Thermoplastic workholding composition and method of holding a workpiece

Claim 2

A normally solid thermoplastic hot melt composition comprising a dispersion of from 5% to 70% by weight of an inorganic moiety which is a finely divided inorganic filler having a particle size such that 95% passes through a 200 mesh Standard screen and from 95% to 30% by weight of an organic moiety which is a blend of: (a) 5 to 20 parts by weight of an aliphatic dicarboxylic acid containing from 32 to 40 carbon atoms; (b) From 10 to about 20 parts by weight of a C 5 -C 6 alkylene hydrocarbon polymer having a molecular weight in the range of from about 1000 to about 1400; and (c) 10 to 20 parts by weight of a nonpolar aromatic hydrocarbon polymer having a softening point in the range of from about 98° to 115° C. measured by the ring and ball method; the amount of said inorganic filler on a volume basis being less than the CPVC of the inorganic filler in said organic moiety.

Claim 3

A composition in accordance with claim 1 wherein the aliphatic dibasic carboxylic acid is a dimeric fatty acid of an unsaturated monocarboxylic fatty acid containing from 16-20 carbon atoms.

Claim 4

A composition in accordance with claim 2 wherein the unsaturated monocarboxylic fatty acid is linoleic.

Claim 5

A composition in accordance with claim 1 wherein the alkylene hydrocarbon polymer is one having a molecular weight of 1200 and a softening point of about 100° C. as determined by the ring and ball method.

Claim 6

A composition in accordance with claim 4 wherein the alkylene hydrocarbon polymer is a polyterpene.

Claim 7

A composition in accordance with claim 5 wherein the polyterpene is a polymer of the following mixture of alkylene hydrocarbons: ______________________________________ 2-pentene 4.8% 2-methyl-2-butene 42.2% Isoprene 2.5% 1,3-pentadiene 42.4% 2,3-dimethyl-1-butene 2.3% Unsat. C.sub.5 --C.sub.6 hydrocarbons 5.7% ______________________________________

Claim 8

A composition in accordance with claim 1 wherein the nonpolar aromatic hydrocarbon polymer is one having a softening point in the range of 98-102, an acid number less than 1 and a saponification value less than 1.

Claim 9

A composition in accordance with claim 1 wherein the inorganic filler material is a ceramic oxide.

Claim 10

A composition in accordance with claim 8 wherein the ceramic oxide is aluminum oxide.

Claim 11

A composition in accordance with claim 8 wherein the aluminum oxide has a particle size such that at least 95% passes through a 325 mesh screen.

Claim 12

A composition in accordance with claim 1 wherein the aliphatic dicarboxylic acid is dilinoleic acid in an amount of from 5 to 10 parts by weight; the C 5 -C 6 alkylene hydrocarbon polymer is a polymer of the following mixture of alkylene hydrocarbons: ______________________________________ 2-pentene 4.8% 2-methyl-2-butene 42.2% Isoprene 2.5% 1,3-pentadiene 42.4% 2,3-dimethyl-1-butene 2.3% ______________________________________ having a molecular weight of 1200 and present in an amount of from 12 to 14 parts by weight; the nonpolar aromatic hydrocarbon polymer has a softening point in the range of 98-102, an acid number less than 1, and a saponification number less than 1 and is present in an amount of about 13 parts by weight; and from 60% to 68% by weight of powdered aluminum oxide having a particle size such that at least 95% passes through a 325 mesh screen.

Claim 13

In the process of holding a workpiece in a workholder, the steps of: (a) positioning the workpiece in the workholder; (b) heating to a liquid state a normally solid thermoplastic workholding composition comprising a dispersion of from 5% to 70% by weight of an inorganic moiety which is a finely divided inorganic filler having a particle size such that 95% passes through a 200 mesh standard screen, in from 95% to 30% by weight of an organic moiety which is a physical melt blend of: (1) 5 to 20 parts by weight of an aliphatic dicarboxylic acid containing from 32 to 40 carbon atoms; (2) From about 10 to 20 parts by weight of a C 5 -C 6 alkylene hydrocarbon polymer having a molecular weight in the range of from about 1000 to 1400; and (3) 10 to 20 parts by weight of a nonpolar aromatic hydrocarbon polymer having a softening point in the range of from about 98° to 115° C. measured by the ring and ball method; (c) introducing said composition while at a temperature of from 250° to about 300° F. into said workholder to surround said workpiece; (d) quenching said workholder, workpiece and said workholding composition to a solidification temperature with cold water.

Claim 14

In the process of holding a workpiece in a workholder, the steps of: (a) positioning the workpiece in the workholder; (b) heating to a liquid state a normally solid thermoplastic workholding composition comprising a dispersion of from 5% to 70% by weight of an inorganic moiety which is a finely divided inorganic filler having a particle size such that 95% passes through a 200 mesh standard screen, in from 95% to 30% by weight of an organic moiety which is a physical melt blend of: (1) 5 to 20 parts by weight of an aliphatic dicarboxylic acid containing from 32 to 40 carbon atoms; (2) From about 10 to 20 parts by weight of a C 5 -C 6 alkylene hydrocarbon polymer having a molecular weight in the range of from about 1000 to 1400; and (3) 10 to 20 parts by weight of a nonpolar aromatic hydrocarbon polymer having a softening point in the range of from about 98° to 115° C. measured by the ring and ball method; (c) introducing said composition while at a temperature of from 250° to about 300° F. into said workholder to surround said workpiece; (d) quenching said workholder, workpiece and said workholding composition to a solidification temperature with cold water.

Claim 15

A process in accordance with claim 12 wherein the alkylene hydrocarbon polymer is one having a molecular weight of 1200 and a softening point of about 100° C. as determined by the ring and ball method.

Claim 16

A process in accordance with claim 13 wherein the alkylene hydrocarbon polymer is a polyterpene.

Claim 17

A process in accordance with claim 14 wherein the polyterpene is a polymer of the following mixture of alkylene hydrocarbons: ______________________________________ 2-pentene 4.8% 2-methyl-2-butene 42.2% Isoprene 2.5% 1,3-pentadiene 42.4% 2,3-dimethyl-1-butene 2.3% Unsat. C.sub.5 --C.sub.6 hydrocarbons 5.7% ______________________________________

Claim 18

A normally solid thermoplastic resin base formed by blending at a temperature above 200° F. (a) 5 to 20 parts by weight of an aliphatic dicarboxylic acid containing from 32 to 40 carbon atoms; (b) From 10 to about 20 parts by weight of a C 5 -C 6 alkylene hydrocarbon polymer having a molecular weight in the range of from about 1000 to about 1400; and (c) 10 to 20 parts by weight of a nonpolar aromatic hydrocarbon polymer having a softening point in the range of from about 98° to 115° C. measured by the ring and ball method.

Claim 19

A normally solid thermoplastic resin base formed by blending at a temperature above 200° F. (a) 5 to 20 parts by weight of an aliphatic dicarboxylic acid containing from 32 to 40 carbon atoms; (b) From 10 to about 20 parts by weight of a C 5 -C 6 alkylene hydrocarbon polymer having a molecular weight in the range of from about 1000 to about 1400; and (c) 10 to 20 parts by weight of a nonpolar aromatic hydrocarbon polymer having a softening point in the range of from about 98° to 115° C. measured by the ring and ball method.

Claim 20

A composition in accordance with claim 16 wherein the aliphatic dibasic carboxylic acid is a dimeric fatty acid of an unsaturated monocarboxylic fatty acid containing from 16-20 carbon atoms.

Claim 21

A composition in accordance with claim 17 wherein the unsaturated monocarboxylic fatty acid is linoleic.

Claim 22

A composition in accordance with claim 16 wherein the nonpolar aromatic hydrocarbon polymer is one having a softening point in the range of 98-102, an acid number less than 1 and a saponification value less than 1.