UV-thermal dual-curing adhesive as well as preparation method and application thereof

Abstract

The invention provides a UV-thermal dual-curing adhesive and a preparation method and application thereof, and belongs to the technical field of adhesives, and the UV-thermal dual-curing adhesive is prepared from the following raw materials in parts by weight: 10-40 parts of silicon-free epoxy resin; 5 to 35 parts of epoxy silicone resin; 5-40 parts of a reactive diluent; 0.5 to 5 parts of a cationic photoinitiator; 0.1 to 3 parts of a cationic thermal initiator; 0.5 to 10 parts of a thixotropic agent; 0.1 to 2 parts of an antioxidant; and 30-60 parts of a filler. According to the UV-thermal dual-curing adhesive provided by the invention, the epoxy silicon resin is introduced on the basis that the system contains the silicon-free epoxy resin, and the two resins act together, so that the UV curing strength and the thermal curing strength can be adjusted, and the prepared UV-thermal dual-curing adhesive has high cohesiveness and high weather resistance at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of adhesives, and relates to a UV-heat dual-curing adhesive and a preparation method and application thereof, and specifically relates to a high-adhesion and high-weatherability UV-heat dual-curing adhesive and a preparation method and application thereof. Background Art

[0002] With the rapid advancement of smart hardware, such as the continuous upgrading of smart terminal products such as smartphones, electric vehicles, and PCs, the requirements for adhesives are becoming increasingly stringent. The traditional single curing method (such as UV light curing or thermal curing only) can no longer meet the rapid assembly and high-quality bonding requirements of these high-end products. Although UV light curing technology has the advantages of fast curing and high production efficiency, it has problems such as incomplete curing and the inability to cure irregular or special-shaped products; and although the adhesive using thermal curing has strong adhesion and good weather resistance, the thermal curing has a slow curing speed and high energy consumption. Therefore, a dual curing method combining UV light curing and thermal curing came into being to solve the shortcomings of a single curing method.

[0003] In the fields of high-end electronic products, automobile manufacturing, aerospace, etc., there are extremely high requirements for the bonding strength and weather resistance of adhesives. UV-heat dual-curing adhesives can achieve high bonding strength in a short time through a dual curing mechanism, and have excellent water resistance, high temperature resistance, aging resistance and other properties, thus being able to meet the strict requirements of adhesives in these fields.

[0004] Although UV-heat dual-curing adhesives combine the advantages of UV light curing and heat curing in many aspects, there are still some technical defects. UV-heat dual-curing adhesives need to meet both UV light irradiation and high temperature heating curing conditions. The UV light curing stage can usually achieve rapid curing, but the speed of the heat curing stage is relatively slow. This inconsistency in curing speed may lead to differences in the degree of curing in different areas of the product, thus affecting the overall performance of the product. UV-heat dual-curing adhesives may produce volume shrinkage during the curing process, especially in the UV light curing stage. This shrinkage not only affects the dimensional accuracy of the product, but also may cause stress concentration at the bonding interface, thereby reducing the bonding strength. In order to reduce the shrinkage rate, the formula needs to be precisely adjusted, but this often requires a trade-off between performance and cost. The heat curing stage can usually improve the heat resistance and weather resistance of the adhesive, but it may also bring other problems. For example, too high a curing temperature may cause some substrates to deform or damage, and also affect the appearance and performance of the product. Therefore, various factors need to be considered in the formulation design to ensure that the product has excellent heat resistance and weather resistance while not negatively affecting other properties. The formula design of UV-thermal dual-curing adhesives is relatively complex and requires consideration of the combined effects of multiple factors. For example, the selection and dosage of photoinitiators and thermal initiators, the type and properties of the resin matrix, the type and proportion of fillers and additives, etc., will have an important impact on the curing effect and performance of the product.

[0005] Therefore, it is desirable in the art to develop a UV-heat dual-curing adhesive having high adhesion and high weather resistance. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a UV-heat dual-curing adhesive and a preparation method and application thereof, and specifically to provide a high-adhesion, high-weather resistance UV-heat dual-curing adhesive and a preparation method and application thereof.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a UV-heat dual-curing adhesive, wherein the raw materials for preparing the UV-heat dual-curing adhesive include the following components in parts by weight:

[0009]

[0010]

[0011] The UV-heat dual-curing adhesive provided by the present invention introduces epoxy silicone resin on the basis of the system containing silicon-free epoxy resin. The two resins work together to adjust the UV curing and heat curing strengths, so that the prepared UV-heat dual-curing adhesive has high adhesion and high weather resistance.

[0012] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured in parts by weight, and the amount of the silicon-free epoxy resin can be 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, etc.

[0013] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured in parts by weight, and the amount of epoxy silicone resin used can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 35 parts, etc.

[0014] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured by weight, and the amount of the active diluent can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, etc.

[0015] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured in parts by weight, and the amount of the cationic photoinitiator used can be 0.5 parts, 0.6 parts, 0.8 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0016] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured by weight, and the amount of the cationic thermal initiator used can be 0.1 part, 0.3 part, 0.5 part, 0.6 part, 0.8 part, 1 part, 1.3 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2 parts, 2.3 parts, 2.5 parts, 2.6 parts, 2.8 parts, 3 parts, etc.

[0017] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured by weight, and the amount of the thixotropic agent used can be 0.5 parts, 0.6 parts, 0.8 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0018] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured by weight, and the amount of the antioxidant used can be 0.1 part, 0.3 part, 0.5 part, 0.6 part, 0.8 part, 1 part, 1.3 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2 parts, etc.

[0019] In the present invention, the raw materials for preparing the UV-heat dual-curing adhesive are measured by weight, and the amount of filler used can be 30 parts, 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, etc.

[0020] Preferably, the silicon-free epoxy resin includes any one of alicyclic epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, vinyl epoxy resin, hydrogenated bisphenol A epoxy resin or hydrogenated bisphenol F epoxy resin, or a combination of at least two thereof.

[0021] Preferably, the silicon-free epoxy resin includes any one or a combination of at least two of bis-(3,4-epoxycyclohexylmethyl) adipate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, di-4-epoxycyclohexane, 1,2:5,6-diepoxyhexahydroindane, 4-vinylepoxycyclohexane, 3,4-epoxycyclohexyl methacrylate, and 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester.

[0022] Preferably, the epoxy silicone resin includes any one of 1,1,3,3-tetramethyl-1,3-bis-[2-[7-oxidobicyclo[4.1.0]hept-3-yl]ethyl]disiloxane, tetraepoxycyclohexylethyl-2,4,6,8-tetramethylcyclotetrasiloxane, and 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, or a combination of at least two thereof.

[0023] Preferably, the active diluent includes any one of alkenyl ether active diluents, vinyl ketone acetal active diluents, epoxy active diluents, epoxidized triglyceride active diluents, oxetane active diluents, and mixed active diluents containing epoxy enol ether groups, or a combination of at least two thereof.

[0024] Preferably, the active diluent includes any one of 3-ethyl-3-oxetanemethanol, 3-ethyl-3-chloromethyloxetane, 3,3-[oxybismethylene]bis[3-ethyl]oxetane, 3-ethyl-3-[(2-ethyl)-hexyloxymethyl]oxetane, 3-ethyl-3-[(benzyloxy)methyl]oxetane, 3-ethyl-3-[(phenoxy)methyl]oxetane, and 3-ethyl-3-allylmethoxyoxetane, or a combination of at least two thereof.

[0025] Preferably, the cationic photoinitiator includes any one of aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, and aromatic ferrocenium salts, or a combination of at least two thereof.

[0026] Preferably, the cationic photoinitiator includes any one of diaryl pentafluorobenzene borate iodonium salt, diaryl hexafluorophosphate iodonium salt, diaryl hexafluoroantimonate iodonium salt, triaryl hexafluoroantimonate sulfonium salt, triaryl hexafluorophosphate sulfonium salt, ferrocenium hexafluorophosphate or a combination of at least two thereof.

[0027] Preferably, the cationic photoinitiator comprises diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate.

[0028] Preferably, the cationic thermal initiator includes any one of CXC1612, Vicbase TC3631, Vicbase TC3632, Vicbase TC3634, CTI-100, CTI-200 or CTI-300, or a combination of at least two thereof.

[0029] Preferably, the thixotropic agent comprises fumed silica and / or precipitated silica.

[0030] Preferably, the antioxidant comprises an aromatic amine antioxidant and / or a hindered phenol antioxidant.

[0031] Preferably, the aromatic amine antioxidant includes any one of diaryl secondary amines, p-phenylenediamine, ketoamines, and aldehyde amines, or a combination of at least two of them.

[0032] Preferably, the hindered phenol antioxidant includes any one of 2,6-di-tert-butyl-4-methylphenol, antioxidant AO-20, and antioxidant 1076, or a combination of at least two of them.

[0033] Preferably, the antioxidant is antioxidant AO-20.

[0034] Preferably, the filler comprises spherical silica powder and / or talc powder.

[0035] In a second aspect, the present invention provides a method for preparing the UV-heat dual-curing adhesive as described in the first aspect, the preparation method comprising the following steps:

[0036] The silicon-free epoxy resin, epoxy silicone resin, reactive diluent and cationic photoinitiator are mixed and heated until the cationic photoinitiator is dissolved, and then a thixotropic agent, a filler, an antioxidant and a cationic thermal initiator are added and mixed again to obtain the UV-heat dual-curing adhesive.

[0037] Preferably, the mixing is performed under yellow light conditions.

[0038] Preferably, the preparation method specifically comprises the following steps: mixing a silicon-free epoxy resin, an epoxy silicone resin, a reactive diluent, and a cationic photoinitiator under yellow light conditions, and heating until the cationic photoinitiator is dissolved, performing a first dispersion, and then adding a thixotropic agent, performing a second dispersion, and then adding a filler, performing a third dispersion, and then adding an antioxidant, performing a fourth dispersion, cooling, adding a cationic thermal initiator, performing a fifth dispersion, cooling, and then performing a sixth dispersion, filling with a rubber tube, and storing in a frozen state to obtain the UV-heat dual-curing adhesive.

[0039] Preferably, the rotation speed of the first dispersion is 1300-1700 rpm, for example, 1300 rpm, 1350 rpm, 1400 rpm, 1450 rpm, 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, etc., and the time is 1-3 min, for example, 1 min, 2 min, 3 min, etc.

[0040] Preferably, the rotation speed of the second dispersion is 1300-1700 rpm, for example, 1300 rpm, 1350 rpm, 1400 rpm, 1450 rpm, 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, etc., and the time is 1-3 min, for example, 1 min, 2 min, 3 min, etc.

[0041] Preferably, the rotation speed of the third dispersion is 1300-1700 rpm, for example, 1300 rpm, 1350 rpm, 1400 rpm, 1450 rpm, 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, etc., and the time is 4-6 min, for example, 4 min, 5 min, 6 min, etc.

[0042] Preferably, the fourth dispersion has a rotation speed of 1300-1700 rpm, for example, 1300 rpm, 1350 rpm, 1400 rpm, 1450 rpm, 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, etc., and a time of 1-3 min, for example, 1 min, 2 min, 3 min, etc.

[0043] Preferably, the rotation speed of the fifth dispersion is 1300-1700 rpm, for example, 1300 rpm, 1350 rpm, 1400 rpm, 1450 rpm, 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, etc., and the time is 1-3 min, for example, 1 min, 2 min, 3 min, etc.

[0044] Preferably, the fifth dispersion further includes a vacuum degassing step.

[0045] Preferably, the rotation speed of the sixth dispersion is 1300-1700rpm, for example, 1300rpm, 1350rpm, 1400rpm, 1450rpm, 1500rpm, 1550rpm, 1600rpm, 1650rpm, 1700rpm, etc., and the time is 1-3min, for example, 1min, 2min, 3min, etc.

[0046] Preferably, the sixth dispersion further includes a vacuum degassing step.

[0047] In a third aspect, the present invention provides an application of the UV-heat dual-curing adhesive as described in the first aspect in electronic products, automobile manufacturing, communications or aerospace.

[0048] Compared with the prior art, the present invention has at least the following beneficial effects:

[0049] The UV-heat dual-curing adhesive provided by the present invention introduces epoxy silicone resin on the basis of the system containing silicon-free epoxy resin. The two resins work together to adjust the UV curing and heat curing strengths, so that the prepared UV-heat dual-curing adhesive has high adhesion and high weather resistance. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0051] Examples 1-5

[0052] In Examples 1-5, a UV-heat dual-curing adhesive is provided respectively. The raw materials and amounts (parts by weight) of the UV-heat dual-curing adhesive are shown in Table 1.

[0053] Table 1

[0054]

[0055] The preparation method of UV-heat dual curing adhesive comprises the following steps:

[0056] Under yellow light conditions, a silicon-free epoxy resin, an epoxy silicone resin, an active diluent, and a cationic photoinitiator are mixed in a high-speed dispersion tank and heated until the cationic photoinitiator is dissolved, and then the high-speed dispersion tank is placed in a homogenizer and dispersed at 1500 rpm for 2 minutes, and then a thixotropic agent is added and stirred, and the mixture is placed in a homogenizer and dispersed at 1500 rpm for 2 minutes, a filler is added, and the mixture is placed in a homogenizer and dispersed at 1500 rpm for 5 minutes, an antioxidant is added and stirred, and the mixture is placed in a homogenizer and dispersed at 1500 rpm for 2 minutes, cooled, a cationic thermal initiator is added, and the mixture is placed in a homogenizer and dispersed at 1500 rpm for 2 minutes, vacuum degassed, cooled, and then dispersed in a homogenizer at 1500 rpm for 2 minutes, vacuum degassed, loaded with a rubber tube, and stored in a freezer to obtain the UV-heat dual-curing adhesive.

[0057] Comparative Examples 1-4

[0058] In Comparative Examples 1-4, a UV-heat dual-curing adhesive is provided respectively. The raw materials and dosage (parts by weight) of the UV-heat dual-curing adhesive are shown in Table 2, and the preparation method refers to Examples 1-5.

[0059] Table 2

[0060]

[0061] Comparative Example 5

[0062] The only difference between this comparative example and Example 1 is that the epoxy silicone resin (1,1,3,3-tetramethyl-1,3-bis-[2-[7-oxidobicyclo[4.1.0]hept-3-yl]ethyl]disiloxane) is replaced with an equal weight portion of γ-glycidyloxypropyltrimethoxysilane.

[0063] The UV-heat dual-curing adhesive provided in the embodiment and the comparative example was respectively applied between two aluminum silicon alloy (AlSi12) sheets and two anodized aluminum sheets, and then cured. The curing conditions were as follows: first, the energy density was 150 mW / cm 2 The film was photocured under UV light for 4 seconds and then thermally cured at 80°C for 60 minutes. The initial tensile shear strength and the tensile shear strength after being placed at 85°C and 85% humidity for 1000 hours were tested according to GB / T 7124-2008 standard. The performance test results are shown in Table 3.

[0064] Table 3

[0065]

[0066] It can be seen from Table 3 that the UV-heat dual-curing adhesives provided in the embodiments of the present invention have excellent adhesion and weather resistance (when the laminating substrate is AlSi12 / AlSi12, the initial tensile shear strength is 9.1-12.5 MPa, and the tensile shear strength after aging is 7.3-11.6 MPa; when the laminating substrate is anodized aluminum / anodized aluminum, the initial tensile shear strength is 9.2-12.3 MPa, and the tensile shear strength after aging is 7.2-11.5 MPa).

[0067] Compared with Example 1, the adhesion and weather resistance of the UV-heat dual-curing adhesives provided by Comparative Examples 1 and 2 are significantly reduced; the adhesion and weather resistance of the UV-heat dual-curing adhesive provided by Comparative Example 4 are significantly reduced; the adhesion and weather resistance of the UV-heat dual-curing adhesive provided by Comparative Example 5 are significantly reduced.

[0068] Compared with Example 3, the adhesion and weather resistance of the UV-heat dual-curing adhesive provided in Comparative Example 3 are significantly reduced.

[0069] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the UV-heat dual-curing adhesive and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A UV-heat dual-curing adhesive, characterized in that: The raw materials for preparing the UV-heat dual-curing adhesive include the following components in parts by weight:

2. The UV-heat dual-curing adhesive according to claim 1, characterized in that: The silicon-free epoxy resin includes any one of alicyclic epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, vinyl epoxy resin, hydrogenated bisphenol A epoxy resin or hydrogenated bisphenol F epoxy resin, or a combination of at least two thereof.

3. The UV-heat dual-curing adhesive according to claim 2, characterized in that: The silicon-free epoxy resin includes any one of bis-(3,4-epoxycyclohexylmethyl) adipate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, di-4-epoxycyclohexane, 1,2:5,6-diepoxyhexahydroindane, 4-vinylepoxycyclohexane, 3,4-epoxycyclohexyl methacrylate, and 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, or a combination of at least two thereof.

4. The UV-heat dual-curing adhesive according to claim 1, characterized in that: The epoxy silicone resin includes any one of 1,1,3,3-tetramethyl-1,3-bis-[2-[7-oxidobicyclo[4.1.0]hept-3-yl]ethyl]disiloxane, tetraepoxycyclohexylethyl-2,4,6,8-tetramethylcyclotetrasiloxane, and 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, or a combination of at least two thereof.

5. The UV-heat dual-curing adhesive according to claim 1, characterized in that: The active diluent includes any one of alkenyl ether active diluents, vinyl ketone acetal active diluents, epoxy active diluents, epoxidized triglyceride active diluents, oxetane active diluents, and mixed active diluents containing epoxy enol ether groups, or a combination of at least two thereof.

6. The UV-heat dual-curing adhesive according to claim 1, characterized in that: The cationic photoinitiator includes any one of aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, and aromatic ferrocenium salts, or a combination of at least two thereof; The cationic thermal initiator includes any one of CXC1612, Vicbase TC3631, Vicbase TC3632, Vicbase TC3634, CTI-100, CTI-200 or CTI-300, or a combination of at least two thereof.

7. The UV-heat dual-curing adhesive according to claim 1, characterized in that: The thixotropic agent includes fumed silica and / or precipitated silica; The antioxidant includes aromatic amine antioxidant and / or hindered phenol antioxidant; The filler includes spherical silica powder and / or talc powder.

8. A method for preparing a UV-heat dual-curing adhesive as claimed in any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The silicon-free epoxy resin, epoxy silicone resin, reactive diluent and cationic photoinitiator are mixed and heated until the cationic photoinitiator is dissolved, and then a thixotropic agent, a filler, an antioxidant and a cationic thermal initiator are added and mixed again to obtain the UV-heat dual-curing adhesive.

9. The preparation method according to claim 8, characterized in that: The preparation method specifically comprises the following steps: Mixing a silicon-free epoxy resin, an epoxy silicone resin, a reactive diluent, and a cationic photoinitiator under yellow light conditions, and heating until the cationic photoinitiator is dissolved, performing a first dispersion, then adding a thixotropic agent, performing a second dispersion, then adding a filler, performing a third dispersion, then adding an antioxidant, performing a fourth dispersion, cooling, adding a cationic thermal initiator, performing a fifth dispersion, cooling, and then performing a sixth dispersion to obtain the UV-heat dual-curing adhesive; The rotation speeds of the first dispersion, the second dispersion, the fourth dispersion, the fifth dispersion and the sixth dispersion are each independently 1300-1700 rpm, and the dispersion time is each independently 1-3 min; the rotation speed of the third dispersion is 1300-1700 rpm, and the dispersion time is 4-6 min; The fifth and sixth dispersions further include a vacuum degassing step.

10. Use of the UV-heat dual-curing adhesive as claimed in any one of claims 1 to 7 in electronic products, automobile manufacturing, communications or aerospace.

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