JP2002179873A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having high and balanced transparency, chemical resistance and color stability. SOLUTION: The thermoplastic resin composition contains a rubber-containing graft copolymer dispersed in a vinyl copolymer. The ratio of the triple sequence of the acrylonitrile monomer unit existing in the acetone-soluble fraction of the thermoplastic resin composition is <=10 wt.% based on the acetone-soluble fraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber-containing styrene-based thermoplastic resin composition having transparency, and more particularly, to a rubber having excellent transparency, chemical resistance and color tone stability. The present invention relates to a styrene-based thermoplastic resin composition.

[0002]

2. Description of the Related Art A rubbery polymer such as a diene rubber contains a graft copolymer obtained by copolymerizing an aromatic vinyl compound such as styrene and α-methylstyrene and a vinyl cyanide compound such as acrylonitrile and methacrylonitrile. Transparent ABS resin has excellent mechanical strength balance such as transparency, impact resistance and rigidity, moldability and cost performance, so it is widely used in application fields such as home appliances, communication related equipment and general goods. Have been.

[0003] However, such transparent ABS resins are used in limited applications because of their low resistance to chemicals such as organic solvents and solvents such as detergents.

As means for improving the chemical resistance of these transparent ABS resins, it is generally known to increase the content of a vinyl cyanide compound, and various so-called high nitrile-containing thermoplastic resin compositions have been proposed. ing.

For example, in terms of improving chemical resistance,
Resin compositions having a specified graft ratio of the graft copolymer (JP-A-4-258609, JP-A-5-7842)
No. 8) and a high nitrile-containing thermoplastic resin composition containing a methacrylic acid ester as an essential component as a matrix component (Japanese Patent Application Laid-Open No. 4-126756).

However, in the above-mentioned conventional high-nitrile-containing thermoplastic resin composition, the reaction rates of the aromatic vinyl compound and the vinyl cyanide compound are different from each other.
It was difficult to obtain a polymer having a uniform composition. Therefore, a thermoplastic resin composition containing a copolymer of an aromatic vinyl compound and a vinyl cyanide compound tends to be colored yellow at the time of molding processing, and the quality has been deteriorated due to discoloration.

Therefore, at present, a high nitrile-containing thermoplastic resin composition having excellent balance of transparency, chemical resistance and color tone stability has not been obtained.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been achieved as a result of studying to solve the above-mentioned problems in the prior art, and is excellent in transparency, chemical resistance and color tone stability. And a rubber-containing styrene-based thermoplastic resin composition.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a vinyl copolymer obtained by polymerizing a vinyl monomer mixture was grafted onto a rubber-containing graft copolymer. Upon preparing a thermoplastic resin composition in which the coalesced particles are dispersed, when satisfying specific conditions, it has been found that a thermoplastic resin composition excellent in transparency, chemical resistance, and color tone stability can be obtained, The present invention has been reached.

That is, the thermoplastic resin composition of the present invention comprises 5 to 40% by weight of an aromatic vinyl monomer (a1) and 30 to 8 of an unsaturated carboxylic acid alkyl ester monomer (a2).
0% by weight, vinyl cyanide monomer (a3) 10 to 50
% By weight and other monomers copolymerizable therewith (a4)
Vinyl monomer mixture (a) containing 0 to 40% by weight
Graft copolymer (B) obtained by graft-polymerizing one or more vinyl monomers (c) in the presence of a rubbery polymer (b) onto a vinyl copolymer (A) obtained by polymerizing Is a thermoplastic resin composition obtained by dispersing the acrylonitrile monomer unit in the acetone-soluble component of the thermoplastic resin composition, wherein the ratio of the triple sequence of the acrylonitrile monomer unit is based on the acetone-soluble component. It is not more than 10% by weight.

In the thermoplastic resin composition of the present invention, the haze value is 30% or less, and the rubbery polymer component constituting the graft copolymer (B) and the acetone-soluble component are mixed. The difference in refractive index is within 0.03,
When the solubility parameter of the vinyl copolymer (A) is 1
0.5 to 12.5 (cal / ml) ^1/2 , that the vinyl copolymer (A) is produced by a suspension polymerization method, and that the vinyl copolymer (A ) Is produced by an emulsion polymerization method, and the vinyl copolymer (A) is a vinyl monomer mixture (a)
Of the vinyl cyanide monomer (a3) is added to the polymerization system before the polymerization conversion rate reaches 30%,
The polymerization conversion of at least 50% by weight of the aromatic vinyl monomer (a1), the unsaturated carboxylic acid alkyl ester monomer (a2) and the other monomer (a4) copolymerizable therewith is 10%. %, And the polymer is produced by adding and polymerizing the mixture after reaching the above-mentioned percentage, all of which are mentioned as preferable conditions. When these conditions are satisfied, it is possible to expect a further excellent effect.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, specific examples of the aromatic vinyl monomer (a1) used in the vinyl copolymer (A) include styrene, α-methylstyrene, p-methylstyrene, Vinyltoluene, t-butylstyrene,
o-ethylstyrene, o-chlorostyrene and o, p
-Dichlorostyrene and the like, and styrene and α-methylstyrene are particularly preferable. One or more of these can be used.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), 5 to 40% by weight, preferably 10 to 30% by weight of the aromatic vinyl monomer (a1) is used. Must be used in the range. If it is less than the above range, mechanical properties such as Izod impact strength and rigidity will be remarkably reduced, and if it is more than the above range, transparency will be remarkably reduced.

In the present invention, the vinyl copolymer (A)
Specific examples of the unsaturated carboxylic acid alkyl ester-based monomer (a2) used for (a) include methyl (meth) acrylate, ethyl (meth) acrylate, and n (meth) acrylate.
-Propyl, n-butyl (meth) acrylate, (meth)
Examples include t-butyl acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate and 2-chloroethyl (meth) acrylate, with methyl methacrylate being particularly preferred. . One or more of these can be used.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), 30 to 80% by weight of the unsaturated carboxylic acid alkyl ester monomer (a2) is used.
Preferably, it must be used in the range of 35 to 75% by weight. If it is less than the above range, it is difficult to obtain transparency, and if it exceeds the above range, the chemical resistance tends to be significantly reduced.

In the present invention, the vinyl copolymer (A)
Specific examples of the vinyl cyanide-based monomer (a3) used include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferable. One or more of these can be used.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), 10 to 50% by weight, preferably 12 to 4% by weight of the vinyl cyanide monomer (a3) is used.
It must be used in the range of 0% by weight. If it is less than the above range, the chemical resistance is remarkably reduced, and if it exceeds the above range, the desired color stability tends to be not obtained.

In the present invention, the vinyl copolymer (A)
The other copolymerizable monomer (a4) used for is not particularly limited, but includes acrylic acid, methacrylic acid, crotonic acid,
Polymerizable unsaturated carboxylic acids such as vinyl acetic acid, itaconic acid and maleic acid, maleimide compounds such as N-methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide, unsaturated dicarboxylic acids such as maleic acid, maleic anhydride and the like Examples thereof include unsaturated dicarboxylic anhydrides and unsaturated amides such as acrylamide. Among them, N-phenylmaleimide and maleic anhydride are preferably used.

In the present invention, the haze value of the thermoplastic resin composition must be 30% or less, preferably 15% or less. If it exceeds the above range, the transparency tends to be remarkably reduced.

In the vinyl monomer mixture (a) forming the vinyl copolymer (A), the other copolymerizable monomer (a4) is used in an amount of 0 to 40% by weight, Particularly, from the viewpoint of chemical resistance, it is used in the range of 0 to 30% by weight.

The vinyl monomer mixture (a) has a solubility parameter of the vinyl copolymer (A) of from 10.5 to 1
The composition of each monomer is selected so as to be 2.5 (cal / ml) ^1/2 . The definition of the solubility parameter here is shown in the following formula (1).

Δ = (ΣΔEi · X / ΣΔVm · X) ^1/2 (1) δ: Solubility parameter of vinyl-based copolymer (B) ((cal / ml) ^1/2 ) X: Vinyl-based copolymer Molar fraction (%) of the copolymer component constituting (B) ΔEi: evaporation energy (cal / mol) of the copolymer component constituting the vinyl copolymer (B) ΔVm: vinyl copolymer (B) The molecular volume (ml / mol) of the copolymer component constituting the above formula (1) and each numerical value of X, ΣΔEi, ΣΔVm Burrell, Offic. Dig. A.
J. Tortorello, M .; A. Kinsell
a, J. et al. Coat. Technol. It is quoted from. From the viewpoint of chemical resistance and mechanical properties of the thermoplastic resin composition, the solubility parameter of the vinyl copolymer (B) is preferably from 10.5 to 12.5 (cal / ml) ^1/2 . More preferably, 10.7-12.3 (cal /
ml) ^1/2 .

The polymerization method of the vinyl copolymer (A) is not particularly limited, but a suspension polymerization method or an emulsion polymerization method is preferably selected from the viewpoint of transparency and productivity. Hereinafter, an example of the manufacturing method will be described.

In the suspension polymerization or emulsion polymerization, a suitable non-solvent can be used as a dispersion medium for the vinyl monomer mixture (a), but it has good heat removal efficiency of polymerization heat and easy treatment after polymerization. So water is preferred.

There are no particular restrictions on the suspension stabilizer used in the suspension polymerization, but inorganic suspension stabilizers such as clay, barium sulfate and magnesium hydroxide, polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylamide, Organic suspension stabilizers such as methyl methacrylate / acrylamide copolymer and the like can be mentioned. Among them, organic suspension stabilizers are preferably used in view of color stability. One or two of these suspension stabilizers may be used.
Used in combination of more than one species.

The emulsifier used in the emulsion polymerization is not particularly limited, and various surfactants can be used. Anionic surfactants such as carboxylate type, sulfate type and sulfonate type are particularly preferable. used. Specific examples of such emulsifiers include caprylate, caprate,
Laurylate, mistyphosphate, palmitate, stearate, oleate, linoleate, linolenate, rosinate, behenate, castor oil sulfate, lauryl alcohol sulfate, and other higher grades Alcohol sulfate, dodecylbenzene sulfonate, alkyl naphthalene sulfonate, alkyl diphenyl ether disulfonate, naphthalene sulfonate condensate, dialkyl sulfosuccinate, polyoxyethylene lauryl sulfate, polyoxyethylene alkyl ether sulfate And polyoxyethylene alkyl phenyl ether sulfate. The salt herein refers to an alkali metal salt, an ammonium salt, and the like. Specific examples of the alkali metal salt include a potassium salt, a sodium salt,
Lithium salt and the like. These emulsifiers are
Species or two or more species are used in combination.

As the initiator used for the polymerization, a peroxide or an azo compound is used. Specific examples of the peroxide include benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butylcumyl peroxide, t-butylperoxyacetate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxide, t
-Butyl peroctate, 1,1-bis (t-butyl peroxy) 3,3,5-trimethylcyclohexane,
Examples thereof include 1,1-bis (t-butylperoxy) cyclohexane and t-butylperoxy-2-ethylhexanoate. Among them, cumene hydroperoxide and 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane are particularly preferably used. Specific examples of the azo compound include azobisisobutyronitrile, azobis (2,4 dimethylvaleronitrile), 2-phenylazo-2,4-dimethyl-
4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1,1'-azobiscyclohexane-1-carbonitrile, azobis (4-methoxy-
2,4-dimethylvaleronitrile), dimethyl 2,2 '
-Azobisisobutyrate, 1-t-butylazo-1-
Examples thereof include cyanocyclohexane, 2-t-butylazo-2-cyanobutane, and 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane. When using these initiators, one type or two or more types are used in combination. Among them, azobisisobutyronitrile is particularly preferably used.

In carrying out suspension polymerization or emulsion polymerization, a chain transfer agent such as mercaptan or terpene can be used for the purpose of controlling the degree of polymerization of the obtained vinyl copolymer (A). As a specific example, n-
Octyl mercaptan, t-dodecyl mercaptan, n
-Dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, terpinolene and the like. When these chain transfer agents are used, one type or two or more types are used in combination. Among them, n-octyl mercaptan, t-dodecyl mercaptan and n-dodecyl mercaptan are preferably used.

The reduced viscosity (ηsp / c) of the vinyl copolymer (A) in the present invention is not particularly limited.
-1.0 dl / g, particularly preferably in the range of 0.2-0.7 dl / g, from the viewpoint of the balance between impact resistance and moldability.

In the polymerization of the vinyl copolymer (A) used in the present invention, 50% by weight or more of the vinyl cyanide monomer (a3) is added to the polymerization system before the polymerization conversion reaches 30%. Is used, the acrylonitrile content in the residual monomer at the end of polymerization can be kept low, so that the ratio of the triple sequence of the acrylonitrile monomer unit in the acetone-soluble component of the thermoplastic resin composition is reduced. This is preferable because the color can be reduced and the color tone of the obtained thermoplastic resin is further improved. It is more preferable to add 70% by weight or more of the vinyl cyanide monomer (a3) into the polymerization system before the polymerization conversion reaches 30%.

The aromatic vinyl monomer (a1), the unsaturated carboxylic acid alkyl ester monomer (a2) and the other monomer (a4) copolymerizable therewith are 50% by weight. % Or more is preferably added after the polymerization conversion reaches 10%, more preferably 60% by weight.
It is preferable to add the above after the polymerization conversion reaches 10%. After the polymerization conversion reaches 10%, 50% by weight or more of an aromatic vinyl monomer (a1), an unsaturated carboxylic acid alkyl ester monomer (a2), and another monomer copolymerizable therewith. By adding the body (a4),
The concentration of the vinyl cyanide monomer in the system at the latter stage of the polymerization can be kept low, and the ratio of the triple sequence of acrylonitrile monomer units can be reduced.

The polymerization conversion rate as used herein refers to the measurement of unreacted monomers in a homogeneously mixed system, the subtraction of the amount of unreacted monomers from the amount of charged monomers, and calculation of the amount of converted polymer. It is a calculation of the ratio of the amount of converted polymer to the amount of monomer.

The rubbery polymer (b) used for the graft copolymer (B) in the present invention is not particularly limited.
Specific examples include polybutadiene, poly (butadiene-
Styrene), poly (butadiene-acrylonitrile),
Polyisoprene, poly (butadiene-butyl acrylate), poly (butadiene-methyl methacrylate), poly (butyl acrylate-methyl methacrylate), poly (butadiene-ethyl acrylate), ethylene-propylene rubber, ethylene-propylene- Diene rubber, poly (ethylene-isoprene), poly (ethylene-methyl acrylate) and the like. These rubbery polymers (b) are used alone or in a mixture of two or more. Among them, the use of polybutadiene, poly (butadiene-styrene), poly (butadiene-acrylonitrile), and ethylene-propylene rubber is preferable in terms of impact resistance.

The content of the rubbery polymer (b) constituting the graft copolymer (B) is not particularly limited.
The range of 0 to 80 parts by weight, particularly 35 parts by weight to 60 parts by weight is preferable. When the amount is less than 20 parts by weight, the impact strength of the obtained thermoplastic resin composition decreases, and when it exceeds 80 parts by weight, the melt viscosity increases. It is not preferable because moldability is deteriorated.

The weight average particle diameter of the rubbery polymer (b) is from 0.1 to 1.5 μm in view of the impact resistance, moldability, flowability and appearance of the thermoplastic resin composition obtained.
Preferably it is in the range of 0.15 to 1.2 μm.

The vinyl-based monomer mixture (c) constituting the graft copolymer (B) is not particularly limited. However, in order to obtain excellent transparency, the above-mentioned rubbery polymer (b) is grafted with the above-mentioned rubbery polymer (b). It is preferable to select the components so that the difference in the refractive index of the components is within 0.03, particularly within 0.01. Specific examples of the vinyl monomer mixture (c) include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, t-butylstyrene, o-ethylstyrene, o-chlorostyrene and o, p-dichlorostyrene. Aromatic vinyl monomers such as styrene, vinyl cyanide monomers such as acrylonitrile, methacrylonitrile and ethacrylonitrile and methyl (meth) acrylate, ethyl (meth) acrylate, n- (meth) acrylate Propyl, n-butyl (meth) acrylate, t-butyl (meth) acrylate,
Unsaturated carboxylic acid alkyl ester monomers such as n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate and 2-chloroethyl (meth) acrylate can be mentioned. Particularly, styrene, α-methylstyrene, acrylonitrile and methyl methacrylate are preferred. These may be used alone or in combination of two or more.

The reduced viscosity (ηsp / c) of the graft component constituting the graft copolymer (B) in the present invention is not particularly limited, but is preferably 0.05 to 1.2 dl / g, particularly 0.1.
It is preferable to be within the range of 0.7 dl / g from the viewpoint of the balance between impact resistance and moldability.

The graft ratio of the graft copolymer (B) is not limited, but is preferably 5 to 150% by weight from the viewpoint of impact resistance.
Preferably 10 to 100% by weight is used.

The method for producing the graft copolymer (B) is not limited, but preferably an emulsion polymerization method or a bulk polymerization method is employed. Above all, it is most preferable that the rubber component is produced by an emulsion polymerization method from the viewpoint of suppressing deterioration of the rubber component due to excessive heat history and coloring. There is no particular limitation on the method of charging the monomer, and the method is as follows: initial batch charging, continuous charging of part or all of the monomer to control the distribution of the copolymer composition, or monomer charging. A part or all may be charged separately. Normally, emulsion polymerization involves emulsion graft polymerization of a monomer mixture in the presence of a rubbery polymer latex. The emulsifier used in the emulsion graft polymerization is not particularly limited, and various surfactants can be used. Anionic surfactants such as carboxylate type, sulfate type, and sulfonate type are particularly preferably used. You. Specific examples of such an emulsifier include caprylate, caprate, laurate, mystyphosphate, palmitate,
Stearate, oleate, linoleate, linolenate, rosinate, behenate, castor oil sulfate, lauryl alcohol sulfate, other higher alcohol sulfate, dodecylbenzene sulfonate, alkyl Naphthalene sulfonate, alkyl diphenyl ether disulfonate, naphthalene sulfonate condensate, dialkyl sulfosuccinate, polyoxyethylene lauryl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, etc. Is mentioned. The salt herein refers to an alkali metal salt, an ammonium salt, and the like, and specific examples of the alkali metal salt include a potassium salt, a sodium salt, and a lithium salt. These emulsifiers are used alone or in combination of two or more.

Examples of the initiator and chain transfer agent which can be used in the emulsion graft polymerization include the initiators and chain transfer agents exemplified in the production of the copolymer (A). The initiator may be a redox type. used.

From the graft copolymer latex produced by emulsion graft polymerization, a coagulant is then added to coagulate the latex to recover the graft copolymer (B).
As the coagulant, an acid or a water-soluble salt is used, and specific examples thereof include sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, calcium chloride, magnesium chloride, barium chloride, aluminum chloride, magnesium sulfate, aluminum sulfate, aluminum ammonium sulfate, And potassium aluminum sulfate and sodium aluminum sulfate. These coagulants are used in one kind or in a mixture of two or more kinds.

The difference in refractive index between the rubbery polymer (b) constituting the graft copolymer (B) and the acetone-soluble component of the thermoplastic resin composition is not particularly limited. Therefore, it is preferably 0.03 or less, particularly preferably 0.01 or less. The acetone-soluble matter is the acetone-soluble matter of the composition contained in the supernatant liquid obtained by extracting the composition with acetone and separating it from the solid matter by a centrifuge or the like. The refractive index is a value measured using an Abbe refractometer. The difference in refractive index between the rubbery polymer (a) and the acetone-soluble component is 0.03.
If it exceeds, the transparency tends to be significantly reduced.

The mixing ratio of the graft copolymer (B) and the vinyl copolymer (A) constituting the thermoplastic resin composition of the present invention is not particularly limited, but is preferably a graft copolymer (B). 10 to 60 parts by weight, vinyl copolymer (A) 40
To 90 parts by weight, more preferably 20 to 50 parts by weight of the graft copolymer (B), and 50 to 50 parts by weight of the vinyl copolymer (A).
It is in the range of ~ 80 parts by weight. In addition, as long as the conditions of the refractive index and the solubility parameter are satisfied, a plurality of types of vinyl copolymers (A) can be used. If the amount of the graft copolymer (B) is less than 10 parts by weight or the amount of the vinyl copolymer (A) exceeds 90 parts by weight, the impact strength tends to decrease. On the other hand, when the amount of the graft copolymer (B) exceeds 60 parts by weight, the melt viscosity tends to increase and the moldability tends to deteriorate.

In the thermoplastic resin composition of the present invention, the proportion of the acrylonitrile monomer unit in the acetone-soluble component in the triple sequence is 10% by weight or less based on the acetone-soluble component. The triple sequence of acrylonitrile monomer units is a segment represented by the following formula (I) in a copolymer contained in an acetone-soluble component, and a copolymer having such a segment is heated to a high temperature. In the exposed state, the intramolecular cyclization reaction represented by the following formula (II) proceeds, which causes coloring.

[0045]

Embedded image

[0046]

Embedded image When the ratio of the triple sequence of acrylonitrile monomer units exceeds 10% by weight based on the acetone-soluble matter,
The resulting thermoplastic resin composition has poor color tone stability when melted. The ratio of the triple sequence is preferably less than 8% by weight and more preferably 5% by weight or less from the viewpoint of color tone stability. Such a thermoplastic resin composition in which the proportion of the acrylonitrile monomer unit in the acetone-soluble matter is controlled to 10% by weight or less is, for example, as described above, a triple sequence of acrylonitrile monomer units. Can be achieved by using a copolymer (A) in which the ratio of is controlled to 10% by weight or less.

The thermoplastic resin composition of the present invention contains vinyl chloride, polyethylene, and the like as long as the object of the present invention is not impaired.
Polyolefins such as polypropylene, polyamides such as nylon 6 and nylon 66, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polycyclohexanedimethyl terephthalate, polycarbonates and various elastomers can be added to improve the performance as a molding resin. In addition, if necessary, an antioxidant such as a hindered phenol type, a sulfur-containing organic compound type, a phosphorus-containing organic compound type, a heat stabilizer such as a phenol type or an acrylate type, a benzotriazole type, a benzophenone type, a salicylate type, etc. UV absorber,
Various stabilizers such as organic nickel-based and hindered amine-based light stabilizers; metal salts of higher fatty acids; lubricants such as higher fatty acid amides; plasticizers such as phthalic acid esters and phosphate esters; polybromodiphenyl ether; Halogen-containing compounds such as bromobisphenol-A, brominated epoxy oligomers, brominated polycarbonate oligomers, phosphorus compounds, flame retardants and flame retardant assistants such as antimony trioxide, antistatic agents, carbon black, titanium oxide, pigments and the like. A dye or the like can be added. Further, reinforcing agents and fillers such as glass fibers, glass flakes, glass beads, carbon fibers, and metal fibers can be added.

The thermoplastic resin composition of the present invention thus obtained has excellent balance of transparency, chemical resistance and color tone stability, balance of mechanical strength such as impact resistance and rigidity, moldability and cost performance. It can be widely used in application fields such as home appliances, communication-related equipment and general goods.

[0049]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, which do not limit the present invention. Unless otherwise specified, “%” indicates% by weight and “parts” indicates “parts by weight”. A method for analyzing the resin characteristics of the thermoplastic resin composition will be described below. (1) Weight average rubber particle diameter “Rubber Age Vol.88 p.484-
490 (1960) by E.I. Schmidt, P .;
H. Bidison "(using the fact that the particle size of polybutadiene to be creamed is different depending on the concentration of sodium alginate, the cumulative weight fraction of the creamed weight ratio and the cumulative weight fraction of the sodium alginate concentration is 50%. (Determination of particle diameter). (2) Graft ratio A predetermined amount (m; about 1 g) of the graft copolymer was added to acetone 2
Then, the mixture was refluxed for 3 hours in a water bath at 70 ° C., and the solution was cooled to 8800 rpm. p. m. After centrifugation at (10000 G) for 40 minutes, the insoluble matter was filtered, and the insoluble matter was
After drying under reduced pressure at 5 ° C. for 5 hours, the weight (n) was measured. The graft ratio was calculated from the following equation. Here, L is the rubber content of the graft copolymer.

Graft ratio (%) = ｛[(n)-(m) ×
L] / [(m) × L]｝ × 100 (3) Reduced viscosity (ηsp / c) of copolymer (A) A 0.4 g / 100 ml methyl ethyl ketone solution of a sample to be measured was measured using an Ubbelohde viscometer. Ηsp / c was measured at ° C. (4) Reduced viscosity of graft component (d) (ηsp / c) 200 ml of acetone was added to 1 g of the graft copolymer sample, and the mixture was refluxed for 3 hours in a 70 ° C. water bath.
00r. p. m. After centrifugation at (10000 G) for 40 minutes, the insoluble matter is filtered. The filtrate was concentrated with a rotary evaporator, and the precipitate (acetone-soluble matter) was dried under reduced pressure at 60 ° C. for 5 hours.
As a 00 ml methyl ethyl ketone solution, ηsp / c was measured at 30 ° C. using an Ubbelohde viscometer. (5) Polymerization conversion ratio Gas chromatograph (GC-14, manufactured by Shimadzu Corporation)
Unreacted monomer content was measured using A). The polymerization rate was calculated by the following equation: polymerization rate (% by weight) = (amount of charged monomer−amount of unreacted monomer) / amount of all monomers × 100 (6) Refraction of copolymer (A) and rubbery polymer (b) A small amount of 1-bromonaphthalene was dropped on a sample to be measured, and the refractive index was measured using an Abbe refractometer under the following conditions.

Light source: sodium lamp D line Measurement temperature: 20 ° C. (7) Refractive index of graft component (d) The precipitate obtained after drying under reduced pressure obtained by the same operation as in (4) above was used as a sample, The refractive index was measured in the same manner as in (1), and the measured value was taken as the refractive index of the graft component (d). (8) Triad sequence ratio of acrylonitrile monomer unit in acetone-soluble matter Using acetone-soluble matter obtained by the same operation as in (4) above as a sample, α of acrylonitrile monomer unit appearing in ¹³ C-NMR Taking advantage of the fact that the carbon signal shift is slightly different depending on the difference between adjacent monomer species, the ratio of the triple sequence is quantified from the signal integrated value, and the acrylonitrile monomer unit at the center of the triple sequence among all the monomer units And expressed as a weight fraction. The measurement conditions are as follows.

Apparatus: JEOL JNM-GSX400 type Observation frequency: 100.5 MHz Solvent: DMSO-d ₆ concentration: 445 mg / 2.5 mL Chemical shift standard: Me ₄ Si Temperature: 110 ° C. Observation width: 20000 Hz Data point: 32K flip angle : 90 ° (21 μs) pulsedelaytime: 5.0 s Number of accumulations: 7400 or 8400 Decoupling: gated decoupling (without NOE) Assignment of acrylonitrile sequence (A: acrylonitrile, S: styrene): -A-A-A-1
18.6 to 119.2 ppm -A-A-S- 119.3 to 120.2 ppm -S-A-S- 120.2 to 121.3 ppm (9) Acrylonitrile monomer in copolymer (A) Unit triple sequence ratio It was determined by the same operation as in (13) above, except that the copolymer (A) was used as a sample instead of the acetone-soluble component. (10) Transparency (Haze value) Toshiba Corporation pellets of the resin composition dried in an 80 ° C. hot air drier for 3 hours were set at a cylinder temperature of 250 ° C.
The haze value [%] of a square plate molded product (thickness: 3 mm) which was filled into an IS50A molding machine and molded immediately was measured by the Toyo Seiki Co., Ltd.
It measured using the direct reading haze meter. (11) Color tone (YI value) Measured according to JIS K7103. (12) Flexural modulus Measured according to ASTM D790 (23 ° C.). (13) Izod impact strength Measured according to ASTM D256 (23 ° C., with V notch). (14) Chemical resistance Press-formed test piece (127 × 12.7 × 1 mm)
Was fixed along the 1/4 elliptical jig shown in FIG. 1 and then 300 m in diameter containing 250 ml of Freon 141b.
The jig was placed in a desiccator of m. After standing at 23 ° C. for 24 hours, the presence or absence of cracks and cracks was confirmed, and the critical strain (%) was calculated by the following equation. % To 1.0%, ○ for 1.0% to 2.0%, and ◎ for more than 2.0%.

[0053]

(Equation 1) ε: Critical strain (%) a: Long axis of jig (mm) [127 mm] b: Short axis of jig (mm) [38 mm] t: Thickness of test piece (mm) [1.5 mm] X: Crack Reference point 1: Production of vinyl copolymer (A) [A-1]: 0.05 in a 20-liter autoclave.
Of a methyl methacrylate / acrylamide copolymer (described in Japanese Patent Publication No. 45-24151) was added to 165 parts of pure water, stirred at 400 rpm, and the system was replaced with nitrogen gas. Next, a mixed solution of 5 parts of acrylonitrile, 25 parts of styrene, 0.3 part of azobisisobutyronitrile and 0.5 part of t-dodecylmercaptan was added while stirring the reaction system, and the copolymerization reaction was carried out at 60 ° C. Was started, and the temperature was raised to 70 ° C. over 30 minutes. 3 from the start of polymerization
0 minutes later, methyl methacrylate was added to the solution using a feed pump.
0 parts were added. The polymerization addition rate at the start of the additional addition was 12% as a result. Thereafter, methyl methacrylate was added to the reaction system at 20 parts × 3 times at 30 minute intervals. After completion of the addition of all the monomers, the temperature was raised to 100 ° C. over 60 minutes. After controlling at 100 ° C. for 30 minutes after the arrival, cooling, separation of the polymer, washing, and drying were performed to obtain a bead copolymer.

The obtained acryl-based copolymer (A-1) had an acrylonitrile copolymerization amount of about 5%, a solubility parameter of 10.2 (cal / ml) ^1/2 and a reduced viscosity of 0.30.
dl / g, the triple sequence ratio was 2% by weight. [A-2]: Under the conditions of A-1, the amount of acrylonitrile and the amount of styrene in the mixed solution were 30 parts and 18 parts, respectively.
Department. Thirty minutes after the start of the polymerization, 12 parts of methyl methacrylate was added. The polymerization conversion rate at the start of the addition was 1
5%. Thereafter, at 30 minute intervals, 20 parts × 2 times of methyl methacrylate was added to the reaction system. Thereafter, polymerization was carried out in the same manner as in A-1 to obtain a bead copolymer.

The obtained acrylonitrile copolymer (A-2) had an acrylonitrile copolymerization amount of about 30%, a solubility parameter of 11.5 (cal / ml) ^1/2 , and a reduced viscosity of 0.3.
The 5 dl / g, triple sequence ratio was 3% by weight. [A-3] Among the conditions of the above A-1, the amount of acrylonitrile in the mixed solution was 30 parts and the amount of styrene was 10 parts. 30 minutes after the start of polymerization, acrylonitrile 30
Parts were added. At this time, the polymerization conversion was 10%. Thereafter, methyl methacrylate was added to the reaction system 15 times x twice at 30 minute intervals. Thereafter, polymerization was carried out in the same manner as in A-1 to obtain a bead copolymer.

The obtained acryl-based copolymer (A-3) had an acrylonitrile copolymerization amount of about 60%, a solubility parameter of 12.7 (cal / ml) ^1/2 , and a reduced viscosity of 0.4.
The 7 dl / g, triple sequence ratio was 21% by weight. [A-4] Under the conditions of the above A-1, the amount of acrylonitrile and the amount of styrene in the mixed solution are 30 parts and 18 parts, respectively.
Parts and the amount of methyl methacrylate were 52 parts. Part 18
The temperature was raised to 100 ° C over 0 minutes, and 100 minutes
Controlled at ° C. Thereafter, a beaded copolymer was obtained in the same manner as in A-1.

The obtained acrylonitrile copolymer (A-4) had an acrylonitrile copolymerization amount of about 30%, a solubility parameter of 11.5 (cal / ml) ^1/2 , and a reduced viscosity of 0.3.
The 2 dl / g, triple sequence ratio was 19% by weight. [A-5] Under the conditions of the above A-1, the amount of acrylonitrile in the mixed solution was 30 parts, and the amount of methyl methacrylate was 20 parts. 30 minutes after the start of polymerization, styrene 1
0 parts were added. At this time, the polymerization conversion was 11%. Thereafter, styrene was added to the reaction system at 20 parts × 2 times at intervals of 30 minutes. Thereafter, polymerization was carried out in the same manner as in A-1 to obtain a bead copolymer.

The obtained acrylonitrile copolymer (A5) had an acrylonitrile copolymerization amount of about 30%, a solubility parameter of 11.6 (cal / ml) ^1/2 , and a reduced viscosity of 0.35.
dl / g, the triple sequence ratio was 9% by weight. [A-6] Using the same reaction vessel as in the above A-1, 200 parts of pure water, 0.4 part of sodium formaldehyde sulfoxylate, and sodium ethylenediaminetetraacetate 0.1 part.
1. part, ferrous sulfate (0.01 part), 0.1 part of sodium phosphate and sodium laurate as an emulsifier
5 parts were charged into a reaction vessel, and the temperature was adjusted to 60 ° C. after replacement with nitrogen.
After adding a mixture of 30 parts of acrylonitrile, 10 parts of styrene, 0.3 part of n-dodecylmercaptan and 0.3 part of cumene hydroperoxide under stirring, the temperature was raised to 70 ° C. over 30 minutes. Thirty minutes after the start of polymerization, 12 parts of methyl methacrylate was added using a feed pump.
The polymerization addition rate at the start of the additional addition was measured and found to be 12%. Thereafter, methyl methacrylate was added to the reaction system twice at 15 minutes each at 30 minute intervals. After completion of the addition of all the monomers, the temperature was raised to 100 ° C. over 60 minutes. 10 minutes for 30 minutes after arrival
After controlling at 0 ° C., cooling, separation of the polymer, washing and drying were performed to obtain a bead copolymer.

The obtained acryl-based copolymer (A-6) had an acrylonitrile copolymerization amount of about 30%, a solubility parameter of 11.5 (cal / ml) ^1/2 and a reduced viscosity of 0.4.
The 2 dl / g, triple sequence ratio was 4% by weight. [Reference Example 2 Production of Graft Copolymer (B)] [B-1] Polybutadiene latex (rubber particle diameter of 0.1%).
50 parts (solid content), 200 parts of pure water, 0.4 parts of sodium formaldehyde sulfoxylate, 0.1 parts of sodium ethylenediaminetetraacetate
, Ferrous sulfate (0.01 part) and sodium phosphate (0.1 part) were charged into a reaction vessel, and after purging with nitrogen, the temperature was adjusted to 65 ° C, and 11.5 parts of styrene and acrylonitrile were stirred under stirring.
A mixture of 0 part, 34.5 parts of methyl methacrylate, and 0.3 part of n-dodecyl mercaptan was continuously added dropwise over 4 hours. At the same time, 0.25 part of cumene hydroperoxide and 2.5% of sodium laurate as an emulsifier
And a mixture of 25 parts of pure water were continuously added dropwise over 5 hours, and after the completion of the addition, the mixture was maintained for another 1 hour to complete the polymerization.

The latex after polymerization was coagulated with 1.5% sulfuric acid, then neutralized with sodium hydroxide, washed, centrifuged and dried to obtain a powdery graft copolymer.

The reduced viscosity of the graft component of the obtained graft copolymer (B-1) was 0.30 dl / g, and the graft ratio was 47% by weight. [B-2] Under the conditions of the above B-1, the amount of styrene in the mixture is 10 parts, the amount of acrylonitrile is 10 parts,
The amount of methyl methacrylate was 30 parts, and then B-1
A powdery graft copolymer was obtained in the same manner as described above.

The reduced viscosity of the graft component of the obtained graft copolymer (B-2) was 0.45 dl / g, and the graft ratio was 52% by weight. [Examples 1 to 4] The vinyl copolymers (A-2) and (A-6) produced in the above reference example and the graft copolymers (B-1) and (B-2) were prepared in the form of a table. After kneading with a Henschel mixer at the mixing ratio shown in 1, the mixture was extruded into a gut-like pellet at an extrusion temperature of 230 ° C by a 40 mmφ extruder. Next, the obtained pellets were injection-molded at a molding temperature of 230 ° C. and a mold temperature of 40 ° C. to prepare test pieces for evaluation.

Table 2 shows the results of measuring the properties of these test pieces.

[0064]

[Table 1]

[0065]

[Table 2] As is clear from the results of Tables 1 and 2, the thermoplastic resin compositions of Examples 1 to 4 of the present invention are excellent in balance in all of transparency, color tone stability and chemical resistance. [Comparative Examples 1 to 8] Vinyl copolymers (A-1), (A-3), (A-4) and (A-
5) and the graft copolymers (B-1) and (B-2)
Were kneaded with a Henschel mixer in the mixing ratio shown in Table 3, and then extruded into a gut-like pellet at an extrusion temperature of 230 ° C. using a 40 mmφ extruder. Next, the obtained pellets were injection-molded at a molding temperature of 230 ° C. and a mold temperature of 40 ° C. to prepare test pieces for evaluation.

Table 4 shows the results of measuring the properties of these test pieces.

[0067]

[Table 3]

[0068]

[Table 4] As can be seen from the results in Tables 3 and 4, in Comparative Examples 1 and 2, the content of the vinyl cyanide-based monomer in the vinyl-based copolymer was less than 10% by weight, so that the chemical resistance was poor. In Comparative Examples 3 and 4, the content of the vinyl cyanide monomer in the vinyl copolymer was more than 50% by weight,
Since the triple sequence ratio is higher than the specified range, the color tone stability is extremely poor. Comparative Examples 5 and 6 are also inferior in color tone stability due to a high triple sequence ratio. In Comparative Examples 7 and 8, since the copolymerization amount of the aromatic vinyl monomer in the vinyl copolymer was large and the copolymerization amount of the unsaturated carboxylic acid alkyl ester monomer was small, the vinyl copolymer The refractive index difference between the copolymer and the rubbery polymer was large, and the transparency was poor.

[0069]

As described above, the thermoplastic resin composition of the present invention is excellent in transparency, chemical resistance and color tone stability, and has a balance of mechanical strength such as impact resistance and rigidity. Since it is excellent in moldability and cost performance, it can be widely used in application fields such as home appliances, communication-related equipment and general miscellaneous goods.

[Brief description of the drawings]

FIG. 1 is a perspective view of a 1/4 elliptical jig used for evaluating chemical resistance.

[Explanation of symbols]

 1 1/4 ellipse jig 2 Test piece 3 Chemical solution coated surface 4 Crack X Distance from crack occurrence location

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 51/04 C08L 51/04 F term (Reference) 4J002 BC04W BC06W BC07W BG03W BG10W BN05X BN06X BN12X BN14X BN15X FD020 FD030 FD050 FD060 FD070 FD090 FD130 FD170 GC00 GQ00 4J011 AA05 AB07 BA03 BA04 BB01 BB05 BB09 JA03 JA05 JA06 JA07 JA08 KA02 KA04 KB14 KB19 NA01 PA54 PC02 PC06 PC07 4J100 DA02P AB03P AB04P AB08P AJ01 AM03 AJ08SAQ08

Claims (7)

[Claims] 1. An aromatic vinyl monomer (a1) 5 to 40.
%, 30 to 80% by weight of unsaturated carboxylic acid alkyl ester monomer (a2), 10 to 50% by weight of vinyl cyanide monomer (a3) and other monomers copolymerizable therewith ( a4) A vinyl copolymer (A) obtained by polymerizing a vinyl monomer mixture (a) containing 0 to 40% by weight is added to one or more vinyl copolymers in the presence of a rubbery polymer (b). A thermoplastic resin composition obtained by dispersing a graft copolymer (B) obtained by graft-polymerizing a system monomer (c), wherein acrylonitrile is present in an acetone-soluble component of the thermoplastic resin composition. A thermoplastic resin composition, wherein the ratio of a triple sequence of monomer units is 10% by weight or less based on the acetone-soluble matter. 2. The thermoplastic resin composition according to claim 1, wherein the haze value is 30% or less. 3. The difference in refractive index between the rubbery polymer component constituting the graft copolymer (B) and the acetone-soluble component is within 0.03. 3. The thermoplastic resin composition according to 2. 4. The vinyl-based copolymer (A) has a solubility parameter of 10.5-12.5 (cal / ml) ^1/2.
The thermoplastic resin composition according to any one of claims 1 to 3, wherein 5. The thermoplastic resin composition according to claim 1, wherein the vinyl copolymer (A) is produced by a suspension polymerization method. . 6. The thermoplastic resin composition according to claim 1, wherein the vinyl copolymer (A) is produced by an emulsion polymerization method. 7. The vinyl cyanide monomer (a) in the vinyl monomer mixture (a), wherein the vinyl copolymer (A) is
50% by weight or more of 3) is added to the polymerization system before the polymerization conversion reaches 30%, and the aromatic vinyl monomer (a1),
Polymerization by adding 50% by weight or more of the unsaturated carboxylic acid alkyl ester monomer (a2) and the other monomer copolymerizable therewith (a4) after the polymerization conversion reaches 10%. The thermoplastic resin composition according to any one of claims 1 to 6, wherein the thermoplastic resin composition is manufactured by the following method.