JP2006016468A - Heat resistant and transparent resin composition and variety of parts molded by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-resistant and transparent resin composition that has excellent transparency, heat resistance and impact resistance and provides a variety of molded parts therefrom. <P>SOLUTION: This heat-resistant and transparent resin composition comprises (A) a graft copolymer that is produced by grafting the monomer mixture of 40 to 90 pts.wt. in total comprising 60-80 wt.% of (meth)acrylic ester and 40 to 20 wt.% of styrene in the presence of 5 to 60 wt.% of a rubber polymer including 3 to 10 wt.% of styrene and 97 to 90 wt.% of butadiene, (B) a copolymer from 20 to 28 wt.% of vinyl cyanide and 80 to 72 wt.% of styrene and (C) a copolymer from 1 to 20 wt.% of styrene, 50 to 84 wt.% of (meth)acrylic ester and 15 to 30 wt.% of imide where the amount of the graft polymer (A) is 5 to 50 pts.wt. per 100 pts.wt. of (A + B + C in total) and the total of the copolymer (B) and the copolymer (C) is 95 to 50 pts.wt., and the ratio of (B) : (C) is 2 : 98 to 15 : 85. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-resistant transparent resin composition excellent in heat resistance, transparency and impact strength, and further, parts for mobile terminals such as mobile phones and PDAs formed from the composition, audio, and car navigation. The present invention relates to various molded parts such as vehicle parts, liquid crystal TV parts, and light guide plates.

As a result of the rapid spread of mobile information terminals such as mobile phones recently, equipment such as large LCD screens and built-in camera functions are standard equipment to cope with the rapidly increasing amount of information, and the structure of the terminal is more complicated. It has become a thing.
For example, when considering a mobile phone, the base casing incorporates many parts such as a liquid crystal part for displaying images, a camera lens part, and a lamp part for notifying incoming calls. The method is complex and laborious and never productive. In order to deal with such problems, attempts have been made to manufacture these parts integrally. For example, 1) impact strength is insufficient when polymethylmethacrylate resin is used for the casing, and 2) polycarbonate. When a resin is used, the fluidity is insufficient, so that it is difficult to form a thin wall and it has not been put into practical use.
Therefore, it has been desired to develop a material having sufficient transparency, impact strength, moldability and heat resistance.

On the other hand, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. Hei 6-279646) discloses a specific methyl methacrylate-α-methylstyrene copolymer to obtain a resin composition having excellent heat resistance without losing transparency. A resin composition composed of a polymer and a specific styrene-conjugated diene block copolymer is disclosed in Patent Document 2 (Japanese Patent Application Laid-Open No. 2001-294722) from a specific methacrylate ester-aryl maleimide-alkyl maleimide. However, it is difficult to adjust the balance between transparency and heat resistance because they use special copolymers. I was not satisfied with it.
JP-A-6-279646 JP 2001-294722 A

  An object of the present invention is to provide a resin composition excellent in the balance of transparency, impact strength, moldability and heat resistance, and various molded parts molded from these resin compositions.

That is, the present invention provides (meth) acrylic acid in the presence of 5 to 60 parts by weight of a 0.05 to 0.3 μm rubbery polymer comprising 3 to 10% by weight of a styrene monomer and 97 to 90% by weight of butadiene. Graft polymer (A) obtained by graft polymerization of monomers (total) 40 to 95 parts by weight of acid ester monomer 60 to 80% by weight and styrene monomer 40 to 20% by weight, vinyl cyanide Copolymer (B) comprising 20 to 28% by weight of styrene monomer and 80 to 72% by weight of styrene monomer, 1 to 20% by weight of styrene monomer, (meth) acrylate monomer A composition comprising a copolymer (C) comprising 50 to 84% by weight and an imide monomer 15 to 30% by weight, and per 100 parts by weight of the resin composition (A + B + C), the graft polymer (A) 5 to 50 parts by weight And 95 to 50 parts by weight in total of the copolymer (B) and the copolymer (C), and the ratio of (B) :( C) is 2:98 to 15:85. A heat resistant transparent resin composition is provided.

A resin composition excellent in the balance of transparency, impact strength, moldability and heat resistance is obtained, and can be suitably used as various molded parts.

The present invention will be described in detail below.
The rubber-like polymer constituting the graft polymer (A) in the present invention is a copolymer composed of styrene and butadiene, but when the styrene content is less than 3% by weight, the polymerization rate is remarkably reduced and the present invention is characterized. If the transparency is less than 10% by weight, it is not preferable because the low-temperature characteristics are deteriorated and the transparency which is a feature of the present invention is also insufficient. Moreover, the weight average particle diameter is 0.05-0.3 micrometer. If it is less than 0.05 μm, it is difficult to obtain a sufficient impact strength, and if it exceeds 0.3 μm, the transparency tends to be remarkably impaired. The particle size of the rubber-like polymer can be arbitrarily adjusted by changing the polymerization conditions, that is, the type and amount of the initiator, the polymerization rate, the temperature during the polymerization, or the stirring conditions. It is.
As a polymerization method for these rubbery polymers, an emulsion polymerization method is generally used, but other polymerization methods such as a solution polymerization method and a bulk polymerization method, or any combination thereof may be used depending on the purpose. .

Examples of the (meth) acrylic acid ester monomer constituting the graft polymer (A) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylexyl. Examples of styrene monomers include acrylate, styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methyl-p-methylstyrene, halogenated styrene, ethylstyrene. , P-isopropylstyrene, pt-butylstyrene, 2,4-dimethylstyrene, divinylbenzene and the like are exemplified, and one or two or more of them can be selected and used, respectively.

  The graft polymer (A) is composed of 60 to 80% by weight of (meth) acrylate monomer and 40 to 20% by weight of styrene monomer in the presence of 5 to 60 parts by weight of the rubbery polymer. The obtained monomer (total) is obtained by graft polymerization of 40 to 95 parts by weight. When the amount of the rubbery polymer is less than 5 parts by weight, it is difficult to obtain a sufficient product strength. Further, when the (meth) acrylic acid ester monomer is less than 60% by weight or more than 80% by weight with respect to the monomers (total) to be used for grafting, it is not preferable because transparency is impaired.

Examples of the vinyl cyanide monomer constituting the copolymer (B) in the present invention include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, and the styrene monomer includes styrene, α-methyl. Styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl-p-methyl styrene, halogenated styrene, ethyl styrene, p-isopropyl styrene, pt-butyl styrene, 2,4-dimethyl Styrene, divinylbenzene and the like are exemplified, and one or more can be selected and used.
The copolymer (B) is composed of 20 to 28% by weight of vinyl cyanide monomer and 80 to 72% by weight of styrene monomer. If the vinyl cyanide monomer is less than 20% by weight or more than 28% by weight, the compatibility with the copolymer (C) is greatly lowered, which is not preferable. Particularly preferred are 22 to 26% by weight of vinyl cyanide monomer and 78 to 74% by weight of styrene monomer.

Examples of the styrene monomer constituting the copolymer (C) in the present invention include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methyl-p-methylstyrene. , Halogenated styrene, ethyl styrene, p-isopropyl styrene, pt-butyl styrene, 2,4-dimethyl styrene, divinyl benzene, etc., as the (meth) acrylic acid ester monomer, methyl (meth) acrylate, Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylexyl acrylate, etc., as imide monomers, maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide Etc., and one or more types are selected and used. It is possible.
The copolymer (C) in the present invention comprises 1 to 20% by weight of a styrene monomer, 50 to 84% by weight of a (meth) acrylic acid ester monomer, and 15 to 30% by weight of an imide monomer. It is a copolymer. If the composition ratio is out of the above range, the refractive index is significantly different from that of the graft polymer (A). In particular, if the imide monomer is less than 15% by weight, sufficient heat resistance cannot be obtained, and if it exceeds 30% by weight, the fluidity is extremely lowered, which is not preferable.

There are no particular limitations on the polymerization method of the graft polymer (A), copolymer (B), and copolymer (C) in the present invention, and an emulsion polymerization method, a solution polymerization method, a bulk polymerization method, or any of these may be used. Combinations are also possible. However, the suspension polymerization method and the bulk polymerization method are preferable from the viewpoints of transparency and hygroscopic whitening.
The weight average molecular weight and molecular weight distribution of the copolymers (B) and (C) are not particularly limited, but the weight average molecular weight is 50,000 to 150,000 from the viewpoint of balance between moldability and impact strength, and the molecular weight distribution (Q The value is preferably in the range of 2-3. The weight average molecular weight and molecular weight distribution of the copolymers (B) and (C) can be adjusted by changing the polymerization conditions, that is, the type and amount of the initiator, the polymerization rate, the polymerization temperature, or the stirring conditions. It is possible to adjust arbitrarily by doing.

The heat-resistant transparent resin composition of the present invention has a total of 95 to 50 parts by weight of graft polymer (A) and copolymer (B) and copolymer (C) per 100 parts by weight (total of A + B + C). -50 parts by weight, and the ratio of (B) :( C) is 2: 98-15: 85. If the graft polymer (A) is less than 5 parts by weight, sufficient impact strength cannot be obtained, and if it exceeds 50 parts by weight, the fluidity is remarkably lowered, which is not preferable. When the ratio of (B) :( C) is outside the range of 2:98 to 15:85, a resin composition excellent in the balance of transparency and heat resistance, which is the object of the present invention, cannot be obtained.

The refractive index difference between the acetone soluble part and the insoluble part in the heat resistant transparent resin composition in the present invention needs to be 0.02 or less. The refractive index of the acetone-insoluble part and the acetone-soluble part is set to less than 0.02 by appropriately adjusting the particle diameter of the rubber-like polymer to be used, the type of the monomer to be used, and the use ratio thereof. It is possible.

In addition, the mixing method of the various polymers (A), (B), and (C) obtained by the present invention is mixed in a latex state, mixed in a powder state, and in a pellet state regardless of the form of the raw material. Mixtures of these or combinations thereof can be employed depending on the purpose.

The melt flow rate of the heat-resistant transparent resin composition in the present invention (220 ° C., 10 kg load: conforming to ASTM D-1238) is not particularly limited, but may be in the range of 2 g / 10 min to 30 g / 10 min. It is preferable from the viewpoint of moldability.

The residual monomer amount in the heat-resistant transparent resin composition in the present invention is preferably less than 1500 ppm. When the residual monomer amount exceeds 1500 ppm, the heat resistance is lowered by the residual monomer, which is not preferable. The residual monomer amount can be adjusted by appropriately setting the temperature conditions and the discharge amount, the number of vent ports, the position, and the degree of vacuum during the stripping step during the polymerization or granulation.

Furthermore, pigments, dyes, antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, and the like can be added to the heat-resistant transparent resin composition of the present invention as necessary. Agents << bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (1,2,2,6, 6-pentamethyl-4-piperidinyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2 -Bis (1,2,2,6,6-pentamethyl-4-piperidyl) -n-butylmalonate, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-succinate Tetramethyl Peridine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {2,2,6,6-tetramethyl -4-piperidyl} imino] hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino} >>, N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [ N-butyl-N- (1,2,2.6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (1-octyloxy-2,2,6 , 6-Tetramethyl-4-piperidyl) sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloxy-2,2,6,6-tetramethylpiperidine, etc., especially with a molecular weight of 600 or more Compound Is preferable ”or antioxidant << 2-6-di-t-butyl-4-methylphenol, n-octadecyl-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl)- Propionate, 2-2'-methylenebis (4-methyl-6-t-butylphenol), tetrakis- {methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate} -methane , 2-t-butyl-6- (3′-t-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate and the like, phenolic antioxidants, trisnonyl phosphite, trisphenyl phosphite Phosphorous antioxidants such as phyto, and silicon compounds << polydimethylsiloxane, polymethylethylsiloxane, polydiethylsiloxa It is preferable that polymethylphenylsiloxane, polydiphenylsiloxane, etc. are added from the viewpoint of preventing discoloration of the product during processing. These addition amounts are respectively 0.01 to 5 parts by weight of at least one kind of hindered amine light stabilizer or antioxidant and 0.02 to 0.1 parts of silicon compound per 100 parts by weight of the resin composition. It is preferable that it is a weight part. Outside of the above range, defects that impair the appearance of the product are likely to occur due to gas generated during molding, bleed-out, or the like.

With the heat-resistant transparent resin composition of the present invention, a desired molded product can be easily produced by a normal injection molding method. In addition, it is possible to employ an injection molding method of two or more colors, a heat cycle molding method, an injection-compression molding method, or the like using an injection molding machine having a plurality of cylinders in combination with another thermoplastic resin. In addition to the injection molding method, it is also possible to adopt a modified extrusion method such as a sheet, extrusion, and pipe. Although there is no restriction | limiting in particular about the processing temperature at the time of shaping | molding, It is preferable that it is the range of 200-280 degreeC from a viewpoint which prevents coloring of a molded article.

The above-mentioned transparent molded resin parts obtained by molding the resin composition of the present invention include parts for mobile terminals such as mobile phones and PDAs, parts for vehicles such as audio and car navigation, parts for liquid crystal TVs, light guide plates, etc. It can be suitably used as various molded resin parts.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not restrict | limited at all by these.

Graft polymer (A)
A-1 : From a styrene-butadiene rubber latex (styrene 5 wt%, weight average particle diameter 0.25 μm) 50 parts by weight (solid content), methyl methacrylate 35 parts by weight, and styrene 15 parts by weight by a known emulsion polymerization method. Graft polymer A-1 was obtained.
A-2 : Styrene-butadiene rubber latex (5% by weight of styrene, weight average particle size 0.1 μm) 50 parts by weight (solid content), 35 parts by weight of methyl methacrylate, 15 parts by weight of styrene by the same method as A-1. A graft polymer A-2 comprising:
A-3 : 50 parts by weight (solid content) of styrene-butadiene rubber latex (10% by weight of styrene, 0.3 μm weight average particle diameter), 30 parts by weight of methyl methacrylate, 20 parts by weight of styrene by the same method as A-1. A guft polymer A-3 comprising:
A-i : 50 parts by weight (solid content) of styrene-butadiene rubber latex (styrene 5 wt%, weight average particle size 0.03 μm), 35 parts by weight of methyl methacrylate, 15 parts by weight of styrene by the same method as A-1. A graft polymer A-i was obtained.
A-ii : Styrene-butadiene rubber latex (styrene 5 wt%, weight average particle size 0.1 μm) 50 parts by weight (solid content), methyl methacrylate 5 parts by weight, styrene 45 parts by weight in the same manner as A-1. A graft polymer A-ii comprising:

Copolymer (B)
B-1 : A copolymer B-1 composed of 25% by weight of acrylonitrile and 75% by weight of styrene was obtained by a known emulsion polymerization method. The copolymer B-1 had a polystyrene equivalent weight average molecular weight of about 100,000 and a Q value of 2.7.
Bi : A copolymer Bi comprising 15% by weight of acrylonitrile and 85% by weight of styrene was obtained by a known emulsion polymerization method. The copolymer Bi had a polystyrene equivalent weight average molecular weight of about 90,000 and a Q value of 2.6.

Copolymer (C)
C-1 : A copolymer C-1 comprising 5% by weight of styrene, 65% by weight of methyl methacrylate and 30% by weight of cyclohexylmaleimide was obtained by a known emulsion polymerization method. The copolymer C-1 had a polystyrene equivalent weight average molecular weight of about 70,000 and a Q value of 2.1.
C-2 : A copolymer C-2 comprising 5% by weight of styrene, 65% by weight of methyl methacrylate and 30% by weight of N-phenylmaleimide was obtained by a known emulsion polymerization method. The copolymer C-2 had a polystyrene equivalent weight average molecular weight of about 70,000 and a Q value of 2.2.
Ci : A copolymer Ci comprising 40% by weight of styrene, 30% by weight of methyl methacrylate, and 30% by weight of cyclohexylmaleimide was obtained by a known emulsion polymerization method. The copolymer Ci had a polystyrene equivalent weight average molecular weight of about 60,000 and a Q value of 2.1.

D-1 : Hindered amine light stabilizer (Adeka Stub LA-77G manufactured by Asahi Denka Kogyo Co., Ltd.)
D-2 : Phosphorous antioxidant (Adeka Stub 135A manufactured by Asahi Denka Kogyo Co., Ltd.)

Examples and Comparative Examples After mixing various components at the ratios shown in Table 1, using a 40 mm single screw extruder with a vent (manufactured by Tanabe Plastics Co., Ltd.), melt mixing at a set temperature of 270C. Went. In addition, 1 part of ethylenebisstearylamide was added to all samples as a lubricant. The obtained pellets were prepared using a 3.5 ounce vertical injection molding machine (SAV-100, manufactured by Yamashiro Seiki Co., Ltd.) under conditions of a cylinder temperature of 260 ° C. and evaluated by the following test method. Carried out.

In the examples, various evaluations were performed by the following methods.
Impact strength : Charpy impact strength was measured according to ISO 179. Unit: kJ / m ²
Heat resistance : The deflection temperature under load was measured according to ISO 75. Unit: ° C
Transparency : Haze was measured using a reflection / transmittance meter HR-100 (manufactured by Murakami Color Research Laboratory).
Thermal stability : Using a 3.5 ounce vertical injection molding machine (SAV-100, manufactured by Yamashiro Seiki Co., Ltd.), a flat plate of 50 mm x 75 mm x 3 mm was subjected to a cycle of 5 minutes at a cylinder temperature of 260 ° C. Continuous molding was performed, and the hue difference (ΔE) between the first shot and the sixth shot was measured using a color difference meter (manufactured by Color Computer Shimadzu Corporation).

The heat-resistant transparent resin composition in the present invention is extremely excellent in heat resistance, transparency, moldability, and dimensional stability. Parts for mobile terminals such as mobile phones and PDAs that require these performances, audio, It is very effective as molded resin parts such as car parts such as car navigation systems, liquid crystal TV parts, and light guide plates.

Claims (8)

(Meth) acrylate monomer in the presence of 5 to 60 parts by weight of a 0.05 to 0.3 μm rubbery polymer comprising 3 to 10% by weight of styrene monomer and 97 to 90% by weight of butadiene Graft polymer (A) obtained by graft polymerization of monomers (total) 40 to 95 parts by weight of 60 to 80% by weight and styrene monomer 40 to 20% by weight, vinyl cyanide monomer 20 to Copolymer (B) comprising 28% by weight and 80 to 72% by weight of styrene monomer, 1 to 20% by weight of styrene monomer, 50 to 84% by weight of (meth) acrylate monomer and It is a composition comprising a copolymer (C) consisting of 15 to 30% by weight of an imide monomer, and 5 to 50 parts by weight of the graft polymer (A) per 100 parts by weight of the resin composition (A + B + C). And a copolymer ( ) And 95-50 parts by weight in total of the copolymer (C), and the ratio of (B) :( C) 2: 98~15: heat-resistant transparent resin composition, which is a 85. The heat-resistant transparent resin composition according to claim 1, wherein the weight average molecular weights of the copolymers (B) and (C) are in the range of 50,000 to 150,000. The heat resistance according to claim 1 or 2, wherein 0.01 to 5 parts by weight of at least one kind of hindered amine light stabilizer or antioxidant is added per 100 parts by weight of the resin composition (A + B + C). Transparent resin composition. The heat resistant transparent resin composition according to any one of claims 1 to 3, wherein 0.02 to 0.1 parts by weight of a silicon compound is added per 100 parts by weight of the resin composition (A + B + C). A portable terminal part such as a mobile phone, a PDA, or a personal computer molded using the resin composition according to any one of claims 1 to 4. Vehicle parts, such as an audio and a car navigation, shape | molded using the resin composition in any one of Claims 1-4. The component for liquid crystal TV shape | molded using the resin composition in any one of Claims 1-4. The light-guide plate shape | molded using the resin composition in any one of Claims 1-4.