A kind of preparation method of novolac resin

A technology of novolac resin and phenols, which is applied in the field of preparation of novolak resin to achieve the effect of high fluidity and low softening point

Active Publication Date: 2016-06-29
营口圣泉高科材料有限公司
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, there is no relevant research on how to increase the content of oligomers and improve the flow properties of the resin in the structure design of novolac resin

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of preparation method of novolac resin
  • A kind of preparation method of novolac resin
  • A kind of preparation method of novolac resin

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Add 500g of phenol, 151g of formaldehyde (37%), and 10g of oxalic acid into a stirred 1000ml four-necked flask with a condenser and mix them. The pH of the mixed solution was 1.5. Raise the temperature to reflux at 100°C, the conversion rate of formaldehyde reaches 90%, add sodium hydroxide at 85°C, adjust the pH to 6.5, and add 65g of formaldehyde (37%). The temperature was raised to reflux for 2 hours. Continue to heat up and dehydrate until the temperature reaches 160° C., and then the novolac resin of Example 1 can be obtained.

Embodiment 2

[0034] Add 500g of phenol, 181 formaldehyde (37%), and 10g of oxalic acid into a stirred 1000ml four-necked flask with a condenser and mix them. The pH of the mixed solution was 1.7. Raise the temperature to reflux at 100°C, the conversion rate of formaldehyde reaches 89%, add sodium hydroxide at 85°C, adjust the pH to 6.5, and add 77g of formaldehyde (37%). The temperature was raised to reflux for 2 hours. Continue to heat up and dehydrate until the temperature reaches 160° C., and then the novolac resin of Example 2 can be obtained.

Embodiment 3

[0036] Add 500g of phenol, 211g of formaldehyde (37%), and 10g of oxalic acid into a stirred 1000ml four-necked flask with a condenser and mix them. The pH of the mixed solution was 1.9. Raise the temperature to reflux at 100°C, the conversion rate of formaldehyde reaches 90%, add sodium hydroxide at 85°C, adjust the pH to 6.5, and add 91g of formaldehyde (37%). The temperature was raised to reflux for 2 hours. Continue to heat up and dehydrate until the temperature reaches 160° C., and then the novolac resin of Example 3 can be obtained.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to the technical field of phenolic resins, in particular to a preparation method of novolac resins: mixing phenols and the first part of aldehydes, adjusting the pH to 1-3, raising the temperature to reflux reaction to obtain a mixed solution; adjusting the pH of the mixed solution To 4-9, add the remaining aldehyde, after the reaction is complete, heat and dehydrate to 160°C to obtain novolac resin; the amount of the first part of aldehyde added accounts for 30-75% of the total amount of aldehyde added. By controlling the batch addition of aldehyde and the pH control of the reaction process, the resin with high oligomer content and wide resin molecular weight distribution in the resin is obtained; under the similar molecular weight situation, compared with the resin of the original process, the method can be used A novolak resin with low softening point and high fluidity is obtained.

Description

technical field [0001] The invention relates to the technical field of phenolic resins, in particular to a preparation method of novolac resins. Background technique [0002] Phenolic resin is a general term for resins produced by the reaction of phenols and aldehydes in the presence of catalysts. It is the earliest polymer material produced industrially. It has excellent mechanical properties, ablation resistance, and electrical insulation properties. Widely used in molding compound, friction material, casting, mold material and other fields. [0003] Novolac resins are obtained by reacting phenols and aldehydes in the presence of acidic catalysts. The molar ratio of phenols and aldehydes is 1:0.5-0.8. Under the catalyst, the phenols and aldehydes firstly react in a homogeneous phase, and then transform into a heterogeneous reaction with the deepening of the reaction, reaching a certain reaction end point. High-temperature dehydration or supplemented by vacuum can obtain ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(China)
IPC IPC(8): C08G8/10C08K3/04C08G8/04C08G8/08C08G8/20C08G8/22
Inventor唐一林刘翠华李枝芳袁善菊董强
Owner营口圣泉高科材料有限公司