Low-temperature-resistant degradable solvent type acrylate pressure-sensitive adhesive and preparation method thereof

Abstract

The invention discloses a low-temperature-resistant degradable solvent type acrylate pressure-sensitive adhesive and a preparation method thereof, and relates to an acrylate pressure-sensitive adhesive and a preparation method thereof. The invention aims to solve the problem of environmental pollution caused by non-degradability of the traditional pressure-sensitive adhesive. According to the preparation method, an acrylate soft monomer, a hard monomer and a functional monomer are taken as main polymerization raw materials, two degradable functional monomers, namely polylactic acid hydroxyethyl acrylate and polycaprolactone hydroxyethyl acrylate, are introduced, and polyethylene glycol diacrylate is taken as a cross-linking agent. The invention belongs to the technical field of pressure-sensitive adhesives.

Description

TECHNICAL FIELD

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

[0002] Pressure sensitive adhesive (PSA) is a kind of adhesive material that can adhere to the adherend under slight pressure and can be easily peeled off, and is widely used in packaging, labeling, medical, electronic and automotive fields. At present, most of the pressure sensitive adhesives on the market are made of non-renewable petroleum-based polymers (such as acrylate, rubber, silicone). These materials have stable chemical properties and are extremely difficult to degrade in the natural environment. Their products (such as adhesive tape, label, protective film) are usually buried or incinerated as solid waste after use, not only causing waste of resources, but also causing serious "white pollution" and microplastic problems due to their long-term existence.

[0003] With the increasing strictness of global environmental regulations and the enhancement of consumers' environmental awareness, the development of biodegradable green pressure sensitive adhesive has become an important research direction in the field of materials. In the prior art, the main ways to prepare degradable pressure sensitive adhesive include: 1. Introducing degradable polymer segments: Researchers have tried to introduce biodegradable polyesters such as polylactic acid (PLA), polycaprolactone (PCL), and polyhydroxyalkanoate (PHA) into acrylate polymers. Among them, polylactic acid is favored due to its wide source, high transparency and non-toxic degradation products. However, the polylactic acid segment has high rigidity and high crystallinity, resulting in a high glass transition temperature (Tg), which makes the pressure sensitive adhesive prepared therefrom brittle at room temperature and completely loses flexibility and adhesion in low temperature environment (such as below 0℃), which severely limits its application range. Although polycaprolactone (PCL) has excellent low-temperature flexibility (Tg about -60℃), when used alone, the pressure sensitive adhesive prepared therefrom often has insufficient cohesive strength and poor tack, and cannot withstand any substantial load.

[0004] 2. Physical blending and chemical copolymerization: In order to improve the performance, the prior art adopts the methods of physically blending PLA / PCL with acrylate resin or synthesizing PLA-PCL block copolymer. However, physical blending generally has the problem of poor compatibility, which easily leads to phase separation, making the performance of the glue uneven and unstable. Although simple block copolymerization has improved the thermodynamic performance, it is often difficult to accurately control its distribution and role in the network structure of the pressure sensitive adhesive at the molecular level.

[0005] 3. Balance degradable content and performance: a key technical problem is how to determine the optimal amount of degradable components. If the amount is too low, the degradation effect is not significant, and the environmental protection significance is lost; if the amount is too high, the inherent viscoelasticity and bonding performance of the acrylate pressure-sensitive adhesive will be seriously damaged. The prior art lacks a golden ratio that can simultaneously consider degradation efficiency and practical performance.

[0006] 4. Contradiction between degradability and cohesive strength: the most effective method to improve the cohesive strength of pressure-sensitive adhesive is chemical crosslinking. However, the chemical bonds (such as urea bond, amide bond) formed by traditional crosslinking agents (such as polyisocyanate, aziridine, metal salt, etc.) are usually not degradable. These non-degradable crosslinking points will remain after polymer degradation, forming incomplete degradation fragments, or seriously delaying the degradation rate of the overall material, thereby deviating from the original intention of "complete degradation".

[0007] In summary, there is a long-standing core contradiction in the prior art: it is difficult to simultaneously achieve biodegradability, excellent low-temperature resistance and high cohesive strength in a pressure-sensitive adhesive material. Specifically, the degradable pressure-sensitive adhesive based on polylactic acid has poor low-temperature resistance; when trying to improve the low-temperature performance, the cohesive strength or degradation integrity is sacrificed; at the same time, the means to enhance the cohesive force may hinder the degradation process.

[0008] Therefore, there is an urgent need in the art for an innovative technical solution that can break through the above technical barriers through sophisticated molecular structure design and component ratio, and develop a degradable solvent-based acrylate pressure-sensitive adhesive with balanced comprehensive performance and real practical value. SUMMARY

[0009] The present application is to solve the problem of environmental pollution caused by the non-degradability of traditional pressure-sensitive adhesive, and further proposes a low-temperature resistant degradable solvent-based acrylate pressure-sensitive adhesive and a preparation method thereof.

[0010] The technical solution adopted by the present application to solve the above problems is: the mass fraction of each component in the low-temperature resistant degradable solvent-based acrylate pressure-sensitive adhesive is: pressure-sensitive adhesive base 100 parts, degradable crosslinking agent 0.1-0.8 parts, organic solvent 60-80 parts, polylactic acid hydroxyethyl acrylate 20-30 parts, and polycaprolactone hydroxyethyl acrylate 20-40 parts. The pressure-sensitive adhesive base comprises the following raw materials by weight: soft monomer 50-70 parts, hard monomer 20-40 parts, functional monomer 5-8 parts, initiator 0.1-0.5 parts, and organic solvent 60-180 parts.

[0011] Further, the soft monomer is any one or several of ethyl acrylate, butyl acrylate, isooctyl acrylate, and lauryl methacrylate; The hard monomer is any one or several of methyl acrylate, vinyl acetate, tert-butyl acrylate, isobornyl methacrylate.

[0012] Further, the functional monomer is any one or several of acrylic acid, isooctyl acrylate, hydroxybutyl acrylate, glycidyl methacrylate; The initiator is any one or several of dibenzoyl peroxide, azobisisobutyronitrile, azobisisopentyl nitrile, azobisisoheptyl nitrile; The organic solvent is any one or several of ethyl acetate, cyclohexane, toluene, isopropyl alcohol.

[0013] Further, the number average molecular weight of the polylactic acid hydroxyethyl acrylate is 100-500, and the hydroxyl value is 100-300 KOH mg / g; the weight average molecular weight of the polycaprolactone hydroxyethyl acrylate is 200-400, and the hydroxyl value is 200-500 KOH mg / g. The degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200. The number average molecular weight of the polylactic acid hydroxyethyl acrylate is 100-500, and the hydroxyl value is 100-300 KOH mg / g; the weight average molecular weight of the polycaprolactone hydroxyethyl acrylate is 200-400, and the hydroxyl value is 200-500 KOH mg / g; the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0014] The preparation method of the low-temperature resistant degradable solvent type acrylate pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part a and a part b, the organic solvent is added to the part a and stirred in the reaction kettle, the polylactic acid hydroxyethyl acrylate, the polycaprolactone hydroxyethyl acrylate and the organic solvent are added to the part b, and the mixture is stirred and placed in a high-position dropping tank 1; the organic solvent and the initiator are stirred and placed in a high-position dropping tank 2; wherein the part a is 50%-80%, and the part b is 20%-50%; Step 2, then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added to the reaction kettle and continue to heat, and when the reaction in the reaction kettle stops, heating is stopped; Step 3, after waiting for five minutes, the high-position dropping tank 1 starts to drop at a constant speed and is added within 2h, then heat preservation is carried out, and then the mixed solution of the initiator and the organic solvent is added for continuous heat preservation; Step 4, after heat preservation, the mixed solution of polyethylene glycol diacrylate and the organic solvent is added for continuous heat preservation; Step 5, the organic solvent is added, the temperature is lowered, and the mixture is stirred to obtain the degradable solvent type acrylate pressure sensitive adhesive.

[0015] Further, the mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, and the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; The mass of the organic solvent and initiator in step 3 is 5% and 35%, respectively; The mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0016] Further, the stirring speed in steps 1 to 5 is 110r / min.

[0017] Further, the use method of the acrylate pressure-sensitive adhesive is as follows: the pressure-sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and after placing in an oven to dry the solvent, an acrylate pressure-sensitive adhesive tape is obtained.

[0018] Further, the thickness of the coating on the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm, respectively, and the drying temperature and time is 120℃ and 3min, respectively.

[0019] The beneficial effects of the present application are: (1) The perfect unity of degradability and high performance is realized: The present application is not simply physically blending degradable polymers with acrylate, but through chemical synthesis, the polylactic acid (PLA) degradable segment and the polycaprolactone (PCL) flexible segment are directly introduced into the acrylate polymer main chain in the form of graft copolymerization. This molecular level design ensures the perfect compatibility of the degradable component and the matrix resin, avoiding the performance instability caused by phase separation. The final product can effectively degrade under specific composting or natural environmental conditions at the end of the service life, reducing "white pollution" from the source, and maintaining the bonding performance comparable to or even better than traditional petroleum-based pressure-sensitive adhesives during the entire service life.

[0020] (2) The low temperature resistance of the pressure-sensitive adhesive is significantly improved: The present application creatively introduces polycaprolactone hydroxyethyl acrylate (PCL-HEA) as an internal plasticizer and a low-temperature resistant component. PCL has an extremely low glass transition temperature (about -60°C) and excellent flexibility, and its introduction is like embedding "molecular springs" in the polymer network, effectively reducing the embrittlement temperature of the entire colloidal system. This enables the present pressure-sensitive adhesive to maintain good flexibility, tack and hold in low-temperature environments such as cold chain, winter outdoor or cold regions (e.g. -20°C to -35°C), overcoming the core pain points of traditional polylactic acid-based degradable materials, which are prone to embrittlement and adhesion failure at low temperatures.

[0021] (3) High cohesive strength and controllable degradation are achieved simultaneously through degradable crosslinking technology: The present application uses polyethylene glycol diacrylate (PEGDA) as a crosslinking agent, which is a key innovation. PEGDA can efficiently react with polymer chains under the initiation of free radicals to form a stable and uniform three-dimensional network structure. This network structure greatly enhances the cohesive strength, shear resistance and creep resistance of the pressure-sensitive adhesive, enabling it to be applied to heavy-duty bonding or long-term fixation scenarios, effectively avoiding phenomena such as delamination and slippage. More importantly, the PEGDA molecular chain itself is composed of hydrolysable ether and ester bonds, and the crosslinking points formed by it are also degradable. This ensures that the entire crosslinked network can be destroyed during degradation, without forming permanent "inert grids" that hinder degradation like traditional non-degradable crosslinking agents, thus achieving the combination of high strength and complete degradability.

[0022] (4) Provides flexibility in performance adjustment: By adjusting the ratio of polylactic acid hydroxyethyl acrylate to polycaprolactone hydroxyethyl acrylate, the balance between the degradation rate and low-temperature performance of the pressure-sensitive adhesive can be easily adjusted. When faster degradation is required, the proportion of PLA can be appropriately increased; when better low-temperature resistance is required, the proportion of PCL can be appropriately increased. At the same time, by controlling the amount of PEGDA crosslinking agent, the cohesive strength and peel strength of the pressure-sensitive adhesive can be precisely controlled to meet the needs of different application scenarios from disposable convenience to high-performance industrial adhesive tapes.

[0023] In summary, the present application not only provides a specific degradable solvent-based pressure-sensitive adhesive product, but more importantly, it provides an innovative approach to solving the performance bottleneck of degradable materials, successfully breaking the traditional concept of "degradable means low performance", and opening up a new path for the development of high-end, environmentally friendly adhesive products.

[0024] Examples Example 1: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.1 part, organic solvent 60 parts, poly-lactic acid (methyl) acrylic acid hydroxyethyl ester 20 parts, and poly-caprolactone (methyl) acrylic acid hydroxyethyl ester 20 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0025] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisdimethyl isobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the poly-lactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the poly-caprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g; and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0026] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1: the soft monomer, the hard monomer, and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with the poly-lactic acid (methyl) acrylic acid hydroxyethyl ester, the poly-caprolactone (methyl) acrylic acid hydroxyethyl ester, and an organic solvent, and stirred and mixed with an initiator and placed in a high-position dropping tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high-position dropping tank 2; Step 2: then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be heated, and when the explosive polymerization state in the reaction kettle stops, the heating is stopped; Step 3: after the reaction temperature is stable for five minutes, the high-position dropping tank 1 starts to be titrated at a uniform speed and the titration is completed within 2 hours, then a certain time of heat preservation is carried out, and then the mixed liquid of the initiator and the organic solvent is added and continues to be heat preserved; Step 4: after a certain time of heat preservation, the mixed liquid of the polyethylene glycol diacrylate and the organic solvent is added and continues to be heat preserved; Step 5: the organic solvent is added, the temperature is lowered, and stirring is carried out to obtain the degradable solvent type acrylic ester pressure sensitive adhesive.

[0027] The mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; the mass of the organic solvent and initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0028] The stirring speed in the steps is 110 r / min.

[0029] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and after placing in an oven to dry the solvent, the acrylic ester pressure sensitive adhesive tape is obtained.

[0030] The thickness of the coating on the PET release film is 15 μm, the thickness of the TPU base film and the PET base film is 50 μm and 25 μm respectively, and the drying temperature and time is 120℃ and 3 min respectively.

[0031] Example 2: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.2 parts, organic solvent 60 parts, polylactic acid (methyl) acrylic acid hydroxyethyl ester 25 parts, and polycaprolactone (methyl) acrylic acid hydroxyethyl ester 30 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0032] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the polylactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the polycaprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g, and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0033] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part (70%) and a part (30%) in a certain mass ratio, the a part is added with an organic solvent and stirred in a reaction kettle, the b part is added with polylactic acid (meth) acrylic acid hydroxyethyl ester, polycaprolactone (meth) acrylic acid hydroxyethyl ester, organic solvent and initiator are stirred and mixed and placed in a high position drop tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high position drop tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is warmed to 65℃, the initiator and the organic solvent in the high position tank 2 are mixed and added into the reaction kettle and continue to warm, when the reaction kettle is in the state of explosive polymerization, stop heating; Step 3, after waiting for five minutes when the reaction temperature is stable, the high position drop tank 1 starts to be titrated at a uniform speed and is added within 2h, then a certain time of heat preservation is carried out, and then the mixed solution of initiator and organic solvent is added to continue heat preservation; Step 4, after a certain time of heat preservation, the mixed solution of polyethylene glycol diacrylate and organic solvent is added to continue heat preservation; Step 5, organic solvent is added, cooled, stirred to obtain a degradable solvent type acrylate pressure sensitive adhesive.

[0034] The mass of the organic solvent added in the a part in step 1 is 40%, the mass of the organic solvent and the initiator added in the b part high position tank 1 is 30% and 50%, the mass of the organic solvent and the initiator added in the high position tank 2 is 10% and 15%; the mass of the organic solvent and the initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0035] The stirring speed in the steps is 110r / min.

[0036] The use method of the acrylate pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, placed in an oven to dry the solvent, then the acrylate pressure sensitive adhesive tape is obtained.

[0037] The thickness of the coating on the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the drying temperature and time is 120℃ and 3min respectively.

[0038] Example 3: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.3 parts, organic solvent 60 parts, poly-lactic acid (methyl) acrylic acid hydroxyethyl ester 30 parts, and poly-caprolactone (methyl) acrylic acid hydroxyethyl ester 40 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0039] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisdimethyl isobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the poly-lactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the poly-caprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g; and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0040] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1: the soft monomer, the hard monomer, and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with the poly-lactic acid (methyl) acrylic acid hydroxyethyl ester, the poly-caprolactone (methyl) acrylic acid hydroxyethyl ester, and an organic solvent, and the initiator is mixed and placed in a high-position dropping tank 1; the organic solvent and the initiator are mixed and placed in a high-position dropping tank 2; Step 2: then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be heated, and when the reaction in the reaction kettle stops, heating is stopped; Step 3: after the reaction temperature is stable for five minutes, the high-position dropping tank 1 starts to be titrated at a uniform speed and the titration is completed within 2 hours, then a certain time of heat preservation is carried out, and then the mixed solution of the initiator and the organic solvent is added and continues to be heat preserved; Step 4: after a certain time of heat preservation, the mixed solution of the polyethylene glycol diacrylate and the organic solvent is added and continues to be heat preserved; Step 5: the organic solvent is added, the temperature is lowered, and stirring is carried out to obtain the degradable solvent type acrylic ester pressure sensitive adhesive.

[0041] The mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; the mass of the organic solvent and initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0042] The stirring speed in the steps is 110 r / min.

[0043] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and after placing in an oven to dry the solvent, the acrylic ester pressure sensitive adhesive tape is obtained.

[0044] The thickness of the coating on the PET release film is 15 μm, the thickness of the TPU base film and the PET base film is 50 μm and 25 μm respectively, and the drying temperature and time is 120℃ and 3 min respectively.

[0045] Example 3: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.2 parts, organic solvent 60 parts, poly lactic acid (methyl) acrylic acid hydroxyethyl ester 20 parts, and poly caprolactone (methyl) acrylic acid hydroxyethyl ester 20 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0046] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the poly lactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the poly caprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g, and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0047] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part (70%) and a part (30%) in a certain mass ratio, the a part is added with an organic solvent and stirred in a reaction kettle, the b part is added with polylactic acid (meth) acrylic acid hydroxyethyl ester, polycaprolactone (meth) acrylic acid hydroxyethyl ester, organic solvent and initiator are stirred and mixed and placed in a high position drop tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high position drop tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is warmed to 65℃, the initiator and the organic solvent in the high position tank 2 are mixed and added into the reaction kettle and continue to warm, when the reaction kettle is in the state of explosive polymerization, stop heating; Step 3, after waiting for five minutes when the reaction temperature is stable, the high position drop tank 1 starts to be titrated at a uniform speed and is added within 2h, then a certain time of heat preservation is carried out, and then the mixed solution of initiator and organic solvent is added to continue heat preservation; Step 4, after a certain time of heat preservation, the mixed solution of polyethylene glycol diacrylate and organic solvent is added to continue heat preservation; Step 5, organic solvent is added, cooled, stirred to obtain a degradable solvent type acrylate pressure sensitive adhesive.

[0048] The mass of the organic solvent added in the a part in step 1 is 40%, the mass of the organic solvent and the initiator added in the b part high position tank 1 is 30% and 50%, the mass of the organic solvent and the initiator added in the high position tank 2 is 10% and 15%; the mass of the organic solvent and the initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0049] The stirring speed in the steps is 110r / min.

[0050] The use method of the acrylate pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, placed in an oven to dry the solvent, then the acrylate pressure sensitive adhesive tape is obtained.

[0051] The thickness of the coating on the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the drying temperature and time is 120℃ and 3min respectively.

[0052] Example 5: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.1 part, organic solvent 60 parts, polylactic acid (methyl) acrylic acid hydroxyethyl ester 25 parts, and polycaprolactone (methyl) acrylic acid hydroxyethyl ester 30 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0053] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisdimethyl isobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the polylactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the polycaprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g, and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0054] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with polylactic acid (methyl) acrylic acid hydroxyethyl ester, polycaprolactone (methyl) acrylic acid hydroxyethyl ester and an organic solvent, and stirred and mixed with an initiator and placed in a high-position dropping tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high-position dropping tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is warmed to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be warmed, and when the explosive polymerization state in the reaction kettle stops, the heating is stopped; Step 3, after the reaction temperature is stable for five minutes, the high-position dropping tank 1 starts to be titrated at a uniform speed and the titration is completed within 2h, then a certain time of heat preservation is carried out, and then the mixed liquid of the initiator and the organic solvent is added for further heat preservation; Step 4, after a certain time of heat preservation, the mixed liquid of polyethylene glycol diacrylate and organic solvent is added for further heat preservation; Step 5, the organic solvent is added, the temperature is lowered, and the mixture is stirred to obtain a degradable solvent type acrylic ester pressure sensitive adhesive.

[0055] The mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; the mass of the organic solvent and initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0056] The stirring speed in the steps is 110 r / min.

[0057] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and after placing in an oven to dry the solvent, the acrylic ester pressure sensitive adhesive tape is obtained.

[0058] The thickness of the coating on the PET release film is 15 μm, the thickness of the TPU base film and the PET base film is 50 μm and 25 μm respectively, and the drying temperature and time is 120℃ and 3 min respectively.

[0059] Example 6: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.2 parts, organic solvent 60 parts, poly lactic acid (methyl) acrylic acid hydroxyethyl ester 30 parts, and poly caprolactone (methyl) acrylic acid hydroxyethyl ester 30 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0060] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the poly lactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the poly caprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g, and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0061] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part (70%) and a part (30%) in a certain mass ratio, the a part is added with an organic solvent and stirred in a reaction kettle, the b part is added with polylactic acid (meth) acrylic acid hydroxyethyl ester, polycaprolactone (meth) acrylic acid hydroxyethyl ester, organic solvent and initiator are stirred and mixed and placed in a high position drop tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high position drop tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is warmed to 65℃, the initiator and the organic solvent in the high position tank 2 are mixed and added into the reaction kettle and continue to warm, when the reaction kettle is in the state of explosive polymerization, stop heating; Step 3, after waiting for five minutes when the reaction temperature is stable, the high position drop tank 1 starts to be titrated at a uniform speed and is added within 2h, then a certain time of heat preservation is carried out, and then the mixed solution of initiator and organic solvent is added to continue heat preservation; Step 4, after a certain time of heat preservation, the mixed solution of polyethylene glycol diacrylate and organic solvent is added to continue heat preservation; Step 5, organic solvent is added, cooled, stirred to obtain a degradable solvent type acrylate pressure sensitive adhesive.

[0062] The mass of the organic solvent added in the a part in step 1 is 40%, the mass of the organic solvent and the initiator added in the b part high position tank 1 is 30% and 50%, the mass of the organic solvent and the initiator added in the high position tank 2 is 10% and 15%; the mass of the organic solvent and the initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0063] The stirring speed in all the steps is 110r / min.

[0064] The use method of the acrylate pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, placed in an oven to dry the solvent, then the acrylate pressure sensitive adhesive tape is obtained.

[0065] The thickness of the coating on the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the drying temperature and time is 120℃ and 3min respectively.

[0066] Example 7: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.3 parts, organic solvent 60 parts, poly-lactic acid (methyl) acrylic acid hydroxyethyl ester 25 parts, and poly-caprolactone (methyl) acrylic acid hydroxyethyl ester 40 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0067] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisdimethyl isobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the poly-lactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the poly-caprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g; and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0068] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1: the soft monomer, the hard monomer, and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with the poly-lactic acid (methyl) acrylic acid hydroxyethyl ester, the poly-caprolactone (methyl) acrylic acid hydroxyethyl ester, and an organic solvent, and the initiator is mixed and placed in a high-position dropping tank 1; the organic solvent and the initiator are mixed and placed in a high-position dropping tank 2; Step 2: then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be heated, and when the reaction in the reaction kettle stops, heating is stopped; Step 3: after the reaction temperature is stable for five minutes, the high-position dropping tank 1 starts to be titrated at a uniform speed and the titration is completed within 2 hours, then a certain time of heat preservation is carried out, and then the mixed solution of the initiator and the organic solvent is added and continues to be heat preserved; Step 4: after a certain time of heat preservation, the mixed solution of the polyethylene glycol diacrylate and the organic solvent is added and continues to be heat preserved; Step 5: the organic solvent is added, the temperature is lowered, and stirring is carried out to obtain the degradable solvent type acrylic ester pressure sensitive adhesive.

[0069] The mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; the mass of the organic solvent and initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0070] The stirring speed in the steps is 110 r / min.

[0071] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and after placing in an oven to dry the solvent, the acrylic ester pressure sensitive adhesive tape is obtained.

[0072] The thickness of the coating on the PET release film is 15 μm, the thickness of the TPU base film and the PET base film is 50 μm and 25 μm respectively, and the drying temperature and time is 120℃ and 3 min respectively.

[0073] Example 8: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, degradable crosslinking agent 0.1 part, organic solvent 60 parts, poly lactic acid (methyl) acrylic acid hydroxyethyl ester 30 parts, and poly caprolactone (methyl) acrylic acid hydroxyethyl ester 40 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0074] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the poly lactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the poly caprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g, and the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

[0075] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, hard monomer and functional monomer are mixed into a mixture, the mixture is divided into a part (70%) and a part (30%) in a certain mass ratio, the a part is added with an organic solvent and stirred in a reaction kettle, the b part is added with polylactic acid (meth) acrylic acid hydroxyethyl ester, polycaprolactone (meth) acrylic acid hydroxyethyl ester, organic solvent and initiator are stirred and placed in high level dropping tank 1; the organic solvent and initiator are stirred and placed in high level dropping tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and organic solvent in high level tank 2 are mixed and added into the reaction kettle and continue to heat, when the reaction in the reaction kettle stops heating; Step 3, after waiting for five minutes when the reaction temperature is stable, the high level dropping tank 1 starts to drop at a constant speed and is added within 2h, then a certain time is kept, and then the mixed solution of initiator and organic solvent is added to continue to keep; Step 4, after keeping for a certain time, the mixed solution of polyethylene glycol diacrylate and organic solvent is added to continue to keep; Step 5, organic solvent is added, cooled, stirred to obtain a degradable solvent type acrylate pressure sensitive adhesive.

[0076] The mass of the organic solvent added in the a part in step 1 is 40%, the mass of the organic solvent and initiator added in the b part high level tank 1 is 30% and 50%, the mass of the organic solvent and initiator added in the high level tank 2 is 10% and 15%; the mass of the organic solvent and initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0077] The stirring speed in all the steps is 110r / min.

[0078] The use method of the acrylate pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, placed in an oven to dry the solvent, then the acrylate pressure sensitive adhesive tape is obtained.

[0079] The thickness of the coating on the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the drying temperature and time is 120℃ and 3min respectively.

[0080] Comparative example 1: The acrylate pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, organic solvent 60 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, organic solvent 50 parts.

[0081] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobis isobutyronitrile, and the organic solvent is ethyl acetate.

[0082] The preparation method of the acrylic ester pressure-sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a portion a (70%) and a portion b (30%) in a certain mass ratio, the portion a is added with an organic solvent and stirred in a reaction kettle, the portion b is added with an organic solvent, stirred and mixed with an initiator and placed in a high-position dropping tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high-position dropping tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is warmed to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be warmed, and when the explosive polymerization state in the reaction kettle stops, heating is stopped; Step 3, after the reaction temperature is stable for five minutes, the high-position dropping tank 1 starts to be titrated at a uniform speed and the titration is completed within 2h, then a certain time of heat preservation is carried out, and then the mixed liquid of the initiator and the organic solvent is added to continue the heat preservation; Step 4, the organic solvent is added, cooled, and stirred to obtain a degradable solvent type acrylic ester pressure-sensitive adhesive.

[0083] In step 1, the mass of the organic solvent added in the portion a is 40%, the mass of the organic solvent and the initiator added in the portion b in the high-position tank 1 is 30% and 50%, the mass of the organic solvent and the initiator added in the high-position tank 2 is 10% and 15%; in step 3, the mass of the organic solvent and the initiator is 5% and 35% respectively, in step 4, the mass of the organic solvent is 30%, and the cooling refers to cooling to 45℃.

[0084] In the steps, the stirring speed is 110r / min.

[0085] The use method of the acrylic ester pressure-sensitive adhesive is as follows: the pressure-sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, placed in an oven to dry the solvent, and then the acrylic ester pressure-sensitive adhesive tape is obtained.

[0086] The thickness of the coating on the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the drying temperature and time is 120℃ and 3min respectively.

[0087] Comparative Example 2: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, organic solvent 60 parts, polylactic acid (methyl) acrylic acid hydroxyethyl ester 25 parts, and polycaprolactone (methyl) acrylic acid hydroxyethyl ester 30 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0088] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the polylactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the polycaprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g.

[0089] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1: the soft monomer, the hard monomer, and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with the organic solvent and stirred in a reaction kettle, the part b is added with the polylactic acid (methyl) acrylic acid hydroxyethyl ester, the polycaprolactone (methyl) acrylic acid hydroxyethyl ester, and the organic solvent, and the initiator is mixed and placed in a high-position dropping tank 1; the initiator and the organic solvent are mixed and placed in a high-position dropping tank 2; Step 2: then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be heated, and when the explosive polymerization in the reaction kettle stops, heating is stopped; Step 3: after the reaction temperature is stable for five minutes, the high-position dropping tank 1 starts to be titrated at a uniform speed and the titration is completed within 2 hours, then a certain time of heat preservation is carried out, and then the mixed solution of the initiator and the organic solvent is added to continue heat preservation; Step 4: the organic solvent is added, the temperature is lowered, and stirring is carried out to obtain the degradable solvent type acrylic ester pressure sensitive adhesive.

[0090] In the step 1, the mass of the organic solvent added in the part a is 40%, the masses of the organic solvent and the initiator added in the high-position tank 1 in the part b are 30% and 50% respectively, the masses of the organic solvent and the initiator added in the high-position tank 2 are 10% and 15% respectively; in the step 3, the masses of the organic solvent and the initiator are 5% and 35% respectively, in the step 4, the mass of the organic solvent is 30%, and the temperature lowering refers to lowering the temperature to 45℃.

[0091] In the steps, the stirring speed is 110 r / min.

[0092] The method for using the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and then placed in an oven to dry the solvent, thus obtaining the acrylic ester pressure sensitive adhesive tape.

[0093] The thickness of the coating on the PET release film is 15 μm, and the thickness of the TPU base film and the PET base film is 50 μm and 25 μm respectively, and the drying temperature and time are 120 °C and 3 min respectively.

[0094] Comparative Example 3: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: 100 parts of pressure sensitive adhesive base, 60 parts of organic solvent, 30 parts of polylactic acid (meth) acrylic acid hydroxyethyl ester, and 30 parts of polycaprolactone (meth) acrylic acid hydroxyethyl ester. The pressure sensitive adhesive base comprises the following raw materials by weight: 70 parts of soft monomer, 20 parts of hard monomer, 8 parts of functional monomer, 0.3 parts of initiator, and 50 parts of organic solvent.

[0095] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the polylactic acid (meth) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the polycaprolactone (meth) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g.

[0096] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1: the soft monomer, the hard monomer, and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with polylactic acid (meth) acrylic acid hydroxyethyl ester, polycaprolactone (meth) acrylic acid hydroxyethyl ester, and an organic solvent, and the mixture is stirred and placed in a high-position dropping tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high-position dropping tank 2; Step 2: then nitrogen is introduced, when the reaction kettle is heated to 65 °C, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to be heated, and when the reaction in the reaction kettle stops, heating is stopped; Step 3: after waiting for five minutes for the reaction temperature to be stable, the high-position dropping tank 1 starts to be titrated at a constant speed and the titration is completed within 2 h, then a certain time of heat preservation is carried out, and then the mixed solution of the initiator and the organic solvent is added and continues to be heat preserved; Step 4: the organic solvent is added, the temperature is lowered, and the mixture is stirred to obtain a degradable solvent type acrylic ester pressure sensitive adhesive.

[0097] The mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; the mass of the organic solvent and initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃.

[0098] The stirring speed in the steps is 110 r / min.

[0099] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and then placed in an oven to dry the solvent, and then the acrylic ester pressure sensitive adhesive tape is obtained.

[0100] The thickness of the coating on the PET release film is 15 μm, the thickness of the TPU base film and the PET base film is 50 μm and 25 μm respectively, and the drying temperature and time is 120℃ and 3 min respectively.

[0101] Comparative Example 4: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, organic solvent 60 parts, polylactic acid (methyl) acrylic acid hydroxyethyl ester 20 parts, and polycaprolactone (methyl) acrylic acid hydroxyethyl ester 40 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0102] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the polylactic acid (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the polycaprolactone (methyl) acrylic acid hydroxyethyl ester is 200-300, and the hydroxyl value is 300-400 KOH mg / g.

[0103] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part a (70%) and a part b (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with polylactic acid (methyl) acrylic acid hydroxyethyl ester, polycaprolactone (methyl) acrylic acid hydroxyethyl ester, an organic solvent, and an initiator, and stirred and mixed and placed in a high dropping tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high dropping tank 2; Step 2, then nitrogen is introduced, when the reactor is heated to 65℃, the initiator and organic solvent in high tank 2 are mixed and added into the reactor and continue to heat, until the reactor is in the state of explosive polymerization, stop heating; Step 3, after waiting for five minutes, the high-speed dropping tank 1 starts to drop at a constant speed and is completed within 2h, then heat for a certain time, and then add the mixture of initiator and organic solvent and continue to heat; Step 4, add organic solvent, cool, stir to obtain a degradable solvent type acrylic ester pressure sensitive adhesive.

[0104] In step 1, the mass of the organic solvent added in part a is 40%, the mass of the organic solvent and initiator added in high tank 1 in part b is 30% and 50%, the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; in step 3, the mass of the organic solvent and initiator is 5% and 35%, respectively, in step 4, the mass of the organic solvent is 30%, and the cooling refers to cooling to 45℃.

[0105] The stirring speed in all steps is 110r / min.

[0106] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film, dried, then transferred to a TPU base film or directly coated on a PET base film, placed in an oven to dry the solvent, and then an acrylic ester pressure sensitive adhesive tape is obtained.

[0107] The thickness of the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm, respectively, and the drying temperature and time is 120℃ and 3min, respectively.

[0108] Comparative Example 5: The acrylic ester pressure sensitive adhesive comprises the following raw materials by weight: pressure sensitive adhesive base 100 parts, organic solvent 60 parts, polylactic acid (methyl) hydroxyethyl acrylate 30 parts, and polycaprolactone (methyl) hydroxyethyl acrylate 20 parts. The pressure sensitive adhesive base comprises the following raw materials by weight: soft monomer 70 parts, hard monomer 20 parts, functional monomer 8 parts, initiator 0.3 parts, and organic solvent 50 parts.

[0109] The soft monomer is isooctyl acrylate, the hard monomer is methyl acrylate, the functional monomer is hydroxyethyl acrylate, the initiator is azobisisobutyronitrile, and the organic solvent is ethyl acetate. The number average molecular weight of the polylactic acid (methyl) hydroxyethyl acrylate is 200-300, and the hydroxyl value is 100-200 KOH mg / g; the weight average molecular weight of the polycaprolactone (methyl) hydroxyethyl acrylate is 200-300, and the hydroxyl value is 300-400 KOH mg / g.

[0110] The preparation method of the acrylic ester pressure sensitive adhesive comprises the following steps: Step 1, the soft monomer, the hard monomer and the functional monomer are mixed into a mixture, the mixture is divided into a part (70%) and a part (30%) in a certain mass ratio, the part a is added with an organic solvent and stirred in a reaction kettle, the part b is added with polylactic acid (meth) acrylic acid hydroxyethyl ester, polycaprolactone (meth) acrylic acid hydroxyethyl ester, an organic solvent and an initiator are stirred and mixed and placed in a high-position dropping tank 1; the organic solvent and the initiator are stirred and mixed and placed in a high-position dropping tank 2; Step 2, then nitrogen is introduced, when the reaction kettle is heated to 65℃, the initiator and the organic solvent in the high-position tank 2 are mixed and added into the reaction kettle and continue to heat, when the reaction in the reaction kettle stops, heating is stopped; Step 3, after waiting for five minutes when the reaction temperature is stable, the high-position dropping tank 1 starts to drop at a uniform speed and is added within 2h, then a certain time is kept, and then the mixed liquid of the initiator and the organic solvent is added to continue to keep; Step 4, the organic solvent is added, the temperature is lowered, and the mixture is stirred to obtain a degradable solvent type acrylic ester pressure sensitive adhesive.

[0111] The mass of the organic solvent added in the part a in step 1 is 40%, the mass of the organic solvent and the initiator added in the high-position tank 1 in the part b is 30% and 50%, the mass of the organic solvent and the initiator added in the high-position tank 2 is 10% and 15%; the mass of the organic solvent and the initiator in step 3 is 5% and 35% respectively, the mass of the organic solvent in step 4 is 30%, and the temperature is lowered to 45℃.

[0112] The stirring speed in all the steps is 110r / min.

[0113] The use method of the acrylic ester pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and then placed in an oven to dry the solvent, and then the acrylic ester pressure sensitive adhesive tape is obtained.

[0114] The thickness of the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the temperature and time of drying are 120℃ and 3min respectively.

[0115] Performance test: The pressure sensitive adhesive prepared in examples 1-8 and comparative examples 1-5 is used as a sample and the following tests are carried out respectively. Viscosity test: according to GB / T2794-1995 standard, the sample is measured by a digital viscometer at 25℃.

[0116] Solid content test: The solid content of the adhesive, also known as the non-volatile content, is the mass percentage of non-volatile substances in the adhesive under specified test conditions. The theoretical solid contents of Examples 1-3 and Comparative Examples 1-3 in the present application are all adjusted to 35.5%. First, the mass of the clean and dry watch glass is measured as m0, then a certain amount of pressure-sensitive adhesive is added to the watch glass with a mass of m1 after peeling, and it is placed in a programmable high-temperature oven at 150°C for drying for 25 min (with air blowing), and the mass is recorded as m2. The same sample is tested and calculated according to the above operation steps for 3 times, and the average value is taken.

[0117] Solid content: G = (m2-m0) / m1; Wherein, G is the solid content (%); m0 is the mass of the watch glass (g); m1 is the mass of the sample after peeling but before drying (g); m2 is the mass of the watch glass and the sample after drying (g).

[0118] 180° peeling strength test: According to GB / T2792-2014 standard, tensile test is used for testing.

[0119] Initial adhesion test: According to GB / T4852-2002 standard, a steel ball is used to test the sample, and the larger the steel strength, the better the initial adhesion.

[0120] Holding adhesion test: According to GB / T4851-2014 standard, the test sample is prepared, and the holding time of each sample is recorded.

[0121] Low temperature resistance test: The samples for 180° peeling test are placed in the conditions of "-5°C, -20°C, -35°C" for 24 h, and then the 180° peeling strength of the corresponding samples is tested.

[0122] Test results: The detailed test results are shown in Table 1.

[0123] Table 1: Comparison of basic properties of Examples 1-8 and Comparative Examples 1-5, the details are as follows:

[0124] As can be seen from Table 1, Examples 3 and 7 both occur gelation phenomenon during the reaction. Compared with Comparative Examples 1-5, Examples 1 and 5 both have suitable initial adhesion, suitable peeling force on the substrate, and relatively long holding adhesion time.

[0125] As can be seen from Table 2, by adjusting the ratio of polylactic acid propylene glycol acrylate and polycaprolactone hydroxyethyl ester, the balance of the degradation rate and low temperature performance of the pressure sensitive adhesive can be easily adjusted. When faster degradation is needed, the proportion of PLA can be appropriately increased; when better low temperature resistance is needed, the proportion of PCL can be appropriately increased. At the same time, by controlling the amount of PEGDA crosslinking agent, the cohesive strength and peel strength of the pressure sensitive adhesive can be accurately controlled to meet the needs of different application scenarios from disposable convenience to high performance industrial tape.

[0126] Table 2: Comparison of low temperature resistance test data of examples 1-8 and comparative examples 1-5, details as follows:

[0127] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, and any simple modification, equivalent replacement and improvement of the above embodiments within the scope of the technical solution of the present application, in accordance with the technical essence of the present application, within the spirit and principles of the present application, are all within the protection scope of the present application.

Claims

1. A cold resistant degradable solvent borne acrylate pressure sensitive adhesive, characterized in that, The mass fraction of each component in the pressure-sensitive adhesive is: 100 parts of pressure-sensitive adhesive base, 0.1-0.8 parts of degradable crosslinking agent, 60-80 parts of organic solvent, 20-30 parts of polylactic acid hydroxyethyl acrylate, and 20-40 parts of polycaprolactone hydroxyethyl acrylate. The pressure-sensitive adhesive base comprises the following raw materials by weight: 50-70 parts of soft monomer, 20-40 parts of hard monomer, 5-8 parts of functional monomer, 0.1-0.5 parts of initiator, and 60-180 parts of organic solvent.

2. The low-temperature resistant degradable solvent-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that, The soft monomer is any one or several of ethyl acrylate, butyl acrylate, isooctyl acrylate, and lauryl methacrylate; The hard monomer is any one or several of methyl acrylate, vinyl acetate, tert-butyl acrylate, and isobornyl methacrylate. 3.The low-temperature resistant degradable solvent-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that, The functional monomer is any one or several of acrylic acid, isooctyl acrylate, hydroxybutyl acrylate, and glycidyl methacrylate. The initiator is any one or several of dibenzoyl peroxide, azobisisobutyronitrile, azobisisopentyl nitrile, and azobisisoheptyl nitrile. The organic solvent is any one or several of ethyl acetate, cyclohexane, toluene, and isopropyl alcohol. 4.The low-temperature-resistant degradable solvent-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that, The number average molecular weight of the polylactic acid hydroxyethyl acrylate is 100-500, and the hydroxyl value is 100-300 KOH mg / g; the weight average molecular weight of the polycaprolactone hydroxyethyl acrylate is 200-400, and the hydroxyl value is 200-500 KOH mg / g. The degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200. The number average molecular weight of the polylactic acid hydroxyethyl acrylate is 100-500, and the hydroxyl value is 100-300 KOH mg / g; the weight average molecular weight of the polycaprolactone hydroxyethyl acrylate is 200-400, and the hydroxyl value is 200-500 KOH mg / g; the degradable crosslinking agent is polyethylene glycol diacrylate, and the number average molecular weight is 50-200.

5. A process for the preparation of a low temperature resistant degradable solvent borne acrylate pressure sensitive adhesive, characterized in that, The specific steps include: Step 1, mix the soft monomer, hard monomer, and functional monomer into a mixture, divide the mixture into a and b parts, add organic solvent to a part and stir in a reaction kettle, add polylactic acid hydroxyethyl acrylate, polycaprolactone hydroxyethyl acrylate, and organic solvent to b part, stir and mix with the initiator, and place in high-level dropping tank 1; stir and mix the organic solvent and initiator, and place in high-level dropping tank 2; wherein a part is 50%-80%, and b part is 20%-50%; Step 2, then introduce nitrogen, when the reaction kettle is heated to 65℃, mix the initiator and organic solvent in high-level tank 2, add to the reaction kettle, and continue to heat, and stop heating when the reaction in the reaction kettle reaches the explosive polymerization state; Step 3, after waiting for five minutes for the reaction temperature to stabilize, start uniform dropping of high-level dropping tank 1 and complete dropping within 2 hours, then perform heat preservation, and then add the mixed solution of initiator and organic solvent for further heat preservation; Step 4, after heat preservation, add the mixed solution of polyethylene glycol diacrylate and organic solvent for further heat preservation; Step 5, add organic solvent, cool, stir, and obtain the degradable solvent-type acrylate pressure-sensitive adhesive. 6.The low-temperature resistant degradable acrylate pressure-sensitive adhesive according to claim 5, wherein, The mass of the organic solvent added in part a of step 1 is 40%, the mass of the organic solvent and initiator added in high tank 1 of part b is 30% and 50%, and the mass of the organic solvent and initiator added in high tank 2 is 10% and 15%; The mass of the organic solvent and initiator in step 3 is 5% and 35% respectively; The mass of the organic solvent in step 4 is 30%, and the cooling refers to cooling to 45℃. 7.The low-temperature resistant degradable acrylate pressure-sensitive adhesive according to claim 5, wherein, The stirring speed in steps 1 to 5 is 110r / min. 8.The low-temperature resistant degradable acrylate pressure-sensitive adhesive according to claim 5, wherein, The use method of the acrylic pressure sensitive adhesive is as follows: the pressure sensitive adhesive is coated on a PET release film and dried, then transferred to a TPU base film or directly coated on a PET base film, and after being placed in an oven to dry the solvent, the acrylic pressure sensitive adhesive tape is obtained. 9.The low-temperature resistant degradable acrylate pressure-sensitive adhesive according to claim 5, wherein, The thickness of the PET release film is 15μm, the thickness of the TPU base film and the PET base film is 50μm and 25μm respectively, and the drying temperature and time is 120℃ and 3min respectively.

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