Solid-state method for treating polyamide and polyester articles
AssigneeGreen Theme Technologies Inc.
InventorXia Zhao
Life of this patent
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Abstract
Solid-state branching and/or crosslinking of aliphatic polyamide or polyester articles is achieved using a topical approach. A surface of the article is coated with a composition that includes a polyene and a free radical initiator. The article and applied coating are then heated to induce branching and/or crosslinking in the polyamide or polyester. This is performed below the crystalline melting temperature of the polyamide or polyester, or in the case of a fabric, below the melting temperature of the fibers in the fabric. Fabrics treated in this manner exhibit reduced or even no dripping in vertical flame tests.
Claims20
A solid-state method for treating a thermoplastic article which thermoplastic article comprises a thermoplastic material component having a crystalline melting temperature of at least 100° C., in which the thermoplastic material component comprises at least one thermoplastic resin, the method comprising:
- a) at a temperature below the crystalline melting temperature of the thermoplastic material component, applying a coating composition to at least one surface of the article and into contact with at least one thermoplastic polymer of the thermoplastic material component of the article, wherein the coating composition comprises i) at least 20 weight percent of at least one polyene compound, the polyene compound having 2 to 6 vinyl groups, an equivalent weight per vinyl group of up to 500 g/equivalent, and (ii) at least one peroxy or azo free radical initiator;
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- b) heating the coated article to a temperature to decompose the peroxy or azo free radical initiator to form free radicals and produce crosslinking in the thermoplastic resin to provide a crosslinked thermoplastic article exhibiting one or more of i) non-melting behavior characteristics of thermoset resins, ii) delayed ignition when exposed to an open flame or heat compared to the thermoplastic article prior to the crosslinking, and iii) reduced dripping when exposed to an open flame or heat compared to the thermoplastic article prior to the crosslinking, wherein the temperature is below the crystalline melting temperature of the thermoplastic material component.
A solid-state method for treating a thermoplastic fabric which fabric comprises thermoplastic material fibers, the thermoplastic material fibers including a first type of thermoplastic resin fibers alone or a blend of thermoplastic resin fibers with fibers of at least one other polymer that is not the first type of thermoplastic resin fibers, and the thermoplastic material fibers having a melting temperature of at least 100° C. as measured according to ASTM D7138-16, the method comprising:
- a) at a temperature below the melting temperature of the thermoplastic material fibers, applying a coating composition to at least one surface of the fabric, wherein the coating composition comprises i) at least 20 weight percent of at least one polyene compound, the polyene compound having 2 to 6 vinyl groups, an equivalent weight per vinyl group of up to 500 g/equivalent, and (ii) at least one peroxy or azo free radical initiator;
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- b) heating the coated fabric to a temperature of at least 70° C. but below the melting temperature of the thermoplastic material fibers to decompose the peroxy or azo free radical initiator to form free radicals and produce branching and/or crosslinking in the thermoplastic material fibers to provide a crosslinked thermoplastic fabric exhibiting one or more of i) non-melting behavior characteristics of thermoset resins, ii) delayed ignition when exposed to an open flame or heat compared to the thermoplastic fabric prior to the crosslinking, and iii) reduced dripping when exposed to an open flame or heat compared to the thermoplastic fabric prior to the crosslinking.
A solid-state method for reducing melting and/or dripping of thermoplastic fabric which fabric comprises thermoplastic fibers, the thermoplastic fibers including a first type of thermoplastic resin fibers alone or a blend of thermoplastic resin fibers with fibers of at least one other polymer that is not the first type of thermoplastic resin fibers, the thermoplastic fibers having a melting temperature of at least 100° C. as measured according to ASTM D7138-16, the method comprising:
- a) at a temperature below the melting temperature of the thermoplastic fibers, applying a coating composition to at least one surface of the fabric, wherein the coating composition comprises i) at least 20 weight percent of at least one polyene compound, the polyene compound having 2 to 6 vinyl groups, an equivalent weight per vinyl group of up to 500 g/equivalent, and (ii) at least one peroxy or azo free radical initiator;
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- b) heating the coated fabric to a temperature of at least 70° C. but below the melting temperature of the thermoplastic fibers for a period of 1 minute to 2 hours to provide a crosslinked thermoplastic fabric exhibiting one or more of i) non-melting behavior characteristics of thermoset resins, ii) delayed ignition when exposed to an open flame or heat compared to the thermoplastic fabric prior to the crosslinking, and iii) reduced dripping when exposed to an open flame or heat compared to the thermoplastic fabric prior to the crosslinking.
Dependencies are inferred from the claim text.