JP2003277454A - Resin molding for high-temperature and high-humidity environment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a transparent resin molding for high-temperature and high- humidity environment, having slight change in transparency when exposed to a high-temperature and high-humidity environment. <P>SOLUTION: The resin molding for a high-temperature and high-humidity environment comprises a rubber-reinforced styrene-based resin which is constituted of a rubber-like polymer and an aromatic vinyl-based monomer or the aromatic vinyl-based monomer and another copolymerizable vinyl-based monomer, characterized in that (1) the weight-average particle diameter of the rubber-like polymer is 0.05-0.20 μm and (2) the difference in refractive index between an acetone-insoluble part and an acetone-soluble part in the resin is <0.02. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin molded article for a hot and humid environment. Specifically, for example, a resin molding for high temperature and high humidity environment that can be suitably used for applications that are exposed to high temperature and high humidity environments such as bathroom wall materials and counters, washrooms and kitchens, and that require transparency. Regarding goods.

[0002]

2. Description of the Related Art Manufactured under the names HIPS, ABS, etc.
The rubber-reinforced styrenic resin sold on the market is used for vehicle parts because it has excellent appearance, mechanical properties and moldability.
It is used in various fields such as electrical products. However, such a rubber-reinforced styrene resin is generally opaque, but depending on the product, transparency such as PMMA or polycarbonate resin may be required. In order to meet such a requirement, transparency can be obtained even in a rubber-reinforced styrenic resin by adjusting the composition ratio of each component constituting the resin, as described in, for example, JP-A-4-180907. It is generally known that it can be obtained.

However, for example, bathroom wall materials and counters,
When used in a washroom or kitchen, it is exposed to high temperature and high humidity environment, resulting in a problem that its transparency is significantly reduced and its product value is impaired. However, satisfactory materials have not yet been obtained at present.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a transparent resin molded article for a high temperature and high humidity environment with little change in transparency when exposed to a high temperature and high humidity environment. The purpose is.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in view of the above problems, and as a result, set the weight average particle diameter of the rubber-like polymer in a specific range and dissolve the resin in an acetone-insoluble matter and a soluble matter. By adjusting so that the difference in the refractive index from the resin content is less than 0.02, a transparent resin molding for high temperature and high humidity environment with little change in transparency when exposed to a high temperature and high humidity environment is obtained. The inventors have found that they can be obtained and reached the present invention. That is, the present invention is a rubber-reinforced styrenic resin comprising a rubber-like polymer and an aromatic vinyl-based monomer or another vinyl-based monomer copolymerizable therewith, the rubber-like polymer Has a weight average particle size of 0.05 to
The present invention provides a resin molded article for high temperature and high humidity environment, characterized in that the difference in refractive index between the acetone insoluble part and the soluble part in the resin is less than 0.02.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The rubber-reinforced styrene resin used in the present invention is composed of a rubber-like polymer and an aromatic vinyl monomer or another vinyl monomer copolymerizable therewith. More specifically, a graft polymer (a-1) obtained by polymerizing an aromatic vinyl monomer or another vinyl monomer copolymerizable therewith in the presence of a rubbery polymer. Alternatively, from the graft polymer (a-1) and the (co) polymer (a-2) obtained by polymerizing the aromatic vinyl monomer or another vinyl monomer copolymerizable therewith It will be.

The rubber-like polymer constituting the graft polymer (a-1) is polybutadiene, hydrogenated (partial).
Polybutadiene, polyisoprene, butadiene-styrene copolymer, hydrogenated (partial) butadiene-styrene copolymer, styrene-butadiene block copolymer, hydrogenated (partial) styrene-butadiene block copolymer, isoprene-styrene copolymer Polymer, butadiene-acrylonitrile copolymer, butadiene-isoprene-styrene copolymer, diene rubber such as polychloroprene, ethylene-
Examples include ethylene-propylene rubbers such as propylene copolymers, ethylene-propylene-non-conjugated diene (ethylidene norbornene, dicyclopentadiene, etc.) copolymers, acrylic rubbers such as polybutyl acrylate, etc., and one kind or two or more kinds. Can be used.

Aromatic vinyl monomers constituting the graft polymer (a-1) or (co) polymer (a-2) include styrene, α-methylstyrene, o-methylstyrene and p-methylstyrene. Styrene, m-methylstyrene and the like are mentioned, and one kind or two or more kinds can be used. Also,
Other vinyl monomers copolymerizable with the aromatic vinyl monomer include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, and (meth) acryl such as methyl methacrylate and methyl acrylate. Acid ester-based monomers, further maleimide-based monomers such as N-phenylmaleimide and N-cyclohexylmaleimide, acrylic acid,
Examples thereof include unsaturated carboxylic acids (anhydrides) such as methacrylic acid, maleic acid, and maleic anhydride, which may be used either individually or in combination of two or more, but are not limited to these monomers.

In order to achieve the object of the present invention, in the above rubber-reinforced styrene resin, the rubber-like polymer has a weight average particle diameter of 0.05 to 0.20 μm, and is compatible with the acetone-insoluble portion in the resin. It is necessary that the difference in the refractive index from the fusion zone is less than 0.02. When the weight average particle size of the rubber-like polymer is less than 0.05 μm, the impact strength as a resin molded product is remarkably reduced, and when it exceeds 0.20 μm, the transparency is greatly changed when exposed to a high temperature and high humidity environment. Becomes
It is not preferable because it impairs the product value as a transparent rubber-reinforced styrene resin. Preferably 0.05-0.15μ
m. If the difference in refractive index between the acetone-insoluble portion and the soluble portion in the resin exceeds 0.02, transparency is impaired, which is not preferable. The refractive index of the acetone-insoluble portion and the acetone-soluble portion is 0.02 by appropriately adjusting the type of rubber-like polymer to be used, the particle size thereof, the type of monomer to be used, and the proportion thereof. It can be less than.

The ratio of the rubber-like polymer contained in the rubber-reinforced styrene resin of the present invention is not particularly limited,
Preferably 15 to 60% by weight, more preferably 20 to 4
It is 5% by weight. If the proportion of the rubber-like polymer is less than 15% by weight, the impact strength tends to be poor, and if it exceeds 60% by weight, the moldability tends to be poor.

Regarding the graft polymer (a-1) and (co) polymer (a-2) constituting the rubber-reinforced styrene resin in the present invention, known emulsion polymerization method, suspension polymerization method and solution polymerization method are known. It can be obtained by a bulk polymerization method or a method in which these are arbitrarily combined.

The rubber-reinforced styrenic resin of the present invention may also contain known additives such as antioxidants [2,6-di-t.
-Butyl-4-methylphenol, 2- (1-methylcyclohexyl) -4,6-dimethylphenol, 2,2
-Methylenebis- (4-ethyl-6-t-methylphenol), 4,4'-thiobis- (6-t-butyl-3-)
Examples include methylphenol), dilaurylthiodipropionate, and tris (di-nonylphenyl) phosphite. ], UV absorber [pt-butylphenyl salicylate, 2,2'-dihydroxy-4-methoxybenzophenone, 2- (2'-hydroxy-4'-n-
Examples include octoxyphenyl) benzotriazole and the like. ], Hindered amine light stabilizers, lubricants [paraffin wax, stearic acid, hardened oil, stearamide,
Examples include methylene bis stearamide, ethylene bis stearamide, n-butyl stearate, ketone wax, octyl alcohol, lauryl alcohol, and hydroxystearic acid triglyceride. ], A dye etc. can be added if needed.

The method of mixing the respective components in the present invention is not particularly limited, and they can be mixed using an extruder, a Banbury mixer, a roll, a kneader or the like. Further, the processing method for obtaining the molded product in the present invention is not particularly limited, and an ordinary molding processing method such as an injection molding machine, a sheet extruder, a plate-shaped, convex-shaped, or a modified extruder such as a pipe is adopted. be able to. In addition, a sheet having a structure of two or more layers of the rubber-reinforced styrene resin in the present invention and another thermoplastic resin (for example, vinyl chloride resin, polycarbonate resin, polyester resin such as polyethylene terephthalate, polymethylmethacrylate resin) It is also possible to create a film or the like.

[Examples] In order to describe the present invention more specifically, examples and comparative examples will be described below. However, the present invention is not limited to these.

-Rubber-reinforced styrenic resin-Graft polymer (a-1-1): Polybutadiene latex (weight average particle diameter 0.1 μm) in a reactor substituted with nitrogen.
m, gel content 85%) 50 parts (solid content), water 150
Parts, ethylenediaminetetraacetic acid disodium salt 0.1 parts,
After adding 0.001 part of ferric sulfate and 0.1 part of sodium formaldehyde sulfoxylate and heating to 60 ° C., 3 parts of acrylonitrile, 12 parts of styrene, 35 parts of methyl methacrylate and cumene hydroperoxide of 0.
A mixture of 2 parts was continuously added over 3 hours, and the mixture was further polymerized at 60 ° C. for 2 hours. Then, after salting out, dehydration and drying, a graft copolymer (a-1-1) was obtained.

Graft polymer (a-1-2): 20 parts of polybutadiene latex (weight average particle diameter 0.13 μm, gel content 90%) (solid content), 5 parts of acrylonitrile, and styrene 19 in a reactor substituted with nitrogen. Parts, methyl methacrylate 56 parts, sodium formaldehyde sulfoxylate 0.4 parts, and cumene hydroperoxide 0.1 parts, in the same manner as in (a-1-1), except that the graft copolymer (a -1-2) was obtained.

Graft polymer (a-1-3): 50 parts (solid content) of styrene-butadiene latex (weight average particle diameter 0.12 μm, styrene content 25%, gel content 90%) in a reactor substituted with nitrogen. Water, 150 parts, ethylenediaminetetraacetic acid disodium salt 0.1 part, ferric sulfate 0.
Add 001 parts and 0.3 parts of sodium formaldehyde sulfoxylate, heat to 60 ° C., then add 20 parts of styrene,
A mixture of 30 parts of methyl methacrylate and 0.1 part of cumene hydroperoxide was continuously added over 3 hours, and the mixture was further polymerized at 60 ° C. for 2 hours. Then, after salting out, dehydration and drying, a graft copolymer (a-1-3) was obtained.

Graft polymer (a-1-4): Graft copolymer a- in the same manner as a-1-1 except that a polybutadiene latex having a weight average particle diameter of 0.3 μm was used.
1-4 were obtained.

Graft polymer (a-1-5): Graft copolymer a in the same manner as in a-1-1 except that a polybutadiene latex having a weight average particle diameter of 0.03 μm was used.
-1-5 was obtained.

Copolymer (a-2-1): A reactor purged with nitrogen was charged with 130 parts of pure water and 0.1 part of potassium persulfate, and then heated to 60 ° C. with stirring. Thereafter, 30 parts of an aqueous emulsifier solution containing 6 parts of acrylonitrile, 24 parts of styrene and 70 parts of methyl methacrylate and 2 parts of disproportionated potassium rosinate were added to each of 4 parts.
After continuous addition over a period of time, the polymerization system was heated to 60 ° C. and aged for 2 hours to complete the polymerization. Salting out, dehydration,
After drying, a copolymer a-2-1 was obtained.

Copolymer (a-2-2): A copolymer a-2-2 consisting of 25 parts of styrene and 75 parts of methyl methacrylate was obtained based on a known bulk polymerization method.

Copolymer (a-2-3): Copolymer a-2- except that styrene 40 parts and methyl methacrylate 60 parts are used as monomers.
Got 3.

Copolymer (a-2-4): A copolymer (a-2) was prepared in the same manner as in (a-2-2) except that 30 parts of acrylonitrile and 70 parts of styrene were used as the monomers.
-4 was obtained.

[Examples 1 to 4 and Comparative Examples 1 to 4] With respect to each of the above components, 1 part of ethylenebisstearylamide was added as a lubricant to a mixture having a mixing ratio shown in Tables 1 and 2, and then 40 mm. Pellets were obtained by melt-kneading at 200 ° C. using a single screw extruder. The following analysis and evaluation were performed on the obtained pellets. The results are shown in Table 1 and Table 2.
Shown in.

Refractive index : 10 g of the obtained pellet was left standing in 300 ml of acetone for 24 hours and then 12000 rp
Centrifugation was performed at a speed of m to separate the acetone-soluble portion and the insoluble portion. The soluble portion was concentrated using a rotary evaporator, reprecipitated in methanol, and recovered using a glass filter (2G-2). After drying the obtained soluble and insoluble parts respectively in a vacuum dryer at 40 ° C for 8 hours, a film was prepared at a temperature of 210 ° C using a press molding machine and the refractive index was measured using an Appe refractometer. Was measured.

Weight-average particle diameter of rubber-like polymer: The weight-average particle diameter of the rubber-like polymer was obtained by cutting an ultrathin section from the prepared pellet, staining it with osmium tetroxide, and photographing it with a transmission electron microscope. Image analysis device for photos (Asahi Kasei
It was determined by measuring the weight average particle diameter of 2000 rubber particles using (IP1000PC).

Transparency : Using a 1 ounce injection molding machine (manufactured by Yamashiro Seiki), cylinder temperature 200 ° C, mold temperature 50 ° C
After a test piece having a thickness of 3 mm was prepared under the conditions described above, the haze (initial value) was measured using a reflectance / transmittance meter HR-100 (manufactured by Murakami Color Research Laboratory). High temperature and humidity environment (Δ haze):

Izod impact strength : ASTM D-25
The Izod impact strength was measured according to 6. Unit: J
/ M.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

As described above, the rubber-reinforced styrenic resin of the present invention has little change in transparency when exposed to a hot and humid environment, and is suitable for use in bathroom wall materials and counters, washrooms and kitchens. It can be suitably used in applications where it is exposed to such a hot and humid environment and transparency is required.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keisuke Nishii             8-8 Nihonbashi Kabutocho, Chuo-ku, Tokyo             Within I and L Co., Ltd. F-term (reference) 4F071 AA10X AA12 AA12X AA15X                       AA22X AA32X AA33X AA34X                       AA35X AA36X AA77 AA80                       AE05 AF10 AF30 AF31 AF45                       AF53 AH19 BA01 BB05 BB06                       BC01 BC17                 4J026 AA12 AA13 AA45 AA67 AA68                       AA69 AA71 AA72 AC02 AC09                       AC10 AC11 AC12 AC32 BA04                       BA05 BA06 BA25 BA27 BA31                       BA32 BA34 BB01 BB03 DB02                       DB03 DB04 DB05 DB15 GA08

Claims (3)

[Claims] 1. A rubber-reinforced styrene-based resin comprising a rubber-like polymer and an aromatic vinyl-based monomer or another vinyl-based monomer copolymerizable therewith, said rubber-like polymer comprising: The weight average particle diameter is 0.05 to 0.20 μm, and the difference in refractive index between the acetone insoluble portion and the soluble portion in the resin is 0.
A resin molded product for high temperature and high humidity environment, which is less than 02. 2. The rubber-like polymer has a weight average particle diameter of 0.0.
The resin molded product for hot and humid environment according to claim 1, which has a thickness of 5 to 0.15 μm. 3. A haze change (Δ) with respect to an initial haze value when the resin molded product is exposed to an environment of 70 ° C. and 90% RH.
The haze) is 3 or less, and the resin molded article for a hot and humid environment according to claim 1 or 2.