Uv reduced adhesion pressure sensitive adhesive, method of making and use thereof

Abstract

The embodiment of the present disclosure provides a UV tack-reducing pressure-sensitive adhesive, a preparation method and application thereof, and belongs to the field of wafer processing. The UV tack-reducing pressure-sensitive adhesive provided by the embodiment of the present disclosure comprises the following components by weight: 8-25 parts of a bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compound, 13-35 parts of a 1,6-hexanediol diglycidyl ether acrylic ring-opening compound, 8-20 parts of a pentaerythritol acrylate, 0.1-3.5 parts of isophorone diisocyanate, 25-65 parts of an acrylate diluent, and 0.01-0.5 parts of a photoinitiator. The UV tack-reducing pressure-sensitive adhesive prepared by the embodiment of the present disclosure has strong room temperature adhesion, strong photosensitivity, fast curing speed, and greatly reduced adhesion after curing, is easy to tear off, and does not produce residual glue.

Description

Technical Field

[0001] This disclosure relates to the field of wafer processing, and in particular to a UV-resistant pressure-sensitive adhesive, its preparation method, and its application. Background Technology

[0002] In the wafer fabrication industry, UV-curing pressure-sensitive adhesives (PSAs) require high peel strength to withstand the shear forces during high-speed peeling. However, with the continuous development of electronic products, traditional UV PSAs suffer from drawbacks such as slow UV curing speed and high peel strength leading to residue buildup. Therefore, it is necessary to develop a new type of UV PSA that can meet the requirements of high-speed processing, while also offering higher curing speeds during UV curing and minimizing residue buildup, thus ensuring product quality and reliability. Summary of the Invention

[0003] This disclosure provides a UV-resistant pressure-sensitive adhesive, its preparation method, and its application. The UV-resistant pressure-sensitive adhesive, after short-term irradiation with UV light of a specific wavelength, exhibits strong adhesion at room temperature, rapid curing speed, significantly reduced adhesion after curing, easy removal, and no residue. The technical solution is as follows:

[0004] On one hand, a UV-resistant pressure-sensitive adhesive is provided, comprising the following components in parts by weight:

[0005] The mixture contains 8-25 parts of bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound, 13-35 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 8-20 parts of pentaerythritol acrylate, 0.1-3.5 parts of isophorone diisocyanate, 25-65 parts of acrylate diluent, and 0.01-0.5 parts of photoinitiator.

[0006] In one possible implementation, the bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound is a ring-opening synthesis of bisphenol A epoxy or bisphenol F epoxy resin with an epoxy equivalent ≤186 obtained by recrystallization purification and acrylic acid.

[0007] In another possible implementation, the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound is a ring-opening synthesis of 1,6-hexanediol diglycidyl ether and acrylic acid with an epoxy value of 0.65 to 0.7%.

[0008] In another possible implementation, the pentaerythritol acrylate has a specific gravity of 1.172, a refractive index of 1.4841, and an acid value of 0.17 mg KOH / g.

[0009] In another possible implementation, the isophorone diisocyanate has an isocyanate group mass fraction ≥37.5%, a color ≤30, hydrolyzed chlorine ≤200mg / kg, and total chlorine ≤400mg / kg.

[0010] In another possible implementation, the acrylate diluent includes at least one of butyl acrylate, isooctyl acrylate, isodecyl acrylate, octadecyl acrylate, and dodecyl methacrylate.

[0011] On the other hand, a method for preparing a UV-resistant pressure-sensitive adhesive is provided, the steps of which are as follows:

[0012] According to the weight parts of each component, the 1,6-hexanediol diglycidyl ether acrylate ring-opening compound and the bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound are mixed evenly to obtain material 1;

[0013] The pentaerythritol acrylate was added to material 1 and mixed evenly to obtain material 2;

[0014] The acrylate diluent is added to material 2 and mixed evenly to obtain material 3;

[0015] The isophorone diisocyanate was added dropwise to material 3 over a period of 45–75 min at a reaction temperature of 75–85 °C to obtain material 4.

[0016] The photoinitiator was added to material 4 under the light source of a light-emitting diode (LED) cadmium yellow lamp to obtain the UV-resistant pressure-sensitive adhesive.

[0017] In one possible implementation, the preparation method further includes:

[0018] Acrylic acid was added to 1,6-hexanediol diglycidyl ether, followed by the addition of a first polymerization inhibitor and a first catalyst. The reaction time was 3.5–4.5 h, and the reaction temperature was 80–120 °C, to obtain the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound.

[0019] In another possible implementation, the preparation method further includes:

[0020] Bisphenol A or bisphenol F epoxy resin was dissolved in a mixed solvent of n-heptane and ethyl acetate, and then separated by recrystallization to obtain bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182.

[0021] Acrylic acid is added to the bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182, and then a second polymerization inhibitor and a second catalyst are added. The reaction time is 5-6 hours and the reaction temperature is 75-110°C to obtain the bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compound.

[0022] On the other hand, an application of the UV-reducing pressure-sensitive adhesive described in any of the above claims in wafer processing is provided.

[0023] The UV-reducing pressure-sensitive adhesive provided in this embodiment introduces a rigid benzene ring structure into the bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound, and the 1,6-hexanediol diglycidyl ether acrylate ring-opening compound has a flexible aliphatic long-chain structure. The diisocyanate in isophorone diisocyanate has a six-membered ring structure. Its isocyanate group reacts with the rigid benzene ring structure, the flexible aliphatic long-chain structure, the hydroxyl group in pentaerythritol acrylate, and the hydroxyl group in acrylate diluent to generate a UV-reducing pressure-sensitive adhesive with a complex cross-linked system of interpenetrating network, which ensures both the rigidity and high toughness of the UV-reducing pressure-sensitive adhesive. Furthermore, bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compounds are characterized by a high content of carbon-carbon double bonds (C=C). The addition of high-density multi-functional pentaerythritol acrylate and acrylate diluents further increases the content of carbon-carbon double bonds. Therefore, the UV-resistant pressure-sensitive adhesive prepared by the crosslinking action of isophorone diisocyanate under the above high-density multi-functional groups also has the characteristics of high active group density and strong reactivity. It cures rapidly after UV light irradiation, the adhesion force decreases rapidly, and no residue is produced. It can be seen that this UV-resistant pressure-sensitive adhesive has high peel strength, fast curing speed after UV light irradiation, significant reduction in adhesion force, and is easy to remove without leaving residue. Detailed Implementation

[0024] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this disclosure.

[0025] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of this disclosure belong. The terminology used in this specification of embodiments is for the purpose of describing particular implementations only and is not intended to limit the scope of embodiments of this disclosure. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0026] This disclosure provides a UV-resistant pressure-sensitive adhesive, comprising the following components in parts by weight:

[0027] The mixture contains 8-25 parts of bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound, 13-35 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 8-20 parts of pentaerythritol acrylate, 0.1-3.5 parts of isophorone diisocyanate (IPDI), 25-65 parts of acrylate diluent, and 0.01-0.5 parts of photoinitiator.

[0028] The weight parts of the bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound can be 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, or 25 parts; the weight parts of the 1,6-hexanediol diglycidyl ether acrylate ring-opening compound can be 13 parts, 15 parts, 18 parts, 20 parts, 23 parts, 25 parts, 28 parts, 30 parts, 33 parts, or 35 parts; and the weight parts of the pentaerythritol acrylate can be 8 parts, 9 parts, 10 parts, 12 parts, 15 parts, 17 parts, 18 parts, 19 parts, or 20 parts. The weight parts of isophorone diisocyanate can be 0.1 parts, 0.3 parts, 0.5 parts, 0.8 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, and 3.5 parts; the weight parts of acrylate diluent can be 25 parts, 28 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, and 65 parts; and the weight parts of photoinitiator can be 0.01 parts, 0.03 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, and 0.5 parts.

[0029] In the embodiments of this disclosure, the bisphenol A or bisphenol F epoxy acrylate ring-opening compound is prepared by reacting bisphenol A epoxy resin or bisphenol F epoxy resin with acrylic acid. Specifically, the bisphenol A or bisphenol F epoxy acrylate ring-opening compound can be a ring-opening synthesis of bisphenol A epoxy or bisphenol F epoxy resin with an epoxy equivalent ≤186 obtained by recrystallization and purification with acrylic acid.

[0030] Specifically, bisphenol A or bisphenol F epoxy acrylate ring-opening compounds can be prepared by reacting bisphenol A epoxy resin with acrylic acid. Further, bisphenol A or bisphenol F epoxy acrylate ring-opening compounds can be prepared by reacting bisphenol A epoxy resin with an epoxy equivalent (EEW) of 176–182 g / eq with acrylic acid. Under these conditions, the bisphenol A epoxy acrylate produced by reacting bisphenol A with acrylic acid at a lower epoxy equivalent has a high acrylic acid content, exhibits high reactivity during UV curing, and the introduction of the rigid benzene ring structure of bisphenol A gives the UV-resistant pressure-sensitive adhesive high chemical and physical stability. Furthermore, its high rigidity and low shrinkage during curing, combined with the low shrinkage during high-speed dicing, allow for better protection of the wafer from damage.

[0031] In this embodiment, the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound is synthesized by ring-opening 1,6-hexanediol diglycidyl ether with low epoxy equivalent and acrylic acid. Specifically, the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound can be a ring-opening synthesis of 1,6-hexanediol diglycidyl ether with an epoxy value of 0.65% to 0.7% and acrylic acid. More specifically, the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound is a ring-opening synthesis of 1,6-hexanediol diglycidyl ether with an epoxy value of 0.67% to 0.69% and acrylic acid. Under this scheme, the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound has a compliant aliphatic long chain. The flexible long chain structure has good ductility, elongation at break, and elasticity, giving the UV pressure-sensitive adhesive excellent adhesion and toughness.

[0032] In this embodiment, pentaerythritol acrylate is a multifunctional polyester. Specifically, pentaerythritol acrylate (PET4A) can be EM241 produced by Changxing Special Materials (Zhuhai) Co., Ltd., which has a specific gravity of 1.172, a refractive index of 1.4841, and an acid value of 0.17 mgKOH / g. Under this configuration, pentaerythritol acrylate exhibits high crosslinking density, rapid curing, and good flexibility. Furthermore, each molecule contains multiple active groups that can participate in the photocuring reaction, resulting in not only a fast photocuring rate and high crosslinking density, but also, due to its large molecular weight, low volatility and high viscosity.

[0033] In this embodiment, the isocyanate group mass fraction of isophorone diisocyanate is ≥37.5%, the color (Hazen) is ≤30, the hydrolyzed chlorine is ≤200mg / kg, and the total chlorine is ≤400mg / kg. Under this scheme, its isocyanate group reacts with the hydroxyl groups in bisphenol A or bisphenol F epoxy acrylate ring-opening compound, 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, pentaerythritol acrylate, and acrylate diluent to generate a high-strength UV-resistant pressure-sensitive adhesive with a highly crosslinked system. This UV-resistant pressure-sensitive adhesive not only has rigid benzene ring groups but also has toughening groups of 1,6-hexanediol diglycidyl ether, and at the same time has high-density active groups of polyfunctional polyester in pentaerythritol acrylate, giving the UV-resistant pressure-sensitive adhesive the advantages of high strength and strong photoreactivity.

[0034] In this embodiment of the disclosure, the acrylate diluent includes at least one selected from butyl acrylate, isooctyl acrylate, isodecyl acrylate, octadecyl acrylate, and dodecyl methacrylate. The acrylate diluent may be isooctyl acrylate.

[0035] Specifically, isooctyl acrylate is a product manufactured by Shandong Hongrun Chemical Co., Ltd., with a molecular weight of 184.28 and a density of 0.88 g / cm³.3 The refractive index is 1.437. Under this scheme, isooctyl acrylate makes the UV pressure-sensitive adhesive easier to coat and provides higher transparency. Acrylic diluents are compatible with bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compounds. Acrylic diluents can also provide a certain degree of curing crosslinking, promoting the crosslinking polymerization of acrylate groups in the UV pressure-sensitive adhesive, thereby increasing the hardness, toughness, and abrasion resistance of the UV pressure-sensitive adhesive.

[0036] In this embodiment, the initiator is a photoinitiator, which can be 1-hydroxy-cyclohexyl-phenyl ketone (UV184). The photoinitiator can be a product manufactured by Koster Chemical, with a molecular weight of 204.26, a melting point of 44–48°C, volatile matter of ≤0.2%, and an absorption wavelength of 246–350 nm. In this embodiment, UV184 is a highly efficient, non-yellowing free radical (I) type solid photoinitiator with advantages of environmental friendliness and rapid curing. In this embodiment, it is used as a UV curing initiator for polyfunctional unsaturated prepolymer acrylate diluents.

[0037] This disclosure provides a method for preparing a UV-resistant pressure-sensitive adhesive, comprising the following steps:

[0038] Step 1: According to the weight parts of each component, mix the 1,6-hexanediol diglycidyl ether acrylic ring-opening compound and the bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compound evenly to obtain material 1.

[0039] In step one, the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound, bisphenol A epoxy or bisphenol F epoxy acrylic acid ring-opening compound can be mixed evenly by stirring for 20 to 50 minutes, at a temperature of 25 to 30°C, and at a stirring speed of 100 to 200 rpm.

[0040] The stirring time can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, or 50 min; the stirring temperature can be 25℃, 26℃, 27℃, 28℃, 29℃, or 30℃; and the stirring speed can be 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 180 rpm, or 200 rpm.

[0041] It should be noted that before step one, a ring-opening compound of 1,6-hexanediol diglycidyl ether acrylate and a ring-opening compound of bisphenol A epoxy or bisphenol F epoxy acrylate are prepared first.

[0042] The preparation process of the ring-opening compound of 1,6-hexanediol diglycidyl ether acrylic acid is as follows:

[0043] Acrylic acid was added to 1,6-hexanediol diglycidyl ether at a first preset ratio, followed by the addition of a first polymerization inhibitor and a first catalyst. The reaction time was 3.5–4.5 h, and the reaction temperature was 80–120 °C, to obtain the ring-opening compound of 1,6-hexanediol diglycidyl ether acrylic acid with a yield of 87.35%.

[0044] The mass ratio of acrylic acid to 1,6-hexanediol diglycidyl ether is 2.2:1, the mass fraction of the first polymerization inhibitor is 0.6%, and the mass fraction of the first catalyst is 0.5%. The mass fraction of the first polymerization inhibitor is the ratio of its mass to the total mass of acrylic acid and 1,6-hexanediol diglycidyl ether, and the mass fraction of the first catalyst is the ratio of its mass to the total mass of acrylic acid and 1,6-hexanediol diglycidyl ether.

[0045] The types of the first polymerization inhibitor and the first catalyst can be set and changed as needed, and there is no specific limitation on them. For example, the first polymerization inhibitor is p-methoxyphenol, and the first catalyst is triethylamine.

[0046] The reaction time can be 3.5h, 3.8h, 4h, 4.2h, or 4.5h, and the reaction temperature can be 80℃, 90℃, 100℃, 110℃, or 120℃.

[0047] The preparation process of bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compounds is as follows:

[0048] Bisphenol A or bisphenol F epoxy resin was dissolved in a mixed solvent of n-heptane and ethyl acetate, and then separated by recrystallization to obtain bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182, with a yield of 10.2%.

[0049] Acrylic acid was added to bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182, followed by the addition of a second polymerization inhibitor and a second catalyst. The reaction time was 5-6 hours and the reaction temperature was 75-110°C to obtain bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compounds with a yield of 89.65%.

[0050] The mass ratio of n-heptane to ethyl acetate is 6:1, the mass ratio of acrylic acid to bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182 is 2.2:1, the mass fraction of the second polymerization inhibitor is 0.55%, and the mass fraction of the second catalyst is 0.3%.

[0051] The second polymerization inhibitor may be the same as or different from the first polymerization inhibitor, and the second catalyst may be the same as or different from the first catalyst; no specific limitations are made in this regard. In the embodiments of this disclosure, only the example of the second polymerization inhibitor being the same as the first polymerization inhibitor, the second catalyst being the same as the first catalyst, and the first polymerization inhibitor being p-methoxyphenol and the first catalyst being triethylamine, will be used for illustration.

[0052] The reaction time can be 5h, 5.2h, 5.5h, 5.8h, or 6h, and the reaction temperature can be 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, or 110℃.

[0053] Step 2: Add pentaerythritol acrylate to material 1 and mix thoroughly to obtain material 2.

[0054] In step two, pentaerythritol acrylate and material 1 can be mixed evenly by stirring. The stirring time is 20-50 minutes, the stirring temperature is 25-30℃, and the stirring speed is 100-200 rpm.

[0055] The stirring time, stirring temperature, and stirring speed in step two may be the same as or different from those in step one; no specific restrictions are imposed on these parameters.

[0056] Step 3: Add the acrylate diluent to material 2 and mix well to obtain material 3.

[0057] In step three, the acrylate diluent and material 2 can be mixed evenly by stirring. The stirring time is 20-50 minutes, the stirring temperature is 25-30℃, and the stirring speed is 100-200 rpm.

[0058] The stirring time, stirring temperature, and stirring speed in step three may be the same as or different from those in step one; no specific restrictions are imposed on these parameters.

[0059] Step 4: Add isophorone diisocyanate dropwise to material 3 over a period of 45–75 min at a reaction temperature of 75–85 °C to obtain material 4.

[0060] In step four, isophorone diisocyanate is slowly added dropwise to material 3 and stirred until homogeneous at a stirring speed of 100-200 rpm.

[0061] The dropping time can be 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, or 75 min, and the reaction temperature can be 75℃, 78℃, 80℃, 82℃, or 85℃.

[0062] Step 5: Add the photoinitiator to material 4 under the light source of a light-emitting diode (LED) cadmium yellow lamp tube to obtain a UV-resistant pressure-sensitive adhesive.

[0063] In step five, the photoinitiator is added to material 4 under the light source of a light-emitting diode (LED) cadmium yellow lamp tube, and the mixture is stirred and mixed evenly to obtain a UV-resistant pressure-sensitive adhesive.

[0064] The stirring time is 20–50 min, the stirring temperature is 25–30℃, and the stirring speed is 100–200 rpm. The stirring time, stirring temperature, and stirring speed in step five may be the same as or different from those in step one, and no specific limitations are imposed on them.

[0065] This disclosure also provides an application of UV-resistant pressure-sensitive adhesive in wafer fabrication.

[0066] In summary, the embodiments disclosed herein have the following beneficial effects:

[0067] 1. The rigid benzene ring structure in bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compounds and the flexible aliphatic long chain structure in 1,6-hexanediol diglycidyl ether acrylic ring-opening compounds, under the crosslinking action of isophorone diisocyanate with a six-membered ring structure, generate a high-strength UV-resistant pressure-sensitive adhesive with a complex crosslinking system of interpenetrating network. This ensures both the rigidity and high toughness of the UV-resistant pressure-sensitive adhesive, giving it high adhesion and strong tack at room temperature.

[0068] 2. Epoxy resins with specific epoxy equivalents are screened and reacted with acrylic acid to generate epoxy acrylic ring-opening compounds. These compounds have a high content of carbon-carbon double bonds (C=C). The addition of high-density multi-functional pentaerythritol acrylate and acrylate diluents further increases the content of carbon-carbon double bonds. Under the network crosslinking effect of isophorone diisocyanate, the UV-resistant pressure-sensitive adhesive prepared by the above high-density multi-functional groups has the characteristics of high density of active groups and strong reactivity. It cures rapidly after UV light irradiation, the adhesion force decreases rapidly and no residue is produced.

[0069] 3. The UV-reducing pressure-sensitive adhesive provided in this embodiment also has the characteristics of strong photosensitivity, low UV curing energy required, energy saving, and high production efficiency.

[0070] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0071] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. In the following examples and comparative examples, the amounts of each UV-resistant pressure-sensitive adhesive formulation are by weight.

[0072] In the following examples, the bisphenol A or bisphenol F epoxy acrylate ring-opening compound is a bisphenol A epoxy acrylate ring-opening compound. The bisphenol A epoxy acrylate ring-opening compound is prepared by reacting bisphenol A epoxy resin with an epoxy equivalent of 176-182 with acrylic acid. The bisphenol A epoxy resin with an epoxy equivalent of 176-182 is prepared by dissolving bisphenol A epoxy resin in a solvent with a ratio of n-heptane to ethyl acetate of 6:1, followed by recrystallization and separation.

[0073] The ring-opening compound of 1,6-hexanediol diglycidyl ether acrylic acid is prepared by reacting 1,6-hexanediol diglycidyl ether with acrylic acid at an epoxy value of 0.67% to 0.69%.

[0074] The pentaerythritol acrylate was produced by Changxing Special Materials (Zhuhai) Co., Ltd.: EM241 has a specific gravity of 1.172, a refractive index of 1.4841, and an acid value of 0.17 mg KOH / g;

[0075] Isooctyl acrylate was produced by Shandong Hongrun Chemical Co., Ltd.: molecular weight 184.28, density 0.88 g / cm³. 3 Its refractive index is 1.437;

[0076] The isophorone diisocyanate is Desmodur isophorone diisocyanate produced by Bayer, Germany, with an isocyanate group mass fraction ≥37.5%, color (Hazen) ≤30, hydrolyzed chlorine ≤200mg / kg, and total chlorine ≤400mg / kg;

[0077] 1-Hydroxycyclohexylphenyl ketone is produced by Koster Chemical: molecular weight is 204.26, melting point is 44-48℃, volatile matter is ≤0.2%, and absorption wavelength is 246-350nm.

[0078] The preparation process of the 1,6-hexanediol diglycidyl ether ring-opening compound of acrylic acid is as follows:

[0079] Acrylic acid was added to 1,6-hexanediol diglycidyl ether in a ratio of 2.2:1, followed by the addition of 0.6% polymerization inhibitor p-methoxyphenol and 0.5% catalyst triethylamine. The reaction time was 6 hours, and the reaction temperature was 95°C. Under these conditions, the ring-opening compound of 1,6-hexanediol diglycidyl ether with acrylic acid was obtained in a yield of 87.35%.

[0080] The preparation process of the bisphenol A epoxy acrylate ring-opening compound is as follows;

[0081] Bisphenol A epoxy resin was dissolved in a solvent with a ratio of n-heptane to ethyl acetate of 6:1, and after recrystallization and separation, bisphenol A epoxy resin with an epoxy equivalent of 176-182 was obtained with a yield of 10.2%.

[0082] Acrylic acid was added to bisphenol A with an epoxy equivalent of 176–182 at a ratio of 2.2:1, followed by the addition of 0.55% p-methoxyphenol as a polymerization inhibitor and 0.3% triethylamine as a catalyst. The reaction was carried out for 6 hours at a temperature of 85°C. Under these conditions, a bisphenol A epoxy acrylic acid ring-opening compound was obtained with a yield of 89.65%.

[0083] The 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound and the bisphenol A epoxy acrylic acid ring-opening compound used in Examples 1-5 below were all prepared by the above method.

[0084] Example 1

[0085] This embodiment provides a UV-resistant pressure-sensitive adhesive, which is prepared from the following components in parts by weight: 17 parts of bisphenol A epoxy acrylate ring-opening compound, 26 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 18 parts of pentaerythritol acrylate, 0.4 parts of isophorone diisocyanate, 48 parts of isooctyl acrylate, and 0.05 parts of 1-hydroxycyclohexylphenyl ketone.

[0086] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0087] Step 1: Mix 26 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 17 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0088] In step one, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0089] Step 2: Add 18 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0090] The stirring time, stirring temperature, and stirring rate in step two are the same as in step one.

[0091] Step 3: Add 48 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0092] The stirring time, stirring temperature, and stirring rate in step three are the same as in step one.

[0093] Step 4: Slowly add 0.4 parts of isophorone diisocyanate to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0094] In step four, the stirring speed is 150 rpm.

[0095] Step 5: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 in the LED cadmium yellow lamp light source production environment to obtain UV anti-tack pressure-sensitive adhesive.

[0096] The stirring time, stirring temperature, and stirring rate in step five are the same as in step one.

[0097] Example 2

[0098] This embodiment provides a UV-resistant pressure-sensitive adhesive, which is prepared from the following components in parts by weight: 25 parts of bisphenol A epoxy acrylate ring-opening compound, 15 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 18 parts of pentaerythritol acrylate, 0.4 parts of isophorone diisocyanate, 48 parts of isooctyl acrylate, and 0.05 parts of 1-hydroxycyclohexylphenyl ketone.

[0099] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0100] Step 1: Mix 15 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 25 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0101] In step one, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0102] Step 2: Add 18 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0103] The stirring time, stirring temperature, and stirring rate in step two are the same as in step one.

[0104] Step 3: Add 48 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0105] The stirring time, stirring temperature, and stirring rate in step three are the same as in step one.

[0106] Step 4: Slowly add 0.4 parts of isophorone diisocyanate to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0107] In step four, the stirring speed is 150 rpm.

[0108] Step 5: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 in the LED cadmium yellow lamp light source production environment to obtain UV anti-tack pressure-sensitive adhesive.

[0109] The stirring time, stirring temperature, and stirring rate in step five are the same as in step one.

[0110] Example 3

[0111] This embodiment provides a UV-resistant pressure-sensitive adhesive, which is prepared from the following components in parts by weight: 10 parts of bisphenol A epoxy acrylate ring-opening compound, 35 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 18 parts of pentaerythritol acrylate, 0.4 parts of isophorone diisocyanate, 60 parts of isooctyl acrylate, and 0.05 parts of 1-hydroxycyclohexylphenyl ketone.

[0112] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0113] Step 1: Mix 35 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 10 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0114] In step one, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0115] Step 2: Add 18 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0116] The stirring time, stirring temperature, and stirring rate in step two are the same as in step one.

[0117] Step 3: Add 60 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0118] The stirring time, stirring temperature, and stirring rate in step three are the same as in step one.

[0119] Step 4: Slowly add 0.4 parts of isophorone diisocyanate to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0120] In step four, the stirring speed is 150 rpm.

[0121] Step 5: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 in the LED cadmium yellow lamp light source production environment to obtain UV anti-tack pressure-sensitive adhesive.

[0122] The stirring time, stirring temperature, and stirring rate in step five are the same as in step one.

[0123] Example 4

[0124] This embodiment provides a UV-resistant pressure-sensitive adhesive, which is prepared from the following components in parts by weight: 20 parts of bisphenol A epoxy acrylate ring-opening compound, 35 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 15 parts of pentaerythritol acrylate, 0.4 parts of isophorone diisocyanate, 45 parts of isooctyl acrylate, and 0.04 parts of 1-hydroxycyclohexylphenyl ketone.

[0125] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0126] Step 1: Mix 35 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 20 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0127] In step one, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0128] Step 2: Add 15 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0129] The stirring time, stirring temperature, and stirring rate in step two are the same as in step one.

[0130] Step 3: Add 45 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0131] The stirring time, stirring temperature, and stirring rate in step three are the same as in step one.

[0132] Step 4: Slowly add 0.4 parts of isophorone diisocyanate to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0133] In step four, the stirring speed is 150 rpm.

[0134] Step 5: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 in the LED cadmium yellow lamp light source production environment to obtain UV anti-tack pressure-sensitive adhesive.

[0135] The stirring time, stirring temperature, and stirring rate in step five are the same as in step one.

[0136] Example 5

[0137] This embodiment provides a UV-resistant pressure-sensitive adhesive, which is prepared from the following components in parts by weight: 8 parts of bisphenol A epoxy acrylate ring-opening compound, 35 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 18 parts of pentaerythritol acrylate, 0.4 parts of isophorone diisocyanate, 48 parts of isooctyl acrylate, and 0.05 parts of 1-hydroxycyclohexylphenyl ketone.

[0138] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0139] Step 1: Mix 35 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 8 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0140] In step one, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0141] Step 2: Add 8 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0142] The stirring time, stirring temperature, and stirring rate in step two are the same as in step one.

[0143] Step 3: Add 48 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0144] The stirring time, stirring temperature, and stirring rate in step three are the same as in step one.

[0145] Step 4: Slowly add 0.4 parts of isophorone diisocyanate to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0146] In step four, the stirring speed is 150 rpm.

[0147] Step 5: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 under the LED cadmium yellow lamp light source production environment and stir evenly to obtain UV anti-tack pressure sensitive adhesive.

[0148] The stirring time, stirring temperature, and stirring rate in step five are the same as in step one.

[0149] Comparative Example 1

[0150] This comparative example provides a UV-resistant pressure-sensitive adhesive, prepared from the following components in parts by weight: 17 parts of bisphenol A epoxy acrylate ring-opening compound, 26 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 18 parts of pentaerythritol acrylate, 0.4 parts of isophorone diisocyanate, 48 parts of isooctyl acrylate, and 0.05 parts of 1-hydroxycyclohexylphenyl ketone.

[0151] The bisphenol A epoxy acrylate ring-opening compound was prepared by reacting Dow bisphenol A liquid epoxy resin DER331 with acrylic acid. The epoxy equivalent (g / eq.) of the bisphenol A epoxy resin was 186-190, and the viscosity was 11000-14000 mPa·s at 25℃. The 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, pentaerythritol acrylate, isophorone diisocyanate, isooctyl acrylate, and 1-hydroxycyclohexylphenyl ketone were the same as those in Example 1.

[0152] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0153] Step 1: Acrylic acid was added to bisphenol A epoxy resin DER331 in a 2:1 ratio, followed by 0.55% polymerization inhibitor p-methoxyphenol and 0.3% catalyst triethylamine. The reaction time was 6 hours, and the reaction temperature was 85°C. Under these conditions, a bisphenol A epoxy acrylic acid ring-opening compound was obtained with a yield of 85.35%.

[0154] Step 2: Mix 26 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 17 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0155] In step two, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0156] Step 3: Add 18 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0157] The stirring time, stirring temperature, and stirring rate in step three are the same as in step two.

[0158] Step 4: Add 48 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0159] The stirring time, stirring temperature, and stirring rate in step four are the same as in step two.

[0160] Step 5: Slowly add 0.4 parts of isophorone diisocyanate to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0161] In step five, the stirring speed is 150 rpm.

[0162] Step 6: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 in the LED cadmium yellow lamp light source production environment to obtain UV anti-tack pressure-sensitive adhesive.

[0163] The stirring time, stirring temperature, and stirring rate in step six are the same as in step two.

[0164] Comparative Example 2

[0165] This comparative example provides a UV-resistant pressure-sensitive adhesive, prepared from the following components in parts by weight: 17 parts of bisphenol A epoxy acrylate ring-opening compound, 26 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 18 parts of pentaerythritol acrylate, 0.4 parts of MDI, 48 parts of isooctyl acrylate, and 0.05 parts of 1-hydroxycyclohexylphenyl ketone.

[0166] The MDI used was MDI-50 from Wanhua Chemical Group Co., Ltd., with a purity ≥99.6%, color number (Pt-Co) ≤30, hydrolyzed chlorine mass fraction (%) ≤0.005, and cyclohexane insoluble matter (%) ≤0.2. The bisphenol A epoxy acrylate ring-opening compound, 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, pentaerythritol acrylate, isooctyl acrylate, and 1-hydroxycyclohexylphenyl ketone were the same as in Example 1.

[0167] The preparation method of this UV-resistant pressure-sensitive adhesive is as follows:

[0168] Step 1: Mix 26 parts of 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound with 17 parts of bisphenol A epoxy acrylic acid ring-opening compound, stir evenly, and obtain material 1.

[0169] In step one, the stirring time is 30 minutes, the stirring temperature is 28°C, and the stirring speed is 150 rpm.

[0170] Step 2: Add 18 parts of pentaerythritol acrylate to material 1 and stir evenly to obtain material 2.

[0171] The stirring time, stirring temperature, and stirring rate in step two are the same as in step one.

[0172] Step 3: Add 40 parts of isooctyl acrylate to material 2 and stir evenly to obtain material 3.

[0173] The stirring time, stirring temperature, and stirring rate in step three are the same as in step one.

[0174] Step 4: Slowly add 0.4 parts of MDI to material 3 over a period of 1 hour at a reaction temperature of 90°C to obtain material 4.

[0175] In step four, the stirring speed is 150 rpm.

[0176] Step 5: Add 0.05 parts of 1-hydroxycyclohexylphenyl ketone to material 4 in the LED cadmium yellow lamp light source production environment to obtain UV anti-tack pressure-sensitive adhesive.

[0177] The stirring time, stirring temperature, and stirring rate in step five are the same as in step one.

[0178] Comparative Example 3

[0179] A commercially available UV anti-sticking adhesive for use in wafer dicing.

[0180] The UV-resistant adhesive used in this comparative example is a product of Dongguan Yizhou Adhesive Products Co., Ltd.

[0181] Application Examples

[0182] The UV-resistant pressure-sensitive adhesives prepared in Examples 1-5 and Comparative Examples 1-3 were coated into tapes and their performance was tested. Additionally, a UV-resistant film was prepared using the UV-resistant pressure-sensitive adhesives provided in Examples 1-5 and Comparative Examples 1-3. This UV-resistant film comprises a substrate layer, a UV-resistant layer, and a release film layer sequentially laminated together. The UV-resistant layer is formed by coating the UV-resistant pressure-sensitive adhesive onto the surface of the substrate layer, and the release film layer is laminated onto the UV-resistant layer. Specifically, the UV-resistant layer is obtained by coating the UV-resistant pressure-sensitive adhesive onto the surface of the substrate layer and then drying and curing it. The release film is a PET film, the base film is a PVC film, the thickness of the release film is 40 μm, the thickness of the base film is 70 μm, and the thickness of the UV-resistant layer is 15 μm.

[0183] The preparation method of UV anti-adhesion film includes the following steps:

[0184] The UV-resistant pressure-sensitive adhesives obtained in Examples 1-5 and Comparative Examples 1-3 were coated onto 70 μm thick PVC films and then baked in a drying device at 90-120°C for 2-5 minutes. A release film was then laminated onto the UV-resistant pressure-sensitive adhesive surface and the film was cured in a 55°C oven for 12 hours to obtain a UV-resistant film. The coating thickness of the UV-resistant pressure-sensitive adhesive can be adjusted according to actual needs. In the embodiments of this disclosure, the thickness of the UV-resistant layer after drying is 15 μm.

[0185] A standard sample of UV anti-adhesive film was prepared and tested according to GB / T2792-2014 "Test method for peel strength of adhesive tape". The test results are shown in Table 1.

[0186] Table 1

[0187]

[0188] Since the UV anti-adhesion pressure-sensitive adhesive prepared in this embodiment is mainly used in the wafer processing field, this disclosure uses a silicon wafer instead of a stainless steel plate for equivalent testing based on GB / T2792-2014 "Test Method for Peel Strength of Adhesive Tapes". A standard sample of the UV anti-adhesion film was prepared and tested, and the test results are shown in Table 2. The surface roughness Ra of the wafer used was 502.9 nm.

[0189] Table 2

[0190]

[0191] According to the test results in Tables 1 and 2, the UV anti-tack films prepared using the UV anti-tack pressure-sensitive adhesives of Examples 1 to 5 exhibit significantly higher 90° room temperature peel strength and 180° peel strength compared to Comparative Examples 1 to 3, indicating that the UV anti-tack pressure-sensitive adhesives prepared in this disclosure have higher peel strength. Furthermore, the curing activity of the UV anti-tack films prepared using the UV anti-tack pressure-sensitive adhesives of Examples 1 to 5 is significantly higher than that of Comparative Examples 1 to 3, with Example 1 showing the highest curing activity and requiring the lowest energy (300 mJ / cm²). 2 The fact that it can be cured instantly without leaving any residue indicates that the UV-resistant pressure-sensitive adhesive prepared in this embodiment has high curing activity. In other words, the components—bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound, 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, pentaerythritol acrylate, isophorone diisocyanate, acrylate diluent, and photoinitiator—need to be used in combination to achieve the comprehensive performance of the UV-resistant pressure-sensitive adhesive. Replacing similar components cannot achieve the superior effects of this embodiment.

[0192] Of course, the above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present disclosure should be included within the protection scope of the present disclosure.

Claims

1. A UV-resistant pressure-sensitive adhesive, characterized in that, The components include the following parts by weight: The mixture contains 8-25 parts of bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound, 13-35 parts of 1,6-hexanediol diglycidyl ether acrylate ring-opening compound, 8-20 parts of pentaerythritol acrylate, 0.1-3.5 parts of isophorone diisocyanate, 25-65 parts of acrylate diluent, and 0.01-0.5 parts of photoinitiator.

2. The UV-resistant pressure-sensitive adhesive according to claim 1, characterized in that, The bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compound is a ring-opening synthesis of bisphenol A epoxy or bisphenol F epoxy resin with an epoxy equivalent ≤186 obtained by recrystallization purification and acrylic acid.

3. The UV-resistant pressure-sensitive adhesive according to claim 1, characterized in that, The 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound is a ring-opening synthesis of 1,6-hexanediol diglycidyl ether and acrylic acid with an epoxy value of 0.65-0.7%.

4. The UV-resistant pressure-sensitive adhesive according to claim 1, characterized in that, The pentaerythritol acrylate has a specific gravity of 1.172, a refractive index of 1.4841, and an acid value of 0.17 mg KOH / g.

5. The UV-resistant pressure-sensitive adhesive according to claim 1, characterized in that, The isophorone diisocyanate has an isocyanate group mass fraction ≥37.5%, color ≤30, hydrolyzed chlorine ≤200mg / kg, and total chlorine ≤400mg / kg.

6. The UV-resistant pressure-sensitive adhesive according to claim 1, characterized in that, The acrylate diluent includes at least one of butyl acrylate, isooctyl acrylate, isodecyl acrylate, octadecyl acrylate, and dodecyl methacrylate.

7. A method for preparing a UV-resistant pressure-sensitive adhesive according to any one of claims 1 to 6, characterized in that, The steps are as follows: According to the weight parts of each component, the 1,6-hexanediol diglycidyl ether acrylate ring-opening compound and the bisphenol A epoxy or bisphenol F epoxy acrylate ring-opening compound are mixed evenly to obtain material 1; The pentaerythritol acrylate was added to material 1 and mixed evenly to obtain material 2; The acrylate diluent is added to material 2 and mixed evenly to obtain material 3; The isophorone diisocyanate was added dropwise to material 3 over a period of 45–75 min at a reaction temperature of 75–85 °C to obtain material 4. The photoinitiator was added to material 4 under the light source of a light-emitting diode (LED) cadmium yellow lamp to obtain the UV-resistant pressure-sensitive adhesive.

8. The preparation method according to claim 7, characterized in that, The preparation method further includes: Acrylic acid was added to 1,6-hexanediol diglycidyl ether, followed by the addition of a first polymerization inhibitor and a first catalyst. The reaction time was 3.5–4.5 h, and the reaction temperature was 80–120 °C, to obtain the 1,6-hexanediol diglycidyl ether acrylic acid ring-opening compound.

9. The preparation method according to claim 7, characterized in that, The preparation method further includes: Bisphenol A or bisphenol F epoxy resin was dissolved in a mixed solvent of n-heptane and ethyl acetate, and then separated by recrystallization to obtain bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182. Acrylic acid is added to the bisphenol A or bisphenol F epoxy resin with an epoxy equivalent of 176-182, and then a second polymerization inhibitor and a second catalyst are added. The reaction time is 5-6 hours and the reaction temperature is 75-110°C to obtain the bisphenol A epoxy or bisphenol F epoxy acrylic ring-opening compound.

10. The application of the UV-resistant pressure-sensitive adhesive according to any one of claims 1 to 6 in wafer processing.

Images