Biomass-based acrylate pressure-sensitive adhesive with high persistent viscosity, pressure-sensitive adhesive tape and preparation method of biomass-based acrylate pressure-sensitive adhesive and pressure-sensitive adhesive tape

Abstract

The invention provides a high-persistent-viscosity biomass-based acrylate pressure-sensitive adhesive, a pressure-sensitive adhesive tape and a preparation method of the high-persistent-viscosity biomass-based acrylate pressure-sensitive adhesive. The biomass-based acrylate pressure-sensitive adhesive and the pressure-sensitive adhesive tape are prepared from the following raw materials in parts by weight: 60 to 80 parts of biomass-based acrylate soft monomer, 10 to 20 parts of biomass-based acrylate hard monomer, 10 to 20 parts of functional monomer, 80 to 120 parts of solvent ethyl acetate, 0.3 to 0.7 part of initiator benzoyl peroxide, 2 to 10 parts of tackifying resin and 0.2 to 1 part of cross-linking agent. The biomass-based acrylate pressure-sensitive adhesive disclosed by the invention has the advantages of simple preparation process, strong holding power, low toxicity and good environmental protection property, and has a good application prospect in the pressure-sensitive adhesive industry.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure-sensitive adhesives, and in particular relates to a high-adhesive biomass-based acrylate pressure-sensitive adhesive and a pressure-sensitive adhesive tape and a preparation method thereof. Background Art

[0002] Pressure-sensitive adhesive is a pressure-sensitive adhesive with self-adhesive properties. It is widely used in food packaging, medical fields, electronics industry, construction and automobile industries due to its easy use, rapid bonding and trace-free peeling. Among them, acrylic pressure-sensitive adhesive has become the most widely used type of adhesive due to its simple composition, high transparency and excellent weather resistance. Acrylic pressure-sensitive adhesive mainly refers to a monomer containing unsaturated carbon-carbon double bonds prepared by free radical polymerization under the action of a catalyst.

[0003] However, the preparation of traditional acrylic pressure-sensitive adhesives mainly relies on non-renewable petrochemical resources, which has exacerbated the contradiction between the supply and demand of petrochemical resources in my country. At the same time, with the increasing awareness of environmental protection, people have higher and higher requirements for the environmental protection and sustainability of adhesives. The environmental pollution problems that may be caused during the preparation and use of traditional acrylic pressure-sensitive adhesives have also restricted their application to a certain extent. In addition, although acrylic pressure-sensitive adhesives have many advantages, their stickiness is often not ideal, which also limits their application in certain occasions where the adhesive state needs to be maintained for a long time.

[0004] Therefore, it is particularly important to seek environmentally friendly acrylic pressure-sensitive adhesives that can reduce the use of petroleum resources and have excellent adhesion. In recent years, with the development and utilization of biomass resources, the use of renewable biomass resources to prepare pressure-sensitive adhesives with excellent performance has attracted people's attention. Summary of the invention

[0005] The present invention solves the problems that the existing acrylic pressure-sensitive adhesive mainly relies on non-renewable petrochemical resources, has unsatisfactory lasting adhesion and poor environmental protection, and proposes a method for preparing a high-tack biomass-based acrylic pressure-sensitive adhesive and a pressure-sensitive adhesive tape using acrylic soft monomers and hard monomers from biomass-based resources. The biomass-based acrylic pressure-sensitive adhesive is not only non-toxic, environmentally friendly and biodegradable, but also can be endowed with excellent lasting adhesion through the reasonable selection and ratio of soft and hard monomers, thereby meeting various application requirements.

[0006] The technical solution adopted by the present invention is: A high-tack biomass-based acrylate pressure-sensitive adhesive comprises the following components in parts by mass: 60-80 parts of a biomass-based acrylate soft monomer, 10-20 parts of a biomass-based acrylate hard monomer, 10-20 parts of a functional monomer, 80-120 parts of a solvent ethyl acetate, and 0.3-0.7 parts of an initiator benzoyl peroxide.

[0007] The biomass-based acrylic acid ester soft monomer includes any one or both of lauryl methacrylate and lauryl acrylate.

[0008] The biomass-based acrylate hard monomer includes any one or more of tetrahydrofurfuryl acrylate and tetrahydrofurfuryl methacrylate.

[0009] The functional monomers include any one or more of acrylic acid, itaconic acid, glycidyl acrylate, and hydroxypropyl methacrylate.

[0010] A high-tack biomass-based acrylate pressure-sensitive adhesive tape, comprising the following components, the following parts are by mass: 200 parts of the biomass-based acrylate pressure-sensitive adhesive according to claim 1, 2-10 parts of a tackifying resin, and 0.2-1 part of a cross-linking agent.

[0011] The tackifying resin is rosin resin.

[0012] The cross-linking agent is aluminum acetylacetonate.

[0013] A method for preparing the above-mentioned high-tack biomass-based acrylate pressure-sensitive adhesive is characterized in that, by mass, 60-80 parts of ethyl acetate and 0.1-0.3 parts of initiator are added to a 500 mL three-necked flask, the temperature is raised to 80°C while stirring, and then 60-80 parts of biomass-based acrylate soft monomers are added, and then 10-20 parts of biomass-based acrylate hard monomers, 0.2-0.4 parts of benzoyl peroxide, 10-20 parts of functional monomers and 20-40 parts of ethyl acetate are slowly added. After the dropwise addition is completed, the reaction is continued at 90°C for 3-5 hours, and the biomass-based acrylate pressure-sensitive adhesive is obtained after cooling.

[0014] The biomass-based acrylate hard monomer, benzoyl peroxide, functional monomer and ethyl acetate are uniformly mixed, and then slowly added to the reaction container by a constant pressure dropping funnel within 80-100 minutes.

[0015] A method for preparing the above-mentioned high-tack biomass-based acrylate pressure-sensitive adhesive tape is characterized in that, by mass, 2-10 parts of tackifying resin and 0.2-1 part of cross-linking agent are added to 200 parts of biomass-based acrylate pressure-sensitive adhesive, and the mixture is stirred evenly. After 15-30 minutes, when the bubbles in the adhesive solution basically disappear, the mixture is coated on a PET release film, and heated in an oven at 90-110°C for 2-3 hours to obtain the biomass-based acrylate pressure-sensitive adhesive tape.

[0016] Compared with the prior art solutions, the present invention has at least the following beneficial effects: 1. Environmentally friendly and sustainable: The soft monomer and hard monomer in the present invention both use acrylate monomers derived from renewable biomass resources, which increases the biomass carbon content of the adhesive and reduces the use of petrochemical raw materials. Therefore, the prepared biomass-based acrylate pressure-sensitive adhesive is non-toxic, environmentally friendly, and biodegradable, showing outstanding environmental sustainability.

[0017] 2. High persistence: The biomass-based soft and hard monomers selected in the present invention have unique chemical structures. By adjusting their types and dosages, and introducing functional monomers such as acrylic acid, itaconic acid, glycidyl acrylate, and hydroxypropyl methacrylate, these functional monomers can not only participate in the polymerization reaction, but also improve the cohesive strength and adhesion performance of the pressure-sensitive adhesive through synergistic effects with other components. Therefore, the biomass-based acrylate pressure-sensitive adhesive prepared by the present invention has excellent persistence, and its persistence can reach more than 400 hours at room temperature.

[0018] 3. Mild process conditions: The biomass-based acrylic pressure-sensitive adhesive developed by the present invention has mild process conditions for preparation, and it is not easy to form residual adhesive. By adding solvents, initiators and monomers in batches, the temperature and monomer concentration during the reaction process can be effectively controlled, promoting a smooth and uniform reaction, thereby improving the quality and performance of the pressure-sensitive adhesive.

[0019] In summary, the present invention provides a biomass-based acrylate pressure-sensitive adhesive and pressure-sensitive tape with high sustained adhesion and environmental sustainability and a method for preparing the same, which solves the problems that the existing acrylate pressure-sensitive adhesive mainly relies on non-renewable petrochemical resources, has unsatisfactory sustained adhesion and poor environmental performance, and shows broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the molecular formula of lauryl methacrylate.

[0021] Figure 2 It is the molecular formula of tetrahydrofurfuryl methacrylate.

[0022] Figure 3 It is the molecular formula of isobornyl methacrylate.

[0023] Figure 4 It is the molecular formula of acrylic acid.

[0024] Figure 5 It is the molecular formula of butyl acrylate. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific examples, which are used to illustrate the present invention but are not limited to the scope of the present invention, and also include any combination of the specific embodiments. The implementation conditions used in the examples can be further adjusted according to the specific experimental environment, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0026] Example 1 Preparation of pressure-sensitive adhesive: By mass, add 60 parts of ethyl acetate and 0.1 parts of benzoyl peroxide into a 500 mL three-necked round-bottom bottle, raise the temperature to 80°C while stirring, then add 60 parts of soft monomer lauryl methacrylate at one time, and use a constant pressure dropping funnel to drop 20 parts of hard monomer tetrahydrofurfuryl methacrylate, 0.2 parts of benzoyl peroxide, 20 parts of acrylic acid and 40 parts of ethyl acetate within 100 min. After the addition is completed, continue to react at 90°C for 3 h, and obtain the biomass-based acrylate pressure-sensitive adhesive after cooling.

[0027] Preparation of pressure-sensitive adhesive tape: Add 2 parts of rosin resin and 0.2 parts of aluminum acetylacetonate to 200 parts of biomass-based acrylate pressure-sensitive adhesive, stir evenly, wait for 15 minutes until the bubbles in the adhesive basically disappear, coat it on a PET release film, and bake it at 90°C for 3 hours to obtain the biomass-based acrylate pressure-sensitive adhesive tape.

[0028] Example 2 Preparation of pressure-sensitive adhesive: By mass, 65 parts of ethyl acetate and 0.1 parts of benzoyl peroxide were added into a 500 mL three-necked round-bottom bottle, and the temperature was raised to 80°C while stirring. Subsequently, 65 parts of soft monomer lauryl methacrylate were added at one time, and 17.5 parts of hard monomer tetrahydrofurfuryl methacrylate, 0.3 parts of benzoyl peroxide, 17.5 parts of acrylic acid and 35 parts of ethyl acetate were added dropwise with a constant pressure dropping funnel within 95 min. After the addition was completed, the reaction was continued at 90°C for 3.5 h, and the biomass-based acrylate pressure-sensitive adhesive was obtained after cooling.

[0029] Preparation of pressure-sensitive adhesive tape: Add 4 parts of rosin resin and 0.4 parts of aluminum acetylacetonate to 200 parts of biomass-based acrylate pressure-sensitive adhesive, stir evenly, wait for 20 minutes until the bubbles in the adhesive basically disappear, coat it on a PET release film, and bake it at 90°C for 3 hours to obtain the biomass-based acrylate pressure-sensitive adhesive tape.

[0030] Example 3 Preparation of pressure-sensitive adhesive: By mass, add 70 parts of ethyl acetate and 0.2 parts of benzoyl peroxide into a 500 mL three-necked round-bottom bottle, heat to 80°C while stirring, then add 70 parts of soft monomer lauryl methacrylate at one time, and use a constant pressure dropping funnel to drop 15 parts of hard monomer tetrahydrofurfuryl methacrylate, 0.3 parts of benzoyl peroxide, 15 parts of acrylic acid and 30 parts of ethyl acetate within 90 min. After the addition is completed, continue to react at 90°C for 4 h, and obtain the biomass-based acrylate pressure-sensitive adhesive after cooling.

[0031] Preparation of pressure-sensitive adhesive tape: Add 6 parts of rosin resin and 0.6 parts of aluminum acetylacetonate to 200 parts of biomass-based acrylate pressure-sensitive adhesive, stir evenly, wait for 25 minutes until the bubbles in the adhesive basically disappear, apply it on a PET release film, and bake it at 100°C for 2.5 hours to obtain the biomass-based acrylate pressure-sensitive adhesive tape.

[0032] Example 4 Preparation of pressure-sensitive adhesive: By mass, add 75 parts of ethyl acetate and 0.2 parts of benzoyl peroxide into a 500 mL three-necked round-bottom bottle, heat to 80°C while stirring, then add 75 parts of soft monomer lauryl methacrylate at one time, and use a constant pressure dropping funnel to drop 12.5 parts of hard monomer tetrahydrofurfuryl methacrylate, 0.4 parts of benzoyl peroxide, 12.5 parts of acrylic acid and 25 parts of ethyl acetate within 85 min. After the addition is completed, continue to react at 90°C for 4.5 h, and obtain a biomass-based acrylate pressure-sensitive adhesive after cooling.

[0033] Preparation of pressure-sensitive adhesive tape: Add 8 parts of rosin resin and 0.8 parts of aluminum acetylacetonate to 200 parts of biomass-based acrylate pressure-sensitive adhesive, stir evenly, wait for 25 minutes until the bubbles in the adhesive basically disappear, coat it on a PET release film, and bake it at 100°C for 2.5 hours to obtain the biomass-based acrylate pressure-sensitive adhesive tape.

[0034] Example 5 Preparation of pressure-sensitive adhesive: By mass, add 80 parts of ethyl acetate and 0.3 parts of benzoyl peroxide into a 500 mL three-necked round-bottom bottle, heat to 80°C while stirring, then add 80 parts of soft monomer lauryl methacrylate at one time, and use a constant pressure dropping funnel to drop 10 parts of hard monomer tetrahydrofurfuryl methacrylate, 0.4 parts of benzoyl peroxide, 10 parts of acrylic acid and 20 parts of ethyl acetate within 80 min. After the addition is completed, continue to react at 90°C for 5 h, and cool to obtain a biomass-based acrylate pressure-sensitive adhesive.

[0035] Preparation of pressure-sensitive adhesive tape: Add 10 parts of rosin resin and 1 part of aluminum acetylacetonate to 200 parts of biomass-based acrylate pressure-sensitive adhesive, stir them evenly, and after the bubbles in the adhesive solution basically disappear after 30 minutes, coat it on a PET release film and bake it at 110°C for 2 hours to obtain the biomass-based acrylate pressure-sensitive adhesive tape.

[0036] Comparative Example 1 Compared with Example 1, this comparative example is different in that the functional monomer acrylic acid is not added, and the other raw materials and processes are the same as those in Example 1.

[0037] Comparative Example 2 Compared with Example 1, the difference between this comparative example and Example 1 is that the hard monomer tetrahydrofurfuryl methacrylate is added all at once, and the soft monomer lauryl methacrylate is slowly added dropwise together with the initiator and the functional monomer. The other raw materials and processes are the same as those in Example 1.

[0038] Comparative Example 3 Compared with Example 1, the difference in this comparative example is that the soft monomer lauryl methacrylate is replaced by butyl acrylate, and the other raw materials and processes are the same as those in Example 1.

[0039] Comparative Example 4 Compared with Example 1, the difference in this comparative example is that the hard monomer tetrahydrofurfuryl methacrylate is replaced by isobornyl methacrylate, and the other raw materials and processes are the same as those in Example 1.

[0040] Comparative Example 5 Compared with Example 1, this comparative example is different in that 100 parts of solvent ethyl acetate are added at one time, and the other raw materials and processes are the same as those in Example 1.

[0041] Comparative Example 6 Compared with Example 1, the difference in this comparative example is that 0.3 parts of the initiator benzoyl peroxide is added all at once, and the other raw materials and processes are the same as those in Example 1.

[0042] Comparative Example 7 The difference between this comparative example and Example 1 is that the monomer, solvent and initiator are directly mixed together at one time for preparation, and are not added in batches according to proportion. The other raw materials and processes are the same as those in Example 1.

[0043] Performance Testing Initial adhesion, lasting adhesion and 180° peel strength tests: tested in accordance with GB / T 4852-2002, GB / T 4851-1998 and GB / T 2792-1998 standards.

[0044] The solid content is determined by the following method: Weigh 1-2 g of the glue sample, place it in a drying oven at 120°C and dry it for three hours, and calculate its solid content after cooling; The results are shown in the table below: From the above table data, it can be seen that the biomass-based acrylate pressure-sensitive adhesives prepared by the method of the present invention in Examples 1-5 have good holding power compared with the comparative example, and the holding power is greater than 400 h. In addition, the soft monomers and hard monomers used are both biomass resources. Therefore, the prepared acrylate pressure-sensitive adhesive has a high biomass carbon content, which conforms to the concept of green environmental protection. At the same time, the preparation conditions are mild. Examples 1-5 use biomass-based soft monomers and hard monomers with unique molecular structures, and introduce functional monomers. The pressure-sensitive adhesives prepared by free radical copolymerization have outstanding holding power.

[0045] From the comparison of the experimental results of Comparative Example 1 and Example 1, it can be seen that without adding the functional monomer acrylic acid, the initial tack and the lasting tack of the pressure-sensitive adhesive prepared in Comparative Example 1 are reduced. This is mainly because the carboxyl group contained in acrylic acid itself can form hydrogen bonds or other forces with the polar groups on the bonded surface, thereby improving the bonding performance, and can cross-link with other monomers to increase the cohesive strength of the pressure-sensitive adhesive, thereby improving the initial tack and the lasting tack of the pressure-sensitive adhesive.

[0046] From the comparison of the experimental results of Comparative Example 2 and Example 1, it can be seen that the pressure-sensitive adhesive prepared by adding the hard monomer all at once and then slowly adding the soft monomer has good initial tack but poor sustained tack. This is mainly because after the hard monomer is added all at once, a harder polymer segment is easily formed in the early stage of the reaction, while the slowly added soft monomer reacts continuously to generate a softer cross-linked network that is entangled on the surface of the hard monomer, making the pressure-sensitive adhesive softer, and the initial tack is improved while the sustained tack is reduced.

[0047] From the comparison of the experimental results of Comparative Example 3 and Example 1, it can be seen that: when lauryl methacrylate is replaced by butyl acrylate, since the proportion of flexible units in the molecular structure of lauryl methacrylate is higher than that of butyl acrylate, the longer-chain flexible units can improve the wettability of the pressure-sensitive adhesive to the substrate, thereby enhancing the adhesion, so that the pressure-sensitive adhesive prepared in Comparative Example 1 has reduced initial tack and sustained tack.

[0048] From the comparison of the experimental results of Comparative Example 4 and Example 1, it can be seen that by replacing tetrahydrofurfuryl methacrylate with isobornyl methacrylate, the tackiness of the pressure-sensitive adhesive prepared in Comparative Example 3 is reduced. This is mainly because compared with isobornyl methacrylate, the tetrahydrofuran group contained in tetrahydrofurfuryl methacrylate has a strong polarity, which can improve the adhesion of the pressure-sensitive adhesive to various substrates, which is beneficial to improving the tackiness of the pressure-sensitive adhesive.

[0049] From the comparison of the experimental results of Comparative Example 5 and Example 1, it can be seen that adding ethyl acetate solvent in batches can control the concentration of each monomer in the reaction, which helps to promote the uniform mixing of soft monomers, hard monomers and functional monomers in the system and the free radical polymerization reaction, thereby making the pressure-sensitive adhesive prepared in the comparative example have lower tack than Example 1.

[0050] From the comparison of the experimental results of Comparative Example 6 and Example 1, it can be seen that: if all the initiators are added in one batch and the concentration of the initiator is too high, free radical polymerization reaction will be induced quickly between the monomers. Too fast polymerization reaction makes the reaction insufficient, and finally leads to a significant decrease in the tackiness and initial adhesion of the pressure-sensitive adhesive.

[0051] From the comparison of the experimental results of Comparative Example 7 and Example 1, it can be seen that when the soft monomer, hard monomer, solvent and initiator are directly mixed all at once for reaction, the concentration of initiator and monomer is too high, the reaction is violent, the mixed system is unstable, and finally gelation occurs, which cannot be used to prepare acrylic pressure-sensitive adhesive tape.

[0052] The performance test results of the examples and the comparative examples show that the biomass-based acrylate pressure-sensitive adhesive prepared by the method of the present invention has excellent performance in terms of sustained adhesion, and the sustained adhesion of the examples exceeds 400 hours, which is significantly better than the comparative examples. In addition, the pressure-sensitive adhesive of the present invention has no residual adhesive phenomenon during use and has a high solid content.

[0053] The beneficial effects brought about by the technology of the present invention are mainly reflected in the following aspects: first, the use of biomass-based resources to replace traditional petrochemical resources significantly improves the environmental friendliness and sustainability of the adhesive; second, by optimizing the ratio of soft and hard monomers with unique structures and introducing functional monomers, the sustained adhesion of the pressure-sensitive adhesive is greatly improved, meeting the application scenarios that require long-term bonding performance; finally, the preparation process conditions are mild and easy to control, ensuring the stability and consistency of product quality.

[0054] In practical applications, the biomass-based acrylate pressure-sensitive adhesive of the present invention can not only be used in multiple fields such as food packaging, medical treatment, electronics, construction and automobiles, but also because of its environmental protection characteristics and excellent bonding properties, it can meet the market's growing demand for high-performance, environmentally friendly adhesives, showing broad market application prospects.

[0055] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-tack biomass-based acrylate pressure-sensitive adhesive, characterized in that: The biomass-based acrylate pressure-sensitive adhesive comprises the following components in parts by mass: 60-80 parts of biomass-based acrylate soft monomer, 10-20 parts of biomass-based acrylate hard monomer, 10-20 parts of functional monomer, 80-120 parts of solvent ethyl acetate, and 0.3-0.7 parts of initiator benzoyl peroxide.

2. The high-tack biomass-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: The biomass-based acrylic acid ester soft monomer includes any one or both of lauryl methacrylate and lauryl acrylate.

3. The high-tack biomass-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: The biomass-based acrylate hard monomer includes any one or more of tetrahydrofurfuryl acrylate and tetrahydrofurfuryl methacrylate.

4. The high-tack biomass-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: The functional monomers include any one or more of acrylic acid, itaconic acid, glycidyl acrylate, and hydroxypropyl methacrylate.

5. A high-adhesive biomass-based acrylic pressure-sensitive adhesive tape, characterized in that: The invention comprises the following components, and the following parts are by mass: 200 parts of the biomass-based acrylate pressure-sensitive adhesive according to claim 1, 2-10 parts of a tackifying resin, and 0.2-1 part of a cross-linking agent.

6. The high-tack biomass-based acrylate pressure-sensitive adhesive tape according to claim 5, characterized in that: The tackifying resin is rosin resin.

7. A high-tack biomass-based acrylate pressure-sensitive adhesive tape according to claim 5, characterized in that: The cross-linking agent is aluminum acetylacetonate.

8. A method for preparing the high-tack biomass-based acrylate pressure-sensitive adhesive as claimed in claim 1, characterized in that: By mass, 60-80 parts of ethyl acetate and 0.1-0.3 parts of initiator are added into a 500 mL three-necked flask, and the temperature is raised to 80°C while stirring. Subsequently, 60-80 parts of biomass-based acrylate soft monomer are added, and then 10-20 parts of biomass-based acrylate hard monomer, 0.2-0.4 parts of benzoyl peroxide, 10-20 parts of functional monomer and 20-40 parts of ethyl acetate are slowly added. After the addition is completed, the reaction is continued at 90°C for 3-5 hours, and the biomass-based acrylate pressure-sensitive adhesive is obtained after cooling.

9. The method for preparing a high-tack biomass-based acrylate pressure-sensitive adhesive according to claim 8, characterized in that: The biomass-based acrylate hard monomer, benzoyl peroxide, functional monomer and ethyl acetate are uniformly mixed, and then slowly added into the reaction container within 80-100 minutes using a constant pressure dropping funnel.

10. A method for preparing the high-adhesive biomass-based acrylate pressure-sensitive adhesive tape as claimed in claim 5, characterized in that: By mass, 2-10 parts of tackifying resin and 0.2-1 part of cross-linking agent are added to 200 parts of biomass-based acrylate pressure-sensitive adhesive, and the mixture is stirred evenly. After 15-30 minutes when the bubbles in the adhesive basically disappear, the mixture is coated on a PET release film and heated in an oven at 90-110°C for 2-3 hours to obtain a biomass-based acrylate pressure-sensitive adhesive tape.

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