Antistatic pressure-sensitive adhesive and preparation method thereof

Abstract

The invention discloses an anti-static pressure-sensitive adhesive and a preparation method thereof, belonging to the technical field of adhesive materials. The adhesive comprises the following raw materials, measured in parts by weight: 100 parts of an acrylate compound and 0.1-1 parts of an antioxidant; the acrylate compound is prepared from 60-90 parts of an acrylic acid monomer, 5-10 parts of a functional monomer, 5-30 parts of an ionic monomer, 1-5 parts of an isocyanate cross-linking agent and 0.1-1 parts of an initiator; the anti-static pressure-sensitive adhesive prepared by the invention has greater peel strength, viscosity-reducing effect and anti-static performance, the preparation method is simple, and the prepared anti-static pressure-sensitive adhesive has stable properties.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesive materials, and in particular is an anti-static pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] China is the world's largest semiconductor market, and its foundry industry is developing rapidly, with wafer production capacity already ranking first in the world. With the popularization and application of emerging technologies such as the Internet of Things, 5G, and artificial intelligence, foundry companies will face more diversified market demands.

[0003] In the semiconductor manufacturing process, the wafer processing accuracy and stability require a protective film made of pressure-sensitive adhesive to fix and protect the wafer. At the same time, it should be easy to remove after processing, leave no residue, and have anti-static properties to avoid damage to the wafer and photolithography pattern. However, most of the pressure-sensitive adhesives used for semiconductor protective films in China cannot have both peel strength, viscosity reduction effect and anti-static properties, which affects the diversified production of wafers.

[0004] Therefore, it is of great significance to prepare an anti-static pressure-sensitive adhesive with good performance. Summary of the invention

[0005] To solve the above problems, the purpose of the present invention is to provide an anti-static pressure sensitive adhesive and a preparation method thereof.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions: An anti-static pressure-sensitive adhesive is composed of the following raw materials, measured in parts by weight: 100 parts of an acrylate compound and 0.1 to 1 part of an antioxidant; The acrylate compound is prepared from 60 to 90 parts of acrylic acid monomer, 5 to 10 parts of functional monomer, 5 to 30 parts of ionic monomer, 1 to 5 parts of isocyanate crosslinking agent and 0.1 to 1 part of initiator.

[0007] The antioxidant is diphenylamine, p-phenylenediamine, dihydroquinoline, antioxidant 1010, antioxidant 1076 or butylated hydroxyanisole.

[0008] The acrylic acid monomer is one or two of acrylic acid, butyl acrylate, 2-methoxyethyl acrylate, cyclohexyl acrylate, isooctyl acrylate, methyl acrylate, n-decyl acrylate and isobornyl acrylate.

[0009] The functional monomers are one or two of acrylonitrile, glycidyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, acrylamide, 12-hydroxylauryl acrylate and diethylene glycol monovinyl ether.

[0010] The ionic monomer is one or two of 3-methyl imidazolium bisfluoromethanesulfonyl imide salt, 3-butyl imidazolium bistrifluoromethanesulfonyl imide salt, methacryloyloxyethyl trimethylammonium chloride and dimethylaminoethyl methacrylate.

[0011] The isocyanate crosslinking agent is isophorone diisocyanate, 4,4 ， - one or both of dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

[0012] The initiator is one or two of azobisisobutyronitrile, azobisisoheptanenitrile and dibenzoyl peroxide.

[0013] The acrylate compound is prepared according to the following method: In parts by weight, 60-90 parts of acrylic acid monomer and 5-10 parts of functional monomer are added to a reflux device with nitrogen protection, 150-200 parts of organic solvent are added thereto and stirred to dissolve, nitrogen is passed through for 30 minutes, and then heated to 80-85°C, 0.1-1 parts of initiator are added thereto, and after reacting for 4-8 hours, 5-30 parts of ionic monomer are added thereto, and the reaction is continued for 2-4 hours, and then 1-5 parts of isocyanate crosslinking agent are added thereto, and the reaction is carried out for 2-3 hours to obtain an acrylate compound.

[0014] The organic solvent is one or two of toluene, ethyl acetate, butyl acetate, cyclohexane and acetone.

[0015] The method for preparing the anti-static pressure-sensitive adhesive comprises the following steps: By weight, 100 parts of acrylate compound and 0.1-1 part of antioxidant are stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0016] Compared with the prior art, the present invention has the following advantages: The antistatic pressure-sensitive adhesive of the present invention introduces ionic monomers, isocyanate groups and polar groups into an acrylic ester polymer, wherein the ions block with the acrylic ester and exist stably, and the current generated in the tearing process is released through ionic conduction, so as to achieve an antistatic effect, and the obtained compound has more stable properties and can be stored for a long time; the isocyanate groups, the conductive ions and the polar groups form a fixed cross-linked network structure, so as to avoid the random migration and shedding of the conductive ions, and at the same time, the polar groups conduct charges by forming bridge bonds, so as to enhance the antistatic effect; and the isocyanate groups react with active hydrogen to form a cross-linked structure, so as to avoid the precipitation of hydrogen ions and the reaction with the contact surface of the wafer to corrode the wafer, reduce the generation of residual adhesive, and ensure the viscosity reduction effect; the introduction of polar groups such as hydroxyl groups, amide groups and amino groups can promote the interaction between molecules, improve the cohesive force of the antistatic pressure-sensitive adhesive, reduce the steric hindrance of the cross-linking reaction, reduce the surface resistance, and effectively improve the antistatic performance.

[0017] In the anti-static pressure-sensitive adhesive of the present invention, ionic monomers, isocyanate groups and polar groups are combined on an acrylate polymer in a block copolymerization manner to form a long network chain, which is helpful to improve the peeling strength; at the same time, the network structure is tightly combined with each group to avoid the influence of excessive migration and precipitation of ions on wafer performance, thereby improving the stability of the pressure-sensitive adhesive tape; by introducing an antioxidant into the acrylate compound, hydrogen protons are provided to combine with free radicals to eliminate free radicals, thereby preventing the chain reaction from proceeding, thereby avoiding excessive cohesion after the introduction of polar groups, unstable peeling effect, and residual adhesive during peeling.

[0018] The anti-static pressure-sensitive adhesive prepared by the invention has greater peeling strength, viscosity-reducing effect and anti-static performance, and the preparation method is simple; the prepared anti-static pressure-sensitive adhesive has stable properties. DETAILED DESCRIPTION

[0019] In order to better understand the technical solution of the present invention, the above content of the present invention is further described in detail below through specific implementation methods in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies realized based on the above content of the present invention belong to the scope of the present invention.

[0020] Example 1 Preparation of Acrylate Compounds: 8.3 kg of acrylic acid and 0.7 kg of acrylamide were added to a reflux device with nitrogen protection, 18 kg of ethyl acetate was added thereto and stirred to dissolve, nitrogen was passed through for 30 minutes, and the mixture was heated to 85°C. 0.04 kg of azobisisobutyronitrile was added thereto, and the reaction was continued for 5 hours. Then, 1 kg of 3-methylimidazole bisfluoromethanesulfonyl imide was added thereto, and the reaction was continued for 3 hours. Then, 0.2 kg of isophorone diisocyanate was added thereto, and the reaction was continued for 2.5 hours to obtain an acrylate compound.

[0021] Preparation of anti-static pressure-sensitive adhesive: 10 kg of acrylate compound and 0.05 kg of diphenylamine were stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0022] Example 2 Preparation of Acrylate Compounds: 7.2 kg of acrylic acid and 1 kg of acrylonitrile were added to a reflux device with nitrogen protection, 16 kg of butyl acetate was added thereto and stirred to dissolve, nitrogen was passed through for 30 min, and then heated to 80 °C, 0.05 kg of dibenzoyl peroxide was added thereto, and after reacting for 5 h, 1.5 kg of 3-methylimidazole bis(fluoromethanesulfonyl)imide salt was added thereto, and the reaction was continued for 3 h, and then 0.3 kg of 4,4 ， -dicyclohexylmethane diisocyanate, react for 2.5h to obtain an acrylate compound.

[0023] Preparation of antistatic pressure sensitive adhesive: 10 kg of acrylate compound and 0.03 kg of antioxidant 1010 were stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0024] Example 3 Preparation of Acrylate Compounds: 6 kg of methyl acrylate and 0.5 kg of 2-hydroxybutyl acrylate were added to a reflux device with nitrogen protection, 15 kg of cyclohexane was added thereto and stirred to dissolve, nitrogen was passed through for 30 min, and then heated to 80 ° C, 0.01 kg of azobisisoheptanenitrile was added thereto, and after reacting for 4 h, 0.5 kg of methacryloyloxyethyl trimethylammonium chloride was added thereto, and the reaction was continued for 2 h, and then 0.1 kg of 4,4 ， -dicyclohexylmethane diisocyanate, react for 2h to obtain an acrylate compound.

[0025] Preparation of antistatic pressure sensitive adhesive: 10 kg of acrylate compound and 0.01 kg of antioxidant 1076 were stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0026] Example 4 Preparation of Acrylate Compounds: 8.5 kg of n-decyl acrylate and 0.8 kg of diethylene glycol monovinyl ether were added to a reflux device with nitrogen protection, 19 kg of acetone was added thereto and stirred to dissolve, nitrogen was passed through for 30 minutes, and the mixture was heated to 83°C. 0.07 kg of azobisisoheptanenitrile was added thereto, and the mixture was reacted for 7 hours. Then, 2 kg of 3-butylimidazole bistrifluoromethanesulfonyl imide was added thereto, and the reaction was continued for 3.5 hours. Then, 0.3 kg of hexamethylene diisocyanate was added thereto, and the reaction was continued for 2.5 hours to obtain an acrylate compound.

[0027] Preparation of antistatic pressure sensitive adhesive: 10 kg of acrylate compound and 0.05 kg of p-phenylenediamine were stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0028] Example 5 Preparation of Acrylate Compounds: 9 kg of isobornyl acrylate and 1 kg of 12-hydroxylauryl acrylate were added to a reflux device with nitrogen protection, 20 kg of toluene was added thereto and stirred to dissolve, nitrogen was passed through for 30 minutes, and the mixture was heated to 85°C. 0.1 kg of azobisisoheptanenitrile was added thereto, and after reacting for 8 hours, 3 kg of dimethylaminoethyl methacrylate was added thereto, and the reaction was continued for 4 hours, and 0.5 kg of isophorone diisocyanate was added thereto, and the reaction was continued for 3 hours to obtain an acrylate compound.

[0029] Preparation of antistatic pressure sensitive adhesive: 10 kg of acrylate compound and 0.1 kg of butylated hydroxyanisole were stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0030] Comparative Example 1 An antistatic pressure sensitive adhesive was prepared in the same manner as in Example 1, except that isophorone diisocyanate was not added during the preparation of the acrylate compound.

[0031] Comparative Example 2 Preparation of antistatic pressure sensitive adhesive: 10 kg of acrylate compound, 0.05 kg of diphenylamine and 0.2 kg of isophorone diisocyanate were stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

[0032] The method for preparing the acrylate compound is different from that in Example 1 in that isophorone diisocyanate is not added during the preparation of the acrylate compound.

[0033] Comparative Example 3 An antistatic pressure sensitive adhesive was prepared by the same method as in Example 1, except that in the preparation of the acrylate compound, the functional monomer acrylamide was replaced by acrylic acid.

[0034] Performance Testing The antistatic pressure-sensitive adhesive prepared in Examples 1 to 5 and Comparative Examples 1 to 2 was coated on a 38 μm PET corona layer, baked in an oven at 70°C for 3 minutes, the dry adhesive layer was 15 μm thick, and covered with a 20 μm release film to obtain an antistatic protective film. The obtained antistatic protective film was subjected to a performance test, and the test method was as follows: Peel strength test method: Peel strength test was carried out according to the method of GB / T2792-2014 "Adhesive tape peel strength test method", the sample was 300mm long and 10mm wide, 180° peeling, and the peeling speed was 300mm / min.

[0035] Surface resistance test method: Surface resistivity test was conducted according to GB / T1410-2006 "Test method for volume resistivity and surface resistivity of solid insulating materials", and the surface resistivity was tested after wet heat storage: 60°C, 90%RH, 72h. The test results are shown in Table 1.

[0036] Table 1 Performance test results of antistatic protective film

[0037] It can be seen from the results in Table 1 that the pressure-sensitive adhesive prepared in Comparative Example 2 has a better viscosity-reducing effect than that in Comparative Example 1 due to the addition of isocyanate. In Comparative Example 2, since the isocyanate and the acrylate compound are stirred and mixed, the isocyanate group and the functional group are disorderly combined, so it is easy to react with the active hydrogen-containing compound to generate by-products, affecting the performance of the adhesive. Comparative Example 3 does not add functional monomers, and the conductive ions lack a bridging structure when they are transmitted in the isocyanate network structure, and the ion migration speed decreases, affecting the antistatic and viscosity-reducing effects; the antistatic pressure-sensitive adhesive prepared by the present invention blocks the isocyanate crosslinker with the polar group and the ionic monomer in the acrylate polymer to form a network structure, and the pressure-sensitive adhesive thus prepared has excellent peeling force and viscosity-reducing effect while also having antistatic properties, and the ions in the pressure-sensitive adhesive are not easy to precipitate, and there is no residual glue on the surface of the adherend during peeling, and the peeling performance is stable, so that the wafer is effectively protected.

[0038] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. An anti-static pressure-sensitive adhesive, characterized in that: The composition is composed of the following raw materials in parts by weight: 100 parts of acrylate compound and 0.1-1 parts of antioxidant; The acrylate compound is prepared from 60 to 90 parts of acrylic acid monomer, 5 to 10 parts of functional monomer, 5 to 30 parts of ionic monomer, 1 to 5 parts of isocyanate crosslinking agent and 0.1 to 1 part of initiator.

2. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The antioxidant is diphenylamine, p-phenylenediamine, dihydroquinoline, antioxidant 1010, antioxidant 1076 or butylated hydroxyanisole.

3. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The acrylic acid monomer is one or two of acrylic acid, butyl acrylate, 2-methoxyethyl acrylate, cyclohexyl acrylate, isooctyl acrylate, methyl acrylate, n-decyl acrylate and isobornyl acrylate.

4. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The functional monomers are one or two of acrylonitrile, glycidyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, acrylamide, 12-hydroxylauryl acrylate and diethylene glycol monovinyl ether.

5. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The ionic monomer is one or two of 3-methyl imidazolium bisfluoromethanesulfonyl imide salt, 3-butyl imidazolium bistrifluoromethanesulfonyl imide salt, methacryloyloxyethyl trimethylammonium chloride and dimethylaminoethyl methacrylate.

6. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The isocyanate crosslinking agent is isophorone diisocyanate, 4,4 ， - one or both of dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

7. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The initiator is one or two of azobisisobutyronitrile, azobisisoheptanenitrile and dibenzoyl peroxide.

8. The antistatic pressure sensitive adhesive according to claim 1, characterized in that: The acrylate compound is prepared according to the following method: In parts by weight, 60-90 parts of acrylic acid monomer and 5-10 parts of functional monomer are added to a reflux device with nitrogen protection, 150-200 parts of organic solvent are added thereto and stirred to dissolve, nitrogen is passed through for 30 minutes, and then heated to 80-85°C, 0.1-1 parts of initiator are added thereto, and after reacting for 4-8 hours, 5-30 parts of ionic monomer are added thereto, and the reaction is continued for 2-4 hours, and then 1-5 parts of isocyanate crosslinking agent are added thereto, and the reaction is carried out for 2-3 hours to obtain an acrylate compound.

9. The antistatic pressure sensitive adhesive according to claim 8, characterized in that: The organic solvent is one or two of toluene, ethyl acetate, butyl acetate, cyclohexane and acetone.

10. The method for preparing the antistatic pressure sensitive adhesive according to claim 1, characterized in that: The following steps are involved: By weight, 100 parts of acrylate compound and 0.1-1 part of antioxidant are stirred and mixed uniformly to obtain an antistatic pressure-sensitive adhesive.

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