Polybutylene terephthalate resin composition for silicone adhesion, and molded article and composite molded article made therefrom

Abstract

To provide a polybutylene terephthalate resin composition for silicone adhesion that all achieves silicone adhesiveness with addition reaction-type silicone rubber and condensation reaction type silicone rubber, fluidity and releasability while maintaining the impact resistance and mechanical strength required for electrical and electronic equipment component, automobile component, machine component or the like, and to provide a molding made of the same, and a composite molding including silicone adhesive layer.SOLUTION: Provided is a polybutylene terephthalate resin composition for silicone adhesion in which (A) a polybutylene terephthalate resin, (B) a glycidyl group-containing olefin-based elastomer, (C) a fibrous reinforcing material, and (D) a fatty acid ester compound are incorporated.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polybutylene terephthalate resin composition that has the fluidity and releasability required for the production of electrical and electronic equipment parts, automobile parts, machine parts, etc., and also has adhesiveness with silicone-based adhesives. [Background technology]

[0002] Polybutylene terephthalate resin (hereinafter sometimes abbreviated as PBT resin) has excellent heat resistance, chemical resistance, electrical properties, dimensional stability, and other properties, and also has good processability, so it is widely used as a material for manufacturing various electrical and electronic equipment components, vehicle components for automobiles, trains, electric trains, and other general industrial products.

[0003] In particular, for electronic components such as electronic substrates, connector members, and sensor components that are vulnerable to external impacts and the intrusion of moisture, engineering plastics are often used as case or cover materials for the components, and polybutylene terephthalate resin, which has excellent properties as an engineering plastic, is often used as a case or cover material for the above-mentioned components.

[0004] In such applications, it is common to integrate plastic parts together, or metal or glass parts, to house electronic components and protect the internal components, and a variety of joining and bonding methods are used.

[0005] In particular, the method of producing a composite molded product using an adhesive is simple and can be used regardless of the shape of the part, and can also improve airtightness as a potting material, so it is widely used in various fields. Examples of adhesives and potting materials include epoxy resins, urethane resins, and silicone rubber, and silicone rubber is widely used, especially for parts installed in automobiles, due to its ease of handling and vibration absorption properties.

[0006] In applications where this method is applied, the plastic used as the case itself must have mechanical strength and impact resistance, so materials modified with elastomers or various additives are used. These modifiers can have a negative effect on the adhesion and bonding with silicone rubber, which can cause poor adhesion between the plastic and the adhesive.

[0007] To address these problems with adhesion between plastics and adhesives, a conventional method for improving the adhesion has been proposed, as described in Patent Document 1, in which a glycidyl group-containing acrylic elastomer and glass fiber are added to polybutylene terephthalate to improve adhesion with an addition reaction type silicone adhesive.

[0008] Furthermore, Patent Document 2 discloses a technique in which polybutylene terephthalate contains a specific silicon compound, an antioxidant, a release agent, and a polyester-based elastomer to improve adhesion with an addition reaction type silicone adhesive. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent Publication No. 2007-91842 [Patent Document 2] Japanese Patent Application Publication No. 10-316844 Summary of the Invention [Problem to be solved by the invention]

[0010] As mentioned above, when manufacturing composite molded products using silicone rubber, plastic materials for cases and covers that house electronic components, etc., require silicone adhesiveness in addition to mechanical strength and impact resistance. Furthermore, in recent years, especially for automotive parts, cases and covers have been made thinner to reduce the weight of parts, and materials with poor fluidity and releasability can cause poor filling during molding or deformation when released from the mold.

[0011] Thus, plastic materials for composite molded products, including silicone adhesives and potting materials, are required to have a high degree of silicone adhesion, impact resistance, mechanical strength, fluidity, and releasability. However, in the technology described in Patent Document 1, the specific structure of the elastomer blended with polybutylene terephthalate significantly reduces fluidity, and releasability was not considered, making it unsuitable for practical use. In addition, adhesion to condensation reaction type silicone adhesives, which are widely used in general, was not considered, leaving room for further study. In addition, the technology specifically disclosed in the examples of Patent Document 2 did not satisfy the mechanical strength and heat resistance required for the above-mentioned case / cover applications. Furthermore, by containing silicone oil, which is also commonly used as a release agent as a specific silicon compound, adhesion to addition type silicone adhesives was improved, but there was a problem that it was not effective with condensation reaction type silicone adhesives. In addition, it is generally known that sulfur-based compounds and phosphorus compounds deactivate the platinum compound, which is a curing catalyst contained in addition reaction type silicone adhesives, and cause reaction inhibition, and the resin composition of Patent Document 2 was unsuitable for practical use.

[0012] Therefore, the present invention has an objective of solving the above-mentioned problems and providing a polybutylene terephthalate resin composition for silicone adhesion which maintains the impact resistance and mechanical strength required for plastic materials for cases and covers while achieving a high level of silicone adhesion, fluidity and releasability with addition reaction type and condensation reaction type silicone rubbers, as well as a molded article made of this polybutylene terephthalate resin composition and a composite molded article including a silicone adhesive layer. [Means for solving the problem]

[0013] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by blending (A) a polybutylene terephthalate resin, (B) a specific olefin-based elastomer, (C) a fibrous reinforcing material, and (D) a fatty acid ester compound, and have arrived at the present invention. That is, the present invention has the following configuration.

[0014] That is, the present invention provides This is a polybutylene terephthalate resin composition for silicone adhesion, which is obtained by blending 100 parts by weight of (A) polybutylene terephthalate resin with 3 to 50 parts by weight of (B) an olefin-based elastomer containing a glycidyl group, 15 to 150 parts by weight of (C) a fibrous reinforcing material, and 0.05 to 3 parts by weight of (D) a fatty acid ester compound. Effect of the Invention

[0015] According to the polybutylene terephthalate resin composition of the present invention, a polybutylene terephthalate resin composition for silicone adhesion is provided, which maintains the impact resistance and mechanical strength required for electric / electronic device parts, automobile parts, machine parts, etc., while achieving a high level of silicone adhesion, fluidity, and releasability with addition reaction type silicone rubber and condensation reaction type silicone rubber. The polybutylene terephthalate resin composition of the present invention is useful as a case or cover material for housing electronic parts, etc., by silicone adhesion and / or silicone potting. Furthermore, molded products made of the polybutylene terephthalate resin composition of the present invention are useful as composite molded products formed by silicone adhesion and / or silicone potting, regardless of the type of silicone adhesive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present invention will be described in detail, however, the present invention is not limited to the following embodiments and can be practiced with appropriate modifications within the scope of the object of the present invention.

[0017] The polybutylene terephthalate resin composition of the present invention, which is a blend of (A) polybutylene terephthalate resin, (B) olefin-based elastomer containing a glycidyl group, (C) fibrous reinforcing material, and (D) fatty acid ester compound, contains a reaction product of the individual components constituting the resin composition, but since the reaction product is produced by a complex reaction between polymers, there are circumstances in which it is not practical to specify its structure. Therefore, the present invention is specified by the blended components.

[0018] (A) Polybutylene terephthalate resin The polybutylene terephthalate resin (A) constituting the present invention is a polymer obtained by a normal polymerization method such as polycondensation reaction using terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative as the main components. It may contain other copolymerization components within a range that does not impair its properties, for example, about 20 parts by weight or less. Preferable examples of these polymers and copolymers include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate), poly(butylene / ethylene) terephthalate, etc., which may be used alone or in combination of two or more kinds.

[0019] The method for producing the polybutylene terephthalate resin (A) used in the present invention is not particularly limited, and known polycondensation methods and ring-opening polymerization methods can be used. Either a batch polymerization method or a continuous polymerization method can be used, and either a method involving transesterification and polycondensation reactions, or a method involving polycondensation by direct polymerization (direct polymerization method) can be applied. The continuous polymerization method is preferred because it can reduce the amount of carboxyl terminal groups and has a large effect of improving fluidity, and the direct polymerization method is preferred from the viewpoint of cost. In addition, in order to effectively advance the esterification reaction or the transesterification reaction and the polycondensation reaction, it is preferable to add a catalyst during these reactions. Specific examples of the catalyst include organotitanium compounds such as methyl ester, tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl ester, tetraisobutyl ester, tetra-tert-butyl ester, cyclohexyl ester, phenyl ester, benzyl ester, tolyl ester, or mixed esters of titanic acid, dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, cyclohexahexylditin oxide, didodecyltin oxide, and triethyltin hydride. Examples of the catalyst include tin compounds such as tin oxide, triphenyltin hydroxide, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin dichloride, tributyltin chloride, dibutyltin sulfide, butylhydroxytin oxide, alkylstannoic acids such as methylstannoic acid, ethylstannoic acid, and butylstannoic acid, zirconia compounds such as zirconium tetra-n-butoxide, and antimony compounds such as antimony trioxide and antimony acetate. Two or more of these catalysts can be used in combination. From the viewpoint of the amount of carboxyl groups in the polybutylene terephthalate (A), among these polymerization catalysts, organic titanium compounds and tin compounds are preferred, and tetra-n-butyl ester of titanic acid is more preferred. The amount of the polymerization catalyst added is preferably in the range of 0.01 to 0.2 parts by weight relative to 100 parts by weight of the polybutylene terephthalate resin.

[0020] The amount of carboxyl groups in the polybutylene terephthalate resin (A) used in the present invention is preferably 20 eq / t or less, more preferably 15 eq / t or less, in order to suppress hydrolysis of polybutylene terephthalate. The lower limit of the amount of carboxyl groups is about 0 eq / t. Here, the amount of carboxyl groups in the polybutylene terephthalate resin (A) is a value measured by dissolving the polybutylene terephthalate resin (A) in an o-cresol / chloroform solvent and then titrating with ethanolic potassium hydroxide.

[0021] (B) Olefin-based elastomer containing glycidyl groups The olefin-based elastomer containing a glycidyl group (hereinafter sometimes abbreviated as (B) elastomer) used in the present invention is preferably a glycidyl group-containing copolymer containing an α-olefin and a glycidyl ester of an α,β-unsaturated acid as copolymerization components, and a glycidyl group-containing copolymer containing an α-olefin, an α,β-unsaturated acid or a derivative thereof, and a glycidyl ester of an α,β-unsaturated acid as copolymerization components. From the viewpoint of fluidity, it is more preferable to use one containing an α,β-unsaturated acid or a derivative thereof as a copolymerization component.

[0022] Examples of α-olefins include ethylene, propylene, 1-butene, 1-pentene, and 1-octene. Two or more of these may be used. Examples of glycidyl esters of α,β-unsaturated acids include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycidyl itaconate. Two or more of these may be used. Glycidyl methacrylate is preferably used. Examples of α,β-unsaturated acids or derivatives thereof include vinyl esters such as vinyl acetate and vinyl propionate, and acrylic and methacrylic acid esters such as methyl, ethyl, propyl, and butyl. Two or more of these may be used. From the viewpoint of silicone adhesion and fluidity, α,β-unsaturated carboxylic acid alkyl esters are preferred.

[0023] Specific examples of olefin-based elastomers containing glycidyl groups include ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl acrylate copolymer, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / glycidyl methacrylate copolymer, ethylene / butyl acrylate / glycidyl methacrylate copolymer, ethylene / glycidyl methacrylate-g-polymethyl methacrylate, ethylene / glycidyl methacrylate-g-polystyrene, and ethylene / glycidyl methacrylate-g-acrylonitrile / styrene. These may be used alone or in combination of two or more.

[0024] From the viewpoint of adhesion, fluidity, and releasability with addition reaction type silicone adhesives and condensation reaction type silicone adhesives, ethylene / glycidyl methacrylate copolymers and ethylene / alkyl acrylate / glycidyl methacrylate copolymers are preferred, and ethylene / alkyl acrylate / glycidyl methacrylate copolymers are more preferred. These compounds are available, for example, under the trade names "Bondfast" (registered trademark) from Sumitomo Chemical Co., Ltd. and "Rotader" (registered trademark) from Arkema Co., Ltd.

[0025] From the viewpoint of adhesion to addition reaction type silicone adhesives and condensation reaction type silicone adhesives, the copolymerization component containing a glycidyl group contained in the (B) elastomer is desirably 2 parts by weight or more of the total copolymerization components, preferably 5 parts by weight or more, and more preferably 7 parts by weight or more. The more the copolymerization component containing a glycidyl group contained in the (B) elastomer is, the lower the fluidity becomes, so the upper limit is preferably 20 parts by weight or less, and more preferably 12 parts by weight or less. Furthermore, by using an elastomer containing an acrylic acid alkyl ester as a copolymerization component, even when the glycidyl group content is increased, the fluidity is not impaired and even better silicone adhesion can be achieved.

[0026] As an elastomer containing a glycidyl group and not containing an α-olefin, which does not fall under (B), an elastomer having a multilayer structure in which an acrylic elastomer containing an acrylic acid alkyl ester is used as a core layer and a vinyl copolymer containing a glycidyl group is used as a shell layer, is generally used. However, because of its specific structure, there is a problem that the fluidity during molding is reduced, and therefore it is not preferable in practice.

[0027] The blending amount of (B) olefin-based elastomer containing a glycidyl group is 3 to 50 parts by weight, preferably 6 to 40 parts by weight, and more preferably 6 to 30 parts by weight, per 100 parts by weight of (A) polybutylene terephthalate resin of the present invention, from the viewpoints of silicone adhesion, impact resistance, and fluidity. If the blending amount is less than 3 parts by weight, the impact resistance of the polybutylene terephthalate resin composition is inferior, and if it exceeds 50 parts by weight, the silicone adhesion and fluidity are reduced.

[0028] (C) Fibrous reinforcement The (C) fibrous reinforcing material used in the present invention may be glass fiber, wollastonite, potassium titanate whisker, zinc oxide whisker, carbon fiber, alumina fiber, metal fiber, and organic fiber (nylon, polyester, aramid, polyphenylene sulfide, liquid crystal polymer, acrylic, etc.). By using the (C) fibrous reinforcing material, mechanical properties and impact resistance can be further improved. Although it is possible to use one or more types of fibrous reinforcing materials in combination, it is preferable to use glass fiber or wollastonite.

[0029] In order to improve the adhesion at the interface between the polybutylene terephthalate resin (A) of the present invention and the fibrous reinforcing material (C), it is preferable to treat the surface of the fibrous reinforcing material (C) with a surface treatment agent such as a bundling agent. As the surface treatment agent, glass fibers treated with a bundling agent containing a silane coupling agent such as an aminosilane compound or an epoxysilane compound, a copolymer of acrylic acid such as urethane, an acrylic acid / styrene copolymer, a copolymer of maleic anhydride such as methyl acrylate / methyl methacrylate / maleic anhydride copolymer, vinyl acetate, or one or more epoxy compounds such as a bisphenol-type epoxy or a novolac-type epoxy compound are preferably used. As the surface treatment agent, a fibrous reinforcing material surface-treated with a bisphenol-type epoxy compound and / or a novolac-type epoxy compound is preferable in terms of hydrolysis resistance, impact resistance, and mechanical properties.

[0030] The fiber diameter of the fibrous reinforcing material is preferably in the range of 1 to 30 μm. From the viewpoint of dispersibility of the glass fiber in the resin, the lower limit is preferably 5 μm. From the viewpoint of mechanical properties, the upper limit is preferably 15 μm.

[0031] The blending amount of the (C) fibrous reinforcing material is 15 to 150 parts by weight, preferably 20 to 130 parts by weight, and more preferably 30 to 100 parts by weight, based on 100 parts by weight of the (A) polybutylene terephthalate resin of the present invention, from the viewpoints of mechanical properties and impact resistance. If the blending amount is less than 15 parts by weight, the mechanical properties of the polybutylene terephthalate resin composition are inferior, and if it exceeds 150 parts by weight, the moldability is reduced, which is not preferable.

[0032] In addition, a non-fibrous filler can be used in combination for the purpose of improving the dimensional stability of the molded product, etc. Examples of such non-fibrous fillers include zeolite, sericite, kaolin, mica, clay, bentonite, asbestos, talc, silicates such as alumina silicate, metal compounds such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, glass flakes, glass beads, ceramic beads, mica, boron nitride, silicon carbide, and silica.

[0033] (D) Fatty acid ester compound The fatty acid ester compound (D) used in the present invention is composed of an aliphatic alcohol and a fatty acid.

[0034] Examples of the aliphatic alcohol include lauryl alcohol, stearyl alcohol, ethylene glycol, propylene glycol, butylene glycol, glycerol, diglycerol, erythritol, pentaerythritol, sorbitol, triglycerol, dipentaerythritol, and tetraglycerol. These aliphatic alcohols can be used alone or in combination. Preferred aliphatic alcohols are pentaerythritol and dipentaerythritol. Pentaerythritol is particularly preferred.

[0035] The fatty acid is preferably a linear or branched saturated fatty acid having 5 to 30 carbon atoms, such as pentanoic acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and melissic acid, with stearic acid being particularly preferred.

[0036] From the viewpoint of avoiding the transesterification reaction with the polybutylene terephthalate resin (A) and from the viewpoint of heat resistance, the fatty acid ester compound (D) is preferably a full ester that does not substantially contain free hydroxyl groups and carboxyl groups. Thermogravimetric analysis (TGA) is generally used as an index of heat resistance, and the higher the temperature at which a certain weight loss is observed, the more the appearance defects of molded products and mold contamination caused by gas generated during molding are suppressed, which is practically preferable. In consideration of the general molding temperature of PBT resin, it is particularly preferable that the temperature at which the weight is reduced by 10% in TGA measurement is 300°C or higher. Specific examples of the fatty acid ester compound (D) are fatty acid esters composed of monohydric aliphatic alcohols and higher fatty acids, montanic acid esters of ethylene glycol, glycerin tristearate, pentaerythritol tetrastearate, and dipentaerythritol hexastearate. Among them, fatty acid ester compounds composed of trihydric to hexahydric aliphatic alcohols and fatty acids are preferred, and pentaerythritol tetrastearate and dipentaerythritol hexastearate are particularly preferred. Most preferred is pentaerythritol tetrastearate.

[0037] In the present invention, it is necessary to add a release agent to give the molded product obtained by injection molding releasability, but since the release agent exerts its effect by being present on the surface of the molded product, it is important that the adhesiveness is not hindered in applications using silicone adhesive. From the viewpoint of silicone adhesiveness, fatty acid ester compounds are preferred, and pentaerythritol-based compounds having a structure derived from pentaerythritol are particularly preferred. Also, from the viewpoint of releasability, pentaerythritol-based compounds are preferred.

[0038] The (D) fatty acid ester compounds may be used alone or in combination of two or more.

[0039] (D) Fatty acid ester compounds are available, for example, from Emery Oleochemicals Japan Co., Ltd. under the trade name "Roxiol," from ADEKA Corporation under the trade name "Adeka Cizer" (registered trademark), and from Riken Vitamin Co., Ltd. under the trade name "Likestar" (registered trademark).

[0040] In the polybutylene terephthalate resin composition of the present invention, the amount of the fatty acid ester compound (D) is 0.05 to 3 parts by weight, preferably 0.1 to 1.5 parts by weight, based on 100 parts by weight of the polybutylene terephthalate resin (A). If the amount of the fatty acid ester compound (D) is less than 0.05 parts by weight, the mold releasability decreases, and if it exceeds 3 parts by weight, the silicone adhesiveness decreases, which is not preferable.

[0041] [Other ingredients] The polybutylene terephthalate resin composition of the present invention may contain other resin components, antioxidants, stabilizers, crystal nucleating agents, colorants, lubricants, and other conventional additives, as long as the effects of the present invention are not impaired. Two or more of these may be contained. The other resin components may be any resin that is melt-moldable, and examples thereof include AS resin (acrylonitrile / styrene copolymer), hydrogenated or unhydrogenated SBS resin (styrene / butadiene / styrene triblock copolymer), hydrogenated or unhydrogenated SIS resin (styrene / isoprene / styrene triblock copolymer), polycarbonate resin, polyethylene resin, polypropylene resin, polymethylpentene resin, cyclic olefin resin, cellulose resin such as cellulose acetate, polyethylene terephthalate resin, polytrimethylene terephthalate resin, polyamide resin, polyacetal resin, and the like.

[0042] In particular, amorphous resins such as AS resin (acrylonitrile / styrene copolymer) and polycarbonate resin can be easily melt-kneaded with polybutylene terephthalate, and by blending them, molded products with excellent dimensional stability can be produced. From the viewpoint of dimensional stability, AS resin is particularly preferred. When blending such amorphous resins, the preferred blending amount of the amorphous resin is preferably 0 parts by weight or more and 100 parts by weight or less per 100 parts by weight of polybutylene terephthalate resin (A) in order to maintain the function of polybutylene terephthalate resin (A). By making the amount 100 parts by weight or less, it is possible to achieve both silicone adhesiveness and dimensional stability.

[0043] In the present invention, the nucleating agent may be either an inorganic nucleating agent or an organic nucleating agent. Examples of the inorganic nucleating agent include synthetic mica, clay, zeolite, magnesium oxide, calcium sulfide, boron nitride, neodymium oxide, etc., and it is preferable that the inorganic nucleating agent is modified with an organic substance in order to improve dispersibility in the composition. Examples of organic crystal nucleating agents include sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, barium benzoate, lithium terephthalate, sodium terephthalate, potassium terephthalate, sodium toluate, sodium salicylate, potassium salicylate, zinc salicylate, aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthalate, and organic carboxylic acid metal salts such as sodium p-toluenesulfonate and sodium sulfoisophthalate, sorbitol compounds, metal salts of phenylphosphonate, and phosphorus compound metal salts such as sodium-2,2'-methylenebis(4,6-di-t-butylphenyl)phosphate. By blending these crystal nucleating agents, it is possible to obtain a thermoplastic resin composition and molded article having excellent mechanical properties, moldability, heat resistance, and durability.

[0044] In the present invention, any of the stabilizers used for thermoplastic resins can be used as the stabilizer. Specifically, antioxidants, light stabilizers, etc. can be mentioned. By blending these stabilizers, it is possible to obtain a thermoplastic resin composition and a molded product having excellent mechanical properties, moldability, heat resistance, and durability.

[0045] Examples of the antioxidant include phenolic compounds such as 2,6-di-t-butyl-4-methylphenol, tetrakis(methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate)methane, and tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate; sulfur compounds such as dilauryl-3,3'-thiodipropionate and dimyristyl-3,3'-thiodipropionate; and phosphorus compounds such as trisnonylphenyl phosphite and distearyl pentaerythritol diphosphite.

[0046] For example, additives exemplified as antioxidants may also act as stabilizers or ultraviolet absorbing agents. Also, some of the additives exemplified as stabilizers may have antioxidant or ultraviolet absorbing properties. In other words, the above classification is for convenience only and does not limit the functions.

[0047] The method for producing the polybutylene terephthalate resin composition of the present invention is not particularly limited as long as it satisfies the requirements specified in the present invention, and a method of uniformly melt-kneading with a single-screw or twin-screw extruder, or a method of mixing in a solution and then removing the solvent, etc. are preferably used, but from the viewpoint of productivity, a method of uniformly melt-kneading with a single-screw or twin-screw extruder is preferred, and a method of melt-kneading with a twin-screw extruder is more preferred in terms of more uniformly melt-kneading (A) polybutylene terephthalate resin and (B) olefin-based elastomer containing a glycidyl group. Among them, a method of melt-kneading using a twin-screw extruder with L / D>30, where L (mm) is the screw length and D (mm) is the screw diameter, is particularly preferred. The screw length referred to here refers to the length from the position where the raw material is supplied at the base of the screw to the tip of the screw. A larger L / D is desirable because it allows (A) the polybutylene terephthalate resin and (B) the olefin-based elastomer containing glycidyl groups to be thoroughly mixed, improving the mechanical strength and impact resistance of the polybutylene terephthalate resin composition for silicone bonding.

[0048] In addition, in the present invention, when a twin-screw extruder is used for melt-kneading the resin composition, a combination of full flight and kneading disks is preferably used as the screw configuration, but in order to obtain the resin composition of the present invention, uniform kneading by the screw is necessary. Therefore, the ratio of the total length of the kneading disks (kneading zone) to the total length of the screw is preferably in the range of 5 to 50%, more preferably in the range of 10 to 40%.

[0049] In the present invention, when the resin composition is melt-kneaded, a preferred method for feeding each component is to use an extruder having two feeding ports, and feed (A) polybutylene terephthalate resin, (B) olefin-based elastomer containing a glycidyl group, (D) fatty acid ester compound, and other components as necessary through a main feeding port installed at the base of the screw, and feed (C) fibrous reinforcing material through a secondary feeding port installed between the main feeding port and the tip of the extruder, and melt-mix the components.

[0050] The melt kneading temperature during production of the resin composition of the present invention is preferably 190 to 340°C, more preferably 210 to 310°C, and particularly preferably 240 to 290°C, in that excellent moist heat resistance and mechanical properties are obtained.

[0051] The resin composition of the present invention can be molded by any method such as commonly known injection molding, extrusion molding, blow molding, press molding, spinning, etc., and can be processed into various molded products and used. The molded products can be used as injection molded products, extrusion molded products, blow molded products, films, sheets, fibers, etc., the films can be used as various films such as unstretched, uniaxially stretched, and biaxially stretched films, and the fibers can be used as various fibers such as unstretched yarns, stretched yarns, and ultra-stretched yarns.

[0052] In the present invention, the above-mentioned various molded products can be used for various applications such as automobile parts, electric and electronic parts, building materials, various containers, daily necessities, household goods and sanitary products. In particular, in the present invention, by taking advantage of the excellent adhesiveness, fluidity and releasability with silicone adhesives, the molded product obtained by molding the resin composition of the present invention is used for composite molded products obtained by silicone bonding and / or potting other molded products. Examples of other molded products include molded products obtained by molding the resin composition of the present invention, molded products obtained by molding a resin composition different from the resin composition of the present invention, metal parts, glass parts and the like. As metal parts, any metal parts used for engine and exhaust system peripheral parts, motor parts, battery peripheral parts, various electrical parts and the like may be used, and in particular, metal substrates with electronic parts mounted thereon are preferred. In addition, the silicone adhesive used for silicone bonding and / or potting can be any type, and both addition reaction type silicone adhesives and condensation reaction type silicone adhesives can be used. For example, it is suitable for cases and cover materials that are silicone bonded to metal substrates with electronic parts mounted thereon, and for in-vehicle applications, it is particularly suitable for thin-walled cases and cover materials for radar parts, sensor parts, various ECU parts and the like. EXAMPLES

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Raw materials used in each example and comparative example are shown below. (A) Polybutylene terephthalate resin A-1: Polybutylene terephthalate (MFR: 57g / 10min (250℃, 1000gf), carboxyl group concentration: 15eq / t) (B) Olefin-based elastomer containing glycidyl groups Of the total amount of copolymerization components in the elastomer, the amount of copolymerization components containing glycidyl groups is referred to as the GMA amount. B-1: Ethylene / methyl acrylate / glycidyl methacrylate copolymer ("Rotader" (registered trademark) AX8900 (product name) manufactured by Arkema Co., Ltd., GMA content: 8 wt%) B-2: Ethylene / methyl acrylate / glycidyl methacrylate copolymer ("Bondfast" (registered trademark) BF-7M (product name) manufactured by Sumitomo Chemical Co., Ltd., GMA content: 6 wt%) B-3: Ethylene / methyl acrylate / glycidyl methacrylate copolymer ("Bondfast" (registered trademark) BF-7L (product name) manufactured by Sumitomo Chemical Co., Ltd., GMA content: 3 wt%) B-4: Ethylene / glycidyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., "Bondfast" (registered trademark) BF-2C (product name), GMA content: 6 wt%) B'-1: Ethylene / methyl acrylate copolymer (manufactured by Mitsui DuPont Polychemicals, "Elbaloy AC" (registered trademark) 22534 (product name)) B'-2: Glycidyl methacrylate modified acrylic / silicone composite rubber (Mitsubishi Chemical Corporation, Metablen S2200 (product name)) B'-3: Core-shell type rubber, core: butyl acrylate rubber, shell: methyl methacrylate / glycidyl methacrylate copolymer (manufactured by Rohm and Haas Company, "Paraloid" (registered trademark) 2314 (product name)) (C) Fibrous reinforcement C-1: Glass fiber, Nippon Electric Glass Co., Ltd. T-120H (chopped strands, 3 mm long, average fiber diameter 10.5 μm) (D) Fatty acid ester compound D-1: Pentaerythritol tetrastearate ("Roxiol" (registered trademark) VPG861 (product name) manufactured by Emery Oleochemicals Japan Co., Ltd.) (10% weight loss temperature by TGA: 402°C) D-2: Dipentaerythritol hexastearate ("Roxiol" (registered trademark) VPG2571 (product name) manufactured by Emery Oleochemicals Japan Co., Ltd.) (10% weight loss temperature by TGA: 397°C) D-3: Fatty acid ester consisting of ethylene glycol and montanic acid (Licowax E (trade name) manufactured by Clariant Japan Co., Ltd.) (10% weight loss temperature by TGA: 321°C) D-4: Pentaerythritol distearate ("Roxiol" (registered trademark) P728 (product name) manufactured by Emery Oleochemicals Japan Co., Ltd.), (10% weight loss temperature by TGA: 270°C) (D) Compounds other than fatty acid ester compounds D'-1: Amide wax: Kyoeisha Chemical Co., Ltd., Light Amide WH-255 (product name): polycondensate of stearic acid, sebacic acid, and ethylenediamine (10% weight loss temperature by TGA: 350°C) D'-2: Dimethyl silicone oil (viscosity: 300 mm 2 / s) (Silicone adhesive) The silicone adhesive and curing conditions used in the silicone adhesive property evaluation are as follows. Dow Toray Industries, Inc. SE1714 (addition reaction type silicone adhesive) (Curing conditions: 150℃ x 30 minutes) Dow Toray Industries, Inc. SE9185 (condensation reaction type silicone adhesive) (Curing conditions: 23℃ x 50%RH x 168 hours).

[0054] The evaluation methods used in the examples and comparative examples are summarized below.

[0055] (1) Silicone adhesion The pellets obtained in each Example and Comparative Example were dried in a hot air dryer at 130°C for 3 hours, and then a multipurpose test piece A (total length 150 mm, thickness 4 mm) specified in ISO3167:2002 was prepared by injection molding using an SE50DUZ injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., under conditions of a cylinder temperature of 260°C and a mold temperature of 80°C. The obtained multipurpose test piece A was cut into two at the center, and two Teflon (registered trademark) spacers (thickness 0.72 mm) were placed on the end (width 19.5 mm x thickness 4 mm) of one of the test pieces so as to sandwich the adhesive application part, and an adhesive area of ​​width 19.5 mm x length 1 mm x thickness 0.72 mm was secured. A silicone adhesive was applied thereon, and then the other test piece was placed on top of it and treated under the above-mentioned predetermined curing conditions to cure the silicone adhesive. Finally, a tensile test was performed on the silicone-bonded test piece complex at a tensile speed of 5 mm / min to measure the silicone adhesive strength. The higher the silicone adhesive strength, the better the silicone adhesiveness.

[0056] (2) Liquidity (flow length) Pellets of the resin composition having the composition shown in each Example and Comparative Example were dried in a hot air dryer at 130°C for 3 hours or more, and then molded into a rectangular molded product having a thickness of 1 mm and a width of 10 mm using an SE50DUZ injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., and the flowability was evaluated by taking the length of the molded product as the flow length. The injection conditions were a cylinder temperature of 260°C, a mold temperature of 80°C, an injection pressure of 80 MPa, an injection time of 5 seconds, and a cooling time of 5 seconds. The higher the flow length, the better the flowability of the polybutylene terephthalate resin composition can be determined.

[0057] (3) Mold releasability Pellets of the resin composition shown in each Example and Comparative Example were dried for 3 hours or more in a hot air dryer at 130°C, and then a box-shaped molded product (width 30mm x depth 30mm x height 30mm, thickness 1.5mm) with an opening was injection molded using an SE50DUZ injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. under molding conditions of cylinder temperature 260°C, mold temperature 80°C, and cooling time 10 seconds, and the resistance when ejected with an ejector pin was measured as the mold release force. The lower the mold release force, the better the mold releasability.

[0058] (4) Tensile properties (tensile strength) The pellets obtained in each Example and Comparative Example were dried in a hot air dryer at 130°C for 3 hours, and then a multipurpose test piece type A (total length 150 mm, test section width 10 mm, thickness 4 mm) specified in ISO3167:2002 was prepared by injection molding using an SE50DUZ injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., under conditions of a cylinder temperature of 260°C and a mold temperature of 80°C. The tensile strength of the obtained multipurpose test piece type A was measured according to ISO527-1,2:2012. If the tensile strength was 100 MPa or more, it was judged to be graded as A, and if it was less than 100 MPa, it was judged to be graded as B.

[0059] (5) Impact resistance (Charpy impact strength (notched)) The pellets obtained in each Example and Comparative Example were dried in a hot air dryer at 130°C for 3 hours, and then injection molded into ISO3167 Type-IA multipurpose test pieces. Charpy impact test pieces (with notches) measuring 80 mm in length, 10 mm in width, and 4 mm in thickness were cut out from the parallel part of the test pieces. Using these Charpy impact test pieces, the Charpy impact strength (with notches) was measured according to ISO179. The Charpy impact strength was 9.0 kJ / m 2 If it is above 9.0kJ / m, it is rated A. 2 If it was less than this, it was rated as B.

[0060] [Examples 1 to 8] According to the compounding compositions shown in Table 1, components (A), (B), and (D) as well as all other components were fed into the base of a twin-screw extruder, and component (C) was fed into a side inlet located between the main inlet and the tip of the extruder. The mixture was melt-kneaded in a twin-screw extruder with a screw diameter of 37 mmφ (TEM37SS (product name), manufactured by Toshiba Machine Co., Ltd.) and a cylinder temperature set to 260°C.

[0061] The strands discharged from the die were cooled in a cooling bath and then pelletized with a strand cutter. The resulting pellets were used to evaluate silicone adhesion, flowability, releasability, tensile strength, and impact resistance using the above-mentioned evaluation methods. All of the resulting test pieces were excellent in silicone adhesion, flowability, releasability, tensile strength, and impact resistance.

[0062] [Comparative Examples 1 to 9] According to the compounding compositions shown in Table 2, components (A), (B), and (D) as well as all other components were fed into the base of a twin-screw extruder, and component (C) was fed into a side inlet located between the main inlet and the tip of the extruder. The mixture was melt-kneaded in a twin-screw extruder with a screw diameter of 37 mmφ (TEM37SS (product name), manufactured by Toshiba Machine Co., Ltd.) and a cylinder temperature set to 260°C.

[0063] The strands discharged from the die were cooled in a cooling bath and then pelletized with a strand cutter. The resulting pellets were used to evaluate silicone adhesion, flowability, releasability, tensile strength, and impact resistance using the above-mentioned evaluation methods. The resulting test pieces were inferior in any of silicone adhesion, flowability, releasability, tensile strength, and impact resistance.

[0064] [Table 1]

[0065] [Table 2]

Claims

1. A polybutylene terephthalate resin composition for silicone bonding, comprising 100 parts by weight of (A) polybutylene terephthalate resin, 3 to 50 parts by weight of (B) an olefin-based elastomer containing a glycidyl group, 15 to 150 parts by weight of (C) a fibrous reinforcing material, and 0.05 to 3 parts by weight of (D) a fatty acid ester compound.

2. 2. The polybutylene terephthalate resin composition for silicone adhesion according to claim 1, wherein the fatty acid ester compound (D) is a fatty acid ester compound comprising a tri- to hexahydric aliphatic alcohol and a fatty acid.

3. 3. The polybutylene terephthalate resin composition for silicone adhesion according to claim 1, wherein the fatty acid ester compound (D) is a pentaerythritol-based compound.

4. The polybutylene terephthalate resin composition for silicone adhesion according to any one of claims 1 to 3, wherein the olefin-based elastomer (B) containing a glycidyl group is a copolymer of an α-olefin, a glycidyl ester of an α,β-unsaturated acid, and an α,β-unsaturated carboxylic acid alkyl ester.

5. 5. The polybutylene terephthalate resin composition for silicone adhesion according to claim 1, which is used for adhesion to condensation reaction type silicones.

6. 5. The polybutylene terephthalate resin composition for silicone adhesion according to claim 1, which is used for adhesion to addition reaction type silicones.

7. A molded article comprising the polybutylene terephthalate resin composition according to any one of claims 1 to 6.

8. 7. A composite molded article obtained by bonding a molded article made of the polybutylene terephthalate resin composition according to any one of claims 1 to 6 and another molded article with silicone.

9. 7. A composite molded article comprising a molded article made of the polybutylene terephthalate resin composition according to any one of claims 1 to 6 and a metal part bonded with silicone.

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