Water-based formaldehyde-free adhesive and preparation method thereof

Abstract

The invention relates to the technical field of adhesives, and discloses a water-based formaldehyde-free adhesive. Comprising the following raw materials in parts by weight: 4-6% of polyvinyl alcohol, 3-6% of silica sol, 0.2% of ethylene glycol, 1% of glutinous rice flour, 5-8% of water-soluble starch, 2% of glass fiber powder, 0.2% of starch ether, 0.2-0.3% of a slow drying agent, 0.2% of a preservative, 0.3% of a mildew preventive, 0.1% of a defoaming agent, 0.2% of a penetrant, 0.1% of a diluent, 8-10% of malt syrup, 0.3% of AMP-95 and 0-2% of pure wood fibers. According to the water-based formaldehyde-free adhesive and the preparation method thereof, the water-based formaldehyde-free adhesive adopts non-toxic and harmless raw materials, use of harmful substances such as formaldehyde is avoided, aldehydes are not generated in the preparation and use process, harm to the environment and human bodies is effectively reduced, the environment-friendly standard is met, the requirement of people for healthy life is met, and meanwhile, the water-based formaldehyde-free adhesive has the advantages of being environmentally friendly, safe and reliable. According to the optimized formula, the bonding performance of the adhesive is remarkably improved, bonding is firmer and more durable, and the adhesive is suitable for bonding of various materials such as wood, paper, cloth and plastic and is wide in application range.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to a water-based formaldehyde-free adhesive and a preparation method thereof. Background Art

[0002] Zero-formaldehyde adhesive is an adhesive that does not contain formaldehyde or other harmful substances. In today's society, as people's awareness of health and environmental protection continues to improve, the demand for zero-formaldehyde adhesives is gradually increasing. However, due to a series of technical problems in the preparation process and raw materials of zero-formaldehyde adhesives, its research and development and production are still a major challenge.

[0003] The existing zero-formaldehyde adhesives have the following problems in the preparation process:

[0004] (1) Raw material selection: Zero-formaldehyde adhesives require non-toxic and harmless raw materials and require them to have high bonding properties. Therefore, how to select suitable raw materials is a major challenge;

[0005] (2) Process route: The preparation of zero-formaldehyde adhesives requires the use of an environmentally friendly and efficient process route to minimize energy and material consumption during the production process. However, the existing process route has problems such as low efficiency and insufficient environmental protection.

[0006] (3) Equipment selection: The preparation of zero-formaldehyde adhesives requires the use of equipment that meets environmental protection requirements, such as reactors and separation equipment. The purchase and operation costs of these equipment are high, which is a heavy burden for small and medium-sized enterprises;

[0007] Therefore, we proposed a water-based formaldehyde-free adhesive and a preparation method thereof. Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] In view of the deficiencies in the prior art, the present invention provides a water-based formaldehyde-free adhesive and a preparation method thereof, which has the advantages of reducing harm to the environment and human body, improving product and production efficiency, and also bringing economic benefits to enterprises, and solves the problems of aldehyde substances generated in traditional adhesives, insufficient adhesive performance and environmental problems during use.

[0010] (II) Technical solution

[0011] In order to achieve the above-mentioned purpose of reducing harm to the environment and human body, improving product and production efficiency, and also bringing economic benefit improvement to the enterprise, the present invention provides the following technical scheme: a water-based formaldehyde-free adhesive, comprising the following raw materials in weight proportion: polyvinyl alcohol 4%-6%, silica sol 3%-6%, ethylene glycol 0.2%, glutinous rice flour 1%, water-soluble starch 5%-8%, glass fiber powder 2%, starch ether 0.2%, retarder 0.2-0.3%, preservative 0.2%, mildewproof agent 0.3%, defoamer 0.1%, penetrant 0.2%, diluent 0.1%, maltose syrup 8%-10%, AMP-950.3% and pure wood fiber 0-2%.

[0012] A method for preparing a water-based formaldehyde-free adhesive comprises the water-based formaldehyde-free adhesive and further comprises the following steps:

[0013] S1. Inspection: Quality inspection of purchased raw materials;

[0014] S2. Storage: Classify and store qualified raw materials, keep the environment dry and ventilated, and ensure the stability and safety of the raw materials;

[0015] S3, mixing: weighed water, silica sol, glyoxal are put into a reactor, stirred for ten minutes, then powders (glutinous rice flour, water-soluble starch, glass fiber powder and starch ether) are added, slowly put into the reactor, stirred for twenty minutes, and then defoamer is added to carry out chemical reaction in the reactor. It takes fifty minutes to ensure that all materials are fully reacted in the reactor, and finally liquids (polyvinyl alcohol, slow drying agent, preservative, mildew inhibitor, penetrant, diluent, maltose syrup and AMP-95) are added;

[0016] S4, heating reaction: adding the mixture into a reaction kettle, heating to 80-90° C. under stirring, and maintaining the reaction for 2-4 hours to ensure that all components react fully to obtain a reaction product;

[0017] S5, cooling: cooling the reaction product to room temperature;

[0018] S6. Adding a reinforcing agent: adding pure wood fiber to the cooled reaction product, and then stirring evenly with a high-speed stirrer;

[0019] S7. Filtration: Filter the mixture to remove impurities and obtain a water-based formaldehyde-free adhesive.

[0020] Preferably, the molecular weight of the polyvinyl alcohol is 120,000-180,000.

[0021] Preferably, the SiO2 content of the silica sol is 35%-38%.

[0022] Preferably, the concentration of glyoxal is 38% aqueous solution.

[0023] Preferably, the preservative is sodium benzoate.

[0024] Preferably, the mildew inhibitor is sodium pentachlorophenol.

[0025] Preferably, the penetrant is sodium alkylbenzene sulfonate.

[0026] Preferably, the diluent is pure water.

[0027] (III) Beneficial effects

[0028] Compared with the prior art, the present invention provides a water-based formaldehyde-free adhesive and a preparation method thereof, which has the following beneficial effects:

[0029] 1. The water-based formaldehyde-free adhesive and its preparation method: the water-based formaldehyde-free adhesive adopts non-toxic and harmless raw materials, such as polyvinyl alcohol, silica sol, glutinous rice flour, etc., avoids the use of harmful substances such as formaldehyde, and does not produce aldehyde substances during the preparation and use process, effectively reducing the harm to the environment and human body, meeting environmental protection standards, and meeting people's needs for healthy life. At the same time, the optimized formula significantly improves the bonding performance of the adhesive, making the bonding stronger and more durable, and is suitable for bonding between various materials, such as wood, paper, cloth, plastic, etc., and has a wide range of applications.

[0030] 2. The water-based formaldehyde-free adhesive and its preparation method make the raw material selection of the adhesive more economical and reduce the waste disposal cost, thus bringing improved economic benefits to the enterprise. The optimized production process improves the production efficiency of the adhesive, shortens the production cycle, reduces the production cost, and creates a larger profit margin for the enterprise. In addition, the adhesive of the present invention has high stability, which effectively prevents the adhesive from stratification, precipitation and the like during use, thereby extending its service life and further reducing costs.

[0031] 3. The water-based formaldehyde-free adhesive and its preparation method, the preparation method, process and formula of the adhesive are carefully designed to make it have higher stability, use high molecular polymer as the main raw material to increase the adhesion and weather resistance of the glue, ensure that the glue can maintain good bonding properties under various environmental conditions, introduce special additives, optimize the formula of the glue, improve its storage stability and anti-aging properties, prevent the performance of the glue from deteriorating during long-term storage and use, and extend its service life.

[0032] 4. The water-based formaldehyde-free adhesive and its preparation method. Traditional glue often uses formaldehyde as a cross-linking agent in the production process, which leads to a high formaldehyde emission, which is harmful to human health. The research and development of the zero-formaldehyde adhesive of the present invention aims to control or even eliminate the formaldehyde content in the glue. By optimizing the raw material formula and improving the production process, a formaldehyde-free cross-linking agent is used to replace traditional formaldehyde, thereby reducing or even eliminating the formaldehyde emission, thereby safeguarding people's healthy life. The adhesive of the present invention has excellent bonding properties and environmental protection characteristics, can effectively replace traditional adhesives, and is widely used in various fields to promote the green and sustainable development of the adhesive industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a schematic diagram of the preparation process of the water-based formaldehyde-free adhesive. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention and the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Embodiment 1:

[0036] A water-based formaldehyde-free adhesive comprises the following raw materials in proportion by weight: 4%-6% polyvinyl alcohol, 3%-6% silica sol, 0.2% ethylene glycol, 1% glutinous rice flour, 5%-8% water-soluble starch, 2% glass fiber powder, 0.2% starch ether, 0.2-0.3% retarder, 0.2% preservative, 0.3% mildewproofing agent, 0.1% defoamer, 0.2% penetrant, 0.1% diluent, 8%-10% maltose syrup, 0.3% AMP-95 and 0-2% pure wood fiber.

[0037] A method for preparing a water-based formaldehyde-free adhesive comprises the water-based formaldehyde-free adhesive and further comprises the following steps:

[0038] S1. Inspection: Quality inspection of purchased raw materials;

[0039] S2. Storage: Classify and store qualified raw materials, keep the environment dry and ventilated, and ensure the stability and safety of the raw materials;

[0040] S3, mixing: weighed water, silica sol, glyoxal are put into a reactor, stirred for ten minutes, then powders (glutinous rice flour, water-soluble starch, glass fiber powder and starch ether) are added, slowly put into the reactor, stirred for twenty minutes, and then defoamer is added to carry out chemical reaction in the reactor. It takes fifty minutes to ensure that all materials are fully reacted in the reactor, and finally liquids (polyvinyl alcohol, slow drying agent, preservative, mildew inhibitor, penetrant, diluent, maltose syrup and AMP-95) are added;

[0041] S4, heating reaction: adding the mixture into a reaction kettle, heating to 80-90° C. under stirring, and maintaining the reaction for 2-4 hours to ensure that all components react fully to obtain a reaction product;

[0042] S5, cooling: cooling the reaction product to room temperature;

[0043] S6. Adding a reinforcing agent: adding pure wood fiber to the cooled reaction product, and then stirring evenly with a high-speed stirrer;

[0044] S7. Filtration: Filter the mixture to remove impurities and obtain a water-based formaldehyde-free adhesive.

[0045] Specifically, during the preparation of water-based formaldehyde-free adhesives, the purchased raw materials need to be quality inspected before formal preparation. The quality inspection and acceptance standards for raw materials include:

[0046] Polyvinyl alcohol: Check whether the molecular weight range is between 120,000-180,000 to ensure its solubility and bonding properties;

[0047] Silica sol: Determine whether the SiO2 content is within the range of 35%-38% to ensure its strengthening effect;

[0048] Ethylene glycol: confirm the purity and concentration to avoid impurities affecting the performance of the adhesive;

[0049] Glutinous rice flour, water-soluble starch, glass fiber powder, starch ether: check particle size distribution and purity to ensure uniform mixing and bonding effect;

[0050] Retarder, preservative, mildew preventer, defoamer, penetrant, diluent: check chemical purity and stability to avoid chemical reaction and microbial growth;

[0051] Maltose syrup: Determine the concentration and viscosity to ensure its thickening and bonding effects;

[0052] AMP-95: Check the active ingredient content to ensure its adhesion-promoting effect;

[0053] Pure wood fiber: evaluates fiber length and purity, enhances the mechanical strength of the adhesive.

[0054] Specifically, during the preparation of the water-based formaldehyde-free adhesive, the reaction product obtained after sufficient reaction needs to be cooled to room temperature, and natural cooling is time-consuming. Therefore, the cooling speed of the reaction product can be accelerated by direct cooling or indirect cooling, wherein:

[0055] Direct cooling: Use cooling water or coolant to cool the outer wall of the reactor through a heat exchanger;

[0056] Indirect cooling: A cooling jacket is set inside the reactor and cooling is carried out by circulating coolant.

[0057] Specifically, after obtaining the water-based formaldehyde-free adhesive, it is necessary to conduct necessary quality tests on it, including:

[0058] (1) Physical properties test:

[0059] Viscosity: Use a viscometer to measure the fluidity of the adhesive;

[0060] Color and clarity: Assess the appearance of the product visually or using a colorimeter;

[0061] Solid content: The proportion of solid components is determined by the loss on drying method;

[0062] (2) Chemical performance test:

[0063] pH value: Use a pH meter to measure the acidity or alkalinity of the product;

[0064] Chemical stability: Evaluate the long-term stability of the product through accelerated aging tests;

[0065] Volatile organic compound (VOC) content: ensure that the product meets environmental standards;

[0066] (3) Adhesion performance test:

[0067] Initial adhesion: Use an initial adhesion tester to measure the initial adhesion ability of the adhesive;

[0068] Holding strength: The holding strength test is used to evaluate the long-term adhesion performance of the adhesive.

[0069] Bond strength: Evaluate the bond strength between adhesives and different substrates through tensile shear tests;

[0070] (4) Environmental adaptability test:

[0071] Temperature resistance: evaluate the bonding performance of the product at different temperatures;

[0072] Moisture resistance: Humidity chamber testing is used to evaluate the performance of the product in high humidity environments;

[0073] Lightfastness: simulate ultraviolet radiation to evaluate the product's light aging resistance;

[0074] (5) Safety inspection:

[0075] Toxicity testing: ensure that the product is harmless to the human body;

[0076] Microbiological testing: Ensures that the product is not contaminated by microorganisms during production and storage.

[0077] Specifically, after obtaining the water-based formaldehyde-free adhesive, the process of quality testing includes:

[0078] Step 1: Sample collection:

[0079] Multiple samples were randomly collected from the filtered batch to ensure representativeness;

[0080] Step 2: Sample preparation:

[0081] The collected samples were homogenized under standard conditions to eliminate minor differences between samples;

[0082] Step 3: Physical performance testing:

[0083] Viscosity testing: Use a rotational viscometer to measure the viscosity of the adhesive to ensure it meets product specifications;

[0084] Color and clarity assessment: Visually assess or measure with a colorimeter under standard light sources;

[0085] Step 4: Chemical performance testing:

[0086] pH value determination: Use a pH meter to measure the pH value of the adhesive;

[0087] Solid content determination: The solid content in the adhesive is measured by heating to constant weight;

[0088] Step 5: Adhesion performance test:

[0089] Initial adhesion test: Use an initial adhesion tester to simulate actual bonding conditions and measure initial adhesion;

[0090] Adhesion test: The adhesive is bonded to a standard substrate and its adhesion durability is measured after a certain period of time.

[0091] Bond strength test: Evaluate the bond strength between adhesives and different substrates through tensile shear tests;

[0092] Step 6: Environmental adaptability test:

[0093] Temperature resistance test: Test the bonding performance of the adhesive under different temperature conditions to ensure that it can maintain its performance under extreme temperatures;

[0094] Humidity resistance test: Test the bonding performance of the adhesive in a high humidity environment and evaluate its stability under humid conditions;

[0095] Lightfastness test: simulates lightfastness under ultraviolet irradiation conditions to evaluate the aging resistance of adhesives;

[0096] Step 7: Safety test:

[0097] Toxicity testing: Evaluate the toxicity of adhesives through biological testing;

[0098] Microbiological testing: Detect the microbial content in the adhesive by culture and counting methods;

[0099] Step 8: Data recording and analysis:

[0100] All test data were recorded and analyzed using statistical methods for consistency and trends.

[0101] Embodiment 2:

[0102] Environmental parameters of the zero-aldehyde adhesive prepared by the water-based formaldehyde-free adhesive and the preparation method thereof of the present invention are as follows:

[0103] 1. Temperature range

[0104] Zero-formaldehyde adhesives have a wide temperature application range. At room temperature, i.e., about 25°C, their bond strength and fluidity are optimal. At lower temperatures, the bond strength and fluidity may decrease, which may affect the performance of the adhesive. However, at higher temperatures, the bond strength and fluidity increase, which allows zero-formaldehyde adhesives to maintain good performance even in hot environments. It should be noted that excessively high temperatures may cause excessive bond strength and lead to excessive brittleness of the material.

[0105] 2. Humidity range

[0106] Zero-formaldehyde adhesives also have good adaptability to humidity. In an environment with a relative humidity of about 5%-6%, their bonding strength and fluidity are the best. In a lower humidity environment, the bonding strength may decrease, which may cause the performance of the adhesive to decrease. However, in a higher humidity environment, the bonding strength may increase, which allows it to maintain good performance in a humid environment. It should be noted that excessive humidity may cause the material to absorb too much water, resulting in performance degradation;

[0107] 3. Impact of Light

[0108] Light also has a certain impact on the performance of zero-formaldehyde adhesives. Long-term exposure to ultraviolet rays may cause the adhesive to age and cause its performance to deteriorate. Therefore, long-term exposure to sunlight should be avoided as much as possible during use. Appropriate light can promote the curing reaction and improve the bonding strength. Therefore, the light conditions can be adjusted according to actual needs during use;

[0109] In summary, the water-based formaldehyde-free adhesive and its preparation method use non-toxic and harmless raw materials, such as polyvinyl alcohol, silica sol, glutinous rice flour, etc., avoid the use of harmful substances such as formaldehyde, and do not produce aldehyde substances during the preparation and use process, effectively reducing the harm to the environment and human body, meeting environmental protection standards, and meeting people's needs for healthy life. At the same time, the optimized formula significantly improves the bonding performance of the adhesive, making the bonding stronger and more durable, and is suitable for bonding between various materials, such as wood, paper, cloth, plastic, etc., and has a wide range of applications.

[0110] Moreover, the water-based formaldehyde-free adhesive and its preparation method make the raw material selection of the adhesive more economical and reduce the waste disposal cost, thus bringing improved economic benefits to the enterprise. The optimized production process improves the production efficiency of the adhesive, shortens the production cycle, reduces the production cost, and creates a larger profit margin for the enterprise. In addition, the adhesive of the present invention has high stability, effectively preventing the adhesive from stratification, precipitation and the like during use, thereby extending its service life and further reducing costs.

[0111] In addition, the water-based formaldehyde-free adhesive and its preparation method, the preparation method, process and formula of the adhesive are carefully designed to make it have higher stability, use high molecular polymer as the main raw material to increase the adhesion and weather resistance of the glue, ensure that the glue can maintain good bonding properties under various environmental conditions, introduce special additives, optimize the formula of the glue, improve its storage stability and anti-aging properties, prevent the glue from experiencing performance degradation during long-term storage and use, and extend its service life.

[0112] In addition, the water-based formaldehyde-free adhesive and its preparation method. Traditional glue often uses formaldehyde as a cross-linking agent in the production process, which leads to a high formaldehyde emission, which is harmful to human health. The research and development of the zero-formaldehyde adhesive of the present invention aims to control or even eliminate the formaldehyde content in the glue. By optimizing the raw material formula and improving the production process, a formaldehyde-free cross-linking agent is used to replace traditional formaldehyde, thereby reducing or even eliminating the formaldehyde emission, thereby safeguarding people's healthy life. The adhesive of the present invention has excellent bonding properties and environmental protection characteristics, can effectively replace traditional adhesives, and is widely used in various fields to promote the green and sustainable development of the adhesive industry, and solves the problems of aldehyde substances generated in traditional adhesives, insufficient adhesive performance and environmental problems during use.

[0113] The relevant modules involved in this system are all hardware system modules or functional modules that combine computer software programs or protocols with hardware in the prior art. The computer software programs or protocols involved in the functional modules are themselves technologies that are well known to those skilled in the art and are not improvements of this system. The improvements of this system are the interaction or connection relationships between the modules, that is, improvements to the overall structure of the system to solve the corresponding technical problems to be solved by this system.

[0114] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water-based formaldehyde-free adhesive, characterized in that: The invention comprises the following raw materials in proportion by weight: 4%-6% polyvinyl alcohol, 3%-6% silica sol, 0.2% ethylene glycol, 1% glutinous rice flour, 5%-8% water-soluble starch, 2% glass fiber powder, 0.2% starch ether, 0.2-0.3% retarder, 0.2% preservative, 0.3% mildewproofing agent, 0.1% defoaming agent, 0.2% penetrant, 0.1% diluent, 8%-10% maltose syrup, 0.3% AMP-95 and 0-2% pure wood fiber.

2. A method for preparing a water-based formaldehyde-free adhesive, characterized in that: The method comprises the water-based formaldehyde-free adhesive according to claim 1, further comprising the following steps: S1. Inspection: Quality inspection of purchased raw materials; S2. Storage: Classify and store qualified raw materials, keep the environment dry and ventilated, and ensure the stability and safety of the raw materials; S3, mixing: weighed water, silica sol, glyoxal are put into a reactor, stirred for ten minutes, then powders (glutinous rice flour, water-soluble starch, glass fiber powder and starch ether) are added, slowly put into the reactor, stirred for twenty minutes, and then defoamer is added to carry out chemical reaction in the reactor. It takes fifty minutes to ensure that all materials are fully reacted in the reactor, and finally liquids (polyvinyl alcohol, slow drying agent, preservative, mildew inhibitor, penetrant, diluent, maltose syrup and AMP-95) are added; S4, heating reaction: adding the mixture into a reaction kettle, heating to 80-90° C. under stirring, and maintaining the reaction for 2-4 hours to ensure that all components react fully to obtain a reaction product; S5, cooling: cooling the reaction product to room temperature; S6. Adding a reinforcing agent: adding pure wood fiber to the cooled reaction product, and then stirring evenly with a high-speed mixer; S7. Filtration: Filter the mixture to remove impurities and obtain a water-based formaldehyde-free adhesive.

3. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The molecular weight of the polyvinyl alcohol is 120,000-180,000.

4. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The SiO2 content of the silica sol is 35%-38%.

5. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The concentration of the glyoxal is 38% aqueous solution.

6. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The preservative is sodium benzoate.

7. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The mildew inhibitor is sodium pentachlorophenol.

8. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The penetrant is sodium alkylbenzene sulfonate.

9. The water-based formaldehyde-free adhesive according to claim 1, characterized in that: The diluent is pure water.

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