阅读说明：本技术 多层胶合板用脲醛树脂用填料及其制备方法 (Filler for urea-formaldehyde resin for multilayer plywood and preparation method thereof ) 是由 卜立新 卜洪伟 彭来 李建章 秦向东 俞红 王东 于 2020-04-29 设计创作，主要内容包括：本发明公开了一种多层胶合板用脲醛树脂用填料及其制备方法,所述填料由以下重量份的原料制备而成：煤矸石粉30~40重量份、棉粕粉30~50重量份、沸石粉5~10份,纳米沸石和木质素复合颗粒10~15份、增强剂1~3重量份、增稠剂4~8重量份、酸性剂8~12重量份。本发明方法中以无机填料和棉粕为主要原料配合少量助剂制备脲醛树脂填料,并且进一步有效利用了木质素,成本低,可有效利用工业副产物代替面粉填料,节约资源；并可有效增强脲醛树脂胶粘剂强度、降低甲醛释放量、增加预压性能；并且能够进一步提高使用本发明脲醛树脂填料制作的多层胶合板的机械性能和防火性能。(The invention discloses a filler for urea-formaldehyde resin for multilayer plywood and a preparation method thereof, wherein the filler is prepared from the following raw materials in parts by weight: 30-40 parts of coal gangue powder, 30-50 parts of cottonseed meal powder, 5-10 parts of zeolite powder, 10-15 parts of nano zeolite and lignin composite particles, 1-3 parts of reinforcing agent, 4-8 parts of thickening agent and 8-12 parts of acid agent. The method of the invention uses the inorganic filler and the cottonseed meal as main raw materials to prepare the urea-formaldehyde resin filler by matching with a small amount of auxiliary agents, further effectively utilizes the lignin, has low cost, can effectively utilize industrial byproducts to replace flour filler, and saves resources; the strength of the urea-formaldehyde resin adhesive can be effectively enhanced, the formaldehyde release amount is reduced, and the prepressing performance is improved; and the mechanical property and the fire resistance of the multilayer plywood manufactured by the urea resin filler can be further improved.)

1. The filler for the urea-formaldehyde resin for the multilayer plywood is characterized by being prepared from the following raw materials in parts by weight: 30-40 parts of coal gangue powder, 30-50 parts of cottonseed meal powder, 5-10 parts of zeolite powder, 10-15 parts of nano zeolite and lignin composite particles, 1-3 parts of reinforcing agent, 4-8 parts of thickening agent and 8-12 parts of acid agent.

2. The filler for urea-formaldehyde resin for multi-layer plywood as claimed in claim 1, wherein the method for preparing the nano zeolite and lignin composite particles comprises the following steps:

1) performing normal-temperature normal-pressure plasma treatment on the lignin solution with the pH value of 11.4 by adopting quartz glass with the thickness of 2mm to prevent discharge, wherein the treatment time is 5-10 s, the treatment power is 50-150W, the treatment gas is air, the gas flow is 1L/min, and the lignin solution obtained after treatment is filtered and dried for later use;

2) carrying out ultrasonic dispersion on nano zeolite in a mixed system of ethanol and water, adding lignin obtained in the step 1) under the stirring condition, adjusting the pH to 2-5, reacting for 20-60 minutes, carrying out centrifugal filtration, washing precipitates, and drying to obtain nano zeolite and lignin composite particles.

3. The filler for urea resin for plywood according to claim 1, wherein said lignin is alkali lignin.

4. The filler for urea resin for plywood according to claim 1, wherein the zeolite powder is 200 mesh.

5. The filler for urea resin for multi-ply plywood as claimed in claim 1, wherein said thickener is one of hydroxypropyl methyl cellulose or hydroxyethyl cellulose ethyl ether; the reinforcing agent is triglycidyl isocyanurate; the acid agent is ferrous sulfate which is a titanium white industrial byproduct.

6. The filler for urea resin for multi-ply plywood according to claim 1, wherein the reinforcing agent is prepared by: putting 1mol of isocyanuric acid into a four-neck flask, keeping the temperature to 60 ℃, adding 1% of stannic chloride and 0.05mol of sodium hydroxide, slowly dripping 4mol of epoxy chloropropane monomer, reacting at 90-100 ℃ for 5 hours, cooling to 50 ℃, adding 0.15mol of sodium hydroxide, stirring for 20 minutes, neutralizing redundant alkali, distilling residual epoxy chloropropane under reduced pressure, and refining the reinforcing agent in ethanol.

7. The filler for urea resin for multi-ply plywood according to claim 1, wherein the cotton pulp powder is 100 mesh; the coal gangue powder is 300 meshes.

8. The preparation method of the filler for the urea-formaldehyde resin for the multilayer plywood as claimed in any one of claims 1 to 7, characterized by comprising the following steps:

1) grinding cotton pulp to 100 meshes to obtain cotton pulp powder, adding 30 weight parts and 70 weight parts of water into a reaction kettle, adding 3 weight parts of sodium hydroxide and 6 weight parts of urea, stirring for 20 minutes, heating to 80 ℃, continuously stirring for 1 hour, cooling and drying, and grinding into 300-mesh powder;

2) grinding coal gangue into 300 meshes to obtain coal gangue powder, and then mixing and stirring the coal gangue powder with the powder prepared in the step (1), the zeolite powder, the nano zeolite and lignin composite particle reinforcing agent, the acid agent and the thickening agent uniformly to obtain a product.

Technical Field

The invention relates to a plywood filler, in particular to a urea-formaldehyde resin filler for a multilayer plywood for preparing a plywood and a preparation method thereof, belonging to the field of plywood fillers.

Background

With the improvement of the living standard of people and the continuous and stable development of industries such as building, decoration, packaging and the like, the yield of the artificial board in China is rapidly increased. The total yield of the artificial boards, the yield of the plywood, the yield of the furniture and the yield of the wooden floors are continuously positioned at the top of the world for many years. In 2018, the total yield of the artificial boards in China is 2.99 hundred million m3, which accounts for about 50% of the total yield in the world. Calculated according to the average production of 10m3 artificial boards per ton of adhesive, the wood adhesive consumption in China in 2018 is about 2000 ten thousand tons (solid content is 50%), wherein the urea-formaldehyde resin and modified products thereof account for more than 80% of the total output of the adhesive and dominate. About 1000 million tons of the flour is used for plywood production, about 3000 million tons of flour fillers are consumed each year, and under the condition that the existing grain resources are in short supply, the waste is huge.

Among the commonly used fillers are mainly: starches (e.g., flour, starch, sorghum flour, tapioca flour, etc.). The filler has the water absorption function, can prevent the glue solution from excessively permeating into the veneer to cause glue shortage to influence the gluing quality, can also increase the initial viscosity, and is a more common filler. ② proteins (such as bean flour and blood powder). Because the filler contains protein and can react with free formaldehyde in resin, the cross-linking is easily generated between molecules to generate an irreversible product (protein gel); in addition, the blood powder can improve the water resistance and the bonding strength of the adhesive, and the bean powder can prolong the shelf life of the adhesive. This is therefore a very good filler, but is expensive. ③ celluloses (such as bark powder, peanut shell powder, wood powder and hydrolyzed corn cob powder). Because the fillers mostly contain polyphenol compounds such as lignin, the fillers can react with formaldehyde to generate copolymers and have the effect of improving the cementing quality, but the fillers have low viscosity (the lignin has overlarge viscosity), poor sizing performance and poor prepressing performance. Minerals (such as quartz powder, chalk powder, porcelain powder, bentonite and the like). The filler has the characteristics of wide source, low cost, high density, low viscosity and poor prepressing performance, and is easy to precipitate when the concentration of glue solution is low. As described above, the above measures can be used as a substitute for urea resin, but have many problems or cannot be popularized due to reasons such as excessively high production cost.

The applicant previously used coal gangue powder and cotton seed meal powder as main raw materials to prepare the filler for the urea-formaldehyde resin for the multilayer plywood (see patent CN 104762026), but further researches show that the filler has a space for further improvement, and the filler for the urea-formaldehyde resin with better performance is obtained.

Disclosure of Invention

In order to solve the problems, the invention designs a filler for urea-formaldehyde resin for multilayer plywood and a preparation method thereof.

The technical scheme of the invention is as follows:

the filler for the urea-formaldehyde resin for the multilayer plywood is prepared from the following raw materials in parts by weight: 30-40 parts of coal gangue powder, 30-50 parts of cottonseed meal powder, 5-10 parts of zeolite powder, 10-15 parts of nano zeolite and lignin composite particles, 1-3 parts of reinforcing agent, 4-8 parts of thickening agent and 8-12 parts of acid agent.

Preferably, the preparation method of the nano zeolite and lignin composite particle comprises the following steps:

1) performing normal-temperature normal-pressure plasma treatment on the lignin solution with the pH value of 11.4 by adopting quartz glass with the thickness of 2mm to prevent discharge, wherein the treatment time is 5-10 s, the treatment power is 50-150W, the treatment gas is air, the gas flow is 1L/min, and the lignin solution obtained after treatment is filtered and dried for later use;

2) carrying out ultrasonic dispersion on nano zeolite in a mixed system of ethanol and water, adding lignin obtained in the step 1) under the stirring condition, adjusting the pH to 2-5, reacting for 20-60 minutes, carrying out centrifugal filtration, washing precipitates, and drying to obtain nano zeolite and lignin composite particles.

Preferably, the lignin is alkali lignin.

Preferably, the zeolite powder is 200 meshes.

Preferably, the thickener is one of hydroxypropyl methyl cellulose or hydroxyethyl cellulose ethyl ether; the reinforcing agent is triglycidyl isocyanurate; the acid agent is ferrous sulfate which is a titanium white industrial byproduct.

Preferably, the preparation method of the reinforcing agent comprises the following steps: putting 1mol of isocyanuric acid into a four-neck flask, keeping the temperature to 60 ℃, adding 1% of stannic chloride and 0.05mol of sodium hydroxide, slowly dripping 4mol of epoxy chloropropane monomer, reacting at 90-100 ℃ for 5 hours, cooling to 50 ℃, adding 0.15mol of sodium hydroxide, stirring for 20 minutes, neutralizing redundant alkali, distilling residual epoxy chloropropane under reduced pressure, and refining the reinforcing agent in ethanol.

Preferably, the cotton meal powder is 100 meshes; the coal gangue powder is 300 meshes.

Preferably, the preparation method of the filler for urea-formaldehyde resin for multilayer plywood is characterized by comprising the following steps:

1) grinding cotton pulp to 100 meshes to obtain cotton pulp powder, adding 30 weight parts and 70 weight parts of water into a reaction kettle, adding 3 weight parts of sodium hydroxide and 6 weight parts of urea, stirring for 20 minutes, heating to 80 ℃, continuously stirring for 1 hour, cooling and drying, and grinding into 300-mesh powder;

2) grinding coal gangue into 300 meshes to obtain coal gangue powder, and then mixing and stirring the coal gangue powder with the powder prepared in the step (1), the zeolite powder, the nano zeolite and lignin composite particle reinforcing agent, the acid agent and the thickening agent uniformly to obtain a product.

The invention has the advantages that:

1) the method of the invention uses the inorganic filler and the cottonseed meal as main raw materials to prepare the urea-formaldehyde resin filler by matching with a small amount of auxiliary agents, further effectively utilizes the lignin, has low cost, can effectively utilize industrial byproducts to replace flour filler, and saves resources;

2) the filler in the method can effectively enhance the strength of the urea-formaldehyde resin adhesive, reduce the release amount of formaldehyde and increase the prepressing performance; the mechanical property and the fire resistance of the multilayer plywood manufactured by using the urea resin filler can be further improved;

3) the lignin is treated by adopting the plasma, under the condition of controlling specific treatment strength and treatment conditions, the hydrophilicity of the lignin can be improved, the dispersion performance of the lignin is improved, the surface of the lignin treated by the plasma becomes rough, then the nano zeolite and the lignin composite particles are prepared by the treated lignin and the nano composite zeolite, and the dispersion effect of the particles after the composite in the filler is good.

The present invention will be further described with reference to the following specific examples.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.

All percentages used in the present invention are by weight unless otherwise indicated.