JPH04359954A - Transparent resin composition - Google Patents

Abstract

PURPOSE:To prepare the title compsn. exhibiting a high transparency by mixing an arom. polycarbonate with a specific methacrylate copolymer. CONSTITUTION:An arom. polycarbonate is mixed with a copolymer comprising 50-98wt.% phenyl methacrylate units, 1-49wt.% methyl methacrylate units, 1-49wt.% monomer units consisting of at least one kind of monomer unit selected from the group consisting of acrylate units and methacrylate units other than a phenyl methacrylate unit and a methyl methacrylate unit, and 0-48wt.% copolymerizable monomer units.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a thermoplastic transparent resin composition, and more particularly to a highly transparent composition comprising an aromatic polycarbonate, particularly a bisphenol A polycarbonate, and a phenyl methacrylate copolymer. .

0002

BACKGROUND OF THE INVENTION Generally, compositions of polycarbonate and polymethyl methacrylate do not form a uniform transparent resin as described in Japanese Patent Publication No. 16063/1982, but instead form an opaque resin with pearlescent luster. Therefore, compositions that maintain the high transparency possessed by both resins have been studied and disclosed.

Japanese Patent Publication No. 56-28937 describes a composition of a low molecular weight acrylic copolymer consisting of polycarbonate and 75 to 90% by weight of methyl methacrylate and 10 to 25% by weight of alkyl acrylate. However, in order for the acrylic copolymer to become transparent when mixed with polycarbonate, it is necessary to reduce the molecular weight to 15,000 or less, and such low-molecular-weight substances only act as plasticizers, and when mixed in large quantities, they can cause significant damage. This causes a decrease in physical properties.

[0004] Japanese Patent Laid-Open No. 61-283642 describes C1
Compositions of polycarbonate and copolymers of ~C10 alkyl (meth)acrylates and ultraviolet absorbing monomers are described. The copolymers are very specialized and expensive, making them impossible to use on a wide scale. JP-A-63-90551 discloses a copolymer of methyl methacrylate and monosubstituted (meth)acrylamide, and JP-A-63-256647 discloses a copolymer of methyl methacrylate and maleimide. 1986-1
No. 749 describes that a copolymer consisting of methyl methacrylate and a (meth)acrylate having a carbocyclic group is transparently compatible with polycarbonate, but in both cases, the copolymer is transparently compatible with polycarbonate at the temperature at which polycarbonate is normally melt-molded. There are 2
At 50 to 300°C, a thin film appears transparent, but when the thickness is several mm, it becomes opaque, which poses a practical problem.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly transparent composition comprising an aromatic polycarbonate, particularly a bisphenol A polycarbonate, and a phenyl methacrylate copolymer.

[0006]

[Means for Solving the Problems] The present inventor has conducted extensive research into a methacrylate copolymer that is transparently compatible with aromatic polycarbonate, especially after hot melt molding at a temperature of 250 to 300°C. As a result, it was found that a phenyl methacrylate copolymer was suitable for this purpose, and the present invention was completed.

That is, the present invention provides a composition of an aromatic polycarbonate and a methacrylate copolymer in which the methacrylate copolymer has 5 phenyl methacrylate units.
0 to 98% by weight, 1 to 50% by weight of methyl methacrylate units, and ethyl acrylate, cyclohexyl acrylate, 4-t-butylcyclohexyl acrylate,
One or more monomer units selected from phenyl acrylate, 4-t-butylphenyl acrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenoxyethyl acrylate, and 2-phenoxyethyl methacrylate. 5
The present invention provides a thermoplastic transparent resin composition characterized in that it is a copolymer consisting of 0% by weight and 0 to 48% by weight of monomer units copolymerizable with the monomer units described above.

[0008] If the composition of the phenyl methacrylate copolymer deviates from the above composition range, transparency will be impaired when mixed with polycarbonate. Examples of acrylate or methacrylate monomers other than phenyl methacrylate and methyl methacrylate include ethyl acrylate, cyclohexyl acrylate, 4-t-butylcyclohexyl acrylate, phenyl acrylate, 4-t
-butylphenyl acrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, and the like.

Examples of monomers copolymerizable with the above monomer units include aromatic vinyls such as styrene and α-methylstyrene, acrylonitrile, methacrylonitrile, and butadiene. The molecular weight of the methacrylate copolymer is not particularly limited, but is preferably in the range of 50,000 to 300,000; if it is less than 50,000, the strength of the composition may decrease;
If it exceeds 300,000, melt molding may become difficult.

[0010] The phenyl methacrylate copolymer can be produced by any known method, and radical polymerization is particularly preferred, such as bulk polymerization, solution polymerization, or suspension polymerization. The radical initiators used here include azo compounds such as azobisisobutyronitrile, organic peroxides such as lauroyl peroxide, and di-t-butyl peroxide.

Chain transfer agents for controlling molecular weight include alkyl mercaptans such as octyl mercaptan. The composition of the present invention includes ultraviolet absorbers such as benzotriazole type and benzophenone type, hindered amine type light stabilizers, antioxidants such as hindered phenol type, lubricants such as higher alcohols and glycerides, flame retardants, and plasticizers. ,
Antistatic agents, coloring agents such as dyes and pigments, etc. can be added.

0012

[Examples] Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

[0013]

[Examples 1 to 3] In a 10-liter beaker, 9 g of lauroyl peroxide and 5 g of n-octyl mercaptan were added to 6000 g of an aqueous phase prepared using Poval as a suspending agent for 3000 g of each monomer composition listed in Table 1.
．． After mixing and adding 4 g of the mixture, polymerization was started at 75°C, and then the temperature was raised to 95°C to complete the polymerization. The final polymerization rate is 99.5%. Wash and dry to obtain acrylic resin. The molecular weight of each of the obtained acrylic resins is around 150,000.

These acrylic resins and polycarbonate resin (Macrolon 3103 manufactured by Bayer) were mixed in a weight ratio of 3
10 at 270°C using a Brabender at a ratio of 97 to 97.
After kneading for a minute, the mixture is molded at 270° C. using a 37-ton compression molding machine (manufactured by Shoshi Tekko Co., Ltd.) to obtain a sheet with a thickness of 2 mm. Using these sheets, JIS K7105
Table 1 shows the haze values measured based on.

[0015]

[Comparative Examples 1 to 3] Using the monomer compositions shown in Table 1, the same procedure as in Example was carried out, and the haze was measured. Table 1 shows the results.

[0016]

[Table 1]

[0017]

Effects of the Invention The specific methacrylate copolymer of the present invention, in a mixed composition with an aromatic polycarbonate,
This shows an unprecedented level of transparency.

Claims (1)

[Claims] Claim 1: In a composition of an aromatic polycarbonate and a methacrylate copolymer, the methacrylate copolymer contains 50 to 98% by weight of phenyl methacrylate units;
1 to 49% by weight of methyl methacrylate units, and 1 to 49% by weight of one or more monomer units selected from acrylates or methacrylates other than phenyl methacrylate and methyl methacrylate, copolymerizable with the above monomer units A thermoplastic transparent resin composition characterized by being a copolymer containing 0 to 48% by weight of monomer units.