# US 10,870,757 B2 · Insulation, insulation precursors, and rocket motors, and related methods

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,870,757 B2
- Document ID: US10870757B2
- Status: Granted
- Kind: B2
- Application number: 16/045,352
- Filed: 2018-07-25
- Published: 2020-01-30
- Granted: 2020-12-22
- Earliest claimed: 2018-07-25
- Assignees: Northrop Grumman Innovation Systems, Inc.
- Applicants: Northrop Grumman Innovation Systems, Inc.
- Inventors: Benjamin W. C. Garcia; Robert S. Larson
- Web page: https://patentgrep.com/patent/US10870757B2

## CPC

- C08L 83/02: Polysilicates
- F02K 9/34: Casings; Combustion chambers; Liners thereof
- C08K 7/06: Elements
- C08K 7/28: Glass
- C09D 183/16: in which all the silicon atoms are connected by linkages other than oxygen atoms
- F02K 9/32: Constructional parts; Details not otherwise provided for
- C08G 77/60: in which all the silicon atoms are connected by linkages other than oxygen atoms
- C08J 5/042: {with carbon fibres}
- C08K 2201/005: Additives being defined by their particle size in general
- C09J 183/04: Polysiloxanes
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- 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)
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)

## Abstract

An insulation material includes a matrix comprising a reaction product formed from a silicon carbide precursor resin and a silicon dioxide precursor resin. At least one filler, such as hollow glass microspheres and/or carbon fiber is dispersed within the matrix. A rocket motor includes a case, the insulation material within and bonded to the case, and a solid propellant within the case. An insulation precursor includes a silicon carbide precursor resin, a silicon dioxide precursor resin, and the at least one filler. Related methods are also disclosed.

## Claims

### Claim 1

An insulation material, comprising:
a matrix comprising a reaction product formed from a silicon carbide precursor resin and a silicon dioxide precursor resin; and
at least one filler dispersed within the matrix, the at least one filler comprising at least one material selected from the group consisting of hollow glass microspheres, hollow polymeric microspheres, hollow ceramic microspheres, and hollow fibers.

### Claim 2 (depends on 1)

The insulation material of claim 1, wherein the matrix further comprises a catalyst.

### Claim 3 (depends on 1)

The insulation material of claim 1, wherein the insulation material exhibits a thermal conductivity of less than about 0.30 W/mK.

### Claim 4 (depends on 1)

The insulation material of claim 1, wherein the insulation material exhibits a density of less than about 0.8 g/cm3.

### Claim 5 (depends on 1)

The insulation material of claim 1, wherein the insulation material comprises from about 50% to about 85% silicon dioxide by weight.

### Claim 6 (depends on 1)

The insulation material of claim 1, wherein the at least one filler comprises the hollow glass microspheres.

### Claim 7 (depends on 6)

The insulation material of claim 6, wherein the insulation material comprises from about 5% to about 10% hollow glass microspheres by weight.

### Claim 8 (depends on 6)

The insulation material of claim 6, wherein the hollow glass microspheres exhibit a mean diameter from about 100 nm to about 5 mm.

### Claim 9 (depends on 1)

The insulation material of claim 1, wherein the at least one filler further comprises carbon fiber.

### Claim 10 (depends on 9)

The insulation material of claim 9, wherein the insulation material comprises from about 1% to about 5% carbon fiber by weight.

### Claim 11 (depends on 1)

The insulation material of claim 1, wherein the insulation material comprises from about 5% to about 10% silicon carbide by weight.

### Claim 12 (depends on 1)

The insulation material of claim 1, wherein the matrix comprises a reaction product formed from a silicon carbide precursor resin, a silicon dioxide precursor resin, and a crosslinking agent.

### Claim 13

A rocket motor, comprising:
a case;
an insulation material within the case, the insulation material comprising:
a matrix comprising a reaction product formed from a silicon carbide precursor resin and a silicon dioxide precursor resin; and
at least one filler dispersed within the matrix, the at least one filler comprising at least one material selected from the group consisting of hollow glass microspheres, hollow polymeric microspheres, hollow ceramic microspheres, and hollow fibers; and
a solid propellant within the case.

### Claim 14 (depends on 13)

The rocket motor of claim 13, further comprising a nozzle secured to the case.

### Claim 15 (depends on 13)

The rocket motor of claim 13, wherein the insulation material is bonded to the case with a silicone adhesive.

### Claim 16

A method of forming an insulation material, comprising:
combining a silicon carbide precursor resin, a silicon dioxide precursor resin, and at least one filler to form an insulation precursor, the at least one filler comprising at least one material selected from the group consisting of hollow glass microspheres, hollow polymeric microspheres, hollow ceramic microspheres, and hollow fibers; and
curing the insulation precursor to form an insulation material comprising the at least one filler dispersed within a solid matrix.

### Claim 17 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor, the silicon dioxide precursor resin, and the at least one filler, the silicon dioxide precursor resin comprising an organically modified silicon dioxide preceramic polymer.

### Claim 18 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor resin, the silicon dioxide precursor resin, the at least one filler, and a catalyst to form the insulation precursor.

### Claim 19 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor resin, the silicon dioxide precursor resin, the at least one filler, and an adhesion promoter to form the insulation precursor.

### Claim 20 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor resin, the silicon dioxide precursor resin, and the at least one filler, the silicon dioxide precursor resin exhibiting a density from about 0.95 g/cm3 to about 1.05 g/cm3.

### Claim 21 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor resin, the silicon dioxide precursor resin, and the at least one filler, the silicon carbide precursor resin exhibiting a density from about 1.10 g/cm3 to about 1.25 g/cm3.

### Claim 22 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor resin, the silicon dioxide precursor resin, the at least one filler, and a crosslinking agent to form the insulation precursor, the at least one filler comprising the hollow glass microspheres and carbon fiber, the insulation precursor comprising:
the silicon carbide precursor resin from about 5 weight % to about 10 weight %;
the silicon dioxide precursor resin from about 50 weight % to about 85 weight %;
the crosslinking agent from about 1 weight % to about 5 weight %;
the hollow glass microspheres from about 5 weight % to about 10 weight %; and
the carbon fiber from about 1 weight % to about 5 weight %.

### Claim 23 (depends on 16)

The method of claim 16, wherein the combining comprises combining the silicon carbide precursor resin, the silicon dioxide precursor resin, the at least one filler, a crosslinking agent, a catalyst, and an adhesion promoter to form the insulation precursor, the at least one filler comprising the hollow glass microspheres and carbon fiber, the insulation precursor consisting essentially of:
the silicon carbide precursor resin;
the silicon dioxide precursor resin;
the crosslinking agent;
the hollow glass microspheres;
the carbon fiber;
the catalyst; and
the adhesion promoter.

### Claim 24 (depends on 16)

The method of claim 16, wherein the combining to form the insulation precursor comprises forming the insulation precursor to exhibit a viscosity of less than about 100,000 cP at 25° C.

### Claim 25 (depends on 16)

The method of claim 16, wherein the combining to form the insulation precursor comprises forming the insulation precursor to exhibit a pot life of at least about 30 days at 25° C.

### Claim 26 (depends on 16)

The method of claim 16, wherein curing the insulation precursor comprises heating the insulation precursor to a temperature of at least about 150° C.

### Claim 27 (depends on 16)

The method of claim 16, wherein curing the insulation precursor comprises heating the insulation precursor to a temperature of at least about 250° C.

### Claim 28 (depends on 16)

The method of claim 16, further comprising heating the insulation material to a temperature of at least about 400° C.

### Claim 29

A method of insulating a rocket motor, comprising:
forming an insulation material, comprising:
combining a silicon carbide precursor resin, a silicon dioxide precursor resin, and at least one filler to form an insulation precursor, the at least one filler comprising at least one material selected from the group consisting of hollow glass microspheres, hollow polymeric microspheres, hollow ceramic microspheres, and hollow fibers; and
curing the insulation precursor to form the insulation material comprising the at least one filler dispersed within a solid matrix;
applying the insulation material to an interior surface of a case of a rocket motor; and
casting a propellant within the case.

### Claim 30 (depends on 29)

The method of claim 29, further comprising:
burning the propellant within the case; and
converting at least a portion of the solid matrix of the insulation material to a glassy solid while burning the propellant within the case.

### Claim 31 (depends on 29)

The method of claim 29, wherein applying the insulation material to an interior surface of a case of a rocket motor comprises bonding the insulation material to the interior surface of the case of the rocket motor.