JP2003002931A - Polyvinyl resin composition and vacuum fabricated product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition without occurring foreign materials in its extruded product showing a good appearance, and capable of obtaining a fabricated product having an uniform section on vacuum-fabrication the extruded sheet, and a vacuum-fabricated product having an uniform uneven section and excellent in a appearance. SOLUTION: This resin composition consists of (A) a rubber-reinforced polyvinyl resin obtained by polymerizing an aromatic vinyl compound, a vinyl cyanide compound and if necessary other vinyl compound copolymerizable with at least either one of them in the presence of a rubbery polymer, and satisfies that its acetone soluble fraction contains 0.5-10 wt.% component having >=1,000,000 molecular weight measured by a GPC, based on the total of the soluble fraction, and has <=200,000 weight-average molecular weight(Mw) measured by the GPC and >=3 (Mw/Mn) ratio of the weight-average molecular weight(Mw) to the number average-molecular weight (Wn).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl resin composition containing a rubber-reinforced vinyl resin and a vacuum-formed product of a sheet made of this resin composition. More specifically, the present invention relates to a vinyl-based resin composition capable of producing a molded product such as a sheet having less appearance of hard spots and having an excellent appearance by an extrusion molding method, and having no uneven thickness even when the sheet is vacuum-molded.

Generally, in order to reduce uneven thickness (thickness unevenness) of an ABS resin sheet obtained by extrusion molding and improve vacuum moldability, the ABS resin must contain a high molecular weight component. However, if the amount of the high molecular weight component is too large, the fluidity at the time of melting is lowered, and when the sheet is molded, spots called hard spots (HS) are generated on the appearance of the sheet. In fact, the above method for improving good vacuum forming property is disclosed in JP-A-7-316390 and JP-A-10-10187.
Although proposed in Japanese Patent Publication No. 2), neither vacuum formability and surface appearance are sufficiently compatible with each other.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to obtain a molded product which does not have a so-called hard spot when extrusion molding such as sheet molding or blow molding is performed. Provides a resin composition having a good appearance, a vacuum formed product having good vacuum formability, small uneven thickness, and excellent appearance when the formed sheet is further vacuum formed. To do. Another object of the present invention is to provide a vacuum-molded product obtained from a sheet of a resin composition having excellent properties described above, having a small uneven thickness and an excellent appearance.

[0004]

According to the present invention, (i)
A rubber-reinforced vinyl resin (A) obtained by polymerizing an aromatic vinyl compound, a vinyl cyanide compound and, if necessary, another vinyl compound copolymerizable with at least one of them in the presence of a rubber-like polymer. (Ii) the acetone-soluble component in the composition is a gel permeation chromatography (G).
PC) contains a component having a polystyrene-equivalent molecular weight (hereinafter, simply referred to as “molecular weight”) of 1,000,000 or more in an amount of 0.5 to 10% by weight based on the total amount of the acetone-soluble component, and the weight of the acetone-soluble component by GPC. The average molecular weight (Mw) is 200,000 or less, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the acetone-soluble component by GPC is 3 or more. A vinyl-based resin composition is provided.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The vinyl resin composition of the present invention, as described above,
(I) an aromatic vinyl compound in the presence of a rubbery polymer,
Rubber-reinforced vinyl obtained by polymerizing a vinyl cyanide compound and, if necessary, at least one of these other vinyl-based compounds (hereinafter sometimes referred to as "other copolymerizable vinyl-based compounds"). A system resin (A) (hereinafter sometimes referred to as "component (A)") is contained as an essential component. Component (A) is usually 5 to 70% by weight of a rubber-like polymer, and an aromatic vinyl compound, a vinyl cyanide compound and other copolymerizable vinyl-based compounds polymerized in the presence of the rubber-like polymer. Ingredients 95-30
It is preferable to be composed of 100% by weight (here, the total of both is 100% by weight).

Aromatic vinyl compounds, vinyl cyanide compounds and other copolymerizable vinyl compounds are polymerized or copolymerized (hereinafter sometimes referred to as "(co) polymerization") and grafted to a rubber-like polymer. In addition to being polymerized to form a graft polymer, it does not graft in the (co) polymerized state and coexists with a rubbery polymer as a free (co) polymer.
In addition, the component (A) is a monomer component in the absence of a rubbery polymer, that is, an aromatic vinyl compound, a vinyl cyanide compound and, if necessary, other copolymerizable vinyl compounds. It may be in the form of a so-called graft-blend type rubber-reinforced vinyl-based resin to which a copolymerized copolymer (hereinafter sometimes referred to as “diluting resin”) is appropriately added.

The rubber-like polymer used for preparing the component (A) includes natural rubber, polybutadiene, polyisoprene, polychloroprene, styrene-butadiene copolymer (styrene content is preferably 5 to 60% by weight), styrene. -Isoprene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer,
Styrene-isoprene block copolymer, ethylene-propylene- (non-conjugated diene) copolymer, ethylene-butene-1- (non-conjugated diene) copolymer, isobutylene-isoprene copolymer, styrene-isoprene-styrene block copolymer In addition to polymers and hydrogenated diene (block, random) polymers such as SEBS, acrylic rubber and the like can be mentioned. Among them, preferred is polybutadiene,
Examples thereof include styrene-butadiene copolymer, ethylene-propylene- (non-conjugated diene) copolymer, acrylic rubber and the like. The rubbery polymer can be used alone or in combination of two or more kinds.

The content of the rubber-like polymer in the component (A) is
It is usually in the range of 5 to 70% by weight. If it is less than 5% by weight, the mechanical properties originally possessed by the component (A), particularly impact resistance, are not sufficient, while if it exceeds 70% by weight, the production of the component (A) becomes difficult. A more preferable range of the content of the rubber-like polymer is 10 to 65% by weight, and further preferably 10 to 60% by weight.

In preparing the component (A), an aromatic vinyl compound and a vinyl cyanide compound are used as essential monomers as monomers which are polymerized in the presence of the rubber-like polymer, and further required. Other copolymerizable vinyl compounds are used accordingly. Examples of the aromatic vinyl compound include styrene, t-butylstyrene, α
-Methylstyrene, p-methylstyrene, chlorostyrene, bromostyrene and the like. Particularly preferred are styrene and α-methylstyrene. These aromatic vinyl compounds may be used alone or in combination of two or more. Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Of these, acrylonitrile is preferable. These vinyl cyanide compounds can be used alone or in combination of two or more kinds.

Other copolymerizable vinyl compounds include (meth) acrylic acid esters, maleimide compounds, unsaturated acids, acid anhydride group-containing unsaturated compounds, epoxy group-containing unsaturated compounds, and hydroxyl group-containing unsaturated compounds. Examples include saturated compounds.

The above (meth) acrylic acid ester is preferably an alkyl (meth) acrylate, for example, alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate; Examples thereof include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. Preferred are methyl methacrylate, butyl acrylate, and butyl methacrylate.

The maleimide compounds include maleimide, N-methylmaleimide, N-butylmaleimide,
Examples thereof include N- (p-methylphenyl) maleimide, N-phenylmaleimide, and N-cyclohexylmaleimide, with N-phenylmaleimide and N-cyclohexylmaleimide being preferred. Examples of the unsaturated acid include acrylic acid and methacrylic acid. Examples of the acid anhydride group-containing unsaturated compound include maleic anhydride, itaconic anhydride, citraconic anhydride and the like, and maleic anhydride is preferable. Examples of the epoxy group-containing unsaturated compound include glycidyl methacrylate and allyl glycidyl ether, and glycidyl methacrylate is preferable.

As the above-mentioned unsaturated compound containing a hydroxyl group, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, 3 -Hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and the like can be mentioned. It is preferably 2-hydroxyethyl methacrylate. The above-mentioned other copolymerizable vinyl compounds can be used alone or in combination of two or more kinds. Among these, (meth) acrylic acid esters, maleimide compounds and acid anhydride group-containing unsaturated compounds are preferable. Among the monomers to be grafted on the rubber-like polymer, particularly preferable combinations include styrene and acrylonitrile; styrene, acrylonitrile and methyl methacrylate.

In preparing the component (A), the aromatic vinyl compound, which is an essential monomer, preferably accounts for 50 to 90% by weight of the total amount of the monomers used, more preferably 60. ~ 80% by weight. Further, the vinyl cyanide compound, which is also an essential monomer, preferably accounts for 10 to 50% by weight, and more preferably 20 to 40% by weight, in the total amount of the monomers used.

The above-mentioned component (A) is a conventionally known polymerization method, that is, an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a block polymerization method, an emulsion-suspension polymerization method, a block-one suspension weight method. It can be produced by a conventional method, an emulsion-bulk polymerization method, or the like. A preferred production method is an emulsion polymerization method. At that time, a polymerization initiator, a chain transfer agent, an emulsifier, a solvent, and other additives can be appropriately used. Examples of the polymerization initiator include radical polymerization initiators, specifically, water-soluble initiators such as persulfates, organic hydroperoxides,
Examples thereof include organic peroxides, azo compounds, and redox type initiators in which an oxidizing agent and a reducing agent are combined.
The amount of these radical polymerization initiators used is usually 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the monomer component used.

Examples of the emulsifier include anionic emulsifiers and nonionic emulsifiers that can be used in ordinary emulsion polymerization methods. These emulsifiers may be one kind or a mixture of two or more kinds. As the emulsifier, it is preferable to use an emulsifier having a (low) critical micelle concentration. here,
The critical micelle concentration is preferably (30) mmol / l or less, more preferably (15) mmol.
/ L or less. By using such a low critical micelle concentration, an emulsion system can be formed with a small amount of emulsifier. The amount of emulsifier used is the same as that of Monomer 1 above.
It is usually selected in the range of 0.5 to 5 parts by weight with respect to 00 parts by weight. As the chain transfer agent, octyl mercaptan,
Examples thereof include mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexyl mercaptan and n-hexadecyl mercaptan, hydrocarbon salts such as carbon tetrachloride, terpenes, acrolein and α-methylstyrene dimer. These chain transfer agents may be one kind or a mixture of two or more kinds. The amount of chain transfer agent used is 100 parts by weight of the total amount of monomers,
Usually, it is selected in the range of 0 to 1 part by weight.

When the component (A) is produced by the emulsion polymerization method, various electrolytes, pH adjusters and the like may be used in combination with the radical heavy initiator, the emulsifier, the chain transfer agent and the like, if necessary. it can. With respect to 100 parts by weight of the total amount of monomers, usually 100 to 500 parts by weight of water and the above radical polymerization initiator, emulsifier, chain transfer agent, etc. are used within the above range, and the polymerization temperature is 40 to 100 ° C. Preferably 50-9
Graft polymerization is carried out at 0 ° C. for 1 to 10 hours. After the completion of the graft polymerization, it is purified by coagulating by a usual method, washing the resulting powder with water, and then drying. Examples of the coagulant include magnesium sulfate, sulfuric acid, sodium chloride, calcium chloride and the like. The component (A) thus produced preferably has a graft ratio of 10 to 200%. When the graft ratio is less than 10%, the mechanical strength and solvent resistance originally possessed by the component (A) are impaired, while on the other hand, 200
If it exceeds%, it takes a long time to uniformly disperse the vinyl resin composition when it is obtained, and the moldability is impaired, which is not preferable. The preferred graft ratio is
20 to 180%, more preferably 30 to 80%
Is. The graft ratio of the component (A) can be easily adjusted by changing the type and amount of the polymerization initiator, chain transfer agent, emulsifier, solvent and the like used during the polymerization of the component (A) and the polymerization temperature. .

Component (A) may be blended with a diluting resin, as previously described, which diluting resin is in the absence of a rubbery polymer, the monomeric component, namely the fragrance. It can be produced by copolymerizing a group vinyl compound, a vinyl cyanide compound and, if necessary, other copolymerizable vinyl compound.

As the aromatic vinyl compound, vinyl cyanide compound and other copolymerizable vinyl compounds used in the production of the diluting resin, the same compounds as described above can be used. The diluent resin is preferably a copolymer of an aromatic vinyl compound and a vinyl cyanide compound, and in this case, preferred aromatic vinyl compounds are styrene and α
-Methylstyrene, the preferred vinyl cyanide compound is acrylonitrile, and the combination of styrene and acrylonitrile is particularly preferred. At this time, the usage ratio of the aromatic vinyl compound and the vinyl cyanide compound is the weight ratio of the aromatic vinyl compound and the vinyl cyanide compound (aromatic vinyl compound / vinyl cyanide compound) in view of the balance of various physical properties and processability. Therefore, it is preferably 95/5 to 50/50, and more preferably 75/25 to 65/3.
It is 5. The use ratio of the other copolymerizable vinyl-based monomer is preferably 0 to 30% by weight of the total amount of all monomers,
More preferably, it is 0 to 20% by weight.

From the viewpoint of adapting the resin composition of the present invention to extrusion molding, the diluent resin preferably has a melt flow rate (MFR) in the range of 5 to 50 g / 10 min, and preferably 10 to 40 g / 10 min. Those in the range of are more preferable. The diluting resin can be produced by substantially the same method as the above-mentioned method for producing the graft polymer, except that the rubbery polymer is not used.

The vinyl resin composition of the present invention contains the above component (A) and, if necessary, the above diluting resin, and as a result, the acetone-soluble component has the following molecular weight characteristics. : (Ii-1) A component having a molecular weight of 1,000,000 or more as determined by gel permeation chromatography (GPC) is added in an amount of 0.5 to 10% by weight based on the whole acetone-soluble component,
The content is preferably 0.7 to 5% by weight, (ii-2) the weight average molecular weight (Mw) by GPC is 200,000 or less, preferably 100,000 to 200,000, and (ii-3) the weight average molecular weight by GPC. Ratio (Mw /) of (Mw) and number average molecular weight (Mn)
Mn) is 3 or more, preferably 3.2 or more, and the upper limit is preferably 10, and particularly preferably 7.

Here, the acetone-soluble matter means a soluble matter when the vinyl resin composition is extracted with acetone at 25 ° C., and more detailed extraction conditions are described in the section of Examples. In addition, the weight average molecular weight (Mw) and the number average molecular weight (M
n) is a gel permeation chromatography (GP) using tetrahydrofuran (THF) as a solvent.
It means a value measured by the method C) and calibrated with a polystyrene standard molecular weight, and more detailed measurement conditions are described in the section of Examples. The molecular weight characteristics are obtained by changing the type and amount of the polymerization initiator, chain transfer agent, emulsifier, solvent, etc. used during the polymerization of the component (A), the polymerization temperature, or the type and blending amount of the diluting resin. It can be easily adjusted by changing.

When the amount of the component having a molecular weight of 1,000,000 or more in the acetone-soluble component is too small, the elongational viscosity at high shear of the vinyl resin composition of the present invention is lowered, so that the vinyl resin composition is used as a sheet, When a molded product is manufactured from this sheet by a vacuum molding method, the object of the present invention of making uneven thickness less likely to occur is not achieved. On the other hand, if the amount is too large, the moldability of the vinyl resin composition is deteriorated and the appearance of the molded product is deteriorated. If the weight average molecular weight (Mw) of the acetone-soluble component exceeds 200,000, moldability will be impaired. Mw / of acetone soluble matter
If Mn is too small, the effect of improving the uneven thickness during vacuum forming is not observed, and the appearance deteriorates.

The content of the rubber-like polymer in the total amount of the above component (A) and the optional diluting resin in the vinyl resin composition of the present invention is preferably 5 to 30% by weight, particularly preferably It is preferably 10 to 25% by weight. If the content of the rubber-like polymer is too small, the mechanical properties of the vinyl-based resin composition, particularly impact resistance will be insufficient, and if it is too large, the extrusion moldability of the vinyl-based resin composition will deteriorate.

The melt flow rate (MFR) of the vinyl resin composition of the present invention is preferably 2 to 12 g / 10 min, more preferably 3 to 7 g / 10 min.
If the MFR is too small, the moldability is poor and the appearance tends to be poor. If the MFR is too large, the elongation viscosity property is poor and uneven thickness is likely to occur during vacuum molding. MFR is selected by selecting the type and amount of the rubber-like polymer, changing the type and amount of the polymerization initiator, chain transfer agent, emulsifier, solvent and the like used in the polymerization of the component (A), the polymerization temperature, or the like, or It can be easily adjusted by changing the type and blending amount of the above-mentioned diluent resin.

The vinyl resin composition of the present invention contains a heat stabilizer, an antioxidant, a weather resistance agent, a light resistance agent, a plasticizer, a lubricant, a coloring agent, and a foaming agent as long as the object of the present invention is not impaired. ,
Various resin additives such as flame retardants, flame retardant aids, antibacterial agents, antifungal agents, antirust agents, silicone oils, coupling agents, inorganic fillers, and metal powders can be added.

Since the acetone-soluble component of the vinyl resin composition of the present invention satisfies certain molecular weight characteristics, when it is formed into a sheet by extrusion molding, hard spots called hard spots are unlikely to occur. In addition, this sheet is excellent in vacuum formability and has a small uneven thickness when a molded product is manufactured by a vacuum forming method.For example, even in a deep-drawn molded product such as an inner box for an electric refrigerator, uneven thickness occurs. It is difficult and suitable for producing molded products such as inner boxes and door liners for electric refrigerators. The vinyl resin composition of the present invention is also suitable for blow molding.

[0028]

EXAMPLES The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to the following examples. In the following description, “parts” and “%” are “parts by weight” and “% by weight”, respectively, unless otherwise specified.

In the examples described below, various measurement and evaluation items were according to the following methods. (A) Acetone-soluble component A certain amount (1.0 g) of the vinyl resin composition was added to acetone (30 ml), and the mixture was shaken at 25 ° C. for 2 hours on a shaker to transform the acetone-soluble component into acetone. After dissolving, use a centrifuge to remove the acetone solution at 23.0%.
Centrifugation is carried out for 30 minutes at a rotation speed of 00 rpm, the filtrate is collected, acetone is removed from the filtrate and dried to obtain an acetone-soluble component. (B) Intrinsic Viscosity [η] The polymer was completely dissolved in dimethylformamide to prepare 5 points of solution having different concentrations, and 3 were used with an Ubbelohde viscometer.
The intrinsic viscosity [η] was calculated from the result of measuring the reducing concentration at each concentration of 0 ° C.

(C) Grafting rate (%) A certain amount (x) of the component (A) was added to acetone to obtain 25
Shake for 2 hours on a shaker at ℃ to dissolve the free copolymer, and centrifuge this solution for 23.0
After centrifugation at a rotation speed of 00 rpm for 30 minutes to obtain an insoluble matter, it was dried at 80 ° C. for 8 hours using a vacuum dryer,
The insoluble content (y) was obtained, and the graft ratio (%) was calculated from the following formula. Graft ratio (%) = {(y−x × p) / (x × p)} × 1
00 p: rubber-like polymer fraction in component (A)

(D) Weight average molecular weight (Mw), number average molecular weight (Mn) and Mw / Mn For the acetone-soluble matter obtained according to the above (a),
It measured on the following conditions using the gel permeation chromatography (GPC) apparatus. Apparatus: Tosoh Corp. HLC-8020 Column: TOSO TSK-GEL G6000H + G
Two 500H Series temperature: 40 ° C. Detector: Differential refractometer Solvent: Tetrahydrofuran (THF), Concentration: 0.1% Injection amount; 50 μL Calibration curve: Tosoh Corp., standard polystyrene (PS) compliant (molecular weight Is PS conversion value)

(E) Melt flow rate (MFR) (unit: g / 10 min) According to ISO 1133, temperature 220 ° C., load 10 k
It was measured under the condition of g. (F) Uneven thickness (by vacuum forming method) A sheet having a thickness of 2 mm is produced from a resin composition by an extrusion forming method, and a vacuum forming machine (FC-4APA manufactured by Asano Laboratory, plug assist type) is produced from this sheet. Using a sheet heating time of 60 seconds, opening diameter 300mm, bottom diameter 1
A molded product having a bucket shape with a depth of 50 mm and a depth of 250 mm and having a width of 6 mm reaching from the opening to the bottom and protruding outward was provided to oppose the wall surface. With respect to the obtained molded product, the part farthest from the rib was vertically cut from the opening to the bottom, and the measured minimum wall thickness on the cut surface was shown. The larger the measured value is, the less preferable the uneven thickness is. The evaluation criteria are shown below. ◯: Minimum wall thickness measured value 0.2 mm or more ×: Minimum wall thickness measured value less than 0.2 mm

(G) Measurement of Hard Spot (HS) A sheet having a thickness of 2 mm was produced from the resin composition by an extrusion molding method, and the sheet was irradiated with light to detect foreign matter (hard spot) with a CCD camera. The following numerical value which is proportional to the size of the hard spot is given, and the predetermined area (5 x 30c
The sum of the numerical values in m) is shown as the HS value. HS major axis is 0.94 mm or more: numerical value 0.60 HS major axis is 0.50 or more and less than 0.94 mm: numerical value 0.12 HS major axis is 0.10 or more and less than 0.50 mm: numerical value 0.06

(1) Preparation of rubber-reinforced vinyl resin (A-1) (1-1) Production of rubbery polymer 5 liters equipped with reflux condenser, stirring blade, auxiliary agent adding device, thermometer, etc. Prepare a stainless steel autoclave of, and in this autoclave, 150 parts of deionized water,
4.0 parts of higher fatty acid soap (sodium salt of fatty acid having 18 carbon atoms as a main component) and 0.075 part of sodium hydroxide were charged, and after nitrogen substitution, the internal temperature was raised to 68 ° C. with stirring. In this autoclave, 90 parts of 1,3-butadiene (BD), 10 parts of styrene (St), and t-
After charging 20% of a monomer mixture consisting of 0.3 part of dodecyl mercaptan (TDM), 0.135 part of potassium persulfate was added. After a few minutes, heat was generated and the initiation of polymerization was confirmed. One hour after the addition of potassium persulfate, the continuous addition of the remaining 80% -equivalent amount of the monomer mixture was started, and the addition was completed at 6 hours.
After the continuous addition was completed, the internal temperature was raised to 80 ° C., and the reaction was continued at this temperature for another hour to complete the polymerization reaction. The obtained rubber-like polymer latex had a solid content concentration of 39.5.
%, The average particle size was 0.1 μm, and the gel content was 95%.

(1-2) Rubber-reinforced vinyl resin (A-
Production of 1) Acetic anhydride was added to the rubber-like polymer latex produced in (1-1) above in a reaction vessel having a capacity of 5 liters equipped with a reflux condenser, a stirring blade, an auxiliary addition device, a thermometer and the like. Then, 100 parts as a solid content and 200 parts of deionized water (including water in the latex) were charged with the particles having an average particle size enlarged to 0.25 μm, and the internal temperature was raised. Inner temperature is 65
From the time when the temperature reached ℃, a monomer mixture consisting of styrene 68 parts, acrylonitrile 32 parts and terpinolene (chain transfer agent) 0.25 parts, deionized water 41 parts, disproportionated potassium rosinate 1.8 parts , Potassium persulfate 0.32
Part, and an aqueous solution in which 0.45 parts of potassium hydroxide were dissolved were continuously added to the reaction vessel over 3 hours and 30 minutes.

The internal temperature was gradually raised during the continuous addition, and 2 hours and 30 minutes passed after the start of the continuous addition, and when the internal temperature reached 80 ° C., 0.08 part of potassium persulfate was added, and 0.45 parts of homogenized potassium rosinate were added all at once. After 3 hours from the start of continuous addition, the internal temperature was adjusted to 85 ° C., the reaction was continued for 4 hours from the start of continuous addition, and the reaction vessel was cooled to complete the graft reaction. After adding 2.5 parts of an antioxidant to the obtained graft polymer latex, 9
The mixture was added to an aqueous magnesium sulfate solution aged at 5 ° C with stirring to coagulate, and the coagulated product was washed with water and dried to obtain a white powdery rubber-reinforced vinyl resin (A-1). The content of the styrene-butadiene copolymer rubber in the obtained rubber-reinforced vinyl resin (A-1) was 50%, and the graft ratio was 60%.

(2) Preparation of rubber-reinforced vinyl resin (A-2) In a reaction vessel having a volume of 5 liters similar to the above (1-2),
Acetic anhydride was added to the rubber-like polymer latex produced in the above (1-1) to increase the average particle diameter to 0.35 μm.
Part (including water in latex) was charged and the internal temperature was raised. From the time when the internal temperature reached 60 ° C, styrene (S
t) A monomer mixture consisting of 70 parts and 30 parts of acrylonitrile (AN) and cumene hydroperoxide 3.2.
Solution, 1.8 parts of disproportionated potassium rosinate and 0.38 parts of potassium hydroxide were continuously added to the reaction vessel over 2 hours and 45 minutes. When the temperature reached 60 ° C., a solution in which 5.2 parts of glucose and 0.065 parts of ferrous sulfate were dissolved was added all at once. Polymerization was carried out at a constant temperature of 70 ° C from the time when the internal temperature reached 70 ° C. Polymerization was continued for 3 hours from the start of continuous addition, and the reaction vessel was cooled to complete the graft reaction. After adding 2.5 parts of an antioxidant to the obtained graft polymer latex, the mixture is added to an aqueous magnesium sulfate solution heated at 95 ° C with stirring to coagulate, and the coagulated product is washed with water and dried to give a white powder. Rubber-reinforced vinyl resin (A
-2) was obtained. The obtained rubber-reinforced vinyl resin (A-
The content of styrene-butadiene copolymer rubber in 2) is 50.
%, And the graft ratio was 50%.

(3) Preparation of rubber-reinforced vinyl resin (A-3) Bulk-suspension polymerization using 14 parts of polybutadiene rubber as a rubber-like polymer, 66 parts of styrene as a monomer and 20 parts of acrylonitrile. Then, a rubber-reinforced vinyl resin (A-3) was obtained. The content of the polybutadiene rubber in the obtained rubber-reinforced vinyl resin (A-3) was 14
%, And the graft ratio was 60%.

(4) Diluting Resins (AS-1 to AS-6) (4-1) Preparation of AS-1 With a capacity of 5 liters equipped with a reflux condenser, a stirring blade, an auxiliary agent adding device, a thermometer and the like. Copolymer in which potassium stearate is used as an emulsifier, potassium persulfate is used as a polymerization initiator, styrene / acrylonitrile is used as a monomer, and a styrene / acrylonitrile copolymerization ratio (weight ratio) is 70/30 in a reaction vessel. Was produced by an emulsion polymerization method. The obtained copolymer has an intrinsic viscosity [η] of 3.7 dl.
/ G.

(4-2) AS-2: AS resin manufactured by General Electric Company, USA, having a styrene / acrylonitrile copolymerization ratio (weight ratio) of 70/30 and an intrinsic viscosity [η] of 5. 4 dl / g copolymer. (4-3) AS-3: AS resin (trade name SAN-C) manufactured by Techno Polymer Co., Ltd., which has styrene / acrylonitrile (weight ratio = 74/26) and a weight average molecular weight of 1
62000, Mw / Mn 3.2, MFR 25g / 1
0 min copolymer. (4-4) AS-4 AS resin manufactured by Techno Polymer Co., Ltd. (trade name: SAN-
F) and styrene / acrylonitrile (weight ratio =
71/29), the weight average molecular weight is 112000, Mw /
Copolymer with Mn of 3.1 and MFR of 60 g / 10 min. (4-5) AS-5 AS resin manufactured by Techno Polymer Co., Ltd. (trade name: SAN-
H) and styrene / acrylonitrile (weight ratio =
70/30), weight average molecular weight 225,000, Mw /
Copolymer with Mn of 3.1 and MFR of 4 g / 10 min. (4-6) AS-6 AS resin manufactured by Techno Polymer Co., Ltd. (trade name: AP35
-100), styrene / acrylonitrile (weight ratio = 66/34), weight average molecular weight 148,000,
A copolymer having an Mw / Mn of 3.1 and an MFR of 28 g / 10 min.

Examples 1 to 5 and Comparative Examples 1 to 3 Melt a rubber-reinforced vinyl resin shown in Table 1 and a diluting resin at a ratio shown in Table 1 in a Banbury mixer,
After kneading to prepare a vinyl resin composition in the form of pellets and thoroughly drying the pellets, the above (a) and (d)
It used for evaluation of- (g). The results are shown in Table 1.

[0042]

[Table 1]

From the results shown in Table 1, the following is clear. Consists of a rubber-reinforced vinyl resin (A) and an AS resin, the amount of components having a molecular weight of 1,000,000 or more in the acetone-soluble matter, the value of the weight-average molecular weight (Mw) of the acetone-soluble matter, and the Mw of the acetone-soluble matter. The value of / Mn is a vinyl resin composition satisfying the range specified in the present invention (Examples 1 to 1).
In the case of 5), a vacuum-formed product having less uneven thickness, excellent vacuum forming properties, and extremely small hard spots and an excellent appearance can be obtained.

On the other hand, the resin composition of Comparative Example 1 in which the component having a molecular weight of 1,000,000 or more does not exist in the acetone-soluble component and which does not satisfy the requirements of the present invention has remarkably uneven thickness and is inferior in vacuum moldability.
Further, although the amount of components having a molecular weight of 1,000,000 or more in the acetone-soluble component increased to 0.4%, the resin composition of Comparative Example 2 which did not satisfy the requirements of the present invention had a slight uneven thickness. Although improved, many hard spots occur and the appearance of molded products is inferior. Although the amount of the component having a molecular weight of 1,000,000 or more in the acetone-soluble matter satisfies 1.0% of the specification of the present invention, the Mw of the acetone-soluble matter exceeds the specification of the present invention.
In the case of Comparative Example 3 which has a high molecular weight of 45,000 and does not satisfy the requirements of the present invention, the rubber-reinforced vinyl resin (A-1) and A
The S resin (AS-5) is not uniformly mixed, and the vacuum moldability is poor to the extent that vacuum molding is impossible.

[0045]

EFFECTS OF THE INVENTION The resin composition of the present invention does not generate hard spots called hard spots in the obtained molded product when subjected to extrusion molding such as sheet molding and blow molding,
It has a good appearance. Further, the sheet molded from the resin composition of the present invention has a good vacuum moldability, has a small uneven thickness, and gives a vacuum molded product having an excellent appearance. Further, the vacuum-formed product of the present invention has a small uneven thickness and is excellent in appearance.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Kurata             1-18-1 Kyobashi, Chuo-ku, Tokyo Techno             Within Polymer Co., Ltd. F term (reference) 4J026 AA06 AA16 AA68 AA69 AA71                       AC02 AC10 AC11 AC16 AC32                       BA05 BA31 BB03 DA04 DA12                       DA13 DA16 DB04 DB12 DB13                       DB16 GA01 GA03

Claims (3)

[Claims] 1. Obtained by polymerizing (i) an aromatic vinyl compound, a vinyl cyanide compound and, if necessary, another vinyl compound copolymerizable with at least one of them in the presence of a rubbery polymer. A vinyl-based resin composition containing a rubber-reinforced vinyl-based resin (A), comprising: (ii)
The acetone-soluble component in the composition contains 0.5 to 10% by weight based on the total amount of the acetone-soluble component of a component having a polystyrene reduced molecular weight of 1,000,000 or more by gel permeation chromatography (GPC). The weight average molecular weight (Mw) of the acetone-soluble component by GPC is 200,000 or less, and the ratio (Mw / Mw) of the weight-average molecular weight (Mw) of the acetone-soluble component by GPC and the number average molecular weight (Mn).
Mn) is 3 or more, The vinyl resin composition characterized by the above-mentioned. 2. A rubber-reinforced vinyl resin (A) comprising 5 to 70% by weight of a rubber-like polymer, aromatic vinyl compound, vinyl cyanide compound and other copolymerizable vinyl compound components 95 to 30. % By weight (where the sum of the two is 1
The vinyl-based resin composition according to claim 1, wherein the vinyl-based resin composition is 100% by weight. 3. The melt flow rate at 220 ° C. under a load of 10 kg is 2 to 12 g / 10 min.
Alternatively, the vinyl resin composition according to item 2.