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US 11,021,567 B2Granted
Polyols for improved viscoelastic foams with reduced temperature sensitivity
AssigneeCovestro LLC
InventorsNigel Barksby, Brian L. Neal, Susan B. McVey, John E. Hayes
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Abstract
This invention relates to a process for preparing viscoelastic polyurethane foam in which the isocyanate-reactive component comprises a specific polyol blend, and to viscoelastic polyurethane foam wherein the isocyanate-reactive comprises the specific polyol blend. The polyol blend may be an in situ formed polyol blend.
Claims21
A process for preparing a viscoelastic polyurethane foam comprising reacting:
- (1) toluene diisocyanate,
- with
- (2) an isocyanate-reactive component comprising:
- (a) a polyol blend having an overall hydroxyl number of from 70 mg KOH/g polyol to 110 mg KOH/g polyol, an average functionality of greater than 2, and comprising:
- (i) a monofunctional polyether having a hydroxyl number of less than or equal to 56 mg KOH/g polyol, and containing less than or equal to 20% of copolymerized oxyethylene, based on the total weight of the monofunctional polyether (2)(a)(i);
- (ii) a polyether polyol having a hydroxyl number of from 80 mg KOH/g polyol to 300 mg KOH/g polyol, a nominal functionality of 2, and containing from 5 to 45% of copolymerized oxyethylene, based on the total weight of said polyether polyol (2)(a)(ii);
- and
- (iii) a polyether polyol having a hydroxyl number of from 80 mg KOH/g polyol to 300 mg KOH/g polyol, a nominal functionality of greater than 2 to 8, and containing from 5 to 45% of copolymerized oxyethylene, based on the total weight of said polyether polyol (2)(a)(iii);
- wherein (2)(a) said polyol blend comprises 20 to 50% by weight of (2)(a)(i) said monofunctional polyether and 80 to 50% by weight of components (2)(a)(ii) and (2)(a)(iii) wherein component (2)(a)(ii) is provided in an amount of 10 to 90% by weight and component (2)(a)(iii) is provided in an amount of 90 to 10% by weight, based on the total combined weight of components (2)(a)(ii) and (2)(a)(iii);
- and, optionally,
- (b) a polyether polyol having an average functionality of from 2 to 8, a hydroxyl number of from 20 mg KOH/g polyol to 300 mg KOH/g polyol and containing at least 50% of copolymerized oxyethylene, based on the total weight of said polyether polyol (2)(b);
- wherein (2) the isocyanate-reactive component comprises (2)(a) said polyol blend in an amount of from 20% to 100% by weight and (2)(b) said polyether polyol in an amount of up to 80% by weight, with the combined weight of (2)(a) and (2)(b) totalling 100% by weight;
- in the presence of
- (3) a blowing agent;
- (4) a catalyst;
- and
- (5) a surfactant;
- wherein the quantity, OH number and functionality of components (2)(a)(i), (2)(a)(ii) and (2)(a)(iii) are selected such that the resultant viscoelastic foam has a ratio of the storage modulus ratio at 15° C. to the storage modulus at 30° C. of less than or equal to 4 to about 1, and wherein the resultant viscoelastic foam has a Tg of less than 20° C. as measured by tan delta over a density range of from 1.0 lb/ft3 to 6.0 lb/ft3 at an NCO Index of greater than 95 to 110, with the proviso that when the NCO Index is greater than or equal to about 105, the isocyanate-reactive component (2) comprises at least about 3% by weight of (2)(b).
15 more elements
A viscoelastic polyurethane foam comprising the reaction product of:
- (1) toluene diisocyanate,
- with
- (2) an isocyanate-reactive component comprising:
- (a) a polyol blend having an overall hydroxyl number of from 70 mg KOH/g polyol to 110 mg KOH/g polyol, an average functionality of greater than 2, and comprising:
- (i) a monofunctional polyether having a hydroxyl number of less than or equal to 56 mg KOH/g polyol, and containing less than or equal to 20% of copolymerized oxyethylene, based on the total weight of said monofunctional polyether (2)(a)(i);
- (ii) a polyether polyol having a hydroxyl number of from 80 mg KOH/g polyol to 300 mg KOH/g polyol, a nominal functionality of 2, and containing from 5 to 45% of copolymerized oxyethylene, based on the total weight of said polyether polyol (2)(a)(ii);
- and
- (iii) a polyether polyol having a hydroxyl number of from 80 mg KOH/g polyol to 300 mg KOH/g polyol, a nominal functionality of greater than 2 to 8, and containing from 5 to 45% of copolymerized oxyethylene, based on the total weight of said polyether polyol (2)(a)(iii);
- wherein (2)(a) said polyol blend comprises 20 to 50% by weight of (2)(a)(i) said monofunctional polyether and 80 to 50% by weight of components (2)(a)(ii) and (2)(a)(iii) wherein component (2)(a)(ii) is provided in an amount of 10 to 90% by weight and component (2)(a)(iii) is provided in an amount of 90 to 10% by weight, based on the total combined weight of components (2)(a)(ii) and (2)(a)(iii);
- and, optionally,
- (b) a polyether polyol having an average functionality of from 2 to 8, a hydroxyl number of from 20 mg KOH/g polyol to 300 mg KOH/g polyol and containing at least 50% of copolymerized oxyethylene, based on the total weight of said polyether polyol (2)(b);
- wherein (2) the isocyanate-reactive component comprises (2)(a) said polyol blend in an amount of from 20% to 100% by weight and (2)(b) said polyether polyol in an amount of up to 80% by weight, with the combined weight of (2)(a) and (2)(b) totaling 100% by weight;
- in the presence of
- (3) a blowing agent;
- (4) a catalyst;
- and
- (5) a surfactant;
- wherein the quantity, OH number and functionality of components (2)(a)(i), (2)(a)(ii) and (2)(a)(iii) are selected such that the resultant viscoelastic foam has a ratio of the storage modulus at 15° C. to the storage modulus at 30° C. of less than or equal to 4 to 1, and wherein the resultant viscoelastic foam has a Tg of less than 20° C. as measured by tan delta over a density range of from 1.0 lb/ft3 to 6.0 lb/ft3 at an NCO Index of greater than 95 to 110, with the proviso that when the NCO Index is greater than or equal to about 105, the isocyanate-reactive component (2) comprises at least about 3% by weight of (2)(b).
15 more elements
Dependencies are inferred from the claim text.