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Preparation method of phenolic resin having narrow molecular weight distribution

A narrow molecular weight distribution, phenolic resin technology, used in aldehyde/ketone condensation polymer adhesives, adhesive types, adhesives, etc., can solve problems such as increased cost and waste water pollution, inability to obtain molecular weight distribution, and complex processes

Active Publication Date: 2012-07-18
SHANDONG SHENGQUAN NEW MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

U.S. Patent US6045966 adopts the method of precipitating phenol-formaldehyde polymer in batches with organic solvent\water mixture to classify phenolic resin to achieve the purpose of controlling the molecular weight distribution of phenolic resin. This type of method consumes a large amount of organic solvent, which increases the cost and waste water Pollution
Japanese patent 00135829.4 synthesizes a narrow molecular weight distribution resin synthesis method based on the process of alkali first and then acid. This method is complex and the molecular weight distribution of the prepared phenolic resin is above 1.2. It is impossible to obtain a narrower molecular weight distribution and more uniform properties of the phenolic resin.

Method used

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  • Preparation method of phenolic resin having narrow molecular weight distribution

Examples

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preparation example Construction

[0044] The preparation method provided by the present invention specifically includes: adding phenol, which accounts for 50% of the total aldehydes, into a device with a reflux device, adjusting the temperature to 40-45°C, adding an alkali catalyst, adjusting the temperature to 55-85°C, and constant temperature 1-3 hours, add the remaining 50% aldehyde, measure the content of free aldehydes in the aldehyde compound at a constant temperature of 55-85℃, and the content of the aldehyde compound is 3~5wt%, quickly decrease the temperature to 48-50℃, add low molecular polymerization initiator, and rapidly decrease the temperature To below 25℃, settle for 24 hours, filter and dry.

[0045] The resin synthesized by the invention has a narrow molecular weight distribution, the production process is simple and environmentally friendly, and the filtered filtrate can be adjusted for wood bonding. Due to the excessive aldehyde, the utilization rate of phenolic compounds is 100%, which protect...

Embodiment 1

[0047] Put 500g of phenol and 500g of formaldehyde into a reaction flask equipped with stirring, thermometer and reflux device, adjust the temperature to 40℃, add 25g of sodium hydroxide, heat up to 60℃ for constant temperature reaction for 2 hours, add 500g of formaldehyde, adjust the temperature to 50 Keep the temperature at a constant temperature until the free aldehyde accounts for 3.8wt% of the aldehyde compound. Add urea and keep the temperature constant for 10 minutes. While stirring, the reflux temperature is quickly reduced to 12°C, settled for 24 hours, and filtered and dried.

[0048] The molecular weight distribution of the phenolic resin prepared in this example was detected by gel solution chromatography GPC, and the results are as follows figure 1 As shown, it can be seen that the molecular weight distribution Mw / Mn of the phenolic resin prepared in this embodiment is 1.05, which is smaller than the molecular weight distribution of the prior art. It shows that the ...

Embodiment 2

[0050] Put 500g of phenol and 500g of formaldehyde into a reaction flask equipped with stirring, thermometer and reflux device, adjust the temperature to 45℃, add 25g sodium hydroxide, heat up to 50℃ and react at a constant temperature for 3 hours, add 500g formaldehyde, adjust the temperature to 45 Keep the temperature at a constant temperature until the free aldehyde accounts for 4.5wt% of the aldehyde compound content, add urea, keep the temperature constant for 10 minutes, rapidly reduce the vacuum and reflux temperature to 12°C while stirring, settle for 24 hours, and filter and dry.

[0051] The molecular weight distribution of the phenolic resin prepared in this example was detected by gel solution chromatography GPC. The molecular weight distribution Mw / Mn of the phenolic resin prepared in this example was 1.03, which was smaller than the molecular weight distribution of the prior art. It shows that the phenolic resin with narrow molecular weight distribution prepared by t...

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Abstract

The invention provides a preparation method of a phenolic resin having narrow molecular weight distribution. The preparation method comprises the following steps: a) mixing a phenol compound, a first aldehyde compound and an alkaline catalyst for polycondensation reaction to obtain a prepolymer; b) mixing a second aldehyde compound with the precpolymer for further polycondensation reaction; and c) when the content of free aldehyde in a reaction system is 3-5wt%, adding a low-molecule polymer initiator in the reaction system for further reaction to obtain the phenolic resin. The phenolic resin prepared by using the method is narrow in molecular weight distribution; production process is environment-friendly; and filtrate obtained after filtration can be used for wood adhesion through regulation, thereby ensuring the utilization rate of phenol and protecting environment.

Description

Technical field [0001] The invention relates to the field of polymer preparation, in particular to a method for preparing a phenolic resin with a narrow molecular weight distribution. Background technique [0002] Phenolic resin is a polymer obtained by reaction polycondensation of phenol and aldehyde. Because phenolic resin has a phenol unit and a regular molecular chain structure, phenolic resin has comprehensive properties such as heat resistance and good flame retardancy, and has become one of the important industrial resin varieties in the past century. The preparation of phenolic resin generally uses phenol and formaldehyde. It is obtained by polycondensation under the action of a catalyst. Since the polymerization is polycondensation and gradual polymerization, its resin system is determined to be a phenolic mixture with a variety of molecular weight distributions. It has the defects of asynchronous curing and large internal stress during curing. [0003] Now more and more ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G8/10C08G8/24C08G8/04C09J161/10C09J161/12
Inventor 邢介名姜广锋焦锋董岳
Owner SHANDONG SHENGQUAN NEW MATERIALS CO LTD