JPH086013B2 - High gloss resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a resin composition having extremely excellent gloss and good impact resistance.

<Prior art> Rubber-reinforced styrene resin represented by ABS resin has excellent impact resistance, mechanical properties, molding processability and luster,
As a quasi-engineering plastic with properties intermediate between general-purpose resins and engineering resins, it is widely used in automobiles and home appliances.

On the other hand, in this home appliance application, there is an increasing demand for products having higher gloss than conventional products for the purpose of further increasing the commercial value.

Generally, to improve the surface gloss, a method of lowering the concentration of the rubbery polymer in the resin composition or a method of reducing the particle size of the rubbery polymer is used. This leads to a problem of deterioration of sex.

Therefore, in order to improve these drawbacks, a method of defining the rubber particle size distribution (JP-A-62-1714), a method of defining the composition of the matrix resin (JP-A-60-11514), etc. Proposed.

Also, a method of adding polysiloxane to a resin composition in which a small to medium particle diameter rubber and a large particle diameter rubber are combined (Japanese Patent Laid-Open No. 58-1
No. 7144) is also proposed.

<Problems to be Solved by the Invention> However, in the method described in JP-A-62-11714 and JP-A-60-11514, a resin composition satisfying both surface gloss and impact resistance is obtained. Can't get

Further, the method described in JP-A-58-17144 requires a rubber enlargement step for producing a large particle diameter rubber having an average particle diameter of 0.4 μm or more by an emulsion polymerization method, and therefore the operation is complicated. However, there is a drawback that the cost is high.

Further, a method of controlling the dispersed particle diameter of rubber by a lump-suspension method can be considered, but this method can only obtain a resin composition having a low rubber concentration and is costly.

Therefore, the problem of the present invention is that the surface of the molded article has high gloss,
It is intended to provide a resin composition having good impact resistance and low cost.

<Means for Solving the Problems> The present inventors have arrived at the present invention as a result of intensive studies to solve the above problems.

That is, in the present invention, the rubbery polymer particles (A) have an average particle size of 0.15 to 0.25 μm, and 80% by weight or more of them satisfy the following formula (I). In the presence of terax 10 to 60 parts by weight (solid content), aromatic vinyl monomer 10 to 90% by weight, vinyl cyanide monomer 1 to 50% by weight and unsaturated carboxylic acid alkyl ester 0 to 80 Graft copolymer obtained by polymerizing 40 to 90 parts by weight of a monomer mixture consisting of 50% by weight, (B) 80 to 40% by weight of an aromatic vinyl monomer and 20 to 60% by weight of a vinyl cyanide monomer % Of a copolymer obtained by polymerizing a monomer mixture of 10% by weight and (C) a liquid polyorganosiloxane, and 10 to 100 parts by weight of the above component (A) and 0 of the above component (B).
~ 90 parts by weight to a total of 100 parts by weight, the above (C) component
The present invention provides a high-gloss resin composition characterized by being compounded in an amount of 0.001 to 0.5 part by weight.

0.7 × M ≦ X ≦ 1.3 × M (I) (where M is the average particle diameter of rubber particles (μm),
X represents the rubber particle diameter (μm) here. ) As the diene rubber polymer which is a constituent of the graft copolymer (A) used in the present invention, a polymer or a copolymer containing a conjugated diene as a main component is suitable. Of these, the conjugated diene content is 75% by weight or more, especially 85% by weight.
The above is preferable. Specifically, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, isoprene rubber and the like can be used.

The average particle size of these diene rubbery polymer latexes is required to be in the range of 0.15 to 0.25 μm, particularly 0.17 to 0.22 μm.

Here, when the average particle size of the diene rubbery polymer latex is less than 0.15 μm, the impact resistance of the resin composition is poor, and conversely, when it exceeds 0.25 μm, the surface gloss is lowered, which is satisfactory. A resin composition cannot be obtained.

The diene rubbery polymer latex used here has an essential condition that 80% by weight or more of the polymer particles have a particle size distribution in a range satisfying the following formula (I).

0.7 × M ≦ X ≦ 1.3 × M (I) (where M is the average particle diameter of rubber particles (μm),
X represents the rubber particle diameter (μm) here. A resin composition having excellent impact resistance and high surface gloss can be obtained only when a rubber latex having a narrow particle size distribution satisfying the above formula (I) is used, and the object of the present invention is achieved. be able to.

The gel content of the diene rubber polymer latex is preferably 60% by weight or more in consideration of the surface gloss and impact resistance of the resulting composition. Here, the gel content refers to the weight fraction of the toluene insoluble content after coagulating and drying the rubber latex.

As a method for producing these diene rubbery polymer latexes, a usual emulsion polymerization method can be adopted.
The average particle size, the particle size distribution and the gel content can be set to desired ranges by precisely controlling the amount of polymerization water during polymerization, the amount of emulsifier, the amount of chain transfer agent, the polymerization temperature, the stirring speed and the polymerization time. It will be possible.

In the present invention, the monomer that is graft-polymerized in the presence of the diene rubber polymer latex is an aromatic vinyl monomer, a vinyl cyanide monomer and optionally an unsaturated carboxylic acid alkyl ester. It is a monomer mixture.

Aromatic vinyl monomers include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-
Examples thereof include butyl styrene, o-ethyl styrene, o-chlorostyrene and o, p-dichlorostyrene, with styrene being particularly preferred. These can use 1 type (s) or 2 or more types.

Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile and ethacrylonitrile, and acrylonitrile is particularly preferable.

As the unsaturated carboxylic acid alkyl ester, an acrylic acid ester and / or a methacrylic acid ester having an alkyl or substituted alkyl group having 1 to 6 carbon atoms is preferable, and one kind or two or more kinds can be used. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, (meth)
Examples include n-butyl acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, and 2-chloroethyl (meth) acrylate. Among them, methyl (meth) acrylate can be preferably used.

Here, the proportion of the aromatic vinyl-based monomer is 10 to 90% by weight, preferably 15 to 85% by weight, more preferably 20 to 82% by weight, and 10 to 90% by weight based on all the monomers. When it is out of the range, the impact resistance of the resin composition is deteriorated, which is not preferable.

The ratio of vinyl cyanide-based monomer is 1 to all monomers.
50% by weight, preferably 2 to 30% by weight, more preferably 4
If the amount is less than 1% by weight, the impact resistance of the resin composition deteriorates, and if the amount exceeds 50% by weight, the surface gloss of the resin composition deteriorates, which is not preferable.

If the unsaturated carboxylic acid alkyl ester is used in an amount of 80% by weight or less based on all the monomers, the object of the present invention can be achieved.

Further, the graft copolymer (A) is used in an amount of 10 to 60 parts by weight (in terms of solid content) of the diene rubber polymer Telax, preferably 25 to 55 parts by weight, and more preferably 30 to 50 parts by weight, based on the above-mentioned monomer. 90-40 parts by weight of the mixture of monomers, preferably 75-45
It can be obtained by emulsion graft polymerization using 70 parts by weight, more preferably 70 to 50 parts by weight.

If the diene rubbery polymer latex is less than 10 parts by weight (solid content conversion), the impact resistance of the resin composition is deteriorated,
If the amount exceeds 60 parts by weight (calculated as solid content), the surface gloss of the resin composition is remarkably lowered due to poor dispersion of the diene rubber polymer, which is not preferable.

Various methods can be adopted as a method of adding the components such as the monomer mixture, the emulsifier, the polymerization initiator and the chain transfer agent in the graft polymerization. That is, (1) a method in which the entire amount is added at the initial stage of polymerization, (2) a method in which a part is added in the initial stage and the rest is continuously added at a constant rate, and (3) 2
For example, a method of adding it in more than once is possible.

There are no particular restrictions on the types of emulsifier, polymerization initiator and chain transfer agent used, and reagents used in ordinary emulsion polymerization can be used. Typical emulsifiers include potassium rosinate, potassium stearate, potassium oleate, and the like, and polymerization initiators include a combination system of organic hydroperoxide and sugar-containing pyrophosphate-ferrous sulfate and persulfate, and the like. Examples of the chain transfer agent include alkyl thiol compounds.

The graft ratio of the graft copolymer (A) thus obtained is preferably from 30 to 100%, more preferably from 35 to 80% in order to obtain a high-gloss resin composition having excellent impact resistance. Graft ratio is the ratio of rubbery polymer and monomer mixture,
It can be controlled by adjusting the type and amount of the polymerization initiator, the chain transfer agent and the amount.

The intrinsic viscosity [η] (measured at 30 ° C.) of the methyl copolymer-soluble component of the graft copolymer (A) is preferably 0.25 to 0.6 dl / g, more preferably 0.3 to 0.55 dl / g. When it is within these ranges, the object of the present invention can be achieved.

Examples of the aromatic vinyl-based monomer that is a constituent of the copolymer (B) used in the present invention include styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, vinyltoluene, o-ethylstyrene, Examples thereof include o-chlorostyrene and o, p-dichlorostyrene, but styrene is particularly preferable. These can use 1 type (s) or 2 or more types.

Acrylonitrile as vinyl cyanide monomer,
Examples thereof include methacrylonitrile and ethacrylonitrile, with acrylonitrile being particularly preferred.

In addition, if necessary, a part of the aromatic vinyl-based monomer may be partially unsaturated carboxylic acid alkyl ester such as methyl (meth) acrylate and ethyl (meth) acrylate, maleimide, N-methylmaleimide, N-cyclohexyl. It may be substituted with a maleimide-based monomer such as maleimide or N-phenylmaleimide.

Here, the ratio of each component in the monomer mixture is 80 to 40% by weight of the aromatic vinyl-based monomer, preferably 75 to 60% by weight, more preferably 75 to 65% by weight. The amount of the system monomer is 20 to 60% by weight, preferably 24 to 40% by weight, more preferably 25 to 35% by weight.

If the amount of the vinyl cyanide-based monomer is less than 0% by weight, the impact resistance of the resin composition is poor, and if it exceeds 60% by weight, the surface gloss and color tone of the resin composition are deteriorated, which is not preferable.

The intrinsic viscosity [η] (methyl ethyl ketone solvent, measured at 30 ° C) of the copolymer (B) is preferably 0.35 to 0.6 dl / g, more preferably 0.4 to 0.55 dl / g.

The polymerization method of the copolymer (B) is not particularly limited, and known methods such as bulk polymerization method, solution polymerization method, suspension polymerization method and emulsion polymerization method can be used.

In the present invention, each of the polymers obtained as described above is graft copolymer (A) in an amount of 10 to 100 parts by weight, preferably 15 to 100 parts by weight, more preferably 20 to 100 parts by weight. (B) 0 to 90 parts by weight, preferably 0 to 85 parts by weight, more preferably 0 to 80 parts by weight, and the above (A) and (B)
It is necessary to mix them so that the total amount becomes 100 parts by weight. If the blending amount of the graft copolymer (A) is less than 10 parts by weight, the impact resistance of the resin composition deteriorates, which is not preferable.

Further, the proportion of the diene rubbery polymer in the resin composition is 5 to 30% by weight or less, preferably 10 to 20% by weight. If it is less than 5% by weight, the impact resistance of the resin composition is poor. When it exceeds 30% by weight, the rigidity and surface gloss of the resin composition are deteriorated, which is not preferable.

Further, in the present invention, 0.001 to 0.5 parts by weight, preferably 0.005 to 0.3 parts by weight of liquid polyorganosiloxane (C) is added to 100 parts by weight of the total amount of the graft copolymer (A) and the copolymer (B). As a result, the surface gloss is further increased and the impact resistance is also improved. Liquid polyorganosiloxane (C)
If the amount added is less than 0.001 part by weight, the effect of improving the surface gloss and impact resistance is not observed, while if it exceeds 0.5 part by weight, the rigidity of the molded article decreases, which is not preferable.

The liquid polyorganosiloxane (C) preferably has a viscosity at 25 ° C. of 100 c.s. to 20,000 cs.
If the viscosity is out of this range, the sufficient addition effect may not be exhibited. There is no structural limitation as long as it is a polyorganosiloxane within the above range, but use of polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylphenylsiloxane, etc. is recommended, and polydimethylsiloxane is particularly preferable.

The present invention uses a diene rubbery polymer latex having a specific particle size and particle size distribution to add a small amount of liquid polyorganosiloxane to a graft copolymer obtained by copolymerizing a specific monomer composition. A high-gloss resin composition having excellent impact resistance can be obtained without compounding a large particle diameter rubber, and a resin composition having the above characteristics can be manufactured at low cost.

There is no particular limitation on the method for producing the resin composition of the present invention. For example, the graft copolymer (A) and, if necessary, the copolymer (B) together with the liquid polyorganosiloxane (C) are used in a high-speed stirrer or the like. After uniform mixing,
Various methods such as a method of melt-kneading with a single-screw or multi-screw extruder having a sufficient kneading ability can be adopted.

Further, pigments and dyes, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants and plasticizers, antistatic agents and the like can be added depending on the purpose.

<Examples> In order to more specifically describe the present invention, examples and comparative examples will be described below, but these examples do not limit the present invention.

Unless otherwise specified, "part" means part by weight and "%" means% by weight.

 The method for analyzing the polymer properties of the present invention is shown below.

Particle size distribution of rubber latex: Measured by sodium alginate method.

Graft ratio: Acetone was added to a predetermined amount (m) of the graft copolymer, and the mixture was refluxed for 4 hours. Add this solution to 8,800 rpm (10,0 rpm
(00G) After centrifugation for 30 minutes, insoluble matter was passed through. This insoluble matter was dried under reduced pressure at 60 ° C. for 5 hours, and the weight (n) was measured.

 The graft ratio was calculated by the following formula.

Here, L: the rubber content of the graft polymer. The resin composition finally obtained was molded by an injection molding method, and then various physical properties were measured by the following test methods.

Izod impact strength: ASTM D-256 1/2 inch with notch
23 ℃ (kg / cm / cm) Surface gloss: Suga Test Instruments Co., Ltd. digital variable angle gloss meter UG
Using V-5D, the surface reflected light of the molded product at an incident angle of 60 degrees was measured.

Test piece: length 120 mm × width 80 mm × thickness 3 mm Reference Example 1 “Production of Graft Copolymer A” A diene rubbery polymer latex showing the rubber characteristics shown in Table 1 was charged in a glass reactor and further stirred. Meanwhile, glucose, sodium pyrophosphate, and ferrous sulfate dissolved in ion-exchanged water were charged, the inside of the vessel was replaced with nitrogen, and then the temperature in the reactor was raised to 65 ° C.

To this mixed solution, a predetermined amount of the monomer and normal octyl mercaptan mixture shown in Table 1 and an aqueous potassium oleate solution of cumene hydroperoxide were separately added dropwise continuously for 3.5 hours and 5 hours, respectively. After raising the inside temperature to 75 ° C. and further stirring for 1 hour to complete the reaction, 2,6-di-tert-butylparacresol was added as an antioxidant. The polymerization rate was 97.5%.

The obtained graft copolymer latex was coagulated with sulfuric acid, neutralized with NaOH, washed with water, dehydrated and dried to obtain a graft copolymer (A-1). This graph and the graft ratio of the copolymer are 45%, the intrinsic viscosity of the methyl ethyl ketone soluble component is 0.
It was 39 dl / g.

With the same formulation, the graft copolymers (A-2) to (A-
9) was obtained. Table 1 shows the graft ratio and the intrinsic viscosity of the methyl ethyl ketone-soluble component.

Reference Example 2 "Production of Copolymer B" B-1: A monomer mixture comprising 72% styrene and 28% acrylonitrile was suspension polymerized to produce a copolymer B-1. The intrinsic viscosity of the methyl ethyl ketone soluble component was 0.49.

B-2: A monomer mixture consisting of 75% styrene and 25% acrylonitrile was suspension polymerized to prepare a copolymer B-2. The intrinsic viscosity of the methyl ethyl ketone soluble component was 0.46.

Examples 1 to 12, Comparative Examples 1 to 5 Graft copolymer (A), copolymer (B) and liquid polyorganosiloxane (C) prepared in the above reference examples:
(Toray Silicone Co., Ltd.) were mixed at the mixing ratios shown in Table 2, and 1.0 part of ethylenebisstearylamide and 0.1 part of diphenylisodecylphosphite were further added and mixed with a Henschel mixer. Then 4
Extruded at a kneading temperature of 220 ° C. with a 0 mmφ extruder, pelletizing each, and then molding temperature of each pellet of 230 ° C.,
Each test piece was prepared by injection molding under a mold temperature of 60 ° C., and the physical properties of the test piece were evaluated. Table 2 shows the results.

The following is clear from the examples and comparative examples.

That is, the resin composition of the present invention (Examples 1-12),
In both cases, the surface of the molded product has high gloss and also has excellent impact resistance.

On the other hand, the average particle diameter of the rubbery polymer in the graft copolymer (A) deviates from the specified value (Comparative Example 2,
In 3), the surface gloss is lowered or the impact resistance is lowered.

Further, in the case where the rubber particle diameter distribution of the rubber-like polymer in the graft copolymer (A) does not satisfy the defined formula (Comparative Example 5), the surface gloss is lowered.

The composition without addition of liquid polyorganosiloxane (Comparative Example 4) is not a satisfactory composition because the impact resistance is greatly reduced and the surface gloss is also somewhat reduced.

When the blending ratio of the graft copolymer (A) is less than 10 parts by weight (Comparative Example 1), the impact resistance is significantly deteriorated.

<Effect of the Invention> The resin composition of the present invention shows a remarkable improvement in surface gloss without impairing the mechanical properties of the molded article, and is suitable as a molding material for exterior parts of household electric appliances. Is a graft copolymer (A) or a specific copolymer (B) in which the average particle size and particle size distribution of the dispersed rubber particles are defined.
It is only exhibited by mixing the liquid polyorganosiloxane (C) in a predetermined ratio.

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Claims (1)

[Claims] 1. The average particle diameter of the rubbery polymer particles (A) is 0.
15 to 0.25 μm, and 80% by weight or more of which is aromatic vinyl type in the presence of 10 to 60 parts by weight (based on solid content) of a diene rubbery polymer latex having a particle size distribution satisfying the following formula (I). Monomer 10 to 90% by weight, vinyl cyanide monomer 1
~ 50% by weight and unsaturated carboxylic acid alkyl ester 0
Graft copolymer obtained by polymerizing 40 to 90 parts by weight of a monomer mixture consisting of -80% by weight, (B) aromatic vinyl-based monomer
A copolymer obtained by polymerizing a monomer mixture of 80 to 40% by weight and a vinyl cyanide monomer of 20 to 60% by weight, and (C) a liquid polyorganosiloxane. For 100 parts by weight and a total of 100 parts by weight of the component (B), 0 to 90 parts by weight, 0.001 to 0.001 part of the component (C) is added.
A high-gloss resin composition comprising 0.5 part by weight. 0.7 × M ≦ X ≦ 1.3 × M (I) (where, M is the average particle diameter of rubber particles (μm), X
Indicates the rubber particle diameter (μm) here. )