# US 5,707,734 A · Glass fibers having fumed silica coating

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- Number: US 5,707,734 A
- Document ID: US5707734A
- Status: Granted
- Kind: A
- Application number: 08/459,956
- Filed: 1995-06-02
- Granted: 1998-01-13
- Earliest claimed: 1995-06-02
- Assignees: Owens Corning Fiberglas Technology, Inc.
- Inventors: Christopher M. Hawkins; Robert A. Schweizer
- Web page: https://patentgrep.com/patent/US5707734A

## CPC

- C08K 9/02: Ingredients treated with inorganic substances
- C03C 25/42: Coatings containing inorganic materials
- C03C 25/47: containing particles, fibres or flakes, e.g. in a continuous phase
- C08J 5/06: using pretreated fibrous materials
- C09K 21/14: Macromolecular materials
- Y10T 428/2927: including structurally defined particulate matter
- Y10T 428/2933: Coated or with bond, impregnation or core
- Y10T 428/2938: Coating on discrete and individual rods, strands or filaments
- Y10T 428/2964: Artificial fiber or filament
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A composite having enhanced flame retardant behavior includes a polymer and glass fibers coated with fumed silica. The composite can be based on a wide variety of polymers such as polybutylene and polyethylene terephthalates, polycarbonates, polyethylenes, polypropylenes and nylons. The glass fibers are also preferably coated with fibrillar polytetrafluoroethylene.

## Claims

### Claim 1

A flame-retardant fiber-reinforced composite comprising:
a matrix material comprising a polymer; and
glass fibers having a coating comprising fumed silica thereon forming coated glass fibers, wherein the glass fibers have an average length between about 3 mm and about 130 mm and an average diameter between about 7 microns and about 25 microns.

### Claim 2 (depends on 1)

A composite according to claim 1, wherein said coated glass fibers are present in said composite in an amount of from about 10% to about 50% by weight of the composite.

### Claim 3 (depends on 1)

A composite according to claim 1, wherein said fumed silica is coated on said glass fibers in an amount of from about 0.5% to about 10% by weight of the glass fibers.

### Claim 4 (depends on 1)

A composite according to claim 1, further comprising fibrillar polytetrafluoroethylene in an amount of from about 0.01% to about 5% by weight of the composite.

### Claim 5 (depends on 1)

A composite according to claim 1, wherein said coating further comprises fibrillar polytetrafluoroethylene.

### Claim 6 (depends on 1)

A composite according to claim 1, wherein said polymer is a thermoplastic resin.

### Claim 7 (depends on 1)

A composite according to claim 1, wherein said polymer is selected from the group consisting of polybutylene and polyethylene terephthalates, polycarbonates, polyethylenes, polypropylenes, nylons, and mixtures thereof.

### Claim 8 (depends on 1)

A composite according to claim 1, wherein said polymer is present in an amount of from about 40% to about 90% by weight of the composite.

### Claim 9 (depends on 1)

A composite according to claim 1, wherein said average length of the glass fibers is between about 3 mm and about 25 mm.

### Claim 10 (depends on 1)

A composite according to claim 1, wherein said fumed silica has an average particle size of up to 10 microns.

### Claim 11 (depends on 10)

A composite according to claim 10, wherein said coated glass fibers are present in an amount of from about 20% to about 40% by weight of the composite.

### Claim 12 (depends on 1)

A composite according to claim 1, wherein said fumed silica has been treated with octamethylcyclotetrasiloxane and hexamethyldisilazane.

### Claim 13

A flame-retardant fiber-reinforced composite comprising from about 65% to about 75% by weight polybutylene terephthalate as a matrix material and from about 25% to to about 35% by weight of coated glass fibers, said coated glass fibers comprising fibers of a glass material and a coating thereon comprising fumed silica and fibrillar polytetrafluoroethylene, wherein the fibers have an average length between about 3 mm and about 6 mm and an average diameter between about 10 microns and about 14 microns, the timed silica is present in an amount of from about 1% to about 6% by weight of the fibers, and the fibrillar polytetrafluoroethylene is present in an amount of from about 0.05% to about 1% by weight of the composite.