# US 2022/0033997 A1 · Polyurethane elastic fiber with flame retardant function and preparation method thereof

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- Number: US 2022/0033997 A1
- Document ID: US20220033997A1
- Status: Published application
- Kind: A1
- Application number: 17/504,514
- Filed: 2021-10-19
- Published: 2022-02-03
- Earliest claimed: 2019-04-22
- Assignees: Yantai Tayho Advanced Materials Co., Ltd.
- Applicants: Yantai Tayho Advanced Materials Co., Ltd.
- Inventors: Yongjun CHEN; Qianli MA
- Web page: https://patentgrep.com/patent/US20220033997A1

## CPC

- C08G 18/5084: {Phosphate compounds}
- D01F 6/94: of other polycondensation products
- C08G 18/2865: {Compounds having only one primary or secondary amino group; Ammonia}
- C08G 18/3228: {acyclic}
- C08G 18/4684: {containing phosphorus}
- C08G 18/5075: {having phosphorus}
- C08G 18/6651: {with compounds of group C08G18/3225 or polyamines of C08G18/38}
- C08G 18/6685: {with compounds of group C08G18/3225 or polyamines of C08G18/38}
- C08G 18/7671: {containing only one alkylene bisphenyl group}
- D01D 5/04: Dry spinning methods {(D01D5/0038 takes precedence)}
- D01F 1/07: for making fire- or flame-proof filaments
- D01F 1/10: Other agents for modifying properties
- D01F 6/84: from copolyesters
- C08L 2201/02: Flame or fire retardant/resistant
- C08L 2203/12: used for fibers
- D10B 2331/10: polyurethanes
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- D10B: INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES

## Abstract

Disclosed are a polyurethane elastic fiber with a flame retardant function and a preparation method thereof. The polyurethane elastic fiber is prepared by using a polyether diol containing phosphorus elements or a polyester diol containing phosphorus elements as a raw material to react with 4,4′-diphenylmethane diisocyanate to prepare a prepolymer, extending the chain using an organic amine to obtain a polyurethane solution, and dry spinning with the polymer solution to prepare the polyurethane fiber. The limit oxygen index of the prepared polyurethane fiber was between 25% and 32%.

## Claims

### Claim 1

A preparation method of a polyurethane elastic fiber with a flame retardant function, comprising:
step 1 of reacting a diol containing flame-retardant elements with excess 4,4′-diphenylmethane diisocyanate to prepare a prepolymer end-capped by isocyanate, and dissolving the prepolymer in an organic solvent to form a prepolymer solution;
step 2 of adding a diamine or a mixed amine of a diamine and a monoamine to the prepolymer solution for chain extension reaction to obtain a polyurethane solution; and
step 3 of mixing the polyurethane solution with an anti-yellowing agent and an antioxidant, followed by curing, filtering, defoaming, and then dry spinning to obtain the polyurethane elastic fiber with flame retardant function.

### Claim 2 (depends on 1)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein the diol containing flame-retardant elements in step 1 is a polyether diol containing phosphorus elements or a polyester diol containing phosphorus elements.

### Claim 3 (depends on 2)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 2, wherein the polyether diol containing phosphorus elements contains —P—O— or —P—C— structures, and has a phosphorus content of 0.5 wt % to 5 wt %; and the polyether diol containing phosphorus elements contains phosphate structures, and has a phosphorus content of 0.5 wt % to l0 wt %, and an acid value of 3.0 or lower.

### Claim 4 (depends on 3)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 3, wherein the phosphorus content in the polyether diol containing phosphorus elements is 1 wt % to 3 wt %, the phosphorus content in the polyester diol containing phosphorus elements is 1 wt % to 6 wt %, and the acid value is 2.0 or lower.

### Claim 5 (depends on 1)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein in step 1, a molar ratio of the 4,4′-diphenylmethane diisocyanate to the diol containing flame-retardant elements is (1.5:1) to (2.5:1).

### Claim 6 (depends on 1)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein the organic solvent in step 1 is N,N-dimethylformamide, N,N-dimethylacetamide, or a mixture thereof.

### Claim 7 (depends on 1)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein, in step 2, a molar ratio of amino functional groups in the diamine or the mixed amine of the diamine and the monoamine to the isocyanate at ends of the prepolymer is (1.00:1) to (1.05:1).

### Claim 8 (depends on 1)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein in step 2, the diamine is selected from the group consisting of ethylenediamine, 1,2-propanediamine, 1,3-propylenediamine 2-methyl-1,5-pentanediamine, and a combination thereof in any ratio; and the monoamine is selected from the group consisting of dimethylamine, diethylamine, methylethylamine, and a combination thereof in any ratio.

### Claim 9 (depends on 1)

The preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein, when the mixed amine of the diamine and the monoamine is adopted in step 2, a molar ratio of the monoamine to the diamine is (0.02:1) to (0.15:1).

### Claim 10 (depends on 1)

A polyurethane elastic fiber with a flame retardant function, prepared by the preparation method of the polyurethane elastic fiber with the flame retardant function according to claim 1, wherein a limit oxygen index of the polyurethane elastic fiber is 25 wt % to 32 wt %.