# US 4,397,988 A · Blends of p-methylstyrene polymer and diene-styrene or diene-(p-methylstyrene) block copolymers

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- Number: US 4,397,988 A
- Document ID: US4397988A
- Status: Granted
- Kind: A
- Application number: 06/370,773
- Filed: 1982-04-22
- Granted: 1983-08-09
- Earliest claimed: 1982-04-22
- Assignees: Mobil Oil Corporation
- Inventors: Anthony M. Sherman
- Web page: https://patentgrep.com/patent/US4397988A

## CPC

- C08L 25/16: Homopolymers or copolymers of alkyl-substituted styrenes
- C08L 53/02: of vinyl-aromatic monomers and conjugated dienes
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

Blends of conjugated diene-styrene or diene-(p-methylstyrene) block copolymers and polymers of p-methylstyrene. The blends exhibit excellent physical and optical properties.

## Claims

### Claim 1

A polymer blend comprising
A. 10 to 90 parts by weight of a polymer comprising polymerized methylstyrene isomers as its major constituent in which the methylstyrene isomers include at least 90% of the para isomer; and
B. 90 to 10 parts by weight of a block copolymer of a conjugated diene and either styrene or methyl styrene, but not both, which block copolymer is selected from the group consisting of
a block copolymer of greater than 40 to 60 weight % of a conjugated diene and from 40 to less than 60 weight % styrene;
a block copolymer of 10 to less than 20 weight % of a conjugated diene and from greater than 80 to 90 weight % styrene; and
a block copolymer of 10 to 60 weight % conjugated diene, and 40 to 90 weight % methylstyrene isomers having a para content of at least 90%.

### Claim 2

A polymer blend comprising
A. 10 to less than 40 parts by weight of a polymer comprising polymerized methylstyrene isomers as its major constituent in which the methylstyrene isomers include at least 90% of the para isomer;
and
B. 90 to greater than 60 parts by weight of a block copolymer of 10 to 60 weight % conjugated diene, and 40 to 90 weight % of either styrene or methylstyrene isomers, but not both, in which said methyl styrene isomers have a para content of at least 90%.

### Claim 3 (depends on 1)

The polymer blend of claim 1 having lower haze and higher optical transmission than the corresponding blend in which (A) is sytrene polymer.

### Claim 4 (depends on 1)

The polymer blend of claim 1 in which (B) is a block copolymer containing styrene.

### Claim 5 (depends on 1)

The polymer blend of claim 1 in which (B) is a block copolymer containing para-methylstyrene.

### Claim 6 (depends on 1)

The blend of claim 1 in which (A) is a polymer consisting of polymerized methylstyrene isomers.

### Claim 7 (depends on 1)

An article made by forming a sheet from the blend of claim 1 and thermoforming the article.

### Claim 8 (depends on 2)

The polymer blend of claim 2 having lower haze and higher optical transmission than the corresponding blend in which (A) is styrene polymer.

### Claim 9 (depends on 2)

The polymer blend of claim 2 in which (B) is a block copolymer containing styrene.

### Claim 10 (depends on 2)

The polymer blend of claim 2 in which (B) is a block copolymer containing para-methylstyrene.

### Claim 11 (depends on 2)

The blend of claim 2 in which (A) is a polymer consisting of polymerized methylstyrene isomers.

### Claim 12 (depends on 2)

An article made by forming a sheet from the blend of claim 2 and thermoforming the article.

### Claim 13

A polymer blend comprising
A. greater than 70 to 90 parts by weight of a polymer comprising polymerized methylstyrene isomers as its major constituent in which the methylstyrene isomers include at least 90% of the para isomer;
and
B. less than 30 to 10 parts by weight of a block copolymer of 10 to 60 weight % conjugated diene, and 40 to 90 weight % of either styrene or methylstyrene isomers, but not both, in which said methyl styrene isomers have a para content of at least 90%.

### Claim 14 (depends on 13)

The polymer blend of claim 13 having lower haze and higher optical transmission than the corresponding blend in which (A) is styrene polymer.

### Claim 15 (depends on 13)

The polymer blend of claim 13 in which (B) is a block copolymer containing styrene.

### Claim 16 (depends on 13)

The polymer blend of claim 13 in which (B) is a block copolymer containing para-methylstyrene.

### Claim 17 (depends on 13)

The blend of claim 13 in which (A) is a polymer consisting of polymerized methylstyrene isomers.

### Claim 18 (depends on 13)

An article made by forming a sheet from the blend of claim 13 and thermoforming the article.