Rapidly curable adhesive compositions and articles thereof

Abstract

The invention relates to the technical field of adhesives, in particular to an adhesive composition capable of being rapidly cured and a product thereof. The adhesive composition capable of being rapidly cured is prepared from the following components in parts by weight: 40 to 50 parts of first epoxy resin, 20 to 30 parts of second epoxy resin, 20 to 40 parts of isophthalic unsaturated polyester resin, 0.2 to 1 part of first curing agent and 0.5 to 1.5 parts of second curing agent, wherein the total weight of the first epoxy resin, the second epoxy resin and the isophthalic unsaturated polyester resin is 100 parts. The adhesive prepared from the adhesive composition disclosed by the invention has the initial adhesion meeting the pre-pasting positioning requirement without being preheated; and after positioning, rapid curing can be realized through hot pressing for a short time (5-30 seconds), so that the adhesive has excellent shear strength and impact resistance.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to a fast-curing adhesive composition and a product thereof. Background Art

[0002] Heat-activated adhesives are adhesives that are bonded by heating to produce viscosity. The resin components contained in the adhesive are solid at room temperature. When the temperature reaches the activation temperature, the heat activation reaction of the resin is 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 have a bonding effect.

[0003] In the prior art, since the B-stage adhesive is solid and not sticky at room temperature, it needs to be pre-attached to the surface of the object to be bonded under medium-low temperature (50-80°C) heating conditions, and then hot-pressed under medium-high temperature (90-300°C) heating conditions to achieve bonding. This process has many steps, and in order to ensure the bonding strength of the adhesive, the hot-pressing time is relatively long, generally requiring 0.5 to 3 hours.

[0004] In view of this, the present invention particularly proposes an adhesive that can be cured quickly. Summary of the invention

[0005] The first aspect of the present invention provides a fast-curing adhesive composition, wherein the adhesive formed by the composition does not require a medium or low temperature preheating step, i.e., has initial bonding properties that meet the pre-lamination positioning requirements; after positioning, the adhesive can be rapidly cured in the B stage by short-time (5 to 30 seconds) hot pressing, and has excellent shear strength and impact strength.

[0006] In order to achieve the above-mentioned object of the present invention, the first aspect of the present invention provides a fast-curing adhesive composition, comprising the following components in parts by weight:

[0007]

[0008] Wherein, the total weight of the first epoxy resin, the second epoxy resin and the isophthalic unsaturated polyester resin is 100 parts;

[0009] The epoxy equivalent of the first epoxy resin is 2,000 to 3,000 g / eq; the second epoxy resin is an alicyclic epoxy resin;

[0010] The first curing agent contains a reactive double bond, and the second curing agent includes an amine curing agent and an acid anhydride curing agent.

[0011] Furthermore, the epoxy equivalent of the second epoxy resin is 120 to 200 g / eq.

[0012] Furthermore, the acid value of the isophthalic unsaturated polyester resin is 15 to 20 mgKOH / g.

[0013] Furthermore, the viscosity of the isophthalic unsaturated polyester resin is 850 to 1,200 mPa.s.

[0014] Furthermore, the mass ratio of the first epoxy resin to the second epoxy resin is (1.3-2.5):1.

[0015] Furthermore, the amount of the amine curing agent used is greater than the amount of the anhydride curing agent used.

[0016] Furthermore, the amine curing agent includes at least one of dicyandiamide, 4,4'-diaminodiphenylmethane and meta-phenylenediamine.

[0017] Furthermore, the acid anhydride curing agent includes at least one of methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride.

[0018] Furthermore, the first curing agent includes at least one of (meth)acrylate, maleate, fumarate, itaconate, allyl ester and diallyl phthalate.

[0019] Furthermore, the first epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, polyurethane modified epoxy resin and glycidyl ester epoxy resin.

[0020] The second aspect of the present invention provides an adhesive product, comprising a support layer and an adhesive layer disposed on at least one side of the support layer; the adhesive layer is mainly made of the fast-curable adhesive composition described in the first aspect of the present invention.

[0021] Furthermore, the thickness of the adhesive layer is 50-100 μm.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The adhesive composition of the present invention has initial bonding performance that meets the pre-lamination positioning requirements without preheating by compounding the various components; after positioning, it can be quickly cured by hot pressing treatment in a short time (5 to 30 seconds), and the prepared adhesive has excellent shear strength and impact strength, greatly shortening the B-stage curing time of the adhesive;

[0024] (2) The adhesive product prepared by using the adhesive composition of the present invention has an adhesive layer having excellent impact strength and shear strength after curing. DETAILED DESCRIPTION

[0025] 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.

[0026] In the description of the present invention, the terms “first”, “second”, etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0027] The first aspect of the present invention provides a fast-curing adhesive composition, comprising the following components in parts by weight:

[0028]

[0029] Wherein, the total weight of the first epoxy resin, the second epoxy resin and the isophthalic unsaturated polyester resin is 100 parts.

[0030] In the adhesive composition of the present invention, by introducing an appropriate amount of isophthalic unsaturated polyester resin and a first curing agent, compounding with other compositions can make the formed adhesive have good initial adhesion, and can achieve the effect of pre-lamination and positioning without preheating. In addition, in the hot pressing curing stage, the isophthalic unsaturated polyester resin can undergo a cross-linking reaction with the first curing agent and the second curing agent containing reactive double bonds, so that the adhesive can be quickly cured to form a dense cross-linked network structure, thereby improving the modulus and cohesion of the adhesive, and making it have higher shear strength and impact strength. The adhesive composition of the present invention is compounded with multiple components, so that the adhesive formed can achieve room temperature pre-lamination and positioning, hot pressing and rapid (5 to 30 seconds) curing, and has excellent impact strength and shear strength after curing.

[0031] In a specific embodiment of the present invention, the first epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, polyurethane modified epoxy resin and glycidyl ester epoxy resin, preferably bisphenol A epoxy resin.

[0032] In a specific embodiment of the present invention, the epoxy equivalent of the first epoxy resin is not less than 2,000 g / eq and not more than 3,000 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 of the present invention has a higher epoxy equivalent value, indicating that the proportion of epoxy groups in the epoxy resin is relatively low, which is conducive to the rapid cross-linking reaction between the reactive double bonds of the first epoxy resin and the isophthalic unsaturated polyester resin, thereby increasing the curing speed of the adhesive. The small amount of epoxy groups on the first epoxy resin can also be further cross-linked with amine or anhydride curing agents in the B-stage curing stage to form a denser cross-linking network to improve the shear strength and impact strength of the adhesive after curing.

[0033] In different embodiments, the first epoxy resin in the present invention can be a commercially available product, such as the epoxy resin produced by DIC Corporation of Japan. HM-091 (bisphenol A epoxy resin) has an epoxy equivalent of 2,200 to 2,900 g / eq; KD-2159 (bisphenol A epoxy resin) produced by Guodu Chemical (Kunshan) Co., Ltd. has an epoxy equivalent of 2,450 to 2,850 g / eq.

[0034] For example, in different embodiments, the amount of the first epoxy resin can be 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, or any value between any two end values. Controlling the amount of the first epoxy resin within the above range can not only ensure the initial adhesion of the adhesive with the other components, but also enable the first epoxy resin and the second curing agent to react quickly during the hot pressing stage, and after a short period of hot pressing, give the adhesive excellent shear strength and impact strength.

[0035] In a specific embodiment of the present invention, the second epoxy resin is an alicyclic epoxy resin. In the present invention, the alicyclic epoxy resin is used. Due to the reaction inertness of the alicyclic, the hydroxyl groups on the epoxy resin can quickly form a cross-linked network structure with the hydroxyl groups on the first epoxy resin, which helps to shorten the B-stage curing time; in addition, since the alicyclic has a certain rigidity, the heat resistance and impact resistance of the adhesive can be improved.

[0036] In a specific embodiment of the present invention, the epoxy equivalent of the second epoxy resin is not less than 120 g / eq and not more than 200 g / eq. The epoxy equivalent of the second epoxy resin is low, the hydroxyl content in its molecule is high, and the reaction activity is high, which is conducive to the rapid crosslinking of the second epoxy resin with the first epoxy resin and the anhydride curing agent.

[0037] The second epoxy resin of the present invention can be a commercially available product, such as CELLOXIDE 2021P (epoxy equivalent of 130 g / eq) and CELLOXIDE EHPE 3150CE (epoxy equivalent of 150 g / eq) produced by Daicel (China) Investment Co., Ltd.

[0038] For example, in different embodiments, the amount of the second epoxy resin can be 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, or any value between any two ends thereof. Limiting the amount of the second epoxy resin to the above range can, on the one hand, give the adhesive a rapid curing property during the hot pressing stage, and on the other hand, can improve the heat resistance and impact resistance of the product after hot pressing curing.

[0039] For example, in different embodiments, the mass ratio of the first epoxy resin to the second epoxy resin is (1.3-2.5):1, and specifically can be 1.3:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.3:1, 2.5:1 or any ratio within the range of the two end values. The inventors of the present invention have found that controlling the mass ratio of the first epoxy resin to the second epoxy resin within this range can ensure that the adhesive has good initial adhesion performance in the early stage, and after B-stage curing, the adhesive can have good shear strength and impact resistance.

[0040] In a specific embodiment of the present invention, the acid value of the isophthalic unsaturated polyester resin is not less than 15 mgKOH / g and not more than 20 mgKOH / g. The "acid value" in the present invention indicates the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of chemical substances. The higher the acid value, the stronger the acidity and the more free fatty acids it contains. When the acid value of the isophthalic unsaturated polyester resin used in the present invention is limited within this range, the degree of reaction crosslinking between the isophthalic unsaturated polyester resin and the first epoxy resin and the first curing agent can be controlled, thereby obtaining an adhesive with good initial adhesion.

[0041] In a specific embodiment of the present invention, the viscosity of the isophthalic unsaturated polyester resin at 23°C is not less than 850 mPa.s and not more than 1,200 mPa.s. When the viscosity of the isophthalic unsaturated polyester resin at 23°C used in the present invention is the viscosity at room temperature and is controlled within this range, it helps the adhesive to have a suitable initial adhesion.

[0042] In a specific embodiment of the present invention, the isophthalic unsaturated polyester resin of the present invention can be a commercially available product, such as the one produced by Jinling Liliansi Resin Co., Ltd. A 400-901, the acid value is measured according to the international standard ASTM D664-24 "Standard Test Method for Acid Value of Petroleum Products by Potentiometric Titration", which is 15-19 mgKOH / g; the viscosity at 23°C is measured according to the international standard ASTM D445-24 "Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids", which is 850-1,150 mPa.s.

[0043] In a specific embodiment of the present invention, the amount of the isophthalic unsaturated polyester resin can be 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts or any value between any two end values. The amount of the isophthalic unsaturated polyester resin in the present invention is controlled within the above range, which can not only improve the initial adhesion of the adhesive, but also balance the bonding strength of the adhesive after hot pressing and curing; and because it contains benzene rings, it has strong rigidity and good heat resistance, which can make the adhesive have good high temperature resistance.

[0044] In a specific embodiment of the present invention, the total weight of the first epoxy resin, the second epoxy resin and the isophthalic unsaturated polyester resin is 100 parts.

[0045] In a specific embodiment of the present invention, the first curing agent contains a reactive double bond. The first curing agent of the present invention acts as a plasticizer at room temperature, which can increase the viscosity of the adhesive, make the adhesive have initial viscosity, and achieve the pre-lamination positioning effect without preheating; and in the thermosetting stage, the reactive double bonds in the first curing agent are cross-linked with the isophthalic unsaturated polyester resin, which can increase the modulus and cohesion of the adhesive, and improve the bonding performance and mechanical strength of the adhesive after curing.

[0046] In a specific embodiment of the present invention, the first curing agent includes at least one of (meth)acrylate, maleate, fumarate, itaconate, allyl ester and diallyl phthalate, preferably diallyl phthalate.

[0047] In a specific embodiment of the present invention, the amount of the first curing agent is 0.2-1 part, specifically 0.2 part, 0.4 part, 0.5 part, 0.6 part, 0.8 part, 1 part or any value between any two ends thereof.

[0048] In a specific embodiment of the present invention, the second curing agent includes an amine curing agent and an acid anhydride curing agent. The second curing agent of the present invention adopts a compound of an amine curing agent and an acid anhydride curing agent, and the amine curing agent and the acid anhydride curing agent do not react at room temperature. After being heated in the hot pressing stage, the acid anhydride curing agent opens the carboxyl group formed by the acid anhydride ring to cross-link with the hydroxyl group of the epoxy resin, and the amine curing agent can promote the ring opening of the acid anhydride curing agent due to the alkaline amine contained. At the same time, the alkaline amine can also cross-link with the hydroxyl group of the epoxy resin, thereby increasing the curing speed and improving the bonding performance and impact resistance of the adhesive after curing.

[0049] In a specific embodiment of the present invention, the amine curing agent includes at least one of dicyandiamide, 4,4'-diaminodiphenylmethane and meta-phenylenediamine, preferably dicyandiamide.

[0050] In a specific embodiment of the present invention, the acid anhydride curing agent includes at least one of methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride, preferably methylhexahydrophthalic anhydride.

[0051] For example, in different embodiments, the amount of the second curing agent is 0.5 to 1.5 parts, specifically 0.5 parts, 0.7 parts, 0.9 parts, 1.1 parts, 1.3 parts, 1.5 parts or any value between any two ends thereof.

[0052] In a specific embodiment of the present invention, the amount of the amine curing agent is 0.4 to 1 part, specifically 0.4 part, 0.6 part, 0.8 part, 1 part or any value between the two end values; the amount of the acid anhydride curing agent is 0.1 to 0.5 part, specifically 0.1 part, 0.3 part, 0.5 part or any value between the two end values; the amount of the amine curing agent is more than the amount of the acid anhydride curing agent. The reason why the amount of the amine curing agent is more than the amount of the acid anhydride curing agent in the present invention is to ensure that the amine curing agent can react with the epoxy resin, thereby improving the hardness and shear strength of the adhesive, and ensuring rapid curing after thermal activation.

[0053] In the present invention, there is no restriction on the preparation method of the fast-curing adhesive, and a conventional adhesive preparation method can be adopted. The present invention provides an adhesive preparation method, comprising the following steps: mixing the components in proportion, stirring evenly and then standing to defoam.

[0054] In a specific embodiment of the present invention, the preparation method further comprises: uniformly mixing the dilution solvent with each component until the solid content is 35% to 45%. Furthermore, the dilution solvent includes but is not limited to ethyl acetate.

[0055] 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.

[0056] The second aspect of the present invention provides an adhesive product, comprising a support layer and an adhesive layer disposed on at least one side of the support layer; the adhesive layer is mainly made of the fast-curable adhesive composition described in the first aspect of the present invention.

[0057] In a specific embodiment of the present invention, the thickness of the adhesive layer is 50-100 μm, for example, 50 μm, 60 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 thick, it is difficult to fully solidify during hot pressing, and the bonding performance does not meet the requirements; if the thickness is too thin, the bonding strength of the adhesive will decrease.

[0058] In a specific embodiment of the present invention, the support layer may be a substrate, a release film or other structure that can support the adhesive layer. The release film may be a non-silicon release film. There is no specific limitation on the thickness of the support layer, and different thicknesses may be selected according to actual use requirements.

[0059] The present invention also provides an optional method for preparing the above-mentioned adhesive product, comprising the following steps: coating the adhesive composed of the composition on the surface of the release film, and drying the composition to obtain the adhesive product.

[0060] The coating method is not limited, and roller coating, blade coating or dip coating can be used. The thickness of the release film 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.

[0061] In a specific embodiment of the present invention, the drying process comprises: drying at 100-120° C. for 4-6 minutes.

[0062] In a specific embodiment of the present invention, a release film may be coated on the surface of the dried adhesive layer.

[0063] When the adhesive product of the present invention is actually used, the release film layers on both sides are torn off, the adhesive film is directly attached to the surface of the object to be bonded at room temperature, and then hot-pressed; wherein the hot-pressing process is: temperature 180-200°C, pressure 0.5Mpa-0.8Mpa, and hot-pressing time 5-30s.

[0064] In actual use, the adhesive product of the present invention can be used for bonding metal substrates such as aluminum (Al), but is not limited thereto. The thickness of the object to be bonded (such as a metal substrate) is generally not more than 1 cm. If the thickness of the bonded object is thicker, it will affect the thermosetting effect and further affect the bonding performance of the adhesive.

[0065] The following specific examples are given to further illustrate the purpose and advantages of the present invention, but these examples should not be considered as limiting the present invention. In the following examples, 1 g represents 1 part by weight.

[0066] Example 1

[0067] The fast curing adhesive provided in this embodiment includes the following components:

[0068] First Epoxy Resin: HM-091, 45g;

[0069] Second epoxy resin: CELLOXIDE 2021P, 25 g;

[0070] Isophthalic unsaturated polyester resin: A 400-901, 30g;

[0071] First curing agent: diallyl phthalate, 0.6g;

[0072] Second curing agent: 0.7 g of dicyandiamide and 0.3 g of methylhexahydrophthalic anhydride.

[0073] The preparation method of the adhesive is as follows: uniformly mix the above components in parts by weight, add a proper amount of ethyl acetate to dilute to a solid content of 40%, and obtain the adhesive to be coated.

[0074] Example 2

[0075] 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, as shown below; the types of the components and the preparation method of the adhesive are the same as those in Example 1.

[0076] The fast curing adhesive provided in this embodiment includes the following components:

[0077] HM-091, 50g;

[0078] CELLOXIDE 2021P, 30g;

[0079] A 400-901, 20g;

[0080] Diallyl phthalate, 0.2 g;

[0081] 0.4g dicyandiamide and 0.1g methylhexahydrophthalic anhydride.

[0082] Example 3

[0083] 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, as shown below; the types of the components and the preparation method of the adhesive are the same as those in Example 1.

[0084] The fast curing adhesive provided in this embodiment includes the following components:

[0085] HM-091, 40g;

[0086] CELLOXIDE 2021P, 20g;

[0087] A 400-901, 40g;

[0088] Diallyl phthalate, 1 g;

[0089] 1g dicyandiamide and 0.5g methylhexahydrophthalic anhydride.

[0090] Example 4 Group

[0091] This embodiment group is carried out with reference to the embodiment 1, except that: the first epoxy resin with different epoxy equivalent value is used in the adhesive, and the rest is the same as the embodiment 1, and the specific differences are as follows:

[0092] Example 4a: The first epoxy resin is KD-2159 produced by Guodu Chemical (Kunshan) Co., Ltd., and its epoxy equivalent is 2,450-2,850 g / eq;

[0093] Example 4b: The first epoxy resin is produced by DIC Corporation of Japan 4050, whose epoxy equivalent is 900 to 1,000 g / eq;

[0094] Example 4c: The first epoxy resin is produced by DIC Corporation of Japan HM-101, its epoxy equivalent is 3,200 to 3,900 g / eq.

[0095] Example 5 Group

[0096] This embodiment group is carried out with reference to the embodiment 1, except that the second epoxy resin in the adhesive is an alicyclic epoxy resin with a different epoxy equivalent value, and the rest is the same as the embodiment 1, and the specific differences are as follows:

[0097] Example 5a: The second epoxy resin is EHPE3150CE produced by Daicel (China) Investment Co., Ltd., and its epoxy equivalent is 150 g / eq;

[0098] Example 5b: The second epoxy resin is CELLOXIDE8010 produced by Daicel (China) Investment Co., Ltd., and its epoxy equivalent is 100 g / eq;

[0099] Example 5c: The second epoxy resin is EPOLEAD GT401 produced by Daicel (China) Investment Co., Ltd., and its epoxy equivalent is 220 g / eq.

[0100] Example 6 Group

[0101] This embodiment group was carried out with reference to embodiment 1, except that: different weights of the first epoxy resin and the second epoxy resin were used in the adhesive to verify the effect of the mass ratio of the first epoxy resin to the second epoxy resin on the product performance, and the rest was the same as embodiment 1, and the specific differences are as follows:

[0102] Example 6a: 40 g of the first epoxy resin and 30 g of the second epoxy resin, the mass ratio of the first epoxy resin to the second epoxy resin is 1.3:1;

[0103] Example 6b: 50 g of the first epoxy resin and 20 g of the second epoxy resin, the mass ratio of the first epoxy resin to the second epoxy resin is 2.5:1;

[0104] Example 6c: 35 g of the first epoxy resin and 35 g of the second epoxy resin, the mass ratio of the first epoxy resin to the second epoxy resin is 1:1;

[0105] Example 6d: 52 g of the first epoxy resin and 18 g of the second epoxy resin, the mass ratio of the first epoxy resin to the second epoxy resin is 2.9:1.

[0106] Comparative Example 1

[0107] This comparative example is carried out with reference to Example 1, except that: the adhesive does not contain the first epoxy resin; the types of other components and the preparation method of the adhesive are the same as those in Example 1.

[0108] Comparative Example 2

[0109] This group of comparative examples is carried out with reference to Example 1, except that the amount or type of the second epoxy resin in the adhesive is different, and the rest is the same as Example 1, and the specific differences are as follows:

[0110] Comparative Example 2a: This comparative example does not contain the second epoxy resin;

[0111] Comparative Example 2b: The second epoxy resin in this comparative example is a non-alicyclic bisphenol A epoxy resin, DER331 produced by Olin Corporation of the United States, and has an epoxy equivalent of 182-192 g / eq.

[0112] Comparative Example 3

[0113] This group of comparative examples is carried out with reference to Example 1, except that the type of isophthalic unsaturated polyester resin in the adhesive is different, and the rest is the same as Example 1, and the specific differences are as follows:

[0114] Comparative Example 3a: Using the product produced by Jinling Liliansi Resin Co., Ltd. A 400-972 (isophenyl unsaturated polyester resin), with an acid value of 8-14 mgKOH / g and a viscosity of 400-550 mPa.s at 23°C;

[0115] Comparative Example 3b: Using the product produced by Jinling Liliansi Resin Co., Ltd. P 65-972 (o-phthalic unsaturated polyester resin), the acid value of which is 20-26 mgKOH / g, and the viscosity at 23°C is 400-550 mPa.s.

[0116] Comparative Example 4

[0117] This comparative example group was carried out with reference to Example 1, except that: different weights of the first curing agent were added to the adhesive to verify the effect of the amount of the first curing agent added on the initial adhesion of the adhesive, and the rest was the same as Example 1, with the specific differences as follows:

[0118] Comparative Example 4a: 0.1 g of diallyl phthalate;

[0119] Comparative Example 4b: 1.1 g of diallyl phthalate.

[0120] Test Case

[0121] The adhesives prepared in the above embodiments and comparative examples were coated on the surface of a 50 μm thick non-silicone release film by blade coating, and baked in an oven at 110°C for 5 min to obtain a 50 μm thick adhesive film, which was then laminated with a 50 μm thick release film to obtain an adhesive product; a 2 cm × 3 cm sample of the obtained adhesive product was taken, the release films on both sides were torn off, and the product was laminated between two aluminum plate substrates (the thickness of a single-layer aluminum plate substrate is 3 mm) at room temperature (25°C), and then hot-pressed at 180°C and 0.5 MPa for 20 s, and then cooled to room temperature (25°C) for the following tests. The test results are shown in Table 1.

[0122] Shear strength: The samples after hot pressing and curing are tested for shear strength according to the national standard GB / T 33332-2016 "Test method for dynamic shear strength of adhesive tapes". The shear strength of the adhesive can characterize the bonding strength. In order to meet the requirements of product use, the shear strength generally needs to be no less than 25MPa.

[0123] Impact strength: The impact strength of the hot-pressed cured samples is 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 generally needs to be no less than 2.0J;

[0124] Initial adhesion: Test the initial adhesion of adhesive products that have not been subjected to heat pressing treatment in accordance with the national standard GB / T 4852-2002 "Test method for initial adhesion of pressure-sensitive adhesive tapes (rolling ball method)", and record the corresponding ball number. If the ball number is between 7 and 20, it means that the initial adhesion can meet the product use requirements; if the ball number is lower than 7, the initial adhesion is low and does not meet the pre-lamination positioning requirements; if the ball number is higher than 20, it means that the initial adhesion is too strong and it is not convenient to reposition during pre-lamination.

[0125] Table 1 Performance test results of different embodiments and comparative examples

[0126]

[0127]

[0128] It can be seen from the above test results that the adhesive product prepared by the adhesive composition of the present invention not only has suitable initial adhesion and can meet the effect of room temperature bonding and positioning; it can also achieve rapid hot pressing curing, and the cured adhesive has excellent shear strength (shear strength ≥ 27MPa) and impact strength (impact strength ≥ 2.4J).

[0129] It can be seen from the test results of Example 4 and Example 5 that when the epoxy equivalents of the first epoxy resin and the second epoxy resin are within the range specified in the present invention, the adhesive has good shear properties and impact strength after curing.

[0130] It can be seen from the test results of Example 6 that when the mass ratio of the first epoxy resin to the second epoxy resin is within the specified range of the present invention, the initial adhesion, shear properties after curing and impact strength of the adhesive can be significantly improved; it also shows that when the amount of the first epoxy resin or the second epoxy resin exceeds the specified range of the present invention, its various properties will also decrease.

[0131] It can be seen from the test results of comparative example 1 that when the first epoxy resin is not introduced into the adhesive, the adhesive product is unevenly cured and the cross-linking site is unstable due to the too fast curing reaction, and the shear performance and impact resistance of the cured adhesive drop sharply, and it is impossible to achieve product bonding; it can be seen from the test results of comparative example 2 that when the second epoxy resin is not introduced into the adhesive, the adhesive product is not completely cured by heat activation in a short time, so that the hardness of the cured product decreases, resulting in a sharp drop in its shear performance and impact resistance after curing, and it is impossible to achieve product bonding; when non-alicyclic epoxy resin is used in the adhesive, it cannot be bonded with anhydride solid in a short time. The first curing agent is used for rapid heat activation curing, resulting in a decrease in its performance. The test results of comparative example 3 show that when the acid value and viscosity of the isophthalic unsaturated polyester resin are lower than the specified range, the first curing agent cannot react completely with the unsaturated polyester resin, and the initial viscosity of the adhesive increases sharply, while the resin with a low acid value will not react completely during B-stage curing, resulting in a decrease in the performance of the adhesive after curing. When an orthophthalic unsaturated polyester resin is used, due to its strong rigidity, the adhesive is more brittle, and the impact resistance will decrease after hot pressing curing. The test results of comparative example 4 show that when the content of the first curing agent exceeds the specified range, the initial viscosity of the film will be affected.

[0132] 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. A fast curable adhesive composition, characterized in that: It includes the following components by weight: Wherein, the total weight of the first epoxy resin, the second epoxy resin and the isophthalic unsaturated polyester resin is 100 parts; The epoxy equivalent of the first epoxy resin is 2,000 to 3,000 g / eq; the second epoxy resin is an alicyclic epoxy resin; The first curing agent contains a reactive double bond, and the second curing agent includes an amine curing agent and an acid anhydride curing agent.

2. The fast curable adhesive composition according to claim 1, characterized in that: The epoxy equivalent of the second epoxy resin is 120 to 200 g / eq.

3. The fast curable adhesive composition according to claim 1, characterized in that: The acid value of the isophthalic unsaturated polyester resin is 15 to 20 mgKOH / g; And / or, the viscosity of the isophthalic unsaturated polyester resin is 850 to 1,200 mPa.s.

4. The fast curable adhesive composition according to claim 1 or 2, characterized in that: The mass ratio of the first epoxy resin to the second epoxy resin is (1.3-2.5):

1.

5. The fast curable adhesive composition according to claim 1, characterized in that: The amount of the amine curing agent used is greater than that of the anhydride curing agent used.

6. The fast curable adhesive composition according to claim 1 or 5, characterized in that: The amine curing agent includes at least one of dicyandiamide, 4,4'-diaminodiphenylmethane and m-phenylenediamine; And / or, the anhydride curing agent includes at least one of methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride.

7. The fast curable adhesive composition according to claim 1, characterized in that: The first curing agent includes at least one of (meth)acrylate, maleate, fumarate, itaconate, allyl ester and diallyl phthalate.

8. The fast curable adhesive composition according to claim 4, characterized in that: The first epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, polyurethane modified epoxy resin and glycidyl ester epoxy resin.

9. An adhesive product, characterized in that: It comprises a support layer and an adhesive layer arranged on at least one side of the support layer; the adhesive layer is mainly made of the fast-curing 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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