Urea-formaldehyde resin adhesive with ultra-low formaldehyde release and preparation process thereof

A technology of formaldehyde release and urea-formaldehyde resin, applied in the direction of adhesives, aldehyde/ketone condensation polymer adhesives, adhesive types, etc., can solve the problem of large impact on the subsequent process of plywood, high formaldehyde release, and poor pre-compression and other problems, to achieve the effects of long open storage time, low formaldehyde emission and good pre-compression

Active Publication Date: 2016-09-21
BEIHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main problems of existing urea-formaldehyde resin adhesives are: 1. High formaldehyde emission, most of which are ≥0.48mg / L; 2. Poor pre-pressing performance, which has a great impact on the subsequent process of plywood production; 3. Relatively solid content Low, the solid content of urea-formaldehyde resin adhesives in the market is about 40%-52%

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] 1) Heat the reaction kettle to 58°C, add 35% formaldehyde solution, and then adjust the pH to 8.45 with 8.5mol / l sodium hydroxide;

[0020] 2) When the temperature is increased to 68°C, 42% urea is added to the reactor, and then the reaction is kept at 89°C for 40 minutes. 58% urea is added and reacted at 89°C for 40 minutes. In the process, 45% formic acid is added dropwise. Control the pH of the reaction at 6.5;

[0021] 3) Control the temperature at 86°C, use a Tu-4 cup to measure the viscosity between 30 and 15 seconds, adjust the pH value to 8.1 with 8.5mol / l sodium hydroxide, add hydroxymethylcellulose, and react for 15 minutes;

[0022] 4) Add aluminum sulfate to react for 15 minutes, adjust the pH to 7.7 with 45% formic acid, and start to cool down. When the temperature drops to 65°C, add polyvinyl alcohol and pure water, keep 68°C and stir for 30 minutes and continue to cool down.

[0023] 5) When the temperature drops to room temperature, filter and discharge.

[0024]...

Embodiment 2

[0027] 1) Heat the reactor to 58°C, add 35% formaldehyde solution, and then adjust the pH to 8.35 with 9mol / l sodium hydroxide;

[0028] 2) When the temperature is increased to 68°C, 45% urea is added to the reaction kettle, and then the reaction is kept at 89°C for 40 minutes. 55% urea is added and reacted at 89°C for 40 minutes. In the process, 45% formic acid is added dropwise. Control the pH of the reaction at 6.6;

[0029] 3) Control the temperature at 86°C, use the Tu-4 cup to measure the viscosity between 30 and 16s, adjust the pH to 8.1 with 8.5mol / l sodium hydroxide, add hydroxymethylcellulose, and react for 15 minutes;

[0030] 4) Add aluminum sulfate to react for 15 minutes, adjust the pH to 7.8 with 45% formic acid, and start to cool down. When the temperature drops to 65°C, add polyvinyl alcohol and pure water, keep at 70°C and stir for 30 minutes and continue to cool down.

[0031] 5) When the temperature drops to room temperature, filter and discharge.

[0032] The mass ...

Embodiment 3

[0035] 1) The reaction kettle is heated to 58°C, 40% formaldehyde solution is added, and then the pH value is adjusted to 8.35 with 10mol / l sodium hydroxide;

[0036] 2) When the temperature is increased to 68°C, 45% urea is added to the reaction kettle, and then the reaction is kept at 89°C for 40 minutes. 55% urea is added and reacted at 89°C for 40 minutes. In the process, 45% formic acid is added dropwise. Control the pH of the reaction at 6.6;

[0037] 3) Control the temperature at 86°C, use the Tu-4 cup to measure the viscosity between 30 and 15 seconds, adjust the pH value to 8.1 with 8.5mol / l sodium hydroxide, add hydroxymethyl cellulose, and react for 15 minutes;

[0038] 4) Add aluminum sulfate to react for 15 minutes, adjust the pH to 7.1 with 45% formic acid, and start to cool down. When the temperature drops to 65°C, add polyvinyl alcohol and pure water, keep at 70°C and stir for 30 minutes and continue to cool down.

[0039] 5) When the temperature drops to room temperat...

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PUM

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Abstract

The invention relates to an ultralow-formaldehyde-release urea-formaldehyde resin adhesive and a preparation process thereof. The preparation process comprises the following steps: adjusting the pH value of a formaldehyde solution by using sodium hydroxide; then adding urea for reaction, and dropwise adding formic acid during the reaction to control the reaction pH value; then under a certain viscosity, adjusting the pH value by using sodium hydroxide; adding hydroxyl methyl cellulose, and adding aluminum sulfate for reaction; adjusting the pH value by using formic acid; adding polyvinyl alcohol and pure water for reaction; and cooling to room temperature to obtain the ultralow-formaldehyde-release urea-formaldehyde resin adhesive. According to the ultralow-formaldehyde-release urea-formaldehyde resin adhesive and the preparation process provided by the invention, the obtained urea-formaldehyde resin adhesive has the characteristics of low formaldehyde release quantity, good pre-pressing property, long opening depositing time, strong initial viscosity and the like, and meanwhile, the solid content is greatly improved, so that the urea-formaldehyde resin adhesive is suitable for production of veneers, shaving boards, fiber boards and ecological boards.

Description

Technical field [0001] The invention relates to the technical field of organic adhesives, in particular to a urea-formaldehyde resin adhesive with ultra-low formaldehyde release and a preparation process thereof. Background technique [0002] Urea-formaldehyde resin adhesive is a kind of thermosetting polymer adhesive developed earlier. Due to its simple process, cheap raw materials, high bonding strength, colorless and transparent, etc., it is widely used in the production of plywood, particleboard, medium density fiberboard, artificial board and interior decoration industries. The main problems of existing urea-formaldehyde resin adhesives are: 1. High formaldehyde emission, mostly ≥0.48mg / L; 2. Poor pre-compression, which has a greater impact on the subsequent processes of plywood production; 3. Relative solid content Lower, the current market urea-formaldehyde resin adhesive solid content is about 40% -52%. Summary of the invention [0003] The content of the present inventi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09J161/24C09J101/28C09J129/04C09J11/04C08G12/12
Inventor 时君友张吉平
Owner BEIHUA UNIV
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