JP5127146B2 - Laser welding resin composition and composite molded body - Google Patents

Description

  The present invention relates to a resin composition and a molded body for laser welding for bonding to a resin molded body that is an object to be bonded using welding by irradiation with laser light, a laser welding method using the molded body, and the method thereof The present invention relates to a composite molded body obtained by the method.

  As a method of bonding resin members, a method of bonding resin members via an adhesive or a pressure-sensitive adhesive is known, but welding that directly bonds resin members from the viewpoints of recyclability and shortening of work processes is known. Attention has been focused on the joining method by the above. Among welding methods by welding, the laser welding method using laser light irradiation is less susceptible to heat and vibration than the hot plate welding method, ultrasonic welding method, and vibration welding method, and the shape of the resin molded product In recent years, it has attracted attention because it has the advantage that it can be joined efficiently without greatly depending on the above. However, in the laser welding method, when the resin molded body is welded, the resin member on the laser transmission side is required to have high transparency with respect to the laser beam, and usually has no transmittance of 20% or more, at least 10% or more. , Sufficient welding cannot be obtained.

  On the other hand, rubber-containing vinyl polymers such as acrylonitrile-butadiene-styrene copolymer (ABS resin) and impact-resistant polystyrene (HIPS) have mechanical properties such as strength and impact resistance, moldability, It has excellent characteristics and is used in a wide range of applications such as electrical and electronic parts, home appliances, office automation (OA) equipment, automotive parts, and sanitary products. However, since the rubber-containing vinyl polymer has low laser beam transmission, it is limited to bonding with a resin having high laser beam transmission.

  In view of this, Japanese Patent Application Laid-Open No. 2004-262961 (Patent Document 1) discloses a rubber reinforced resin (A1) obtained by polymerizing a vinyl monomer in the presence of a rubbery polymer (a), or this rubber reinforced resin. A wavelength of 808 nm when formed as a test piece having a thickness of 4 mm, comprising a thermoplastic resin (A) containing a composition (A2) of a resin (A1) and a (co) polymer (b) of a vinyl monomer. A laser welding molding material having a light transmittance of 5% or more is disclosed.

However, even this material has insufficient weldability and impact resistance, and gas is generated by laser welding depending on the type of rubber-reinforced resin.
Japanese Patent Laying-Open No. 2004-262961 (Claim 1)

  Accordingly, an object of the present invention is to provide a resin composition that can be strongly bonded to a bonded body (resin molded body) by laser light irradiation and that is excellent in various resin properties such as impact resistance and moldability. An object of the present invention is to provide the molded body, a laser welding method using the molded body, and a composite molded body obtained by the method.

  Another object of the present invention is to provide a laser welding resin composition that can be firmly bonded to an object to be bonded even when a rubber-containing vinyl polymer is used, and that can suppress the generation of gas during welding, and molding thereof. It is to provide a body, a laser welding method using the molded body, and a composite molded body obtained by the method.

  Still another object of the present invention is to achieve both laser permeability (or transparency) and flame retardancy at a high level without deteriorating the appearance and design properties even when laser-welded to the workpiece. An object of the present invention is to provide a flame-retardant resin composition for laser welding, a molded body thereof, a laser welding method using the molded body, and a composite molded body obtained by the method.

  As a result of diligent studies to achieve the above-mentioned problems, the inventors of the present invention have found that when a rubber-containing vinyl polymer is used and the ratio of the organic acid or salt thereof in the resin composition is adjusted to a certain range, the laser is strongly The present invention has been completed by finding that it can be welded and is excellent in various resin properties such as impact resistance and moldability.

That is, the resin composition for laser welding of the present invention is a resin composition that can be bonded to a resin molded body by irradiation with laser light, and is composed of a vinyl polymer (A) containing a rubber component. And the ratio of the organic acid or its salt contained in a resin composition is 10,000 ppm or less. The weight average particle diameter of the rubber component is, for example, about 230 to 3000 nm. The ratio of the rubber component contained in the resin composition is about 3 to 50% by weight (particularly 5 to 30% by weight). The organic acid or a salt thereof is, for example, an organic acid such as a C _6-30 saturated or unsaturated aliphatic carboxylic acid, terpenic acid, an organic sulfonic acid having a C _6-30 alkyl group, or a salt thereof. The ratio of the organic acid or salt thereof in the resin composition may be, for example, 5000 ppm or less. The rubber-containing vinyl polymer (A) may be a resin obtained by a bulk polymerization method. The rubber-containing vinyl polymer (A) is a polymer containing a vinyl monomer such as an aromatic vinyl monomer, a vinyl cyanide monomer, or an acrylic monomer as a constituent unit. A combination (for example, rubber-grafted styrene resin (A1) containing an acrylic monomer and / or a vinyl cyanide monomer as a constituent unit) may be used. The resin composition further includes a vinyl polymer (B) containing no rubber component (for example, a rubber-free styrene resin containing an acrylic monomer and / or a vinyl cyanide monomer as a constituent unit). (B1) etc.) may be included.

  The resin composition further includes at least one flame retardant (C1) selected from halogenated (iso) cyanuric acid ester (C1) (for example, tri (haloaryl) cyanurate) and aromatic condensed phosphoric acid ester (C2). ) May be included. Even when such a flame retardant is mixed with a thermoplastic resin, the laser transmittance is hardly lowered, so that the resin composition can be flame-retardant at a high level while maintaining the laser transmittance. The ratio of the flame retardant (C) may be, for example, about 1 to 70 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The resin composition containing such a flame retardant (C) can achieve both flame retardancy and laser transmittance at a high level. For example, in the resin composition, when measured at (i) a thickness of 1.5 mm The flame retardancy grade based on UL94 is V-2 or higher, and (ii) the laser beam transmittance may be 10% or higher in the thickness direction of the molded body having a thickness of 4 mm. Further, in the resin composition containing the flame retardant (C), the laser beam transmission retention rate R (%) represented by the following formula may be 50% or more.

R (%) = (T2 / T1) × 100
(In the formula, R is the laser beam transmission retention rate, T1 is the transmittance (%) with respect to the laser beam in the thickness direction of the molded product having a thickness of 4 mm of the resin composition not containing the flame retardant (C), and T2 is the flame retardant (C). The transmittance (%) with respect to the laser beam in the thickness direction of the molded product having a thickness of 4 mm of the resin composition containing s.
The molded body comprised with the said resin composition is also contained in this invention. The present invention also includes a composite molded body in which a first molded body composed of the resin composition and a second molded body composed of a thermoplastic resin are joined by laser light irradiation. It is. In this composite molded body, the molded body composed of the resin composition of the present invention is excellent in laser transmittance, and may be used as a transmissive member, for example.

  Further, the present invention includes a method of joining the first molded body composed of the resin composition and the second molded body composed of the thermoplastic resin by irradiating with laser light.

  Furthermore, in the present invention, the bonding property by laser irradiation between the first molded body composed of the vinyl polymer (A) containing the rubber component and the second molded body composed of the thermoplastic resin is provided. An improvement method is also included, in which the ratio of the organic acid or salt thereof in the resin composition composed of the rubber-containing vinyl polymer (A) is 10000 ppm or less.

  In the present invention, the resin composition for laser welding is composed of a rubber-containing vinyl polymer, and the ratio of the organic acid or salt thereof in the resin composition is adjusted to a certain amount or less. In addition to being able to be firmly joined to the object to be joined, it is also excellent in various resin properties such as impact resistance and moldability. In addition, despite the use of a rubber-containing vinyl polymer, it can be firmly bonded to the object to be bonded, and the amount of gas generated is small in welding. Furthermore, by using a flame retardant (particularly, a specific flame retardant such as a halogenated (iso) cyanuric acid ester or an aromatic condensed phosphoric acid ester), the laser transmittance is not impaired, and gas is not generated. Since flame retardancy can be achieved, even if laser welding is performed on an object to be bonded, appearance and design properties are not deteriorated, and both laser permeability (or transparency) and flame retardancy can be achieved at a high level.

[Laser welding resin composition]
The laser welding resin composition of the present invention is composed of a vinyl polymer (rubber-containing vinyl polymer) (A) containing at least a rubber component. This resin composition may further contain a vinyl polymer containing no rubber component (rubber-free vinyl polymer) (B).

(A) Rubber-containing vinyl polymer A rubber-containing vinyl polymer has a rubber-like polymer (rubber component) in a matrix composed of a vinyl polymer by copolymerization (graft polymerization, block polymerization, etc.). A polymer dispersed in the form of particles may be used. Usually, at least a vinyl monomer is used in the presence of a rubbery polymer by a conventional method (bulk polymerization, bulk suspension polymerization, solution polymerization, emulsion polymerization, etc.). It is a graft copolymer (rubber graft vinyl polymer) obtained by polymerization.

  Examples of vinyl monomers include aromatic vinyl monomers, vinyl cyanide monomers, acrylic monomers, vinyl ester monomers, unsaturated polycarboxylic acids or acid anhydrides, imides System monomers and the like are included. In addition, the vinyl monomer may be a vinyl halide monomer such as vinyl chloride, but a non-halogen monomer is preferable from the viewpoint of weldability. These vinyl monomers can be used alone or in combination of two or more.

  Examples of aromatic vinyl monomers include styrene, alkyl-substituted styrene (eg, vinyl toluene, vinyl xylene, p-ethyl styrene, p-isopropyl styrene, butyl styrene, pt-butyl styrene, etc.), halogen-substituted Examples thereof include styrene (for example, chlorostyrene, bromostyrene, etc.), α-alkyl-substituted styrene (for example, α-methylstyrene, etc.) having an alkyl group substituted at the α-position. These aromatic vinyl monomers can be used alone or in combination of two or more. Of these aromatic vinyl monomers, styrene monomers such as styrene, vinyl toluene, and α-methylstyrene (particularly styrene) are usually used.

  Examples of the vinyl cyanide monomer include (meth) acrylonitrile, halogenated (meth) acrylonitrile and the like. These vinyl cyanide monomers can be used alone or in combination of two or more. Of these vinyl cyanide monomers, (meth) acrylonitrile such as acrylonitrile is usually used.

Examples of the acrylic monomer include (meth) acrylic acid, (meth) acrylic acid C _1-20 alkyl ester [methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, ( Hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate], cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, ( And glycidyl (meth) acrylate, hydroxy C _2-4 alkyl ester (meth) acrylate [2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, etc.] and the like. These acrylic monomers can be used alone or in combination of two or more. Of these acrylic monomers, (meth) acrylic acid C _1-4 alkyl esters such as (meth) acrylic acid and methyl (meth) acrylate are usually used.

  Examples of vinyl ester monomers include carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate. These vinyl ester monomers can be used alone or in combination of two or more.

  As unsaturated polycarboxylic acid or its acid anhydride, maleic acid, itaconic acid, citraconic acid or its acid anhydride etc. are mentioned, for example. These (anhydrous) unsaturated polyvalent carboxylic acids can be used alone or in combination of two or more.

Examples of the imide monomer include maleimide, N-alkylmaleimide (for example, N—C _1-4 alkylmaleimide), N-cycloalkylmaleimide (for example, N-cyclohexylmaleimide), N-arylmaleimide (for example) Examples thereof include N-substituted maleimides such as N-phenylmaleimide). These imide monomers can be used alone or in combination of two or more.

Among these vinyl monomers, aromatic vinyl monomers such as styrene, vinyl cyanide monomers such as (meth) acrylonitrile, acrylic monomers [(meth) acrylic acid, methyl methacrylate (Meth) acrylic acid C _1-4 alkyl ester etc.], (anhydrous) unsaturated polyvalent carboxylic acid such as maleic acid, especially aromatic vinyl monomers, vinyl cyanide monomers An acrylic monomer is preferred.

  The vinyl monomer may be a mixed monomer thereof, and in particular, an aromatic vinyl monomer (preferably a styrene monomer such as styrene), an acrylic monomer, and a vinyl cyanide monomer. A combination with at least one selected from monomers and (anhydrous) unsaturated polycarboxylic acids (preferably at least one selected from acrylic monomers and vinyl cyanide monomers) is preferred.

  For example, when an aromatic vinyl monomer and a vinyl cyanide monomer are combined, the ratio (molar ratio) of the aromatic vinyl monomer to the vinyl cyanide monomer is the former / The latter can be selected from the range of about 95/5 to 5/95, for example, 90/10 to 10/90, preferably 80/20 to 20/80, and more preferably about 70/30 to 30/70.

  When the aromatic vinyl monomer and the acrylic monomer are combined, the ratio (molar ratio) of the aromatic vinyl monomer to the acrylic monomer is the former / the latter = 95/5 It can be selected from the range of about 5/95, preferably 90/10 to 10/90, preferably about 85/15 to 20/80.

  When aromatic vinyl monomer, vinyl cyanide monomer, and acrylic monomer are combined, aromatic vinyl monomer, vinyl cyanide monomer, and acrylic monomer The ratio (molar ratio) to the total body can be selected from the range of the former / the latter = 95/5 to 1/99, for example, 90/10 to 3/97, preferably 70/30 to 5/95, More preferably, it is about 50/50 to 10/90 (particularly 30/70 to 15/85). Furthermore, the ratio (molar ratio) of the cyan vinyl monomer and the acrylic monomer can be selected from the range of the former / the latter = 95/5 to 1/99, for example, 90/10 to 3/97. The ratio is preferably about 70/30 to 5/95, more preferably about 50/50 to 10/90.

  The weight average molecular weight of the vinyl polymer as the matrix resin can be selected from the range of about 10,000 to 1,000,000, for example, 25,000 to 750,000, preferably 30,000 to 600,000, Preferably it is about 40,000-600,000 (especially 50,000-500,000).

Examples of the rubber-like polymer include diene rubber [polybutadiene (low cis type or high cis type polybutadiene), polyisoprene, styrene-butadiene copolymer, styrene-isoprene copolymer, butadiene-acrylonitrile copolymer, isobutylene. -Isoprene copolymer, styrene-isobutylene-butadiene copolymer rubber, etc.], ethylene-vinyl acetate copolymer, acrylic rubber (copolymer elastomer having polyacrylic acid C _2-8 alkyl ester as a main component), ethylene -Α-olefin copolymer [ethylene-propylene rubber (EPR), etc.], ethylene-α-olefin-polyene copolymer [ethylene-propylene-diene rubber (EPDM), etc.], urethane rubber, silicone rubber, butyl rubber, water Diene rubber (hydrogenated steel) Down - butadiene copolymer, and hydrogenated butadiene polymer) and the like. In these rubbery polymers, the copolymer may be a random or block copolymer, and the block copolymer has a structure of AB type, ABA type, tapered type, radial teleblock type. Copolymers and the like are included. These rubbery polymers can be used alone or in combination of two or more.

  A preferred rubber component is a polymer of conjugated 1,3-diene or a derivative thereof, particularly a diene rubber such as polybutadiene (butadiene rubber), isoprene rubber, styrene-butadiene copolymer.

  In the rubber-containing vinyl polymer, the content of the rubber component is 1 to 80% by weight, preferably 3 to 60% by weight, and more preferably about 5 to 60% by weight. If the content of the rubber component is too small, the effect of improving the impact resistance is not sufficient, and if the content of the rubber component is too large, the rigidity decreases.

  The form of the rubber-like polymer dispersed in the matrix composed of the vinyl polymer is not particularly limited, and may be a salami structure, a core / shell structure, an onion structure, or the like.

  The particle diameter of the rubber component (rubber-like polymer) constituting the dispersed phase can be selected, for example, from a range of a weight average particle diameter of 230 to 3000 nm, preferably 240 to 2000 nm, more preferably about 240 to 1500 nm. When the average particle size is within this range, the balance between laser light transmission and mechanical properties such as impact resistance is excellent. The graft ratio of the rubbery polymer is about 5 to 150%, preferably about 10 to 150%.

  Examples of the rubber-containing vinyl polymer include impact-resistant polystyrene (HIPS), methyl methacrylate-modified HIPS (transparent HIPS), styrene-acrylonitrile-butadiene copolymer (ABS resin), and methyl methacrylate-modified ABS resin (transparent ABS resin), α-methylstyrene-modified ABS resin, imide-modified ABS resin, styrene-methyl methacrylate-butadiene copolymer (MBS resin), AXS resin, methyl methacrylate-modified AXS resin, and other rubber-containing styrene resins. It is done. Here, the AXS resin refers to a resin obtained by graft polymerization of acrylonitrile A and styrene S to rubber component X (acrylic rubber, chlorinated polyethylene, ethylene-propylene rubber, ethylene-vinyl acetate copolymer, etc.). These include acrylonitrile-acrylic rubber-styrene resin (AAS resin), acrylonitrile-ethylene-propylene rubber-styrene resin (AES resin), and the like. These rubber-containing vinyl polymers can be used alone or in combination of two or more. Among these, the rubber-containing vinyl polymer is a rubber-grafted styrene-based resin containing an acrylic monomer and / or a vinyl cyanide monomer as a constituent unit (an acrylic monomer and / or a rubber component). A copolymer obtained by graft polymerization of a vinyl cyanide monomer and a styrene monomer), for example, an ABS resin, an AAS resin, an AES resin, an MBS resin, a methyl methacrylate-modified ABS resin, or the like may be used.

(B) Rubber-free vinyl polymer The rubber-free (or unmodified) vinyl polymer (B) is obtained by polymerizing at least a vinyl monomer, and polymerizes the same vinyl monomer. It may be a homopolymer obtained by polymerization, or a copolymer obtained by polymerizing a plurality of different vinyl monomers.

  Examples of the rubber-free vinyl polymer (B) include vinyl polymers that are matrix resins of the rubber-containing vinyl polymer (A). Specifically, styrene resin [eg, polystyrene (GPPS), etc.], acrylic resin [eg, polymethyl methacrylate, etc.], aromatic vinyl monomer, vinyl cyanide monomer, and / or acrylic. Copolymers with monomers (for example, styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer (MS resin), acrylonitrile-styrene-methyl methacrylate copolymer, etc.), aromatic And a copolymer of an aromatic vinyl monomer and an unsaturated carboxylic anhydride [for example, a styrene-maleic anhydride copolymer (SMA resin), etc.]. These rubber-containing non-vinyl polymers (B) can be used alone or in combination of two or more.

  The rubber-free vinyl polymer (B) may be the same or the same resin as the matrix resin of the rubber-containing vinyl polymer (A) from the viewpoint of compatibility. Specifically, among these rubber-free vinyl polymers, a copolymer of an aromatic vinyl monomer and a vinyl cyanide monomer and / or an acrylic monomer (for example, AS A copolymer of a styrene monomer such as a resin and a vinyl cyanide monomer) is preferred. In a copolymer of an aromatic vinyl monomer and a vinyl cyanide monomer and / or an acrylic monomer, an aromatic vinyl monomer, a vinyl cyanide monomer and / or an acrylic About the ratio (molar ratio) with a type | system | group monomer, it is the same as that of the ratio as described in the term of the said rubber-containing vinyl polymer (A).

  The ratio (weight ratio) between the rubber-containing vinyl polymer (A) and the rubber-free vinyl polymer (B) can be selected from the range of the former / the latter = 100/0 to 1/99. It is 0-10 / 90 (for example, 95 / 5-10 / 90), preferably 100 / 0-15 / 85, more preferably about 100 / 0-20 / 80. When the rubber-free vinyl polymer (B) is used in combination with the rubber-containing vinyl polymer (A), the ratio of the rubber component in the resin composition and the content of the organic acid or salt thereof are determined according to the desired characteristics. Can be adjusted easily.

  The ratio of the rubber component contained in the laser welding resin composition of the present invention is, for example, 3 to 50% by weight, preferably 3 to 30% by weight, more preferably 5 to 30% by weight (particularly 10%) in the resin composition. ˜30% by weight). If the proportion of the rubber component is too small, the effect of improving the impact resistance is not sufficient, and if the proportion of the rubber component is too large, the rigidity decreases.

  The laser welding resin composition of the present invention may further contain other thermoplastic resin as long as the characteristics of the rubber-containing vinyl polymer (A) are not impaired. Examples of other thermoplastic resins include olefin resins, acrylic resins, vinyl resins, polycarbonate resins, polyamide resins, polyphenylene oxide resins, polyurethane resins, and the like. These other thermoplastic resins can be used alone or in combination of two or more. From the viewpoint of compatibility, acrylic resins, thermoplastic elastomers (such as styrene thermoplastic elastomers and polyester thermoplastic elastomers) are preferred.

  Moreover, from the viewpoint of improving flame retardancy, the resin composition may contain a polycarbonate resin. The polycarbonate resin includes a diol component composed of at least an aromatic diol component [for example, bisphenols (such as bisphenol A)], and carbonate precursors (carbonate-forming compounds, carbonates, carbonyl halides, haloformates, etc.) ) And a polycarbonate resin (for example, aromatic polycarbonate) obtained by reaction.

Examples of bisphenols include bis (hydroxyphenyl) alkanes [eg, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) Propane (bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (3 Bis (hydroxyphenyl) C _1-4 alkanes such as 5-dibromo-4-hydroxyphenyl) propane], bis (hydroxyphenyl) cycloalkanes [for example, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1 , 1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, etc. Bis (hydroxyphenyl) C _5-8 cycloalkane etc.], bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl-alkyl) arenes [for example, 4,4 ′-(m- Phenylenediisopropylidene) diphenol, etc.]. Bisphenols may be used alone or in combination of two or more.

The diol component includes bisphenols and other diol components {for example, aliphatic diols [for example, alkanediols (ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,4-pentanediol, etc. C _2-10 alkanediol), etc.], alicyclic diol compounds [eg, di (hydroxyC _1-4 alkyl) C _5-8 cycloalkanes such as cyclopentanedimethanol, cyclohexanedimethanol], aromatic aliphatic diols [ For example, di (hydroxyC _1-4 alkyl) C _6-10 arene etc. such as 1,4-benzenedimethanol, 1,3-benzenedimethanol, etc.] may be used.

  Preferred polycarbonate resins include aromatic polycarbonate resins (polycarbonate resins having an aromatic diol component as a polymerization component), and particularly bisphenol type polycarbonate resins (polycarbonate resins having at least a bisphenol as a polymerization component). It is done. By combining a specific flame retardant described later and an aromatic polycarbonate resin, the flame retardancy of the resin composition can be improved more efficiently.

  Polycarbonate resins may be used alone or in combination of two or more.

  When the resin composition contains a polycarbonate resin, the ratio of the vinyl polymer (A) containing the rubber component and the polycarbonate resin is the former / the latter (weight ratio) = 99/1 to 1/99 (for example, 98/2 to 2/98), preferably 97/3 to 3/97 (for example, 95/5 to 5/95), more preferably about 95/5 to 15/85.

  The resin composition of the present invention includes conventional additives such as compatibilizers, plasticizers, flame retardants, colorants, fillers (glass fibers, carbon fibers, metals) as long as the laser transmittance and resin properties are not deteriorated. Fillers, etc.), stabilizers (antioxidants, light stabilizers, heat stabilizers, etc.), lubricants, dispersants, foaming agents, antibacterial agents and the like may be included. These additives can be used alone or in combination of two or more.

  Among these additives, in particular, a filler may be used to suppress sink marks and improve heat resistance and mechanical properties. As the filler, a conventional inorganic or organic filler can be used, but from the viewpoint of laser transmission, a fibrous inorganic filler (for example, glass fiber, silica fiber, carbon fiber, alumina fiber, metal fiber, etc.), particularly Glass fiber can be preferably used. The average diameter of the glass fiber is, for example, about 1 to 50 μm (preferably 3 to 30 μm), and the average length may be, for example, about 100 μm to 12 mm (preferably 500 μm to 6 mm). A filler can be used individually or in combination of 2 or more types.

  The ratio of the filler can be selected from a range of about 0 to 100 parts by weight with respect to 100 parts by weight in total of the rubber-containing vinyl polymer (A) and the rubber-free vinyl polymer (B). -100 parts by weight, preferably 20-80 parts by weight, more preferably about 30-80 parts by weight.

  Further, in order to improve the appearance characteristics of the molded product, a colorant may be used in particular. The colorant includes a colorant that can transmit laser light and a colorant that is non-absorbable with respect to laser light. Examples of such colorants include various chromatic or achromatic colorants, such as white dyes and pigments (for example, inorganic pigments such as titanium white, calcium carbonate, zinc oxide, zinc sulfide, and lithopone), yellow dyes [for example, , Inorganic pigments such as cadmium yellow (cadmium yellow), yellow lead (chrome yellow), zinc chromate, ocher (ocher), organic pigments such as hansa yellow, benzidine yellow, and pigment yellow], orange dye pigments, red dye pigments [for example , Red pigment, amber, cadmium red (fire red), inorganic pigments such as red lead (lead tetroxide, Komyotan), organic pigments such as permanent red, lake red, watch chan red, brilliant carmine 6B], Blue dyes [for example, inorganic pigments such as bitumen, ultramarine blue, cobalt blue (tenal blue), phthalocyanine blue, etc. Machine pigments, green dyes and pigments [e.g., inorganic pigments such as chrome green, organic pigments such as phthalocyanine green] and the like.

  As the colorant, the dyes and pigments exemplified above may be used alone, or a plurality of colorants may be used in combination to adjust to a desired color tone. For example, the resin can be colored black using a plurality of (for example, 2 to 4) colorants using subtractive color mixing.

  The colorant may have a light scattering property. When such a colorant (for example, a pigment such as titanium oxide) is used, a light scattering property can be imparted to the molded product, and the bonded object can be effectively formed. It can also be concealed. In addition, when using a colorant that does not transmit laser light but reflects and diffuses it, the laser light is transmitted to the extent that laser welding is possible, so the content ratio in the resin composition and the thickness of the molded body are adjusted. It is preferred to use.

  The ratio of the colorant is not particularly limited, but can be appropriately selected according to the kind of the resin or the colorant, the oscillation wavelength of the laser beam, the color of the joined body, and the like. For example, the rubber-containing vinyl polymer (A) and the rubber 0 to 10 parts by weight (for example, 0.0001 to 10 parts by weight), preferably 0.001 to 7 parts by weight, and more preferably 0.8 to 10 parts by weight with respect to 100 parts by weight of the total amount of the non-containing vinyl polymer (B). About 01-5 weight part may be sufficient.

  Furthermore, the resin composition of this invention and the flame retardant (C) may be included. The flame retardant (C) is not particularly limited as long as the laser permeability can be maintained. For example, an inorganic flame retardant (water) is used depending on the type of thermoplastic resin (for example, the degree of laser permeability of the thermoplastic resin itself). Metal hydroxides such as magnesium oxide, metal oxides such as alumina, red phosphorus, etc.), organic flame retardants [for example, organic phosphorus flame retardants (phosphate compounds, phosphazene compounds, aromatic condensed phosphate esters, etc.), halogens Flame retardants (halogenated bisphenol compounds, halogenated epoxy compounds, halogenated (iso) cyanuric acid esters, etc.), hindered amine compounds, etc.]. These flame retardants may be used alone or in combination of two or more.

  Among these flame retardants, at least one selected from halogenated (iso) cyanuric acid ester (C1) and aromatic condensed phosphoric acid ester (C2) may be suitably used. Even if these specific flame retardants are mixed with the resin composition, the laser composition hardly deteriorates, so that the resin composition can be flame-retardant at a high level while maintaining the laser permeability. . That is, when a conventional flame retardant (such as an antimony flame retardant) is added to a thermoplastic resin, the laser transmittance is likely to be greatly reduced, so a thermoplastic resin (for example, a resin having no transparency such as an ABS resin). Even if laser welding is possible by itself, it is often impossible to perform laser welding by adding a flame retardant. However, when the specific flame retardant is used, the laser permeability of the thermoplastic resin can be maintained at a high level. Therefore, regardless of the type of the thermoplastic resin, in particular, a resin having a relatively low laser permeability such as an ABS resin. Even if it exists, it can provide reliably both a flame retardance and a laser weldability.

(Halogenated (iso) cyanuric acid ester (C1))
Examples of the halogenated (iso) cyanuric acid ester (C1) (for example, brominated (iso) cyanuric acid ester) include a compound represented by the following formula (1), a compound represented by the following formula (2), and the like. Is included.

(In the formula, R ^a , R ^b and R ^c are the same or different and each represents a hydrocarbon group which may have a substituent, provided that at least one of R ^a , R ^b and R ^c is (It is a hydrocarbon group having a halogen atom.)

(Wherein R ^d , R ^e and R ^f are the same or different and each represents a hydrocarbon group which may have a substituent, provided that at least one of R ^d , R ^e and R ^f is (It is a hydrocarbon group having a halogen atom.)
In the groups R ^{a to} R ^f in the above formulas (1) and (2), examples of the hydrocarbon group include an alkyl group (methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, pentyl group). C _1-20 alkyl group such as a group), alkenyl group (C _2-6 alkenyl group such as vinyl group, allyl group), cycloalkyl group (C _5-10 cycloalkyl group such as cyclopentyl group, cyclohexyl group, etc.) Etc.), aryl groups [C _6-10 aryl groups such as phenyl groups, alkylphenyl groups (tolyl groups, xylyl groups, etc.), preferably C _6-8 aryl groups, especially phenyl groups), aralkyl groups (benzyl groups, C _6-10 aryl-C _1-4 alkyl group such as phenethyl group) and the like.

The hydrocarbon group may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), hydroxyl group, alkoxy group (C _1-4 alkoxy group such as methoxy group), acyl group (acetyl group etc.) C _1-6 acyl group), alkoxycarbonyl group (C _1-4 alkoxycarbonyl group such as methoxycarbonyl group), amino group, N-substituted amino group (N, N-dialkylamino group etc.), nitro group, And a cyano group. These substituents may be substituted alone or in combination of two or more with the hydrocarbon group.

In the formula (1), at least one of the groups R ^a , R ^b and R ^c , or at least one of R ^d , R ^e and R ^{f in} the formula (2) has a halogen atom as a substituent. It is a hydrocarbon group. Such a hydrocarbon group may have a halogen atom and a substituent other than the halogen atom.

Typical hydrocarbon groups having a halogen atom include haloalkyl groups (for example, mono to trihalo C _1-10 alkyl groups such as dibromopropyl group, dibromobutyl group, tribromoneopentyl group, etc., preferably mono to tribromo C _{1. -8} alkyl groups, more preferably di- or tribromo C _1-5 alkyl groups, etc.), haloaryl groups [eg mono- to trihalo C ₆ such as dibromophenyl groups (such as 2,6-dibromophenyl groups), tribromophenyl groups, etc. _-10 aryl group, preferably di- or tribromo C _6-8 aryl group, more preferably di- or tribromophenyl group].

Representative halogenated (iso) cyanuric acid esters include, for example, halogenated cyanuric acid esters {for example, tri (haloalkyl) cyanurate [or 2,4,6-tri (haloalkyloxy) -1,3,5-triazine. For example, tris (halo C _1-8 alkyl) cyanurates such as tris (2,3-dibromopropyl) cyanurate, tris (2,3-dibromobutyl) cyanurate, tris (tribromoneopentyl) cyanurate, preferably tris ( Di- or tribromo C _1-6 alkyl) cyanurate etc.], corresponding to these tri (haloalkyl) cyanurates, wherein any of the haloalkyl groups is an alkyl group having no halogen atom [eg monoalkyl-di ( Haloalkyl) cyanurate etc.] Haloalkyl cyanurates; tri (haloaryl) cyanurates [or 2,4,6-tri (haloaryloxy) -1,3,5-triazines such as tris (2,6-dibromophenyl) cyanurate, tris (2 , 4,6-tribromophenyl) cyanurate (or 2,4,6-tris (2,4,6-tribromophenoxy) -1,3,5-triazine) and the like tris (halo C _6-10 aryl) Cyanurates, preferably tris (di or tribromoC _6-8 aryl) cyanurates, more preferably tris (di or tribromophenyl) cyanurates, etc.], corresponding to these tri (haloaryl) cyanurates, any of the haloaryl groups being halogen Cyanurates which are aryl groups having no atoms [eg monoaryl- Haloaryl cyanurates, such as (haloaryl) cyanurates, etc.}, halogenated isocyanurates {eg, tri (haloalkyl) isocyanurates [eg, tris (2,3-dibromopropyl) isocyanurate, tris (2,3 -Dibromobutyl) isocyanurate, tris (haloC _1-8 alkyl) isocyanurate such as tris (tribromoneopentyl) isocyanurate, preferably tris (such as di- or tribromoC _1-6 alkyl) isocyanurate), Corresponding to these tri (haloalkyl) isocyanurates, haloalkyls such as isocyanurates [eg monoalkyl-di (haloalkyl) isocyanurates] wherein any of the haloalkyl groups are alkyl groups that do not have a halogen atom Isocyanurates; tris (haloaryl) isocyanurates [eg tris (haloC _6-10 aryl) such as tris (2,6-dibromophenyl) isocyanurate, tris (2,4,6-tribromophenyl) isocyanurate Isocyanurates, preferably tris (di or tribromoC _6-8 aryl) isocyanurates, more preferably tris (di or tribromophenyl) isocyanurates, etc.], corresponding to these tri (haloaryl) isocyanurates, And isocyanurates [for example, haloaryl isocyanurates such as monoaryl-di (haloaryl) isocyanurate] etc., which is an aryl group having no halogen atom.

Preferred halogenated (iso) cyanuric acid esters include compounds having a haloaryl skeleton (haloaryl group) (eg, tri (haloaryl) cyanurate), particularly compounds having a bromoaryl group [eg, tris (di or tribromo). C _6-8 aryl) cyanurate and the like] are preferred.

  These halogenated (iso) cyanuric acid esters may be used alone or in combination of two or more.

(Aromatic condensed phosphate ester (C2))
The aromatic condensed phosphate ester (C2) is usually composed of a phosphorus component such as phosphorus oxychloride, a polyol composed of at least an aromatic polyol, and a monoalcohol (particularly monohydroxyarene such as a phenol). And a reaction product (especially aromatic condensed phosphate ester) having at least two (especially two) phosphate units in the molecule.

  The polyols only need to be composed of at least an aromatic polyol (usually polyhydric phenols, bisphenols, etc.), and may contain non-aromatic polyols (eg, aliphatic polyols, etc.). Usually, the polyols may be composed of an aromatic polyol alone.

Typical polyhydric phenols (polyhydroxybenzene) include, for example, dihydroxybenzene (resorcinol, hydroquinone, etc.), dihydroxybenzene having a substituent {alkyl-dihydroxybenzene [dihydroxytoluene, 5-t-butylresorcinol, dihydroxyxylene] Mono- or di-C _1-10 alkyl-dihydroxybenzenes such as 2,6-dihydroxy-p-xylene], aryl-dihydroxybenzenes such as C _6-10 aryl-dihydroxybenzenes such as 2,4-dihydroxybiphenyl ), Mono- or dihalo-dihydroxybenzenes (such as 2,4-difluorohydroquinone)}, etc .; trihydroxybenzenes corresponding to these dihydroxybenzenes Etc., and the like.

Typical bisphenols include 4,4′-dihydroxybiphenyl, bis (hydroxyphenyl) alkanes [for example, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1, 1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis It has a substituent such as (4-hydroxyphenyl) octane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane which may be bis _{(hydroxyphenyl) C 1-10} alkanes, bis (hydroxyphenyl) cycloalkanes For example, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) ) Bis (hydroxyphenyl) C _5-10 cycloalkane optionally having a substituent such as cyclohexane], bis (hydroxyphenyl) ethers corresponding thereto, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) ) Sulphoxides, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl-alkyl) arenes [4,4 ′-(m-phenylenediisopropylidene) diphenol, etc.], alkylene oxides thereof (for example, ethylene oxide) Examples include adducts.

  Of these, preferred polyols are dihydroxybenzenes [dihydroxybenzene (resorcinol, hydroquinone, etc.), alkyl-dihydroxybenzene, halo-dihydroxybenzene and the like which may have a substituent (particularly, a substituent). And resorcinol that may be present), bisphenols, and the like, and dihydroxybenzenes are particularly preferred.

Examples of monoalcohols (monohydroxy compounds) include non-aromatic monoalcohols (such as aliphatic alcohols) and monohydroxyarenes. The monoalcohols may usually be monohydroxyarenes. Typical monohydroxyarenes include, for example, phenols {for example, phenol, substituted phenols [alkylphenol (o-, m-, p-cresol, 2,6-dimethylphenol, 2,6-di- Mono- or di-C _1-10 alkylphenol such as t-butylphenol, preferably mono- or di-C _1-6 alkylphenol, more preferably di-C _1-4 alkylphenol), arylphenol (such as o-phenylphenol), cycloalkylphenol, etc. Monohydroxy C _6-10 arene optionally having a substituent such as phenol, alkoxyphenol (such as o-methoxyphenol), halophenol (such as chlorophenol), acylphenol, etc.] Including That.

  Of these monoalcohols, phenols and phenols having a hydrocarbon group are preferable, and alkylphenols are particularly preferable. The monoalcohols to be reacted with the phosphorus component and the polyols may be used alone or in combination of two or more.

Preferred aromatic condensed phosphate esters include aromatic condensed phosphate esters in which the monoalcohol is a monohydroxyarene, such as dihydroxybenzene bis (diaryl phosphate) {eg, resorcinol bis (diaryl phosphate) [eg, Resorcinol bis [di (mono to tri), such as resorcinol bis (diphenyl phosphate); resorcinol bis (dicresyl phosphate), resorcinol bis (dixyl phosphate) (eg resorcinol bis (di-2,6-xylyl phosphate), etc.) C _1-4 alkyl) phenyl phosphate], etc.], hydroquinone bisaryl phosphates [eg, hydroquinone bis (diphenyl phosphate); hydroquinone bis (dicresyl phosphate) Hydroquinone bis [di (mono to tri C _1-4 alkyl) phenyl phosphate], etc.] such as hydroquinone bis (dixylyl phosphate) (eg, hydroquinone bis (di-2,6-xylyl phosphate), etc.) Aromatic condensed phosphates whose polyols are dihydroxybenzenes and monoalcohols are monohydroxyarenes}, bisphenol bis (diaryl phosphates) {eg bisphenol A-bis (diaryl phosphates) [eg , bisphenol A- bis (diphenyl phosphate); bisphenol A- bis (dicresyl phosphate), bisphenol A- bis (dixylyl phosphate) bisphenol A- bis [di (mono- to _{tri-C 1-4} Al, such as Le) polyols, such as phenyl phosphate], etc.] are bisphenols, and mono-alcohols and aromatic condensed phosphoric acid ester} monohydroxy arenes. Particularly preferred aromatic condensed phosphate esters include dihydroxybenzene bis (diaryl phosphates) (particularly resorcinol bis (diaryl phosphates)). These aromatic condensed phosphate esters may be used alone or in combination of two or more.

  Of these flame retardants (C), the halogenated (iso) cyanuric acid ester (C1) has a particularly high flame retardant effect. Therefore, the flame retardant (C) may be composed of at least a halogenated (iso) cyanuric acid ester (C1). The flame retardant (C) may be composed of a halogenated (iso) cyanuric acid ester (C1) and an aromatic condensed phosphoric acid ester (C2). When the halogenated (iso) cyanuric acid ester (C1) and the aromatic condensed phosphoric acid ester (C2) are combined, these ratios are the former / the latter (weight ratio) = 99/1 to 99/1, preferably It may be about 97/3 to 10/90, more preferably about 95/5 to 20/80 (for example, 95/5 to 30/70).

  In the resin composition of the present invention, the ratio of the flame retardant (C) includes the entire thermoplastic resin constituting the resin composition (for example, the vinyl polymer (A), the vinyl polymer (A) and the rubber component). For example, 1 to 70 parts by weight, preferably 3 to 60 parts by weight per 100 parts by weight of the total amount of the vinyl polymer (B) and the total amount of the vinyl polymer (A) and the polycarbonate resin, etc. (For example, 5 to 55 parts by weight), more preferably about 8 to 50 parts by weight.

  In the present invention, the ratio of sodium, chlorine and sulfate ions contained in the laser welding resin composition is, for example, 10 ppm (μg / g) or less in total (for example, 0 to 10 ppm), preferably 0 to 5 ppm, Preferably it is about 0-1 ppm (especially 0-0.5 ppm).

  Such sodium, chlorine and sulfate ions are mixed in, for example, the production process of the rubber-containing vinyl polymer (A). However, when such elements and ions are present, the weldability of the resin member is reduced, and the gas It can also be a cause of occurrence. The content of these elements and ions may be reduced by purifying the rubber-containing vinyl polymer, but may be reduced by adjusting or selecting the production method. For example, when producing a rubber-containing vinyl polymer by emulsion polymerization, suspension polymerization, or solution polymerization (particularly emulsion polymerization), a solvent used for polymerization, a surfactant, a polymerization initiator, etc., or a salt used for salting out It is preferable to use a rubber-containing vinyl polymer produced by bulk polymerization because elements and ions derived from the above are mixed.

  The resin composition for laser welding of the present invention has an organic acid or salt ratio (total ratio when plural kinds of organic acids or salts thereof are included) in the resin composition of 10,000 ppm (μg / g) or less (for example, 0 to 10000 ppm), usually 5000 ppm or less (for example, 0 to 5000 ppm), preferably 2000 ppm or less (for example, 0 to 2000 ppm), more preferably 0 to 500 ppm or less (particularly 0 to 100 ppm). In the present invention, since the content of the organic acid or salt thereof in the resin composition is suppressed within this range, the amount of gas generated in laser welding is small, and the weldability can be improved.

  Organic acids include fatty acids and organic sulfonic acids. The fatty acid may be a lower fatty acid such as acetic acid or propionic acid, but is usually a higher fatty acid having 6 or more carbon atoms or terpenic acid. The sulfonic acid is usually an organic sulfonic acid having an alkyl group having 6 or more carbon atoms.

Examples of higher fatty acids include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, daturic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, and melicic acid. C _6-30 or saturated aliphatic carboxylic acid, linderic acid, sperm acid, oleic acid, elaidic acid, linoleic acid, linolenic acid, gadoleic acid, erucic acid, C _6-30 unsaturated aliphatic carboxylic acids such as brassidic acid, Or a combination thereof may be used.

  Examples of terpenic acids include monoterpenic acids such as citronellic acid, sesquiterpenic acids such as hinocic acid and santalic acid, abietic acid (rosin acid), pimaric acid, neoabietic acid, levopimaric acid, agatendicarboxylic acid, and rubenic acid. Diterpenic acid such as or a combination thereof.

The organic sulfonic acids, C _6-30 sulfonic acid having an alkyl group such as octyl sulfonate, nonyl sulfonate, dodecyl sulfonate, tetradecyl sulfonate, hexadecyl (cetyl) sulfonic acids, such as octadecyl acid C ₆ C _6-30 alkyl-aryl sulfonic acids (preferably C _8-24 alkyl-aryl sulfonic acids, etc.) such as _-30 alkyl sulfonic acids, octyl benzene sulfonic acids, nonyl benzene sulfonic acids, dodecyl benzene sulfonic acids, or combinations thereof Etc.

  Organic acid salts include alkali metal salts (sodium, potassium, lithium salts, etc.), alkaline earth metal salts (magnesium, calcium salts, etc.), ammonium salts, amine salts (methylamine, ethylamine, dimethylamine, trimethylamine salts, etc.) Alkylamine salts), alkanolamine salts (monoethanolamine, diethanolamine, triethanolamine, dimethylaminoethanolamine salts, etc.), or combinations thereof. The salt of the organic acid is usually an alkali metal salt (particularly sodium salt) or an alkaline earth metal salt (particularly calcium salt).

  An organic acid or a salt thereof is also mixed, for example, in the production process of the rubber-containing vinyl polymer. However, the presence of the organic acid causes a direct gas generation and decreases the weldability of the resin member. The content of the organic acid may be reduced by purifying the resin composition or the raw material resin, but may be reduced by adjusting the method for producing the raw material resin. For example, when a rubber-containing vinyl polymer is produced by emulsion polymerization, a rubber-containing vinyl polymer produced by bulk polymerization is used because an organic acid derived from a solvent, a surfactant, or the like used for polymerization is mixed. Is preferred.

[Resin molding]
The resin molded body of the present invention is composed of the resin composition for laser welding, and may be used as a member that transmits laser light (transmitting member), or as a member that absorbs laser (absorbing member). May be used. Since the resin molding of the present invention is excellent in laser transmittance, it is usually used as at least a transmitting member.

  The transmittance of the resin molded body with respect to the laser beam is, for example, 10 in the thickness direction of the molded body having a thickness of 4 mm, depending on the oscillation wavelength of the laser beam to be used (for example, a wavelength selected from the range of 740 to 1600 nm). It may be about -100%, for example, 12-100%, preferably 15-100% (for example, 18-98%), more preferably about 20-100% (especially 30-97%).

  Further, in the resin composition of the present invention, even when a flame retardant is contained, the laser beam transmittance can be maintained at a high level. For example, in the resin composition, the laser beam transmittance retention rate R (%) represented by the following formula: Is, for example, 50% or more (for example, about 55 to 100%), preferably 60% or more (for example, about 65 to 99%), more preferably 70% or more (for example, about 75 to 98%), particularly 80 % Or more (for example, about 85 to 97%).

R (%) = (T2 / T1) × 100
(In the formula, R is a laser beam transmission retention rate, and T1 is a resin composition that does not contain a flame retardant (C) (or a resin composition that does not contain a flame retardant (C) and is composed of a vinyl polymer (A)). The transmittance (%) with respect to the laser beam in the thickness direction of the molded product having a thickness of 4 mm, T2 is a resin composition containing a flame retardant (C) (that is, a vinyl polymer (A) and a flame retardant (C). The transmittance (%) with respect to the laser beam in the thickness direction of the molded product having a thickness of 4 mm is shown.)

  The transmittance T2 (that is, the laser beam transmittance of the resin composition containing the flame retardant (C)) depends on the oscillation wavelength of the laser beam to be used (for example, a wavelength selected from the range of 740 to 1600 nm). For example, in the thickness direction of a molded body having a thickness of 4 mm, it can usually be selected from a range of 10% or more (for example, about 10 to 100%), for example, 12 to 99% (for example, 13 to 98%), preferably It is 15 to 97% (for example, 16 to 96%), more preferably 18 to 95%, particularly 20% or more (for example, about 22 to 95%).

  Furthermore, the resin composition of the present invention (or the resin molded product or the first resin molded product) containing the flame retardant (C) is excellent in flame retardancy. For example, when measured at a thickness of 1.5 mm, UL94 Based on the flame retardancy grade, for example, V-2 or higher, preferably V-1 or higher, more preferably V-0 or higher.

  Such a resin molding includes a rubber-containing vinyl polymer (A), a rubber-free vinyl polymer (B), and other components (fillers, colorants, flame retardants (C), if necessary, Other thermoplastic resins, etc.) are mixed (for example, melt-kneaded) by a conventional mixing method using an extruder, kneader, mixer, roll, etc., and then a conventional molding method such as injection molding, extrusion molding, compression molding. It can be obtained by molding by blow molding or the like.

  The shape of the resin molded body is not particularly limited as long as it has at least part of a contact surface (such as a flat surface) sufficient for bonding, and may be a two-dimensional shape (for example, a plate shape) or a three-dimensional shape. Good.

  The thickness of the resin molded body (at least the thickness of the laser welding position of the transmitting member) is, for example, 50 μm to 10 mm, preferably 70 μm to 8 mm, more preferably 100 μm, depending on the application and the laser light transmission or absorption. It may be about ˜5 mm.

[Composite molded body]
In the composite molded body of the present invention, the first molded body (joined body) composed of the resin composition and the second molded body (joined body) composed of a thermoplastic resin are irradiated with laser light. It is joined by. As described above, since the joined body composed of the resin composition is excellent in laser transmittance, it is usually used as a transmissive member, and a joined body composed of a thermoplastic resin is used as an absorbing member. .

  The thermoplastic resin in the bonded body is not particularly limited as long as it can be bonded (or attached) to the bonded body by irradiation with laser light, and various thermoplastic resins can be used.

Examples of the thermoplastic resin include polyamide resins (polyamide 5, polyamide 6, polyamide 66, polyamide 610, polyamide 11, polyamide 12, polyamide 612, polyamide 6/66, polyamide 6/11, and other aliphatic polyamide resins; Aromatic polyamide resins such as polyamide 6T, polyamide 9T, polyamide MXD; alicyclic polyamide resins, etc., polyester resins (poly C _2-4 alkylene terephthalate, poly C _2-4 alkylene naphthalate, copolyesters thereof) , Polyarylate, liquid crystalline polyester, etc.), polycarbonate resin (bisphenol A polycarbonate such as bisphenol A polycarbonate, hydrogenated bisphenol polycarbonate, etc.), olefin resin [polyethylene (Including low-density polyethylene, high-density polyethylene, etc.), polypropylene, ethylene-propylene copolymers, olefin homo- or copolymers (including elastomers) such as ethylene-propylene rubber], styrene resins [polystyrene (GPPS, etc.) ), Styrene-acrylic copolymer (styrene- (meth) acrylic acid copolymer, AS resin, MS resin, etc.), styrene-diene or olefin copolymer (styrene-butadiene-styrene (SBS) block copolymer) Polymer, styrene-isoprene-styrene (SIS) block copolymer, etc.), rubber-containing styrene resin (HIPS, ABS resin, AXS resin (ASA resin, AES resin, etc.), MBS resin etc.), etc.], acrylic resin ( For example, poly (such as polymethyl methacrylate) (Meth) acrylic acid alkyl ester), vinyl resin (vinyl chloride resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, etc.), polyphenylene oxide resin [polyphenylene Oxide, modified polyphenylene oxide (blend with polystyrene, polyphenylene oxide grafted with polystyrene, etc.) and the like. These resins can be used alone or in combination of two or more. The thermoplastic resin constituting the resin molded body may be a crystalline resin or an amorphous resin.

  Among the thermoplastic resins, polyamide resins, polyester resins, polycarbonate resins, olefin resins, styrene resins, acrylic resins, vinyl resins, and polyphenylene oxide resins [particularly polyamide resins (such as polyamide 6) Aliphatic polyamide resins, etc.), olefin resins (polypropylene, ethylene-propylene copolymers and other olefin homo- or copolymers), styrene resins (rubber-containing styrene resins such as ABS resins), acrylics, etc. Resin (such as polymethyl methacrylate)] is preferred. Furthermore, from the point of affinity with the joined body, a styrene resin, an acrylic resin, or a combination thereof, particularly the laser welding resin composition is preferable.

  The joined body may contain a laser light absorbent and / or a colorant. In particular, when the member to be joined is used as an absorbing member and is laser transmissive (for example, when the resin composition for laser welding of the present invention is used), a thermoplastic resin, a laser light absorber and / or a colorant. And a laser absorbing ability may be imparted in combination.

  As the laser light absorber, for example, black pigments such as carbon black (for example, acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, etc.), titanium black, and black iron oxide may be used. Many. These laser light absorbers can be used alone or in combination of two or more. Moreover, these laser light absorbers may be added as a colorant. The average particle diameter of the black pigment can be selected from a wide range of about 10 nm to 3 μm (preferably 10 nm to 1 μm), for example. The average particle diameter of carbon black may be, for example, about 10 to 100 nm, preferably about 15 to 90 nm. The ratio of the laser light absorber is 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin constituting the joined body. It may be about parts by weight.

  Examples of the colorant include various inorganic or organic dyes and pigments used for coloring of resins, such as white dyes (such as titanium white), yellow dyes (such as benzidine yellow), and orange dyes (such as Hansa Yellow). ), Red dye pigment (organic pigment such as lake red), blue dye pigment (organic pigment such as phthalocyanine blue), green dye pigment (organic pigment such as phthalocyanine green), and the like. The ratio of the colorant is not particularly limited, and is, for example, 0 to 10 parts by weight (for example, 0.001 to 10 parts by weight), preferably about 0.01 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin. It may be.

  The joined body may contain the same conventional additive as the laser welding resin composition, if necessary. For example, the joined body may contain a flame retardant. In addition, the flame retardant contained in a to-be-joined body (or 2nd resin molding) is not limited to the said flame retardant (C), A conventional flame retardant (for example, antimony compound etc.) may be sufficient.

  The composite can be obtained, for example, by a method of joining the first molded body composed of the resin composition and the second molded body composed of a thermoplastic resin by irradiating with laser light. . More specifically, the composite molded body is formed by joining a joined body (for example, a transmissive member) and a body to be joined (for example, an absorbing member) by bringing at least a joint portion between the surfaces into contact with each other and irradiating a laser beam. It is obtained by partially melting the interface between the body and the body to be joined, bringing the joint surfaces into close contact, and cooling to join (or integrate).

  As a laser light source used for welding, a laser light source having an oscillation wavelength of about 193 to 1600 nm can be used. In many cases, a laser (630 to 1550 nm), a titanium sapphire laser (Nd: YAG excitation, 690 to 1000 nm), or the like is used.

  In the present invention, the ratio of the organic acid or salt thereof in the resin composition composed of the vinyl polymer (A) containing a rubber component is 10000 ppm or less [for example, 5000 ppm or less, preferably 2000 ppm or less, more preferably 500 ppm. The following (particularly 100 ppm or less)] is applied to the laser irradiation of the first molded body composed of the rubber-containing vinyl polymer (A) and the second molded body composed of a thermoplastic resin. Can improve the bondability.

  The laser welding resin composition, molded product and composite molded product of the present invention are used for home or office automation (OA) equipment such as computers, word processors, printers, copiers, fax machines, telephones, mobile devices (cell phones, Components such as personal digital assistants (PDAs) and household appliances (TVs, VCRs, DVD (Digital Versatile Disc) players, air conditioners, refrigerators, washing machines, etc.) (housings, cases, covers, doors) In addition to cartridges (ink cartridges, toner cartridges, etc.), it is useful in applications such as automobile parts, household goods, and building materials.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the content of the symbol of each component used by the Example and the comparative example, and the evaluation method of each evaluation item are as follows.

[Each component of resin molding]
ABS1: ABS resin, polymer obtained by bulk polymerization method, rubber type: polybutadiene, rubber content 18% by weight, copolymerization ratio of monomer components constituting the matrix: styrene / acrylonitrile = 77/23 (weight ratio), rubber Weight average particle size 500 nm
ABS2: ABS resin, polymer obtained by bulk polymerization method, rubber type: polybutadiene, rubber content 20% by weight, copolymerization ratio of monomer components constituting the matrix: styrene / acrylonitrile = 77/23 (weight ratio), rubber Weight average particle size 1300nm
ABS3: polymer obtained by emulsion polymerization method, salt coagulated product, rubber type: polybutadiene and styrene-butadiene copolymer, rubber content 40% by weight, copolymerization ratio of monomer components constituting the matrix: styrene / acrylonitrile = 74 / 26 (weight ratio), rubber weight average particle diameter 350 nm
ABS4: Polymer obtained by emulsion polymerization, acid coagulated product, rubber type: polybutadiene and styrene-butadiene copolymer, rubber content 40% by weight, copolymerization ratio of monomer components constituting the matrix: styrene / acrylonitrile = 74 / 26 (weight ratio), rubber weight average particle diameter 350 nm
ABS5: polymer obtained by emulsion polymerization, acid coagulated product, rubber type: polybutadiene, rubber content 40% by weight, copolymerization ratio of monomer components constituting the matrix: styrene / acrylonitrile = 73/27 (weight ratio), Rubber weight average particle size 190nm
AS: AS resin, copolymerization ratio of monomer components constituting the matrix: styrene / acrylonitrile = 73/27 (weight ratio), solution viscosity ηsp / c (4 mg / ml chloroform solution, 25 ° C.): 0.85
PC: Polycarbonate resin (made by Idemitsu Kosan Co., Ltd., trade name “Taflon FN2700”)
HI: impact resistant polystyrene (trade name “XL-1” manufactured by Toyo Styrene Co., Ltd.)
FR1: 2,4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine (manufactured by Daiichi FAR Co., Ltd., trade name “SR-245”)
FR2: resorcinol bis [di (2,6-xylyl) phosphate] (manufactured by Daihachi Chemical Industry Co., Ltd., trade name “PX-200”).

[Transmittance of laser light]
A test piece having a thickness of 4 mm was prepared, and a set of 60φ integrating balls for ultraviolet-visible-near infrared region was set in a spectrophotometer (U-3410, manufactured by Hitachi, Ltd.), and a wavelength λ = 840 nm. The transmittance was measured and evaluated according to the following criteria.

○: 30% or more Δ: 20% or more and less than 30% ×: less than 20%

[Organic acid concentration]
A sample (pellet) of 20 mg was precisely weighed and heated at 250 ° C. for 10 minutes to trap the gas generated by a −50 ° C. collection tube, and then regasified at a Curie point. The regasified sample was injected into a gas chromatography analyzer [analytical instrument: Hewlett Packard, HP5890II type, detector: hydrogen flame ionization detector (FID)]. The total amount of organic acid (or its salt) was measured (unit: ppm (μg / g)).

(Measurement condition)
Oven: 100 ° C, 5 minutes
100-240 ° C (temperature rise at 10 ° C / min)
Detector: 300 ° C.

[Flame retardance]
Flame retardance (combustibility) was evaluated based on UL94 with a test piece thickness of 1.5 mm.

[Weldability]
After laser welding, using a tensile tester (Orientec Co., Ltd., Tensilon UCT-1T), each of the absorbing member and the transmissive member is centered on the joint at a chuck distance of 80 mm and a head speed of 5 mm / min. Then, it was pulled outward and the broken state was visually observed and evaluated according to the following criteria.

○: Bonding strength is high and breaks at a portion other than the weld surface. Δ: Bond strength is slightly low and breaks at the weld surface and portions other than the weld surface. ×: Bond strength is low and breaks at the weld surface.

[Amount of generated gas]
At the time of laser welding, the amount of gas generated from the joint between the laser light absorbing member and the laser light transmitting member was evaluated visually according to the following criteria.

○: Less △: Slightly more ×: More

[Shock resistance]
A test piece was prepared in accordance with ISO 179 / 1eA using pellets of the obtained resin composition. Both ends of the test piece were supported and subjected to a Charpy impact tester to measure impact strength (kJ / m ² ).

Examples 1-12 and Comparative Examples 1-3
After mixing with a tumbler mixer at the blending ratio shown in Table 1 or Table 2, it was melt-kneaded at a cylinder temperature of 230 ° C. (maximum value) using a twin screw extruder (manufactured by Nippon Steel Works, Ltd., TEX30α). And pelletized. The obtained pellets are injection-molded at a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C., so that a resin molded body (three-stage plate, length 90 mm × width 50 mm × thickness 1, 2 and 3 mm) (laser light transmitting member) Was molded. Furthermore, using the resin composition containing 0.5% by weight of carbon black based on the whole composition in the resin composition having the composition shown in Table 1 or Table 2, the same size and shape as those of the molded body The laser light absorbing member was molded.

  A laser beam transmitting member is placed on the black colored laser beam absorbing member, and a transparent glass plate is placed on the transmitting member as a weight. ) Were used to weld (welding conditions: output 15 W and scanning speed 10 mm / second). The absorption-side three-stage plate and the transmission-side three-stage plate were overlapped, and the laser beam was irradiated to a position where both the transmission member and the absorption member had a thickness of 2 mm. Tables 1 and 2 show the results of evaluating the properties of the obtained composite molded body. In Table 2, T1 is the laser beam transmittance of the thermoplastic resin (that is, the laser beam transmittance of the thermoplastic resin itself containing no flame retardant), and R is the laser beam transmittance of the resin composition (resin composition containing the flame retardant). Retention rate is shown.

  As is apparent from the table, in the examples, composite molded bodies having high weldability and high impact resistance are produced without generating gas. On the other hand, in Comparative Examples 1 and 2, the weldability is low and the generation of gas is large. In Comparative Example 3, the impact resistance is low. Further, in the resin molded bodies of Examples 8 to 12, since a specific flame retardant is used and the concentration of the organic acid or the salt thereof in the resin composition is remarkably reduced, the generation of gas is suppressed and the design property is reduced. In addition to having excellent resin properties, the transmittance and weldability were high, and the flame retardancy was also high.

Claims (14)

In a composite molded body in which a first molded body that is a member that transmits laser light and a second molded body that is made of a thermoplastic resin are joined by laser light irradiation, the first molded body A laser welding resin composition for constituting a body,
Consists of a vinyl polymer containing a rubber component (A), and the ratio of organic acid or a salt thereof contained in the resin composition Ri der less 6500 ppm,
Rubber-grafted styrenic resin in which the vinyl polymer (A) containing a rubber component contains at least one selected from an acrylic monomer and a vinyl cyanide monomer as a constituent unit, and / or impact resistance Resin composition that is a functional polystyrene and has a rubber component content of 3 to 60% by weight and a rubber component weight average particle size of 230 to 3000 nm in the vinyl polymer (A).   The resin composition according to claim 1, wherein the ratio of the rubber component contained in the resin composition is 3 to 50% by weight. The organic acid or a salt thereof is at least one organic acid selected from a C _6-30 saturated or unsaturated aliphatic carboxylic acid, a terpenic acid and an organic sulfonic acid having a C _6-30 alkyl group, or a salt thereof. 1. The resin composition according to 1.   The resin composition according to claim 1, wherein the rubber-containing vinyl polymer (A) is a resin obtained by a bulk polymerization method.   The resin composition according to claim 1, further comprising a rubber-free styrene resin (B) containing at least one selected from an acrylic monomer and a vinyl cyanide monomer as a constituent unit.   The resin composition according to claim 1, wherein the ratio of the rubber component in the resin composition is 5 to 30% by weight, and the ratio of the organic acid or a salt thereof is 5000 ppm or less.   The resin composition according to claim 1, further comprising at least one flame retardant (C) selected from a halogenated (iso) cyanuric acid ester (C1) and an aromatic condensed phosphoric acid ester (C2).   The resin composition according to claim 7, wherein the halogenated (iso) cyanuric acid ester (C1) is tri (haloaryl) cyanurate.   (I) When measured at a thickness of 1.5 mm, the flame retardant grade based on UL94 is V-2 or higher, and (ii) the laser beam transmittance is 10% or higher in the thickness direction of a molded body having a thickness of 4 mm. The resin composition according to claim 7. The resin composition according to claim 7, wherein the laser beam transmission retention R (%) represented by the following formula is 50% or more.
R (%) = (T2 / T1) × 100
(In the formula, R is the laser beam transmission retention rate, T1 is the transmittance (%) with respect to the laser beam in the thickness direction of the molded product having a thickness of 4 mm of the resin composition not containing the flame retardant (C), and T2 is the flame retardant (C). The transmittance (%) with respect to the laser beam in the thickness direction of the molded product having a thickness of 4 mm of the resin composition containing s.   The molded object comprised with the resin composition of Claim 1.   A composite molded body in which a first molded body composed of the resin composition according to claim 1 and a second molded body composed of a thermoplastic resin are joined together by laser light irradiation.   The method to join the 1st molded object comprised with the resin composition of Claim 1 and the 2nd molded object comprised with the thermoplastic resin by irradiating a laser beam. A method for improving bondability by laser irradiation between a first molded body composed of a vinyl polymer (A) containing a rubber component and a second molded body composed of a thermoplastic resin, The first molded body is a member that transmits laser light, and the vinyl polymer (A) containing the rubber component is selected from an acrylic monomer and a vinyl cyanide monomer. In the vinyl polymer (A), which is a rubber-grafted styrene resin and / or impact-resistant polystyrene containing at least one kind as a structural unit, the rubber component content is 3 to 60% by weight. And the weight average particle diameter of a rubber component is 230-3000 nm, and the ratio of the organic acid or its salt in the resin composition comprised by the said rubber-containing vinyl polymer (A) shall be 6500 ppm or less. Good way.