KR101050701B1 - Thermoplastic resin composition - Google Patents

Abstract

Provided is a thermoplastic resin composition having excellent transparency and a molded article having excellent impact resistance and molding processability even when the thickness is thin.

(I) Continuous phase 60-80 of a styrene- (meth) acrylic acid ester type copolymer which is a copolymer of a styrene monomer, a (meth) acrylic acid ester monomer, and the vinyl monomer copolymerizable with these monomers used as needed. Styrene- (meth) acrylic acid ester which is a copolymer of the styrene monomer, the (meth) acrylic acid ester monomer, and the vinyl monomer copolymerizable with these monomers used as needed to mass% and the (II) rubbery elastomer A rubber-modified styrene-based resin composition containing 40 to 20 mass% of the dispersed phase of the graft copolymer grafted with the copolymer, the volume average particle diameter of the dispersed phase is 0.3 to 0.6 µm, the weight average molecular weight (Mw) of the continuous phase, and its configuration X of Formula (1) calculated | required from a monomeric unit exists in the range of Formula (2), and 0.005-0.05 mass parts of organic polysiloxane with respect to 100 mass parts of this resin composition, Furthermore, the thermoplastic resin composition containing 0.1-2.5 mass parts of ester type lubricants as needed.

120000 ≤X ≤160000 (2)

Thermoplastic resin composition

Description

Thermoplastic composition {THERMOPLASTIC RESIN COMPOSITION}

The present invention relates to a thermoplastic resin composition in which a molded article having excellent transparency and exhibiting excellent impact resistance and molding processability can be obtained even if the thickness is very thin.

Conventionally, MBS polymers obtained by emulsion polymerization of two or more monomers selected from styrene, methyl methacrylate and acrylonitrile in rubbery polymer latex obtained by emulsion polymerization of butadiene and styrene or acrylonitrile and butadiene monomer mixture It is known that a thermoplastic resin composition excellent in impact resistance and transparency can be obtained by mixing with a rubber-modified styrene polymer (Japanese Patent Publication No. 46-32748). However, although these thermoplastic resin compositions are surely excellent in impact resistance, there existed a drawback that favorable transparency cannot be acquired depending on molding conditions.

In addition, in recent years, thinning of molded articles has been progressed, and even though the thickness is thin, the demand for high rigidity and excellent thin molding processability is very high. As a means to solve these problems, Japanese Unexamined Patent Publication No. 2001-226547 discloses a rubber-modified styrene resin composition composed of a continuous phase of a specific styrene- (meth) acrylic acid ester copolymer and a dispersed phase of a specific graft copolymer. Proposed. However, in a molded article having a very thin thickness, impact resistance or molding processability was not necessarily sufficient.

In view of such a phenomenon, the present invention provides a thermoplastic resin composition in which a molded article having excellent transparency and exhibiting excellent impact resistance and molding processability can be obtained even if the thickness is very thin.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve such a subject, the present inventors performed the rubber modified styrene resin composition which consists of the continuous phase of a specific styrene- (meth) acrylic-ester type copolymer, and the dispersed phase of a specific graft copolymer, The thermoplastic resin composition containing a specific amount of organic polysiloxane discovered that the said subject was solved, and came to complete this invention.

That is, this invention makes the following characteristics a summary.

1.Continuous phase 60 of a styrene- (meth) acrylic acid ester-based copolymer, which is a copolymer of (I) a styrene monomer, a (meth) acrylic acid ester monomer, and a vinyl monomer copolymerizable with these monomers, used as necessary. Styrene- (meth) which is a copolymer of a styrene monomer, a (meth) acrylic acid ester monomer, and the vinyl monomer copolymerizable with these monomers used as needed to -80 mass% and (II) rubbery elastomer. As a rubber modified styrene resin composition containing 40-20 mass% of the dispersed phase of the graft copolymer to which the acrylate ester copolymer was grafted,

The volume average particle diameter of a dispersed phase is 0.3-0.6 micrometer, X of Formula (1) calculated | required from the weight average molecular weight (Mw) of the continuous phase and its structural monomeric unit exists in the range of Formula (2), and this resin composition 100 mass The thermoplastic resin composition containing 0.005-0.05 mass parts of organic polysiloxane with respect to a part.

120000 ≤X ≤160000 (2)

2. Said rubber modified styrene resin composition contains 60-70 mass parts of continuous phases of (I) styrene- (meth) acrylic acid ester-type copolymer, and 40-30 mass% of the dispersing phases of (II) graft copolymers. The thermoplastic resin composition according to the above 1.

3. Thermoplastic resin composition as described in said 1 or 2 containing 0.1-2.5 mass parts of ester type lubricants with respect to 100 mass parts of rubber modified styrene resin compositions.

4. The thermoplastic resin composition according to item 3, wherein the ester lubricant is cured castor oil.

5. Thermoplastic resin composition in any one of said 1-4 whose organic polysiloxane is polydimethylsiloxane.

6. 20 to 70 mass% of styrene monomer units, 30 to 80 mass% of (meth) acrylic acid ester monomer units, and 0-10 mass% of vinyl monomer units copolymerizable with these monomers used as needed, and a continuous phase. The thermoplastic resin composition of any one of said 1-5 which is a styrene- (meth) acrylic-ester type copolymer which is a copolymer of the above.

7. 20-70 mass% of styrene-type monomeric units, 30-80 mass% of (meth) acrylic acid ester-type monomeric units in a dispersed phase for 30-80 mass parts of rubbery elastomers of a polybutadiene and / or a styrene-butadiene copolymer, And 1 to 5, wherein 20 to 70 parts by mass of a styrene- (meth) acrylic acid ester copolymer, which is a copolymer of a vinyl monomer unit copolymerizable with these monomers, which is used as necessary, is from 0 to 10% by mass. The thermoplastic resin composition according to any one of claims.

8. 20 to 70 mass% of styrene monomer units, 30 to 80 mass% of (meth) acrylic acid ester monomer units, and 0-10 mass% of vinyl monomer units copolymerizable with these monomers used as needed, and a continuous phase. Styrene- (meth) acrylic acid ester type copolymer which is a copolymer of 20-70 mass% of a styrene-based monomer unit, 30-80 mass parts of rubbery elastomers of a polybutadiene and / or a styrene-butadiene copolymer, Styrene- (meth) acrylic acid ester type copolymer 20 which is a copolymer of 30-80 mass% of (meth) acrylic acid ester type monomer units, and 0-10 mass% of vinylic monomer units copolymerizable with these monomers used as needed. The thermoplastic resin composition according to any one of 1 to 5, wherein the mass copolymer is a graft copolymer grafted to 70 parts by mass.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail. The styrene- (meth) acrylic acid ester-based copolymer constituting the continuous phase of the rubber-modified styrene-based resin composition of the present invention is a styrene-based monomer, a (meth) acrylic acid ester-based monomer, and copolymerized with these monomers used as necessary. Copolymers of possible vinyl monomers.

Moreover, the graft copolymer which comprises the dispersed phase of the rubber modified styrene resin composition of this invention is copolymerizable with these monomers used for a styrene type monomer, a (meth) acrylic acid ester type monomer, and as needed to a rubbery elastomer. A grafted grafted copolymer of a styrene- (meth) acrylic acid ester copolymer, which is a copolymer of a vinyl monomer.

Styrene-based monomers used in the continuous and disperse phase of the present invention may include styrene-α-methylstyrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, ethylstyrene, pt-butylstyrene, and the like. Preferably styrene. Although these styrene monomers may be individual, you may use 2 or more types together.

As the (meth) acrylic acid ester monomer used in the present invention, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate and 2-ethylhexyl methacrylate, methyl acrylate and ethyl acryl Acrylic acid esters such as acrylate, n-butyl acrylate, 2-methylhexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, and the like, but preferably methyl methacrylate or n-butyl acrylate, Especially preferably, it is methyl methacrylate. These (meth) acrylic acid ester monomers may be used alone or in combination of two or more thereof.

Moreover, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, N-phenylmaleimide, N-cyclohexyl maleimide etc. are mentioned as a vinyl monomer copolymerizable with these monomers used as needed. .

Examples of the rubbery elastomer used in the present invention include polybutadiene, styrene-butadiene block copolymers, and styrene-butadiene random copolymers.

The styrene monomer unit amount in the styrene-butadiene block copolymer or the styrene-butadiene random copolymer is preferably 60 mass% or less, particularly preferably 25 mass% or less (but 0 is not contained). It is preferable in order to obtain the favorable impact resistance and transparency of a modified styrene resin composition.

The rubber modified styrene resin composition of this invention contains 60-80 mass% of continuous phases of a styrene- (meth) acrylic acid ester type copolymer, and 40-20 mass% of the dispersed phases of a graft copolymer, Preferably it is styrene- It contains 60-70 mass% of continuous phases of a (meth) acrylic acid ester-type copolymer, and 40-30 mass% of the dispersed phases of a graft copolymer. If the dispersed phase of the graft copolymer is less than 20% by mass, the impact resistance in the thin molded article is insufficient, and if it exceeds 40% by mass, the molding processability is insufficient, which is not preferable.

In addition, the measurement of the mass ratio of the continuous phase and the dispersed phase was carried out by stirring the rubber-modified styrene resin composition (referred to as mass A) for 24 hours at a temperature of 23 ° C. in methyl ethyl ketone (MEK), and then using an centrifuge to remove the insoluble content to MEK. What is isolate | separated and vacuum-dried is measured by mass (mass is called B), and is calculated | required by following Formula (3) and Formula (4).

In addition, the volume average particle diameter of the dispersed phase of the graft copolymer is preferably 0.3 to 0.6 µm, particularly preferably 0.3 to 0.45 µm. If the volume average particle size is less than 0.3 µm, the impact resistance of the thin molded article is insufficient, and if it exceeds 0.6 µm, the transparency is poor, which is not preferable.

Moreover, as for the continuous phase of the said styrene- (meth) acrylic acid ester type copolymer, X of Formula (1) calculated | required from a weight average molecular weight (Mw) and its structural unit needs to exist in the range of Formula (2). However, the weight average molecular weight of the continuous phase described here is the weight average molecular weight of polystyrene conversion which measured the MEK soluble part of said rubber modified styrene resin composition by the gel permeation chromatography (GPC) method.

120000 ≤X ≤160000 (2)

If X is less than 120000, the impact resistance in the thin molded article is insufficient, and if it exceeds 160000, the molding processability is insufficient, which is not preferable. Especially, 12500 <= X <= 15500 are especially preferable.

The amount of each monomer unit constituting the continuous styrene- (meth) acrylic acid ester copolymer is not particularly limited as long as the above conditions are satisfied, but the styrene monomer unit is preferably 20 to 70% by mass, particularly preferably Is a vinyl monomer copolymerizable with 20 to 40 mass%, (meth) acrylic acid ester monomer unit, preferably 30 to 80 mass%, particularly preferably 60 to 80 mass%, and if necessary, these monomers. The unit is preferably 0 to 10% by mass, particularly preferably 0 to 5% by mass.

In addition, the rubbery elastic body constituting the dispersed graft copolymer and the amount of each monomer unit are not particularly limited as long as the above conditions are satisfied, but the following are preferable. That is, 30-80 mass parts of rubbery monomers, Preferably it is 50-75 mass parts, Especially preferably, 50-70 mass parts, Styrene-type monomer unit becomes like this. Preferably it is 20-70 mass%, Especially preferably, 20-40 mass%, (meth) acrylic acid ester monomeric unit 30-80 mass%, Especially preferably, 60-80 mass%, The vinylic monomer unit copolymerizable with these monomers used as needed is preferable. Is 20 to 70 parts by mass of styrene- (meth) acrylic acid ester copolymer containing 0 to 10% by mass, particularly preferably 0 to 5% by mass, preferably 25 to 50 parts by mass, particularly preferably 30 to Graft copolymers grafted with 50 parts by mass are preferably used.

The rubber modified styrene resin composition of this invention can be manufactured by well-known techniques, such as a block polymerization method, a solution polymerization method, suspension polymerization method, a block-suspension polymerization method, an emulsion polymerization method. Moreover, any method of a palindrome polymerization method and a continuous polymerization method can be used.

The thermoplastic resin composition of this invention contains an organic polysiloxane. Examples of the organic polysiloxanes include polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, and the like, but are preferably polydimethylsiloxane. Moreover, the modification type in which an epoxy group, an amino group, a carboxyl group, a hydroxyl group, a methacryl group, etc. were introduce | transduced in the terminal or molecule | numerator of organic polysiloxane can also be used as needed. Although these organic polysiloxanes may be used independently, you may use 2 or more types together.

In the thermoplastic resin composition of the present invention, it is preferable to use the organic polysiloxane and the ester type lubricant together in order to improve the balance between transparency, impact resistance and molding processability. Examples of the ester lubricant include fatty acid polyhydric alcohol esters such as hardened castor oil, fatty acid lower alcohol esters such as butyl stearate, and fatty acid polyglycol esters such as polyethylene glycol monostearate, and particularly preferably hardened castor oil.

Content of an organic polysiloxane is 0.005-0.05 mass parts with respect to 100 mass parts of rubber modified styrene resin compositions, Preferably it is 0.01-0.03 mass parts. If it is less than 0.005 mass part, the impact resistance in a thin molded article is insufficient, and when it exceeds 0.05 mass part, transparency will worsen and it is unpreferable.

Preferable content of an ester type lubricant is 0.1-2.5 mass parts with respect to 100 mass parts of rubber modified styrene resin compositions, Preferably it is 0.5-2 mass parts. If it is less than 0.1 mass part, the combined effect of organic polysiloxane and ester type lubricant will be small, and when it exceeds 2.5 mass parts, the fall of transparency will increase.

In the thermoplastic resin composition of the present invention, additives such as known antioxidants, weathering agents, lubricants, plasticizers, colorants, antistatic agents and mineral oils may be blended in a range that does not impair the performance of the thermoplastic resin composition of the present invention.

The thermoplastic resin composition of the present invention thus obtained can be processed into various molded bodies by methods such as injection molding, compression molding, and extrusion molding, and can be provided for practical use. There is no restriction | limiting in particular also about the mixing | blending (mixing) and the melt-extrusion method in the case of manufacturing various molded objects using the thermoplastic resin composition of this invention, A well-known method can be employ | adopted. For example, each raw material is uniformly mixed in advance by a tumbler, Henschel mixer, or the like, and fed to a single screw extruder or a twin screw extruder to melt mixing to prepare pellets for molding, and the pellets are molded to produce various molded articles.

Next, an Example is given and this invention is demonstrated further more concretely, but this invention is not limited to these examples.

First, it shows from manufacture of raw material resin.

(A) Preparation of styrene- (meth) acrylic acid ester copolymer

Reference Example 1: Styrene- (meth) acrylic acid ester copolymer A-1

Into a 250-liter autoclave, 100 kg of pure water, 0.5 g of sodium dodecylbenzenesulfonate, 250 g of tricalcium phosphate, 23 kg of styrene, 73 kg of methyl methacrylate, and 4 kg of acrylonitrile were placed and t-butyl as a polymerization initiator. 100g of peroxyisobutylate and 650g of t-dodecyl mercaptans were added, and the liquid mixture was disperse | distributed under stirring of rotation speed 150rpm. And this mixed liquid was heat-polymerized at 90 degreeC for 8 hours and 130 degreeC for 2.5 hours. After completion of the reaction, washing, dehydration and drying were carried out to obtain a beads of styrene- (meth) acrylic acid ester copolymer A-1.

Reference Example 2: Styrene- (meth) acrylic acid ester copolymer A-2

In Reference Example 1, except that the t-dodecyl mercaptan was changed to 800 g, it was prepared in the same manner as the styrene- (meth) acrylic acid ester copolymer A-1, and the beads were a styrene- (meth) acrylic acid ester copolymer. A-2 was obtained.

Reference Example 3: Styrene- (meth) acrylic acid ester copolymer A-3

In Reference Example 1, except that the t-dodecyl mercaptan was changed to 500 g, it was produced in the same manner as the styrene- (meth) acrylic acid ester copolymer A-1, and the styrene- (meth) acrylic acid ester copolymer in the form of beads A-3 was obtained.

Reference Example 4: Styrene- (meth) acrylic acid ester copolymer A-4

In Reference Example 1, except that the t-dodecyl mercaptan was changed to 900 g, the styrene- (meth) acrylic acid ester copolymer was prepared in the same manner as the styrene- (meth) acrylic acid ester copolymer A-1, and the beads were styrene- (meth) acrylic acid ester copolymer. A-4 was obtained.

Reference Example 5: Styrene- (meth) acrylic acid ester copolymer A-5

100 kg of pure water, 0.5 g of sodium dodecylbenzenesulfonate, 250 g of tricalcium phosphate, 42 kg of styrene, and 58 kg of methyl methacrylate were placed in a 250-liter autoclave, and t-butylperoxy isobutylate was added as a polymerization initiator. 100 g and t-dodecyl mercaptan 300g were added, and the liquid mixture was disperse | distributed under stirring of rotation speed 150rpm. And this mixed liquid was heat-polymerized at 90 degreeC for 8 hours and 130 degreeC for 2.5 hours. After completion of the reaction, washing, dehydration and drying were carried out to obtain a beads of styrene- (meth) acrylic acid ester copolymer A-5.                 

Reference Example 6: Styrene- (meth) acrylic acid ester copolymer A-6

In Reference Example 5, except that the t-dodecyl mercaptan was changed to 600 g, it was produced in the same manner as the styrene- (meth) acrylic acid ester copolymer A-5, and the styrene- (meth) acrylic acid ester copolymer in the form of beads A-6 was obtained.

(B) Preparation of rubbery elastomer latex

Reference Example 7 Rubber-like Elastic Latex G-1

To the 200-liter autoclave, 56 kg of pure water, 400 g of potassium oleate, 1200 g of potassium rosinate, 1.2 kg of potassium carbonate, and 400 g of potassium persulfate were added and dissolved uniformly under stirring. Subsequently, 400 g of t-dodecyl mercaptan and 80 kg of butadiene were added, and the mixture was polymerized at a temperature of 60 ° C. for 30 hours while stirring, and further heated to 70 ° C. for 30 hours to complete polymerization, thereby completing the rubbery elastomer latex G-1. Got it.

Reference Example 8 Rubber-like Elastic Latex G-2

To the 200-liter autoclave, 56 kg of pure water, 400 g of potassium oleate, 1200 g of potassium rosinate, 1.2 kg of potassium carbonate, and 400 g of potassium persulfate were added and dissolved uniformly under stirring. Subsequently, 400 g of t-dodecyl mercaptan, 23.6 kg of styrene, and 56.4 kg of butadiene were added, and the mixture was stirred at a temperature of 60 ° C. for 24 hours while stirring, and further heated to 70 ° C. for 24 hours to complete the polymerization. G-2 was obtained.

Reference Example 9: Rubbery Elastic Latex G-3

To a 200-liter autoclave, 64 kg of pure water, 400 g of potassium oleate, 1200 g of potassium rosinate, 1.2 kg of potassium carbonate, and 400 g of potassium persulfate were added and dissolved homogeneously under stirring. Subsequently, 400 g of t-dodecyl mercaptan, 23.6 kg of styrene, and 56.4 kg of butadiene were added, and the mixture was polymerized at a temperature of 60 ° C. for 16 hours while stirring, and further heated to 70 ° C. for 12 hours to complete the polymerization. G-3 was obtained.

Reference Example 10 Rubber-like Elastic Latex G-4

To a 200-liter autoclave, 115 kg of pure water, 500 g of potassium oleate, 75 g of sodium pyrolate, 1.5 g of ferrous sulfate, 2.2 g of sodium ethylenediaminetetraacetate, and 22 g of rongalit were added and dissolved homogeneously under stirring. Subsequently, 14.5 kg of styrene, 35.5 kg of butadiene, 148 g of t-dodecyl mercaptan, 30 g of divinylbenzene, and 96 g of diisopropylbenzene hydroperoxide were added, and the mixture was reacted at a temperature of 50 ° C. for 16 hours while stirring to complete polymerization. Elastic latex was obtained. After adding 45 g of sodium sulfosuccinate to the obtained rubber-like elastomer latex and sufficiently stabilizing, 0.2 mass% aqueous hydrochloric acid solution and 2 mass% caustic soda aqueous solution are added from each nozzle so that the pH of the latex is maintained at 8-9. And latex were coagulated and the rubbery elastomer latex G-4 with a volume average particle diameter of 0.6 micrometer was obtained.

(C) Preparation of Graft Copolymer-Containing Polymer

Reference Example 11: Graft Copolymer-Containing Polymer B-1

The rubbery elastomer latex G-1 of Reference Example 7 was weighed in terms of solid content, was transferred to a 200-liter autoclave, 90 kg of pure water was added, and the temperature was raised to 50 ° C. under nitrogen stream while stirring. To this was added 1.5 g of ferrous sulfate, 3 g of ethylenediaminetetraacetic acid sodium acetate and 3 g of rongalite dissolved in 2 kg of pure water, a mixture of 7.5 kg of styrene, 22.5 kg of methyl methacrylate and 60 g of t-dodecyl mercaptan; , 60 g of diisopropyl benzene hydroperoxide and 450 g of potassium oleate were continuously added to each of 8 kg of pure water over 6 hours. After completion of the addition, the temperature was raised to 70 ° C., 30 g of diisopropylbenzene hydroperoxide was further added, and the mixture was left for 2 hours to complete polymerization.

After adding antioxidant to the obtained emulsion and diluting solid content to 15 mass% with pure water, it heated up at the temperature of 70 degreeC, added diluted sulfuric acid with vigorous stirring, and performed salting, and after that, the temperature was raised to 95 degreeC and solidified It was then dehydrated, washed with water and dried to obtain a powdery graft copolymer-containing polymer B-1.

Reference Example 12 Graft Copolymer-Containing Polymer B-2

The rubbery elastomer latex G-2 of Reference Example 8 was weighed in terms of solids, weighed 30 kg, and transferred to a 200-liter autoclave, followed by adding 90 kg of pure water, 1.8 kg of styrene, and 4.2 kg of methyl methacrylate, under stirring with nitrogen. The temperature was raised to 50 ° C. To this, 1.5 g of ferrous sulfate, 3 g of ethylenediaminetetraacetic acid sodium acetate, and 3 g of rongalite were dissolved in 2 kg of pure water. A solution of 60 g of diisopropylbenzene hydroperoxide and 450 g of potassium oleate dispersed in 8 kg of pure water was continuously added for 6 hours. After completion of the addition, the temperature was raised to 70 ° C., 30 g of diisopropylbenzene hydroperoxide was further added, and the mixture was left for 2 hours to complete polymerization.

Antioxidant was added to the obtained emulsion, the solid content was diluted to 15 mass% with pure water, and it heated up at the temperature of 70 degreeC, diluted sulfuric acid was added with vigorous stirring, salting was performed, and the temperature was raised to 95 degreeC, and it solidified. It was then dehydrated, washed with water and dried to obtain a powdery graft copolymer-containing polymer B-2.

Reference Example 13: Graft Copolymer-Containing Polymer B-3

In Reference Example 12, except that the rubbery elastomer latex was changed to the rubbery elastomer G-3, it was produced in the same manner as the graft copolymer-containing polymer B-2 to obtain a powdery graft copolymer-containing polymer B-3.

Reference Example 14 Graft Copolymer-Containing Polymer B-4

In Reference Example 12, except that the rubbery elastomer latex was changed to the rubbery elastomer G-4, it was produced in the same manner as the graft copolymer-containing polymer B-2 to obtain a powdery graft copolymer-containing polymer B-4.

Examples 1-11 and Comparative Examples 1-9

Styrene- (meth) acrylic acid ester copolymers prepared in Reference Examples 1 to 6, graft copolymer-containing polymers prepared in Reference Examples 11 to 14, polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., KF-96) , Cured castor oil (Kao Wax 85-P manufactured by KAO Co., Ltd.), and ethylene bis stearic acid amide (Kao Wax EB-P manufactured by KAO Co., Ltd.) were blended in the ratios shown in Tables 1 and 2. Subsequently, this blend was mixed with a Henschel mixer and melt-kneaded at a cylinder temperature of 220 ° C. with a twin screw extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.) to pelletize. Using the obtained sample pellet, various physical properties were measured according to the following physical property measuring method. The measured values are shown in Table 1 and Table 2.                 

(1) Moldability in Thin Film Forming

Using an injection molding machine (NEOMAT515 / 150) manufactured by Sumitomo Heavy Industries, Ltd., the sample pellets were formed into square plates having a size of 200 x 200 x 1.5 mm under the following conditions 1 and 2. Moldability was evaluated.

Condition 1: Cylinder temperature 190 ° C, mold temperature 40 ° C

Condition 2: Cylinder Temperature 200 ℃, Mold Temperature 60 ℃

(Double-circle): The molded article of a favorable external appearance in both condition 1 and condition 2 was obtained.

(Circle): The molded article of a favorable external appearance was obtained in either condition 1 or condition 2.

X: Molding defects, such as a poor filling, gas burn, and a ripple-shaped flow mark, generate | occur | produced and the molded article of a favorable external appearance was not able to be obtained in both conditions 1 and 2.

(Circle) and (circle) were judged the pass.

(2) impact resistance of thin molded products

Using pellet injection machine (SYCAP165 / 75) manufactured by Sumitomo Heavy Industries, Ltd., sample pellets were molded under conditions of a cylinder temperature of 220 ° C. and a mold temperature of 60 ° C., and a rectangular plate having a dimension of 90 × 90 × 1 mm. The test piece was prepared. With respect to this test piece, the weight of 50 g of mass and 100 g of mass was dropped from 50 cm in height by the DuPont fall impact tester, and the impact resistance of the thin molded article was evaluated.

A: specific gravity of 80% or more due to the weight of 100 g

B: specific gravity of 80 g or more by weight of 50 g                 

C: less than 80% of the specific breaking rate by the weight of 50g

A and B were judged as passing.

(3) transparency (blur)

Sample pellets were molded under the conditions of a cylinder temperature of 220 ° C. and a mold temperature of 60 ° C. using an injection molding machine (IS-50EP) manufactured by Toshiba Machinery Co., Ltd., to prepare a square plate test piece having a size of 55 × 90 × 3 mm. It was. About this test piece, the cloudiness was measured based on ASTMD1003 (unit:%).                 

In addition, the analysis of a rubber modified styrene resin composition uses the pellet of the rubber modified styrene resin composition which mixed the styrene- (meth) acrylic acid ester type copolymer and the graft copolymer containing polymer in the compounding ratio of Table 1, Table 2 previously. Each analysis value was measured according to the following measuring method using this. Each analysis value is shown in Table 1, Table 2.

(1) Measurement of mass ratio of continuous phase and dispersed phase

The sample pellet (mass is A) previously weighed was stirred for 24 hours at 23 ° C. in methyl ethyl ketone (MEK), and then the insoluble matters were separated from the MEK by centrifugation, followed by centrifugation. It left to stand 30 minutes after operation. The operating conditions of the centrifuge are as follows.

Temperature: -9 ℃

RPM: 20000rpm

Time: 60 minutes

The supernatant and the precipitate of the centrifuged solution are separated, and the precipitate is dried with a vacuum dryer, and then weighed (mass is B). The mass ratio of the continuous phase and the dispersed phase is given by the following equation (3) and equation (4). Was obtained.

(2) Weight average molecular weight measurement of continuous phase

The supernatant of the centrifuged solution was collected and methanol was added to precipitate a styrene- (meth) acrylic acid ester copolymer (continuous phase). This precipitate was collected and measured by the GPC measurement conditions described below.

Device Name: SYSTEM-21 Shodex (manufactured by Showa Denko Co., Ltd.)

Column: 3 series of PL gel MIXED-B

Temperature: 40 ℃

Detection: Preview Refractive Index

Solvent: Tetrahydrofuran

Concentration: 2 mass%

Calibration curve: It produced using standard polystyrene (PS) (made by PL company), and the weight average molecular weight was shown by PS conversion value.

(3) Measurement of constituent monomer units in continuous phase

FT-NMR (FX-90Q type manufactured by Nippon Electronics Co., Ltd.) was dissolved by dissolving the continuous phase (MEK soluble component) composed of the styrene- (meth) acrylic acid ester copolymer obtained in the pretreatment measured in chloroform- d . It used and calculated | required the structural monomer unit.

(4) Volume average particle diameter measurement of dispersed phase

About 1 g of sample pellet was stirred for 24 hours in 100 g of N, N-dimethylformamide (DMF), and further diluted to the appropriate concentration by adding DMF again, using a laser diffraction scattering method particle size distribution analyzer (type LS230, COULTER Co., Ltd.). Measured.                 

(5) Ratio of structural monomer units in the dispersed phase

Each sample powder of the graft copolymer-containing polymer prepared in Reference Examples 11 to 14 was stirred in methyl ethyl ketone (MEK) at a temperature of 23 ° C. for 24 hours, after which an insoluble matter for MEK was separated by a centrifugal separator and centrifuged. It left to stand 30 minutes after operation. The operating conditions of the centrifuge are as described above.

The supernatant of the centrifuged solution was aliquoted, methanol was added, and the grafted styrene- (meth) acrylic acid ester copolymer was precipitated. This deposit was extract | collected, it melt | dissolved in heavy chloroform, and the structural monomer unit was calculated | required using FT-NMR (FX-90Q type by Nippon Electronics Co., Ltd.).

Further, in the graft copolymer-containing polymer prepared in Reference Examples 11 to 14, the ratio of the constituent monomer units of the styrene- (meth) acrylic acid ester copolymer grafted to the rubbery polymer and the grafted styrene- (meth Since the ratio of the structural monomer unit of the) acrylic acid ester type copolymer can be considered to be the same, this measurement value was made into the ratio of the structural monomer unit of the styrene- (meth) acrylic acid ester type copolymer grafted to the rubbery polymer.

(6) Measurement of the amount of rubbery elastomer and the amount of graft monomer in dispersed phase

The precipitate of the centrifuged solution was collected by filtration, dried with a vacuum dryer, and used as the measurement sample of the dispersed phase. The obtained sample was swollen in heavy chloroform, and the structural monomer unit was calculated | required using FT-NMR (FX-90Q type by Nippon Electronics Co., Ltd.).

Mass ratio of the composition monomer unit of the styrene- (meth) acrylic acid ester type copolymer calculated | required by the measurement of said (5) (The ratio of a styrene monomer unit is a, and the ratio of a (meth) acrylic acid ester monomer unit is b. , The total amount of the constituent monomer units is 100, and the mass ratio of the constituent monomer units of the dispersed phase sample obtained here (the ratio of the butadiene monomer units c, the ratio of the styrene monomer units d, the (meth) acrylic acid ester monomer units The ratio is e. However, the amount of rubbery elastomer and the graft monomer amount were determined according to the following formulas (5) and (6) from the total amount of the constituent monomer units: 100).

Moreover, although the structural monomer unit was calculated | required the sample of the precipitate (dispersed phase) pretreated in said (1) using FT-NMR, all were consistent with the structural monomer unit obtained above.

Although the examples relating to the thermoplastic resin composition of the present invention were all excellent in molding processability in thin molding, impact resistance and transparency of the thin molded article, in the comparative example relating to the thermoplastic resin composition not meeting the conditions of the present invention, the thin It was inferior in the physical properties of any one of molding processability in molding, impact resistance, and transparency of a thin molded article.

According to the present invention, it is possible to provide a thermoplastic resin composition having excellent transparency and exhibiting excellent impact resistance and molding processability even in a thin molded article.

Claims (8)

(I) Styrene- (meth) which is a copolymer of 20 to 70 mass% of styrene monomer units, 30 to 80 mass% of (meth) acrylic acid ester monomer units and 0 to 10 mass% of vinyl monomer units copolymerizable with these monomers. 60-80 mass% of continuous phases of an acrylic acid ester type copolymer, (II) 20-70 mass% of a styrene-type monomeric unit, and (meth) acrylic-ester type monomeric unit 30-80 mass parts of rubbery elastomers which are a polybutadiene, a styrene-butadiene copolymer, or a polybutadiene and a styrene-butadiene copolymer Styrene- (meth) acrylic acid ester copolymer 20-70 mass parts which is a copolymer of 0-10 mass% of vinyl-type monomeric units copolymerizable with these monomers, 40-20 mass% of the dispersed phase of the graft copolymer grafted As a rubber-modified styrene resin composition containing The volume average particle diameter of a dispersed phase is 0.3-0.6 micrometer, X of Formula (1) calculated | required from the weight average molecular weight (Mw) of the continuous phase and its structural monomeric unit exists in the range of Formula (2), and this resin composition 100 mass The thermoplastic resin composition containing 0.005-0.05 mass parts of organic polysiloxane with respect to a part.

120000 ≤X ≤160000 (2) The rubber-modified styrene-based resin composition according to claim 1, wherein the rubber-modified styrene resin composition comprises 60 to 70 mass% of the continuous phase of the (I) styrene- (meth) acrylic acid ester copolymer and 40 to 30 mass of the dispersed phase of the (II) graft copolymer. A thermoplastic resin composition containing%. The thermoplastic resin composition of Claim 1 or 2 containing 0.1-2.5 mass parts of ester type lubricants with respect to 100 mass parts of rubber modified styrene resin compositions. The thermoplastic resin composition according to claim 3, wherein the ester lubricant is cured castor oil. The thermoplastic resin composition according to claim 1 or 2, wherein the organic polysiloxane is polydimethylsiloxane. delete delete delete