# US 5,348,990 A · Low dielectric materials

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- Number: US 5,348,990 A
- Document ID: US5348990A
- Status: Granted
- Kind: A
- Application number: 08/025,205
- Filed: 1993-03-02
- Granted: 1994-09-20
- Earliest claimed: 1993-03-02
- Assignees: Hoechst Celanese Corporation
- Inventors: Lakshaman M. Walpita; James B. Stamatoff; George Lundberg
- Web page: https://patentgrep.com/patent/US5348990A

## CPC

- C09K 19/00: Liquid crystal materials
- Y10T 428/3154: Of fluorinated addition polymer from unsaturated monomers
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A low dielectric material made of a liquid crystal polymer, polytetrafluoroethylene, and hollow glass spheres. This material is a relatively low cost, low dielectric blend having good physical strength and chemical and temperature resistance.

## Claims

### Claim 1

A low dielectric material comprising at least about 30% by weight of a liquid crystal polymer, at least about 10% by weight polytetrafluoroethylene, and at least about 5% by weight hollow glass spheres, wherein said material has dielectric constant in the approximate range of from 1.1 to 3.4.

### Claim 2 (depends on 1)

A low dielectric material according to claim 1 wherein said liquid crystal polymer comprises repeating units derived from 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid.

### Claim 3 (depends on 1)

A low dielectric material according to claim 1 wherein said liquid crystal polymer comprises from about 30 to about 60 percent by weight.

### Claim 4 (depends on 1)

A low dielectric material according to claim 1 wherein said hollow glass spheres comprise from about 5 to about 30 percent by weight.

### Claim 5 (depends on 1)

A low dielectric material according to claim 1 wherein said polytetrafluoroethylene comprises from about 10 to about 50 percent by weight.

### Claim 6

A low dielectric material comprising:
from about 30 to about 60 percent by weight of a liquid crystal polymer which comprises repeating units derived from 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid;
from about 10 to about 50 percent by weight of polytetrafluoroethylene; and,
from about 5 to about 40 percent by weight of hollow glass spheres.

### Claim 7 (depends on 6)

A low dielectric material according to claim 6 wherein said liquid crystal polymer comprises from about 40 to about 55 weight percent, said polytetrafluoroethylene comprises from about 15 to about 35 weight percent, and said hollow glass spheres comprise about 10 to about 30 weight percent of said material.

### Claim 8

A low dielectric material consisting essentially of:
from about 30 to about 60 percent by weight of a liquid crystal polymer which comprises repeating units derived from 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid;
from about 10 to about 50 percent by weight of polytetrafluoroethylene; and,
from about 5 to about 40 percent by weight of hollow glass spheres.

### Claim 9 (depends on 8)

A low dielectric material according to claim 8 in the form of a film.

### Claim 10 (depends on 9)

A film according to claim 9 having a thickness of from about 2 to about 200 mils.

### Claim 11 (depends on 9)

A film according to claim 9 having a thickness of from about 2 to about 100 mils.

### Claim 12 (depends on 9)

A film according to claim 9 having a thickness of from about 5 to about 40 mils.

### Claim 13 (depends on 1)

A process for making a low dielectric material according to claim 1 comprising the steps of:
blending together approximately 30-60 parts by weight of a liquid crystal polymer and about 5-40 parts by weight of hollow glass spheres at a temperature in the approximate range of 280.degree.-375.degree. C. to form a mixture; and,
subsequently blending about 10-50 parts by weight of polytetrafluoroethylene into said mixture at a temperature of about 280.degree.-375.degree. C.

### Claim 14 (depends on 13)

A process according to claim 13 wherein in each step said temperature is about 280.degree.-360.degree. C.

### Claim 15 (depends on 1)

A process for making a low dielectric material according to claim 1 comprising:
blending together approximately 30-60 parts by weight of a liquid crystal polymer, about 10-50 parts by weight of polytetrafluoroethylene, and about 5-40 parts by weight of hollow glass spheres at a temperature in the approximate range of 280.degree.-375.degree. C.

### Claim 16 (depends on 15)

A process according to claim 15 wherein said temperature is about 280.degree.-360.degree. C.

### Claim 17 (depends on 1)

A film comprising the composition of claim 1.

### Claim 18 (depends on 17)

A film according to claim 17 having a thickness of from about 2 to about 200 mils.

### Claim 19 (depends on 17)

A film according to claim 17 having a thickness of from about 2 to about 100 mils.

### Claim 20 (depends on 17)

A film according to claim 17 having a thickness of from about 5 to about 40 mils.