Alkali lignin oxidized starch modified urea-formaldehyde glue and production method thereof

A technology of oxidizing starch and modifying urea-formaldehyde, applied in the direction of adhesives, aldehyde/ketone condensation polymer adhesives, adhesive types, etc. Low cost and less free formaldehyde

Inactive Publication Date: 2009-11-11
ZHEJIANG FORESTRY UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this technology has not yet paid attention to the problem of less stable glue and easy precipitation.

Method used

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  • Alkali lignin oxidized starch modified urea-formaldehyde glue and production method thereof
  • Alkali lignin oxidized starch modified urea-formaldehyde glue and production method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Embodiment 1 (comparison table 1 raw material and its weight portion proportioning value and pH value): the industrial formaldehyde, 130 parts of alkali lignin, 24 parts of oxidized starch, 2 parts of borax that the purity of 60 parts by weight are respectively and 400 parts of industrial water are added to the reaction kettle at one time, and the pH value of the reaction environment in the kettle is adjusted to 9 with a NaOH solution of 30% by weight, and the temperature is raised to 90 ° C within 30 minutes, and the temperature is maintained for 65 minutes after the reaction Cool to room temperature, and put it in barrels.

Embodiment 2

[0017] Embodiment 2: Add raw materials and their parts by weight with reference to the values ​​shown in Example 2 in Table 1, adjust the pH value to 9.5 with 30% NaOH, heat up to 93° C. in 45 minutes, keep the reaction for 60 minutes, cool to normal temperature and put Packed in drums.

Embodiment 3

[0018] Embodiment 3: Add raw materials and parts by weight with reference to the value shown in Example 3 in Table 1, adjust the pH value to 10 with 30% NaOH solution, heat up to 95°C within 60 minutes, keep the temperature for 55 minutes, and cool to normal temperature Packed in buckets.

[0019] The rest of Examples 4-7 were added according to the raw materials, parts by weight, and pH values ​​corresponding to Examples 4-7 in the table, and the rest were made by referring to the methods of Examples 1-3.

[0020] It should be noted that the percentage concentration of the NaOH solution used as a catalyst does not have to be limited to a value of 30%, and can be selected in a range of 20%-40% or even wider. However, as a material preparation, it is only necessary to prepare the most commonly used concentration. Therefore, let's target 30%.

[0021] Alkalis such as magnesium hydroxide and potassium hydroxide can also be used to adjust the pH value.

[0022] Among the above s...

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Abstract

The invention relates to an alkali lignin oxidized starch modified urea-formaldehyde glue which is prepared by the following raw materials according to the mix proportion by weight parts: 235-245 parts of industrial formaldehyde with the purity of 37 percent, 133-159 parts of industrial urea, 0.5-1.5 parts of polyvinyl alcohol, 5-7 parts of ammonia water, 30-50 parts of industrial water, NaOH solution with the amount which can respectively regulate pH value to 7-7.5 and 8.5-9 in two times and 100-300 parts of alkali lignin oxidized starch modifier. The modified urea-formaldehyde glue is brown colloidal fluid, the coating 4 cups viscosity at the temperature of 25 DEG C is 40-50s, the density is 1.10-1.25g/cm, the solid content is 40 percent-50 percent and the average formaldehyde release amount is 1.2mg/L and the modified urea-formaldehyde glue achieves E1 level. The production of the modified glue adopts three steps of: 1) purchasing or self-making the modifier; 2) preparing the other various raw materials; and 3) adding the materials in a reaction kettle for reaction and production. The modified glue has low cost, small free formaldehyde release amount, good water resistance and good stability.

Description

technical field [0001] The invention relates to a wood adhesive, which is a modified urea-formaldehyde adhesive and a production method thereof. Background technique [0002] Using alkali lignin extracted from papermaking waste liquid as a modified material for wood adhesives to modify urea-formaldehyde adhesives is a set of waste liquid treatment, waste utilization, cost reduction, reduction of dependence on petroleum and release of free formaldehyde Small and other good things with multiple interests, there are more and more people who are interested in this and have taken action, so relevant materials are also frequently reported. However, in the prior art, a single alkali lignin is mostly used as a modifier, and the lignin-based urea-formaldehyde resin adhesive is prepared after the alkali lignin is extracted and purified. Pollution; and these urea-formaldehyde glues modified with alkali lignin are easy to precipitate, and the pot life is short during use. CN1854233 di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09J161/24C08G12/40
Inventor 于红卫金春德
Owner ZHEJIANG FORESTRY UNIVERSITY
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