Environment-friendly wallpaper adhesive and preparation method thereof
By combining modified bio-based carriers with plant protein dispersions and employing a stepwise preparation process, a stable interfacial cross-linking network was constructed, solving the problems of insufficient adhesion durability and environmental friendliness in wallpaper adhesives, and achieving a balance of high strength, durability, and environmental friendliness.
Patent Information
- Application Number
- CN202512025370.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-03-03
AI Technical Summary
Existing wallpaper adhesives have insufficient bonding durability in long-term use, are prone to interface failure, and are difficult to balance environmental protection and performance.
A modified bio-based carrier and plant protein dispersion were combined, and an interfacial cross-linking network was constructed with a bio-based coupling agent. Environmentally friendly plasticizers, humectants and cross-linking agents were added. A stable adhesive system was formed through stepwise preparation and precise cross-linking curing process.
It improves the bonding strength and water and weather resistance of the adhesive, ensures the environmental performance and long-term stability of the adhesive, solves the problem of insufficient bonding durability, and achieves a balance between environmental protection and performance.
Smart Images
Figure CN121592275A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building decoration materials technology, specifically to an environmentally friendly wallpaper adhesive and its preparation method. Background Technology
[0002] Wallpaper adhesives are a key supporting material in the field of interior decoration and renovation. With the popularization of environmental protection concepts and the increasing demands of consumers for a healthy living environment, traditional solvent-based adhesives are gradually being replaced by water-based adhesives and bio-based adhesives. At present, most bio-based wallpaper adhesives on the market are prepared by modifying single biological raw materials or by simply compounding chemically synthesized resins with biological raw materials. Although they can meet basic bonding needs, they need to withstand the influence of environmental factors such as temperature fluctuations and changes in air humidity in daily home use scenarios, and the requirements for bonding stability are extremely high.
[0003] Existing wallpaper adhesives that rely solely on chemically synthesized resins as the core bonding component may have high initial adhesion, but they suffer from poor interfacial compatibility with biological substrates and wallpaper fibers. Over time, they are prone to interfacial peeling and adhesion weakening due to the effects of humidity and alternating hot and cold temperatures. On the other hand, adhesives made from single biological raw materials have limited molecular structures and weak intermolecular forces, making it difficult to form a stable interfacial cross-linking network. This results in poor adhesion durability and water and weather resistance, making the wallpaper prone to curling and peeling off in humid environments or after prolonged use. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides an environmentally friendly wallpaper adhesive and its preparation method, solving the problems of insufficient bonding durability and easy failure of interfacial bonding caused by existing technical solutions that rely solely on chemically synthesized resins or single biological raw materials.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: an environmentally friendly wallpaper adhesive, comprising the following raw materials in parts by weight: 35-55 parts modified bio-based carrier, 18-28 parts plant protein dispersion, 1-3 parts bio-based coupling agent, 6-12 parts environmentally friendly plasticizer, 2-6 parts crosslinking agent, 0.8-2.5 parts composite preservative, 2-5 parts humectant, 3-6 parts antifreeze agent, and 18-35 parts deionized water; The modified bio-based carrier is a compound of hydroxypropyl starch and sodium carboxymethyl cellulose, with a mass ratio of 1:0.3-0.6.
[0006] By adopting the above technical solution, a technical effect that balances both adhesive performance and environmental performance is achieved by using a modified bio-based carrier as the core binding component, combining it with plant protein dispersion to enhance intermolecular forces, and supplementing it with a bio-based coupling agent to build interfacial cross-linking bridges.
[0007] Preferably, in the modified bio-based carrier, the degree of substitution of hydroxypropyl starch is 0.3-0.5 and the weight-average molecular weight is 200,000-500,000 Da, and the viscosity of sodium carboxymethyl cellulose is 20,000-50,000 mPa·s and the degree of substitution is 0.6-0.8.
[0008] By adopting the above technical solution, hydroxypropyl starch with a specific degree of substitution and molecular weight is used in combination with sodium carboxymethyl cellulose with high viscosity and high degree of substitution. The two form a complementary spatial network structure, which improves the swelling and adhesion of the carrier. Therefore, the modified bio-based carrier has good dispersion stability and excellent compatibility with other components.
[0009] Preferably, the raw material for the plant protein dispersion is soy protein isolate or pea protein isolate; the solid content of the plant protein dispersion is 15-20%, and the particle size distribution is 10-50 μm. The bio-based coupling agent is either a modified soybean oil-based silane coupling agent or a lignin-based glycidyl ether coupling agent. The modified soybean oil-based silane coupling agent has an epoxy value of 0.3-0.5 eq / 100g and a moisture content of 0.1%-0.5%, while the lignin-based glycidyl ether coupling agent has a hydroxyl value of 200-300 mg KOH / g and a molecular weight of 500-1000 Da.
[0010] By adopting the above technical solution, the use of plant protein dispersions with specific solid content and particle size ensures that the protein molecules are fully expanded. Combined with bio-based coupling agents with appropriate active group content, the two ends of the coupling agent bind to the bio-based carrier and the plant protein respectively. Therefore, the adhesive system achieves the technical effect of strong interfacial bonding and dense cross-linked network.
[0011] Preferably, the environmentally friendly plasticizer is a compound of glycerol, polyethylene glycol and tributyl citrate, with a compound mass ratio of 2:1:0.5, and the number-average molecular weight of polyethylene glycol is 380-420 Da; The humectant is trehalose or sodium hyaluronate; the molecular weight of sodium hyaluronate is 10,000-50,000 Da; the antifreeze is a compound of propylene glycol and glycerin in a mass ratio of 1:1; the freezing point of the antifreeze is -30℃ to -20℃.
[0012] By adopting the above technical solution, the adhesive achieves good workability, low-temperature storage stability, and is not prone to drying and cracking due to the use of multi-component environmentally friendly plasticizers to improve the flexibility of the adhesive, the combination of humectants to maintain the moisture balance of the system, and the addition of low-freezing-point compound antifreeze agents to enhance low-temperature resistance. The synergistic effect of each additive does not destroy the core cross-linking structure.
[0013] Preferably, the crosslinking agent is epichlorohydrin, citric acid, or polyglycerol glycidyl ether, wherein the polyglycerol glycidyl ether has a hydroxyl value of 300-500 mg KOH / g, an epoxy value of 0.4-0.6 eq / 100g, and a water content of 0.1%-0.3%, and the composite preservative is a compound of potassium sorbate, natamycin, and ε-polylysine hydrochloride, wherein the compound mass ratio is 3:1:0.5.
[0014] By adopting the above technical solution, the crosslinking agent with moderate activity can react with the active groups of the carrier and protein molecules under mild conditions to form stable chemical crosslinking bonds. Combined with composite preservatives, it can achieve broad-spectrum antibacterial effect without affecting the performance of the adhesive. Therefore, the technical effect of strong adhesive durability, excellent mildew resistance and long shelf life is obtained.
[0015] A method for preparing an environmentally friendly wallpaper adhesive, the method comprising the following steps: S1. Preparation of modified bio-based carrier dispersion: Hydroxypropyl starch and sodium carboxymethyl cellulose were mixed in proportion, deionized water was added, and the mixture was stirred under set temperature and stirring rate conditions to obtain modified bio-based carrier dispersion. S2. Preparation of plant protein dispersion: Add plant protein to deionized water, adjust the pH with sodium hydroxide solution, stir at a constant temperature at a set temperature, and filter through a filter screen after cooling to obtain plant protein dispersion; S3. Construction of the mixed system: Heat the modified bio-based carrier dispersion of S1 to the set temperature, add the plant protein dispersion of S2, stir at the set rate, add the environmentally friendly plasticizer and bio-based coupling agent in sequence, continue stirring, then add the humectant and antifreeze agent, and stir until the system is homogeneous. S4, Crosslinking and Curing Reaction: Add crosslinking agent to the mixture in S3, adjust pH with hydrochloric acid solution, heat to the set temperature, maintain the temperature for reaction, and stir at the set interval during the process; S5. Post-processing molding: Cool the product from S4 to the set temperature, add the composite preservative and stir, add the remaining deionized water to adjust the viscosity, filter through a filter screen to obtain an environmentally friendly wallpaper adhesive.
[0016] By adopting the above technical solution, the stepwise preparation of intermediate products ensures the full dispersion of each component, the stepwise feeding sequence avoids mutual interference between additives, and the precise cross-linking and curing process promotes the formation of network structure. Therefore, the adhesive system achieves the technical effect of uniformity, stability and strong performance controllability.
[0017] Preferably, in step S1, 6-12 parts of deionized water are added, the temperature is set to 40-60℃, the stirring rate is 300-500 r / min, and the stirring time is 30-60 min.
[0018] By adopting the above technical solution, and by using appropriate water addition, temperature and stirring parameters, hydroxypropyl starch and sodium carboxymethyl cellulose are fully swollen and uniformly mixed, avoiding carrier clumping or uneven dispersion. Therefore, the modified bio-based carrier dispersion has good flowability and is free of particulate impurities.
[0019] Preferably, in step S2, the added deionized water is 8-15 parts, the sodium hydroxide solution concentration is 5-10%, the pH is adjusted to 8.5-10.0, the set temperature is 50-70℃, the stirring time is 40-80 min, the filter screen is 100 mesh, and the filtration pressure is 0.1-0.2 MPa.
[0020] By adopting the above technical solution, the pH is adjusted by using a specific concentration of alkaline solution, which promotes the full expansion and dissolution of plant protein peptide chains. Combined with appropriate temperature and stirring time, the dissolution is ensured to be complete. Undissolved impurities are removed by filtration through a 100-mesh filter. Therefore, the plant protein dispersion is clear, transparent and has good stability.
[0021] Preferably, in step S3, the temperature is set to 35-45℃, the stirring rate is 350-450 r / min, the stirring time after adding the plant protein dispersion is 60-90 min, the stirring time after adding the bio-based coupling agent is 40-50 min, and the stirring time after adding the humectant and antifreeze is 20-30 min.
[0022] By adopting the above technical solution, the segmented stirring method first ensures that the carrier and protein dispersion are fully integrated, then gives the coupling agent sufficient reaction time, and finally allows the moisturizing and antifreeze agent to be evenly dispersed, avoiding excessively high local concentrations caused by one-time addition. Therefore, the technical effect of uniform component distribution and sufficient interfacial reaction in the mixed system is achieved.
[0023] Preferably, in step S4, the hydrochloric acid solution concentration is 10%, the pH is adjusted to 6.0-7.5 with an adjustment accuracy of ±0.1, the set temperature is 55-70℃, the heat preservation reaction time is 90-120 min, the temperature fluctuation range is ±2℃, the stirring interval is 10 min every 20 min, and the stirring rate is 300 r / min. In step S5, the temperature is set to 25-30℃, the stirring time is 20-30 min, the viscosity is adjusted to 10000-15000 mPa·s, the viscosity fluctuation range is ±500 mPa·s, the filter screen is 150-200 mesh, the filtration pressure is 0.15-0.3 MPa, and the finished product viscosity is tested using a rotary viscometer at 25℃ and 60 r / min.
[0024] By adopting the above technical solution, the crosslinking reaction is ensured to be mild and sufficient by using precise pH and temperature parameters, intermittent stirring avoids local overheating of the system, the viscosity is adjusted to the construction range in the post-processing stage, and the fineness of the finished product is improved by high-precision filtration. Therefore, the technical effect of high crosslinking density, good workability and stable quality of finished product is obtained.
[0025] This invention provides an environmentally friendly wallpaper adhesive and its preparation method. It has the following beneficial effects: 1. This invention achieves the technical effect of improving the bonding strength and water and environmental stability of adhesives by using a synergistic technical solution of modified bio-based carrier and plant protein compound and bio-based coupling agent interface crosslinking. Compared with the existing technical solutions that rely solely on chemically synthesized resins or single biological raw materials, this invention solves the problems of insufficient bonding durability and easy failure of interface bonding.
[0026] 2. The present invention adopts an integrated process scheme of stepwise addition of additives, temperature-increasing cross-linking curing and segmented purification and filtration, which achieves the technical effect of ensuring the uniformity of the adhesive system and long-term storage stability. Compared with the existing technology of extensive mixing, room temperature reaction or omission of key purification steps, it solves the problems of easy system stratification, crystal precipitation and high risk of mold growth.
[0027] 3. This invention adopts an environmentally friendly formula design with all-bio-based environmentally friendly raw materials and no harmful additives, which achieves the technical effect of non-toxic and environmentally friendly adhesives without compromising core performance. Compared with the existing technology that relies on high VOC solvents, heavy metal preservatives or difficult-to-degrade components, it solves the problem of difficulty in balancing environmental protection and performance. Attached Figure Description
[0028] Figure 1 This is a schematic diagram of the steps in preparing an environmentally friendly wallpaper adhesive according to the present invention. Detailed Implementation
[0029] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] This invention provides an environmentally friendly wallpaper adhesive, comprising the following raw materials in parts by weight: 35-55 parts modified bio-based carrier, 18-28 parts plant protein dispersion, 1-3 parts bio-based coupling agent, 6-12 parts environmentally friendly plasticizer, 2-6 parts crosslinking agent, 0.8-2.5 parts composite preservative, 2-5 parts humectant, 3-6 parts antifreeze agent, and 18-35 parts deionized water; The modified bio-based carrier is a compound of hydroxypropyl starch and sodium carboxymethyl cellulose, with a mass ratio of 1:0.3-0.6.
[0031] In the modified bio-based carrier, the degree of substitution of hydroxypropyl starch is 0.3-0.5 and the weight-average molecular weight is 200,000-500,000 Da, while the viscosity of sodium carboxymethyl cellulose is 20,000-50,000 mPa·s and the degree of substitution is 0.6-0.8.
[0032] The raw material for the plant protein dispersion is soy protein isolate or pea protein isolate; the solid content of the plant protein dispersion is 15-20%, and the particle size distribution is 10-50μm; The bio-based coupling agent is either a modified soybean oil-based silane coupling agent or a lignin-based glycidyl ether coupling agent; The modified soybean oil-based silane coupling agent has an epoxy value of 0.3-0.5 eq / 100g and a moisture content of 0.1%-0.5%, while the lignin-based glycidyl ether coupling agent has a hydroxyl value of 200-300 mg KOH / g and a molecular weight of 500-1000 Da.
[0033] The environmentally friendly plasticizer is a compound of glycerol, polyethylene glycol and tributyl citrate, with a mass ratio of 2:1:0.5. The number average molecular weight of polyethylene glycol is 380-420 Da. The humectant is trehalose or sodium hyaluronate; the molecular weight of sodium hyaluronate is 10,000-50,000 Da, and the antifreeze is a compound of propylene glycol and glycerin in a mass ratio of 1:1; the freezing point of the antifreeze is -30℃ to -20℃.
[0034] The crosslinking agent is epichlorohydrin, citric acid, or polyglycerol glycidyl ether. The polyglycerol glycidyl ether has a hydroxyl value of 300-500 mg KOH / g, an epoxy value of 0.4-0.6 eq / 100g, and a water content of 0.1%-0.3%. The composite preservative is a compound of potassium sorbate, natamycin, and ε-polylysine hydrochloride in a mass ratio of 3:1:0.5.
[0035] Please see the appendix Figure 1 A method for preparing an environmentally friendly wallpaper adhesive, comprising the following steps: S1. Preparation of modified bio-based carrier dispersion: Hydroxypropyl starch and sodium carboxymethyl cellulose were mixed in proportion, deionized water was added, and the mixture was stirred under set temperature and stirring rate conditions to obtain modified bio-based carrier dispersion. In S1, 6-12 parts of deionized water are added, the temperature is set at 40-60℃, the stirring speed is 300-500r / min, and the stirring time is 30-60min.
[0036] S2. Preparation of plant protein dispersion: Add plant protein to deionized water, adjust the pH with sodium hydroxide solution, stir at a constant temperature at a set temperature, and filter through a filter screen after cooling to obtain plant protein dispersion; In S2, 8-15 parts of deionized water are added, the concentration of sodium hydroxide solution is 5-10%, the pH is adjusted to 8.5-10.0, the temperature is set to 50-70℃, the stirring time is 40-80min, the filter screen is 100 mesh, and the filtration pressure is 0.1-0.2MPa.
[0037] S3. Construction of the mixed system: Heat the modified bio-based carrier dispersion of S1 to the set temperature, add the plant protein dispersion of S2, stir at the set rate, add the environmentally friendly plasticizer and bio-based coupling agent in sequence, continue stirring, then add the humectant and antifreeze agent, and stir until the system is homogeneous. In S3, the set temperature is 35-45℃, the stirring rate is 350-450r / min, the stirring time after adding the plant protein dispersion is 60-90min, the stirring time after adding the bio-based coupling agent is 40-50min, and the stirring time after adding the humectant and antifreeze is 20-30min.
[0038] S4, Crosslinking and Curing Reaction: Add crosslinking agent to the mixture in S3, adjust pH with hydrochloric acid solution, heat to the set temperature, maintain the temperature for reaction, and stir at the set interval during the process; In S4, the hydrochloric acid solution concentration is 10%, the pH is adjusted to 6.0-7.5 with an adjustment accuracy of ±0.1, the set temperature is 55-70℃, the heat preservation reaction time is 90-120min, the temperature fluctuation range is ±2℃, the stirring interval is 10min every 20min, and the stirring rate is 300r / min.
[0039] S5. Post-processing and molding: Cool the product from S4 to the set temperature, add the composite preservative and stir, add the remaining deionized water to adjust the viscosity, filter through a filter screen to obtain an environmentally friendly wallpaper adhesive. In S5, the set temperature is 25-30℃, the stirring time is 20-30min, the viscosity is adjusted to 10000-15000mPa·s, the viscosity fluctuation range is ±500mPa·s, the filter screen is 150-200 mesh, the filtration pressure is 0.15-0.3MPa, and the finished product viscosity is tested using a rotary viscometer at 25℃ and 60r / min.
[0040] The following is a description with reference to specific embodiments: Example 1: An environmentally friendly wallpaper adhesive, comprising the following raw materials in parts by weight: The total amount of the following ingredients is as follows: 35 parts modified bio-based carrier, 18 parts plant protein dispersion, 1 part bio-based coupling agent, 6 parts environmentally friendly plasticizer, 2 parts crosslinking agent, 0.8 parts composite preservative, 2 parts humectant, 3 parts antifreeze agent, and 18 parts deionized water.
[0041] The modified bio-based carrier consists of 26.92 parts hydroxypropyl starch and 8.08 parts sodium carboxymethyl cellulose, with a compound mass ratio of 1:0.3. The plant protein dispersion is soybean protein isolate with a solid content of 15% and a particle size distribution of 10 μm. The bio-based coupling agent is a modified soybean oil-based silane coupling agent with an epoxy value of 0.3 eq / 100g and a moisture content of 0.1%. The environmentally friendly plasticizer consists of 3.43 parts glycerol, 1.71 parts polyethylene glycol, and 0.86 parts tributyl citrate, with a compound mass ratio of 2:1:0.5. The number-average molecular weight of polyethylene glycol is 380 Da. The crosslinking agent is epichlorohydrin, and the composite preservative is 0.53 parts potassium sorbic acid, 0.18 parts natamycin and 0.09 parts ε-polylysine hydrochloride, with a compound mass ratio of 3:1:0.5; The humectant is trehalose, and the antifreeze is 1.5 parts propylene glycol and 1.5 parts glycerin, with a compound mass ratio of 1:1. The freezing point is -30℃. Hydroxypropyl starch has a degree of substitution of 0.3 and a weight-average molecular weight of 200,000 Da, while sodium carboxymethyl cellulose has a viscosity of 20,000 mPa·s and a degree of substitution of 0.6.
[0042] A method for preparing an environmentally friendly wallpaper adhesive, comprising the following steps: S1. Preparation of modified bio-based carrier dispersion: Hydroxypropyl starch and sodium carboxymethyl cellulose were mixed at a ratio of 1:0.3, and 6 parts of deionized water were added. The mixture was stirred at 40℃ and 300r / min for 30min to obtain the modified bio-based carrier dispersion. S2. Preparation of plant protein dispersion: Add 8 parts of deionized water to soybean protein isolate, adjust the pH to 8.5 with 5% sodium hydroxide solution, stir at 50℃ for 40 min, cool and filter through a 100-mesh filter at a pressure of 0.1 MPa to obtain plant protein dispersion; S3. Construction of the mixed system: Heat the dispersion of S1 to 35°C, add the plant protein dispersion of S2, stir at 350 r / min for 60 min, add the environmentally friendly plasticizer and bio-based coupling agent in sequence, continue stirring for 40 min, then add the humectant and antifreeze agent, stir for 20 min until the system is homogeneous. S4, Crosslinking and Curing Reaction: Add crosslinking agent to the mixture in S3, adjust the pH to 6.0 with 10% hydrochloric acid solution with an adjustment accuracy of ±0.1, raise the temperature to 55℃ with a temperature fluctuation range of ±2℃, keep the temperature for 90 min, and stir at 300 r / min for 10 min every 20 min during the reaction. S5. Post-processing and molding: Cool the product from S4 to 25°C, add the composite preservative and stir for 20 minutes, add 4 parts of the remaining deionized water, adjust the viscosity to 10000 mPa·s with a viscosity fluctuation range of ±500 mPa·s, filter through a 150-mesh filter at a filtration pressure of 0.15 MPa to obtain an environmentally friendly wallpaper adhesive.
[0043] Example 2: An environmentally friendly wallpaper adhesive, comprising the following raw materials in parts by weight: The total amount of the following ingredients is as follows: 45 parts modified bio-based carrier, 23 parts plant protein dispersion, 2 parts bio-based coupling agent, 9 parts environmentally friendly plasticizer, 4 parts crosslinking agent, 1.5 parts composite preservative, 3.5 parts humectant, 4.5 parts antifreeze agent, and 30 parts deionized water.
[0044] The modified bio-based carrier consists of 31.03 parts hydroxypropyl starch and 13.97 parts sodium carboxymethyl cellulose, with a compound mass ratio of 1:0.45. The plant protein dispersion is pea protein isolate with a solid content of 18% and a particle size distribution of 30 μm. The bio-based coupling agent is a lignin-based glycidyl ether coupling agent with a hydroxyl value of 250 mg KOH / g and a molecular weight of 750 Da. The environmentally friendly plasticizer consists of 5.14 parts glycerol, 2.57 parts polyethylene glycol, and 1.29 parts tributyl citrate, with a compound mass ratio of 2:1:0.5. The number average molecular weight of polyethylene glycol is 400 Da. The crosslinking agent is citric acid, and the composite preservative is 1.0 part potassium sorbate, 0.33 parts natamycin and 0.17 parts ε-polylysine hydrochloride, with a compound mass ratio of 3:1:0.5; The humectant is sodium hyaluronate with a molecular weight of 30,000 Da; the antifreeze is 2.25 parts propylene glycol and 2.25 parts glycerin in a 1:1 mass ratio, with a freezing point of -25℃. Hydroxypropyl starch has a degree of substitution of 0.4 and a weight-average molecular weight of 350,000 Da. Sodium carboxymethyl cellulose has a viscosity of 35,000 mPa·s and a degree of substitution of 0.7.
[0045] A method for preparing an environmentally friendly wallpaper adhesive, comprising the following steps: S1. Preparation of modified bio-based carrier dispersion: Hydroxypropyl starch and sodium carboxymethyl cellulose were mixed at a ratio of 1:0.45, and 9 parts of deionized water were added. The mixture was stirred at 50℃ and 400r / min for 45min to obtain the modified bio-based carrier dispersion. S2. Preparation of plant protein dispersion: Pea protein isolate was added to 12 parts of deionized water, the pH was adjusted to 9.2 with 8% sodium hydroxide solution, and stirred at 60℃ for 60 min. After cooling, it was filtered through a 100-mesh filter at a pressure of 0.15 MPa to obtain the plant protein dispersion. S3. Construction of the mixed system: Heat the dispersion of S1 to 40°C, add the plant protein dispersion of S2, stir at 400 r / min for 75 min, add the environmentally friendly plasticizer and bio-based coupling agent in sequence, continue stirring for 45 min, then add the humectant and antifreeze agent, stir for 25 min until the system is homogeneous. S4, Crosslinking and Curing Reaction: Add crosslinking agent to the mixture in S3, adjust the pH to 6.8 with 10% hydrochloric acid solution with an adjustment accuracy of ±0.1, raise the temperature to 65℃ with a temperature fluctuation range of ±2℃, keep the temperature for 105 min, and stir at 300 r / min for 10 min every 20 min during the reaction. S5. Post-processing and molding: Cool the product from S4 to 28°C, add the composite preservative and stir for 25 minutes, add the remaining 9 parts of deionized water, adjust the viscosity to 12500 mPa·s with a viscosity fluctuation range of ±500 mPa·s, filter through an 180-mesh filter at a filtration pressure of 0.2 MPa to obtain an environmentally friendly wallpaper adhesive.
[0046] Example 3: An environmentally friendly wallpaper adhesive, comprising the following raw materials in parts by weight: The total amount of the following ingredients is as follows: 55 parts modified bio-based carrier, 28 parts plant protein dispersion, 3 parts bio-based coupling agent, 12 parts environmentally friendly plasticizer, 6 parts crosslinking agent, 2.5 parts composite preservative, 5 parts humectant, 6 parts antifreeze agent, and 35 parts deionized water.
[0047] The modified bio-based carrier consists of 34.38 parts hydroxypropyl starch and 20.62 parts sodium carboxymethyl cellulose, with a compound mass ratio of 1:0.6. The plant protein dispersion is pea protein isolate with a solid content of 20% and a particle size distribution of 50 μm. The bio-based coupling agent is a modified soybean oil-based silane coupling agent with an epoxy value of 0.5 eq / 100g and a moisture content of 0.5%. The environmentally friendly plasticizer is composed of 6.86 parts glycerol, 3.43 parts polyethylene glycol and 1.71 parts tributyl citrate, with a compound mass ratio of 2:1:0.5. The number average molecular weight of polyethylene glycol is 420 Da. The crosslinking agent is polyglycerol glycidyl ether, with a hydroxyl value of 500 mg KOH / g, an epoxy value of 0.6 eq / 100g, and a water content of 0.3%. The compound preservative consists of 1.67 parts potassium sorbate, 0.56 parts natamycin, and 0.27 parts ε-polylysine hydrochloride, with a compound mass ratio of 3:1:0.5. The humectant is sodium hyaluronate with a molecular weight of 50,000 Da; the antifreeze is a mixture of 3 parts propylene glycol and 3 parts glycerin in a mass ratio of 1:1, with a freezing point of -20℃. Hydroxypropyl starch has a degree of substitution of 0.5 and a weight-average molecular weight of 500,000 Da. Sodium carboxymethyl cellulose has a viscosity of 50,000 mPa·s and a degree of substitution of 0.8.
[0048] A method for preparing an environmentally friendly wallpaper adhesive, comprising the following steps: S1. Preparation of modified bio-based carrier dispersion: Hydroxypropyl starch and sodium carboxymethyl cellulose were mixed at a ratio of 1:0.6, and 12 parts of deionized water were added. The mixture was stirred at 60℃ and 500r / min for 60min to obtain the modified bio-based carrier dispersion. S2. Preparation of plant protein dispersion: Pea protein isolate was added to 15 parts of deionized water, the pH was adjusted to 10.0 with 10% sodium hydroxide solution, and the mixture was stirred at 70℃ for 80 min. After cooling, the mixture was filtered through a 100-mesh filter at a pressure of 0.2 MPa to obtain the plant protein dispersion. S3. Construction of the mixed system: Heat the dispersion of S1 to 45℃, add the plant protein dispersion of S2, stir at 450r / min for 90min, add the environmentally friendly plasticizer and bio-based coupling agent in sequence, continue stirring for 50min, then add the humectant and antifreeze agent, stir for 30min until the system is homogeneous. S4, Crosslinking and Curing Reaction: Add crosslinking agent to the mixture in S3, adjust the pH to 7.5 with 10% hydrochloric acid solution with an adjustment accuracy of ±0.1, raise the temperature to 70℃ with a temperature fluctuation range of ±2℃, keep the temperature for 120 min, and stir at 300 r / min for 10 min every 20 min during the reaction. S5. Post-processing and molding: Cool the product from S4 to 30°C, add the composite preservative and stir for 30 minutes, add the remaining 8 parts of deionized water, adjust the viscosity to 15000 mPa·s with a viscosity fluctuation range of ±500 mPa·s, filter through a 200-mesh filter at a filtration pressure of 0.3 MPa to obtain an environmentally friendly wallpaper adhesive.
[0049] Comparative Example 1: Unlike Example 2, when constructing the S3 mixed system, a bio-based coupling agent was added first, followed by an environmentally friendly plasticizer. All other process parameters were the same as in Example 2.
[0050] Comparative Example 2: Unlike Example 2, the addition of bio-based coupling agent was omitted in the construction of the S3 mixed system, while the remaining process parameters were the same as in Example 2.
[0051] Comparative Example 3: Unlike Example 2, when constructing the S3 mixed system, the environmentally friendly plasticizer, bio-based coupling agent, humectant and antifreeze were added to the system all at once and stirred, instead of being added in the order of plasticizer, coupling agent, humectant and antifreeze. All other process parameters were the same as in Example 2.
[0052] Comparative Example 4: Unlike Example 2, the S4 crosslinking and curing reaction did not involve a heating operation, but was directly carried out at room temperature of 25°C. All other process parameters were the same as in Example 2.
[0053] Comparative Example 5: Unlike Example 2, the S2 plant protein dispersion was not filtered after preparation and was directly introduced into the S3 mixing system for construction. All other process parameters were the same as in Example 2.
[0054] Comparative Example 6: Unlike Example 2, during the S5 post-processing molding, the remaining deionized water was first added to adjust the viscosity, and then the composite preservative was added and stirred. All other process parameters were the same as in Example 2.
[0055] Table 1. Performance Test Data of Environmentally Friendly Wallpaper Adhesive ; Based on the differences in Examples 1-3, Comparative Examples 1-6, and the performance test data table, it can be seen that the core advantage of this invention stems from the synergistic effect of six key processes: stepwise dispersion of modified bio-based carriers, alkalization and filtration purification of plant proteins, stepwise addition of additives, temperature-induced crosslinking and curing, pre-treatment with preservatives followed by viscosity adjustment, stepwise addition of deionized water, and precise viscosity adjustment. Furthermore, the precise adaptation of parameters for each step significantly and positively impacts the adhesive's bonding strength, water resistance, environmental friendliness, antibacterial properties, and shelf life. It also achieves triple synergistic optimization of bio-based carrier and plant protein compatibility, crosslinking efficiency and low-temperature stability, and additive dispersion uniformity and shelf life.
[0056] Comparative Examples 1-6 all experienced a targeted decline in performance due to the absence or replacement of a single core process: Comparative Example 1 reversed the order of adding plasticizer and coupling agent, resulting in a decrease in the interfacial bonding force between the carrier and the protein, with the bonding strength dropping to 0.85 MPa and the water retention rate being only 78%; Comparative Example 2 omitted the bio-based coupling agent, failing to construct a stable interfacial cross-linking network, resulting in a significant decrease in bonding strength to 0.52 MPa and a drop in mildew resistance to level 2; Comparative Example 3 added all additives at once, leading to uneven dispersion of the system and cross-linking defects, resulting in a bonding strength of 0.70 MPa and a shelf life of only 8 months; Comparative Example 4 eliminated the heating cross-linking and curing process, resulting in insufficient cross-linking due to room temperature reaction, with a bonding strength of only 0.45 MPa and a large amount of crystallization occurring during low-temperature storage; Comparative Example 5 omitted the filtration step of the plant protein dispersion, with residual impurities disrupting the uniformity of the system, leading to impurity precipitation and stratification; Comparative Example 6 reversed the order of adding preservative and adjusting viscosity, resulting in uneven dispersion of the preservative, weakened antibacterial effect, and a shortened shelf life to 9 months, fully demonstrating the indispensability of each process step.
[0057] Examples 1-3 all exhibit excellent performance: VOC content 2.1-2.8 g / L, bonding strength 0.9-1.15 MPa, 90%-95% bonding strength retention rate after 24 hours of immersion in water, mildew resistance grade 0, no crystallization or stratification during storage at -10℃, and shelf life of 12-18 months at room temperature. Example 2 achieves the optimal balance of performance, with a VOC content of 2.1 g / L, bonding strength of 1.15 MPa, a retention rate of 95%, and a shelf life of 18 months, achieving optimal compatibility between environmental friendliness, bonding performance, and storage stability. Example 1 maintains process stability with minimal parameters, suitable for small-scale laboratory preparation and low-cost requirements. Example 3 achieves large-scale production with maximum parameters, balancing capacity and product consistency. Both examples jointly verify the rationality and application flexibility of the parameter range of this invention.
[0058] The compatibility of parameters in each step is crucial for performance assurance: S1 The dispersion temperature and stirring rate of the modified bio-based carrier are matched to the carrier swelling requirements to avoid clumping; S2 The sodium hydroxide concentration and pH value are matched to the stretching of plant protein peptide chains, and the filtration pressure ensures the purity of the dispersion; S3 The mixing temperature and stirring rate are matched to the compatibility of the carrier and protein, and the step-by-step addition sequence ensures uniform dispersion of the additives; S4 The crosslinking temperature and pH value are matched to the reactivity of the crosslinking agent, and the holding time ensures sufficient crosslinking; S5 The cooling temperature and filtration mesh size are matched to the uniformity of the finished product, and the amount of deionized water added is precisely matched to the viscosity requirements; S6 The proportioning parameters of each raw material are matched to synergistically improve environmental protection and bonding performance.
[0059] Example 2 achieves an optimal balance between environmental friendliness, bonding strength, and storage stability through precise adaptation of parameters throughout the entire process; the process collaboration system of Examples 1-3 not only avoids performance loss or cost waste caused by parameter boundaries, but also covers the needs of multiple scenarios such as laboratory research and development, small and medium-sized production, and large-scale mass production.
[0060] In summary, this invention effectively addresses the shortcomings of traditional wallpaper adhesives, such as insufficient environmental friendliness, low bonding strength, poor water and mildew resistance, easy crystallization at low temperatures, and short shelf life. It significantly improves the overall performance of the adhesive. Example 2 has the best cost-effectiveness and potential for large-scale production, and can be directly applied to mass production in the home decoration and building materials industry. The parameter flexibility of Examples 1-3 can be adapted to various scenarios such as laboratory research and development, specialty wallpaper installation, and adhesives for humid environments. It provides an efficient, standardized, environmentally friendly, and replicable technical solution for the high-value utilization of bio-based raw materials in the field of adhesives, and at the same time provides a new path for the industrial production of environmentally friendly wallpaper adhesives.
[0061] Table 2, GB Testing Standards ; VOC content: The reagents and instruments used included ethyl acetate, a gas chromatograph with a flame ionization detector, and a constant temperature water bath. 2.0 g ± 0.01 g of adhesive sample was weighed into a 50 mL stoppered test tube, 20 mL of ethyl acetate was added, and the tube was sealed and placed in a 60 °C water bath for extraction for 30 min, shaking twice during extraction. After cooling, the supernatant was collected and filtered. The column temperature was set to 50 °C initially and held for 2 min, then increased to 200 °C at a rate of 10 °C / min and held for 5 min. The injection port temperature was 230 °C, the detector temperature was 250 °C, and the injection volume was 1 μL. The external standard method was used, with ethyl acetate as the standard substance, for quantification. VOC content (g / L) = (concentration calculated from the standard curve × extraction volume × dilution factor) / sample mass. The result was retained to one decimal place.
[0062] Bond strength: The reagents and instruments used include cement mortar substrate, wallpaper, and a universal testing machine with a range of 0-5kN and a loading rate of 50mm / min. Adhesive is applied according to the actual construction ratio, with an application amount of 0.2g / cm³. 2 The wallpaper was bonded to the cement mortar substrate and rolled back and forth 3 times with a 2kg roller. It was cured for 7 days in a standard environment of 23℃±2℃ and 50%±5% relative humidity. The sample was then fixed in the testing machine fixture and a T-type peel test was performed at a rate of 50mm / min. The maximum peel force was recorded. The bonding strength (MPa) = maximum peel force / bonding area. The result was retained to 2 decimal places.
[0063] 24h immersion bond strength retention rate: The sample preparation method is the same as that for bond strength. The cured sample is completely immersed in distilled water at 23℃±2℃ for 24h. After being taken out, the surface moisture is dried with filter paper and tested immediately. The maximum peel force after immersion is recorded using the same bond strength test method. Retention rate (%) = (bond strength after immersion / bond strength before immersion) × 100. The result is rounded to the nearest integer.
[0064] Mold resistance rating: The reagents and instruments used included potato dextrose agar medium, mold spore suspension, and a constant temperature and humidity incubator. The adhesive was coated onto a cement mortar substrate with a thickness of 0.5 mm. After curing in a standard environment for 7 days, the substrate was sterilized. 0.2 mL of mold spore suspension was evenly inoculated onto the sample surface and placed in an incubator for 7 days. The mold growth was observed and rated from 0 to 4, with 0 and 1 being ≤10%, 2 being ≤30%, 3 being ≤60%, and 4 being >60%.
[0065] -10℃ storage for 72 hours: The instruments used include a low-temperature constant temperature chamber and a glass sealed container. 100g of adhesive sample was weighed into the sealed container to avoid leaving air in the container. The sample was placed in a -10℃ low-temperature chamber for 72 hours. After being taken out, it was restored in an environment of 23℃±2℃ for 2 hours. The sample state was observed, and the presence of crystallization, layering, precipitation, agglomeration, etc. was recorded. The samples were graded as no crystallization and no layering, slight layering, severe layering, and crystal precipitation.
[0066] The storage conditions for room temperature storage shelf life include: 25℃±2℃, relative humidity 50%±5%, sealed and protected from light. The adhesive is dispensed into 500g portions, sealed, and samples are taken periodically to test the bonding strength, appearance, and workability. The qualified standard is that the bonding strength retention rate is ≥80%, there is no mold, no obvious delamination, and good workability. The qualified storage time is recorded, which is the room temperature storage shelf life.
[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An environmentally friendly wallpaper adhesive, characterized in that, The raw materials include the following parts by weight: 35-55 parts modified bio-based carrier, 18-28 parts plant protein dispersion, 1-3 parts bio-based coupling agent, 6-12 parts environmentally friendly plasticizer, 2-6 parts crosslinking agent, 0.8-2.5 parts composite preservative, 2-5 parts humectant, 3-6 parts antifreeze agent, and 18-35 parts deionized water; The modified bio-based carrier is a compound of hydroxypropyl starch and sodium carboxymethyl cellulose, with a mass ratio of 1:0.3-0.
6.
2. The environmentally friendly wallpaper adhesive according to claim 1, characterized in that: In the modified bio-based carrier, the degree of substitution of hydroxypropyl starch is 0.3-0.5 and the weight-average molecular weight is 200,000-500,000 Da, and the viscosity of sodium carboxymethyl cellulose is 20,000-50,000 mPa·s and the degree of substitution is 0.6-0.
8.
3. The environmentally friendly wallpaper adhesive according to claim 1, characterized in that: The raw material for the plant protein dispersion is soy protein isolate or pea protein isolate; the solid content of the plant protein dispersion is 15-20%, and the particle size distribution is 10-50 μm. The bio-based coupling agent is either a modified soybean oil-based silane coupling agent or a lignin-based glycidyl ether coupling agent. The modified soybean oil-based silane coupling agent has an epoxy value of 0.3-0.5 eq / 100g and a moisture content of 0.1%-0.5%, while the lignin-based glycidyl ether coupling agent has a hydroxyl value of 200-300 mg KOH / g and a molecular weight of 500-1000 Da.
4. The environmentally friendly wallpaper adhesive according to claim 1, characterized in that: The environmentally friendly plasticizer is a compound of glycerol, polyethylene glycol and tributyl citrate, with a compound mass ratio of 2:1:0.5, and the number average molecular weight of polyethylene glycol is 380-420 Da. The humectant is trehalose or sodium hyaluronate; the molecular weight of sodium hyaluronate is 10,000-50,000 Da; the antifreeze is a compound of propylene glycol and glycerin in a mass ratio of 1:1; the freezing point of the antifreeze is -30℃ to -20℃.
5. The environmentally friendly wallpaper adhesive according to claim 1, characterized in that: The crosslinking agent is epichlorohydrin, citric acid, or polyglycerol glycidyl ether. The polyglycerol glycidyl ether has a hydroxyl value of 300-500 mg KOH / g, an epoxy value of 0.4-0.6 eq / 100g, and a water content of 0.1%-0.3%. The composite preservative is a compound of potassium sorbate, natamycin, and ε-polylysine hydrochloride in a mass ratio of 3:1:0.
5.
6. A method for preparing an environmentally friendly wallpaper adhesive, characterized in that, The method for using an environmentally friendly wallpaper adhesive according to any one of claims 1-5 includes the following steps: S1. Preparation of modified bio-based carrier dispersion: Hydroxypropyl starch and sodium carboxymethyl cellulose were mixed in proportion, deionized water was added, and the mixture was stirred under set temperature and stirring rate conditions to obtain modified bio-based carrier dispersion. S2. Preparation of plant protein dispersion: Add plant protein to deionized water, adjust the pH with sodium hydroxide solution, stir at a constant temperature at a set temperature, and filter through a filter screen after cooling to obtain plant protein dispersion; S3. Construction of the mixed system: Heat the modified bio-based carrier dispersion of S1 to the set temperature, add the plant protein dispersion of S2, stir at the set rate, add the environmentally friendly plasticizer and bio-based coupling agent in sequence, continue stirring, then add the humectant and antifreeze agent, and stir until the system is homogeneous. S4, Crosslinking and Curing Reaction: Add crosslinking agent to the mixture in S3, adjust pH with hydrochloric acid solution, heat to the set temperature, maintain the temperature for reaction, and stir at the set interval during the process; S5. Post-processing molding: Cool the product from S4 to the set temperature, add the composite preservative and stir, add the remaining deionized water to adjust the viscosity, filter through a filter screen to obtain an environmentally friendly wallpaper adhesive.
7. The method for preparing an environmentally friendly wallpaper adhesive according to claim 6, characterized in that: In step S1, 6-12 parts of deionized water are added, the temperature is set to 40-60℃, the stirring rate is 300-500 r / min, and the stirring time is 30-60 min.
8. The method for preparing an environmentally friendly wallpaper adhesive according to claim 6, characterized in that: In step S2, 8-15 parts of deionized water are added, the concentration of sodium hydroxide solution is 5-10%, the pH is adjusted to 8.5-10.0, the temperature is set to 50-70℃, the stirring time is 40-80 min, the filter screen is 100 mesh, and the filtration pressure is 0.1-0.2 MPa.
9. The method for preparing an environmentally friendly wallpaper adhesive according to claim 6, characterized in that: In step S3, the temperature is set to 35-45℃, the stirring rate is 350-450r / min, the stirring time after adding the plant protein dispersion is 60-90min, the stirring time after adding the bio-based coupling agent is 40-50min, and the stirring time after adding the humectant and antifreeze is 20-30min.
10. The method for preparing an environmentally friendly wallpaper adhesive according to claim 6, characterized in that: In step S4, the hydrochloric acid solution concentration is 10%, the pH is adjusted to 6.0-7.5 with an adjustment accuracy of ±0.1, the set temperature is 55-70℃, the heat preservation reaction time is 90-120 min, the temperature fluctuation range is ±2℃, the stirring interval is 10 min every 20 min, and the stirring rate is 300 r / min. In step S5, the temperature is set to 25-30℃, the stirring time is 20-30 min, the viscosity is adjusted to 10000-15000 mPa·s, the viscosity fluctuation range is ±500 mPa·s, the filter screen is 150-200 mesh, the filtration pressure is 0.15-0.3 MPa, and the finished product viscosity is tested using a rotary viscometer at 25℃ and 60 r / min.