JP6317713B2 - Thermoplastic resin composition - Google Patents

Description

  The present invention relates to a thermoplastic resin composition.

  Conventionally, in order to improve the mechanical properties of thermoplastic resins, it is well known to mix glass fibers with thermoplastic resins. As an alternative to metals and ceramics, housings of electronic devices, electrical and electronic parts, Used for automobile parts.

  Furthermore, in Japanese Patent Application Laid-Open No. 62-081438 (Patent Document 1), the glass fiber having an average fiber length of 2 to 10 mm is contained in the styrenic resin, so that the strength and the grease resistance at the thin protrusion are excellent. It is disclosed. JP 2011-183638 A (Patent Document 2) discloses that a thermoplastic resin contains short glass fibers having an average fiber length of 300 to 1000 μm and a fiber diameter of 3 to 6 μm, so that an appearance at a thin portion is obtained. It is disclosed that defects can be improved.

Japanese Patent Laid-Open No. 62-081438

JP 2011-183638 A

  However, in the invention described in Patent Document 1, there are problems in the surface appearance of the thin molded product and the anisotropy of the molding shrinkage rate. In addition, the invention described in Patent Document 2 has insufficient improvement in rigidity. There is still a problem with the anisotropy of molding shrinkage.

  An object of the present invention is to provide a thermoplastic resin composition having excellent rigidity and improved surface appearance of a thin molded article and anisotropy of molding shrinkage.

  The present invention provides a thermoplastic resin composition containing 10 to 100 parts by weight of glass wool having a cross-sectional diameter of 1 to 7 μm and an average fiber length of 5 to 100 mm with respect to 100 parts by weight of a thermoplastic resin. .

  According to the present invention, it is possible to provide a thermoplastic resin composition having excellent rigidity and improved surface appearance of a thin molded article and anisotropy of molding shrinkage.

  The thermoplastic resin composition according to the embodiment of the present invention contains 10 to 100 parts by weight of glass wool having a cross-sectional diameter of 1 to 7 μm and an average fiber length of 5 to 100 mm with respect to 100 parts by weight of the thermoplastic resin. It is a thermoplastic resin composition.

  The thermoplastic resin of the present invention is not particularly limited as long as it can disperse glass wool. For example, styrene resins such as rubber-reinforced styrene resins and non-rubber reinforced styrene resins; acrylic resins such as polymethyl methacrylate resins Resin; Polycarbonate resin; Polyester resin such as polybutylene terephthalate resin and polyethylene terephthalate resin; Polyamide resin; Biodegradable resin such as polylactic acid resin; (Modified) Polyphenylene ether resin, Polyoxymethylene resin, Polysulfone Engineering plastics such as polyresin, polyarylate resin, polyphenylene resin, thermoplastic polyurethane resin and the like can be used, but one or more can be used, but it is preferable to contain a styrene resin, especially rubber Reinforced styrene resin And more preferably contains.

  Specific examples of rubber reinforced styrene resins include rubber reinforced polystyrene resin (HIPS resin), acrylonitrile / butadiene rubber / styrene polymer (ABS resin), acrylonitrile / acrylic rubber / styrene polymer (AAS resin), methacrylic acid. Examples include methyl-butadiene rubber / styrene resin (MBS resin), acrylonitrile / ethylene-propylene rubber / styrene polymer (AES resin), and the like.

  The rubber-reinforced styrene resin is obtained by polymerizing an aromatic vinyl monomer and other vinyl monomers copolymerizable therewith in the presence of a rubber-like polymer (hereinafter referred to as “graft polymerization”). Is obtained.

  The rubbery polymer used for the rubber-reinforced styrene resin is not particularly limited, but polyene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) or other diene rubber, ethylene-propylene rubber, One or more selected from ethylene-propylene rubbers such as ethylene-propylene-nonconjugated diene (ethylidene norbornene, dicyclopentadiene, etc.) rubbers, acrylic rubbers such as polybutyl acrylate, silicone rubbers, and these rubbers A composite rubber etc. are mentioned, 1 type, or 2 or more types can be used.

  The rubbery polymer is preferably contained in an amount of 5 to 40% by weight in 100% by weight of the thermoplastic resin. If it is less than 5% by weight, impact resistance tends to be inferior, and if it exceeds 40% by weight, rigidity and heat resistance tend to be inferior. More preferably, it is 7-20 weight%, More preferably, it is 10-15 weight%.

  Examples of the aromatic vinyl monomer used in the rubber-reinforced styrene resin include styrene, α-methyl styrene, paramethyl styrene, bromostyrene, and the like, and one or more of them can be used. In particular, styrene and α-methylstyrene are preferable.

  Examples of other copolymerizable vinyl monomers used in rubber-reinforced styrene resins include vinyl cyanide monomers, (meth) acrylic acid ester monomers, maleimide monomers, and amide monomers. Examples of the polymer include one or two or more. Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, ethacrylonitrile, and fumaronitrile. Examples of (meth) acrylate monomers include methyl (meth) acrylate and ethyl (meth) acrylate. , (Meth) acrylic acid propyl, (meth) acrylic acid butyl, 2-ethylhexyl acrylate, (meth) acrylic acid phenyl, (meth) acrylic acid 4-t-butylphenyl, (meth) acrylic acid (di) bromophenyl , (Meth) acrylic acid chlorophenyl and the like, examples of the maleimide monomer include N-phenylmaleimide and N-cyclohexylmaleimide, and examples of the amide monomer include acrylamide and methacrylamide.

  Specific examples of the non-rubber reinforced styrene resin include styrene polymer (PS resin), styrene / acrylonitrile copolymer (AS resin), α-methylstyrene / acrylonitrile copolymer (αMS-ACN resin), methyl methacrylate.・ Styrene copolymer (MS resin), methyl methacrylate / acrylonitrile / styrene copolymer (MAS resin), styrene / N-phenylmaleimide copolymer (S-NPMI resin), styrene / N-phenylmaleimide / acrylonitrile A polymer (SA-NPMI resin) etc. are illustrated.

  The non-rubber reinforced styrene resin can be obtained by copolymerizing an aromatic vinyl monomer and another vinyl monomer copolymerizable therewith using a known polymerization method. In addition, ungrafted (co) polymers that are not grafted to the rubbery polymer contained in the resin composition obtained by graft polymerization are classified as non-rubber reinforced styrene resins.

  Examples of the aromatic vinyl monomer used for the non-rubber reinforced styrene resin and other vinyl monomers copolymerizable therewith include those similar to the rubber reinforced styrene resin.

  The thermoplastic resin of the present invention preferably contains 10% by weight or more of a non-rubber reinforced styrene resin having a weight average molecular weight of 100,000 or less with respect to 100% by weight of the thermoplastic resin. When the content is less than 10% by weight, the surface appearance of the thin molded product and the anisotropy of the molding shrinkage tend to be inferior. More preferably, it is 15-80 weight%, and when it exceeds 80 weight%, it exists in the tendency for impact resistance to be inferior. More preferably, it is 20 to 70% by weight. On the other hand, if the weight average molecular weight exceeds 100,000, the surface appearance of the thin molded product and the anisotropy of the molding shrinkage tend to be inferior. More preferably, it is 50,000-90,000, and it exists in the tendency for impact resistance to be inferior that it is less than 50,000. More preferably, it is 60,000-80,000.

  The weight average molecular weight of the non-rubber reinforced styrene resin can be appropriately adjusted by changing, for example, the type and amount of the polymerization initiator, the polymerization temperature, the type and amount of the chain transfer agent, and the like.

  The weight average molecular weight of the non-rubber reinforced styrene resin can also be stopped by dissolving in tetrahydrofuran (THF) and measuring the polystyrene equivalent weight average molecular weight of the tetrahydrofuran-soluble part using gel permeation chromatography (GPC).

  The glass wool of the present invention means a glass fiber in a cotton shape, and is completely different from a chopped strand obtained by cutting a glass fiber in which single fibers are collected into a predetermined length. When chopped strands are used, the anisotropy of the surface appearance and molding shrinkage of the thin molded product is inferior.

  The glass wool of the present invention has a cross-sectional diameter of 1 to 7 μm and an average fiber length of 5 to 100 mm. If the cross-sectional diameter is less than 1 μm, the rigidity is inferior, and if it exceeds 7 μm, the surface appearance of the thin molded product is inferior. Preferably it is 2-7 micrometers, More preferably, it is 3-6 micrometers. Further, if the average fiber length is less than 5 mm, the rigidity is inferior, and if it exceeds 100 mm, the dispersibility to the resin is inferior during melt-kneading. Preferably it is 7-80 mm, More preferably, it is 10-60 mm, More preferably, it is 20-40 mm.

  The thermoplastic resin composition of the present invention contains 10 to 100 parts by weight of glass wool with respect to 100 parts by weight of the thermoplastic resin. If the glass wool is less than 10 parts by weight, the rigidity is inferior, and if it exceeds 100 parts by weight, the surface appearance of the thin molded product is inferior. Preferably it is 15-80 weight part, More preferably, it is 20-60 weight part, More preferably, it is 25-55 weight%. In addition, content of the glass wool with respect to 100 weight part of thermoplastic resins can also be measured by ashing a thermoplastic resin composition.

  The mixing order and state of the thermoplastic resin and glass wool in the thermoplastic resin composition of the present invention are not limited at all, and there is a method of batch mixing according to the form of powder, pellets, etc., and mixing the rest after premixing a certain amount. As exemplified, it is preferable from the viewpoint of dispersibility in the resin during melt kneading that the glass wool is surface-treated with a silane coupling agent and then mixed with the thermoplastic resin.

  The silane coupling agent is not particularly limited as long as it is conventionally used, and may be determined in consideration of reactivity with a thermoplastic resin, thermal stability, and the like. For example, aminosilane-based, epoxysilane-based And silane coupling agents such as allylsilane and vinylsilane. As these silane coupling agents, commercially available products such as Z series manufactured by Toray Dow Corning, KBM series manufactured by Shin-Etsu Chemical Co., Ltd., KBE series, and JNC manufactured may be used.

  The silane coupling agent can be surface treated on glass wool by dissolving in a solvent and spraying and drying on glass wool. The silane coupling agent is preferably 0.1 to 2 parts by weight, more preferably 0.15 to 0.4 parts by weight, and still more preferably 0.2 to 0.3 parts by weight with respect to 100 parts by weight of the glass wool. It is.

  The glass wool of the present invention may be surface treated with a lubricant. The lubricant is not particularly limited as long as the glass wool is kneaded into the thermoplastic resin so that the glass wool can be easily slipped and easily dispersed in the thermoplastic resin, and has been conventionally used, such as silicon oil. A lubricant can be used.

  The glass wool of the present invention may be treated with the above silane coupling agent or lubricant, or may be treated with a silane coupling agent and a lubricant.

  In addition to the surface treatment with the above silane coupling agent and / or lubricant, the glass wool of the present invention is a known film such as epoxy resin, vinyl acetate resin, vinyl acetate copolymer resin, urethane resin, acrylic resin, etc. You may surface-treat with a forming agent. These film forming agents can be used alone or in admixture of two or more kinds, and the weight percentage of the film forming agent is preferably 5 to 15 times that of the silane coupling agent.

  The glass wool of the present invention may be subjected to the above surface treatment before kneading with a thermoplastic resin, or a glass wool surface-treated with only a lubricant is prepared, depending on the thermoplastic resin used. You may surface-treat with a desired silane coupling agent before kneading | mixing. Further, it may be surface-treated with a lubricant and a silane coupling agent in advance, or may be further pretreated with a film forming agent as required.

  In the thermoplastic resin composition of the present invention, known ultraviolet absorbers, stabilizers, antioxidants, plasticizers, colorants, color adjusters, flame retardants, antistatic agents are included within the range not impairing the object of the present invention. Additives such as fluorescent brighteners, matting agents, impact strength improvers, etc. can also be added, but from the viewpoint of interfacial adhesion between the thermoplastic resin and glass wool, a carboxylic acid group-containing copolymer and / or Alternatively, the glycidyl group-containing copolymer is preferably contained in an amount of 0.1 to 10% by weight based on 100 parts by weight of the thermoplastic resin. Examples of such additives include Bond First manufactured by Sumitomo Chemical Co., Ltd. Is available as

  The thermoplastic resin composition of the present invention comprises a thermoplastic resin, glass wool, and various additives that are added as needed, using a single-screw or multi-screw extruder, a kneader, a mix of gall, Although it can manufacture by melt-kneading at 200-400 degreeC using well-known melt-kneaders, such as a mixer, it is preferable to add after heating glass wool previously. Furthermore, it is preferable to heat-dry glass wool beforehand. In addition, after melt-kneading the thermoplastic resin and glass wool, when various additives are melt-kneaded again with the thermoplastic resin, the glass wool in the thermoplastic resin is crushed, so the various additives are thermoplastic resin and glass wool. It is preferable to knead at the same time. The production apparatus is not particularly limited, but melt kneading using a twin screw extruder is simple and preferable. The kneaded thermoplastic resin composition may be directly shaped by a mold or may be pelletized.

  The heating temperature of the glass wool is preferably about −150 ° C. to 50 ° C. based on the temperature of the molten thermoplastic resin. Increasing the melting temperature of the thermoplastic resin lowers the viscosity and facilitates dispersion of the glass wool. However, if the temperature of the thermoplastic resin is excessively high, the characteristics may change rapidly. Therefore, in the present invention, the melting temperature of the thermoplastic resin is characterized by heating the glass wool while melting at a temperature usually performed in this field. Glass wool is more preferably heated to about 20 ° C. on the basis of the melting temperature of the thermoplastic resin in order to avoid deterioration of the thermoplastic resin, although it depends on the type of thermoplastic resin used. On the other hand, the lower limit is not particularly limited since an effect can be obtained by heating, but is preferably about −100 ° C., more preferably about −50 ° C. based on the melting temperature of the thermoplastic resin. Most preferably, the glass wool is heated to the same temperature as the molten resin.

  The heating of the glass wool is not particularly limited as long as the glass wool can be heated and charged into the molten thermoplastic resin, for example, a heating device is provided in a hopper portion of the kneading apparatus where the glass wool is charged.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

Production of thermoplastic resin (a-1) In a pressure-resistant container, 93 parts of 1,3-butadiene, 7 parts of styrene, 0.5 parts of n-dodecyl mercaptan, 0.24 parts of potassium persulfate, 1.5 parts of sodium rosinate Then, 0.1 part of sodium hydroxide and 150 parts of deionized water were charged, reacted at 70 ° C. for 15 hours, and then cooled to terminate the reaction, thereby obtaining a rubbery polymer latex. 270 parts of the rubbery polymer latex obtained in the stirring tank and 0.014 part of 10% sodium dodecylbenzenesulfonate aqueous solution were added and stirred for 10 minutes, then 0.8 part of 5% aqueous phosphoric acid solution was added over 10 minutes. Added. Thereafter, 1 part of a 10% aqueous potassium hydroxide solution was added to obtain a rubbery polymer latex. 60 parts (solid content) of a rubbery polymer obtained in a nitrogen-substituted reactor, 140 parts of water, 0.1 part of ethylenediaminetetraacetic acid disodium salt, 0.001 part of ferrous sulfate, sodium formaldehyde sulfoxylate 0 .3 parts and after heating to 60 ° C., a mixture of 30 parts of styrene, 10 parts of acrylonitrile, 0.27 part of t-dodecyl mercaptan and 0.2 part of cumene hydroperoxide, 1.5 parts of potassium oleate and water A mixture of 15 parts was added continuously over 4 hours. After completion of the addition, polymerization was further performed at 60 ° C. for 2 hours. Then, the thermoplastic resin (a-1) was obtained by salting out, dehydrating and drying.

Production of thermoplastic resin (a-2) In a polymerization reactor equipped with a stirring blade, 300 parts of pure water and 0.3 part of hydroxyethyl cellulose as a suspension stabilizer were dissolved, and then cut into 3 mm square ethylene-propylene- 50 parts of ethylidene norbornene copolymer rubber (ethylene content 55%, Mooney viscosity (ML1 + 4 121 ° C.) 60) was charged and suspended. Thereafter, 37 parts of styrene, 13 parts of acrylonitrile, 3.0 parts of t-butylperoxypivalate as a polymerization initiator and 0.1 part of t-dodecyl mercaptan as a molecular weight regulator were added, and polymerization was performed at 100 ° C. for 1 hour. . Then, the thermoplastic resin (a-2) was obtained by dehydrating and drying.

Production of Thermoplastic Resin (a-3) A monomer mixture consisting of 66 parts by weight of styrene, 22 parts by weight of acrylonitrile, 12 parts by weight of ethylbenzene, and 0.54 parts by weight of t-dodecyl mercaptan was continuously added to the reactor substituted with nitrogen. The polymerization was carried out at 140 ° C. The polymerization liquid was led from the reactor to a separation and recovery step comprising a preheater and a vacuum tank, and after collection and extrusion, a thermoplastic resin (a-3) was obtained.

  After drying the obtained thermoplastic resin, 1.0 g was immersed in 20 ml of tetrahydrofuran for 24 hours, then the insoluble part was removed with a 300-mesh wire mesh, and further filtered through a disposable filter having a pore diameter of 0.45 μm was obtained by GPC (gel The polystyrene-reduced weight average molecular weight of the tetrahydrofuran-soluble part was determined by measurement by permeation chromatography), and the weight average molecular weight of the thermoplastic resin (a-3) was 120,000.

Production of Thermoplastic Resin (a-4) A monomer mixture consisting of 66 parts by weight of styrene, 22 parts by weight of acrylonitrile, 12 parts by weight of ethylbenzene, and 0.22 parts by weight of t-dodecyl mercaptan was continuously added to a nitrogen-substituted reactor. The polymerization was carried out at 140 ° C. The polymerization solution was led from the reactor to a separation and recovery step comprising a preheater and a vacuum tank, and after collection and extrusion, a thermoplastic resin (a-4) was obtained. When the weight average molecular weight in terms of polystyrene of the tetrahydrofuran soluble part was determined from the above method, the weight average molecular weight of the obtained thermoplastic resin (a-4) was 80000.

Glass wool (B-1)
Mag Izobale Co., Ltd. Glass Wool Cross Section Diameter: 4μm
Average fiber length: 9mm

Glass fiber (B-2)
SS05DE-413SP manufactured by Nittobo Co., Ltd.
Cross-sectional diameter: 6 μm
Average fiber length: 0.1 mm

Glass fiber (B-3 )
CSF 3PE-332S manufactured by Nittobo Co., Ltd.
Cross-sectional diameter: 13 μm
Average fiber length: 3mm

Examples 1-5, Comparative Examples 1-4
(A-1) to (a-4) were melt kneaded in a weight ratio shown in Table 1 at a cylinder temperature of 230 ° C. and a φ50 mm single screw extruder under conditions of a main screw rotation speed of 220 pm and a discharge rate of 40 kg / hr. (A-1) to (A-5) were obtained by pelletization. (A-1) to (A-5) were put into a hopper of a φ36 mm same-direction twin screw extruder set at 200 ° C., and (B-1) to (B-3) were previously heated and dried at 100 ° C. A side feeder set at a temperature of 200 ° C. was supplied to the resin melting part in the extruder at a weight ratio shown in Table 2, and melt kneaded and pelletized under the conditions of a main screw speed of 300 rpm and a discharge rate of 25 kg / hr. Table 2 shows the results of measuring physical properties of various molded products from the obtained pellets. In addition, each measuring method is shown below.

Evaluation of Rigidity Using the pellets obtained in each Example and Comparative Example, a test piece was molded according to ISO test method 294, and the flexural rigidity at 23 ° C. and 50% RH was measured according to ISO178. Unit: MPa

Evaluation of Molding Appearance Using the pellets obtained in each Example and Comparative Example, molding was performed with an injection molding machine (Yamagi Seiki Seisakusho SAV-30-30-P, cylinder temperature: 250 ° C., mold temperature: 60 ° C.). The surface smoothness of the plate-like molded product (thickness 2.5 mm) was visually evaluated.
◎: Extremely smooth, ○: Smooth, Δ: Only the gate part is not smooth, ×: Not smooth

Evaluation of Molding Shrinkage Ratio Using pellets obtained in each Example and Comparative Example, an injection molding machine (HP-100 manufactured by Hayabusa Iron Works, cylinder temperature: 240 ° C. (Example 3, Comparative Example 2 is 250 ° C.) A plate-shaped molded product (die: long side 150 mm, short side 90 mm, thickness 2 mm, gate position is one in the center of the short side, gate width 10 mm) is molded under the following conditions (die temperature: 60 ° C) Then, the dimensional change after being allowed to stand at 23 ° C. and 50% RH for 24 hours was measured, and the molding shrinkage ratio was evaluated from the following formula. The long side dimension was measured at a position 10 mm from the center of the short side, and the short side dimension was measured at a position 20 mm from the gate. The anisotropy of the molding shrinkage ratio is better when the molding shrinkage ratio is closer to 1.0.
Mold Shrinkage Ratio: {(Long side dimension of mold−Long side dimension of molded product) ÷ Long side dimension of mold} ÷ {(Short side dimension of mold−Short side dimension of molded product) ÷ Die of mold Short side dimension}
Injection speed 50%, pressure keeping speed 30%, pressure keeping pressure 30 kg / cm ² , cooling time 20 seconds

  The thermoplastic resin composition of the present invention is improved in rigidity, surface appearance of a thin molded product by injection molding and anisotropy of molding shrinkage ratio, so that it can be used for vehicle exterior parts, vehicle interior parts, OA equipment casings. Useful value for etc. is high.

Claims (5)

10 to 100 parts by weight of glass wool having a cross-sectional diameter of 1 to 7 μm and an average fiber length of 5 to 100 mm with respect to 100 parts by weight of the thermoplastic resin ,
In 100 parts by weight of the thermoplastic resin, 5 to 40% by weight of a rubbery polymer is contained,
Thermoplastic resin composition.   The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin contains a styrene resin.   The thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic resin contains 10% by weight or more of a non-rubber reinforced styrene resin having a weight average molecular weight of 100,000 or less.   The thermoplastic resin according to any one of claims 1 to 3, comprising 0.1 to 10% by weight of a carboxylic acid group-containing copolymer and / or a glycidyl group-containing copolymer with respect to 100 parts by weight of the thermoplastic resin. Resin composition. Per 100 parts by weight of the thermoplastic resin, the cross-section of diameter 1~7μm and an average fiber length to provide 10 to 100 parts by weight of glass wool 5 to 100 mm, seen including a step of melt-kneading,
In 100 parts by weight of the thermoplastic resin, 5 to 40% by weight of a rubbery polymer is contained,
A method for producing a thermoplastic resin composition.