# US 5,352,744 A · Method for hydrogenating polymers and products therefrom

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- Number: US 5,352,744 A
- Document ID: US5352744A
- Status: Granted
- Kind: A
- Application number: 08/031,460
- Filed: 1993-03-15
- Granted: 1994-10-04
- Earliest claimed: 1993-03-15
- Assignees: University of Minnesota
- Inventors: Frank S. Bates; Mark D. Gehlsen; Vincent L. Hughes; Patrick Brant
- Web page: https://patentgrep.com/patent/US5352744A

## CPC

- C08F 8/04: Reduction, e.g. hydrogenation
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS

## Abstract

This invention relates to a method for hydrogenation of poly(alkenyl aromatic) polymers or poly(alkenyl aromatic)/polydiene block copolymers that provides hydrogenated polymers with 99.5% or greater unsaturation and an MWD of less than about 3. Hydrogenated polymers and adhesives comprising the hydrogenated polymers and tackifier are also provided.

## Claims

### Claim 1

A method for hydrogenating poly(alkenyl aromatic) polymers and poly(alkenyl aromatic)/polydiene block copolymers to at least 99.5% saturation, said method comprising:
contacting under reaction conditions a poly(alkenyl aromatic) polymer or a poly(alkenyl aromatic)/polydiene block copolymer, said polymers having a Mw of 100,000 or more, with a metal catalyst on an alkali metal salt or alkaline earth metal salt.

### Claim 2 (depends on 1)

The method of claim 1 further comprising recovering a hydrogenated polymer having greater than 99.5% saturation and a Mw/Mn of less than about 3.

### Claim 3 (depends on 1)

The method of claim 1 wherein the poly(alkenyl aromatic) polymer or the poly(alkenyl aromatic) block is a polymer or copolymer of styrene, para-methyl styrene, methylstyrene, dimethylstyrene, para-dimethylstyrene, butyl-styrene, t-butyl-styrene, vinylxylene, ethylvinylxylene, isopropylstyrene, vinylnapthalene, or a mixture thereof.

### Claim 4 (depends on 1)

The method of claim 1, wherein the polydiene is a polymer of one or more conjugated dienes.

### Claim 5 (depends on 1)

The method of claim 1, wherein the polydiene is a polymer of one or more C.sub.4 to C.sub.20 dienes.

### Claim 6 (depends on 1)

The method of claim 1, wherein the polydiene is a polymer of one or more C.sub.4 to C.sub.10 dienes.

### Claim 7 (depends on 1)

The method of claim 1, wherein the polydiene is polyisoprene or polybutadiene.

### Claim 8 (depends on 1)

The method of claim 1, wherein the poly(alkenyl aromatic) polymer is syndiotactic.

### Claim 9 (depends on 8)

The method of claim 8, wherein the syndiotactic poly(alkenyl aromatic) polymer is syndiotactic polystyrene.

### Claim 10 (depends on 1)

The method of claim 1, wherein the catalyst metal is a transition metal.

### Claim 11 (depends on 1)

The method of claim 1, wherein the catalyst metal is gold, silver, platinum, palladium, rhenium, nickel, rhodium or chromium.

### Claim 12 (depends on 1)

The method of claim 1, wherein the support is a barium or calcium salt.

### Claim 13 (depends on 1)

The method of claim 1, wherein the support is BaSO.sub.4, CaCO.sub.3 or BaCO.sub.3.

### Claim 14 (depends on 2)

The method of claim 2, wherein the hydrogenated polymer has greater than about 99.75% saturation.