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Method for preparing controllable viscosity hydroxyl-terminated polydimethylsiloxane

A dimethylsiloxane and hydroxyl-blocked technology, which is applied in the field of production of hydroxyl-blocked polydimethylsiloxane with controllable viscosity, can solve the problems of difficult control of viscosity and low laboratory reproducibility, and reduce the Cross-linking, the effect of uniform and transparent products

Active Publication Date: 2013-06-26
HUBEI XINGRUI SILICON MATERIAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, during the synthesis of 107 silicone rubber, the viscosity is difficult to control during polymerization, and the laboratory reproducibility rate is low.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Hydrolyzate pretreatment: add 300g of hydrolyzate and 200g of water into a 500mL three-necked flask, stir for 30min at 50~75℃, add 20ppm of reagent A (reagent A is anion exchange resin and activated carbon), stir for 30min, then add 20ppm For reagent B, adjust the pH to 7.1, stop stirring, let stand, and separate to obtain the desired hydrolyzate.

[0019] Alkali glue preparation: add 150g DMC to a 250mL three-necked bottle, add 0.5g KOH after dehydration at 50-120°C, and polymerize at 130-150°C to obtain KOH alkali glue.

[0020] 107 Silicone rubber synthesis: Add the pretreated hydrolyzate into a 500mL reactor, raise the temperature, and dehydrate under vacuum. After the material is dehydrated, add 55ppm KOH alkali glue, heat up and polymerize at 100°C, and add phosphoric acid aqueous solution when the reaction system reaches the required viscosity. Neutralization. After neutralization, the system removes low molecules at a suitable temperature and vacuum until no fra...

Embodiment 2

[0022] Pretreatment of hydrolyzate: Add 300g of hydrolyzate and 200g of water into a 500mL three-necked flask, stir for 30min at a temperature of 50~75℃, add 20ppm of reagent A (reagent A is an anion exchange resin), stir for 30min, then add 30ppm of reagent B , adjust the pH=7.1, stop stirring, let it stand, and separate to obtain the desired hydrolyzate.

[0023] Alkali glue preparation: add 150g DMC to a 250mL three-necked bottle, add 0.5g KOH after dehydration at 50°C-120°C, and polymerize at 130-150°C to obtain KOH alkali glue.

[0024] 107 Silicone rubber synthesis: Add the pretreated hydrolyzate into a 500mL reactor, raise the temperature, and dehydrate under vacuum. After the material is dehydrated, add 55ppm KOH alkali glue, heat up and polymerize at 100°C, and add phosphoric acid aqueous solution when the reaction system reaches the required viscosity. Neutralization. After neutralization, the system removes low fractions at a suitable temperature and vacuum until no...

Embodiment 3

[0026] Pretreatment of hydrolyzate: Add 300g of hydrolyzate and 200g of water into a 500mL three-necked flask, stir for 30min at a temperature of 50~75°C, add 20ppm of reagent A (reagent A is silver nitrate), stir for 30min, then add 20ppm of reagent B, Adjust the pH to 7.1, stop stirring, let stand, and separate to obtain the desired hydrolyzate.

[0027] Alkali glue preparation: add 150g DMC to a 250mL three-necked bottle, add 0.5g KOH after dehydration at 50°C-120°C, and polymerize at 130-150°C to obtain KOH alkali glue.

[0028] 107 Synthesis of silicone rubber: Add the pretreated hydrolyzate into a 500mL reactor, raise the temperature, and dehydrate under vacuum. After the material is dehydrated, add 55ppm KOH alkali glue, heat up and polymerize at 120°C, and add phosphoric acid aqueous solution when the reaction system reaches the required viscosity. Neutralization. After neutralization, the system removes low fractions at a suitable temperature and vacuum until no fract...

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PUM

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Abstract

The invention relates to the field of organosilicone, and in particular relates to a method for preparing controllable viscosity hydroxyl-terminated polydimethylsiloxan. The method comprises the steps of: mixing hydrolysate with water, adding a reagent A and a reagent B to remove impurities under proper temperature, then standing and separating so as to obtain the required hydrolysate; polymerizing the hydrolysate under the catalysis of a KOH alkaline glue at 100-140 DEG C, adding a phosphoric acid aqueous solution to neutralize when a reaction system reaches the required viscosity, and heating to remove low molecular weight substances so as to obtain the 107 silicon rubber. By utilizing hydrolysate pretreatment, the influences of impurities such as chloride ions and chain links with three functional degrees to the system are greatly reduced; and the viscosity of the system can be slowly and uniformly increased through controlling a catalyst, and the reaction is easy to control.

Description

technical field [0001] The invention relates to the field of organosilicon, in particular to a method for producing hydroxyl-terminated polydimethylsiloxane with controllable viscosity. Background technique [0002] Hydroxyl-terminated polydimethylsiloxane (107 silicone rubber) is a linear reactive polysiloxane terminated by hydroxyl, which can be made into linear or cross-linked polysiloxane with high molar mass. It is the basic raw material for preparing room temperature vulcanized silicone rubber, etc. It is widely used in the bonding and sealing of electronic components and combined keys, moisture-proof and shock-proof and insulating materials. With the large increase of high-rise buildings, the demand for 107 silicone rubber as a raw material for building sealants has also greatly increased. [0003] The most common synthesis method of 107 silicone rubber is to use cyclic dimethylsiloxane, such as D4 (octamethyltetrasiloxane), D5 (decamethylpentasiloxane) or DMC (D3~D7...

Claims

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Application Information

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IPC IPC(8): C08G77/16C08G77/08C08G77/34
Inventor 陈海平苗刚喻黎明汪民康胡丹
Owner HUBEI XINGRUI SILICON MATERIAL CO LTD
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