Adhesive composition for bonding different substrates and product thereof

Abstract

The invention relates to the technical field of adhesives, in particular to an adhesive composition for bonding different base materials and a product thereof. The adhesive composition for bonding different base materials comprises the following components in parts by weight: 55-65 parts of a component A, 22-36 parts of a component B, 9-13 parts of a component C, 0.5-1.5 parts of a first curing agent and 0.5-2 parts of a second curing agent, wherein the total part number of the component A, the component B and the component C is 100. According to the invention, by adopting the resin combination of different components, the adhesive has excellent adhesive force for bonding of different substrates, and the adhesive after thermocuring has excellent bonding strength, shear strength and impact strength.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to an adhesive composition for bonding different substrates and a product thereof. Background Art

[0002] Adhesive is a commonly used adhesive material. Existing adhesives are often used to bond the same or similar substrates, such as plastic to plastic, metal to metal, and leather to leather. Although there are also adhesives for different types of substrates, the applicable adhesives are generally developed to meet special scenarios and are not universal, resulting in a narrow range of applications.

[0003] With the improvement of adhesive bonding strength and its ease of use, adhesives are now widely used in different industries such as automobiles and home appliances, especially for the bonding of semiconductor devices and electronic components. Many of these devices involve the bonding between plastics and metals, and the surface energy between plastics and metals is quite different, and the surface energy between different plastics and different metals is also quite different. Current adhesives have the problems of insufficient bonding strength and poor universality.

[0004] At the same time, the existing semiconductor devices and electronic components have higher requirements for manufacturing accuracy and integration, requiring adhesives to achieve pre-positioning and stable bonding after positioning. Heat-activated adhesives are bonded by heating to generate viscosity. The resin components contained in the adhesive are solid at room temperature. When the temperature reaches the activation temperature, the thermal activation reaction of the resin will be triggered, thereby achieving high-strength bonding with the surface of the object to be bonded. Adhesive resins are divided into stages A, B, C and D according to the degree of curing. The resin in stage A is liquid; stage B is a semi-cured state, that is, the original state is solid, and it turns into a fluid at high temperature. It has precise positioning and excellent adhesion, and is widely used in precision electronic products; while stages C and D are in a cured state and do not play a bonding role.

[0005] In view of this, the present invention particularly proposes an adhesive composition for bonding different substrates and a product thereof. Summary of the invention

[0006] The present invention provides an adhesive composition for bonding different substrates, which can be used for bonding homogeneous or heterogeneous substrates, has good universality, and the cured adhesive has excellent peel strength, shear strength and impact strength.

[0007] In order to achieve the above-mentioned object of the present invention, the first aspect of the present invention provides an adhesive composition for bonding different substrates, comprising the following components in parts by weight:

[0008]

[0009] Wherein, the total number of components A, B and C is 100;

[0010] The component A is a combination of a first epoxy resin and a first polyester resin;

[0011] The component B is a combination of a second epoxy resin and a second polyester resin;

[0012] The component C is a heat-activated polyurethane resin;

[0013] The first curing agent is an isocyanate curing agent;

[0014] The second curing agent is a latent curing agent.

[0015] Furthermore, the glass transition temperature (Tg) of the first epoxy resin is ≥ 60° C. Furthermore, the epoxy equivalent of the first epoxy resin is 2,200 to 3,900 g / eq.

[0016] Furthermore, the glass transition temperature of the first polyester resin is ≥60°C.

[0017] Furthermore, the glass transition temperature of the second epoxy resin is -20 to 5° C. Furthermore, the epoxy equivalent of the second epoxy resin is 170 to 225 g / eq.

[0018] Furthermore, the glass transition temperature of the second polyester resin is -20 to 5°C.

[0019] Furthermore, the glass transition temperature of the heat-activated polyurethane resin is ≤-45°C.

[0020] Furthermore, the first polyester resin contains a combination of carboxyl and hydroxyl groups.

[0021] Furthermore, the isocyanate curing agent includes at least one of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), TDI trimer, HDI trimer and IPDI trimer.

[0022] Furthermore, the latent curing agent includes at least one of an amine curing agent and an acid anhydride curing agent. The amine curing agent includes at least one of a modified aliphatic amine curing agent, an aromatic amine curing agent, and a dicyandiamide curing agent.

[0023] The second aspect of the present invention provides an adhesive product, comprising a release layer and an adhesive layer disposed on one side of the release layer; the adhesive layer is mainly made of the adhesive composition described in the first aspect of the present invention.

[0024] Furthermore, the thickness of the adhesive layer is 50-100 μm.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The adhesive composition for bonding different substrates of the present invention adopts a combination of resins with different glass transition temperatures and adjusts the amount of each component, so that the adhesive can be used not only for bonding homogeneous substrates but also for bonding different substrates. At the same time, the adhesive after thermal curing has excellent peel strength, shear strength and impact strength;

[0027] (2) The adhesive product prepared by using the adhesive composition of the present invention not only significantly improves the bonding strength, shear strength and impact strength of the adhesive to homogeneous and heterogeneous bonding substrates, but also improves the universality of the adhesive product. DETAILED DESCRIPTION

[0028] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0029] In the description of the present invention, the terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0030] The first aspect of the present invention provides an adhesive composition for bonding different substrates, comprising the following components in parts by weight:

[0031]

[0032] Wherein, the total number of components A, B and C is 100;

[0033] The component A is a combination of a first epoxy resin and a first polyester resin;

[0034] The component B is a combination of a second epoxy resin and a second polyester resin;

[0035] The component C is a heat-activated polyurethane resin;

[0036] The first curing agent is an isocyanate curing agent;

[0037] The second curing agent is a latent curing agent.

[0038] In order to develop an adhesive composition that has good adhesion to both the same and different substrates and has a good balance between peel strength and mechanical strength after curing, the inventors have conducted in-depth research. The inventors of the present invention have found that by combining the resins of the components defined in the present invention, with a certain amount of isocyanate curing agent that can achieve low-temperature pre-curing and a heat-activated latent curing agent, the adhesive not only has excellent adhesion to both the same and different substrates, but also has excellent peel strength, shear strength and impact strength after thermal curing.

[0039] The adhesive composition of the present invention has an isocyanate curing agent that can undergo a cross-linking reaction with a portion of the first polyester resin and the second polyester resin in a low-temperature pre-curing stage, thereby improving the cohesive force of the adhesive film and providing the adhesive with better initial adhesion to achieve pre-lamination positioning; in a hot pressing curing stage, the latent curing agent and the heat-activated polyurethane resin are activated by heat, which can promote the adhesive system to undergo cross-linking to form a network structure, so that the cured adhesive has excellent peel strength and mechanical strength; and the first polyester resin, the second polyester resin and the heat-activated polyurethane resin contain highly reactive polar groups, which can have good adhesion to both metal substrates and plastic substrates.

[0040] In a specific embodiment of the present invention, the Tg of the first epoxy resin is not less than 60° C. The present invention stipulates that the Tg value of the first epoxy resin is relatively high, and the first epoxy resin as the main component can ensure that the adhesive has good high temperature resistance.

[0041] In a specific embodiment of the present invention, the epoxy equivalent of the first epoxy resin is not less than 2,200 g / eq, preferably not less than 2,500 g / eq, and not more than 3,900 g / eq, preferably not more than 3,300 g / eq. The "epoxy equivalent" described in the present invention refers to the number of grams of epoxy resin containing one equivalent of epoxy groups. The higher the value, the lower the proportion of epoxy groups. The first epoxy resin in the present invention has a higher epoxy equivalent, indicating that its epoxy group proportion is lower, which can avoid excessive internal crosslinking of the adhesive and loss of bonding performance. The epoxy equivalent test method of the epoxy resin of the present invention is tested in accordance with the international standard ASTMD1652-11 "Standard Test Method for Epoxy Equivalent of Epoxy Resins".

[0042] In a specific embodiment of the present invention, the first polyester resin contains carboxyl and hydroxyl functional groups. In the low-temperature pre-curing stage, the first polyester resin containing carboxyl and hydroxyl groups will be cross-linked with the isocyanate curing agent to make the adhesive have initial adhesion that meets the pre-positioning requirements.

[0043] In a specific embodiment of the present invention, the Tg of the first polyester resin is not less than 60° C. The high Tg value of the first polyester resin can ensure that the adhesive has good high temperature resistance.

[0044] In a specific embodiment of the present invention, the epoxy equivalent of the second epoxy resin is not less than 170 g / eq and not more than 225 g / eq, preferably not more than 210 g / eq. The epoxy equivalent of the second epoxy resin is relatively low, indicating that it contains more epoxy groups, so that there are more epoxy ring-opening crosslinks, which improves the internal crosslinking degree of the adhesive during the hot pressing curing stage, and ensures that the adhesive has good shear strength and impact resistance after curing.

[0045] In a specific embodiment of the present invention, the Tg of the second epoxy resin is not lower than -20°C, preferably not lower than -18°C, and not higher than 5°C, preferably not higher than 3°C. The Tg value of the second epoxy resin in the present invention is relatively low, which can make the adhesive have a certain flexibility and prevent the adhesive from being too hard after curing and losing its bonding performance.

[0046] In a specific embodiment of the present invention, the Tg of the second polyester resin is not lower than -20°C and not higher than 5°C, preferably not higher than 0°C. The low Tg value of the second polyester resin in the present invention can make the adhesive have a certain flexibility and prevent the adhesive from being too hard after curing and losing its bonding performance.

[0047] In a specific embodiment of the present invention, the Tg of the heat-activated polyurethane resin is not higher than -45° C., preferably not higher than -50° C. The low Tg value of the heat-activated polyurethane resin in the present invention can make the adhesive have a certain flexibility and prevent the adhesive from being too hard after curing and losing its bonding properties.

[0048] In a specific embodiment of the present invention, the isocyanate curing agent includes at least one of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), TDI trimer, HDI trimer and IPDI trimer. Introducing a certain amount of isocyanate curing agent into the adhesive system can enable the adhesive of the present invention to be pre-cured at low temperature, so that the adhesive has initial adhesion that meets the pre-positioning requirements.

[0049] In a specific embodiment of the present invention, the latent curing agent includes at least one of an amine curing agent and an acid anhydride curing agent. The amine curing agent includes at least one of a modified aliphatic amine curing agent, an aromatic amine curing agent, and a dicyandiamide curing agent. The latent curing agent triggers a heat-activated reaction during the hot pressing process, and improves the bonding strength, shear strength and impact strength of the adhesive through thermal curing.

[0050] For example, in different embodiments, in the adhesive composition, the amounts of the components in parts by weight may be as follows:

[0051] The amount of component A can be 55 parts, 58 parts, 60 parts, 62 parts, 65 parts or any value between the two ends thereof; the amount of the first epoxy resin in component A is 10-20 parts, specifically 10 parts, 13 parts, 15 parts, 17 parts, 20 parts or any value between the two ends thereof; the amount of the first polyester resin in component A is 40-50 parts, specifically 40 parts, 43 parts, 45 parts, 47 parts, 50 parts or any value between the two ends thereof; the amount of component A is adjusted within the above range, and the high Tg first epoxy resin and the first polyester resin can ensure that the adhesive The adhesive has excellent bonding performance and high temperature resistance, and has excellent shear strength and impact resistance for bonding to different substrates; the amount of the first epoxy resin in component A is limited within the above range, and a high-density cross-linking network can be formed after solidification to ensure the bonding strength and rigidity of the adhesive, and to ensure that the adhesive product has a certain temperature resistance; the amount of the first polyester resin in component A is limited within the above range, so that the adhesive has excellent bonding performance for different substrates and has a certain toughening effect, and can prevent the first epoxy resin from being highly cross-linked after thermal curing, which may cause the adhesive product to be too hard and brittle and cause performance degradation.

[0052] The amount of component B can be 22 parts, 28 parts, 30 parts, 32 parts, 36 parts or any value between the two ends; the amount of the second epoxy resin in component B is 10-16 parts, specifically 10 parts, 11 parts, 13 parts, 15 parts, 16 parts or any value between the two ends; the amount of the second polyester resin in component B is 12-20 parts, specifically 12 parts, 14 parts, 16 parts, 18 parts, 20 parts or any value between the two ends; when the amount of component B is adjusted within the above range, the Tg value of component B is low, and a Tg gradient is formed with the resin in component A with a high Tg value. The components with varying degrees of change can optimize the bonding performance of the adhesive. During the hot pressing process of bonding different substrates, the fluidity of the adhesive is increased, and it can better penetrate into the surface of the adherend, thereby improving the bonding strength and durability; the amount of the second epoxy resin in component B is limited to the above range, and the cross-linking and curing of the second epoxy resin and the amine curing agent during the hot pressing process can improve the bonding performance and curing speed of the adhesive; the amount of the second polyester resin in component B is limited to the above range, and the second polyester resin can be cured with an isocyanate curing agent to improve the bonding performance, and has good toughness and adhesion to different substrates.

[0053] The amount of component C can be 9 parts, 10 parts, 11 parts, 12 parts, 13 parts or any value between any two end values; by adjusting the amount of component C within the above range, it can be ensured that the adhesive product material will not become brittle or hard in a low temperature environment, the bonding performance is guaranteed, and an interpenetrating network structure with both rigidity and elasticity is formed between the first epoxy resin and the second epoxy resin, which can improve the shear strength and impact strength of the adhesive;

[0054] Wherein, the total number of components A, B and C is 100;

[0055] The amount of the first curing agent can be 0.5 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts or any value between any two ends thereof;

[0056] The amount of the second curing agent can be 0.5 parts, 0.8 parts, 1 part, 1.5 parts, 2 parts or any value in between.

[0057] In a specific embodiment of the present invention, the adhesive composition may further include a solvent. Further, the solvent includes but is not limited to methyl ethyl ketone (MEK). The amount of the solvent can be adjusted according to different coating solids.

[0058] In the present invention, there is no restriction on the preparation method of the adhesive, and a commonly used preparation method of the adhesive can be used. The present invention provides a preparation method of an adhesive, comprising the adhesive composition described in the first aspect of the present invention, and comprising the following steps: mixing the components in proportion, stirring evenly, and then standing to defoam, to obtain the adhesive to be coated.

[0059] In a specific embodiment of the present invention, the preparation method further comprises: uniformly mixing the solvent with the components until the solid content is 35% to 45%, thereby obtaining the adhesive to be coated.

[0060] It is understandable that, in order to facilitate production, transportation and sales, the adhesive composition of the present invention only limits the composition of the components but does not limit the existence form of the components, that is, the components can be mixed with each other or stored separately. The mixed or separate storage mode can be selected according to the actual use time.

[0061] The second aspect of the present invention provides an adhesive product, comprising a release layer and an adhesive layer disposed on one side of the release layer; the adhesive layer is mainly made of the adhesive composition described in the first aspect of the present invention.

[0062] In a specific embodiment of the present invention, the thickness of the adhesive layer is 50 to 100 μm, for example, 50 μm, 60 μm, 70 μm, 80 μm, 100 μm or any value between the two ends. If the thickness of the adhesive layer in the present invention is too thin, it is difficult to ensure the bonding strength; if it is too thick, it is difficult to ensure sufficient curing in the thermal curing stage, thereby affecting the shear strength after curing.

[0063] The present invention also provides an optional preparation method of the above adhesive product, comprising the following steps: coating the adhesive on the surface of the release layer, and drying to obtain the adhesive product.

[0064] The coating method is not limited, and conventional coating methods such as roller coating, blade coating or dip coating can be used. The thickness of the release layer can be freely selected according to actual needs, and there is no special limitation. For example, it can be set to 25 to 100 μm, and specifically can be 25 μm, 30 μm, 40 μm, 50 μm, 80 μm, 100 μm or any value between the two ends.

[0065] In a specific embodiment of the present invention, the drying process comprises: drying at 60-80° C. for 6-10 minutes.

[0066] When the adhesive product of the present invention is actually used, the release layer can be torn off first, pre-laminated on the surface of the object to be bonded, and then hot-pressed; wherein the pre-lamination temperature is 60-70°C; during the hot-pressing treatment, the temperature is 90-130°C, the pressure is 0.5Mpa-1.5Mpa, and the hot-pressing time is 30-300s.

[0067] In practical applications, the adhesive product of the present invention can be used for bonding substrates such as polycarbonate (PC), polyethylene terephthalate (PET), aluminum (Al), etc. In order to facilitate the thermal curing of the adhesive, the thickness of the bonding substrate is generally not more than 2 cm.

[0068] The following specific examples are listed to further illustrate the purpose and advantages of the present invention, but these examples should not be regarded as limiting the present invention. In the following examples, 1g represents 1 part by weight. The Tg values ​​of some raw materials in the following examples are obtained by the inventor according to differential scanning calorimetry (DSC).

[0069] Example 1

[0070] The adhesive provided in this embodiment includes the following components:

[0071] Component A: The first epoxy resin uses 10g of YD-019C produced by Guodu Chemical (Kunshan) Co., Ltd., with an epoxy equivalent of 2,500-3,300g / eq and a Tg of 70°C; the first polyester resin uses 40g of V2200B (hydroxyl-containing polyester resin), with a self-measured Tg of 69°C, and 10g of SJ4700 (carboxyl-terminated polyester resin) produced by Anhui Shenjian New Materials Co., Ltd., with a self-measured Tg of 60°C;

[0072] Component B: The second epoxy resin is 12g produced by Huntsman, USA EPN1179 # , the epoxy equivalent is 170-180 g / eq, and its Tg is -12.5°C; the second polyester resin uses 18g of XCP-R2170 produced by Asahikawa Chemical (Suzhou) Co., Ltd., and its Tg is -15°C;

[0073] Component C: 10g XCT-L95070 produced by Asahikawa Chemical (Suzhou) Co., Ltd., with a self-measured Tg of -50°C;

[0074] First curing agent: 1g produced by Shandong Wanhua Chemical Co., Ltd. IT-170B;

[0075] Second curing agent: 1g produced by Huntsman, USA 5200.

[0076] The preparation method of the adhesive is as follows: the above materials are mixed uniformly according to proportion, and a proper amount of MEK is added to dilute the mixture to a solid content of 40% to obtain the adhesive to be coated.

[0077] Example 2

[0078] This example is carried out with reference to Example 1, with the only difference being that the amounts of the components in the adhesive are different, and the adhesive composition and preparation method are the same as those in Example 1, with specific differences as shown below.

[0079] The adhesive of this embodiment includes the following components:

[0080] Component A: 15g of YD-019C, 35g of V2200B and 5g of SJ4700 polyester resin;

[0081] Component B: 16g EPN 1179 # , 20g of XCP-R2170;

[0082] Component C: 9 g of XCT-L95070;

[0083] First curing agent: 1.5g IT-170B;

[0084] Second curing agent: 0.5g 5200.

[0085] Example 3

[0086] This example is carried out with reference to Example 1, with the only difference being that the amounts of the components in the adhesive are different, and the adhesive and its preparation method are the same as those in Example 1, with the specific differences being as follows.

[0087] The adhesive of this embodiment includes the following components:

[0088] Component A: 20g of YD-019C, 30g of V2200B and 15g SJ4700;

[0089] Component B: 10g EPN 1179 # and 12g of XCP-R2170;

[0090] Component C: 13 g of XCT-L95070;

[0091] First curing agent: 0.5g IT-170B;

[0092] Second curing agent: 2g 5200.

[0093] Example 4 Group

[0094] This embodiment group was carried out with reference to the embodiment 1, except that the adhesive used the same amount of the second epoxy resin with different Tg and different epoxy equivalent, and the other components of the adhesive and the preparation method thereof were the same as those in the embodiment 1, and the specific differences are as follows:

[0095] Example 4a: The second epoxy resin is NPPN-683S produced by Nan Ya Plastics Industrial Co., Ltd., with an epoxy equivalent of 170-190 g / eq and a Tg of 3°C;

[0096] Example 4b: The second epoxy resin is produced by Huntsman Corporation of the United States EPN1180 # , its epoxy equivalent is 175~182g / eq, and Tg is 6℃;

[0097] Example 4c: The second epoxy resin is produced by DIC Corporation of Japan EXA-830LVP, its epoxy equivalent is 156-168g / eq, and its Tg is -10℃;

[0098] Example 4d: The second epoxy resin is produced by DIC Corporation of Japan 860, its epoxy equivalent is 235-255 g / eq, and its Tg is -15°C;

[0099] Example 4e: The second epoxy resin is produced by Huntsman Corporation of the United States 8250Cl, its epoxy equivalent is 160-178 g / eq, and its Tg is -18°C;

[0100] Example 4f: The second epoxy resin is ERS-133 produced by Shanghai Zhongsi Industrial Co., Ltd., which has an epoxy equivalent of 230-240 g / eq and a Tg of -22°C.

[0101] Example 5 Group

[0102] This example group was carried out with reference to Example 1, except that the adhesive used an equal amount of a second polyester resin with a different Tg, and the other components of the adhesive and the preparation method thereof were the same as those of Example 1, with the specific differences being as follows:

[0103] Example 5a: The second polyester resin is produced by Bostik Corporation of the United States 1916NSB, Tg self-measured is -2℃;

[0104] Example 5b: The second polyester resin is produced by Bostik Corporation of the United States 1800, Tg self-measured is -20℃;

[0105] Example 5c: The second polyester resin is produced by Bostik Corporation of the United States 3200B, Tg self-measured is 15℃;

[0106] Example 5d: The second polyester resin is XCP-R2370 produced by Asahikawa Chemical (Suzhou) Co., Ltd., and its Tg is -30°C.

[0107] Comparative Example 1

[0108] This comparative example group was prepared with reference to Example 1, except that the first epoxy resin with different Tg and different epoxy equivalent was used in the adhesive, and the other components of the adhesive and the preparation method thereof were the same as those in Example 1, and the specific differences are as follows:

[0109] Comparative Example 1a: The first epoxy resin is YD-017 produced by Guodu Chemical (Kunshan) Co., Ltd., whose epoxy equivalent is 1,750-2,100 g / eq and whose Tg is 50°C;

[0110] Comparative Example 1b: The first epoxy resin is produced by DIC Corporation of Japan 7070-40K, its epoxy equivalent is 1,700-2,100 g / eq, and its Tg is 62°C;

[0111] Comparative Example 1c: The first epoxy resin is KD-2620BCX40 produced by Guodu Chemical (Kunshan) Co., Ltd., with an epoxy equivalent of 4,000 to 6,000 g / eq and a Tg of 75°C.

[0112] Comparative Example 2

[0113] This comparative example group was prepared with reference to Example 1, except that the same amount of first polyester resins with different Tgs were used in the adhesive, and the other components of the adhesive and the preparation method thereof were the same as those in Example 1, with the specific differences being as follows:

[0114] Comparative Example 2a: The first polyester resin is made of a polyester resin from Bostik Corporation of the United States. 2700B Replacement 2200B, its Tg is self-measured at 50°C;

[0115] Comparative Example 2b: SJ5701 produced by Anhui Shenjian New Materials Co., Ltd. was used in the first polyester resin instead of SJ4700, and its Tg was 50°C.

[0116] Comparative Example 3

[0117] This comparative example group was prepared with reference to Example 1, except that: the adhesive used a heat-activated polyurethane resin with different Tg or different dosage, and in order to keep the total amount of component A, component B and component C unchanged, the dosage of component B was adjusted accordingly. The other components of the adhesive and the preparation method thereof were the same as those in Example 1, and the specific differences are as follows:

[0118] Comparative Example 3a: Component C is produced by Covestro Polymers (China) Co., Ltd. 445 was used instead, and its Tg was self-measured to be -40°C;

[0119] Comparative Example 3b: XCT-L95070 in component C is 6g, and EPN 1179 # 16g;

[0120] Comparative Example 3c: The amount of XCT-L95070 in component C is 16 g, and the amount of XCP-R2170 in component B is 12 g.

[0121] Comparative Example 4

[0122] This comparative example group was prepared with reference to Example 1, except that the composition of component A in the adhesive was different, and the other components of the adhesive and their preparation methods were the same as those in Example 1. The specific differences are as follows:

[0123] Comparative Example 4a: 5g of YD-019C, 45g of SJ4700 with 2200B and 10g;

[0124] Comparative Example 4b: 25g of YD-019C, 25g of SJ4700 with 2200B and 10g;

[0125] Comparative Example 4c: 10g of YD-019C and 50g of 2200B, excluding SJ4700;

[0126] Comparative Example 4d: 10g of YD-019C and 50g of SJ4700, without 2200B.

[0127] Comparative Example 5

[0128] This comparative example group was prepared with reference to Example 1, except that the composition of component B in the adhesive was different, and the other components of the adhesive and the preparation method thereof were the same as those in Example 1, and the specific differences are as follows:

[0129] Comparative Example 5a: 18g EPN 1179 # and 12g of XCP-R2170;

[0130] Comparative Example 5b: 8g EPN 1179 # and 22g of XCP-R2170;

[0131] Comparative Example 5c: 20 g EPN 1179 # and 10g of XCP-R2170.

[0132] Comparative Example 6

[0133] This comparative example group was prepared with reference to Example 1, except that the amount of the first curing agent or the second curing agent in the adhesive was different, and the other components of the adhesive and the preparation method thereof were the same as those in Example 1, and the specific differences are as follows:

[0134] Comparative Example 6a: 0.3 g IT-170B;

[0135] Comparative Example 6b: 1.7 g IT-170B;

[0136] Comparative Example 6c: 0.3 g 5200;

[0137] Comparative Example 6d: 2.3 g 5200.

[0138] Test Case

[0139] The adhesives prepared in the above embodiments and comparative examples were used to prepare adhesive products in the following manner: the above adhesives were applied to the surface of a 50 μm thick non-silicon release film by knife coating, and placed in a 65°C oven for 6 minutes to form an adhesive product with an adhesive layer thickness of 50 μm. A 2 cm × 3 cm sample of the adhesive product was taken, the release film was torn off, the film was attached between two substrates to be tested (the thickness of the substrates was 5 mm), pre-pressed on a hot plate at 70°C, and then laminated at 120°C and 0.5 MPa for 5 minutes, and then cooled to room temperature (25°C), and the following tests were performed. The test results are shown in Table 1.

[0140] Shear strength: Tested in accordance with the national standard GB / T 33332-2016 "Test method for dynamic shear strength of adhesive tapes". In order to meet the product use requirements, the shear strength of the adhesive on the same plastic substrate (such as PC board and PC board, PET board and PET board) needs to be no less than 8MPa, the shear strength of the adhesive on different substrates (such as PET board and Al board, PC board and Al board) needs to be no less than 16MPa, and the shear strength of the adhesive on the same metal substrate (such as Al board and Al board) needs to be no less than 25MPa.

[0141] Impact strength: Tested in accordance with the national standard GB / T 6328-2021 "Adhesive Shear Impact Strength Test Method". In order to meet the product use requirements, the impact strength of the adhesive on the same plastic substrate (such as PC board and PC board, PET board and PET board) needs to be no less than 2J, the impact strength of the adhesive on different substrates (such as PET board and Al board, PC board and Al board) needs to be no less than 2.3J, and the impact strength of the adhesive on the same metal substrate (such as Al board and Al board) needs to be no less than 2.5J;

[0142] Peel strength: Tested in accordance with the national standard GB / T 2792-2014 "Test method for peel strength of adhesive tapes". In order to meet the product use requirements, the peel strength of the adhesive for the same plastic substrate (such as PC board and PC board, PET board and PET board) needs to be no less than 40N / mm, the peel strength of the adhesive for different substrates (such as PET board and Al board, PC board and Al board) needs to be no less than 43N / mm, and the peel strength of the adhesive for the same metal substrate (such as Al board and Al board) needs to be no less than 45N / mm.

[0143] Table 1 Test results of different embodiments and comparative examples

[0144]

[0145]

[0146] The above test results show that the adhesive obtained by combining components with different glass transition temperatures shows excellent performance and balance between shear strength, impact strength and peel strength when used for bonding the same and different substrates.

[0147] It can be seen from the test results of Example 4 that when the glass transition temperature or epoxy equivalent of the second epoxy resin in the adhesive does not meet the specified range of the present invention, the bonding effect on different substrates will decrease.

[0148] It can be seen from the test results of Example 5 that when the glass transition temperature of the second polyester resin in the adhesive exceeds the specified range of the present invention, the bonding performance of the adhesive will decrease.

[0149] It can be seen from the test results of Comparative Example 1 that when the epoxy equivalent or glass transition temperature of the first epoxy resin in the adhesive exceeds the specified range of the present invention, the bonding performance of the adhesive will decrease.

[0150] It can be seen from the test results of Comparative Example 2 that when the glass transition temperature of the first polyester resin in the adhesive is lower than the range specified in the present invention, the bonding performance of the adhesive will decrease.

[0151] It can be seen from the test results of Comparative Example 3 that when the glass transition temperature of the heat-activated polyurethane resin in the adhesive or its dosage exceeds the specified range of the present invention, the bonding performance of the adhesive will be affected.

[0152] From the test results of comparative example 4, it can be seen that when the amount of the first epoxy resin or the first polyester resin in component A of the adhesive exceeds the specified range, the bonding properties of the adhesive will be affected; and if the first polyester resin contains only one functional group, namely, carboxyl or hydroxyl, it will have a greater impact on the bonding properties of the adhesive.

[0153] It can be seen from the test results of Comparative Example 5 that when the amount of the second epoxy resin or the second polyester resin in component B of the adhesive exceeds the specified range, the bonding performance of the adhesive will be affected.

[0154] It can be seen from the test results of Comparative Example 6 that when the amount of the first curing agent or the second curing agent in the adhesive exceeds the specified range, the bonding performance of the adhesive will be affected.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adhesive composition for bonding different substrates, characterized in that: It includes the following components by weight: Wherein, the total number of components A, B and C is 100; The component A is a combination of a first epoxy resin and a first polyester resin; The component B is a combination of a second epoxy resin and a second polyester resin; The component C is a heat-activated polyurethane resin; The first curing agent is an isocyanate curing agent; The second curing agent is a latent curing agent.

2. The adhesive composition for bonding different substrates according to claim 1, characterized in that: In the component A, the first epoxy resin is used in an amount of 10 to 20 parts, and the first polyester resin is used in an amount of 40 to 50 parts; And / or, in the component B, the amount of the second epoxy resin is 10 to 16 parts, and the amount of the second polyester resin is 12 to 20 parts.

3. The adhesive composition for bonding different substrates according to claim 1 or 2, characterized in that: The glass transition temperature of the first epoxy resin is ≥60°C; And / or, the epoxy equivalent of the first epoxy resin is 2,200 to 3,900 g / eq.

4. The adhesive composition for bonding different substrates according to claim 1 or 2, characterized in that: The glass transition temperature of the first polyester resin is ≥60°C.

5. The adhesive composition for bonding different substrates according to claim 1 or 2, characterized in that: The glass transition temperature of the second epoxy resin is -20 to 5°C; And / or, the epoxy equivalent of the second epoxy resin is 170 to 225 g / eq.

6. The adhesive composition for bonding different substrates according to claim 1 or 2, characterized in that: The glass transition temperature of the second polyester resin is -20 to 5°C.

7. The adhesive composition for bonding different substrates according to claim 1, characterized in that: The glass transition temperature of the heat-activated polyurethane resin is ≤-45°C.

8. The adhesive composition for bonding different substrates according to claim 4, characterized in that: The first polyester resin contains a combination of carboxyl groups and hydroxyl groups.

9. An adhesive product, characterized in that: It comprises a release layer and an adhesive layer arranged on one side of the release layer; the adhesive layer is mainly made of the adhesive composition according to any one of claims 1 to 8.

10. The adhesive product according to claim 9, characterized in that: The thickness of the adhesive layer is 50-100 μm.

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