Thermal stability improved polyformaldehyde resin composition and preparation method thereof

A polyoxymethylene resin, thermal stability technology, applied in the field of resin composition and its preparation, can solve the problems of insufficient notched impact strength, polyoxymethylene is easy to oxidize and discolor at high temperature, and polyoxymethylene mold scale is less

Inactive Publication Date: 2013-03-27
SHANGHAI GENIUS ADVANCED MATERIAL (GRP) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this type of formaldehyde absorbent is easy to migrate to the surface of the product and form mold scale during molding processing, which seriously affects the surface quality and production efficiency of the product, and the addition of this type of formaldehyde absorbent will reduce the mechanical properties of polyoxymethylene
[0004] In commercial polyoxymethylene compositions, homopolyamides, copolyamides or amide oligomers are often used as formaldehyde absorbents. Chinese invention patent CN1569957A discloses the thermal stabilization of polyamides on polyoxymethylene. It has stable structure and high molecular weight. It is not easy to volatilize and has good compatibility with polyoxymethylene, but due to the amide group, polyoxymethylene is easy to oxidize and discolor at high temperature, which affects the apparent quality of the product
[0005] Chinese invention patent CN1300245C discloses thermally stable polyoxymethylene containing melamine-formaldehyde condensate and its pre

Method used

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  • Thermal stability improved polyformaldehyde resin composition and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Weigh the following materials by weight percentage:

[0043] Polyoxymethylene resin 96%, hyperbranched polyester (see structural formula 1, the bonding group is an ester group, the terminal group is a hydroxyl group, and the number average molecular weight is 5000-6000) 0.6%, N, N'-bis-[3-( 3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine 0.2%, tris(2.4-di-tert-butylphenyl)phosphite 0.1%, magnesium oxide 0.1%, stearin Calcium Acid 3%.

[0044] Dry the polyoxymethylene resin at 80°C for 3 hours, then put it into a high-speed mixer and mix it with the above-mentioned other materials, use a vented co-rotating twin-screw extruder to melt and blend, extrude and granulate, and the screw speed is 280 rpm Minutes, barrel temperature (temperature) is:

[0045] Hopper Zone 1, Zone 2, Zone 3, Zone 4, Zone 5, Zone 6, Zone 7, Zone 8, Zone 9

[0046] Room temperature 165 170 175 180 185 185 190 190 190 185

Embodiment 2

[0048] Weigh the following materials by weight percentage:

[0049] Polyoxymethylene resin 91.8%, hyperbranched polyester (see structural formula 1, the bonding group is an ester group, the terminal group is a hydroxyl group, and the number average molecular weight is 9000-10000) 2%, tetrakis [β-(3,5-ditertiary Butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester 0.6%, tris(2.4-di-tert-butylphenyl)phosphite 0.3%, magnesium oxide 0.3%, calcium stearate 5%.

[0050] Dry the polyoxymethylene resin at 80°C for 3 hours, then put it into a high-speed mixer and mix it with the above-mentioned other materials, use a vented co-rotating twin-screw extruder to melt and blend, extrude and granulate, and the screw speed is 210 rpm minute, the barrel temperature (°C) is:

[0051] Hopper Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 Zone 8 Zone 9 Machine head

[0052] Room temperature 160 165 170 170 175 175 180 180 180 175

Embodiment 3

[0054]Weigh the following materials by weight percentage:

[0055] Polyoxymethylene resin 94.2%, hyperbranched polyester (see structural formula 1, the bonding group is an ester group, the terminal group is a hydroxyl group, and the number average molecular weight is 7000-8000) 1%, β-(3,5-di-tert-butyl 0.4% stearyl-4-hydroxyphenyl) propionate, 0.2% tris(2.4-di-tert-butylphenyl) phosphite, 0.2% magnesium hydroxide, 4% magnesium stearate.

[0056] Dry the polyoxymethylene resin at 80°C for 3 hours, then add the above-mentioned other materials into a high-speed mixer and mix them, use a vented co-rotating twin-screw extruder to melt and blend, extrude and granulate, and the screw speed is 250 rpm minute, the barrel temperature (°C) is:

[0057] Hopper Zone 1, Zone 2, Zone 3, Zone 4, Zone 5, Zone 6, Zone 7, Zone 8, Zone 9

[0058] Room temperature 160 170 170 175 180 180 185 185 185 180

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Abstract

The present invention relates to a thermal stability improved polyformaldehyde resin composition and a preparation method thereof. The preparation method comprises: adding 91.8-96% by weight of a polyformaldehyde resi, 0.6-2% by weight of a hyperbranched polyester, 0.2-0.6% by weight of a main antioxidant, 0.1-0.3% by weight of an secondary antioxidant, 0.1-0.3% by weight of a formic acid absorber, and 3-5% by weight of a lubricant to a high-speed mixer to mix, and adopting an exhaust type co-rotating twin screw extruder to carry out melt mixing and extrusion granulation to prepare the thermal stability improved polyformaldehyde resin composition, wherein a rotation speed of the screw is 210-280 rotation/min, and a material cylinder temperature is 160-190 DEG C. Compared with the composition in the prior art, the composition of the present invention has the following characteristics that: formation of excessive mold scale and formaldehyde gas during a mold molding processing process can be avoided, product discoloration can be inhibited, and excellent thermal stability is provided.

Description

technical field [0001] The invention relates to a resin composition and a preparation method thereof, in particular to a polyoxymethylene resin composition with improved thermal stability and a preparation method thereof. Background technique [0002] Due to the special molecular structure of polyoxymethylene, its thermal stability is poor, so the thermal stabilization of polyoxymethylene is the most important and basic key technology in its synthesis or processing application. POM is prone to produce formaldehyde gas during thermal degradation, which not only pollutes the environment, but also easily oxidizes formaldehyde molecules to formic acid, which induces acidolysis of POM, resulting in further deterioration of the material's performance. [0003] At present, low-molecular-weight compounds such as melamine and dicyandiamide are generally used as formaldehyde absorbents in industry. It absorbs formaldehyde through the addition of active H on its amine groups to formald...

Claims

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Application Information

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IPC IPC(8): C08L59/00C08L67/00C08K13/02C08K5/526C08K3/22C08K5/098C08K5/17C08K5/134B29C47/92B29C48/92
CPCB29C48/04B29C48/40B29C48/92B29C2948/9259B29C2948/92704B29C2948/92885B29C2948/92895
Inventor 王贻孙
Owner SHANGHAI GENIUS ADVANCED MATERIAL (GRP) CO LTD
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