CN111333799A - Synthetic method of urea-formaldehyde resin with ultralow formaldehyde release - Google Patents
Synthetic method of urea-formaldehyde resin with ultralow formaldehyde release Download PDFInfo
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- C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
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Abstract
The invention discloses a method for synthesizing urea-formaldehyde resin with ultralow formaldehyde release, relates to the field of chemical organic polymer polymerization, and particularly relates to the field of synthesis of urea-formaldehyde resin adhesives. The invention comprises four steps: firstly, reacting a high-concentration formaldehyde aqueous solution with urea with the dosage of 25-50% of the formula to synthesize pre-acetal, then carrying out addition reaction with the urea under the weak base condition, carrying out condensation reaction under the acidic condition, and carrying out curing reaction under the action of soybean protein hydrolysate. The soybean protein hydrolysate contains a plurality of small molecular amino acids, the amino groups and the hydroxyl groups in the amino acids and free formaldehyde have polycondensation reaction and acetal reaction to form a polymer with a crosslinked net structure among macromolecules, a large amount of hydrophilic groups are sealed, unreacted free formaldehyde is captured, the content of the free formaldehyde in the synthesized urea resin is lower than the E1 standard newly issued by the nation (GB18580-2017 climate box method), and ultra-low formaldehyde release is achieved.
Description
Field of the invention
The invention relates to the field of organic polymer polymerization, in particular to the field of synthesis of urea-formaldehyde resin adhesives.
Background
The reduction of natural forest resources promotes the rapid development period of the artificial board industry in China, and the consumption of wood adhesives for manufacturing the artificial boards is huge. Urea-formaldehyde resin (UF) is easy to obtain and low in manufacturing cost, and becomes the most widely applied wood adhesive worldwide. Urea-formaldehyde (UF) resin is the variety with the largest yield in wood adhesives, and is one of the developed and applied high-molecular adhesives. The urea-formaldehyde resin adhesive has the advantages of simple production process, wide raw material source, low cost, convenience in use, high initial viscosity, high bonding strength and the like, so that the urea-formaldehyde resin adhesive is widely applied to industries such as woodware processing, artificial board production, paper bonding, indoor decoration and the like, and the dosage of the urea-formaldehyde resin adhesive used for preparing the urea-formaldehyde resin adhesive accounts for more than 80% of the total consumption of other products.
The prior art for producing the environment-friendly urea-formaldehyde resin adhesive in China is relatively lagged behind, and has the main defects that free formaldehyde is released in the using process, so that the environment is polluted and the human health is seriously harmed. Therefore, the research and development of the environment-friendly low-toxicity urea-formaldehyde resin adhesive is always a research hotspot of the wood adhesive industry.
Recently, the national quality control bureau and the national standardization and management committee have officially released the revised limit on formaldehyde emission in artificial boards and products thereof for interior decoration and finishing materials (GB18580-2017), which will be officially implemented from 5 months and 1 day in 2018. The new edition of standards improves the requirement of formaldehyde release limit, the value of the formaldehyde release limit is specified to be 0.124 mg/cubic meter, and the limit mark is E1; this means that the limit of formaldehyde release and the detection method in China have been in direct contact with the world.
Some manufacturers in China capture free formaldehyde in urea-formaldehyde resin by using polyvinyl alcohol, melamine and other raw materials, but because addition reaction and polycondensation reaction are reversible equilibrium reaction, the addition of the auxiliary agent only improves the functions of brittleness, strength, water resistance and the like of urea-formaldehyde resin, and the elimination effect of the free formaldehyde is poor and does not reach the limit standard of the free formaldehyde.
Urea is the most commonly used formaldehyde scavenger, but the reactivity of urea is relatively low, and the input amount of urea needs to be increased in order to achieve the ideal formaldehyde elimination effect, more urea can cause more free urea in the resin, and the urea interval between resin molecules can cause adverse effect on the adhesive property of the urea-formaldehyde resin, and the adhesive strength, the curing time and the viscosity of the urea-formaldehyde resin are influenced.
The research of applying vegetable protein to urea-formaldehyde resin adhesive to eliminate free formaldehyde in China is less, the development and the start are late, the units participating in the research are few at present, and the strength is weak.
Lanhui (2002) 12 studied that defatted soybean flour was chemically modified with acylating agent and crosslinking agent, respectively, and then freeze-dried, and then a wood adhesive with about 20% soybean flour content was prepared with Ca (OH)2-NaOH-NaSiO3, and the adhesiveness and water resistance of soybean flour were improved by modifying with acylating agent and crosslinking agent. Zhao Ke et al (2002) 13 studied the composite adhesive of soybean protein isolate-polyvinyl alcohol, soybean protein isolate-white latex, and provided an environment-friendly adhesive with higher initial adhesion for manufacturing disposable plant fiber snack boxes. Wangweison et al (2003) [6] have considered that development of other vegetable proteins than soy protein as wood adhesives should be paid attention. The Sejian Zhong (2003) [14] adopts mercaptoethanol, urea, acetic anhydride, succinic anhydride, sodium dodecyl sulfate (sDS), sodium sulfite and the like to modify wheat gluten, so as to obtain the modified gluten wood adhesive with higher bonding strength (2147-3109 MPa) in a dry state, and the heat sealing condition of the protein adhesive is researched.
These studies have resulted in the production of adhesives using soy protein only, and not the modification of urea-formaldehyde resins to remove free formaldehyde. The product has comprehensive performance indexes such as cross-linking strength, initial viscosity, curing conditions and the like in use, has great difference with urea-formaldehyde resin adhesive in the aspects of raw materials, product price and the like, and cannot replace the urea-formaldehyde resin adhesive to have great effect and application prospect in the board market.
Object of the Invention
The invention aims to solve the problem that the free formaldehyde in the urea-formaldehyde resin is overproof at present by using the soybean protein hydrolysate to capture and seal the end of the free formaldehyde in the urea-formaldehyde resin during the synthesis process of the urea-formaldehyde resin, so that the product meets the requirement of the national E1 mandatory standard.
Technical scheme
The invention comprises four steps: firstly, 50% formaldehyde solution reacts with a part of urea to synthesize urea formaldehyde precondensate (UFC); then, in an alkaline environment, urea formaldehyde pre-condensed liquid (replacing formaldehyde solution) is used for carrying out addition reaction with the residual urea; in an acidic medium, only intermolecular polycondensation reaction is carried out; finally, under the alkaline condition, the urea-formaldehyde resin and the soybean protein hydrolysate act to absorb the free formaldehyde in the resin.
The urea formaldehyde pre-shrinking liquid (UFC) is synthesized, the urea formaldehyde pre-shrinking liquid is used for replacing a formaldehyde solution to react with urea to synthesize the urea formaldehyde resin adhesive, the synthesis of the urea formaldehyde resin under the condition of low molar ratio of U/F can be realized, and the dehydration is mainly reduced and the content of free formaldehyde in a product is reduced.
Urea-formaldehyde resin is synthesized by polymerizing urea-formaldehyde pre-condensed liquid and urea, and the synthetic route of the urea-formaldehyde resin adopts 'weak base-weak acid-weak base'; the first step of addition reaction, ammonia water is used for adjusting the alkalinity of materials, and hydroxymethylation reaction is carried out at a weak base stage; secondly, regulating the acidity of reactants by using formic acid, wherein in the weak acid stage, the hydroxymethyl ureas and the urea are subjected to polycondensation reaction to generate initial-stage resin; and (3) after the reaction end point is reached, adjusting the reactants to be in weak alkalinity by using sodium hydroxide alkali liquor, and stopping the reaction by using the urea resin under the weak alkalinity condition.
And in the curing reaction stage, the hydrolyzed soybean protein is reacted with urea-formaldehyde resin to capture free formaldehyde.
The soybean protein hydrolysate raw material is derived from soybeans which belong to bean products with large use amount and low price, and the soybeans comprise the following chemical components: 13.12% of water, 19.29% of fat, 21.55% of carbohydrate, 2.94% of crude fiber, 38.45% of protein, 4.5% of ash and the like.
70% of storage proteins in the soybeans are spherical proteins, polypeptide chain substances are formed by poly-glycine, glutamic acid, alanine, phenylalanine, leucine and the like, most polar and nonpolar groups in polypeptide chains form a stable multi-stage structure through van der Waals force, hydrogen bonds and hydrophobic interaction, and a compact sphere is formed.
The structural formula is as follows:
the polarity and the non-polarity of amino groups in the spherical soybean protein are sealed, so that the spherical soybean protein is difficult to participate in the reaction of urea resin and can not effectively remove free formaldehyde.
Preparing soybean protein hydrolysate: hydrolyzing the soybean protein in an alkaline water solution at a specific reaction temperature under a constant pressure for a certain reaction time to obtain colorless, alkaline, viscous and flowable soybean protein hydrolysate at room temperature.
The soybean protein hydrolysate is composed of glycine, glutamic acid, lysine, alanine, phenylalanine amino acid and other small molecular amino acids.
The chemical structural formula is as follows:
the soybean protein hydrolysate contains various micromolecular amino acid components and hydroxyl components, is easy to perform addition reaction and acetal reaction with formaldehyde to form a polymer with a crosslinked network structure among macromolecules, blocks a large amount of hydrophilic groups, and captures unreacted free formaldehyde, thereby removing the free formaldehyde in the urea-formaldehyde resin.
The experimental data show that: in the curing stage, when the addition amount of the soybean protein hydrolysate is increased by 1%, the content of free formaldehyde in the urea-formaldehyde resin can be reduced by 50%.
A synthetic method of urea-formaldehyde resin with ultralow formaldehyde release comprises the following process steps:
a pre-aldol reaction zone: the device consists of a formaldehyde storage tank, a pre-condensation reactor, a urea storage tank and an ammonia storage tank; a50% concentrated formaldehyde aqueous solution is adopted, urea is industrial grade urea, 1/2-1/4 of the formula usage amount is added, ammonia water is used for adjusting the pH value to be alkaline, steam is introduced into an interlayer of a reaction kettle for heating, the temperature is controlled to be 60-90 ℃, stirring reaction is carried out for 30-90 min, and urea formaldehyde resin pre-condensed liquid is generated.
B addition reaction zone: the device consists of an addition reaction kettle, an auxiliary agent storage tank, a urea storage tank and an ammonia water storage tank; adding pre-acetal and an auxiliary agent into a reaction kettle; adding urea twice according to the reaction process, wherein the using amount of the urea is 1/2-2/5 of the total amount; adjusting the pH value to be alkalescent by ammonia water; introducing steam into an interlayer of the reaction kettle for heating, and controlling the temperature to be 60-90 ℃; stirring for reaction, and condensing and refluxing generated steam through a reflux condenser; the reaction residence time is 30-90 minutes.
C, condensation reaction zone: comprises a formic acid storage tank and a condensation reaction kettle; adding formic acid into reaction materials, adjusting the pH value of the solution to be acidic by 3-6.5, introducing steam into an interlayer of the reaction kettle, and heating, wherein the temperature is controlled at 60-85 ℃; stirring and reacting, wherein the reaction residence time is 30-90 minutes, and the reaction end point is determined according to a viscosity method or cloud point.
D, curing reaction zone: consists of an alkaline solution storage tank, a soybean protein hydrolysate storage tank, a urea storage tank and a ripening reaction kettle; adjusting the pH value of the material to be alkaline by using an alkali liquor, wherein the alkali liquor is a 30% sodium hydroxide aqueous solution; adding the soybean protein hydrolysate and the balance of urea, introducing steam into a jacket to heat, stirring and reacting at 60-70 ℃, and keeping the reaction time for 30-60 min.
E detection and storage area: the device consists of a product detection device and a urea-formaldehyde resin storage tank; the product detection device is an online detection system, and the qualified product enters a urea-formaldehyde resin storage tank for later use.
In the pre-shrinking reaction zone, the material of the pre-shrinking reaction kettle is 304/Q235-B, an interlayer and a speed reduction stirring device; the other storage tank material is 304/Q235-B.
In the pre-condensation reaction zone, the urea is of industrial grade, the content of sulfate is less than 0.01 percent, the content of biuret is less than 0.7 percent, and the content of free ammonia is less than 0.015 percent.
In the pre-condensation reaction zone, the formaldehyde is in industrial grade, the concentration is more than or equal to 50 percent, and the formic acid is less than 0.1 percent; methanol is less than 1.5 percent, and ferrum is less than 0.0005 percent.
In the addition reaction zone, the material of the addition reaction kettle is 304/Q235-B, and the interlayer is provided with a speed-reducing stirring device; the other storage tank material is 304/Q235-B.
In the addition reaction zone, the auxiliary agent is polyvinyl alcohol, melamine or a mixture component thereof, wherein the polyvinyl alcohol is a 50% aqueous solution and has a model of 1799 or 1788; the alkali liquor is preferably ammonia water solution; the urea is of industrial grade, the content of sulfate is less than 0.01 percent, the content of biuret is less than 0.7 percent, and the content of free ammonia is less than 0.015 percent.
In the condensation reaction zone, the material of a condensation reaction kettle is 304/Q235-B, an interlayer and a speed reduction stirring device; the other storage tank material is 304/Q235-B.
In the condensation reaction zone, the acid solution is preferably formic acid aqueous solution, and the concentration of the acid solution is 30-60%.
A curing reaction zone, wherein the curing reaction kettle is made of 304/Q235-B, an interlayer and a speed reduction stirring device; the other storage tank material is 304/Q235-B.
A curing reaction zone, wherein the alkali liquor is 30% sodium hydroxide aqueous solution; the soybean hydrolyzed protein is a 50% aqueous solution; the urea is of industrial grade, the sulfate content is less than 0.01 percent, the biuret is less than 0.7 percent, and the free ammonia is less than 0.015 percent.
The soybean hydrolyzed protein has the following quality requirements: the content of sulfate is less than 0.015 percent, the content of free ammonia is less than 0.005 percent, the content of iron is less than 0.0005 percent, and the pH value is 7.5-11.5.
In the curing reaction zone, the addition amount of the soybean hydrolyzed protein is more than or equal to 2 percent (100 percent content), the reaction temperature is 40-70 ℃, and the reaction residence time is 20-60 min.
Advantageous effects
The invention utilizes the soybean protein hydrolysate to reduce the content of free formaldehyde in the urea-formaldehyde resin and lock the product formaldehyde free separation caused by reversible equilibrium reaction in the product, and simultaneously improves the prepressing performance problem of the urea-formaldehyde resin pressed plywood, the bonding strength of the glued product reaches the national standard, the contradiction between the bonding strength and the formaldehyde release amount is effectively solved, so that the plate product becomes a real green product, and the invention has strong market prospect.
The urea-formaldehyde resin adhesive prepared by utilizing the soybean protein hydrolysate is detected according to GB/T9846-containing 2004, and free formaldehyde indexes are detected by a climate box method of 'formaldehyde release limit in artificial boards of interior decoration and finishing materials and products thereof' (GB18580-2017) which is a standard newly issued by the state.
The results are shown in the table.
Detection index of main performance of UF resin
The performance of the synthesized urea-formaldehyde resin reaches the national standard, wherein the free formaldehyde index is lower than the national E1 standard.
Drawings
FIG. 1 is a block diagram of a process for synthesizing an ultra-low formaldehyde-releasing urea-formaldehyde resin, which is a schematic flow diagram for illustrating the present invention and shows only the necessary equipment for explaining the process, while other obviously required facilities such as meters, gas confluence equipment, pumps, valves, intermediate tanks, etc. are omitted.
FIG. 1 illustrates in numbered detail:
1. a formaldehyde storage tank; 2. a pre-aldol reactor; 3. a urea storage tank; 4. an ammonia water storage tank; 5. an addition reaction kettle; 6. an auxiliary agent storage tank; 7. a urea storage tank; 8. an ammonia water storage tank; 9. a reflux condenser; 10. a formic acid storage tank; 11. a condensation reaction kettle; 12. an alkali solution storage tank; 13. a soybean protein hydrolysate storage tank; 14. a urea storage tank; 15. a ripening reaction kettle; 16. a urea-formaldehyde resin storage tank; 17. Product detection device.
The invention is further described with the aid of the accompanying drawings:
(1) the raw materials of formaldehyde, alkali liquor, ammonia water, formic acid, urea and soybean protein hydrolysate are respectively from storage tanks in a plant area, are respectively sent to corresponding storage tanks in a workshop, are metered by a metering device according to a formula and are sent to a reaction kettle by a pump.
(2) Adding formaldehyde into a pre-condensation reaction kettle through a formaldehyde storage tank by a mass metering pump; starting stirring, adding ammonia water from an ammonia water storage tank, and adjusting the pH value to be 6-8; adding urea through a urea storage tank; and introducing steam into the interlayer, heating to 80-90 ℃, and controlling the reaction time to synthesize the urea-formaldehyde pre-shrinking liquid.
(3) Pumping the reacted urea formaldehyde pre-condensed liquid into an addition reaction kettle by a pump, and starting stirring; adding ammonia water from an ammonia water storage tank, and adjusting the pH value of the solution to 7-9; adding polyvinyl alcohol into the auxiliary agent storage tank; metering urea in a urea storage tank; introducing steam into a jacket to heat, and controlling the temperature to be 70-90 ℃; and (3) exchanging heat of steam generated by the reaction through a reflux cooler, refluxing the condensate into the reaction kettle, and finishing the reaction for 30-80 minutes.
(4) Pumping the reactants into a condensation reaction kettle by a pump, and starting stirring; adding formic acid into a formic acid storage tank, and adjusting and controlling the pH value to be acidic 3-6; introducing steam into an interlayer of the reaction kettle to heat, and controlling the temperature to be 60-90 ℃; the reaction end point was controlled by the cloud point method.
(5) Pumping the reactants into a ripening reaction kettle by a pump, and starting stirring; adding alkali liquor from an alkali liquor storage tank, and adjusting the pH value of the solution to 7-9; adding residual urea from a urea storage tank; adding the soybean protein hydrolysate liquid into a soybean protein hydrolysate storage tank, introducing steam into a jacket of a reaction kettle, heating, controlling the temperature to be 60-80 ℃, cooling after the reaction is finished, and discharging.
(6) The product is qualified after inspection, particularly free formaldehyde is detected according to the formaldehyde release limit value (GB18580-2017) in artificial boards and products of interior decoration and finishing materials, the formaldehyde release limit value is 0.124 mg/cubic meter (climate box method), and the product is pumped into a urea-formaldehyde resin storage tank for storage after being qualified.
Detailed description of the preferred embodiments (examples)
The raw materials of formaldehyde, alkali liquor, ammonia water, formic acid, urea and soybean protein hydrolysate are respectively from storage tanks in a plant area, are respectively sent to corresponding storage tanks in a workshop, are metered by a metering device according to a formula and are sent to a reaction kettle by a pump.
For the whole system N2Or other inert gas displacement, from the exhaust emission to a detection system oxygen content of less than 10 PPM.
Introducing 810Kg of formaldehyde into a pre-condensation reaction kettle by a mass pump through a formaldehyde storage tank (the formaldehyde content is 37.5%); starting stirring, adding ammonia water into an ammonia water storage tank, and adjusting the pH value to be 7-9.5; adding 135Kg of urea through a urea storage tank; and (3) introducing steam into the interlayer of the reaction kettle to heat, heating to 80-90 ℃, reacting for 60 minutes, and detecting to be qualified for later use.
Adding 337.5Kg of pre-polymerized urea-formaldehyde resin liquid into an addition reaction kettle by using a pump, adding ammonia water from an ammonia water storage tank, adjusting the pH value of the solution to be 6-9 by using the ammonia water, adding 25Kg of polyvinyl alcohol solution into an auxiliary agent storage tank, heating steam in a kettle jacket, controlling the temperature to be 60-90 ℃, stirring until the solution is dissolved, adding 185Kg of urea into a urea storage tank, cooling steam generated in the reaction by using a reflux cooler, adding the cooling liquid into the reaction kettle again, and stopping the reaction for 60-80 minutes.
Pumping the reactants into a condensation reaction kettle by a pump; starting stirring, adding formic acid from a formic acid storage tank, and adjusting and controlling the pH value to be acidic 3-6.5; introducing steam into an interlayer of the reaction kettle to heat, and controlling the temperature to be 60-90 ℃; the residence time of the polycondensation reaction is 40-80 minutes (the reaction end point is controlled by a cloud point method).
Pumping the reactants into a curing reaction kettle by a pump; starting stirring, adding alkali liquor into an alkali liquor storage tank, and quickly adjusting the pH value of the material to 7-9; 10Kg of soybean protein hydrolysate solution (with the content of 50%) is added from a special storage tank; adding 17.5Kg of urea into a urea storage tank; heating the interlayer by steam, and controlling the heating temperature to be 60-90 ℃; the reaction residence time is 30-50 minutes; and cooling to 40 ℃, and pumping the product into a urea-formaldehyde resin storage tank for storage after the product is qualified through inspection.
Claims (7)
1. A synthetic method of urea-formaldehyde resin with ultralow formaldehyde release comprises the following process steps:
A. a pre-condensation reaction zone: comprises a formaldehyde storage tank, a pre-shrinking aldehyde reactor, a plain storage tank and an ammonia storage tank; a50% concentrated formaldehyde aqueous solution is adopted, urea is industrial grade urea, 1/2-1/4 of the usage amount of the formula is added, ammonia water is used for adjusting the pH value to be alkaline, steam is introduced into an interlayer of a reaction kettle for heating, the temperature is controlled to be 60-90 ℃, stirring reaction is carried out for 30-90 min, and urea formaldehyde resin pre-condensed liquid is generated.
B. An addition reaction zone: the device consists of an addition reaction kettle, an auxiliary agent storage tank, a urea storage tank and an ammonia storage tank; adding pre-acetal and an auxiliary agent into a reaction kettle; adding urea twice according to the reaction process, wherein the using amount of the urea is 1/2-2/5 of the total amount; adjusting the pH value to be alkalescent by ammonia water; introducing steam into an interlayer of the reaction kettle for heating, and controlling the temperature to be 60-90 ℃; stirring for reaction, and condensing and refluxing generated steam through a reflux condenser; the reaction residence time is 30-90 minutes.
C. A condensation reaction zone: comprises a formic acid storage tank and a condensation reaction kettle; adding formic acid into the reaction materials, adjusting the pH value of the solution to be acidic by 3-6.5, introducing steam into an interlayer of the reaction kettle, and heating, wherein the temperature is controlled at 60-85 ℃; stirring and reacting, wherein the reaction residence time is 30-90 minutes, and the reaction end point is determined according to a viscosity method or cloud point.
D. A curing reaction zone: consists of an alkaline solution storage tank, a soybean protein hydrolysate storage tank, a urea storage tank and a ripening reaction kettle; adjusting the pH value of the material to be alkaline by using an alkaline solution, wherein the alkaline solution is a 30% sodium hydroxide aqueous solution; adding the soybean protein hydrolysate and the balance of urea, introducing steam into a jacket to heat, stirring and reacting at 60-70 ℃, and keeping the reaction time for 30-60 min.
E. Detection and storage area: the device consists of a product detection device and a urea-formaldehyde resin storage tank; the product detection device is an online detection system, and the qualified product is put into a urea-formaldehyde resin storage tank for later use.
2. The process of claim 1, wherein: in the pre-condensation reaction zone, the urea is of industrial grade, the content of sulfate is less than 0.01 percent, the content of biuret is less than 0.7 percent, and the content of free ammonia is less than 0.015 percent.
3. The process of claim 1, wherein: in the pre-condensation reaction zone, the formaldehyde is in industrial grade, the concentration is more than or equal to 50 percent, and the formic acid is less than 0.1 percent; methanol is less than 1.5 percent, and ferrum is less than 0.0005 percent.
4. The process of claim 1, wherein: in the addition reaction zone, the auxiliary agent is composed of polyvinyl alcohol, melamine or a mixture of the polyvinyl alcohol and the melamine, wherein the polyvinyl alcohol is a 50% aqueous solution, and the type of the polyvinyl alcohol is 1799 or 1788; the alkali liquor is preferably ammonia water solution; the urea is of industrial grade, the content of sulfate is less than 0.01 percent, the content of biuret is less than 0.7 percent, and the content of free ammonia is less than 0.015 percent.
5. The process of claim 1, wherein: a curing reaction zone, wherein the alkali liquor is 30% sodium hydroxide aqueous solution; the soybean protein hydrolysate is a 50% aqueous solution; the urea is of industrial grade, the content of sulfate is less than 0.01 percent, the content of biuret is less than 0.7 percent, and the content of free ammonia is less than 0.015 percent.
6. The process of claim 1, wherein: the soybean hydrolyzed protein has the following quality requirements: the content of sulfate is less than 0.015 percent, the content of free ammonia is less than 0.005 percent, the content of iron is less than 0.0005 percent, and the pH value is 7.5-11.5.
7. The process of claim 1, wherein: in the curing reaction zone, the addition amount of the soybean hydrolyzed protein is more than or equal to 2 percent (100 percent content), the reaction temperature is preferably 50-60 ℃, and the reaction residence time is preferably 20-30 min.
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| CN114214014A (en) * | 2021-12-21 | 2022-03-22 | 广西精典化工新材料有限公司 | Method for synthesizing urea-formaldehyde resin with ultralow formaldehyde release by using soybean protein hydrolysate |
| CN115368525A (en) * | 2022-08-21 | 2022-11-22 | 广西精典化工新材料有限公司 | Method for synthesizing environment-friendly urea-formaldehyde resin by using paraformaldehyde |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114214014A (en) * | 2021-12-21 | 2022-03-22 | 广西精典化工新材料有限公司 | Method for synthesizing urea-formaldehyde resin with ultralow formaldehyde release by using soybean protein hydrolysate |
| CN115368525A (en) * | 2022-08-21 | 2022-11-22 | 广西精典化工新材料有限公司 | Method for synthesizing environment-friendly urea-formaldehyde resin by using paraformaldehyde |
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