A bio-based acrylate pressure sensitive adhesive and a method of making the same

Abstract

The application discloses a kind of bio-based acrylate pressure sensitive adhesive and its preparation method, the pressure sensitive adhesive includes terpene derivative monomer, isosorbide derivative monomer, crosslinking agent isosorbide derivative, thermal initiator, photo initiator, solvent and monomer diluent;The preparation method uses the way of thermal initiation to introduce one isosorbide derivative monomer into polymer segment, simultaneously make full use of the other isosorbide derivative byproduct generated as crosslinking agent is added to form pressure sensitive adhesive crosslinking network, constructs semi-IPN network to enhance the comprehensive performance of bio-based pressure sensitive adhesive.In addition, by monomer diluent adjusting prepolymer concentration, ensure continuous synthesis prepolymer.Finally, the biological raw material used in the application has the potential possibility of replacing fossil raw materials, and has the characteristics of environmental friendliness.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pressure-sensitive adhesive, and particularly relates to a bio-based acrylate pressure-sensitive adhesive and a preparation method thereof. BACKGROUND

[0002] Pressure-sensitive adhesive is a kind of adhesive that can adhere to various materials quickly by applying minimal pressure. Its main feature is that the adhesion process does not require water, solvent or heat energy to activate; only pressure is needed to effectively bond. The adhesion of pressure-sensitive adhesive is derived from its polymer structure, which enables it to flow and fill microscopic irregularities when in contact with the target surface, thus forming a firm bond. This type of adhesive has a wide range of applications in label production, healthcare, office automation, electronic device assembly, and automotive and construction industries, and plays a key role in modern society.

[0003] Currently, bio-based acrylate pressure-sensitive adhesives are often cross-linked to form a tight polymer network to improve comprehensive performance. Chinese patent application CN2020111752933.0 discloses a kind of ultraviolet light curing bio-based pressure-sensitive adhesive and its preparation method, which is cross-linked by 1,6-hexanediol diacrylate with double functional groups. Although the addition of this cross-linking agent forms a network structure, it reduces the bio-based content of the pressure-sensitive adhesive. Patent CN201910929850.2 discloses a kind of high bio-based content adhesive and its preparation method, and pressure-sensitive adhesive tape, which specifically includes using UV irradiation method to photo-initiated polymerization of bio-based monomers to prepare pressure-sensitive adhesive. Patent CN202011172933.0 relates to a kind of ultraviolet light curing bio-based pressure-sensitive adhesive, pressure-sensitive adhesive tape and its preparation method, which also uses UV curing method to prepare pressure-sensitive adhesive. However, during the preparation of the prepolymer, the viscosity of the prepolymer needs to be accurately controlled, which is inconvenient for the continuous production of the product. At the same time, the bio-based hard monomers used are similar to common monomers used in polymerization, such as methyl methacrylate and isobornyl methacrylate, and do not expand the application range of bio-based monomers to pressure-sensitive adhesive. SUMMARY

[0004] The present application provides a kind of bio-based acrylate pressure-sensitive adhesive and its preparation method to solve the problems in prior art.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A method for preparing a bio-based acrylic pressure sensitive adhesive, which method introduces a terpene derivative monomer and an isosorbide derivative monomer into a polymer segment using a thermal initiation method, while fully utilizing the produced another isosorbide derivative by-product as a crosslinking agent to form a pressure sensitive adhesive crosslinking network, constructs a semi-IPN network to enhance the comprehensive performance of the bio-based pressure sensitive adhesive. In addition, the monomer diluent is used to adjust the prepolymer concentration to ensure continuous synthesis of the prepolymer. Finally, the bio-based raw materials used in the present application have the potential to replace fossil raw materials and have the characteristics of environmental friendliness.

[0007] Terpenes are a large class of diverse renewable organic compounds in structure. They can be distinguished from other naturally occurring compounds in structure because they are composed of isoprene units. Due to the diversity and high functionality of this structure, the chemical and polymer industry has growing interest in these compounds. They provide a wide range of polymer properties and multifunctional functionalization possibilities. At the same time, it has a longer chain structure, which is an important factor for making the polymer flexible.

[0008] Isosorbide, a carbohydrate that has attracted attention in polymer applications due to its excellent performance, has developed into a commercially available chemical product with the continuous evolution of production technology. It is generated by dehydration reaction of sorbitol as a diol, and its molecular architecture includes two active hydroxyl groups that can be effectively modified as functional monomers. For example, dimethyl isosorbide is commonly used as a solvent in cosmetics, and isosorbide esters can act as surfactants. In addition, due to the strong skeleton structure of isosorbide composed of two furan units, the overall structure has high flexibility, making isosorbide a popular monomer for synthesizing high-performance bio-based polymers. The modified isosorbide derivative monomer is introduced into the acrylic ester segment, which can significantly optimize the mechanical properties of this bio-based pressure sensitive adhesive. At the same time, the crosslinking agent isosorbide derivative can build a crosslinking network to promote the formation of higher shear strength of the bio-based pressure sensitive adhesive.

[0009] A bio-based acrylic pressure sensitive adhesive, according to weight parts, includes: terpene derivative monomer 90-100 parts, isosorbide derivative monomer 0-16 parts (not including 0), thermal initiator 0-0.3 parts (not including 0), photoinitiator 0.5-1 parts, crosslinking agent isosorbide derivative 0-0.2 parts (not including 0), solvent 200-250 parts, monomer diluent 0-50 parts (not including 0);

[0010] The terpene derivative monomer is prepared by modifying terpenes; the isosorbide derivative monomer and the crosslinking agent isosorbide derivative are prepared by modifying isosorbide.

[0011] Preferably, a bio-based acrylate pressure sensitive adhesive, comprising, by weight parts, terpene derivative monomer 90~100 parts by weight, isosorbide derivative monomer 0~16 parts by weight (not including 0), photoinitiator 0.5 parts by weight, crosslinking agent isosorbide 0~0.2 parts by weight (not including 0), solvent 220~230 parts by weight, monomer diluent 50 parts.

[0012] Further, the terpene derivative monomer is tetrahydrolinalyl acrylate;

[0013] The thermal initiator is at least one of organic peroxide, inorganic peroxide, azo, and redox, and further, the thermal initiator is azobisisobutyronitrile and azobisisoheptyl nitrile in azo, and preferably, the thermal initiator is azobisisoheptyl nitrile;

[0014] The solvent is at least one of toluene, acetone, and ethyl acetate, and preferably, the solvent is ethyl acetate;

[0015] The photoinitiator is 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone;

[0016] The monomer diluent is tetrahydrolinalyl acrylate.

[0017] Further, the preparation method of the tetrahydrolinalyl acrylate is as follows:

[0018] Step 101, dissolve tetrahydrolinalyl alcohol in a mixture of triethylamine and anhydrous dichloromethane, then add acryloyl chloride dropwise at 0°C, stir the mixture to obtain a terpene derivative mixture;

[0019] Step 102, after the reaction is completed, quench with distilled water, extract with anhydrous dichloromethane, combine the organic layers, rinse with saturated brine solution, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain a crude product, and separate the crude product by column chromatography to obtain pure monomer tetrahydrolinalyl acrylate.

[0020] Further, in step 101, the amount of tetrahydrolinalyl alcohol is 0.8-1.2 times the amount of acryloyl chloride, preferably 1.2 times; the amount of triethylamine is 1~1.5 times the amount of tetrahydrolinalyl alcohol, preferably 1.5 times; and the amount of anhydrous dichloromethane is 10~15 times the amount of tetrahydrolinalyl alcohol, preferably 10 times;

[0021] In step 101, the rate of adding acryloyl chloride is 0.3mL / h~0.6mL / h, preferably 0.5mL / h; the reaction time is 10h~12h, preferably 12h; and the reaction temperature is 20℃~25℃, preferably 25℃.

[0022] Further, the preparation method of the isosorbide derivative monomer and the crosslinking agent isosorbide derivative is as follows:

[0023] Step 201, dissolve isosorbide in a mixture of triethylamine, anhydrous tetrahydrofuran and anhydrous dichloromethane, then add acryloyl chloride at 0°C, stir the mixture to obtain an isosorbide derivative mixture;

[0024] Step 202, after the reaction is completed, quench with distilled water, extract with anhydrous dichloromethane, combine the organic layers, rinse with a saturated saline solution, dry over anhydrous sodium sulfate, filter and distill under reduced pressure to obtain a crude product, and separate the crude product by column chromatography to obtain the isosorbide derivative monomer and the crosslinking agent isosorbide derivative.

[0025] Further, in step 201, the amount of isosorbide is 1-3 times, preferably 2 times, the amount of acryloyl chloride; the amount of triethylamine is 1-2 times, preferably 1.5 times, the amount of isosorbide; the amount of anhydrous dichloromethane is 10-15 times, preferably 10 times, the amount of isosorbide; and the amount of anhydrous tetrahydrofuran is 1-3 times, preferably 2 times, the amount of isosorbide.

[0026] In step 201, the rate of adding acryloyl chloride is 0.3 mL / h-0.6 mL / h, preferably 0.5 mL / h; the reaction time is 20 h-30 h, preferably 24 h; and the reaction temperature is 20°C-25°C, preferably 25°C.

[0027] A preparation method of a bio-based acrylate pressure-sensitive adhesive, comprising the following steps:

[0028] Step 301, according to the ratio, add the synthesized tetrahydrogeraniol acrylate and the synthesized isosorbide derivative monomer to a solvent, and add a thermal initiator, heat to react to obtain a prepolymer solution;

[0029] Step 302, remove the solvent of the prepolymer solution by distillation under reduced pressure, add a monomer diluent, a photoinitiator and the synthesized crosslinking agent isosorbide derivative, and mix thoroughly to obtain an uncured adhesive solution;

[0030] Step 303, coat the adhesive solution and cure by light irradiation to obtain a bio-based acrylate pressure-sensitive adhesive.

[0031] Further, in step 301, the reaction temperature is 55-65°C, preferably 65°C, and the reaction time is 10-20 h, preferably 12 h.

[0032] In step 302, the amount of monomer diluent added is 30% to 60% of the mass of the prepolymer synthesized in step 301, preferably 50%; the amount of photoinitiator added is 1% to 2% of the mass of the diluent added, preferably 1%; and the amount of crosslinking agent isosorbide derivative added is 0% to 3% of the mass of the diluent.

[0033] In step 303, the glue solution coating thickness is 30 µm to 100 µm, preferably 65 µm; and the glue solution curing parameters are 1500 mJ / cm 2 ~2000 mJ / cm 2 , 6 mW / cm 2 ~ 8 mW / cm 2 , 25°C to 30°C, preferably 2000 mJ / cm 2 , 8 mW / cm 2 , 25°C; and the substrate coated with the glue solution is polyethylene terephthalate.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] 1. The present application introduces terpene derivative monomers into the polymer chain segment, further broadening the application of terpenes in the field of pressure-sensitive adhesives.

[0036] 2. The present application introduces isosorbide derivative monomers into the polymer chain segment, which helps to improve the cohesion and adhesion of the pressure-sensitive adhesive. The crosslinking agent isosorbide derivative is generated synchronously during the synthesis of the isosorbide derivative monomer, which fully utilizes the synthesized product.

[0037] 3. The present application introduces the crosslinking agent isosorbide derivative to construct a semi-IPN crosslinking network structure, which helps to improve the comprehensive performance of the pressure-sensitive adhesive.

[0038] 4. The present application uses light curing technology in the curing stage, which presents extremely high curing rate, greatly reduces the production cost, and significantly improves the output efficiency. In addition, light curing also meets the needs of sustainable development and green production in modern society.

[0039] 5. The present application adjusts the viscosity of the prepolymer by adding monomer diluent, which can ensure the continuity of the prepolymer synthesis.

[0040] 6. The biological raw material used in the present application has the potential to replace fossil raw materials and has the characteristics of environmental friendliness. DETAILED DESCRIPTION

[0041] The present application will be further described below in conjunction with examples.

[0042] A bio-based acrylic ester pressure sensitive adhesive, comprising by weight: terpene derivative monomer 90-100 parts, isosorbide derivative monomer 0-16 parts, thermal initiator 0-0.3 parts, photoinitiator 0.5-1 part, crosslinking agent isosorbide derivative 0-0.2 parts, solvent 200-250 parts, monomer diluent 0-50 parts;

[0043] The terpene derivative monomer is prepared by modifying terpenes; the isosorbide derivative monomer and the crosslinking agent isosorbide derivative are prepared by modifying isosorbide;

[0044] As a preferred solution, a bio-based acrylic ester pressure sensitive adhesive, comprising by weight: terpene derivative monomer 90-100 parts, isosorbide derivative monomer 0-16 parts, photoinitiator 0.5 parts, crosslinking agent isosorbide 0-0.2 parts, solvent 220-230 parts, monomer diluent 50 parts.

[0045] As a preferred solution, the terpene derivative monomer is tetrahydrolinalyl propenoate; the thermal initiator is at least one of organic peroxide, inorganic peroxide, azo, and redox; further, the thermal initiator is azobisisobutyronitrile or azobisisoheptyl nitrile of azo; preferably, the thermal initiator is azobisisoheptyl nitrile; the solvent is at least one of toluene, acetone, and ethyl acetate; preferably, the solvent is ethyl acetate; the photoinitiator is 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone; and the monomer diluent is tetrahydrolinalyl propenoate.

[0046] As a preferred solution, the preparation method of the tetrahydrolinalyl propenoate is as follows:

[0047] Step 101: Dissolve tetrahydrolinalyl alcohol in a mixture of triethylamine and anhydrous dichloromethane, then add acryloyl chloride dropwise at 0°C, stir the mixture to obtain a terpene derivative mixture;

[0048] Step 102: After the reaction is completed, quench with distilled water, extract with anhydrous dichloromethane, combine the organic layers, rinse with a saturated saline solution, dry with anhydrous sodium sulfate, filter, and distill under reduced pressure to obtain a crude product, which is separated by column chromatography to obtain pure monomer tetrahydrolinalyl propenoate.

[0049] As a preferred solution, in step 101, the amount of tetrahydrolinalyl alcohol is 0.8-1.2 times, preferably 1.2 times, the amount of acryloyl chloride; the amount of triethylamine is 1-1.5 times, preferably 1.5 times, the amount of tetrahydrolinalyl alcohol; and the amount of anhydrous dichloromethane is 10-15 times, preferably 10 times, the amount of tetrahydrolinalyl alcohol.

[0050] As a preferred solution, in the step 101, the rate of dropwise addition of acryloyl chloride is 0.3 mL / h~0.6 mL / h, preferably 0.5 mL / h; the reaction time is 10 h~12 h, preferably 12 h; and the reaction temperature is 20℃~25℃, preferably 25℃.

[0051] As a preferred solution, the preparation method of the isosorbide derivative monomer and the crosslinking agent isosorbide derivative is as follows:

[0052] Step 201, dissolve isosorbide in a mixture of triethylamine, anhydrous tetrahydrofuran and anhydrous dichloromethane, then slowly add acryloyl chloride at 0℃, stir the mixture to obtain an isosorbide derivative mixture;

[0053] Step 202, after the reaction is completed, quench with distilled water, extract with anhydrous dichloromethane, combine the organic layers, rinse with a saturated saline solution, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain a crude product, and separate the isosorbide derivative monomer and the crosslinking agent isosorbide derivative by column chromatography.

[0054] As a preferred solution, in the step 201, the amount of isosorbide is 1~3 times, preferably 2 times, the amount of acryloyl chloride; the amount of triethylamine is 1~2 times, preferably 1.5 times, the amount of isosorbide; the amount of anhydrous dichloromethane is 10~15 times, preferably 10 times, the amount of isosorbide; and the amount of anhydrous tetrahydrofuran is 1~3 times, preferably 2 times, the amount of isosorbide.

[0055] As a preferred solution, in the step 201, the rate of dropwise addition of acryloyl chloride is 0.3 mL / h~0.6 mL / h, preferably 0.5 mL / h; the reaction time is 20 h~30 h, preferably 24 h; and the reaction temperature is 20℃~25℃, preferably 25℃.

[0056] A preparation method of a bio-based acrylate pressure-sensitive adhesive, comprising the following steps:

[0057] Step 301, according to the ratio, add the synthesized tetrahydrogeraniol acrylate and the synthesized isosorbide derivative monomer to a solvent, and add a thermal initiator, heat and react to obtain a prepolymer solution;

[0058] Step 302, remove the solvent of the prepolymer solution by distillation under reduced pressure, add a monomer diluent, a photoinitiator and the synthesized crosslinking agent isosorbide derivative, and mix thoroughly to obtain an uncured adhesive solution;

[0059] Step 303, coat the adhesive solution and cure by light irradiation to obtain a bio-based acrylate pressure-sensitive adhesive.

[0060] As a preferred embodiment, in step 301, the reaction temperature is 55~65℃, preferably 65℃, and the reaction time is 10~20h, preferably 12h;

[0061] In step 302, the amount of monomer diluent added is 30% to 60% of the mass of the prepolymer synthesized in step 301, preferably 50%; the amount of photoinitiator added is 1% to 2% of the mass of the added diluent, preferably 1%; and the amount of crosslinking agent isosorbide derivative added is 0% to 3% of the mass of the diluent.

[0062] In step 303, the adhesive coating thickness is 30µm~100µm, preferably 65µm; the adhesive curing parameters are 1500mJ / cm. 2 ~2000mJ / cm 2 6mW / cm 2 ~ 8mW / cm 2 25℃~30℃, preferably 2000mJ / cm 2 8mW / cm 2 The substrate coated with the adhesive solution is polyethylene terephthalate (PET) at 25℃.

[0063] In the following examples, only the optimal options are presented for comparing experimental results for various reaction parameters.

[0064] Example 1

[0065] (1) 15g of tetrahydrogeraniol acrylate was added to 28.2g of ethyl acetate, and 21.9mg of azobisisobutyronitrile was added. The gas inside the bottle was removed by a vacuum pump, followed by purging with high-purity nitrogen. This operation was repeated three times. The reaction was carried out at 65 degrees Celsius for 12 hours to obtain a prepolymer solution.

[0066] (2) After removing ethyl acetate by vacuum distillation of the prepolymer solution, weigh 15g of the prepolymer solution and add 7.5g of tetrahydrogeraniol acrylate and 0.16g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone to obtain uncured bio-based acrylic pressure-sensitive adhesive solution.

[0067] (3) The above adhesive solution was coated to a thickness of 65µm using a coating machine and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0068] Example 2

[0069] (1) 15 g of tetrahydrolinalyl acrylate was added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added, and the removal of gas in the bottle was performed by a vacuum pump, and then purged with high-purity nitrogen, and this operation was repeated three times. The reaction was continued for 12 hours at 65°C to obtain a prepolymer solution.

[0070] (2) After the prepolymer solution was added by removing ethyl acetate by reduced pressure distillation, 15 g of prepolymer glue solution was weighed, and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 35 mg of a crosslinking agent isosorbide derivative were added thereto to obtain a non-cured bio-based acrylic pressure-sensitive adhesive glue solution.

[0071] (3) The above glue solution was coated using a coater at a thickness of 65 µm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0072] Example 3

[0073] (1) 15 g of tetrahydrolinalyl acrylate was added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added, and the removal of gas in the bottle was performed by a vacuum pump, and then purged with high-purity nitrogen, and this operation was repeated three times. The reaction was continued for 12 hours at 65°C to obtain a prepolymer solution.

[0074] (2) After the prepolymer solution was added by removing ethyl acetate by reduced pressure distillation, 15 g of prepolymer glue solution was weighed, and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 35 mg of a crosslinking agent isosorbide derivative were added thereto to obtain a non-cured bio-based acrylic pressure-sensitive adhesive glue solution.

[0075] (3) The above glue solution was coated using a coater at a thickness of 65 µm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0076] Example 4

[0077] (1) 15 g of tetrahydrolinalyl acrylate was added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added, and the removal of gas in the bottle was performed by a vacuum pump, and then purged with high-purity nitrogen, and this operation was repeated three times. The reaction was continued for 12 hours at 65°C to obtain a prepolymer solution.

[0078] (2) After removing the ethyl acetate in the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer solution was weighed and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1- propanone, and 35 mg of a crosslinking agent isosorbide derivative were added to obtain a non-cured bio-based acrylic pressure-sensitive adhesive solution.

[0079] (3) The above solution was coated with a coater to a thickness of 65 µm and cured in an ultraviolet light curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using an ultraviolet light energy meter. The results are shown in Table 1.

[0080] Example 5

[0081] (1) 15 g of tetrahydrolinalyl acrylate and 0.15 g of an isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65°C for 12 hours to obtain a prepolymer solution.

[0082] (2) After removing the ethyl acetate in the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer solution was weighed and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1- propanone, and 35 mg of a crosslinking agent isosorbide derivative were added to obtain a non-cured bio-based acrylic pressure-sensitive adhesive solution.

[0083] (3) The above solution was coated with a coater to a thickness of 65 µm and cured in an ultraviolet light curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using an ultraviolet light energy meter. The results are shown in Table 1.

[0084] Example 6

[0085] (1) 15 g of tetrahydrolinalyl acrylate and 0.15 g of an isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65°C for 12 hours to obtain a prepolymer solution.

[0086] (2) After removing the ethyl acetate in the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer solution was weighed and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1- propanone, and 35 mg of a crosslinking agent isosorbide derivative were added to obtain a non-cured bio-based acrylic pressure-sensitive adhesive solution.

[0087] (3) The above glue solution was coated with a coating machine at a thickness of 65 pm and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0088] Example 7

[0089] (1) 15 g of tetrahydrolinalyl acrylate and 0.5 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane nitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65 °C for 12 hours to obtain a prepolymer solution.

[0090] (2) After removing the ethyl acetate from the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer glue solution was weighed, and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 35 mg of crosslinking agent isosorbide derivative were added to obtain an uncured bio-based acrylic pressure-sensitive adhesive glue solution.

[0091] (3) The above glue solution was coated with a coating machine at a thickness of 65 pm and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0092] Example 8

[0093] (1) 15 g of tetrahydrolinalyl acrylate and 0.5 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane nitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65 °C for 12 hours to obtain a prepolymer solution.

[0094] (2) After removing the ethyl acetate from the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer glue solution was weighed, and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 35 mg of crosslinking agent isosorbide derivative were added to obtain an uncured bio-based acrylic pressure-sensitive adhesive glue solution.

[0095] (3) The above glue solution was coated with a coating machine at a thickness of 65 pm and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0096] Example 9

[0097] (1) 15 g of tetrahydrolinalyl acrylate and 0.5 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane nitrile was added, and the removal of gas in the bottle was performed by a vacuum pump, and then purged with high-purity nitrogen, and this operation was repeated three times. The reaction was continued for 12 hours at 65°C to obtain a prepolymer solution.

[0098] (2) After the prepolymer solution was distilled to remove ethyl acetate, 15 g of prepolymer glue solution was weighed, and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 105 mg of crosslinking agent isosorbide derivative were added to obtain a non-cured bio-based acrylic pressure-sensitive adhesive glue solution.

[0099] (3) The above glue solution was coated with a coating machine at a thickness of 65 µm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0100] Example 10:

[0101] (1) 15 g of tetrahydrolinalyl acrylate and 0.75 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane nitrile was added, and the removal of gas in the bottle was performed by a vacuum pump, and then purged with high-purity nitrogen, and this operation was repeated three times. The reaction was continued for 12 hours at 65°C to obtain a prepolymer solution.

[0102] (2) After the prepolymer solution was distilled to remove ethyl acetate, 15 g of prepolymer glue solution was weighed, and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 105 mg of crosslinking agent isosorbide derivative were added to obtain a non-cured bio-based acrylic pressure-sensitive adhesive glue solution.

[0103] (3) The above glue solution was coated with a coating machine at a thickness of 65 µm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV light energy meter. The results are shown in Table 1.

[0104] Example 11:

[0105] (1) 15 g of tetrahydrolinalyl acrylate and 0.75 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane nitrile was added, and the removal of gas in the bottle was performed by a vacuum pump, and then purged with high-purity nitrogen, and this operation was repeated three times. The reaction was continued for 12 hours at 65°C to obtain a prepolymer solution.

[0106] (2) After removing the ethyl acetate from the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer solution was weighed and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of the photoinitiator 2-methyl-l-(4-methylthiophenyl)-2-morpholinopropionone, and 35 mg of the crosslinking agent isosorbide derivative were added to obtain the uncured bio-based acrylic pressure-sensitive adhesive solution.

[0107] (3) The above solution was coated using a coater at a thickness of 65 pm and cured in an ultraviolet light curing machine to obtain the bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using an ultraviolet light energy meter. The results are shown in Table 1.

[0108] Example 12:

[0109] (1) 15 g of tetrahydrolinalyl acrylate and 0.75 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptane nitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65 °C for 12 hours to obtain a prepolymer solution.

[0110] (2) After removing the ethyl acetate from the prepolymer solution by reduced pressure distillation, 15 g of the prepolymer solution was weighed and 7.5 g of tetrahydrolinalyl acrylate, 0.16 g of the photoinitiator 2-methyl-l-(4-methylthiophenyl)-2-morpholinopropionone, and 105 mg of the crosslinking agent isosorbide derivative were added to obtain the uncured bio-based acrylic pressure-sensitive adhesive solution.

[0111] (3) The above solution was coated using a coater at a thickness of 65 pm and cured in an ultraviolet light curing machine to obtain the bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using an ultraviolet light energy meter. The results are shown in Table 1.

[0112] Table 1 Influence of different contents of terpene derivative monomers, different contents of isosorbide derivative monomers, and different contents of crosslinking agent isosorbide derivative in the prepolymer on the performance test of the pressure-sensitive adhesive

[0113]

[0114] The gel fraction in Table 1 was tested as follows:

[0115] About 0.1 g of the pressure-sensitive adhesive sample from different examples was taken and dissolved in 25 mL of ethyl acetate and left to stand for 24 hours. Then, a 200-mesh copper screen was used to filter the remaining residue. The residue was placed in a well-ventilated environment until the mass tended to be stable;

[0116] The gel fraction in Table 1 is calculated according to the following formula:

[0117] Gel (%) = W b / W n x 100%

[0118] In the formula: Gel-gel fraction; W b is the mass of the pressure-sensitive adhesive residue (g); W n is the mass of the pressure-sensitive adhesive taken (g)

[0119] Peel force test: according to GB / T 2792-2014 standard, the peel force of the pressure-sensitive adhesive is measured;

[0120] Initial adhesion test: according to GB / T 4852-2002 standard, the initial adhesion of the pressure-sensitive adhesive is measured;

[0121] Hold adhesion test: according to GB / T 4851-2014 standard, the hold adhesion of the pressure-sensitive adhesive is measured;

[0122] The results show that the sample of examples 1-3 without the addition of isosorbide derivative monomers has relatively good peel force, but the hold adhesion is poor. The comprehensive mechanical properties of the sample of examples 4-9 with the addition of isosorbide derivative monomers are significantly improved. With the introduction of an appropriate amount of crosslinking agent, the mechanical properties of the pressure-sensitive adhesive are also improved. Therefore, the two isosorbide derivatives play a crucial role in the bio-based pressure-sensitive adhesive system.

[0123] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A bio-based acrylate pressure sensitive adhesive, characterized in that, According to parts by weight including: terpene derivative monomer 90~100 parts, isosorbide derivative monomer 0~16 parts, thermal initiator 0~0.3 parts, photoinitiator 0.5~1 parts, crosslinking agent isosorbide derivative 0~0.2 parts, solvent 200~250 parts, monomer diluent 0~50 parts; The terpene derivative monomer is tetrahydrolinalyl propenoate; The monomer diluent is tetrahydrolinalyl propenoate; The value of the isosorbide derivative monomer, thermal initiator, crosslinking agent isosorbide derivative, monomer diluent is not 0; Among them, the terpene derivative monomer is prepared by modifying terpenes;The isosorbide derivative monomer and the crosslinking agent isosorbide derivative are prepared by modifying isosorbide; The preparation method of the isosorbide derivative monomer and the crosslinking agent isosorbide derivative is as follows: Step 201, dissolve isosorbide in a mixture of triethylamine, anhydrous tetrahydrofuran and anhydrous dichloromethane, then add acryloyl chloride at 0℃, stir the mixture, and obtain an isosorbide derivative mixture; Step 202, after the reaction is completed, quench with distilled water, extract with anhydrous dichloromethane, combine the organic layers, rinse with saturated brine solution, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain a crude product, and separate the crude product by column chromatography to obtain the isosorbide derivative monomer and the crosslinking agent isosorbide derivative.

2. The bio-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: the thermal initiator is azobisdimethylisobutyronitrile; the solvent is at least one of toluene, acetone and ethyl acetate; the photoinitiator is 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone.

3. The bio-based acrylate pressure-sensitive adhesive according to claim 2, characterized in that: The preparation method of the tetrahydrolinalyl propenoate is as follows: Step 101, dissolve tetrahydrolinalyl alcohol in a mixture of triethylamine and anhydrous dichloromethane, then add acryloyl chloride dropwise at 0℃, stir the mixture to obtain a terpene derivative mixture; Step 102, after the reaction is completed, quench with distilled water, extract with anhydrous dichloromethane, combine the organic layers, rinse with saturated brine solution, dry with anhydrous sodium sulfate, filter and distill under reduced pressure to obtain a crude product, and separate the crude product by column chromatography to obtain pure monomer tetrahydrolinalyl propenoate.

4. The bio-based acrylate pressure-sensitive adhesive according to claim 3, characterized in that: in step 101, the amount of tetrahydrolinalyl alcohol is 0.8-1.2 times the amount of acryloyl chloride; the amount of triethylamine is 1~1.5 times the amount of tetrahydrolinalyl alcohol; the amount of anhydrous dichloromethane is 10~15 times the amount of tetrahydrolinalyl alcohol; in step 101, the rate of adding acryloyl chloride is 0.3mL / h~0.6mL / h; the reaction time in step 101 is 10h~12h; the reaction temperature in step 101 is 20℃~25℃.

5. The bio-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: in step 201, the amount of isosorbide is 1~3 times the amount of acryloyl chloride. The amount of triethylamine in step 201 is 1-2 times the amount of isosorbide; The amount of anhydrous dichloromethane in step 201 is 10-15 times the amount of isosorbide; The amount of anhydrous tetrahydrofuran in step 201 is 1-3 times the amount of isosorbide; The rate of acryloyl chloride addition in step 201 is 0.3 mL / h-0.6 mL / h; The reaction time in step 201 is 20 h-30 h; The reaction temperature in step 201 is 20℃-25℃.

6. The method of making a bio-based acrylate pressure sensitive adhesive according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step 301: According to the ratio, the synthesized tetrahydrogeraniol propenoate and the synthesized isosorbide derivative monomer are added to the solvent, and a thermal initiator is added for heating reaction to obtain a prepolymer solution; Step 302: The solvent of the prepolymer solution is removed by reduced pressure distillation, and a monomer diluent, a photoinitiator and a synthesized crosslinking agent isosorbide derivative are added and mixed to obtain an uncured glue solution; Step 303: The glue solution is coated and cured by light irradiation to obtain a bio-based acrylate pressure-sensitive adhesive.

7. The preparation method of the bio-based acrylate pressure-sensitive adhesive according to claim 6, wherein the temperature of the reaction in step 301 is 55-65℃, and the reaction time is 10-20 h.

8. The preparation method of the isosorbide-based bio-based acrylate pressure-sensitive adhesive according to claim 6, wherein the amount of the monomer diluent added in step 302 is 30%-60% of the mass of the prepolymer synthesized in step 301; The amount of the photoinitiator added in step 302 is 1%-2% of the mass of the diluent added; The amount of the crosslinking agent isosorbide derivative added in step 302 is 0%-3% of the mass of the diluent.

9. The preparation method of the isosorbide-based bio-based acrylate pressure-sensitive adhesive according to claim 6, wherein the thickness of the glue solution coated in step 303 is 30 µm-100 µm; The substrate on which the glue solution is coated in step 303 is polyethylene terephthalate. ​ ​ The parameter of the glue solution solidification in step 303 is 1500 mJ / cm 2 ~2000 mJ / cm 2 , 6 mW / cm 2 ~ 8 mW / cm 2 , 25℃~30℃; ​

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