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Preparation method of slow-release foamed polyurethane

A foaming polyurethane, slow-release technology, applied in the field of foaming polyurethane, can solve the problems of material shrinkage elasticity, high content of polyurethane amine groups, low foaming density, etc.

Inactive Publication Date: 2021-02-02
中山杰伟鞋业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Among the two current foaming methods, chemical foaming is the commonly used foaming method, but its foaming effect is related to the amount of isocyanate and water. Increasing the amount of isocyanate can improve the foaming effect of polyurethane and reduce the density of foamed polyurethane , but at the same time, it will also lead to a higher content of amine groups in the foamed polyurethane, and the properties of the polyurethane will become brittle
Therefore, the foamed polyurethane obtained by chemical foaming usually has a relatively high density, and because the polyurethane heats up during foaming, the air pressure of the polyurethane bubbles is usually low, resulting in material shrinkage and poor elasticity.
The polyurethane obtained by physical foaming has low foaming density and very good elasticity, but because it requires converting carbon dioxide and pentane into supercritical fluid under high pressure, it requires high equipment, and only a few manufacturers have the relevant equipment to prepare this type of material

Method used

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  • Preparation method of slow-release foamed polyurethane

Examples

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preparation example Construction

[0034] A kind of preparation method of slow-release foaming polyurethane provided by the invention comprises the following steps:

[0035] 1. Add the cracking catalyst to the carbon dioxide-based polymer for pre-cracking to obtain the pre-cracking product A;

[0036] 2. Add the pre-cracking product A to the foamed polyurethane prepolymer, and stir evenly at a preset temperature to obtain a mixture B;

[0037] 3. Extrude the mixture B, and release it after cooling to obtain the finished product.

[0038] In step (1), the cracking temperature is 120-160° C., and the cracking time is 10-60 minutes; in step (2), the preset temperature is 40-60° C. Because the pre-cracking in the step (one) will break the carbon dioxide-based polymer molecular chain, so a high temperature of 120 to 160° C. is needed; the pre-cracking product A formed after the pre-cracking takes place in the step (two) is a melting reaction, Only a low temperature of 40-60°C is required, and the foamed polyuretha...

Embodiment 1

[0056] A preparation method of slow-release foaming polyurethane, comprising the following steps:

[0057] 1. Adding 0.5wt% of diethylzinc to the carbon dioxide-based polymer for pre-cracking, the cracking temperature is 160°C, and the cracking time is 30 minutes to obtain the pre-cracking product A;

[0058] Wherein, the carbon dioxide-based polymer is a propylene oxide copolymer / carbon dioxide binary copolymer with a molecular weight of 10,000 to 50,000;

[0059] 2. Add 0.5 wt% of the pre-cracking product A to the foamed polyurethane prepolymer, and stir evenly for 15 seconds at 45°C to obtain a mixture B;

[0060] 3. Extrude the mixture B, the air pressure in the mold is 0.3atm, the mold temperature is kept between 90-95°C for 20 minutes, and then the finished product is obtained by cooling and demolding.

[0061] After testing, the density of foamed polyurethane after molding is 0.25g / cm 3 .

Embodiment 2

[0063] A preparation method of slow-release foaming polyurethane, comprising the following steps:

[0064] 1. Add 0.8wt% of diethylzinc to the carbon dioxide-based polymer for pre-cracking. The cracking temperature is 150° C. and the cracking time is 30 minutes to obtain the pre-cracking product A;

[0065] Wherein, the carbon dioxide-based polymer is a propylene oxide copolymer / carbon dioxide binary copolymer with a molecular weight of 10,000 to 50,000;

[0066] 2. Add 1 wt% of the pre-cracking product A to the foamed polyurethane prepolymer, and stir evenly for 15 seconds at 45°C to obtain a mixture B;

[0067] 3. Extrude the mixture B, the air pressure in the mold is 0.5atm, the mold temperature is kept between 90-95°C, and the holding time is 30min, and then the finished product is obtained by cooling and demolding.

[0068] After testing, the density of foamed polyurethane after molding is 0.23g / cm 3 .

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Abstract

The invention discloses a preparation method of slow-release foamed polyurethane, which comprises the following steps: 1, adding a cracking catalyst into a carbon dioxide-based polymer, and carrying out pre-cracking to obtain a pre-cracked product A; 2, adding the pre-cracked product A into a foamed polyurethane prepolymer, and conducting uniform stirring at a preset temperature to obtain a mixture B; and 3, carrying out extrusion molding on the mixture B, and conducting cooling and demolding to obtain a finished product. The method is good in foaming effect and low in finished product density.

Description

technical field [0001] The invention relates to the technical field of foamed polyurethane, in particular to a preparation method of slow-release foamed polyurethane. Background technique [0002] Foamed polyurethane is a widely used material, which has good shock resistance, heat insulation, sound insulation and other properties. It is mainly used in shoe material substrates, sound insulation and heat insulation panels, packaging foam, etc. [0003] Chemical foaming is the reaction of ester and water to generate carbon dioxide to achieve the effect of foaming; while physical foaming refers to the use of carbon dioxide or pentane and other substances, which are gaseous at normal temperature and pressure, and are transformed under high pressure. It is a liquid, and then these foaming substances are fully mixed with other components of polyurethane and then extruded together. Due to the change in pressure after extrusion, these substances are rapidly vaporized to achieve the f...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G18/10C08G18/44C08G101/00
CPCC08G18/10C08G18/44C08G2101/00
Inventor 王明武朱江波许铁辉徐常威
Owner 中山杰伟鞋业有限公司