JP2016084454A - Fiber reinforced resin molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber reinforced resin molded article by molding a polycarbonate resin composition excellent in not only surface hardness, but also transparency, rigidity and wrap property.SOLUTION: There is provided a fiber reinforced resin molded article by molding a polycarbonate resin composition containing 100 pts.wt. of a resin component consisting of a polycarbonate resin (A) of 35 to 58 wt.% and a surface hardness improver (B) of 42 to 65 wt.% and 5 to 20 pts.wt. of a glass fiber (C) having a flat cross section with average of a major axis of a fiber cross section of 10 to 50 um and an average of a ratio between the major axis and a minor axis (major axis/minor axis) of 2 to 8, where the surface hardness improver (B) is a copolymer consisting an aromatic (meth)acrylate unit of 5 to 80 wt.% and a methyl methacrylate unit of 20 to 95 wt.%, and having weight average molecular weight of the copolymer of 5000 to 30000.SELECTED DRAWING: None

Description

  The present invention relates to a fiber-reinforced resin molded article formed by molding a polycarbonate resin composition that is excellent not only in surface hardness but also in transparency, rigidity, and warpage.

  Polycarbonate resins are thermoplastic resins that are excellent in transparency, heat resistance, thermal stability, and the like, and are therefore used for electrical and electronic component casings and automotive interior materials.

  Polycarbonate resin is expected to be used as a cover for display parts of electrical and electronic equipment, as a substitute for plate glass used in automobiles and building materials because of its transparency. Since the hardness is low, the molded product obtained from the polycarbonate resin has a drawback of being easily damaged.

  Until now, in order to improve the rigidity of the polycarbonate resin composition, a method of adding glass fibers that reinforce the polycarbonate resin has been proposed. However, since the refractive index of the added glass fiber material (example: refractive index of E glass at a wavelength of 589 nm: 1.555) and the refractive index of the polycarbonate resin (1.580-1.590) are significantly different, polycarbonate When glass fiber is added to the resin, it is difficult to maintain the transparency of the composition due to the difference in refractive index between the two, and because the glass fiber is a fibrous filler, it is caused by a characteristic called anisotropy of the molded product. That is, there is a problem that warpage occurs in a molded product due to a difference in molding shrinkage rate between the flow direction and the direction perpendicular to the flow.

  For such problems, by improving the glass fiber component composition, the refractive index of the glass fiber is improved to the same level as that of the polycarbonate resin, and the transparency of the glass fiber reinforced polycarbonate resin molded product is maintained. It is being considered.

  For example, Patent Document 1 proposes a polycarbonate resin composition that maintains transparency by blending glass fibers in which the refractive index of glass fibers is approximately the same as that of polycarbonate resin by blending specific inorganic components. However, there is no description about improving the surface hardness.

  Further, in order to improve the scratch resistance (surface hardness) of the polycarbonate resin molded product, a method of coating the surface of the polycarbonate resin with an ultraviolet curable resin has been proposed. However, this method has a problem that due to the flexibility derived from the polycarbonate resin, the pencil hardness requirement required for display applications cannot be satisfied.

  On the other hand, in order to obtain a molded article excellent in surface hardness and transparency, a resin composition of a polycarbonate resin and an acrylic surface hardness improver has been proposed (see Patent Document 2 and Patent Document 3). However, the resin compositions described in these documents have a problem that the surface hardness is high but the hue is lowered. In addition, there is no description on improving the warpage of the molded product.

Japanese Patent No. 5013798 JP 2009-280713 A JP 2010-116501 A

  The present invention solves the above-mentioned problems, that is, a polycarbonate resin that can exhibit stable dimensionality that is excellent not only in surface hardness but also in rigidity and without causing warpage as much as possible while maintaining the transparency inherent in the polycarbonate resin. It aims at providing the fiber reinforced resin molded article which shape | molds a composition and is used in a specific use.

  As a result of intensive studies to solve the above problems, the present inventors have used not only surface hardness while maintaining transparency by using a specific surface hardness improver and glass fiber having a flat cross section. Thus, a polycarbonate resin composition excellent in rigidity and warpage was obtained, and it was found that a molded product formed by molding the polycarbonate resin composition can be suitably applied to a specific application, and the present invention has been completed.

That is, the present invention relates to 100 parts by weight of a resin component consisting of 35 to 58% by weight of a polycarbonate resin (A) and 42 to 65% by weight of a surface hardness improver (B).
It contains 5 to 20 parts by weight of glass fiber (C) having a flat cross section having an average value of the major axis of the fiber cross section of 10 to 50 μm and a ratio of the major axis to the minor axis (major axis / minor axis) of 2 to 8. The surface hardness improver (B) is a copolymer comprising 5 to 80% by weight of aromatic (meth) acrylate units and 20 to 95% by weight of methyl methacrylate units, and the copolymer A polycarbonate resin composition having a polymer weight average molecular weight of 5000 to 30000 is molded, and is any one of a housing, casing, cover, or window member for use in electrical electronics, vehicles, or construction. A fiber-reinforced resin molded product is provided.

  The fiber-reinforced resin molded product of the present invention is a product that dramatically improves not only the surface hardness but also the stable dimensionality that hardly causes warpage while maintaining the excellent transparency inherent in the polycarbonate resin. is there. Further, it is possible to suppress problems such as dropping of heavy objects onto a product made of the fiber-reinforced resin molded product of the present invention and cracking when the product itself is dropped, which is useful as a molded product for a specific application.

  Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples and the like, and is within the scope of the present invention. Any change can be made.

  The use of the fiber-reinforced resin molded article of the present invention is a member for electric / electronic equipment, vehicle or construction that requires excellent transparency, surface hardness, appearance and rigidity, such as a housing, casing, cover, interior material or A window member etc. are mentioned as a preferable example. In particular, a portable electronic device housing and the like are preferable examples. More specifically, a laptop computer, a portable information terminal such as a smart phone, a video camera, a digital camera, a housing for a smart meter, a casing, a substitute for a metal product used for an internal chassis, and the like.

  Moreover, it is useful also for application to the substitute (window member / glazing material) etc. of the plate glass for vehicles or buildings.

  The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example of the polymer is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (commonly referred to as bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone Sulfone, and the like.

  These may be used alone or in combination of two or more. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4′-dihydroxydiphenyl, and the like may be used in combination.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination. Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin (A) is not particularly limited, but is usually in the range of 10,000 to 100,000, more preferably 14,000 to 30,000, and even more preferably 16,000 to 26,000 in terms of moldability and strength. Moreover, when manufacturing this polycarbonate resin, a molecular weight modifier, a catalyst, etc. can be used as needed.

  The compounding quantity of polycarbonate resin (A) is 35 to 58 weight%. If it exceeds 58% by weight, the surface hardness is inferior, and if it is less than 35% by weight, the transparency is inferior. A preferable blending amount is 42 to 55% by weight, and more preferably 42 to 50% by weight.

  The surface hardness improver (B) used in the present invention is a copolymer composed of 5 to 80% by weight of aromatic (meth) acrylate units and 20 to 95% by weight of methyl methacrylate units. The weight average molecular weight of the coalescence is 5000-30000. In the present specification, (meth) acrylate means acrylate or methacrylate.

  Examples of the aromatic (meth) acrylate include phenyl (meth) acrylate and benzyl (meth) acrylate. These can be used alone or in combination of two or more. Of these, phenyl methacrylate and benzyl methacrylate are preferable, and phenyl methacrylate is more preferable.

  If the content of the aromatic (meth) acrylate unit in the surface hardness improver (B) is 5% by weight or more, transparency is maintained, and if it is 80% by weight or less, the phase with the polycarbonate resin (A) is maintained. Since the capacity is not too high and the migration to the surface of the molded article does not decrease, the surface hardness is not decreased, which is preferable. Moreover, if the content rate of an aromatic (meth) acrylate unit is the range of 20 to 70 weight%, it is still more preferable from expressing high surface hardness, maintaining transparency further.

  The surface hardness improver (B) may contain other monomer units other than the aromatic (meth) acrylate unit and the methyl methacrylate unit, if necessary. Examples of other monomers constituting other monomer units include methacrylates such as ethyl methacrylate, butyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, 2- Acrylates such as ethylhexyl acrylate and glycidyl acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; diene monomers such as butadiene, isoprene and dimethylbutadiene; vinyl ether ethers such as vinyl methyl ether and vinyl ethyl ether Body; carboxylic acid vinyl monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene and isobutylene; acrylic acid, methacrylic acid and male Ethylenically unsaturated carboxylic acid monomers such as acid and itaconic acid; vinyl halide monomers such as vinyl chloride and vinylidene chloride; maleimides such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide and N-methylmaleimide Monomers; Examples include cross-linking agents such as allyl (meth) acrylate, divinylbenzene, and 1,3-butylene dimethacrylate. Of these, methacrylate, acrylate, and vinyl cyanide monomer are preferable, and acrylate is more preferable from the viewpoint of suppressing thermal decomposition of the surface hardness improver (B). These monomers can be used alone or in combination of two or more.

  When other monomer units are contained, the constituent monomers of the surface hardness improver (B) are aromatic (meth) acrylate units of 5-79.9% by weight, methyl methacrylate units of 20-94.9% by weight. And other monomer units in the range of 0.1 to 10% by weight.

  As a polymerization method of the monomer for obtaining the surface hardness improver (B), a known method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method, or the like can be used. A suspension polymerization method and a bulk polymerization method are preferable, and a suspension polymerization method is more preferable. Further, additives necessary for the polymerization can be appropriately added as necessary, and examples thereof include a polymerization initiator, an emulsifier, a dispersant, and a chain transfer agent.

  The weight average molecular weight of the surface hardness improver (B) is 5,000 to 30,000. When the weight average molecular weight is in the range of 5000 to 30000, the compatibility with the polycarbonate resin (A) is good, and the effect of improving the surface hardness is excellent. In addition, Preferably it is the range of 10,000-25000.

The weight average molecular weight is measured using gel permeation chromatography (GPC), and the detailed conditions are as follows:
As a GPC column, PLGEL 5 μm MIXED-C manufactured by Agilent Technologies was used, and THF was used as a mobile phase.

  The compounding amount of the surface hardness improver (B) is 42 to 65% by weight. If it exceeds 65% by weight, the transparency is inferior, and if it is less than 42% by weight, the surface hardness is inferior. A preferable blending amount is 42 to 55% by weight, and more preferably 42 to 50% by weight.

  The glass fiber (C) having a flat cross section used in the present invention has an average value of the major axis of the fiber cross section of 10 to 50 μm and an average value of the ratio of the major axis to the minor axis (major axis / minor axis) of 2 to 8. It is a certain glass fiber (C). The glass used for the glass fiber is preferably alkali-free glass (E glass, refractive index at a wavelength of 589 nm: around 1.555). The major axis average value of the glass fiber (C) is 10 to 50 μm, preferably 15 to 40 μm, more preferably 25 to 30 μm. Further, the average value of the ratio of the major axis to the minor axis (major axis / minor axis) is 2 to 8, preferably 2 to 7, and more preferably 2.5 to 5. These are produced according to any conventionally known method.

  If the major axis of the glass fiber (C) is less than 10 μm, the production is difficult, and if it exceeds 50 μm, the appearance of the molded product surface of the polycarbonate resin composition is impaired, which is not preferable. If the ratio of the major axis to the minor axis is less than 2, the dimensional stability is inferior, and if it exceeds 8, the strength may be inferior.

  The glass fiber (C) can be surface-treated with a silane coupling agent such as aminosilane or epoxysilane for the purpose of improving the adhesion to the polycarbonate resin. Further, when glass fibers are handled, they can be focused by a bundling material such as urethane or epoxy for the purpose of improving the handleability.

  The compounding quantity of glass fiber (C) is 5 to 20 weight%. If it is 5% by weight or less, it is not preferable because it is inferior in rigidity. A preferable blending amount is 5 to 15% by weight, and more preferably 5 to 10% by weight.

  Furthermore, various resins, antioxidants, fluorescent brighteners, pigments, dyes, carbon black, fillers, mold release agents, ultraviolet absorbers are added to the polycarbonate resin composition of the present invention within the range not impairing the effects of the present invention , Antistatic agents, rubber, softeners, spreading agents (liquid paraffin, epoxidized soybean oil, etc.), flame retardants, additives such as organic metal salts, polytetrafluoroethylene resin for preventing dripping, etc. .

  Examples of the various resins include polystyrene, high impact polystyrene, ABS, AES, AAS, AS, acrylic resin, polyamide, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polysulfone, and polyphenylene sulfide resin. Two or more kinds may be used in combination.

  Examples of the antioxidant include phosphorus antioxidants and phenolic antioxidants. Of these, hindered phenolic antioxidants are preferably used. For example, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], thiodiethylene-bis [ Examples include 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate. In particular, a compound represented by the following structural formula is preferably used. Examples of the antioxidant include Irganox 1076 manufactured by BASF.

  As the method for molding the fiber-reinforced resin molded product of the present invention, extrusion molding or injection molding is used. For extrusion molding, a mold such as a sheet using an extruder or profile extrusion is used, and for injection molding, a mold capable of molding the molded product and a 100 to 200 T class injection molding machine are used. The molding processing temperature is preferably 230 to 260 ° C.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily changed or modified without departing from the spirit of the present invention. Unless otherwise specified, “%” and “parts” in the examples indicate “% by weight” and “parts by weight” based on the weight standard, respectively.

Details of the raw materials used are as follows.
Polycarbonate resin (A):
Polycarbonate resin synthesized from bisphenol A and phosgene (manufactured by Sumika Stylon Polycarbonate, Caliber 200-20, viscosity average molecular weight 19000, hereinafter abbreviated as “PC”)
Surface hardness improver (B):
Copolymer of aromatic (meth) acrylate unit and methyl methacrylate unit (Metbrene H-880 manufactured by Mitsubishi Rayon Co., Ltd., weight average molecular weight 10,000,
Hereinafter abbreviated as “component B”)
Glass fiber having flat cross section (C): Flat glass fiber (Nittobo CSG-3PA-830S major axis 28um minor axis 7um)
Hereinafter abbreviated as “glass fiber”

(Preparation of polycarbonate resin composition pellets)
The above-mentioned various blending components are collectively put in a tumbler at the blending ratio shown in Table 1, and after dry mixing for 10 minutes, using a twin-screw extruder (KTX37 manufactured by Kobe Steel) at a melting temperature of 250 ° C. It knead | mixed and the pellet of the polycarbonate resin composition was obtained.

(Evaluation of transparency of molded products)
The pellets of the various resin compositions obtained above were each dried at 120 ° C. for 4 hours, and then set to a set temperature of 250 ° C. and an injection pressure of 1600 kg / cm 2 using an injection molding machine (Japan Steel Works J-100E-C5). Thus, a test piece for transparency evaluation (50 × 90 × 3, 2, 1 mm (3 thickness) three-stage plate) was prepared. Using the obtained test piece, according to JIS K7361, the light transmittance of the test piece thickness of 2 mm was measured, and the total light transmittance was 80% or more and the haze was 40% or less.

(Evaluation of warpage of molded products)
The pellets of the various resin compositions obtained above were each dried at 120 ° C. for 4 hours, and then set to a set temperature of 250 ° C. and an injection pressure of 1600 kg / cm 2 using an injection molding machine (Japan Steel Works J-100E-C5). Thus, a test piece for dimensional evaluation (plate of 150 × 90 × 3 mm) was prepared. Measure the molding shrinkage rate in the flow direction and in the direction perpendicular to the flow of the test piece obtained, and determine the anisotropy of the molding shrinkage rate by dividing the molding shrinkage rate in the flow direction by the molding shrinkage rate in the direction perpendicular to the flow. And warped. A warp property of 0.95 or higher was considered good.

(Evaluation of flexural modulus of molded product)
The pellets of the various resin compositions obtained above were each dried at 120 ° C. for 4 hours, and then set to a set temperature of 250 ° C. and an injection pressure of 1600 kg / cm 2 using an injection molding machine (Japan Steel Works J-100E-C5). A test piece according to the ISO test method was prepared, and the bending elastic modulus (rigidity) was measured according to ISO 178 using the obtained test piece, and the bending elastic modulus was determined to be 3000 MPa or more.

(Pencil hardness)
The pellets of the various resin compositions obtained above were dried at 120 ° C. for 4 hours, respectively, and then set at a set temperature of 250 ° C. and an injection pressure of 1600 kg / cm ² using an injection molding machine (Japan Steel Works J-100E-C5). The test piece for pencil hardness evaluation (150x90x2.0mm) was created. Using the obtained test piece, the pencil hardness at which no scratches were observed on the surface of the test piece was determined with a pencil hardness measuring machine (pencil scratch coating film hardness tester manufactured by Toyo Seiki Co., Ltd.) according to JISK5600-5-4. . This pencil hardness was used as an evaluation of surface hardness, and H or higher was considered good.

判定： ○： 良好 ×：不良

Judgment: ○: Good ×: Bad

As shown in Example 1, those satisfying the constituent requirements of the present invention satisfied the required performance.
On the other hand, as shown in Comparative Examples 1 to 4, those that do not satisfy the constituent requirements of the present invention have the following drawbacks.
In Comparative Example 1, the blending amount of the component B (surface hardness improver) and the glass fiber were less than the specified amount, and the pencil hardness and the flexural modulus were poor.
In Comparative Example 2, the bending elastic modulus was poor when the blending amount of the glass fiber was less than the specified amount.
In Comparative Example 3, the blending amount of the component B (surface hardness improver) was larger than the specified amount and the glass fiber was small, and the flexural modulus was poor.
In Comparative Example 4, there were many glass fibers, and the dimensionality, total light transmittance, and haze were poor.

  The fiber-reinforced resin molded product of the present invention is a product that dramatically improves not only the surface hardness but also the stable dimensionality that hardly causes warpage while maintaining the excellent transparency inherent in the polycarbonate resin. is there. In addition, it is possible to suppress problems such as dropping of heavy objects on products made of the fiber reinforced resin molded product of the present invention and cracking when the product itself falls, and it is useful as a molded product for specific applications, and its industry The above utility value is extremely high.

Claims (2)

The average value of the major axis of the fiber cross section is 10 to 50 μm per 100 parts by weight of the resin component consisting of 35 to 58% by weight of the polycarbonate resin (A) and 42 to 65% by weight of the surface hardness improver (B). It contains 5 to 20 parts by weight of a glass fiber (C) having a flat cross section with an average value of (major axis / minor axis) of 2 to 8, and the surface hardness improver (B) is an aromatic (meth) acrylate unit 5 A polycarbonate resin composition having a weight average molecular weight of 5,000 to 30,000, which is a copolymer comprising ˜80 wt% and methyl methacrylate units 20 to 95 wt%, A fiber-reinforced resin molded article, which is any one of a housing, a casing, a cover, and a window member for use in a vehicle or a building. The fiber-reinforced resin molded article according to claim 1, wherein the resin component comprises 45 to 58% by weight of a polycarbonate resin (A) and 42 to 55% by weight of a surface hardness improver (B).