JP3288911B2 - Polycarbonate resin composition and molded article thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polycarbonate resin composition and a molded product obtained by molding the same. More specifically, the present invention relates to a polycarbonate resin composition having excellent moldability, rigidity, and impact strength, and a molded article having excellent surface appearance obtained by molding the same.

[0002]

2. Description of the Related Art Polycarbonate resins are widely used industrially because of their excellent mechanical and thermal properties. However, polycarbonate resin is inferior in moldability and processability, so a number of polymer alloys with other thermoplastic resins have been developed. Among them, polymer alloys with ABS resin are widely used in the automotive field, OA equipment field, electronic / electric field, etc. It's being used. In particular, in recent years, in OA equipment, home electric appliances, and the like, the tendency of lightness, thinness, and small size has become increasingly strong, and accordingly, materials having high rigidity have been required. In order to improve the rigidity of a thermoplastic resin, a method of blending a fibrous filler such as glass fiber (Japanese Patent Publication No. 55-117)
No. 02), a method of blending scaly or plate-like inorganic fillers such as talc and mica (JP-B-7-33473).
Has been proposed. However, the former resin composition in which a fibrous filler such as glass fiber or carbon fiber is blended has the problems that the rigidity is improved but the impact strength is reduced, and the appearance of the obtained molded product is also deteriorated. In particular, when a thin product is injection-molded, there is a disadvantage that a problem occurs in the dimensional accuracy (particularly, warpage) of the molded product. The latter resin composition containing a flaky or plate-like inorganic filler such as talc or mica has a surface appearance of a molded article in comparison with a resin composition containing a fibrous filler such as glass fiber or carbon fiber. Although good, the reinforcing effect is smaller than that of the fibrous inorganic filler, so that the mechanical strength such as rigidity cannot be sufficiently improved. Japanese Patent Application Laid-Open No. 149948/1995 proposes a resin composition containing specific short-fibrous calcium silicate. However, since this filler is a short fiber type, the surface appearance of the molded article is good and the impact strength is small as well as the resin composition containing talc and mica, but the reinforcing effect is small, Insufficient mechanical strength such as rigidity. Therefore, there is a demand for a polycarbonate resin which is excellent in molding workability, is excellent in rigidity and impact strength, and gives a molded product excellent in surface appearance.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polycarbonate resin which is excellent in molding workability, is excellent in rigidity and impact strength, and gives a molded article excellent in surface appearance.

The present inventors have conducted intensive studies to achieve the above object. As a result, a specific inorganic filler and a specific inorganic filler have been added to a polycarbonate resin composition containing a thermoplastic graft copolymer and having improved moldability. By blending a specific olefin-based wax, it was found that the rigidity and impact strength were excellent, and the molded product obtained therefrom was excellent in surface appearance, and the present invention was reached.

[0005]

The present invention relates to a thermoplastic graft copolymer comprising (A) 90 to 10% by weight of a polycarbonate resin and (B) a thermoplastic diene rubber component, which is obtained by grafting a vinyl cyanide compound and an aromatic vinyl compound. Polymer 10
100% by weight of a resin composition comprising 90% by weight of (C) a fibrous inorganic filler containing calcium silicate as a main component.
0 parts by weight and (D) an olefin-based wax containing a carboxyl group and / or a carboxylic anhydride group
Polycarbonate resin composition 1 containing 5 parts by weight
00 parts by weight of, Ri name by incorporating a rubber polymer from 1 to 20 parts by weight, the rubbery polymer is one or more pigs
Diene-alkyl (meth) acrylate-styrene copolymer
Combined, butadiene-alkyl acrylate-alkyl
(Meth) acrylate copolymer or polyorganos
Loxane rubber and polyalkyl (meth) acrylate rubber
Composite elastic weight having a structure in which components are intertwined with each other
Those of the molded article obtained by molding the polymer der Ru polycarbonate resin composition and the resin composition.

The polycarbonate resin used as the component (A) in the present invention is an aromatic polycarbonate resin obtained by reacting a dihydric phenol with a carbonate precursor. As the dihydric phenol used here, for example, 2,2
-Bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl)
Ethane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2- (4-hydroxy-
3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfone and the like. Preferred dihydric phenols are bis (4-hydroxyphenyl) alkanes, with bisphenol A being particularly preferred. Examples of the carbonate precursor include carbonyl halide, carbonyl ester, and haloformate, and specific examples include phosgene, diphenyl carbonate, and dihaloformate of dihydric phenol. In producing the polycarbonate resin, the above dihydric phenol may be used alone or in combination of two or more, and the polycarbonate resin is a branched polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound. Or a mixture of two or more polycarbonate resins.

The molecular weight of the polycarbonate resin does not need to be particularly limited, but if it is too low, the strength is not sufficient.
If it is too high, the melt viscosity becomes high and molding becomes difficult. Therefore, it is usually expressed as a viscosity average molecular weight of 10,000 to 50,
000, preferably 15,000 to 30,000. The viscosity average molecular weight (M) here is methylene chloride 1
The specific viscosity (η _sp ) obtained from a solution in which 0.7 g of a polycarbonate resin was dissolved in 00 ml at 20 ° C. was inserted into the following equation. η _sp /C=[η]+0.45×[η] ² C [η] = 1.23 × 10 ^-4 M ^0.83 (where [η] is the intrinsic viscosity and C is the polymer concentration of 0.7)

The basic means for producing a polycarbonate resin will be briefly described. In the solution method using phosgene as a carbonate precursor, the reaction is usually performed in the presence of an acid binder and an organic solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the organic solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. Further, a catalyst such as a tertiary amine or a quaternary ammonium salt can be used to promote the reaction, and a terminal stopper such as an alkyl-substituted phenol such as phenol or p-tert-butylphenol can be used as a molecular weight regulator. It is desirable to use. The reaction temperature is usually 0 to 40 ° C., the reaction time is preferably several minutes to 5 hours, and the pH during the reaction is preferably maintained at 10 or more.

In a transesterification reaction using a carbonic acid diester as a carbonate precursor (melting method), a predetermined ratio of a dihydric phenol is stirred with a carbonic acid diester while being heated in the presence of an inert gas to produce alcohol or phenols. It is performed by the method of distilling. The reaction temperature varies depending on the boiling point of the alcohol or phenol to be formed, but is usually in the range of 120 to 300 ° C. The reaction is completed while distilling off alcohol or phenols produced by reducing the pressure from the beginning. Further, a catalyst usually used in a transesterification reaction for promoting the reaction can be used. Examples of the carbonic acid diester used in this transesterification reaction include diphenyl carbonate, dinaphthyl carbonate, dimethyl carbonate,
Examples thereof include diethyl carbonate and dibutyl carbonate. Of these, diphenyl carbonate is particularly preferred.

As the thermoplastic graft copolymer used as the component (B), a resin usually called an ABS resin can be used. As the diene rubber component forming the thermoplastic graft copolymer, for example, a rubber having a glass transition point of 10 ° C. or less such as polybutadiene, polyisoprene, and styrene-butadiene copolymer is used, and the ratio is (B). It is preferably from 5 to 80% by weight of the components. Examples of the vinyl cyanide compound grafted to the diene rubber component include acrylonitrile and methacrylonitrile. The content of the vinyl cyanide compound in the component (B) is 50 to 5% by weight. preferable. Examples of the aromatic vinyl compound grafted to the diene rubber component include styrene, α-methylstyrene and nucleus-substituted styrene. The content of the aromatic vinyl compound is 50 to 95 in the component (B).
% By weight is preferred. Furthermore, methyl (meth) acrylate,
Ethyl acrylate, maleic anhydride, N-substituted maleimide and the like can be mixed and used. The thermoplastic graft copolymer (B) component may be produced by any of bulk polymerization, suspension polymerization, and emulsion polymerization, and may be copolymerized in one step or in multiple steps. It may be polymerized. The component (B) can be used alone or in combination of two or more.

The fibrous inorganic filler mainly composed of calcium silicate used as the component (C) is a natural white mineral (calcium metasilicate) having needle-like crystals, and has a chemical formula C
a SiO ₃ , usually 50% by weight of SiO ₂ , C
aO contains 47% by weight, and other components such as Fe ₂ O ₃ and Al ₂ O ₃ , and has a specific gravity of about 2.9. Such a fibrous inorganic filler containing calcium silicate as a main component is generally called wollastonite. The wollastonite used in the present invention has a particle size distribution of 3 μm or more of 7 μm.
It is preferable that 5% or more and 10 μm or more have 5% or less and the aspect ratio L / D is 8 or more. Particle size distribution 3μ
If m or more is less than 75%, the reinforcing effect tends to be insufficient, and the rigidity tends to be insufficient. 10% or more is 5%
Exceeding the impact strength is liable to lower the impact strength and deteriorates the surface appearance of the obtained molded article, which is not preferred.
If the aspect ratio is less than 8, the reinforcing effect tends to be insufficient, and the rigidity is reduced. If the aspect ratio is more than 50, the appearance of the obtained molded product is undesirably deteriorated. The wollastonite may be subjected to a surface treatment with a normal surface treatment agent, for example, a coupling agent such as a silane coupling agent or a titanate coupling agent.

The particle size distribution as used herein means that 5 g of wollastonite is added together with 5 ml of 10% sodium hexametaphosphate to 25 g.
After adding to 0 ml graduated cylinder, pure water was added up to 250 ml and the well-dispersed suspension was arbitrarily suctioned (t),
The suction was performed by using a 10 ml hole pipette at an arbitrary suction position (h), the sucked suspension was transferred to an evaporating dish, and the weight (w) obtained by evaporating and drying was inserted into the following equation [A].

[0013]

(Equation 1)

(However, the dispersant weight is 0.02 g in weight of sodium hexametaphosphate) The particle diameter (d) is determined by an arbitrary suction time (t), an arbitrary suction position (h), and a true specific gravity of wollastonite ( ρ _P ) into the following equation [B].

[0015]

(Equation 2)

This measuring method is based on the Andreazen pipette method. The aspect ratio L / D means that wollastonite is photographed at a magnification of 1,000 times with a scanning electron microscope, and the average fiber length (L) and average fiber diameter (100) of 100 wollastonite fibers in the photograph are measured. D).

The olefin wax containing a carboxyl group and / or a carboxylic anhydride group used as the component (D) has a carboxyl group and / or a carboxylic anhydride group obtained by specially treating the olefin wax. Wax. It is considered that the addition of the wax reduces the destruction of the inorganic filler due to shearing during the molding process, and exhibits an effect of maintaining the original aspect ratio. The carboxyl group or carboxylic acid anhydride group may be bonded to any part of the olefin wax, and the concentration thereof is not particularly limited, but is 0.1 to 6 in terms of carboxyl group per 1 g of the olefin wax. The range of meq / g is preferred. 0.1 meq / g
If the amount is less than this, the effect of improving rigidity and impact resistance becomes insufficient. If the amount is more than 6 meq / g, the thermal stability of the olefin wax itself deteriorates, which is not preferable. Commercially available olefin-based waxes include, for example, Diacarna-PA30 (trade name of Mitsubishi Kasei Co., Ltd.), 2203A, 110 of high wax acid treatment type.
5A (trade name of Mitsui Petrochemical Co., Ltd.), oxidized paraffin (manufactured by Nippon Seiro Co., Ltd.) and the like can be used alone or as a mixture of two or more.

Next, the mixing ratio of each component of the resin composition of the present invention will be described. Component (A) and resin (B) in the resin composition
The mixing ratio of the components is expressed based on the total weight of the two.
The component (A) is 90 to 10 per 100% by weight in total.
% By weight, preferably in the range of 80 to 20% by weight,
The component (B) is 10 to 90% by weight, preferably 20 to 80% by weight.
% By weight. When the compounding ratio of the component (A) is less than 10% by weight, heat resistance (particularly, deflection temperature under load) and mechanical strength are reduced. On the other hand, if the content exceeds 90% by weight, the fluidity decreases, and the moldability decreases.

The component (C) is mixed in an amount of 1 to 100 parts by weight per 100 parts by weight of the total of the components (A) and (B).
Preferably it is in the range of 5 to 70 parts by weight. If the compounding ratio of the component (C) is less than 1 part by weight, the reinforcing effect is small and the rigidity is insufficient, and if it exceeds 100 parts by weight, the surface appearance of the obtained molded article is deteriorated. The mixing ratio of the component (D) is 0.02 to 5 parts by weight, preferably 0.05 to 5 parts by weight, per 100 parts by weight of the total of the components (A) and (B).
The range is 3 parts by weight. When the compounding ratio of the component (D) is less than 0.02 parts by weight, the fibrous filler in the composition is easily broken at the time of molding and the rigidity tends to be insufficient. On the other hand, if it exceeds 5 parts by weight, the appearance and the mechanical strength are lowered, which is not suitable.

The composition of the present invention contains a rubbery polymer in order to further improve the impact strength. Alkyl (meth) acrylate Li Rate - - butadiene Examples of the rubber polymer diene elastomeric polymer such as a styrene copolymer, a butadiene -
An acrylic elastic polymer such as an alkyl acrylate-alkyl (meth) acrylate copolymer, a composite elastic polymer having a structure in which a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber component are entangled with each other, and the like. These may be used alone or in combination of two or more. The compounding amount of the rubbery polymer is (A) 90 to 10% by weight of a polycarbonate resin and (B) a thermoplastic graft copolymer obtained by grafting a vinyl cyanide compound and an aromatic vinyl compound to a thermoplastic diene rubber component.
100% by weight of a resin composition comprising 90% by weight of (C) a fibrous inorganic filler containing calcium silicate as a main component.
0 parts by weight and (D) an olefin-based wax containing a carboxyl group and / or a carboxylic anhydride group
Polycarbonate resin composition 1 containing 5 parts by weight
It is in the range of 1 to 20 parts by weight with respect to 00 parts by weight. If the amount is less than 1 part by weight, the effect of improving the impact is insufficient, and if it exceeds 20 parts by weight, heat resistance and rigidity are reduced.

The resin composition of the present invention is produced by mixing the above-mentioned components simultaneously or in an arbitrary order by a mixer such as a tumbler, a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, an extruder and the like. be able to.
Furthermore, flame retardants (for example, aromatic halogen compounds, halogenated epoxy resins, halogenated polycarbonate resins, etc. as halogen-based flame retardants, and triphenyl phosphate, tricresyl phosphate as phosphorus-based flame retardants, as long as the object of the present invention is not impaired) Cresyl diphenyl phosphate, etc.), an antioxidant (for example, a hindered phenol compound), an ultraviolet absorber, a release agent, an antistatic agent, a foaming agent, a dye and a pigment may be included. The resin composition thus obtained can be easily molded by methods such as extrusion molding, injection molding, and compression molding, and can also be applied to blow molding, vacuum molding, and the like.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described below with reference to examples. The parts in the examples are parts by weight, and the evaluation was made by the following method. (1) Rigidity: Flexural modulus was measured according to ASTM D-790. (2) Impact resistance: Impact was measured according to ASTM D-256 (1/8 ″ with Izod notch). (3) Appearance: A square plate of 50 mm × 80 mm × 2 mm was visually determined, and inorganic filler was determined. A mark that appeared to be raised or spots formed on the surface was indicated by "x", and an inorganic filler having no lift and no spots on the surface was indicated by "o".

[Examples 1 and 2 , Comparative Examples 1 to 7 ] After mixing the components shown in Table 1 with a V-type blender shown in the table, a vented twin-screw extruder having a diameter of 30 mm [Nippon Steel Corporation] TEX30XSST] to obtain a cylinder temperature of 24
Pelleted at 0 ° C. After drying these pellets at 110 ° C. for 5 hours, an injection molding machine [T-1 manufactured by FANUC Corporation] was used.
[50D], various test pieces were prepared at a cylinder temperature of 250 ° C. and a mold temperature of 70 ° C., and evaluated. Table 1 shows the evaluation results. In addition, the symbol which shows each component of Table 1 is as follows. PC: a polycarbonate resin having a viscosity average molecular weight of 22,500 obtained from bisphenol A and phosgene by a conventional method [L-1225 manufactured by Teijin Chemicals Ltd.] ABS: ABS resin [Santac UT-61 manufactured by Mitsui Toatsu Chemicals, Inc.] WSN: Wollastonite (fibrous) [WIC10 manufactured by Kinsei Mate Co., Ltd., 82.6 with a particle size distribution of 3 μm or more]
%, 10% or more is 1.3% and the average diameter D is 4.5 μm,
Aspect ratio L / D = 8] CS: Chopped glass fiber [Nittobo Co., Ltd. 3PE-
941, average diameter D = 13 μm, aspect ratio L / D = 2
30] Talc: scaly talc [Talc P- manufactured by Nippon Talc Co., Ltd.
3, average particle diameter of about 2.8 μm] Wax: olefin wax obtained by copolymerization of α-olefin and maleic anhydride [Diacarna-PA30 manufactured by Mitsubishi Kasei Corporation, maleic anhydride content 10% by weight] MBS: MBS resin (elastic polymer) [PARALOID EXL-2602 manufactured by Kureha Chemical Industry Co., Ltd.] MB: composite rubber-based graft copolymer [METABLEN S-2001 manufactured by Mitsubishi Rayon Co., Ltd.]

[0024]

[Table 1]

[0025]

The resin composition of the present invention is excellent in mechanical strength such as rigidity and impact strength, and has good surface appearance of a molded product, and is suitable for various industrial uses such as automobile field, OA equipment field, and electronic / electric field. Extremely useful.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 55/02 C08K 3/34 C08L 69/00 C08L 91/06

Claims (4)

(57) [Claims] (A) a polycarbonate resin 90 to 10
(C) calcium silicate is added to 100 parts by weight of a resin composition composed of 10 to 90% by weight of a thermoplastic graft copolymer obtained by grafting a vinyl cyanide compound and an aromatic vinyl compound to a thermoplastic diene rubber component (B). Resin composition comprising 1 to 100 parts by weight of a fibrous inorganic filler having as a main component and 0.02 to 5 parts by weight of (D) an olefin wax containing a carboxyl group and / or a carboxylic anhydride group things to 100 parts by weight, Ri name by incorporating a rubber polymer from 1 to 20 parts by weight, the rubbery polymer
Is one or more butadiene-alkyl (meth)
Acrylate-styrene copolymer, butadiene-alkyl
Ruacrylate-alkyl (meth) acrylate copolymer
Body or polyorganosiloxane rubber and polyalkyl
(Meth) acrylate rubber component
Composite elastic polymer der Ru polycarbonate resin composition having a granulation. 2. The particle size distribution of the fibrous inorganic filler containing calcium silicate as a main component is 75% or more when the particle size distribution is 3 μm or more.
2. The polycarbonate resin composition according to claim 1, wherein μm or more is 5% or less and aspect ratio L / D is 8 or more. (A) polycarbonate resin 90 to 10
(C) based on 100 parts by weight of a resin composition consisting of 10 to 90% by weight of a thermoplastic graft copolymer obtained by grafting a vinyl cyanide compound and an aromatic vinyl compound to a thermoplastic diene rubber component and (B) a thermoplastic diene rubber component 1 to 100 parts by weight of a fibrous inorganic filler mainly composed of calcium silicate and (D)
For 100 parts by weight of a polycarbonate resin composition containing 0.02 to 5 parts by weight of an olefin wax containing a carboxyl group and / or a carboxylic anhydride group,
Ri Na by incorporating a rubber polymer from 1 to 20 parts by weight, the rubbery
The polymer is one or more butadiene-alkyl
(Meth) acrylate-styrene copolymer, butadiene
-Alkyl acrylate-alkyl (meth) acrylate
Copolymer or polyorganosiloxane rubber and poly
Alkyl (meth) acrylate rubber component entangled with each other
Suits composite has a structure elastic polymer der Ru polycarbonate resin molded article obtained by melt molding the product. 4. The particle size distribution of the fibrous inorganic filler containing calcium silicate as a main component is 75% or more when the particle size distribution is 3 μm or more.
A molded product obtained by melt-molding the polycarbonate resin composition according to claim 3, wherein the thickness is at least 5 μm and at most 5% and the aspect ratio L / D is at least 8.