JPH0841286A - Abs resin composition having excellent fluorocarbon resistance and inner box for refrigerator comprising the same composition - Google Patents

Abstract

PURPOSE:To obtain a composition suitable for producing a refrigerator for a substitute fluorocarbon (HCFC-141b), having excellent fluorocarbon resistance and appearance (gloss). CONSTITUTION:This ABS resin composition comprises a graft polymer (X) obtained by polymerizing 80-20wt.% of monomers of 20-40wt.% of a vinyl cyanide compound (ACN) and 80-60wt.% of an aromatic vinyl compound (STY) in the presence of 20-80wt.% of a rubber-like polymer having 0.4-0.6mu particle diameter, an aggregated graft polymer (Y) obtained by polymerizing 60-20wt.% of monomers of 30-45wt.% of ACN and 70-55wt.% of STY in the presence of 40-80 wt.% of rubber having 0.05-0.2mu particle diameter to provide a graft polymer (y) of a small particle diameter having 10-40% graft ratio and aggregating the graft polymer into a clustered state having 0.8-2.0mu weight-average particle diameter and a copolymer (Z) obtained by polymerizing 35-45wt.% of ACN with 65-55wt.% of STY, having 0.6-0.9 intrinsic viscosity. The ABS resin composition has the weight ratio of the rubber in the graft polymer (X) to that in the graft polymer (Y) of 1:(1-4) and comprises 15-25wt.% of total amounts of the rubbers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a BS resin composition and a refrigerator inner box made of such a composition. Particularly, the present invention relates to an ABS resin composition suitable for producing a refrigerator inner box by a polyurethane foaming method using a substitute for CFC-11 as a foaming agent, and the refrigerator inner box.

[0002]

2. Description of the Related Art Conventionally, impact-resistant polystyrene (HIPS) and ABS resin (acrylonitrile-butadiene rubber-styrene) are used for the inner box of a heat insulating box for keeping cold in refrigerators, freezers, ice makers, and the like. , Trichloromonofluoromethane (CFC-1), which is CFC as an insulating material
A polyurethane foam using 1) as a foaming agent is used. In particular, ABS resin has excellent mechanical properties and workability, as well as adhesiveness to urethane foam, heat generation during contact with CFC-11 and heat generated during urethane foaming, and stress characteristics due to cooling It is most suitable as a material for the inner box.

However, in recent years, production and use of ozone depleting substances such as CFC-11 have been regulated,
New blowing agents are being investigated. As an alternative substance of CFC-11, 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123), 1,1-dichloro-1
-Fluoroethane (HCFC-141b) and the like have been proposed, but these alternative substances are more polar than CFC-11, and conventional ABS resin easily cracks or breaks due to contact with the alternative substance.

Although a method of increasing the rubber component and acrylonitrile component constituting the ABS resin has already been proposed, the increase of the rubber component (Japanese Patent Laid-Open No. 4-132712) reduces the rigidity of the resin and also increases the acrylonitrile component. (JP-A-4-170409, 5-17540, 5-1
7541) sacrifices the excellent mechanical strength and thermal stability inherent in ABS resin. ABS resin prepared by introducing methacrylic acid ester as a copolymer component (JP-A-4-1267).
56) has also been proposed, but the CFC resistance is not sufficient, and the excellent mechanical strength inherent to the ABS resin is sacrificed as in the case of increasing the acrylonitrile component.

A method of blending an ABS resin with another polymer has also been proposed. For example, blending of a thermoplastic polyester elastomer (JP-A-4-132762, 4-1).
70451), A obtained by increasing the acrylonitrile component
Blending of higher fatty acid triglyceride into BS resin (JP-A-4-154858), combined use of acrylic rubber modified graft with increased acrylonitrile component and butadiene rubber modified graft (JP-A-4-170460), ethylene-propylene rubber modified Combined use of graft and butadiene rubber modified graft (JP-A-4-170461), combined use of ethylene-propylene rubber modified graft and acrylic rubber modified graft (JP-A-4-170462), blending of polyester (JP-A-5-17658). And so on. Although these also improve the chlorofluorocarbon resistance, they cannot be said to be sufficient.

Further, it has been proposed to use an aggregate as a rubber or a graft component constituting the ABS resin. For example, a method of using an agglomerated rubber as a rubber component (Japanese Patent Publication No. Sho 52-30034), a method of grafting a small amount of a compound on a rubber component (low graft ratio), and then agglomerating and expanding the graft polymer (Japanese Patent Publication No. 2737
8) A method in which a small amount of a compound is grafted to a rubber component, and then agglomerated and enlarged to form a cluster, and then a larger amount of the compound is grafted (JP-A-5-25227).
And so on. These also improve the CFC resistance, but it cannot be said to be sufficient.

[0007] Therefore, it is more resistant to CFCs (e.g., easily cracks or breaks when contacted with an alternative substance) without sacrificing the excellent mechanical strength, thermal stability, processability, etc., which are the characteristics of ABS resin. It does not occur.) And the development of a material having excellent surface gloss has been desired.

[Problems to be Solved by the Invention]

The present invention relates to HCFC-123 and HCFC-
It is intended to provide an ABS resin composition suitable for manufacturing an inner box of a heat insulating box using an alternative CFC such as 141b and a refrigerator inner box thereof.

[Means for solving problems]

The inventors of the present invention have found that a graft polymer using a medium particle diameter rubber, a large particle diameter graft polymer obtained by aggregating a graft polymer using a small particle diameter rubber into a tuft, and a copolymer. The composition consisting of and a refrigerator inner box composed of such a composition have excellent mechanical strength, heat stability, processability, and appearance (gloss), which are the features of ABS resin,
Further, they have found that the material is extremely excellent in chlorofluorocarbon resistance and arrived at the present invention.

That is, according to the present invention, the weight average particle diameter is 0.
Polymerize 20 to 40% by weight of vinyl cyanide compound and 80 to 20% by weight of monomer of aromatic vinyl compound 80 to 60% by weight in the presence of 20 to 80% by weight of rubbery polymer of 4 to 0.6μ. 30% to 45% by weight of a vinyl cyanide compound and 70% of an aromatic vinyl compound in the presence of 40% to 80% by weight of a rubbery polymer having a weight average particle diameter of 0.05 to 0.2 µ. Aggregated graft polymer obtained by polymerizing 55% by weight of 60 to 20% by weight of a monomer, and a small particle diameter graft polymer (y) is aggregated into a tuft having a weight average particle diameter of 0.8 to 2.0 μ. (Y), vinyl cyanide compound 35-
A rubbery polymer of a graft polymer (X), which is composed of a copolymer (Z) having an intrinsic viscosity of 0.6 to 0.9 formed by polymerizing 45% by weight of an aromatic vinyl compound and 65 to 55% by weight. ABS resin composition having excellent flon resistance and gloss, wherein the weight ratio of the rubbery polymer of the agglomerated graft polymer (Y) is 1 to 1 to 4, and the total amount of the rubbery polymer is 15 to 25% by weight. And a refrigerator inner box made of such a composition, which is excellent in CFC resistance and gloss. The present invention will be described in detail below.

The rubbery polymer constituting the graft polymers (X) and (Y) is a conjugated diene rubber such as polybutadiene, butadiene-styrene polymer, butadiene-acrylonitrile polymer, ethylene-propylene polymer, ethylene. -Propylene-non-conjugated diene (ethylidene norbornene, dicyclopentadiene, etc.) polymer, ethylene-
Ethylene-α-olefin rubber such as butylene polymer, polyisoprene, polybutyl acrylate, ethylene-vinyl acetate polymer, chlorinated polyethylene, hydrogenated product of butadiene-styrene polymer (SEBS), and the like,
One kind or two or more kinds can be used. Particularly, conjugated diene rubber and ethylene-α olefin rubber are preferable.

The vinyl cyanide compound constituting the graft polymers (X), (Y) and the copolymer (Z) includes acrylonitrile, methacrylonitrile, fumaronitrile and the like, and one or more of them may be used. I can. Acrylonitrile is particularly preferred. Examples of aromatic vinyl compounds include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene, and dichloro. Styrene, bromostyrene, dibromostyrene, vinylnaphthalene, etc. are exemplified, and one kind or two or more kinds can be used. Particularly preferred is styrene.

Within a range not departing from the object of the present invention, a part of the aromatic vinyl compound is methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate. Unsaturated carboxylic acid alkyl ester such as maleimide, methylmaleimide, ethylmaleimide, N-
Substitution with a maleimide compound such as phenylmaleimide or O-chloro-N-phenylmaleimide is also possible.

Graft polymer (X) The graft polymer (X) has a weight average particle diameter of 0.4 to 0.
Graft weight obtained by polymerizing 20 to 40% by weight of a vinyl cyanide compound and 80 to 20% by weight of a monomer of 80 to 60% by weight of an aromatic vinyl compound in the presence of 20 to 80% by weight of a rubbery polymer of 6μ. It is united.

The weight average particle diameter of the rubbery polymer is 0.4 μm.
If it is less than 0.6, the impact resistance is inferior, and if it exceeds 0.6 μ, the CFC resistance cannot be improved. If the rubbery polymer is less than 20% by weight, the impact resistance is poor, and if it exceeds 80% by weight, the rigidity is lowered, which is not preferable. Further, if the vinyl cyanide compound is less than 20% by weight (more than 80% by weight of the aromatic vinyl compound), the CFC resistance is not improved, and if it exceeds 40% by weight (the less than 60% by weight of the aromatic vinyl compound), the thermal stability is improved. Is inferior and is not preferable. From the viewpoint of flon resistance, mechanical strength and thermal stability, vinyl cyanide compound 25 is used in the presence of 40 to 60% by weight of a rubbery polymer having a weight average particle size of 0.4 to 0.5 μm.
A graft polymer obtained by polymerizing 60 to 40 wt% of a monomer of 30 to 30 wt% and an aromatic vinyl compound of 75 to 70 wt% is preferable. The graft ratio showing the amount of vinyl cyanide compound and aromatic vinyl compound bonded on the rubbery polymer is not limited, but from the standpoint of flon resistance, mechanical strength and heat stability, 70% is preferable.

Graft polymer (Y) The graft polymer (Y) has a weight average particle diameter of 0.05 to
Polymerized with 30 to 45% by weight of a vinyl cyanide compound and 60 to 20% by weight of a monomer of 70 to 55% by weight of an aromatic vinyl compound in the presence of 40 to 80% by weight of a rubbery polymer of 0.2μ. It is a graft polymer (Y) formed by aggregating a small particle diameter graft polymer (y) having a graft ratio of 10 to 40% by weight into a tuft having a weight average particle diameter of 0.8 to 2.0 µ.

The weight average particle diameter of the rubbery polymer is 0.05.
If it is less than μ, the CFC resistance is poor, and if it exceeds 0.2 μ, the CFC resistance cannot be improved. If the content of the rubber-like polymer is less than 40% by weight, the graft polymer (y) having a small particle size does not form a tuft and the CFC resistance cannot be improved. If it exceeds 80% by weight, the CFC resistance is deteriorated. When the vinyl cyanide compound is less than 30% by weight (over 70% by weight of the aromatic vinyl compound), the CFC resistance is inferior, and when it exceeds 45% by weight (less than 55% by weight of the aromatic vinyl compound), a small particle diameter graft weight is obtained. The thermal stability of the combined (y) is reduced. The graft ratio showing the amount of vinyl cyanide compound and aromatic vinyl compound bonded on the rubber polymer is 10 to 40% by weight. The graft ratio is determined according to the following equation after separating the soluble portion and the insoluble portion using acetone as a solvent. Graft ratio (%) = [Acetone insoluble part weight−Rubber polymer weight in graft polymer (Y)] ÷ Rubber polymer weight in graft polymer (Y) × 100. When the graft ratio is less than 10% by weight, the CFC resistance and the appearance (gloss) are poor, and when it exceeds 40% by weight, the graft polymer (y) is not tufted and the CFC resistance cannot be improved.
The graft ratio can be adjusted by appropriately changing the polymerization conditions such as the polymerization temperature, the compound addition method, and the composition ratio. Furthermore, examples of the method for producing the graft polymer (y) include known emulsion polymerization method, suspension polymerization method, solution polymerization method, bulk polymerization method, and combinations thereof. In the polymerization, known polymerization aids such as a molecular weight modifier and an initiator can be used.

The small particle diameter graft polymer (y) having the above composition and structure aggregates into tufts during granulation and molding. The aggregated graft polymer has a tufted shape, and a conventionally known graft polymer aggregated in a donut shape cannot obtain excellent flon resistance. The aggregate graft polymer has a weight average particle diameter of 0.8 to 2.0 μ. If it is less than 0.8μ, it is inferior in CFC resistance, and if it exceeds 2.0μ, the appearance (gloss).
Is inferior and is not preferable. From the viewpoint of flon resistance and mechanical strength, 35 to 40% by weight of a vinyl cyanide compound and an aromatic vinyl compound are present in the presence of 50 to 60% by weight of a rubbery polymer having a weight average particle diameter of 0.05 to 0.2 μ. A graft polymer obtained by polymerizing 50 to 40% by weight of a monomer of 65 to 60% by weight and having a small particle size and agglomerated in a tuft having a weight average particle size of 0.8 to 2.0 μ is preferable. . The weight average particle diameter of the aggregate is obtained by measuring the long axis and the short axis of the aggregate from an electron micrograph, and taking the average value as the particle diameter. From the particle diameter of at least 10 particles of the aggregate thus measured, Calculate the average particle size.

Copolymer (Z) The copolymer (Z) used in the present invention means 35 to 45% by weight of a vinyl cyanide compound and 65 to 65 of an aromatic vinyl compound.
It is a copolymer having an intrinsic viscosity of 0.6 to 0.9 obtained by polymerizing 55% by weight. If the amount of the vinyl cyanide compound is less than 35% by weight (exceeding 65% by weight of the aromatic vinyl compound), the CFC resistance cannot be improved, and if it exceeds 45% by weight (less than 55% by weight of the aromatic vinyl compound), the thermal stability is improved. Inferior and not preferable.
In addition, the intrinsic viscosity of the copolymer means that a dimethylformamide solution (concentration of 0.1 to 0.5% by weight) in which the concentration of the copolymer is changed is prepared and each viscosity is measured at 30 ° C. using a viscosity tube. The specific viscosity is determined, and the value at the time of zero concentration is calculated from the relational expression of the specific viscosity and the concentration. Further, if the intrinsic viscosity of the copolymer is less than 0.6, the CFC resistance cannot be improved, and if it exceeds 0.9, the sheet processability is poor, which is not preferable. From the standpoints of CFC resistance, mechanical strength, heat stability, sheet processability, etc. of the composition and the molded product, 35-40% by weight of a vinyl cyanide compound and 65 of an aromatic vinyl compound are used.
A copolymer having an intrinsic viscosity of 0.7 to 0.8 obtained by polymerizing 60 to 60% by weight is particularly preferable. The intrinsic viscosity can be adjusted by appropriately changing the polymerization conditions such as the type and amount of the molecular weight modifier or the initiator, the polymerization temperature, the method of adding the compound, and the composition ratio.

Further, as the method for producing the copolymer (Z), known emulsion polymerization method, suspension polymerization method, solution polymerization method,
Bulk polymerization methods as well as combinations thereof may be mentioned.
In the polymerization, known polymerization aids such as a molecular weight modifier and an initiator can be used.

Composition The ABS resin composition and molded article of the present invention are composed of the above-mentioned graft polymer (X), graft polymer (Y) and copolymer (Z). The weight ratio of the rubber polymer of the graft polymer (X) and the rubber polymer of the graft polymer (Y) is 1 to 1 to 4, and when the ratio is less than 1 (Y
The weight of the rubbery polymer of X is less than the weight of the rubbery polymer of X)
It is inferior in chlorofluorocarbon resistance, and if it exceeds 4 (the weight of the rubbery polymer of Y exceeds 4 times the weight of the rubbery polymer of X), the appearance (gloss) is inferior, which is not preferable. In particular, such a weight ratio is 1: 1.
5-3 is preferable. The rubber-like polymer (the total amount of the rubber-like polymer obtained from the graft polymer X and the graft polymer Y) in the composition is 15 to 25% by weight. If it is less than 15% by weight, impact resistance and CFC resistance are poor,
On the other hand, if it exceeds 25% by weight, the rigidity becomes poor, which is not preferable. From the standpoint of flon resistance and mechanical strength, 20 to 25% by weight is particularly preferable.

The mixing method with the graft polymer (X), the graft polymer (y) and the copolymer (Z) is not particularly limited, and it may be in a water dispersion state (latex) or may be powder, beads, pellets or the like. It can be mixed in the state. Further, the order of mixing is not limited, and examples thereof include a method of collectively mixing three components, a method of mixing two specific components, and then adding and mixing the remaining components. Further, as a melt-kneading method, a known method such as a Banbury mixer, a roll or an extruder can be adopted. At the time of mixing, additives such as an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a dye, a pigment, a plasticizer, a flame retardant, and a release agent can be blended if necessary.

The refrigerator inner box of the present invention may be formed by, for example, sheet-extruding the above ABS resin composition and then forming the inner box by a vacuum forming method, or by directly injection-molding the inner box from the composition. .

The present invention will be specifically described below with reference to examples. The number of parts and% are shown by weight.

Reference Example 1-Rubber polymer for graft polymer X 90 parts butadiene, 10 parts styrene, 0.5 parts sodium oleate, 0.2 parts dodecyl mercaptan, 0.3 parts potassium persulfate, sodium hydroxide 0.1 part and 95 parts of deionized water were charged into a stainless reactor equipped with a stirrer, and polymerized at 60 ° C. for 18 hours and then at 70 ° C. for 15 hours. The weight average particle diameter was 0.45μ.

Reference Example 2 Rubber Polymer for Graft Polymer y 1.5 parts by weight of sodium oleate and 1 part by weight of deionized water
The same operation as in Reference Example 1 was performed except that the amount was changed to 70 parts to obtain a rubbery polymer having a weight average particle diameter of 0.15 μ.

Reference Example 3 Aggregated rubbery polymer Aqueous phosphoric acid solution (5%) was added to the 0.15 μm rubbery polymer latex prepared in Reference Example 2 with stirring, and p
After H3 is added, further sodium hydroxide aqueous solution (25
%) Was added to obtain a rubbery polymer having a weight average particle diameter of 0.80 μ and aggregated in a tuft.

Reference Example 4 Graft Polymer X 100 parts of the 0.45μ rubbery polymer latex (solid content 50%) obtained in Reference Example 1 and 80 parts of deionized water in a polymerization tank equipped with a reflux condenser and dextrin. An aqueous solution in which 0.1 part, 0.1 part of anhydrous sodium pyrophosphate and 0.005 part of ferrous sulfate was dissolved was added, and the gas phase part was replaced with nitrogen.
The temperature was raised to ° C. When the temperature in the bath reached 70 ° C., 14 parts of acrylonitrile, 36 parts of styrene, 0.2 part of t-dodecyl mercaptan, 0.3 part of cumene hydroperoxide, 20 parts of deionized water, and 1.5 parts of potassium oleate. An emulsifier solution with parts dissolved was continuously added over 4 hours. After the continuous addition was completed, the mixture was aged at 70 ° C. for 2 hours to complete the polymerization. The obtained graft polymer latex was salted out with magnesium sulfate, dehydrated and dried to obtain a graft polymer X having a graft ratio of 40%.

Reference Example 5 Graft polymer y 170 parts of 0.15μ rubbery polymer latex (solid content 35.3%) obtained in Reference Example 2 and acrylonitrile 1
4 parts, styrene 26 parts, t-dodecyl mercaptan 0.
Polymerization was carried out by the same procedure as in Reference Example 4 except that 5 parts and 10 parts of deionized water were used to obtain a graft polymer y having a graft ratio of 30%.

Reference Example 6-Graft Polymer 226 parts of 0.15μ rubbery polymer latex (solid content 35.3%) obtained in Reference Example 2, acrylonitrile 7
Parts and styrene, except that the amount of styrene was changed to 13 parts to carry out polymerization in the same manner as in Reference Example 5 to obtain a graft polymer having a graft ratio of 6%.

Reference Example 7-Graft polymer Polymerization was carried out by the same procedure as in Reference Example 5 except that t-dodecyl mercaptan was changed to 0 part to obtain a graft polymer having a graft ratio of 50%.

Reference Example 8 Graft Polymer Polymerization was carried out in the same procedure as in Reference Example 5 except that the agglomerated rubbery polymer obtained in Reference Example 3 was used to obtain a graft polymer having a graft ratio of 30%. .

Reference Example 9 Copolymer Z After replacing the stainless reactor equipped with a stirrer with nitrogen, an initiator aqueous solution prepared by dissolving 0.3 part of potassium sulfate in 100 parts of deionized water was charged and heated to 65 ° C. From that point, a monomer mixture consisting of 65 parts of styrene, 35 parts of acrylonitrile and 0.25 part of t-dodecyl mercaptan, an emulsifier aqueous solution consisting of 20 parts of deionized water and 1.5 parts of sodium oleate were continuously added for 4 hours. Added and polymerized. After the continuous addition was completed, the temperature was raised to 70 ° C. and aging was carried out for 2 hours to complete the reaction. The obtained copolymer latex was salted out with magnesium sulfate, dehydrated and dried to obtain a powdery copolymer Z. Acrylonitrile in the copolymer Z is 33.9%,
The intrinsic viscosity was 0.75.

Reference Example 10 Copolymer A copolymer was obtained by the same procedure as in Reference Example 9 except that 70 parts of styrene, 30 parts of acrylonitrile and 0.22 part of t-dodecyl mercaptan were used. The acrylonitrile content in the obtained copolymer was 28.5% and the intrinsic viscosity was 0.
It was 75.

Reference Example 11 Copolymer A copolymer was obtained by the same procedure as Reference Example 9 except that t-dodecyl mercaptan was changed to 0.5 part. The acrylonitrile content in the obtained copolymer was 33.6%, and the intrinsic viscosity was 0.55.

Examples and Comparative Examples After mixing the graft polymer and the copolymer obtained in Reference Example based on the compounding ratios shown in Tables 1 and 2, at 220 ° C. using a uniaxial extruder having a diameter of 40 mm. Melt kneading was performed to obtain various compositions (pellets). The state of aggregation of the graft polymer was confirmed and the properties of various compositions were evaluated. The results are shown in Table-1
~ 2. In the table, A indicates acrylonitrile and IV indicates the intrinsic viscosity.

How to confirm the aggregation status. A hot press sheet was prepared from the obtained pellets, and the presence or absence of aggregation was determined and the size of the aggregate was calculated from the electron micrograph.

Various characteristics were evaluated as follows. (1) Notched Izod Impact Strength (NI) Using a 3.5 oz injection molding machine, cylinder set temperature 2
According to ASTM D-256 at 20 ° C, a 1/4 inch thick test piece was prepared and measured at 23 ° C. (2) Workability Measure MFR (melt flow rate) under load of 220 ° C. and 10 kg / cm. (3) Thermal stability The sample was allowed to stay in a high-performance flow tester at 260 ° C for 30 minutes, and the degree of discoloration after that was visually judged. ○: No discoloration to small △: Medium-sized ×: Large-sized (4) Freon resistance i) Swelling degree Pellets were pressed at 220 ° C to a thickness of 2 mm and 4 cm × 2
cm test sheet, then at -30 ℃ 6
Calculated from the weight change after immersion in HCFC-141b for 0 hours. The lower the value, the better the CFC resistance. ii) Critical strain 3.5 ounce injection molding machine, cylinder set temperature 2
After molding an injection-molded product having a thickness of 15 cm × 2 cm × 0.3 cm at 20 ° C., it was fixed to a cantilever jig, subjected to a deflection of 3 cm, and left in the steam of HCFC-141b. afterwards,
The amount of strain with cracks (maximum value: 1.3%) was obtained by folding by hand. The larger the value, the better the CFC resistance. (5) Gloss Using an injection molding machine of 3.5 ounces, an injection molded product having a thickness of 10 cm × 6 cm × 0.3 cm was prepared at a cylinder setting temperature of 240 ° C., and the surface gloss was measured according to ASTM-D523. .

[0039]

[Table-1]

[0040]

[Table-2]

[0041]

The ABS resin composition of the present invention has excellent chlorofluorocarbon resistance (HCFC-141b resistance) superior to conventional compositions.
In addition to having the properties), it has excellent mechanical strength, processability, appearance (gloss), thermal stability, etc., which are the characteristics of styrene resin. Therefore, alternative CFC (HCFC-141b)
It is highly useful as a material suitable for forming inner boxes of refrigerators and freezers using.

[Procedure amendment]

[Submission date] September 12, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

Reference Example 8 Graft Polymer Polymerization was carried out by the same procedure as in Reference Example 5 except that the agglomerated rubbery polymer latex obtained in Reference Example 3 (solid content 32.0%) was changed to 187 parts. A graft polymer having a graft ratio of 30% was obtained.

Claims (2)

[Claims] 1. A cyanide compound of 20 to 40% by weight and an aromatic vinyl compound of 80 to 60% by weight in the presence of a rubbery polymer of 20 to 80% by weight having a weight average particle size of 0.4 to 0.6 μm. Graft polymer (X) obtained by polymerizing 80 to 20% by weight of a monomer, and rubber polymer 40 having a weight average particle diameter of 0.05 to 0.2 µ.
Vinyl cyanide compound 30-4 in the presence of
Graft ratio 10 to 4 formed by polymerizing 5% by weight and 60 to 20% by weight of monomer of aromatic vinyl compound 70 to 55% by weight
Aggregated graft polymer (Y) obtained by aggregating 0% of small particle diameter graft polymer (y) into a tuft having a weight average particle diameter of 0.8 to 2.0 μ, and a vinyl cyanide compound of 35 to 45% by weight. Intrinsic viscosity obtained by polymerizing 65 to 55% by weight of aromatic vinyl compound 0.6
Is 0.9 to 0.9, and the weight ratio of the rubber polymer of the graft polymer (X) to the rubber polymer of the graft polymer (Y) is 1 to 1 to 4, An ABS resin composition having excellent chlorofluorocarbon resistance, characterized in that the total amount of the rubbery polymer is 15 to 25% by weight. 2. A refrigerator inner box having excellent chlorofluorocarbon resistance, which is formed from the composition according to claim 1.