JPS6241979B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to novel blends of methyl methacrylate-styrene copolymers and acrylonitrile-styrene monomer copolymers having improved optical, mechanical, gas shearing properties and significantly improved processability. The blend of this invention consists of two polymer components. Namely, one is a copolymer of methyl methacrylate and styrene, and the other is a nitrile copolymer containing large amounts of polymerized acrylonitrile, styrene, and optionally diene rubber. Both polymer components are thermoplastics. The thermoplastic nitrile resin useful in this invention comprises a large amount of an olefinically unsaturated nitrile such as acrylonitrile, a small amount of another monomer component copolymerizable with the olefinically unsaturated nitrile, and optionally a conjugated diene rubber. Manufactured by polymerization. Conjugated diene monomers useful in this invention include butadiene-1,3, isoprene, chloroprene,
Bromoprene, cyanoprene, 2,3-dimethylbutadiene-1,3,2-ethylbutadiene-
Includes 1,3,2,3-diethylbutadiene-1,3 and the like. Most preferred are butadiene and isoprene. The olefinic unsaturated nitriles useful in this invention have the structure

It is an α,β-olefinically unsaturated mononitrile having the formula: where R is hydrogen, a lower alkyl group having 1 to 4 carbon atoms, or a halogen. Such compounds include acrylonitrile, alpha
-Includes chloroacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, ethacrylonitrile, etc. Most preferred are acrylonitrile, methacrylonitrile and mixtures thereof. The nitrile polymer effective in this invention contains 100 parts by weight of 50% by weight or more of nitrile (A) and 100 parts by weight of styrene (B) of 50% by weight or less based on (A)+(B), and 0 parts by weight of the rubbery polymer (C).
It is obtained by polymerization in the presence of ~40 parts by weight. Here, (A) is the structure

[Formula] (R is as defined above), and (C) is a conjugated diene monomer selected from the group consisting of butadiene and isoprene, optionally styrene, structure

Nitrile monomer and structure having [formula] (R is as above)

[Formula] (R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a halogen, and R ₂ is an alkyl group having 1 to 6 carbon atoms.) A rubbery polymer containing 50-100% by weight of polymerized conjugated diene and 0-50% by weight of comonomer. In the nitrile polymer, (A) is 70 to 90% by weight
It is desirable that Copolymers of methyl methacrylate and styrene useful in this invention are those comprising 50-70% by weight of methyl methacrylate and the corresponding 50-30% by weight of styrene. Blends of methyl methacrylate-styrene copolymers and nitrile copolymers range from 2 to 60% by weight.
Preferably 5 to 50% by weight of methyl methacrylate.
It is made from a styrene copolymer and a corresponding approximately 98-40% by weight, preferably 95-50% by weight, of a nitrile copolymer. The methyl methacrylate-styrene copolymer and nitrile copolymer components of the blends of this invention can be prepared by adding the monomers and other components by any of the known common polymerization methods, including bulk polymerization, solution polymerization, and emulsion or suspension polymerization. They can also be produced in batches, continuously or by intermittent addition. Typically, these copolymers are substantially free of molecular oxygen;
It is prepared in an aqueous medium in the presence of an emulsifying or suspending agent and a free radical-generating polymerization initiator at a temperature of about 0 to 100°C. The blends have unexpectedly good gas shedding properties that are far superior to those expected from the gas shedding properties of the respective copolymers. The novel polymer blends of this invention are thermoplastics that can be easily processed and thermoformed into a wide variety of useful products by any conventional method such as dispensing, extrusion, molding, drawing, blow molding, etc. Becomes a material. The polymer blends of this invention have excellent solvent resistance and, when rubber modified, their low gas permeability and impact resistance make them useful in the production of pipes, conduits, rods, bottles, film and sheet coatings. Become something. In the examples set forth below, amounts of ingredients are given in parts by weight unless otherwise indicated. Example 1 A Weight ratio of methyl methacrylate to styrene 60:40
A blend was prepared by milling a mixture of 5 parts of a homogeneous copolymer with acrylonitrile to styrene in a weight ratio of 80:20 for 4 minutes at 160°C on a two roll mill;
Test plaques were prepared by compression molding at 70.3 kg/cm ² (gauge pressure). The oxygen permeability of the compressed films obtained from the plaques was measured using an Oxtran 1050 meter at 23° C. and 100% relative humidity. The oxygen transmission rate was found to be 0.6 cc/mil/100 square inches/24 hours/atmospheric pressure (1 mil = 1/1000 inch). Other properties of this blend include flexural modulus of 44,300 Kg/cm ² and 18.6
The ASTM heat distortion temperature in kg/cm ² was 95°C. B The ratio of methyl methacrylate to styrene is 60:40.
A polymer plaque outside the scope of the present invention was prepared by repeating the above procedure A using 100 parts of the copolymer and without using the acrylonitrile-styrene copolymer. It was found that this has the following properties. :Oxygen permeation rate, 40.2
cc/mil/100 square inches/24 hours/atmospheric pressure,
Flexural modulus, 33700Kg/cm ² , ASTM heat distortion temperature 86°C at 18.6Kg/cm ² . C. Plaques outside the scope of this invention having the following properties were prepared by repeating step A using 100 parts by weight of a copolymer with an 80:20 ratio of acrylonitrile to styrene. :Oxygen permeation rate,
0.6 cc/mil/100 square inches/24 hours/atmospheric pressure, flexural modulus, 45000 Kg/cm ² , ASTM heat distortion temperature 93°C at 18.6 Kg/cm ² . Example 2 A blend was prepared by the procedure of Example 1A using 50 parts by weight of a copolymer with a 60:40 ratio of methyl methacrylate to styrene and 50 parts by weight of a copolymer with an 80:20 ratio of acrylonitrile to styrene. This blend has an oxygen transmission rate of 3.6 cc/mil/100 square inches/24 hours/atmospheric pressure and a flexural modulus of 40100.
Kg/cm ² , ASTM heat distortion temperature 88 at 18.6Kg/cm ²
It was warm at ℃. Example 3 A blend was prepared by the procedure of Example 1A using 15 parts by weight of a copolymer with a 60:40 ratio of methyl methacrylate to styrene and 85 parts by weight of a copolymer with an 80:20 ratio of acrylonitrile to styrene. This blend has an oxygen transmission rate of 1.0 cc/mil/100 square inches/24 hours/atmospheric pressure and a flexural modulus of 42200.
Kg/cm ² , ASTM heat distortion temperature 93 at 18.6Kg/cm ²
It was warm at ℃. Example 4 A Ratio of methyl methacrylate to styrene is 60:40
The procedure of Example 1A was repeated using 15 parts by weight of a copolymer of Ta. The resulting blend had the following properties: :Oxygen permeation rate, 1.9
cc/mil/100 square inches/24 hours/atmospheric pressure,
Flexural modulus, 38000Kg/cm ² , ASTM heat distortion temperature 92°C at 18.6Kg/cm ² . B. Using 100 parts of a rubber-modified acrylonitrile-styrene copolymer and no methyl methacrylate-styrene copolymer, a product outside the scope of this invention having the following properties was prepared by the procedure of Example A. Manufactured. : Oxygen transmission rate 3.0cc/mil/100 square inches/24 hours/atmospheric pressure, flexural modulus, 35100Kg/ ^cm2 , ASTM heat distortion temperature 90°C at 18.6Kg/ ^cm2 .

Claims (1)

[Scope of Claims] 1. A copolymer () consisting of 50 to 70 parts by weight of methyl methacrylate and 50 to 30 parts by weight of styrene.
60% by weight and below copolymers () 98-40% by weight
The copolymer () is a blend consisting of at least one nitrile having the structure R is hydrogen, a lower alkyl group having 1 to 4 carbon atoms, or a halogen.
100 parts by weight of a mixture of 50% by weight or more of (A) and 50% by weight or less of styrene (B) based on (A) + (B) is mixed with a conjugated diene monomer selected from the group consisting of butadiene, isoprene, etc. , optionally styrene, a nitrile monomer having the structure [Formula] (R is as described above), structure [Formula] (R ₁ is hydrogen, an alkyl group having 1 to 4 carbon atoms, or a halogen, and R ₂ is a carbon number 50-100% by weight of polymerized conjugated diene, 0 comonomer.
It is prepared by polymerization in the presence of 0 to 40 parts of rubbery polymer (C) containing ~50% by weight. 2. The blend of claim 1, wherein (A) is acrylonitrile. 3. The blend according to claim 2, wherein (C) is a butadiene-styrene rubber. 4. The blend according to claim 1, wherein (A) is 70 to 90% by weight and (B) is 10 to 30% by weight. 5. The blend of claim 4, wherein (A) is acrylonitrile. 6. The blend according to claim 5, wherein (C) is a butadiene-styrene rubber.