# US 11,028,263 B2 · Polyoxymethylene resin composition

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- Number: US 11,028,263 B2
- Document ID: US11028263B2
- Status: Granted
- Kind: B2
- Application number: 16/342,461
- Filed: 2017-10-13
- Published: 2020-02-13
- Granted: 2021-06-08
- Earliest claimed: 2016-10-17
- Assignees: Korea Engineering Plastics Co., Ltd.
- Applicants: Korea Engineering Plastics Co., Ltd.
- Inventors: Seung Hwan Joo; Chang Ho Lee; Kwan Yong Choi
- Web page: https://patentgrep.com/patent/US11028263B2

## CPC

- C08L 71/02: Polyalkylene oxides
- C08K 3/32: Phosphorus-containing compounds
- C08K 5/053: Polyhydroxylic alcohols
- C08K 5/21: Urea; Derivatives thereof, e.g. biuret
- C08L 59/02: Polyacetals containing polyoxymethylene sequences only
- C08J 5/00: Manufacture of articles or shaped materials containing macromolecular substances (manufacture of semi-permeable membranes B01D67/00 - B01D71/00)
- C08K 5/34922: {Melamine; Derivatives thereof}
- C08K 2003/325: {Calcium, strontium or barium phosphate}
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)

## Abstract

A polyoxymethylene resin composition including a polyoxymethylene homopolymer, a polyhydric alcohol, and a calcium phosphate compound, which has excellent thermal stability and a low weight-reduction rate and thus can be favorably used in various industrial fields and used as an engineering plastic in fields of machine parts and the like.

## Claims

### Claim 1

A polyoxymethylene resin composition comprising:
a polyoxymethylene homopolymer, a polyhydric alcohol containing three or more hydroxy groups in a molecule in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the polyoxymethylene homopolymer;
a calcium phosphate compound in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the polyoxymethylene homopolymer; and
an ethylene urea in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the polyoxymethylene homopolymer;
wherein the polyoxymethylene homopolymer is obtained by polymerizing formaldehyde or trioxane in the presence of a polymerization catalyst and then adding a melamine-based polymerization terminator,
wherein the polyoxymethylene resin composition has a weight-reduction rate of 9% or less and a CH2O generation amount of 100 ppm or less.

### Claim 2 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the melamine-based polymerization terminator is selected from compounds represented by Chemical Formula 1 below:
in Chemical Formula 1, R1 to R6 are each independently selected from hydrogen, C1 to C6 alkyl, C1 to C6 alkoxy, and —CH2OR7, and a case where R1 to R6 are all hydrogen is excluded,
R7 is C1 to C6 alkyl or —R8CO2R9, R8 is C1 to C6 alkylene, and R9 is C1 to C6 alkyl.

### Claim 3 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the melamine-based polymerization terminator is added in an amount of 0.01 to 50 times the molar amount of the polymerization catalyst used.

### Claim 4 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the polyoxymethylene homopolymer has a weight average molecular weight of 10,000 to 500,000 g/mol.

### Claim 5 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the polyhydric alcohol is any one or a mixture of two or more selected from glycerin, trimethylolethane, trimethylolpropane, 2-methyl-1,2,3-propanetriol, 1,2,5-pentanetriol, 1,2,4-butanetriol, hexanetriol, triethanolamine, diglycerin, pentaerythritol, dipentaerythritol, tripentaerythritol, tetraethanol ethylenediamine, methyl glucoside, aromatic diamine-tetraethanol adduct, sorbitol, 2-hydroxymethylpropane-1,3-diol, 2-methyl-1,2,4-butanetriol, 1,3,5-trihydroxymethylbenzene, 1,2,3,6-hexanetetrol, and cyclodextrin.

### Claim 6 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the calcium phosphate compound is any one or a mixture of two or more selected from hydroxyapatite, tricalcium phosphate, dicalcium phosphate, and calcium phosphate.

### Claim 7 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the ethylene urea is 2-imidazolidone or imidazolidin-2-one.

### Claim 8 (depends on 1)

The polyoxymethylene resin composition of claim 1, wherein the polyoxymethylene resin composition has a melt index of 1 to 15 g/10 min measured at 190° C. and 2.16 kg, a tensile strength of 67 to 75 MPa, a elongation at yield of 15 to 25%, and an impact strength of 7 to 15 kJ/m2.