US 4,559,366 AGranted

Preparation of microcellular polyurethane elastomers

AssigneeJaquelyn P. Pirri

InventorFritz Hostettler

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Abstract

There are provided improved integral skin microcellular polyether polyurethane elastomer products, e.g., shoe soles, which are characterized by outstanding low temperature dynamic flex and green strength at demold, at specific gravities as low as about 0.4 gm/cc. These elastomer products are desirably prepared from a two-component system, e.g., the reaction of Component A containing improved quasi-prepolymers, with Component B comprising a compatible liquid mixture containing poly(oxyethyleneoxypropylene)polyol, difunctional chain extender, halogenated blowing agent and other ingredients, as needed, over a relatively wide isocyanate index range without the drawback of any significant loss in the elastomer properties due to index fluctuation within said range. Improved integral skin microcellular polyether elastomers of low densities, e.g., 0.45 gm/cc, characterized by an excellent smooth surface appearance essentially devoid of blemishes can also be prepared from such two-package systems without the use of water as a secondary blowing agent. The said quasi-prepolymers are normally-liquid, may have crystalline points as low as -20.degree. C., and are derived from the reaction of (1) a mixture of normally solid diphenylmethane diisocyanate, carbodiimide and/or uretone imine and (2) poly(oxyethyleneoxypropylene)polyols.

Claims41

Dependent claims

An integral skin microcellular polyether polyurethane elastomer product having a specific gravity in the range approximating about 0.4 to about 0.7 gm/cm.sup.3 produced by reacting a formulation comprising:

(a) liquid quasi-polyoxyethyleneoxypropylene prepolymers having a crystalline point below about 13.degree. C. resulting from the reaction of (1) a mixture consisting essentially of (i) a normally-solid diphenylmethane diisocyanate and (ii) the carbodiimide of diphenylmethane diisocyanate and/or the uretone imine of diphenylmethane diisocyanate, or (iii) the carbodiimide of tolylene diisocyanate and/or the uretone imine of tolylene diisocyanate;
with (2) an ethylene oxide capped polyol of the group consisting of poly(oxyethyleneoxypropylene)polyols and polymer/poly(oxyethyleneoxypropylene)polyols and mixtures thereof, said ethylene oxide capped polyol having a hydroxyl equivalent weight of about 750 to about 3000, a hydroxyl functionality of 2 to 3, an oxyethylene cap of about 10 to about 30% by weight, and an internal oxyethylene content of from about 0 to 40% by weight, the total oxyethylene content of said capped polyol not exceeding about 50% by weight, the remainder of the capped polyol consisting essentially of oxypropylene;
(b) an ethylene oxide capped polyol of the group consisting of poly(oxyethyleneoxypropylene)polyols and polymer/poly(oxyethyleneoxypropylene)polyols and mixtures thereof, said ethylene oxide capped polyol having the characteristics set forth in (a) above;
(c) a difunctional chain extender characterized by hydroxyl and/or amino groups containing amino hydrogen;
(d) said reaction taking place in the presence of a halogenated hydrocarbon blowing agent;
(e) said reaction being effected at an NCO index number in the range of from 94 to 105;
and
(f) in the presence of polymer particles stably dispersed in said quasi-prepolymer (a) above and/or capped polyol (b) above, the total polymer content not exceeding about 25% by weight, based on the total weight of the formulation.

5 more elements

An integral skin microcellular polyether polyurethane product essentially free of sink marks, possessing a smooth surface essentially devoid of blemishes, and a specific gravity of from 0.4 to about 0.7 gm/cm.sup.3, produced by reacting a system comprising:

(a) liquid quasi-polyoxyethyleneoxypropylene prepolymers having a crystalline point below about 13.degree. C. resulting from the reaction of (1) a mixture consisting essentially of (i) a normally-solid diphenylmethane diisocyanate, and small amounts of (ii) the carbodiimide of diphenylmethane diisocyanate and/or the uretone imine of diphenylmethane diisocyanate or (iii) the carbodiimide of tolylene diisocyanate and/or the uretone imine of tolylene diisocyanate;
with (2) an ethylene oxide capped polyol of the group consisting of poly(oxyethyleneoxypropylene)polyols and polymer/poly(oxyethyleneoxypropylene)polyols and mixtures thereof, said ethylene oxide capped polyol having a hydroxyl equivalent weight of about 750 to about 3000, a hydroxyl functionality of 2 to 3, an oxyethylene cap of about 10 to about 30% by weight, and an internal oxyethylene content of from 0 and upwards to 40% by weight, the total oxyethylene content of said capped polyol not exceeding about 50% by weight, the remainder of the capped polyol consisting essentially of oxypropylene;
(b) an ethylene oxide capped polyol of the group consisting of poly(oxyethyleneoxypropylene)polyols and polymer/poly(oxyethyleneoxypropylene)polyols and mixtures thereof, said ethylene oxide capped polyol having a hydroxyl equivalent weight of about 850 to about 2500, a hydroxyl functionality of from about 2.1-2.2 to about 2.8, an ethylene oxide cap of from about 10 to 25% by weight, an internal oxyethylene content of from 0 to 40% by by weight, the total oxyethylene content of said capped polyol not exceeding about 50% by weight, the remainder of the capped polyol consisting essentially of oxypropylene;
(c) a difunctional chain extender characterized by hydroxyl and/or amino groups consisting amino hydrogen;
(d) said reaction taking place in the presence of a halocarbon blowing agent and without the use of water as a secondary blowing agent;
(e) said reaction being effected at an NCO index number in the range of from 94 to 105;
and
(f) in the presence of polymer particles stably dispersed in said quasi-prepolymer (a) above and/or capped polyol (b) above, the total polymer content not exceeding about 20% by weight, based on the total weight of the system.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/594,574Filed 29 Mar 1984
Granted: 17 Dec 1985
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

C08G 18/797
Characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates: containing…
C08G 18/10
Processes: prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
C08G 18/40
Characterised by the compounds used containing active hydrogen: high-molecular-weight compounds
C08G 18/4841
And other oxyalkylene units: containing oxyethylene end groups