Technical Field

The present application relates to the technical field of adhesives, in particular to the technical field of adhesives for consumer electronic products and automobile parts. Specifically, the present application provides a two-component adhesive composition, in particular a two-component adhesive composition for bonding polybutylene terephthalate (PBT) composite materials.

Background

In the current manufacturing process of various consumer electronic products (such as mobile phones, tablet computers, laptops, and wearable electronic products) and automobile parts, two-component adhesives are usually used to achieve rapid bonding between different component surfaces. With the development of technology, more and more plastic composite materials (such as polybutylene terephthalate composite materials) are used in these consumer electronic products and automobile parts. However, these plastic composite materials, especially glass fiber reinforced or inorganic filler modified polybutylene terephthalate composite materials, are usually difficult to be effectively bonded by using conventional two-component adhesives.

Therefore, it is of great significance to develop a two-component adhesive with good bonding performance to plastic composite materials (especially polybutylene terephthalate composite materials).

Summary

Starting from the technical problem described above, the purpose of the present application is to provide a two-component adhesive composition, which has good bonding performance to plastic composite materials (especially polybutylene terephthalate composite materials) and metal materials (especially aluminum materials).

The inventors have conducted intensive and detailed research to achieve the present invention.

According to one aspect of the present application, the present application provides a two- component adhesive composition, comprising:

1.5-18 parts by weight of an epoxy resin; an effective amount of a peroxide oxidant; an effective amount of a reducing agent;

22-37 parts by weight of methyl methacrylate;

4-15 parts by weight of tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate; and

8-19 parts by weight of a free radical reactive acrylate oligomer; wherein the two-component adhesive composition comprises a part A and a part B, the part A comprises the peroxide oxidant, the part B comprises the reducing agent, and the epoxy resin, methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the free radical reactive acrylate oligomer exist in one or two of the part A and the part B.

According to another aspect of the present application, the present application provides an adhesive for bonding polybutylene terephthalate composite materials, comprising the two- component adhesive composition described above.

Compared with the existing techniques in the art, the present invention has the following advantages: The two-component adhesive composition in the technical solution provided by the present application has good bonding performance to plastic composite materials (especially polybutylene terephthalate composite materials) and metal materials (especially aluminum materials).

Detailed Description

It is to be understood that a person skilled in the art can envisage other various embodiments according to teachings in this description, and can make modifications thereto without departing from the scope or spirit of the present disclosure. Therefore, the following particular embodiments are not restrictive in meaning.

All figures for denoting characteristic dimensions, quantities and physicochemical properties used in this description and claims are to be understood as modified by a term "about" in all situations, unless indicated otherwise. Therefore, unless stated conversely, parameters in numerical values listed in the above description and the claims are all approximate values, and a person skilled in the art is capable of seeking to obtain desired properties by taking advantage of contents of the teachings disclosed herein, and changing these approximate values appropriately. The use of a numerical range represented by end points includes all figures within the range and any range within the range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.

As found by the inventor, when a specific amount of combination of the epoxy resin, the peroxide oxidant, the reducing agent, methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the free radical reactive acrylate oligomer is used, a two-component adhesive composition with good bonding performance to polybutylene terephthalate composite materials and metal materials (especially aluminum) can be prepared.

According to the technical solution of the present application, the two-component adhesive composition comprises an epoxy resin as a necessary component. Under the action of the redox reaction of an oxidant and a reducing agent, cross-linking reaction of the epoxy resin and methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the free radical reactive acrylate oligomer described in detail below, so as to realize the bonding effect. According to some preferred technical solutions of the present application, in order to facilitate the preparation and preservation of the two-component adhesive composition, preferably, the part A comprises the epoxy resin and the peroxide oxidant, and the part B comprises the reducing agent, methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the free radical reactive acrylate oligomer.

A specific type of the epoxy resin which can be used in the present application is not particularly limited. The term "epoxy resin" according to the present invention has the general meaning generally recognized about epoxy resins in the art, and epoxy resin refers to an organic epoxy compound containing two or more epoxy groups in the molecule. Any organic compound having an oxirane ring polymerizable by ring-opening reaction can be used as the epoxy resin employed in the technical solution according to the present application, as long as the epoxy resin is in a liquid state at room temperature and has a viscosity ranging from 200-35000 centipoises at 25°C measured by a rotary viscometer (e.g., Brookfield rotary viscometer). Preferably, the epoxy resin is one or more selected from an aliphatic epoxy resin, an alicyclic epoxy resin, an aromatic epoxy resin, and a heterocyclic epoxy resin. In the present invention, an organic epoxy compound comprising 2- 4 epoxy groups in the molecule is preferably used. In order to meet the above requirements regarding the liquid form and viscosity range, preferably, the epoxy equivalent of the liquid epoxy resin is in the range of 100-500, and preferably 150-300. Specifically, the liquid epoxy resin is one or more selected from the group consisting of: alkylene oxide, alkenyl oxide, glycidyl ester, glycidyl ether, epoxy novolac, glycidyl acrylate, and polyurethane polyepoxide and the like. More preferred epoxy resins include epoxy resins containing glycidyl ether or polyglycidyl ethers of monohydric, dihydric or polyhydric phenol, or epoxy resins composed of glycidyl ether or polyglycidyl ethers of monohydric, dihydric or polyhydric phenol. The monohydric, dihydric or polyhydric phenol is, for example, but not limited to bisphenol A, bisphenol F, and polymers including repeating units comprising these phenols. Preferably, the epoxy resin is one or more selected from a bisphenol A epoxy resin, a bisphenol F epoxy resin, a bisphenol S epoxy resin, and a novolac epoxy resin. Examples of the commercially available epoxy resin that can be used in the present application include bisphenol A diglycidyl ether, e.g., D.E.R-331 (liquid; epoxy equivalent: 182-192; viscosity at 25°C: 11000-14000 centipoises) and D.E.R-332 (liquid; epoxy equivalent: 171-175; viscosity at 25°C: 4000-6000 centipoises) available from Olin Company, USA, and EPON828 (liquid; epoxy equivalent: 185-192; viscosity at 25°C: 11000-15000 centipoises), EPON830 (liquid; epoxy equivalent: 190-198; viscosity at 25°C: 17000-22500 centipoises) and EPON1001F (liquid; epoxy equivalent: 525-550; viscosity at 25°C: 7000-9600 centipoises) available from Hexion Speciality Chemicals GmbH, Rosbach, Germany; bisphenol F diglycidyl ether, e.g., EPICLON 830 (liquid; epoxy equivalent: 165-180; viscosity at 25°C: 3000-4000 centipoises) available from Dainippon Ink and Chemicals, Inc., and D.E.R.-354 (liquid; epoxy equivalent: 167-174; viscosity at 25°C: 3400- 4200 centipoises) available from Olin Company, USA; and other epoxy resins based on bisphenol;. e.g., EPIKOTE828 (liquid; epoxy equivalent: 184-190; viscosity at25°C: 12000-14000 centipoises) available from Hexion Speciality Chemicals, Rosbach, Germany, and EPILOX A 18-00 (liquid; epoxy equivalent: 175-185; viscosity at25°C: 8000-10000 centipoises) available from LeunaEpilox GmbH, Leuna, Germany. According to the technical solution of the present application, the two- component adhesive composition comprises 1.5-18 parts by weight and preferably 2-18 parts by weight of an epoxy resin.

The two-component adhesive composition according to the present invention comprises a peroxide oxidant. During use, free radicals are generated by the redox reaction between the peroxide oxidant and the reducing agent, and the free radicals initiate the cross-linking reaction of the combination of methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the free radical reactive acrylate oligomer described in detail below, so as to promote the curing of the two-component adhesive composition. The particular type of the peroxide oxidant that can be used in the present invention is not particularly limited, and the peroxide oxidant may be selected from the oxidants commonly used for crosslinking acrylate monomers in the art. Preferably, the peroxide oxidant is one or more peroxide oxidants selected from the group consisting of hydroperoxide oxidants, ketone peroxide oxidants, and diacyl peroxide oxidants. Particularly, the hydroperoxide oxidant includes: tert-butyl hydroperoxide, cumene hydroperoxide, isopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydrogenperoxide and 1, 1,3,3- tetramethylbutyl hydroperoxide, and the like. Particularly, the ketone oxidant includes: methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethyl cyclohexanone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, and the like. The diacyl peroxide oxidant includes: benzoyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, succinic peroxide, benzoyl peroxide (for example, dibenzoyl peroxide), 2,4-dichlorobenzoyl peroxide, m-toluoyl peroxide, and the like. One or more of these peroxides may be used. Those skilled in the art may select a reducing agent matched with the oxidant according to the selected oxidant. According to the technical solution of the present application, the two-component adhesive composition comprises 1.5-9 parts by weight and preferably 1.8-6 parts by weight of a peroxide oxidant. If the amount of the peroxide oxidant in the two-component adhesive composition is less than 1.5 parts by weight, the adhesive will undercure and not have sufficient adhesion during use. If the amount of the peroxide oxidant in the two-component adhesive composition is greater than 9 parts by weight, the cured product will have decreased adhesion and reduced stability.

In order to promote the effective decomposition of the peroxide oxidant to accelerate cross- linking and curing of the combination of methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the free radical reactive acrylate oligomer, the two- component adhesive composition according to the present application further comprises at least one reducing agent. The reducing agent is one or more selected from a tertiary amine reducing agent, an organic acid metal salt reducing agent, an organic metal chelate reducing agent, and a thiourea reducing agent. Preferably, when a hydroperoxide oxidant or a ketone peroxide oxidant is employed as the peroxide oxidant, the reducing agent is one or more selected from an organic acid metal salt reducing agent, an organic metal chelate reducing agent, and a thiourea reducing agent. Specifically, the organic acid metal salt reducing agent and the organic metal chelate reducing agent include: cobalt naphthenate, copper naphthenate, manganese naphthenate, cobalt octoate, copper octoate, manganese octoate, copper acetylacetonate, titanium acetylacetonate, manganese acetylacetonate, chromium acetylacetonate, iron acetylacetonate, vanadium acetylacetonate, cobalt acetylacetonate, and the like. In addition, when the diacyl peroxide oxidant is used as the peroxide oxidant, the tertiary amine reducing agent, such as N,N-dimethyl-p-toluidine, N,N-diethyl-p-toluidine, N,N-di(2- hydroxyethyl)-p-toluidine, N,N-diisopropanol-p-toluidine, triethylamine, tripropylamine, ethyl diethanolamine, N,N-dimethylaniline, ethylene diamine, triethanolamine, aldehyde-amine condensation reactants, and the like, may be used. One, two or more of these reducing agents may be used. According to the technical solution of the present application, the two-component adhesive composition comprises 0.4-3 parts by weight of a reducing agent. If the amount of the reducing agent in the two-component adhesive composition is less than 0.4 parts by weight, the adhesive will undercure and not have sufficient adhesion during use. If the amount of the reducing agent in the two-component adhesive composition is greater than 3 parts by weight, the cured product will have decreased adhesion and reduced stability.

According to the technical solution of present application, in order to avoid premature curing of the two-component adhesive composition, the peroxide oxidant exists in the part A, and the reducing agent exists in the part B. Preferably, the part A and the part B are contained in the two- component adhesive composition as two separate parts.

According to some specific examples of the present application, the combination of methyl methacrylate (MMA) and tetrahydrofiirfuryl acrylate and/or propoxylated tetrahydrofiirfuryl acrylate and the free radical reactive acrylate oligomer is employed as the basic material for the two- component adhesive composition. The acrylic resin adhesive prepared from the combination of methyl methacrylate (MMA) and the tetrahydrofiirfuryl acrylate and/or propoxylated tetrahydrofiirfuryl acrylate and the free radical reactive acrylate oligomer has good durability and environmental friendliness, and is conducive to achieve good bonding performance to polybutylene terephthalate composite materials and metal materials (especially aluminum). The combination of methyl methacrylate (MMA) and tetrahydrofiirfuryl acrylate and/or propoxylated tetrahydrofiirfuryl acrylate and the free radical reactive acrylate oligomer may optionally exist in one or two of the part A and the part B. The specific sources of the methyl methacrylate (MMA) and the tetrahydrofiirfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate that can be used in the present application are not specially limited, and they may be used directly without being further purified. The specific examples of the free radical reactive acrylate oligomer that can be used in the present application are not specially limited. According to the technical solution of the present application, the two- component adhesive composition comprises 22-37 parts by weight of methyl methacrylate. According to the technical solution of the present application, the amount of the methyl methacrylate (MMA) in the two-component adhesive composition is from as equal to or greater than 22 parts by weight, equal to or greater than 24 parts by weight, equal to or greater than 30 parts by weight and equal to or less than 37 parts by weight, or equal to or less than 36 parts by weight, or equal to or less than 35 parts by weight. As the major monomer in the composition, MMA provide good swelling effect on the surface of plastic material. According to the technical solution of the present application, the two-component adhesive composition comprises 4-15 parts by weight of tetrahydrofurfuryl acrylate, propoxylated tetrahydrofurfuryl acrylate, or a mixture of tetrahydrofurfuryl acrylate and propoxylated tetrahydrofurfuryl acrylate. According to the technical solution of the present application, the two-component adhesive composition comprises 8-19 parts by weight of a free radical reactive acrylate oligomer. Preferably, the free radical reactive acrylate oligomer is an aliphatic polyurethane acrylate oligomer. Preferably, the number average molecular weight of the aliphatic polyurethane acrylate oligomer is in a range of 3000 g/mol to 8000 g/mol. According to the technical solution of the present application, the amount of the tetrahydrofurfuryl acrylate, propoxylated tetrahydrofurfuryl acrylate, or a mixture of tetrahydrofurfuryl acrylate and propoxylated tetrahydrofurfuryl acrylate in the two-component adhesive composition is from as equal to or greater than 8 parts by weight, equal to or greater than 9 parts by weight, equal to or greater than 10 parts by weight and equal to or less than 19 parts by weight, or equal to or less than 17 parts by weight.

According to the technical solution of the present application, in order to further improve the bonding performance of the two-component adhesive composition to polybutylene terephthalate composite materials and metal materials (especially aluminum), preferably, the two-component adhesive composition further comprises 4-16 parts by weight or 4.5-15 parts by weight of an acrylate monomer with 6-26 carbon atoms. Preferably, the acrylate monomer with 6-26 carbon atoms is one or more selected from hydroxyethyl methacrylate and 3,3,5-trimethylcyclohexyl acrylate.

Preferably, the two-component adhesive composition further comprises less than or equal to 8 parts by weight of methacrylic acid monomer.

According to the technical solution of the present application, in order to give the two- component adhesive composition additional desired properties (e.g., thermal conductivity, color, curability, stability, mechanical strength, etc.), the two-component adhesive composition may further optionally comprise one or more additives. Preferably, the two-component adhesive composition further comprises less than or equal to 9 parts by weight of an inorganic filler. The inorganic filler is selected from the group consisting of aluminum hydroxide particles, silicon dioxide particles, calcium carbonate particles, aluminum oxide particles, and the like.

In order to give the adhesive product the desired color, the two-component adhesive composition further comprise less than 0.3 parts by weight of a pigment. The pigment is preferably an inorganic pigment (for example, carbon black).

In addition, in order to adjust the curing speed of the two-component adhesive composition to provide appropriate operable time, preferably, the two-component adhesive composition further comprises less than 1.5 parts by weight of an epoxy hardener. Preferably, the epoxy hardener is an amine epoxy hardener. Commercially available examples of the amine epoxy hardener that can be used in the present application include DEH622 produced by Olin, USA.

In addition, in order to improve the stability of the two-component adhesive composition after preparation, preferably, the two-component adhesive composition further comprises less than 0.5 parts by weight of a system stabilizer. The system stabilizer may be one or more selected from thiourea, hydroquinone, methoxyphenol and 2,6-di-tert-butyl-4-methylphenol.

In order to improve the bonding performance of the two-component adhesive composition to a substrate to be bonded (for example, a polybutylene terephthalate composite component in a consumer electronic product), preferably, the two-component adhesive composition further comprises less than 8 parts by weight of a tackifier, or comprises less than 7.5 parts by weight of a tackifier, or comprises less than 5 parts by weight of a tackifier. The adhesion promoter comprises an acrylic copolymer tackifier. Specific commercially available examples of the tackifier that can be used in the present application include acResin DS 3532 (acrylic copolymer) produced by BASF (China), which does not participate in free radical polymerization and unexpectedly has a good bonding effect on the surface of PBT. If the addition amount is excessive, the bonding strength of the adhesive composition will be reduced.

In order to improve the bonding performance of the two-component adhesive composition to a substrate to be bonded (for example, a metal material component in a consumer electronic product), preferably, the two-component adhesive composition further comprises less than 2 parts by weight of an adhesion promoter, or comprises less than .5 parts by weight of an adhesion promoter, or comprises less than 1 part of an adhesion promoter. The adhesion promoter may be an acrylate phosphate adhesion promoter commonly used in the art. Specific commercially available examples of the adhesion promoter that can be used in the present application include P-2M (2- hydroxyethyl methacrylate phosphate) produced by KYOEISHA CHEMICAL.

In addition, in order to improve the physical and mechanical properties of the adhesive formed by the two-component adhesive composition, preferably, the two-component adhesive composition further comprises less than 25 parts by weight or less than or equal to 21 parts by weight of an impact resistant agent. Specific commercially available examples of the impact resistant agent that can be used in the present application include MBS (methacrylate-butadiene-styrene) core-shell copolymer impact resistant agent produced by Dow Company, USA, with an average particle size of 100-400 pm, and NBR (acrylonitrile-butadiene rubber) impact resistant agent produced by ARLANXEO High Performance, with an average particle size of 500-900 pm.

According to some preferred examples of the present application, in order to promote the efficiency of mixing the part A and the part B in use to improve its applicability, preferably, the epoxy resin and peroxide oxidant exist in the part A, and the reducing agent, methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the acrylate oligomer exist in the part B. Preferably, the mass ratio of the part A to the part B is in a range of 1:10-10: 1, and preferably 1:10-1:2. Most preferably, the mass ratio of the part A to the part B is 1: 10.

According to another aspect of the present application, the present application provides an adhesive for bonding polybutylene terephthalate composite materials, comprising the two- component adhesive composition described above.

The method for preparing the two-component adhesive composition is not particularly limited, which may be prepared by simple mixing. Specifically, the two-component adhesive composition obtained by mixing comprises a part A and a part B, the part A comprises the peroxide oxidant, the part B comprises the reducing agent, and the epoxy resin, methyl methacrylate, tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate and the acrylate oligomer exist in one or two of the part A and the part B.

The present invention will be described below in more details in combination with embodiments. It needs to be pointed out that these descriptions and embodiments are all intended to make the invention easy to understand, rather than to limit the invention. The protection scope of the present invention is subject to the appended claims.

Embodiments

In the present invention, unless otherwise pointed out, the reagents employed are all commercially available products, which are directly used without further purification. able 1. List of raw materials

Test method Bonding strength

The cured products obtained after curing of the two-component adhesive compositions obtained in the following examples and comparative examples were tested for the property of shear strength according to the following method, so as to evaluate the bonding performance thereof.

Separately, the part A and part B of the two-component adhesive compositions prepared in the following examples and comparative examples were uniformly mixed to obtain adhesives. Two PBT composite plates (70% PBT and 30% glass fiber composite) with a size of 101.6 mm (length) by 25.4 mm (width) by 2 mm (thickness) produced by Dongguan Baiside Plastic Co., Ltd. were taken, and the surfaces were wiped clean with isopropanol and air-dried at room temperature. The two PBT composite plates were overlapped in an overlaying mode of 25.4 mm (width) by 12.7 mm (length) from respective ends, where 0.1 g of uniformly distributed adhesive was clamped between the overlapping areas of the two PBT composite plates. Then, the PBT composite plates overlapped to the adhesive mixture were kept at room temperature for 24h. The shear strength (in MPa) was tested at room temperature (22-24°C) at a crosshead pulling speed of 2.54 mm/min according to the dynamic shear test standard ASTM D1002-72 with the Instron 5969 device produced by Instron Inc., USA. According to the test results of the bonding performance of the PBT composite plates, if the shear strength obtained was greater than or equal to 3.5 MPa, it was considered that the two- component adhesive composition had acceptable bonding performance to polybutylene terephthalate composite materials. If the shear strength obtained was greater than or equal to 4.0 MPa, it was considered that the two-component adhesive composition had good bonding performance to polybutylene terephthalate composite materials. If the shear strength obtained was greater than or equal to 5.0 MPa, it was considered that the two-component adhesive composition had excellent bonding performance to polybutylene terephthalate composite materials.

In addition, the part A and part B of the two-component adhesive compositions prepared in the following examples and comparative examples were uniformly mixed to obtain adhesives. Two aluminum plates (A1 6063 plates) with a size of 101.6 mm (length) by 25.4 mm (width) by 4mm (thickness) produced by Jiangsu Kunshan Great Wall Printing Factory, and the surfaces were wiped clean with isopropanol and air-dried at room temperature. The two A1 6063 plates were overlapped in an overlaying mode of 25.4 mm (width) by 12.7 mm (length) from respective ends, where 0.1 g of uniformly distributed adhesive was clamped between the overlapping areas of the two A1 6063 plates. Then, the A1 6063 plates overlapped to the adhesive mixture were kept at room temperature for 24h. The shear strength (in MPa) was tested at room temperature (22-24°C) at a crosshead pulling speed of 2.54 mm/min according to the dynamic shear test standard ASTM D1002-72 with the Instron 5969 device produced by Instron Inc., USA. According to the test results of the bonding performance to the aluminum plates (A1 6063), if the shear strength obtained was greater than or equal to 10 MPa, it was considered that the two-component adhesive composition had acceptable bonding performance to the aluminum plates (A1 6063). If the shear strength obtained was greater than or equal to 15 MPa, it was considered that the two-component adhesive composition had good bonding performance to the aluminum plates (A1 6063).

Example 1 (El)

A two-component adhesive composition 1 was prepared in example 1. The two-component adhesive composition 1 included a part A and a part B that were independent of each other. The preparation of the part A included uniformly mixing 1.95g of epoxy resin (D.E.R-331), 0.09g of blue pigment dispersion BlueJS652032, 0.14g of inorganic fdler fumed silica R202, 3.73g of inorganic fdler aluminum hydroxide MoldX A110 and 3.18g of peroxide oxidant (BM-50R) according to the ratio shown in Table 2 below. The preparation of the part B included uniformly mixing 0.98g of reducing agent (N,N-di(2-hydroxyethyl)-p-toluidine), 34.40g of methyl methacrylate (MMA), 4.9 lg of 3,3,5 -trimethylcyclohexyl acrylate (SR420), 1.97g of hydroxyethyl methacrylate (HEMA), 14.74g of tetrahydrofurfuryl acrylate (SR285), 9.83g of acrylate oligomer (CN8888), 0.49g of epoxy hardener (DEH622), 6.88g of impact resistant agent NBR (acrylonitrile - butadiene rubber) Baymod34.52, 0.98g of adhesion promoter (P-2M), 4.9 lg oftackifier acResin DS 3532, 7.86g of impact resistant agent MBS (methacrylate-butadiene-styrene) core-shell copolymer impact resistant agent (PARALOID EXL 2691 A) and 2.96g of inorganic fdler fumed silica R202, according to the ratio in Table 2 shown below.

The two-component adhesive composition 1 obtained according to the above steps was tested, according to the methods described in detail above regarding the bonding strength test. The test results obtained were shown in Table 2.

Examples 2-21 (E2-E21) and comparative examples 1-7 (CE1-CE7)

Two-component adhesive compositions 2-21 and comparative two-component adhesive compositions 1-7 were prepared respectively in a manner similar to example 1, according to the ratio in Table 2 or 3 shown below.

The two-component adhesive compositions 2-21 and comparative two-component adhesive compositions 1-7 obtained according to the above steps were tested, according to the methods described in detail above regarding the bonding strength test. The test results obtained were shown in Table 2 or Table 3. Table 2. Component ratio and performance test of two-component adhesive compositions 1-21

Table 3. Component ratio and performance test of comparative two-component adhesive compositions 1-7

From the results shown in Table 2 above, it can be seen that, when each component of the two-component adhesive composition and its specific content are selected in the range of the present application, the obtained two-component adhesive composition has good bonding performance to polybutylene terephthalate composite materials (70% PBT and 30% glass fiber composite plates) and metal plates (A1 6063 plates) (the bonding strength to 70% PBT and 30% glass fiber composite composite plates is greater than 3.5 MPa, and the bonding strength to A1 6063 plates is greater than 10 MPa).

In addition, it can be seen from the examples that, when the two-component adhesive composition comprises the specific amount (less than or equal to 8 parts by weight) of methacrylic acid (MAA) and the specific amount (4-16 parts by weight) of hydroxy ethyl methacrylate (HEMA) or 3,3,5-trimethylcyclohexyl acrylate (SR420), the bonding performance to polybutylene terephthalate composite materials can be further improved.

From the results of comparative example 1 (CE1) and comparative example 2 (CE2) in Table 3, it can be seen that, when the content of the methyl methacrylate (MMA) in the two- component adhesive compositions is not within the range of the present application, the bonding performance of the obtained adhesive to polybutylene terephthalate composite materials (70% PBT and 30% glass fiber composite plates) is poor (the bonding strength is respectively 2.6 MPa and 3.1 MPa), which does not meet the technical requirements on the bonding of polybutylene terephthalate composite parts in consumer electronic products.

From the results of comparative example 3 (CE3) and comparative example 4 (CE4) in Table 3, it can be seen that, when the content of the tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate in the two-component adhesive compositions is too low (i.e., 3.18 parts by weight) or too high (i.e., 15.91 parts by weight), the bonding performance of the obtained adhesive to polybutylene terephthalate composite materials (70% PBT and 30% glass fiber composite plates) is poor (the bonding strength is respectively 2.4 MPa and 2.1 MPa), which does not meet the technical requirements on the bonding of polybutylene terephthalate composite parts in consumer electronic products.

From the results of comparative example 5 (CE5) in Table 3, it can be seen that, when the content of the acrylate oligomer (CN8888) in the two-component adhesive composition is too low (i.e., 7.40 parts by weight), the bonding performance of the obtained adhesive to polybutylene terephthalate composite materials (70% PBT and 30% glass fiber composite plates) is poor (the bonding strength is 2.7 MPa), which does not meet the technical requirements on the bonding of polybutylene terephthalate composite parts in consumer electronic products.

From the results of comparative example 6 (CE6) in Table 3, it can be seen that, when the content of the acrylate oligomer (CN8888) in the two-component adhesive composition is too high (i.e., 19.89 parts by weight), the bonding performance of the obtained adhesive to polybutylene terephthalate composite materials (70% PBT and 30% glass fiber composite plates) is poor (the bonding strength is 1.9 MPa), which does not meet the technical requirements on the bonding of polybutylene terephthalate composite parts in consumer electronic products.

From the results of comparative example 7 (CE7) in Table 3, it can be seen that, when the tetrahydrofurfuryl acrylate and/or propoxylated tetrahydrofurfuryl acrylate in the two-component adhesive compositions is replaced with tetrahydrofurfuryl methacrylate with a very similar structure, surprisingly, the bonding performance of the obtained adhesive to polybutylene terephthalate composite materials (70% PBT and 30% glass fiber composite plates) is poor (the bonding strength is 2.5 MPa), which does not meet the technical requirements on the bonding of polybutylene terephthalate composite parts in consumer electronic products.

Although the above particular embodiments comprise many specific details for the purpose of illustration, those skilled in the art should understand that many variations, modifications, replacements and changes to these details all fall within the scope of the present invention as claimed in the claims. Therefore, the disclosure as described in the specific embodiments does not pose any limitation to the present invention as claimed in the claims . The proper scope of the present invention should be defined by the claims and proper legal equivalents thereof. All references referred to are incorporated herein by reference in their entireties.