US 4,843,114 A · Rubber compound for tracked vehicle track pads

Abstract

A highly improved elastomeric composition, process, and articles made thef, wherein the novel composition is characterized by greatly increased wear longevity, thermomechanical stability, highly improved tear and tensile strength at high temperature useage, in addition to high resistance to burning in open flame, as well as high resistance to cutting, chipping, cracking and crack propagation particularly in product use for tank track pads and other related track system elastomeric component products; wherein the improved composition is a unique combination of its respective polymer, filler, curing and antidegradant systems, in which the polymer system either consists of about 100 parts by weight of highly saturated nitrile polymer or of various novel blends of the highly saturated nitrile usually in majority amounts together with minority amounts of carboxylated nitrile, with or without additional minority or near equal parts of nitrile rubber; and wherein the curing system may include various blends of from between about 1.5 to about 30 parts by weight of a metallic oxide, along with from between about 25 to about 50 parts by weight of a metallic methyl-methacrylate resin, together with from about 0.25 to about 3 parts by weight of a curative compound; which composition is further well suited for manufacture of various abutment and motion stop or limit members subjectable to repetitive engagement by moving mechanisms, and for various at least semi-flexible baffle or skirt-like members useable with various air cushion type vehicles or the like.

Claims25

Dependent claims

An improved vulcanizable elastomeric composition that has a unique combination of respective polymer, filler, curing, and antidegradant systems, comprising:

A. said polymer system is selected from the group consisting of
(a) about 100 parts by weight of highly saturated nitrile polymer having a degree of unsaturation ranging between about 1% to about 20%;
(b) a blend of from about 80 to about 90 parts by weight of highly saturated nitrile polymer having a degree of unsaturation ranging between about 1% to about 20%, and of from about 10 to about 20 parts by weight of carboxylated nitrile;
and
(c) a blend of from about 45 to about 90 parts of highly saturated nitrile polymer having a degree of unsaturation ranging between about 1% to about 20%, and of from about 1 to a maximum of about 5 parts of carboxylated nitrile polymer, and of from about 5 to about 50 parts of nitrile rubber;
and
B. said curing system comprising
(a) from about 1.5 to about 30 parts by weight of a metallic oxide selected from the group consisting of zinc oxide and magnesium oxide;
(b) from about 25 to about 50 parts by weight of a metallic methylmethacrylate resin selected from the group consisting of at least a zinc methyl-methacrylate resin and a zinc dimethyl-methacrylate resin;
(c) a curative compound of from about 0.25 parts to about 3 parts selected from the group consisting of:
(i) dicumyl peroxide,
(ii) derivatives of dicumyl peroxide;
(iii) sulfur, and
(iv) sulfur donor chemicals.

11 more elements

A process for preparation of a vulcanizable elastomeric composition, said process comprising the steps of:

I. blending a mixture of
A. about 100 parts by weight of highly saturated nitrile polymer where the degree of unsaturation ranges from about 1% to about 20%;
B. from about 15 to about 25 parts by weight of a highly reinforcing filler,
C. a curative mixture comprising
(a) from about 1.5 to about 30 parts by weight of a metallic oxide selected from the group consisting of zinc oxide and magnesium oxide
(b) from about 20 to about 50 parts by weight of a metallic methymethacrylate resin selected from the group consisting of a zinc methyl-methacrylate resin and a zinc dimethyl-methacrylate resin;
(c) a curative compound of from about 0.25 parts to about 3 parts selected from the group consisting of:
(i) dicumyl peroxide,
(ii) derivatives of dicumyl peroxide;
(iii) sulfur, and
(iv) sulfur donor chemicals;
and
D. an antidegradant mixture comprising from about 0.25 to about 2 parts by weight of an antioxidant selected from the group consisting of the antioxidants from the respective families of
(a) quinolines,
(b) substituted para-phenylenediamine (PPD), and
(c) hindered bisphenols;
and
II. recovering said mixture formed in step I.

15 more elements

Dependencies are inferred from the claim text.

Rubber compound for tracked vehicle track pads

Life of this patent

Rubber compound for tracked vehicle track pads

Life of this patent

Abstract

Claims25