One-part foamable latex composition
AssigneeGeneral Latex and Chemical Corporation
InventorsPerley A. Coffin, Philip G. Cook, Paul D. Demerjian
Life of this patent
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Abstract
A single-component foamable latex composition, the method of preparing the composition, and the foams prepared therefrom, which composition comprises a natural or synthetic latex or blends, ammonia, a curing system, a siloxane heat-sensitizing agent, and a zinc dibenzyl dithio carbamate accelerator. The latex composition is capable of being stored for a long period of time without gellation or precure prior to use. The combination of a heat-sensitizing agent and an ammonia-retardant accelerating agent has been found to prevent premature gellation and precure of the latex composition.
Claims27
A one-part foamable latex composition which may be stored for extended periods of time prior to foaming, which foamable latex composition comprises:
- a. a natural or synthetic elastomeric latex subject to cure;
- b. a curing system which comprises an ammonia-retardant dibenzyl dithiocarbamate accelerating agent, which agent is inhibited in accelerating function in the presence of the base;
- c. a volatile nitrogen-containing base in an amount sufficient to inhibit the cure of the latex;
- d. a siloxane heat-sensitizing agent to lower the coagulation temperature of the latex to about 90.degree.F or above;
- and
- e. a foaming agent in an amount to permit mechanical frothing of the composition into a foam.
A one-part foamable latex composition which may be stored for extended periods of time, which comprises in admixture;
- a. a natural or synthetic diene conjugated elastomeric latex or blends thereof;
- b. a curing system which comprises zinc dibenzyl dithio carbamate accelerator in an amount of from about 0.25 to 5.0 parts per hundred parts of the elastomer;
- c. an oxyalkylene-siloxane copolymeric heat-sensitizing agent in an amount of from about 1 to 15 parts per hundred parts of the elastomer;
- d. ammonia in an amount of from about 0.2 to 3.0 parts (dry weight theoretical basis) per hundred parts of the elastomer;
- and
- e. a foaming agent in an amount to permit mechanical frothing of the composition into a foam.
In a process for producing a latex composition, which latex composition comprises:
- a. a natural or synthetic elastomeric latex subject to cure;
- b. a curing system;
- and
- c. a base in an amount sufficient to inhibit the cure of the latex, the improvement which comprises:
- i. incorporating into the latex composition a siloxane heat-sensitizing agent to lower the coagulation temperature of the latex to about 90.degree.F or above;
- ii. incorporating a dibenzyl dithiocarbamate accelerating agent into the latex, which agent is inhibited in an accelerating function in the presence of the base;
- and
- iii. incorporating into the latex a foaming agent to permit mechanical frothing of the latex into a foam, thereby providing a one-part foamable latex composition which may be stored for extended periods of time prior to foaming and use.
In a process for producing a foamable latex composition, which latex composition comprises:
- a. a natural or synthetic elastomeric latex subject to cure;
- b. a curing system;
- c. ammonia in an amount of from about 0.2 to 3.0 parts (dry weight theoretical basis) per hundred parts of the elastomer;
- and
- d. a foaming agent;
- the improvement which comprises:
- i. incorporating into the foamable latex composition from about 1 to 15 parts per hundred parts of elastomer of a siloxane heat-sensitizing agent to lower the coagulation temperature to a range of from about 100.degree. to 180.degree.F;
- and
- ii. incorporating into the latex composition from about 0.25 to 5.0 parts per hundred parts of the elastomer of a zinc dibenzyl dithio carbamate accelerator, thereby providing a one-part latex composition with reduced precure and gellation tendencies during extended periods of storage.
Dependencies are inferred from the claim text.