like (polyamide 6/66 co-polymer). And a polyamide 6/12 copolymer).
The aliphatic polyamide resin preferably has a viscosity number of 70 to 200 ml / g measured at a temperature of 25 ° C. and 96 wt% sulfuric acid at a polyamide resin concentration of 0.5 wt% in accordance with the ISO 307 standard. By setting the viscosity number to 70 ml / g or more, the toughness and the appearance of the molded product can be made excellent. By setting the viscosity number to 200 ml / g or less, the compound and the molding process are facilitated, and a good appearance of the molded product is obtained. This is preferable.

  The terminal of the polyamide resin in the present invention may be sealed with a carboxylic acid or an amine, and is particularly preferably sealed with a carboxylic acid or amine having 6 to 22 carbon atoms. Specifically, examples of the carboxylic acid used for sealing include aliphatic monocarboxylic acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid. Examples of the amine include aliphatic primary amines such as hexylamine, octylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, and behenylamine. The amount of carboxylic acid or amine used for sealing is preferably about 30 μeq / g in consideration of the melt viscosity at the time of molding.

A wide variety of known polyester resins can be used.
The polyester resin is preferably a polyester resin composed of a dicarboxylic acid or a derivative thereof and a diol.
As the dicarboxylic acid or derivative thereof, aromatic dicarboxylic acid, alicyclic dicarboxylic acid, and aliphatic dicarboxylic acid, and esters of these lower alkyls or glycols are preferred, and aromatic dicarboxylic acids or their lower alkyls (for example, C1-4) or an ester of glycol is more preferable, and terephthalic acid or a lower alkyl ester thereof is more preferable.
Aromatic dicarboxylic acids include terephthalic acid, phthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-benzophenone dicarboxylic acid, 4,4′-diphenoxy. Preferred examples include ethanedicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid.
Preferred examples of the alicyclic dicarboxylic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.
Preferred examples of the aliphatic dicarboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.
These dicarboxylic acids or derivatives thereof may be used alone or in combination of two or more.

As the diol, aliphatic diol, alicyclic diol and aromatic diol are preferable.
The aliphatic diol is preferably an aliphatic diol having 2 to 20 carbon atoms, such as ethylene glycol, 1,4-butanediol, diethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, Preferable examples include polypropylene glycol, polytetramethylene glycol, dibutylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol and 1,8-octanediol.
The alicyclic diol is preferably an alicyclic diol having 2 to 20 carbon atoms, such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol and 1,4-cyclohexane. A preferred example is dimethylol.
The aromatic diol is preferably an aromatic diol having 6 to 14 carbon atoms, such as xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane and bis (4- Hydroxyphenyl) sulfone can be mentioned as a preferred example.
These diols may be used alone or in combination of two or more.

The polyester resin may have a hydroxycarboxylic acid, a monofunctional component, and / or a trifunctional or higher polyfunctional component.
Preferred examples of the hydroxycarboxylic acid include lactic acid, glycolic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 6-hydroxy-2-naphthalenecarboxylic acid and p-β-hydroxyethoxybenzoic acid.
Preferred examples of the monofunctional component include alkoxycarboxylic acid, stearyl alcohol, benzyl alcohol, stearic acid, benzoic acid, t-butylbenzoic acid and benzoylbenzoic acid.
Preferred examples of the trifunctional or higher polyfunctional component include tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol, and pentaerythritol.

  The polyester resin preferably contains a polybutylene terephthalate resin (PBT resin), more preferably a polybutylene terephthalate single polymer having terephthalic acid as the only dicarboxylic acid unit and 1,4-butanediol as the only diol unit. More preferred is coalescence. The PBT resin referred to in the present invention means that terephthalic acid accounts for 50 mol% or more of all dicarboxylic acid components, and 1,4-butanediol accounts for 50 mol% or more of all diols. The PBT resin further preferably has a terephthalic acid ratio in the dicarboxylic acid unit of 70 mol% or more, more preferably 90 mol% or more. Moreover, 70 mol% or more is preferable and the ratio of 1, 4- butanediol in a diol unit has more preferable 90 mol% or more. Use of such a PBT resin is preferred because mechanical properties and heat resistance tend to be further improved.

The PBT resin in the present invention was measured in a one-to-one (weight ratio) mixed solution of phenol and tetrachloroethane at 30 ° C. from the viewpoint of deterioration of mechanical properties due to breakage of reinforcing fibers and hydrolysis resistance. A PBT resin having an intrinsic viscosity of 0.3 to 1.2 dl / g is preferable. By making the intrinsic viscosity of the PBT resin 0.3 dl / g or more, the mechanical performance of the fiber reinforced resin composition obtained can be made excellent, and by making the intrinsic viscosity 1.2 dl / g or less The fluidity of the fiber-reinforced resin composition can be kept good, and the moldability tends to be improved. Furthermore, breakage of the reinforcing fibers in the molding process can be suppressed, the fiber length of the reinforcing fibers in the molded product can be kept long, and a decrease in mechanical strength tends to be easily suppressed. As the PBT resin, two or more kinds of PBT resins having different intrinsic viscosities may be used in combination to obtain an intrinsic viscosity within the above range.
Moreover, in order to suppress the strength fall by hydrolysis of PBT resin, it is preferable that the titanium content in PBT resin is 60 ppm or less on the basis of the weight of a titanium metal, and it is more preferable that it is 50 ppm or less. Titanium content can be adjusted with the compounding quantity of the titanium compound used at the time of manufacture of PBT resin.

When manufacturing a polyester resin, a well-known method is employable widely. For example, in the case of a PBT resin composed of a terephthalic acid component and a 1,4-butanediol component, either a direct polymerization method or a transesterification method can be employed. The direct polymerization method is, for example, a method in which terephthalic acid and 1,4-butanediol are directly esterified, and water is generated in the initial esterification reaction. The transesterification method is a method using, for example, dimethyl terephthalate as a main raw material, and alcohol is generated by an initial transesterification reaction. The direct esterification reaction is preferable from the viewpoint of raw material costs.
Further, the polyester resin may be produced by either a batch method or a continuous method with respect to the raw material supply or the polymer dispensing form. Furthermore, the initial esterification reaction or transesterification reaction is performed in a continuous operation, and the subsequent polycondensation is performed in a batch operation, or conversely, the initial esterification reaction or transesterification reaction is performed in a batch operation, followed by There is also a method of performing polycondensation in a continuous operation.

  In addition, when (a) a thermoplastic resin used in the present invention is used in combination with a polyester resin and another thermoplastic resin, it is excellent in laser permeability, durability, moldability, low water absorption, and impact strength. As the other thermoplastic resin, it is preferable to use one selected from polystyrene resins, aromatic polycarbonate resins, and alloys of these resins. When using together a polyester resin and another thermoplastic resin, it is preferable that 50 weight% or more in (a) thermoplastic resin is a polyester resin, and 60 weight% or more is more preferable. Furthermore, it is particularly preferable that the polyester resin is a polybutylene terephthalate resin.

As the polycarbonate resin in the present invention, either an aromatic polycarbonate resin or an aliphatic polycarbonate resin can be used, but an aromatic polycarbonate resin is preferred.
An aromatic polycarbonate resin is a thermoplastic polymer obtained by reacting an aromatic dihydroxy compound or a small amount of a polyhydroxy compound with phosgene or a carbonic acid diester. The aromatic polycarbonate resin may be branched or a copolymer. The production method of the aromatic polycarbonate resin is not particularly limited, and can be produced by a conventionally known phosgene method (interfacial polymerization method) or a melting method (transesterification method). Moreover, when using the aromatic polycarbonate resin obtained by a melting method, you may adjust and use the amount of OH groups of a terminal group.

  Examples of the aromatic dihydroxy compound used as a raw material for the aromatic polycarbonate resin include 2,2-bis (4-hydroxyphenyl) propane (that is, bisphenol A), tetramethylbisphenol A, and bis (4-hydroxyphenyl) -p-diisopropyl. Examples thereof include benzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, and bisphenol A is preferable. In addition, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above aromatic dihydroxy compound can also be used.

  In order to obtain a branched aromatic polycarbonate resin, a part of the above-mentioned aromatic dihydroxy compound is mixed with a branching agent such as phloroglucin, 4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene- 2,4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3, 1,3 Polyhydroxy compounds such as 5-tri (4-hydroxyphenyl) benzene and 1,1,1-tri (4-hydroxyphenyl) ethane, and 3,3-bis (4-hydroxyaryl) oxindole (ie, isatin) Bisphenol), 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like may be substituted. The amount of the compound to be substituted is usually 0.01 to 10 mol%, preferably 0.1 to 2 mol%, based on the aromatic dihydroxy compound.

  As the aromatic polycarbonate resin, among the above-mentioned, polycarbonate resin derived from 2,2-bis (4-hydroxyphenyl) propane, or 2,2-bis (4-hydroxyphenyl) propane and other aromatic dihydroxy Polycarbonate copolymers derived from the compounds are preferred. Further, it may be a copolymer mainly composed of a 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 aromatic polycarbonate resin mentioned above.

  The molecular weight of the aromatic polycarbonate resin is preferably 13,000 to 30,000, preferably 16,000 to 28,000 as a viscosity average molecular weight converted from the solution viscosity measured at a temperature of 25 ° C. using methylene chloride as a solvent. More preferably, 17,000 to 24,000 is even more preferable. By setting the viscosity average molecular weight to 30,000 or less, the fluidity is kept good, and by setting the viscosity average molecular weight to 13,000 or more, the impact strength can be further improved.

<(B) Reinforcing fiber>
(B) Reinforcing fiber used in the present invention is a fibrous reinforcing material usually used for resin reinforcement, and for example, glass fiber, carbon fiber, metal fiber, synthetic fiber, etc. can be used. However, glass fiber is preferable from the viewpoint of laser transmittance and reinforcing effect.

(B) As a reinforcing fiber, in order to improve interfacial adhesion with a thermoplastic resin and reduce the opacity factor due to void formation at the interface, generally a sizing agent or a surface treatment agent (for example, for polyester resins) , Epoxy resin, acrylic resin, urethane resin, silane coupling agent, titanate compound and other functional compounds) are preferably used. In particular, when a polyester resin is used as the thermoplastic resin (a), it is preferable to use a reinforcing fiber surface-treated with a silane coupling agent and / or an epoxy resin.
Examples of the silane coupling agent include amino silane, epoxy silane, allyl silane, and vinyl silane. Of these, aminosilanes are preferred. Preferred examples of the amino silane coupling agent include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ- (2-aminoethyl) aminopropyltrimethoxysilane. The content of the silane coupling agent in the surface treatment agent is preferably 0.1 to 8% by weight, and more preferably 0.5 to 5% by weight.
The epoxy resin is preferably a polyfunctional epoxy resin such as a phenol novolac type epoxy resin and a cresol novolac type epoxy resin. The content of the epoxy resin in the surface treatment agent is preferably 1 to 20% by weight, and more preferably 2 to 10% by weight.
(B) As a component contained in the surface treating agent used for the reinforcing fiber, a combination of an amino-based silane coupling agent and a novolac type epoxy resin is particularly preferable. By making the surface treating agent such a configuration, the inorganic functional group of the amino silane coupling agent is (b) the reinforcing fiber surface, the organic functional group of aminosilane is the glycidyl group of the epoxy resin, and the glycidyl group of the epoxy resin. Is rich in reactivity with the polyester resin, and (b) the interfacial adhesion between the reinforcing fiber and the epoxy resin is improved. As a result, the mechanical properties and hydrolysis resistance of the resin composition of the present invention are improved, and further, the opacity due to void formation at the interface is reduced, so that the transmittance is also improved.
(B) The surface treatment agent used for the reinforcing fiber includes other components such as a urethane resin, an acrylic resin, an antistatic agent, a lubricant, a water repellent, and the like within the scope of the present invention. be able to.
As a treatment method with a surface treatment agent, for example, a surface treatment with a surface treatment agent can be performed in advance as described in JP-A Nos. 2001-172055 and 53-106749. And in the case of preparation of the resin composition of this invention, it can also surface-treat by adding a surface treating agent separately from untreated (b) reinforcement fiber.
(B) 0.01-5 weight% is preferable and the adhesion amount of the surface treating agent with respect to a reinforced fiber has more preferable 0.05-2 weight%. By making it 0.01% by weight or more, the mechanical strength tends to be more effectively improved, and by making it 2% by weight or less, a necessary and sufficient effect can be obtained and it is economical.

In the present invention, when the reinforcing fiber (b) is a glass fiber, the fiber diameter is preferably 10 to 20 μm from the viewpoint of further suppressing the breakage of the glass fiber and further improving the physical properties.
The glass fiber is preferably composed of A glass, C glass, E glass or the like, and E glass (non-alkali glass) is particularly preferable because it does not adversely affect the thermal stability of the polyester resin. A glass having a refractive index of 1.56 to 1.60 can also be used. The glass usually excludes B ₂ O ₃ and F ₂ components from the components constituting the E glass (refractive index of 1.55) used for polyester resin, and the ratio of components such as MgO, TiO ₂ , ZnO, etc. By using the glass, the laser transmittance of the resin composition of the present invention can be improved. Moreover, when using glass fiber, it is preferable to use a long fiber type (roving) type or a short fiber type (chopped strand), from the point of keeping the fiber length of the glass fiber in the molded product longer, It is more preferable to use a long fiber type.

  The glass fiber can be produced, for example, by the following method. First, melted glass is formed into a glass ball of a predetermined size called marble, heated and softened in a yarn-taking furnace called pushing, and allowed to flow down from a number of nozzles of the furnace table. Stretch with. When the glass fibers are to be bundled, the glass fibers are immersed in a bundling agent coating apparatus provided in the middle of the glass fibers so that the bundling agent is attached to the glass fibers, dried, and wound around a rotating drum. At this time, the average diameter of the glass fibers can be adjusted to a desired dimension by adjusting the nozzle diameter, the take-up speed, the take-up atmosphere temperature, and the like.

In the present invention, the weight average fiber length of the (b) reinforcing fiber remaining in the molded product is required to be 0.7 to 10 mm from the viewpoint of laser light transmittance and mechanical strength maintenance. In order to obtain better mechanical strength, the weight average fiber length is more preferably 1 to 10 mm, further preferably 1.5 to 10 mm, and particularly preferably 2 to 10 mm.
In the present invention, for example, in the examples described later, the fiber length is measured by cutting out a sample of about 5 g from the center of the molded product, and burning only the thermoplastic resin component in an electric furnace at a temperature of 500 ° C. The dispersed fiber is dispersed on a slide glass, an arbitrary part is captured as an image in the range of 1000 to 2000 using an optical microscope with a CCD camera, the fiber length is measured with image analysis software, and the weight average fiber length is calculated. did.

In order to achieve the weight average fiber length condition, it is necessary to ensure such a fiber length at least at the stage of the resin composition pellets used for injection or extrusion molding. Examples of the method for producing the resin composition pellets in which the fiber length is ensured include, for example, a method in which a reinforced fiber mat is pressed with a molten resin sheet from both sides and a rectangular parallelepiped is formed with a sheet cutter, or a reinforcing fiber. For example, a method in which the roving surface is coated with a resin to form a strand and then cut into pellets is employed. Moreover, when manufacturing a resin composition pellet by melt kneading | mixing, it is necessary to select the kneading | mixing conditions that a reinforcement fiber is not damaged at the time of kneading | mixing.
Among these, the pulverization molding method (US Pat. No. 3,425,570, JP-A-53-53) can be used because the reinforcing fibers can be efficiently arranged in parallel with the length direction of the pellet and the dispersion of the fibers can be improved. No. 50279, etc.) is preferably employed.

  The pultrusion method is basically a method of impregnating a resin while drawing a continuous reinforcing fiber bundle, for example, a method of impregnating a fiber through an impregnation bath containing a resin emulsion, suspension or solution, A method in which resin powder is blown onto the fiber or the fiber is passed through a tank containing the powder and the resin powder is adhered to the fiber, and then the resin is melted and impregnated. From an extruder or the like while passing the fiber through the crosshead A method of supplying and impregnating a molten resin to a crosshead is known, and any of them can be used. Particularly preferable as a molding material is that a molten resin is supplied to the crosshead from an extruder or the like while passing the fiber through the crosshead, and after impregnation and cooling, the length is preferably 0.7 to 50 mm, more preferably 1 -50 mm, more preferably 3 to 40 mm in length, particularly preferably 4 to 30 mm in the form of pellets. Since the reinforcing fibers in the resin composition pellets thus obtained are substantially parallel to the length direction of the pellets, the length of the reinforcing fibers and the length of the pellets are substantially equal. By setting the length of the pellet to 0.7 mm or more, the length of the reinforcing fiber is also increased, so that the laser light permeability and the reinforcing effect when formed into a molded product can be further increased, which is preferable. In addition, by controlling the pellet length to 50 mm or less, it is possible to suppress the increase in bulk density, prevent the occurrence of bridging in the hopper during molding and the phenomenon of poor biting into the screw, and stable molding is possible. preferable.

When manufacturing a resin composition pellet by melt-kneading, it becomes easy to keep the reinforcing fiber in a pellet longer by using the following methods, for example.
Among the raw material (a) thermoplastic resin, for example, a polyester resin, a polyamide resin, or the like is preferably used. Since these thermoplastic resins have good fluidity at the time of melting, breakage of reinforcing fibers at the time of melt kneading can be suppressed.
As the (b) reinforcing fiber of the raw material used for melt-kneading, it is preferable to use an average fiber length of, for example, 1.5 to 30 mm, more preferably 2 to 30 mm, and 2.5 to 25 mm. More preferred. The reinforcing fiber is preferably an inorganic fiber having a high reinforcing effect, and glass fiber and carbon fiber are particularly preferable. In particular, glass fibers are preferable because they are not easily damaged during melt-kneading, are easily available, and are highly economical. Moreover, it is preferable to use this glass fiber in the form of a chopped strand from the surface of workability | operativity at the time of kneading | mixing. By using such a reinforcing fiber, the weight average fiber length of the reinforcing fiber in the resin composition pellet obtained can be kept longer.

For melt kneading, for example, various extruders, Brabender plastographs, lab plast mills, kneaders, Banbury mixers and the like are used. In this invention, the method of using the uniaxial or biaxial extruder which has the equipment which can be devolatilized from a vent port as a kneading machine is preferable. The (a) thermoplastic resin, (b) reinforcing fibers, and additives that are blended as necessary may be mixed in advance or may be put into a melt-kneader without mixing. When mixing in advance, it is preferable to use a ribbon blender, a Henschel mixer, a drum blender, or the like, for example, and adjust the mixing time and the number of rotations so that the reinforcing fibers are not damaged as much as possible.
The heating temperature at the time of melt kneading is usually 230 to 280 ° C., but it is preferable to set the plasticizing temperature of the molten resin higher than usual in order to reduce the pressure of the molten resin at the time of kneading. For example, when a polybutylene terephthalate resin is melt-mixed, it is preferable to set the barrel temperature of the extruder to 260 to 280 ° C. Further, (a) the thermoplastic resin, (b) the reinforcing fiber, and the additive blended as necessary may be supplied to the kneader in a lump or sequentially. In the present invention, in order to reduce the breakage of the reinforcing fibers, it is effective to design the extruder so that the reinforcing fibers are supplied immediately downstream of the barrel where the melting of the thermoplastic resin is completed.
By adopting any of the above conditions, or by combining a plurality of conditions, the fiber length of the reinforcing fibers in the resin composition pellet can be kept longer. When producing resin composition pellets by melt kneading, the preferred weight average fiber length of reinforcing fibers in the resin composition pellets is 1 to 20 mm, more preferably 1.5 to 20 mm, and even more preferably 2 to 2 mm. 15 mm.

  In addition to the method described above, (a) a thermoplastic resin, (b) reinforcing fiber, and additive components blended as necessary are premixed in a ribbon blender, Henschel mixer, drum blender, etc. It is also effective to use the dry blend as it is for molding without melt-kneading. When this method is used, it is possible to avoid breakage of the reinforcing fibers in the melt-kneading, so that it is possible to keep the reinforcing fiber length in the obtained molded product longer.

In the present invention, the weight average fiber length of the reinforcing fibers in the molded article made of the fiber-reinforced thermoplastic resin composition (A) is 0.7 to 10 mm, from the viewpoint of maintaining laser light transmittance and mechanical strength. It is necessary from.
In the injection and extrusion molding, the method of setting the weight average fiber length in the molded product to 0.7 to 10 mm so as not to break the reinforcing fiber is not limited to the method using the resin composition pellets and dry blend described above. , For example, screw configuration, processing of screw and cylinder inner walls, selection of molding machine conditions such as nozzle diameter and mold structure, adjustment of molding conditions such as plasticization, metering and injection, addition of other components to molding material, etc. There are various methods.
As a molding machine, for example, a method of using a screw with a looser compression type so as not to apply abrupt shearing to unmelted resin, or in-line screw type molding machine, a backflow prevention ring at the screw tip, etc. A method of increasing the clearance can be adopted.
In adjusting the molding conditions, it is particularly necessary to avoid plasticization and injection at a high shear rate. In the present invention, it is preferable to adjust, for example, cylinder temperature, back pressure, screw rotation speed, injection speed, and the like as conditions during plasticization, weighing, and injection. For example, when (a) the thermoplastic resin is a polyester resin, the temperature is preferably set to 250 to 290 ° C, more preferably 260 to 280 ° C when the cylinder temperature is adjusted. When adjusting the back pressure, it is preferably set to 0.25 to 5 MPa, more preferably 0.3 to 3 MPa. When adjusting a screw rotation speed, Preferably it sets to 30-150 rpm, More preferably, it is set to 40-100 rpm. When adjusting the injection speed, it is preferably set to 10 to 100 mm / sec, more preferably 10 to 50 mm / sec.
Adjust the molding machine conditions, cylinder temperature, back pressure, screw rotation speed, injection speed, and other molding conditions within the above-mentioned preferable range so as not to impair the moldability, reinforcing fiber dispersibility, and molded article physical properties. Or by combining two or more conditions within these preferable ranges, it is possible to mold at an appropriate melt viscosity and pressure, to prevent breakage of the reinforcing fiber, and to improve laser transmission and mechanical strength. It is possible to obtain an excellent molded product.

A method of adding other components to the molding material is also effective. For example, a method of adding a lubricant to lower the resin melt viscosity at the time of injection molding, a method of adding a plasticizer to improve resin fluidity, and the like are effective.
Examples of the lubricant and plasticizer include fatty acid metal salts such as stearic acid metal salts and montanic acid metal salts, aliphatic hydrocarbon compounds, higher alcohols, amide compounds, ester compounds, and the like. It is preferable to add in the range which does not affect. The blending amount of the lubricant or plasticizer is, for example, preferably 0.01 to 5 parts by weight, more preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the thermoplastic resin (a). The lubricant and plasticizer may be added during the production of the resin composition pellets, or may be dry blended with the resin composition pellets and used for molding. Further, it can be dry blended together with (a) a thermoplastic resin, (b) reinforcing fibers, and other components blended as necessary, and used for molding as it is.

  (B) Content of a reinforced fiber is 10-150 weight part with respect to 100 weight part of (a) thermoplastic resins, Preferably it is 20-100 weight part. By making the content of the reinforcing fiber 10 parts by weight or more, the mechanical strength can be made excellent, and by making it 150 parts by weight or less, the fluidity during molding can be made good. At the same time, it is possible to prevent crushing due to the fiber / fiber interaction and to keep the fiber length in the molded product long, so that the mechanical strength and the laser transmittance are improved.

<(C) Epoxy compound>
The (c) epoxy compound employed in the present invention is not particularly defined, and may be monofunctional, bifunctional or polyfunctional, or a mixture of two or more of these. In particular, a bifunctional or higher functional epoxy compound, that is, a compound having two or more epoxy groups in one molecule is preferable. The epoxy equivalent is preferably 100 to 5000 g / eq, more preferably 150 to 2000 g / eq.

(C) Preferred examples of the epoxy compound include glycidyl ether, diglycidyl ether, glycidyl ester, diglycidyl ester, alicyclic diepoxy compound, glycidyl imide compound, and novolac type epoxy compound.
As glycidyl ether, methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butylphenyl glycidyl ether and allyl glycidyl ether are preferable.
As the diglycidyl ether, bisphenol A diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether and propylene glycol diglycidyl ether are preferable.
As the glycidyl ester, benzoic acid glycidyl ester and sorbic acid glycidyl ester are preferable.
As the diglycidyl ester, adipic acid diglycidyl ester, terephthalic acid diglycidyl ester, orthophthalic acid diglycidyl ester and the like are preferable.
As the alicyclic diepoxy compound, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexylcarboxylate is preferable.
As the glycidyl imide compound, N-glycidyl phthalimide is preferable.
As the novolac type epoxy compound, a phenol novolac type epoxy compound and a cresol novolac type epoxy compound are preferable.

  Among these, glycidyl ether compounds obtained from the reaction of bisphenol A and epichlorohydrin, particularly phenols that are polyfunctional epoxy compounds obtained by the reaction of bisphenol A diglycidyl ether, phenol novolac and epichlorohydrin. A novolak type epoxy compound, a cresol novolak type epoxy compound which is a polyfunctional epoxy compound obtained by reaction of o-cresol and epichlorohydrin is preferably used.

  The (c) epoxy compound used in the present invention has reactivity and affinity with (a) a thermoplastic resin, in particular, a polyester resin. Therefore, when (a) the polyester resin is included as the thermoplastic resin, (c) the epoxy compound Is effective. In addition, (c) the epoxy compound has reactivity and affinity for the epoxy resin when the reinforcing fiber (b) is surface-treated with the epoxy resin. Because of these effects, (a) the adhesion between the thermoplastic resin and (b) the reinforcing fiber is increased, and the mechanical strength of the resin molded product of the present invention is improved, so that the bonding strength at the laser welding site is further increased. Is possible.

  (C) 0.1-100 weight part is preferable with respect to 100 weight part of (a) thermoplastic resins, and, as for content of an epoxy compound, 0.3-50 weight part is more preferable. (C) By setting the content of the epoxy compound to 0.1 parts by weight or more, the mechanical properties can be improved more effectively, and by setting it to 100 parts by weight or less, resin mixing, molding, etc. Hydrolysis is promoted when the resin is melted, and the strength tends to be further suppressed from decreasing, which is preferable.

<(D) Colorant>
You may mix | blend (d) colorants, such as dye and a pigment, with the fiber reinforced thermoplastic resin composition (A) in this invention. When blending a colorant, it is preferable to select and blend the dyes and pigments so that the light transmittance at a wavelength of 940 nm or 960 nm of a molded product having a thickness of 2 mm is 15% or more. As the dye, oil-soluble dyes and disperse dyes such as anthraquinone series, indigoid series, perylene series, perinone series, azo series, methine series, and phthalocyanine series can be preferably used. As the pigment, both inorganic pigments and organic pigments can be preferably used. Inorganic pigments include oxides, sulfides, sulfates, carbon black, and the like. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, and dioxazine. (D) Content of a coloring agent becomes like this. Preferably it is 0.005-5 weight part with respect to 100 weight part of (a) thermoplastic resins, More preferably, it is 0.01-1 weight part.

<Other additives>
The fiber-reinforced thermoplastic resin composition (A) in the present invention may be blended with other additives within the range not departing from the gist of the present invention. Other additives include antioxidants, heat stabilizers, flame retardants, mold release agents, catalyst deactivators, crystal nucleating agents, crystallization accelerators, and (b) inorganic fillers other than reinforcing fibers. be able to. These additives can be added during or after polymerization of the thermoplastic resin (a). Further, (a) In order to impart desired performance to the thermoplastic resin, an impact resistance improver, an ultraviolet absorber, a weather stabilizer, an antistatic agent, a foaming agent, and the like may be blended.

The antioxidant has the effect of improving the heat aging resistance of the resin composition more effectively and further improving the retention such as color tone, tensile strength, and elongation. As this antioxidant, it is preferable to mix | blend 1 or more types of antioxidant chosen from a phenolic antioxidant, sulfur type antioxidant, and phosphorus antioxidant. These antioxidants are particularly suitable for polyester resins, polyamide resins and polycarbonate resins.
The total amount of the antioxidant is preferably 0.001 to 2 parts by weight, more preferably 0.001 to 1.5 parts by weight, based on 100 parts by weight of the thermoplastic resin (a). Preferably it is 0.03-1 weight part.

  The phenolic antioxidant means an antioxidant having a phenolic hydroxyl group, and among them, a hindered phenolic antioxidant is preferably used. A hindered phenolic antioxidant is an antioxidant in which one or two carbon atoms adjacent to a carbon atom of an aromatic ring to which a phenolic hydroxyl group is bonded are substituted by a substituent having 4 or more carbon atoms. An agent. The substituent having 4 or more carbon atoms may be bonded to a carbon atom of the aromatic ring by a carbon-carbon bond, or may be bonded via an atom other than carbon.

  Non-hinders such as p-cyclohexylphenol, 3-t-butyl-4-methoxyphenol, 4,4′-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane as phenolic antioxidants Dophenol antioxidant, 2-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, 4-hydroxymethyl-2 , 6-di-t-butylphenol, styrenated phenol, 2,5-di-t-butylhydroquinone, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6- Xanthdiol bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (6-tert-butyl-4-ethylphenol), 2,2′-methylenebis [4-methyl-6- (1,3,5-trimethylhexyl) phenol], 4,4′-methylenebis (2,6-di-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 2 , 6-Bis (2-hydroxy-3-tert-butyl-5-methylbenzyl) -4-methylphenol, 1,1,3-tris [2-methyl-4-hydroxy Loxy-5-t-butylphenyl] butane, 1,3,5-trimethyl-2,4,6-tris [3,5-di-t-butyl-4-hydroxybenzyl] benzene, tris (3,5- Di-t-butyl-4-hydroxybenzyl) isocyanurate, tris [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 4,4′-thiobis (3- Methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), 4,4′-thiobis (2-methyl-6-tert-butylphenol), thiobis (β-naphthol) Hindered phenolic antioxidants, and the like. In particular, hindered phenol-based antioxidants can be suitably used as radical trapping agents because they tend to be stable radicals themselves. The molecular weight of the hindered phenol antioxidant is usually 200 or more, preferably 500 or more, and the upper limit is usually 3000.

  The sulfur-based antioxidant in the present invention refers to an antioxidant having a sulfur atom. For example, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3 -Dodecylthiopropionate), thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, nickel isopropyl Examples include xanthate and trilauryl trithiophosphite. In particular, a thioether-based antioxidant having a thioether structure can be suitably used because it receives oxygen from an oxidized substance and reduces it. The molecular weight of the sulfur-based antioxidant is usually 200 or more, preferably 500 or more, and the upper limit is usually 3000.

The phosphorus antioxidant in the present invention refers to an antioxidant having a phosphorus atom, and is preferably an antioxidant having a P (OR) ₃ structure. Here, R is an alkyl group, an alkylene group, an aryl group, an arylene group, etc., and three Rs may be the same or different, and any two Rs are bonded to each other to form a ring structure. It may be.
Examples of phosphorus antioxidants include triphenyl phosphite, diphenyl decyl phosphite, phenyl diisodecyl phosphite, tri (nonylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphos. Phyto, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, etc. are mentioned.

  In the fiber reinforced thermoplastic resin composition (A) used in the present invention, the blending amount of the phenolic antioxidant, the sulfurous antioxidant and the phosphorus antioxidant is (a) 100 parts by weight of the thermoplastic resin. Preferably it is 0.001-1.5 weight part, More preferably, it is 0.03-1 weight part. By making the blending amount of the antioxidant 0.001 part by weight or more, the antioxidant effect is better exhibited, and by making the blending amount of the antioxidant 1.5 parts by weight or less, oxidation heat stability It is possible to further suppress the deterioration of the resin and to make it more difficult for the resin to decompose during melt-kneading.

  A copper compound may be added as a heat stabilizer. When a polyamide resin is included as the thermoplastic resin, in particular, when a copper compound is added, the heat resistance of the resin composition is further improved, and a decrease in transmittance due to a deteriorated resin tends to be suppressed. Specific examples of copper compounds include cuprous chlorides such as cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, etc. And copper compounds of organic acids such as cupric sulfate, cupric nitrate, copper phosphate, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and the like Examples thereof include complex compounds of the copper halide compound with xylylenediamine, 2-mercaptobenzimidazole, benzimidazole, and the like. Among these, monovalent copper compounds are preferable, and cuprous acetate and cuprous iodide are more preferable.

  The compounding amount of the copper compound is not particularly limited, but is usually 0.01 to 2 parts by weight, preferably 0.015 to 1 part by weight based on 100 parts by weight of the thermoplastic resin (a). When the blending amount is 0.01 parts by weight or more, the thermal stability tends to be exhibited more easily, and when it is 2 parts by weight or less, it is more effective that the resin is colored and the mechanical properties are lowered. It is preferable because it tends to be suppressed. Two or more copper compounds may be used in combination.

  In the present invention, an alkali halide compound may be added. Particularly when (a) a polyamide resin is included as the thermoplastic resin, it is preferably used in combination with a copper compound. Examples of the alkali halide compound include, for example, lithium chloride, lithium bromide, lithium iodide, potassium chloride, potassium bromide, potassium iodide, sodium bromide and sodium iodide. You may use together. Among these, potassium iodide and sodium iodide are particularly preferable. When the copper compound and the alkali halide compound are used in combination, the amount of the copper compound is preferably 0.005 to 1 part by weight, more preferably 0.01 to 0.100 parts by weight per 100 parts by weight of the thermoplastic resin (a). 5 parts by weight, preferably an alkali halide compound is 0.01-2 parts by weight, more preferably 0.05-1 part by weight. Moreover, 0.015-3 weight part is preferable with respect to 100 weight part of (a) thermoplastic resins, and, as for the total compounding quantity of both, 0.06-1.5 weight part is more preferable.

The flame retardant is not particularly limited, and examples thereof include organic flame retardants such as organic halogen compounds, antimony compounds, phosphorus compounds, nitrogen compounds, and inorganic flame retardants. Examples of the organic halogen compound include brominated polycarbonate, brominated epoxy resin, brominated phenoxy resin, brominated polyphenylene ether resin, brominated polystyrene resin, brominated bisphenol A, pentabromobenzyl polyacrylate and the like. Examples of the antimony compound include antimony trioxide, antimony pentoxide, sodium antimonate, and the like. Examples of the phosphorus compound include phosphate esters, polyphosphoric acid, ammonium polyphosphate, red phosphorus, and phosphazene compounds such as phenoxyphosphazene and aminophosphazene having a bond of a phosphorus atom and a nitrogen atom in the main chain. Examples of the nitrogen compound include melamine, cyanuric acid, and melamine cyanurate. Examples of the inorganic flame retardant include aluminum hydroxide, magnesium hydroxide, silicon compound, boron compound and the like. The above flame retardants and flame retardant aids are particularly suitable for polyamide resins, polyester resins and polycarbonate resins.
The blending amount of these flame retardants is preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of (a) the thermoplastic resin. By setting the blending amount of the flame retardant to 0.1 parts by weight or more, flame retardancy can be expressed more effectively, and by setting it to 50 parts by weight or less, physical properties, particularly mechanical strength, are kept higher. be able to.

  Examples of the impact resistance improver include olefin-based, styrene-based, polyester-based, polyamide-based and urethane-based thermoplastic elastomers and core-shell polymers.

  Preferred as the olefin-based elastomer is a copolymer mainly composed of ethylene and / or propylene, specifically, an ethylene-propylene copolymer, an ethylene-butene copolymer, an ethylene-octene copolymer, an ethylene. -Propylene-butene copolymer, ethylene-propylene-diene copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-glycidyl methacrylate copolymer and the like. Among these, an ethylene-propylene copolymer and an ethylene-butene copolymer are more preferable from the viewpoint of easy modification in the case of acid modification and a large impact resistance improving effect.

  Examples of the styrene elastomer include a block copolymer composed of a polymer block mainly composed of a vinyl aromatic compound such as styrene and a polymer block mainly composed of an unhydrogenated and / or hydrogenated conjugated diene compound. . Examples of the vinyl aromatic compound constituting the block copolymer include styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, divinylbenzene, p-methylstyrene, 1,1-diphenylstyrene, and the like. One or more types can be selected from among them, and styrene is preferable among them. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, pyrylene, 3-butyl-1,3-octadiene, phenyl-1,3- One or more types can be selected from butadiene and the like, and butadiene, isoprene and combinations thereof are particularly preferable. The copolymerization ratio of the vinyl aromatic compound and the conjugated diene compound is preferably 5/95 to 70/30, and more preferably 10/90 to 60/40. Examples of such block copolymers include various a-b-a type triblocks such as styrene-ethylene-butylene-styrene copolymer (SEBS) and styrene-ethylene-propylene-styrene copolymer (SEPS). Structures are commercially available and are readily available.

  Polyester elastomers include aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate as hard segments, polyethers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, or polyethylene adipate, polybutylene adipate, and polycaprolactone. The block copolymer which uses the aliphatic polyester of this as a soft segment is mentioned. Although the polyester-type elastomer used by this invention is not limited to this, The polyester-type elastomer illustrated above is preferable from a compatible viewpoint.

  Examples of the polyamide-based elastomer include block copolymers in which polyamide 6, polyamide 66, polyamide 11, polyamide 12 and the like are hard segments and polyether or aliphatic polyester is a soft segment, but are not limited thereto. Absent. As the polyether and the aliphatic polyester, the same compounds as those used in the polyester elastomer can be used.

  As urethane-based elastomers, by reacting diisocyanates such as 4,4′-diphenylmethane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate and glycols such as ethylene glycol and tetramethylene glycol. Although the block copolymer which makes the obtained polyurethane a hard segment and makes a polyether or aliphatic polyester a soft segment is mentioned, it is not limited to this. As the polyether and the aliphatic polyester, the same compounds as those used in the polyester elastomer can be used.

  The core-shell polymer is a core-shell type graft copolymer in which a rubber layer is included in a glassy resin. The particle size of the rubber layer of the core is preferably 1.0 μm or less, more preferably 0.2 to 0.6 μm. When the weight average particle diameter of the rubber layer is 1.0 μm or less, the impact resistance improving effect tends to be more easily exhibited. Examples of the rubber layer include silicon-based, diene-based, and acrylic elastomers, and two or more of these may be copolymerized.

From the viewpoint of mechanical strength, thermal stability and fluidity, the impact resistance improver is preferably 0.05 to 5% by weight, more preferably about 0.2 to 4% by weight in the polymer. Or an epoxy-modified one is preferred.
The blending amount of the impact modifier is preferably 0.5 to 40 parts by weight, more preferably 2 to 35 parts by weight, and still more preferably 5 to 30 parts per 100 parts by weight of the thermoplastic resin (a). Parts by weight. By making the blending amount 0.5 parts by weight or more, the impact resistance can be made more excellent, and by making it 40 parts by weight or less, heat resistance, ultraviolet aging resistance, and a decrease in transmittance can be achieved. Can be suppressed.

  The thermoplastic resin composition of the present invention can be blended with a thermosetting resin such as an epoxy resin, a phenol resin, a melamine resin, and a silicone resin within a range not impairing the effects of the present invention. These thermosetting resins may be blended as part of (a) the thermoplastic resin, or may be used in combination of two or more. The blending amount of these thermosetting resins is preferably 50% by weight or less in the resin component, and more preferably 45% by weight or less.

  In the laser welding thermoplastic resin composition of the present invention, the light transmittance at a wavelength of 940 nm or 960 nm of a molded article having a thickness of 2 mm made of the resin composition is preferably 15% or more, and is 20% or more. It is more preferable.

  The molding method of the fiber reinforced thermoplastic resin composition (A) used in the present invention is a molding method generally used for thermoplastic resins, that is, a molding method such as injection molding, hollow molding, extrusion molding or press molding. Can be applied. A particularly preferable molding method is injection molding because of its good fluidity.

In the present invention, by using the fiber-reinforced thermoplastic resin composition (A) of the present invention, at least one of the members using the fiber-reinforced thermoplastic resin composition (A) can be firmly bonded to each other, It can be preferably used to produce a molded product having two or more resin members.
The shape of the member is not particularly limited, but is usually a shape having at least a surface contact portion (a flat surface or a curved surface) because the members are joined and used by laser welding.
In laser welding, laser light that has passed through a laser-transmitting member is absorbed by the laser-absorbing member, melted, and both members are welded. Since the fiber-reinforced thermoplastic resin composition (A) used in the present invention has high permeability to laser light, it can be preferably used as a member that transmits laser light. Here, the thickness of the member through which the laser is transmitted (thickness in the direction through which the laser beam is transmitted) can be appropriately determined in consideration of the use, the composition of the composition, and the like, and is, for example, 5 mm or less, preferably 4 mm or less.

As a laser light source used for laser welding of the present invention, for example, a gas laser such as an Ar laser (510 nm), a He—Ne laser (630 nm), a CO ₂ laser (10600 nm), or a liquid laser such as a dye laser (400 to 700 nm). Solid-state lasers such as YAG laser (1064 nm), semiconductor lasers (655 to 980 nm), and the like can be used. A semiconductor laser is preferably used in terms of beam quality and cost. Further, the laser type can be appropriately selected depending on the type of the welding partner material.

More specifically, when welding a molded article made of the fiber-reinforced thermoplastic resin composition (A) used in the present invention and a member made of the thermoplastic resin composition (B), first, the locations where the two are welded together Contact each other. At this time, surface contact is desirable between the two welded portions, and may be flat surfaces, curved surfaces, or a combination of flat and curved surfaces. Next, laser light is irradiated from the side of the molded article made of the fiber-reinforced thermoplastic resin composition (A) of the present invention (preferably irradiated perpendicularly to the adhesive surface). At this time, the laser beam may be condensed at the interface between the two using a lens system if necessary. The condensed beam is transmitted through the molded article made of the resin composition (A), absorbed near the surface of the member made of the resin composition (B), generates heat, and melts. Next, the heat is transferred to the molded product side made of the resin composition (A) by heat conduction and melted to form a molten pool at the interface between the two, and after cooling, the two are joined.
The composite molded product in which members are welded in this manner has a high bonding strength. In addition, the composite molded product in the present invention refers to a product in which at least two or more members are welded, and includes a member that forms a part of these in addition to a finished product or a part.

The member made of the thermoplastic resin composition (B) particularly includes at least a thermoplastic resin and can be welded to a molded product made of the fiber-reinforced thermoplastic resin composition (A) in the present invention. Not limited. Examples of the thermoplastic resin contained in the thermoplastic resin composition (B) include polyolefin resins, vinyl resins, polystyrene resins, acrylic resins, polyamide resins, polyester resins, polycarbonate resins, and polyacetal resins. And a mixture of two or more thermoplastic resins. In addition, the resin contained in the thermoplastic resin composition (B) may be a mixture of the thermoplastic resin and the thermosetting resin as described above. In the case of a mixture, 70% by weight or more of the resin component is preferably a thermoplastic resin. Furthermore, the above-mentioned fiber reinforced resin composition (A) may be sufficient as a thermoplastic resin composition (B). Among these, as the resin component of the thermoplastic resin composition (B), a resin containing at least one selected from the group consisting of polyamide resin, polyester resin, and polycarbonate resin is preferable, and 50% by weight or more of the resin component is polyamide. It is more preferably a resin or a polyester resin, further preferably a polyamide resin or a polyester resin alone, and particularly preferably a polyamide resin or a polybutylene terephthalate resin alone.
The resin contained in the thermoplastic resin composition (B) preferably has an absorption wavelength within the range of the wavelength of the laser beam to be irradiated. Furthermore, you may express the absorption characteristic by adding a light absorber, for example, a color pigment, etc. to the thermoplastic resin composition (B). Examples of the color pigment include inorganic pigments (black pigments such as carbon black (eg, acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black), red pigments such as iron oxide red, molyb And orange pigments such as date orange, white pigments such as titanium oxide) and organic pigments (yellow pigment, orange pigment, red pigment, blue pigment, green pigment, etc.). Among these, inorganic pigments generally have a strong hiding power and can be preferably used for the thermoplastic resin composition (B) on the laser absorption side. These light absorbers may be used alone or in combination of two or more. It is preferable that the compounding quantity of a light absorber is 0.01-1 weight part with respect to 100 weight part of resin components.

  The composite molded product obtained in the present invention has high welding strength and little resin damage due to laser light irradiation. Therefore, it can be used in various applications such as various storage containers, electrical / electronic parts, office automate (OA). It can be applied to equipment parts, home appliance parts, machine mechanism parts, vehicle mechanism parts, and the like. In particular, electric parts for vehicles (various control units, ignition coil parts, etc.), hollow parts for vehicles (various tanks, intake manifold parts, etc.), motor parts, various sensor parts, connector parts, switch parts, relay parts, coil parts, It can be suitably used for housings such as transformer parts and lamp parts.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example at all unless the summary is exceeded.

<Examples 1-7 , Reference Examples 8, 9 and Comparative Examples 1-3>
[Various measurement methods]
(1) Intrinsic viscosity Using an Ubbelohde viscometer, the intrinsic viscosity was determined as follows. That is, in a solvent mixture of phenol and tetrachloroethane in a weight ratio of 1: 1, the number of seconds falling only at 30 ° C. and a polymer solution having a concentration of 1.0 g / dl and the solvent was measured and determined from the following formula (1).

IV = ((1 + 4K _H η _sp ) ^0.5 −1) / (2K _H C) (1)
However, in Formula (1), it is (eta) _sp = ((eta) / (eta) ₀ ) -1, (eta) is polymer solution fall time, (eta) ₀ is fall time of a solvent, C is polymer solution density | concentration (g / dl), K _H is a constant of Haggins and set to 0.33.

(2) Reinforcing fiber content, weight average fiber length About 5 g of sample was cut out from the center part (including the light transmittance measurement site) of the test piece for light transmittance measurement produced by the method described below, and 500 ° C. After burning only the thermoplastic resin component in an electric furnace (“Electric Muffle Furnace KM-280” manufactured by Toyo Seisakusho Co., Ltd.), the weight of the remaining glass fiber was measured, and the ratio to the weight of the test piece before combustion was determined. It was set as the glass fiber content. Further, the obtained glass fiber is dispersed on a slide glass so as not to break, and an optical microscope with a CCD camera is used to capture an arbitrary portion as an image in the range of 1000 to 2000, and the length of the fiber is determined with image analysis software. Measurements were made. The weight average value of the obtained fiber lengths was defined as the weight average fiber length. The results are shown in Tables 1 and 2.

(3) Light transmittance, bending strength, flexural modulus Using various test specimens obtained by the methods described below, light transmittance, flexural strength and flexural modulus were measured. The light transmittance was measured using a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation: UV-3100PC), and the ratio of transmitted light intensity to incident light intensity in the near infrared region 800 to 1100 nm was expressed as a percentage. The bending strength and flexural modulus were measured in accordance with ASTM D790 standard for a test piece prepared under the same conditions as the test piece for measuring light transmittance. The evaluation results are shown in Tables 1 and 2.

(4) Tensile strength, Charpy impact strength For ISO test pieces for tensile and Charpy measurements obtained by the method described below, the tensile strength is notched in ISO 527 standard using “Strograph AP-II” manufactured by Toyo Seiki Seisakusho. Charpy impact strength was measured according to the ISO 179 standard. The evaluation results are shown in Tables 1 and 2.

(5) Laser weldability evaluation As shown in FIG. 1, the test pieces were overlapped and irradiated with laser. In FIG. 1, (a) shows a view of the test piece from the side, and (b) shows a view of the test piece from above. 1 is a test piece (length 128 mm, width 13 mm, thickness 1.6 mm) prepared under the same conditions as the light transmittance measurement test piece described below, and 2 is a thermoplastic resin composition which is a mating material to be joined. A test piece made of (B) (produced in the same manner as the test piece 1), 3 indicates a laser irradiation spot.
The test piece 1 was overlapped with the laser transmission side and the test piece 2 made of the resin composition (B) was overlapped with the laser absorption side, and the laser was irradiated from the transmission side. As the laser welding apparatus, a batch irradiation type “IRAM-300” manufactured by Nippon Emerson Co., Ltd. was used, the laser light wavelength was 960 nm, the welding spot was 3 mm × 6 mm, and the pressure was 4.8 MPa. A laser welding strength test was performed using a test piece welded after irradiation while changing the laser irradiation time. The welding strength is measured by using a tensile tester (Instron “5544”), and welding and integrating the test pieces 1 and 2 with clamps at both ends in the major axis direction. The sample was pulled at 5 mm / min, and the state of tensile shear fracture in the laser irradiated part was observed. When the tensile shear fracture strength of the laser irradiated portion was 25 MPa or more, it was judged as complete welding, and the weldability was evaluated by the laser irradiation time required for this. It can be said that the shorter the laser irradiation time required for this complete welding, the better the laser welding property. The evaluation results are shown in Tables 1 and 2.

[Production Method of Glass Fiber Reinforced Thermoplastic Resin Composition (A)]
Resin compositions for Examples 1, 6, and 7:
(B-1) Opening a continuous glass fiber roving (Asahi Fiber Glass Co., Ltd. “trade name: ER740TK”, fiber diameter 13 μm, refractive index (nd) 1.55) and passing it through an immersion die, After impregnating the molten resin supplied to the impregnation die, a pultrusion molding method of shaping, cooling, and cutting is used to contain 43 parts by weight of glass fiber with respect to 100 parts by weight of the thermoplastic resin. Fiber reinforced thermoplastic resin composition pellets were produced. As the thermoplastic resin, (a-1) polybutylene terephthalate resin (Mitsubishi Engineering Plastics "trade name: NOVADURAN (registered trademark) 5008", intrinsic viscosity 0.85 dl / g) was used by melting. . The glass fibers in the obtained pellets had a fiber diameter of 13 μm, had the same length as the pellets, and were arranged substantially parallel to the length direction of the pellets.

Resin composition for Example 2:
In Example 1, by adjusting the ratio of the (b-1) glass fiber roving amount and the (a-1) polybutylene terephthalate resin amount, the (b-1) glass fiber blending amount was changed to the polybutylene terephthalate resin 100. A fiber-reinforced thermoplastic resin composition pellet was produced in the same manner as in Example 1 except that the amount was changed to 100 parts by weight.

Resin composition for Example 3:
(A-1) 6 weight parts of (c) o-cresol novolak type epoxy compound (“trade name: YDCN-704” manufactured by Tohto Kasei Co., Ltd., epoxy equivalent: 195 to 220 g / eq) with respect to 100 parts by weight of polybutylene terephthalate resin Using a twin screw extruder (“Model: TEX30C” manufactured by Nippon Steel Works, screw diameter 30 mm), melt kneading is performed under the conditions of a cylinder temperature of 260 ° C. and a screw rotation speed of 200 rpm to obtain resin composition pellets. Obtained. Fiber reinforced thermoplastic resin composition pellets were produced in the same manner as in Example 1 except that the polybutylene terephthalate resin composition pellets thus obtained were used instead of the thermoplastic resin of Example 1.

Resin composition for Example 4:
(A-1) A thermoplastic resin masterbatch produced by blending (d-1) a methine-based oil-soluble dye-based colorant and a polybutylene terephthalate resin with respect to 100 parts by weight of the polybutylene terephthalate resin (Orient Chemical Co., Ltd.) “Product name: eBIND LTW-8950C”) was added in an amount of 4.3 parts by weight, and using a twin screw extruder (“Model: TEX30C” manufactured by Nippon Steel Works, screw diameter 30 mm), the cylinder temperature was 260 ° C., Melt-kneading was performed under the condition of a screw rotation speed of 200 rpm to obtain resin composition pellets. Fiber reinforced thermoplastic resin composition pellets were produced in the same manner as in Example 1 except that the polybutylene terephthalate resin composition pellets thus obtained were used instead of the thermoplastic resin of Example 1.

Resin composition for Example 5:
In Example 1, (b-1) of the glass fiber with respect to 100 parts by weight of the thermoplastic resin mixture comprising (a-1) polybutylene terephthalate resin and (a-2) polycarbonate resin (7: 3 by weight). A fiber-reinforced thermoplastic resin composition pellet was produced in the same manner as in Example 1 except that the blending amount was 67 parts by weight. As (a-2) polycarbonate resin, “trade name: Iupilon (registered trademark) H4000” manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used.

Resin composition for Reference Example 8 and Comparative Example 1:
(A-1) Polybutylene terephthalate resin is supplied from a hopper under the conditions of a cylinder temperature of 280 ° C. and a screw rotation speed of 200 rpm using a twin-screw extruder (“TEX30C” manufactured by Nippon Steel Co., Ltd., barrel 9 block configuration). , (A-1) 43 parts by weight of (b-2) glass fibers (chopped strands, “trade name: ECS03T-187” manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter 13 μm, cut with respect to 100 parts by weight of polybutylene terephthalate resin 3mm long, refractive index (nd) 1.55) is fed from the fifth block counted from the hopper by the side feed method, melt-kneaded and extruded, and the strand is cut into a length of 3 mm to produce fibers for injection molding Reinforced thermoplastic resin composition pellets were produced.

Resin composition for Reference Example 9:
(A-1) 100 parts by weight of polybutylene terephthalate resin (b-2) 43 parts by weight of glass fiber was mixed and mixed for 3 minutes with a tumbler, and this dry blend was used as a resin composition for injection molding. .

Resin composition for Comparative Example 2:
In Reference Example 8, (b-2) Fiber reinforced thermoplastic resin in the same manner as in Reference Example 8 except that the blending amount of the glass fiber was 100 parts by weight with respect to 100 parts by weight of (a-1) polybutylene terephthalate resin. Composition pellets were produced.

Comparative Example 3:
In Reference Example 8, (b-2) of glass fiber with respect to 100 parts by weight of a thermoplastic resin mixture composed of (a-1) polybutylene terephthalate resin and (a-2) polycarbonate resin (7 to 3 by weight). A fiber-reinforced thermoplastic resin composition pellet was produced in the same manner as in Reference Example 8 except that the blending amount was 67 parts by weight.

[Method for producing thermoplastic resin composition (B)]
(A-1) Two thermoplastic resin master batches ("trade name: PT20BLMB" manufactured by Mitsubishi Engineering Plastics) manufactured by blending carbon black and polybutylene terephthalate resin with 100 parts by weight of polybutylene terephthalate resin 0.02 parts by weight, and using a twin screw extruder (“Model: TEX30C” manufactured by Nippon Steel Co., Ltd., screw diameter: 30 mm), melt kneading was performed at a cylinder temperature of 260 ° C. and a screw rotation speed of 200 rpm to obtain a resin composition. Product pellets were obtained. Fiber-reinforced thermoplastic resin composition pellets were produced in the same manner as in Example 2 except that the polybutylene terephthalate resin composition thus obtained was used as a thermoplastic resin.

[Molding condition]
Test piece for light transmittance and bending measurement:
The fiber-reinforced thermoplastic resin pellets shown in Examples 1 to 7, Reference Example 8 and Comparative Examples 1 to 3 obtained by the above-described method and the dry blended product shown in Reference Example 9 were heated at 120 ° C. for 5 hours. After drying, using an injection molding machine (“Model: SE-50D” manufactured by Sumitomo Heavy Industries, Ltd.), the test piece (length) for light transmittance and bending measurement under the molding conditions shown in Tables 1 and 2 128 mm, width 13 mm, thickness 1.6 mm).

Test specimen for tensile test and Charpy impact test:
The fiber-reinforced thermoplastic resin pellets shown in Examples 1 to 7, Reference Example 8 and Comparative Examples 1 to 3 obtained by the above-described method and the dry blended product shown in Reference Example 9 were heated at 120 ° C. for 5 hours. After drying, using an injection molding machine (“Model: SG-75MIII” manufactured by Sumitomo Heavy Industries, Ltd.), ISO test pieces for tensile tests and Charpy impact tests were produced under the molding conditions shown in Tables 1 and 2. did.

From the results of Tables 1 and 2, the following can be estimated.
(1) When comparing Examples 1 and 6 to 7, Reference Examples 8 and 9 and Comparative Example 1, Example 2 and Comparative Example 2, and Example 5 and Comparative Example 3, respectively, the weight average fiber length in the molded product is It can be seen that when the length is long, the light transmittance is improved and the laser weldability is excellent. At the same time, it can be seen that the longer the weight-average fiber length, the better the mechanical strength, especially Charpy impact strength and bending strength, and the sufficient flexural modulus and tensile strength.
In particular, in Example 6, by raising the cylinder temperature at the time of injection molding, the weight average fiber length becomes longer by increasing the cylinder temperature at the time of injection molding, and laser weldability and mechanical strength are further improved. I understand that In Example 7, the back pressure at the time of injection molding is higher than that of Example 1, so that the reinforcing fibers are easily crushed and the weight average fiber length is shortened. Compared with Comparative Example 1 in which the pressure was set higher, the weight-average fiber length was relatively long at 1.44 mm, and thus it can be seen that the resin composition of Example 7 showed good laser weldability and mechanical properties.
Furthermore, Reference Example 8 and Comparative Example 1 are examples in which glass fibers are used in the form of chopped strands, but since Reference Example 8 keeps the back pressure during injection molding low, the weight average fiber length is It can be as long as 0.76 mm and shows good laser weldability, bending strength, and Charpy impact strength. Since the comparative example 1 has high back pressure, the weight average fiber length is short, and it can be seen that these performances are also insufficient.
Reference Example 9 is an example in which a polybutylene terephthalate resin and a glass fiber chopped strand are dry blended and used for molding. Even in this case, the resulting molded product exhibits good laser weldability and mechanical properties. I understand that.
(2) From the comparison of Examples 1 and 3, it can be seen that the light transmittance is further improved and the laser weldability is excellent by blending an epoxy compound.
(3) When a normal colorant is blended, the transmittance decreases, so laser weldability is often greatly reduced or cannot be welded. However, when the fiber-reinforced thermoplastic resin composition of the present invention is used, a colorant is blended. It can be seen from the comparison between Example 4 and Comparative Example 1 that good weldability can be maintained without significantly reducing the light transmittance.

<Examples 10 to 13, 16 to 18, 20, 21, Reference Examples 14, 15, 19, 22 and Comparative Examples 4 to 6>
[Various measurement methods]
(1) Reinforcing fiber content, weight average fiber length It measured by the method similar to the method as described in the said Examples 1-7 , Reference Examples 8 and 9, and Comparative Examples 1-3. The evaluation results are shown in Tables 3 and 4.

(2) Light transmittance, bending strength, bending elastic modulus Using various test specimens obtained by the methods described below, light transmittance, bending strength, and bending elastic modulus were measured. The light transmittance was measured using a visible / ultraviolet spectrophotometer (manufactured by Shimadzu Corporation: UV-3100PC), and the ratio of transmitted light intensity to incident light intensity in the near infrared region 940 nm was expressed as a percentage. The bending strength and flexural modulus were measured in accordance with ASTM D790 standard for a test piece (length 128 mm, width 13 mm, thickness 1.6 mm) produced under the same conditions as the light transmittance measurement test piece. The evaluation results are shown in Tables 3 and 4.

(3) Tensile strength, Charpy impact strength Measured in the same manner as described in Examples 1 to 7, Reference Examples 8 and 9, and Comparative Examples 1 to 3. The results are shown in Tables 3 and 4. The evaluation results are shown in Tables 3 and 4.

(4) Laser weldability evaluation As shown in FIG. 1, the test pieces were overlapped and irradiated with laser. In FIG. 1, (a) shows a view of the test piece from the side, and (b) shows a view of the test piece from above. 1 is a test piece (length 128 mm, width 13 mm, thickness 2 mm) prepared under the same conditions as the light transmittance measurement test piece described below, and 2 is a thermoplastic resin composition (B ) And 3 are laser irradiation locations, respectively.
The test piece 1 was overlapped with the laser transmission side and the test piece 2 made of the resin composition (B) was overlapped with the laser absorption side, and the laser was irradiated from the transmission side. As the laser welding apparatus, a “PARK LASER SYSTEM” manufactured by Scan Type Parker Corporation was used. The laser beam wavelength was 940 nm, the welding spot diameter was 0.6 mm, and the welding length was 13 mm. The scanning speed of the laser beam was 5 mm / sec, and the laser output was 18 W. The welding strength is measured by using a tensile tester (Instron “5544”), and welding and integrating the test pieces 1 and 2 with clamps at both ends in the major axis direction. Evaluation was performed by pulling at 5 mm / min. The tensile speed is indicated by the tensile shear fracture strength of the welded part. The evaluation results are shown in Tables 3 and 4.

[Production Method of Glass Fiber Reinforced Thermoplastic Resin Composition (A)]
Resin composition for Example 10:
(B-1) A continuous glass fiber roving ("trade name: ER740TK" manufactured by Asahi Fiber Glass Co., Ltd., fiber diameter 13 μm) is opened and taken through the impregnation die while being drawn, and the molten resin supplied to the impregnation die is After impregnation, a 10 mm long fiber reinforced thermoplastic resin composition pellet containing 100 parts by weight of glass fiber with respect to 100 parts by weight of thermoplastic resin is obtained by using a pultrusion method that is shaped, cooled, and cut. Manufactured. As the thermoplastic resin, (a-3) polyamide MXD6 (manufactured by Mitsubishi Gas Chemical Co., Ltd., “trade name: MX nylon 6000”, apparent melt viscosity 1600 poise (capillary rheometer (capillograph 1C manufactured by Toyo Seiki Seisakusho Co., Ltd.)) And 70 parts by weight of L / D of the capillary (measured at a temperature of 280 ° C. and a shear rate of 100 sec ⁻¹ ) and (a-5) polyamide 66 (manufactured by DuPont, “trade name: Zytel A mixture of 30 parts by weight of “101” and a viscosity of 150 ml / g (measured at a temperature of 25 ° C., 96% by weight sulfuric acid at a polyamide resin concentration of 0.5% by weight in accordance with ISO 307 standard) was used. The glass fiber in the obtained pellet has a fiber diameter of 13 μm, the same length as the pellet, and a substantially parallel arrangement in the length direction of the pellet. And it was something that.

Resin compositions for Examples 11 and 13:
In Example 10, by adjusting the ratio of (b-1) the glass fiber roving amount and the thermoplastic resin amount, (b-1) the glass fiber blending amount was 43 parts by weight with respect to 100 parts by weight of the thermoplastic resin. A fiber-reinforced thermoplastic resin composition pellet was produced in the same manner as in Example 10 except that the change was made.

Resin composition for Example 12:
(A-3) Polyamide MXD6 70 parts by weight and (a-5) Polyamide 66 A total of 100 parts by weight was produced by blending (d-2) an acid dye-based colorant and polyamide 6. 4.3 parts by weight of a thermoplastic resin masterbatch ("brand name: eBIND LTW-8620C" manufactured by Orient Chemical Industry Co., Ltd.) was added, and a twin screw extruder ("Model: TEX30C" manufactured by Nippon Steel Works, screw diameter 30 mm) Was melt kneaded under the conditions of a cylinder temperature of 260 ° C. and a screw rotation speed of 200 rpm to obtain resin composition pellets. Fiber-reinforced thermoplastic resin composition pellets were produced in the same manner as in Example 10, except that the polyamide resin composition pellets thus obtained were used instead of the thermoplastic resin of Example 10.

Resin composition for Reference Example 14 and Comparative Example 5:
(A-3) 70 parts by weight of polyamide MXD6 previously dry-blended using a twin screw extruder (“TEX30C” manufactured by Nippon Steel Co., Ltd., barrel 9 block configuration) under the conditions of a cylinder temperature of 260 ° C. and a screw rotation speed of 200 rpm. And (a-5) 30 parts by weight of a polyamide 66 mixture is supplied from a hopper, and 43 parts by weight of (b-3) glass fiber (chopped strand, manufactured by Nippon Electric Glass Co., Ltd. Name: ECS03T-289 ”, average fiber diameter 13 μm, cut length 3 mm, refractive index (nd) 1.55) is fed from the fifth block counted from the hopper by the side feed method, melt-kneaded, extruded, and strand Was cut into a length of 3 mm to produce a fiber-reinforced thermoplastic resin composition pellet for injection molding.

Resin composition for Reference Example 15:
(A-3) Polyamide MXD6 70 parts by weight and (a-5) Polyamide 66 30 parts by weight in total, 100 parts by weight of (b-3) glass fiber 43 parts by weight was mixed for 3 minutes with a tumbler. The dry blend was used as a resin composition for injection molding.

Resin compositions for Examples 16 to 18 In Example 10, (a-4) polyamide 6I / 6T (manufactured by Mitsubishi Engineering Plastics Co., Ltd., “trade name: Novamid (registered trademark) X21”, apparent melt viscosity 6500 30 parts by weight of a poise (capillary rheometer (Capillograph 1C manufactured by Toyo Seiki Seisakusho Co., Ltd., L / D of capillary measured at 30 mm / 1 mm, temperature 280 ° C., shear rate 100 sec ⁻¹ )) -6) Polyamide 6 (Mitsubishi Engineering Plastics Co., Ltd., trade name “Novamid (registered trademark) 1013J”, viscosity 138 ml / g (according to ISO 307 standard, temperature 25 ° C., 96 wt% sulfuric acid, polyamide (Measured at a resin concentration of 0.5% by weight) with respect to 100 parts by weight of 70 parts by weight of the mixed polyamide resin. (B-1) Fiber-reinforced thermoplastic resin composition pellets were produced in the same manner as in Example 10 except that the amount of glass fiber was 43 parts by weight.

Resin composition for Reference Example 19:
In Reference Example 14, the same procedure as in Reference Example 14 was performed except that the thermoplastic resin component was changed to a mixed polyamide resin of (a-4) 30 parts by weight of polyamide 6I / 6T and (a-6) 70 parts by weight of polyamide 6. Fiber reinforced thermoplastic resin composition pellets were produced.

Resin composition for Example 20:
In Example 10, the fiber reinforced thermoplastic resin composition was the same as Example 10 except that (a-5) 100 parts by weight of polyamide 66 and (b-1) the amount of glass fiber was 43 parts by weight. Product pellets were produced.

Resin composition for Example 21:
In Example 10, the fiber-reinforced thermoplastic resin composition was the same as in Example 10 except that (b-6) the amount of glass fiber was 43 parts by weight with respect to 100 parts by weight of (a-6) polyamide 6 Product pellets were produced.

Resin compositions for Reference Example 22 and Comparative Example 6:
Reference Example 14, except for changing the thermoplastic resin component (a-6) Polyamide 6 was producing a fiber-reinforced thermoplastic resin composition pellets in the same manner as in Reference Example 14.

Resin composition for Comparative Example 4:
In Reference Example 14, the blending amount of (b-3) glass fiber was 100 parts by weight with respect to a total of 100 parts by weight of (a-3) 70 parts by weight of polyamide MXD6 and (a-5) 30 parts by weight of polyamide 66. Except for the above, a fiber-reinforced thermoplastic resin composition pellet was produced in the same manner as in Reference Example 14.

[Method for producing thermoplastic resin composition (B)]
Carbon black (manufactured by Mitsubishi Chemical Co., Ltd., product number: MA600B) was blended in the resin composition of each of Examples and Comparative Examples described later at a ratio of 0.6 part by weight with respect to 100 parts by weight of the resin component. Using.

[Molding condition]
Test piece for light transmittance and bending measurement:
Fiber reinforced thermoplastics shown in Examples 10-13, Reference Example 14, Examples 16-18 , Reference Example 19, Examples 20, 21, Reference Example 22 and Comparative Examples 4-6 obtained by the above-described methods. After drying the resin pellet and the dry blend shown in Reference Example 5 at 120 ° C. for 5 hours, Tables 3 and 4 were used using an injection molding machine (“Model: SE-50D” manufactured by Sumitomo Heavy Industries, Ltd.). A test piece for measuring light transmittance (length 128 mm, width 13 mm, thickness 2 mm) and a test piece for bending test (length 128 mm, width 13 mm, thickness 1.6 mm) are produced under the molding conditions described in 1. did.

Test specimen for tensile test and Charpy impact test:
Fiber reinforced thermoplastic resin pellets shown in Examples 10-13 , Reference Examples 14 , 16-18 , Reference Example 19, Examples 20, 21, Reference Example 22, and Comparative Examples 4-6 obtained by the method described above. And after drying the dry blend shown in Reference Example 15 at 120 ° C. for 5 hours, it is described in Tables 3 and 4 using an injection molding machine (“Model: SG-75MIII” manufactured by Sumitomo Heavy Industries, Ltd.). Under the molding conditions, ISO test pieces for tensile test and Charpy impact test were prepared.

From the results of Tables 3 and 4, the following is estimated.
(1) From the results of Examples 10 to 13, Reference Examples 14 and 15, Examples 16 to 18, Reference Example 19, Examples 20, 21 and Reference Example 22, the weight average fiber length of the reinforcing fibers in the molded product was determined. It was found that by increasing the length, the fiber permeability, mechanical strength, and laser welding characteristics of the fiber reinforced resin composition were improved.
(2) When comparing Example 10 and Comparative Example 4, Examples 11 to 13, Reference Examples 14 and 15, and Comparative Example 5, Example 21, Reference Example 22 and Comparative Example 6, respectively, the weight average fiber in the molded product It can be seen that when the length is long, the light transmittance is improved and the laser weldability is excellent. At the same time, it can be seen that the longer the weight-average fiber length, the better the mechanical strength, especially Charpy impact strength and bending strength, and the sufficient flexural modulus and tensile strength.
(3) In Example 17, by raising the cylinder temperature at the time of injection molding, the weight average fiber length becomes longer by increasing the cylinder temperature at the time of injection molding than in Example 16, and the laser weldability and mechanical strength are further increased. It turns out that it improves.
(4) Example 13 has a higher back pressure at the time of injection molding than Example 11, so that the reinforcing fibers are easily crushed and the weight average fiber length is shortened, but chopped strands are used as the glass fibers, and at the time of injection molding Compared with Comparative Example 5 in which the back pressure was set higher, the weight-average fiber length was relatively long at 1.3 mm, so that the resin composition of Example 13 showed good laser weldability and mechanical properties. .
Furthermore, Reference Examples 14 and 15 and Comparative Example 5 are examples in which glass fibers are used in the form of chopped strands. However, Reference Examples 14 and 15 keep the back pressure during injection molding low, so the weight It can be seen that the average fiber lengths can be as long as 0.82 mm in Reference Example 14 and 1.0 mm in Reference Example 15 and show good laser weldability, bending strength, and Charpy impact strength. In Comparative Example 5, the back pressure is high, so the weight average fiber length is short, and it can be seen that these performances are also insufficient. Also regarding Examples 16 and 18, it can be seen that the relationship between the back pressure and the weight average fiber length has the same tendency as in the above examples.
(5) Reference Example 15 is an example in which a polyamide resin component and glass fiber chopped strands are dry blended and used for molding. Even in this case, the resulting molded product exhibits good laser weldability and mechanical properties. I understand that.
(6) When a normal colorant is blended, the transmittance decreases, so laser weldability is often greatly reduced or cannot be welded. However, when the fiber-reinforced thermoplastic resin composition of the present invention is used, a colorant is blended. It can be seen from the results of Example 12 that good weldability can be maintained without greatly reducing the light transmittance.

  According to the present invention, a fiber-reinforced thermoplastic resin molded article having excellent mechanical strength (particularly impact resistance) and excellent laser welding characteristics such as laser transmission, a laser welding method using the resin molded article, and the laser It has become possible to provide a method for producing a composite molded article including a welding step. According to the present invention, the range of product thickness that can be welded is widened, the degree of freedom in product design can be increased, and further, the range of laser welding conditions such as laser irradiation intensity and scanning speed can be widened. It has become possible to provide a molded product that is more firmly bonded. Such molded products are widely used industrially, and their utility value is extremely high.

FIG. 1 is a schematic diagram showing a laser weldability evaluation method in an embodiment of the present invention.

1 Test piece 1
2 Test piece 2
3 Laser irradiation points

Claims (16)

(A) In a molded article comprising a fiber reinforced thermoplastic resin composition (A) containing (b) 10 to 150 parts by weight of reinforcing fiber with respect to 100 parts by weight of thermoplastic resin, the molded article is (a ) After being coated with roving-like reinforcing fibers with a thermoplastic resin, it is manufactured by injection or extrusion using pellets cut to a length of 0.7 mm or more. (B) Reinforcing fibers in the molded product The step of welding a member comprising a fiber-reinforced thermoplastic resin molded article for laser welding and a thermoplastic resin composition (B) using a laser beam, wherein the weight average fiber length is 0.7 to 10 mm A method for producing a composite molded article comprising:   The manufacturing method of the composite molded product of Claim 1 whose weight average fiber length of (b) reinforced fiber is 1-10 mm in the molded product which consists of a fiber reinforced thermoplastic resin composition (A).   (A) The manufacturing method of the composite molded article of Claim 1 or 2 whose thermoplastic resin is resin containing at least 1 sort (s) chosen from the group which consists of a polyamide resin, a polyester resin, and a polycarbonate resin.   (A) The manufacturing method of the composite molded article of any one of Claims 1-3 whose 50 weight% or more in a thermoplastic resin is a polyamide resin or a polyester resin.   The method for producing a composite molded article according to claim 3 or 4, wherein at least one monomer constituting at least one polyamide resin contains an aromatic ring.   The polyamide resin contains at least one selected from a salt consisting of an aliphatic diamine and an aromatic dicarboxylic acid and a salt consisting of an aromatic diamine and an aliphatic dicarboxylic acid as the structural unit (p). The method for producing a composite molded article according to any one of the above items.   The manufacturing method of the composite molded product of Claim 6 whose structural unit (p) is 30 mol% or more in all the polyamide resin structural units.   The polyamide resin contains at least one selected from a salt composed of hexamethylenediamine and terephthalic acid and / or isophthalic acid, and a salt composed of xylylenediamine and adipic acid as a structural unit (p). The manufacturing method of the composite molded article of any one of -7.   The method for producing a composite molded article according to any one of claims 3 to 8, wherein the polyester resin is a polybutylene terephthalate resin. The composite according to claim 9, wherein the fiber-reinforced thermoplastic resin composition (A) further contains 0.1 to 100 parts by weight of (c) an epoxy compound with respect to 100 parts by weight of the thermoplastic resin (a). Manufacturing method of molded products.   The method for producing a composite molded article according to any one of claims 1 to 10, wherein the fiber-reinforced thermoplastic resin composition (A) further comprises (d) a colorant.   (B) The method for producing a composite molded article according to any one of claims 1 to 11, wherein the reinforcing fibers are glass fibers.   (C) The manufacturing method of the composite molded article of any one of Claims 10-12 whose epoxy compound is a bisphenol A type epoxy compound or a novolak type epoxy compound. Thermoplastic resin of the thermoplastic resin composition (B) is a polyamide resin, a polyester resin, a resin containing at least one selected from the group consisting of polycarbonate resin, according to any one of claims 1 to 13 A method for producing a composite molded product. The method for producing a composite molded article according to any one of claims 1 to 14 , wherein the thermoplastic resin of the thermoplastic resin composition (B) is a polyamide resin or a polybutylene terephthalate resin. A composite molded article produced by using the production method according to any one of claims 1 to 15 .

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