US4810395A — Thixotropic grease composition

Claim 1

Independent Claim 257 words

A thixotropic grease composition having low critical yield stress, the composition comprising (a) 77 to 95% by weight (b.w.) of oil, or mixture of oils, selected from the class consisting of (i) ASTM type 103, 1040A, or 104B paraffinic or naphthenic oil having a minimum specific gravity of about 0.86 and a pour point (ASTM D97) of less than -4° C. (ii) polybutene oil of minimum specific gravity of about 0.83 and a pour point (ASTM D97) of less than 18° C., (iii) triglyceride-based vegetable oil, (iv) polypropylene oil, (v) chlorinated paraffin oil having a chlorine content between 30 and 75% b.w. and a viscosity at 25° C. of between 100 and 10,000 cps, and (vi) polymerized esters; (b) 2 to 15% b.w. colloidal particles selected from the group consisting of hydrophobic fumed silica, precipitated silica, and clay, the colloidal particles having a BET surface are in the range from about 50 to about 400 m 2 /g; and (c) up to 15% b.w. of bleed inhibitors selected from the group consisting of styrene-rubber and styrene-rubber-styrene block copolymers having a styrene/rubber ratio between about 0.1 and about 0.8, semiliquid rubber having a Flory molecular weight between 20,000 and 70,000, butyl rubber, ethylene-propylene rubber, ethylene-propylene dimer rubber, chlorinated butyl rubber having a Mooney viscosity at 100° C. (ASTM D-1646) between about 20 and 90, and depolymerized rubber having a viscosity at 38° C. between about 40,000 and 400,000 cps; with the foregoing ingredients (a), (b), and (c) making up at least 99% b.w. of the composition of matter.

Claim 2

Dependent Claim 257 words

A thixotropic grease composition having low critical yield stress, the composition comprising (a) 77 to 95% by weight (b.w.) of oil, or mixture of oils, selected from the class consisting of (i) ASTM type 103, 1040A, or 104B paraffinic or naphthenic oil having a minimum specific gravity of about 0.86 and a pour point (ASTM D97) of less than -4° C. (ii) polybutene oil of minimum specific gravity of about 0.83 and a pour point (ASTM D97) of less than 18° C., (iii) triglyceride-based vegetable oil, (iv) polypropylene oil, (v) chlorinated paraffin oil having a chlorine content between 30 and 75% b.w. and a viscosity at 25° C. of between 100 and 10,000 cps, and (vi) polymerized esters; (b) 2 to 15% b.w. colloidal particles selected from the group consisting of hydrophobic fumed silica, precipitated silica, and clay, the colloidal particles having a BET surface are in the range from about 50 to about 400 m 2 /g; and (c) up to 15% b.w. of bleed inhibitors selected from the group consisting of styrene-rubber and styrene-rubber-styrene block copolymers having a styrene/rubber ratio between about 0.1 and about 0.8, semiliquid rubber having a Flory molecular weight between 20,000 and 70,000, butyl rubber, ethylene-propylene rubber, ethylene-propylene dimer rubber, chlorinated butyl rubber having a Mooney viscosity at 100° C. (ASTM D-1646) between about 20 and 90, and depolymerized rubber having a viscosity at 38° C. between about 40,000 and 400,000 cps; with the foregoing ingredients (a), (b), and (c) making up at least 99% b.w. of the composition of matter.

Claim 3

Dependent Claim 73 words

Composition of claim 1, wherein at least 95% b.w. of the oil consists of oil selected from the group consisting of ASTM type 103, 104A, and 104B oils and polybutene oils, the colloidal particles consist essentially of particles selected from the group consisting of hydrophobic fumed silica nd hydrophilic fumed silica, and the bleed inhibitor consists essentially of inhibitors selected from the group consisting of styrene-rubber and styrene-rubber-styrene block copolymers, and semiliquid rubber.

Claim 4

Dependent Claim 34 words

Composition of claim 2, comprising between about 90 and about 95% b.w. oil, and between about 0.5 and about 5% b.w. bleed inhibitor, the bleed inhibitor consisting essentially of styrene-rubber or styrene-rubber-styrene block copolymer.

Claim 5

Dependent Claim 31 words

Composition of claim 2, comprising between about 77 and about 91% b.w. oil, and between about 3 and about 15% b.w. bleed inhibitor, the bleed inhibitor consisting essentially of semiliquid rubber.

Claim 6

Dependent Claim 15 words

Composition of claim 2, comprising between about 2 and about 10% b.w. of colloidal particles.

Claim 7

Dependent Claim 21 words

Composition of claim 1, wherein the composition has a critical yield stress that is less about 140 Pa at 20° C.

Claim 8

Dependent Claim 22 words

Composition of claim 6, wherein the composition has a critical yield stress that is less than about 70 Pa at 20° C.

Claim 9

Dependent Claim 80 words

Composition of claim 7, the composition comprising (a) between about 90 and about 95% b.w. oil selected from the group consisting of ASTM type 103, 104A, and 104B oil, and polybutene oil; (b) between about 2 and about 10% b.w. of colloidal particles selected from the group consisting of hydrophobic fused silica and hydrophilic fused silica; and (c) between about 0.5 and about 5% b.w. bleed inhibitor selected from the groups consisting of styrene-rubber block copolymer and styrene-rubber-styrene block copolymer.

Claim 10

Dependent Claim 170 words

A thixotropic grease composition comprising (a) 77 to 95% by weight (b.w.) of oil, or mixture of oils, selected from the group consisting of (i) ASTM type 103, 104A, or 104B paraffinic or naphthenic oil having a minimum specific gravity of about 0.86 and a pour point (ASTM D97) of less than -4° C, (ii) polybutene oil of minimum specific gravity of about 0.83 and a pour point (ASTM D97) of less than 18° C., (iii) triglyceride-based vegetable oil, (iv) polypropylene oil, (v) chlorinated paraffin oil having a chlorine content between 30 and 75% b.w. and a viscosity at 25° C. of between about 100 and 10,000 cps, and (vi) polymerized esters; (b) 2 to 15% b.w. colloidal particles selected from the group consisting of hydrophobic fumed silica, hydrophilic fumed silica, precipitated silica, and clay, the colloidal particles having a BET surface area in the range from about 50 to about 400 m 2 /g; the composition having a critical yield stress of at most 70 Pa at 20° C.

Claim 11

Dependent Claim 170 words

A thixotropic grease composition comprising (a) 77 to 95% by weight (b.w.) of oil, or mixture of oils, selected from the group consisting of (i) ASTM type 103, 104A, or 104B paraffinic or naphthenic oil having a minimum specific gravity of about 0.86 and a pour point (ASTM D97) of less than -4° C, (ii) polybutene oil of minimum specific gravity of about 0.83 and a pour point (ASTM D97) of less than 18° C., (iii) triglyceride-based vegetable oil, (iv) polypropylene oil, (v) chlorinated paraffin oil having a chlorine content between 30 and 75% b.w. and a viscosity at 25° C. of between about 100 and 10,000 cps, and (vi) polymerized esters; (b) 2 to 15% b.w. colloidal particles selected from the group consisting of hydrophobic fumed silica, hydrophilic fumed silica, precipitated silica, and clay, the colloidal particles having a BET surface area in the range from about 50 to about 400 m 2 /g; the composition having a critical yield stress of at most 70 Pa at 20° C.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1992-03-06	1992-09-05	1993-03-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1996-03-06	1996-09-05	1997-03-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2000-03-06	2000-09-05	2001-03-07	$7700.00	Window Closed / Lapsed

Thixotropic grease composition

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