One-component epoxy adhesive and its preparation method and application

Abstract

The present invention provides a one-component epoxy adhesive, its preparation method, and application. The one-component epoxy adhesive comprises, by weight, 15-45 parts of a conventional epoxy resin, 5-20 parts of a modified epoxy resin, 5-10 parts of a core-shell toughening agent, and 10-30 parts of a curing agent; the modified epoxy resin comprises a polyurethane-modified epoxy resin. By adding specific amounts and types of the modified epoxy resin and the core-shell toughening agent, the one-component epoxy adhesive not only inhibits precipitation and migration of the adhesive but also exhibits high bond strength, excellent aging resistance, and thermal shock resistance, making it particularly suitable for bonding module lenses.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy resin adhesives, and particularly relates to a single-component epoxy adhesive and a preparation method and application thereof. Background Art

[0002] Epoxy resin adhesives are one of the most widely used adhesives due to their lack of volatile solvents, strong bonding, and excellent overall performance. Commonly used epoxy resin adhesives are two- or multi-component, requiring a specific formulation before use. This not only complicates application but also hinders thorough mixing due to the high viscosity of the adhesive components, significantly reducing the performance of the cured product. This is particularly true in the microelectronics industry, where small dispensing volumes place a high premium on uniform mixing. Single-component epoxy adhesives, on the other hand, eliminate mixing issues. A latent curing agent is added to the epoxy resin, and the reaction begins when heated to a certain temperature. This makes them widely used in the microelectronics industry. This is particularly true in the bonding of module lenses. To achieve stronger adhesion, module manufacturers apply plasma to the surface of engineering plastics. This high amount of light-shielding powder creates a very rough surface, creating numerous capillary gaps within the plastic. Glue can easily migrate onto these surfaces at room temperature or during the initial curing period. Migration to solder joints can affect subsequent soldering, or onto the lens itself, contaminating it and causing adverse effects.

[0003] To solve these problems, patent document: Japanese Patent Publication No. 11-1956662 immerses the substrate in a solution to allow it to adsorb several molecules to form an organic film, thereby changing the roughness of the substrate. However, this method easily contaminates the lens, is complex in process, and has limited application.

[0004] CN108641066A discloses an epoxy resin composition and its preparation method. The epoxy resin component of the epoxy resin composition includes a glycidyl ether epoxy resin, an alicyclic epoxy resin, and an alkyl-substituted spiro orthocarbonate expansion monomer; and the curing agent component includes a Lewis acid-amine complex and a liquid acid anhydride. The composition exhibits reduced cure shrinkage and viscosity, while improving curing activity, heat resistance, and bond strength. It can be used as a sealant or potting compound and is particularly suitable for sealing and bonding tiny gaps in electronic and electrical equipment, inertial navigation systems, and other devices. However, the composition's anti-precipitation performance needs to be further improved.

[0005] Therefore, developing an epoxy adhesive with excellent bonding performance, aging resistance, good resistance to cold and hot shock, less adhesive precipitation, reduced adhesive migration, and avoidance of lens contamination is a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0006] In response to the shortcomings of the prior art, the present invention provides a one-component epoxy adhesive, its preparation method, and its application. By incorporating specific amounts and types of modified epoxy resin and core-shell toughening agents, the one-component epoxy adhesive not only inhibits adhesive precipitation and migration, resulting in less precipitation on plasma-treated engineering plastics, but also exhibits high bond strength, excellent aging resistance, and thermal shock resistance, making it particularly suitable for bonding module lenses.

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

[0008] In a first aspect, the present invention provides a one-component epoxy adhesive, which comprises, by weight, 15 to 45 parts of ordinary epoxy resin, 5 to 20 parts of modified epoxy resin, 5 to 10 parts of core-shell structure toughening agent and 10 to 30 parts of curing agent; the modified epoxy resin comprises polyurethane modified epoxy resin.

[0009] In the present invention, by compounding the modified epoxy resin and the core-shell structure toughening agent with the epoxy resin at specific contents and types, the adhesive is not easily precipitated and migrated, thus avoiding contamination of the lens and causing adverse effects; and is conducive to improving the adhesive's bonding properties, aging resistance, and resistance to cold and hot shocks. The glue is easy to dispense and simple to operate. After the glue is fully cured, it has high reliability, is solvent-free, and is environmentally friendly.

[0010] In parts by weight, the one-component epoxy adhesive includes 15 to 45 parts of ordinary epoxy resin, for example, 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, 42 parts, 44 parts, etc.

[0011] In parts by weight, the one-component epoxy adhesive includes 5 to 20 parts of modified epoxy resin, for example, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, etc.

[0012] In parts by weight, the one-component epoxy adhesive includes 5 to 10 parts of core-shell structure toughening agent, for example, it can be 5.2 parts, 5.6 parts, 6 parts, 6.2 parts, 6.4 parts, 6.6 parts, 6.8 parts, 7 parts, 7.2 parts, 7.4 parts, 7.6 parts, 7.8 parts, 8 parts, 8.2 parts, 8.4 parts, 8.6 parts, 8.8 parts, 9 parts, 9.2 parts, 9.4 parts, 9.6 parts, 9.8 parts, etc.

[0013] In parts by weight, the one-component epoxy adhesive includes 10 to 30 parts of curing agent, for example, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, etc.

[0014] Preferably, the common epoxy resin includes bisphenol A epoxy resin and / or bisphenol F epoxy resin.

[0015] Preferably, the viscosity of the bisphenol A epoxy resin at 25° C. is 8,000 to 15,000 cps, for example, 9,000 cps, 10,000 cps, 11,000 cps, 12,000 cps, 13,000 cps, 14,000 cps, etc.

[0016] Preferably, the viscosity of the bisphenol F epoxy resin at 25° C. is 2000-8000 cps, for example, 3000 cps, 4000 cps, 5000 cps, 6000 cps, 7000 cps, etc.

[0017] In the present invention, the bisphenol A epoxy resin includes but is not limited to YL980 epoxy resin produced by Mitsubishi Chemical Corporation; the bisphenol F epoxy resin includes but is not limited to YL983U epoxy resin produced by Mitsubishi Chemical Corporation.

[0018] Preferably, the epoxy equivalent of the polyurethane modified epoxy resin is 150 to 650 g / eq, for example, 155 g / eq, 160 g / eq, 165 g / eq, 170 g / eq, 175 g / eq, 180 g / eq, 185 g / eq, 190 g / eq, 195 g / eq, 200 g / eq, 205 g / eq, 210 g / eq, 215 g / eq, 220 g / eq, 225 g / eq, 230 g / eq, 235 g / eq, 236 g / eq, 237 g / eq, 238 g / eq, 240 g / eq, 241 g / eq, 242 g / eq, 243 g / eq, 244 g / eq, 245 g / eq, 246 g / eq, 247 g / eq, 248 g / eq, 249 g / eq, 250 g / eq, 251 g / eq, 252 g / eq, 253 g / eq, 254 g / eq, 256 g / eq, 257 g / eq, 258 g / eq, 259 g / eq, 260 g / eq, 261 g / eq, 262 g / eq, 263 g / eq, 264 g / eq, 265 g / eq, 266 g / eq, 267 g / eq, 268 g / eq, 269 g / eq, 270 g / eq, 271 g / eq, 272 g / eq, 273 g / eq, 274 g / eq, 275 g / eq, 276 g / eq, 277 g / eq 5g / eq, 240g / eq, 250g / eq, 260g / eq, 280g / eq, 300g / eq, 340g / eq, 380g / eq, 400g / eq, 420g / eq, 460g / eq, 500g / eq, 540g / eq, 580g / eq, 600g / eq, 620g / eq, 640g / eq, etc., preferably 150-300g / eq, more preferably 160-240g / eq.

[0019] Preferably, the viscosity of the polyurethane-modified epoxy resin at 25° C. is 10,000 to 300,000 cps, for example, 12,000 cps, 14,000 cps, 16,000 cps, 18,000 cps, 20,000 cps, 25,000 cps, 30,000 cps, 35,000 cps, 40,000 cps, 45,000 cps, 50,000 cps, 56,000 cps, 60,000 cps, 65,000 cps, 70,000 cps, 80,000 cps, 100,000 cps, 120,000 cps, 140,000 cps, 160,000 cps, 180,000 cps, 200,000 cps, 220,000 cps, 240,000 cps, 260,000 cps, 280,000 cps, etc., preferably 10,000 to 70,000 cps, and more preferably 10,000 to 20,000 cps.

[0020] In the present invention, the polyurethane modified epoxy resin includes but is not limited to NEPR-133, NEPR133L produced by Nan Ya, EPU-133, EPU-300S, EPU-253 or EPU-301 produced by Shanghai Luohe High-tech Materials, etc.

[0021] Preferably, the mass ratio of the ordinary epoxy resin to the modified epoxy resin is (2-9):1, for example, it can be 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, etc., and is more preferably (2-3):1.

[0022] Preferably, the core-shell structure toughening agent includes a nano core-shell rubber epoxy resin toughening agent.

[0023] Preferably, the epoxy equivalent of the core-shell structure toughening agent is 150 to 350 g / eq, for example, it can be 160 g / eq, 180 g / eq, 200 g / eq, 210 g / eq, 220 g / eq, 230 g / eq, 240 g / eq, 250 g / eq, 260 g / eq, 270 g / eq, 280 g / eq, 290 g / eq, 300 g / eq, 310 g / eq, 320 g / eq, 330 g / eq, 340 g / eq, etc., and more preferably 200 to 310 g / eq.

[0024] Preferably, the viscosity of the core-shell structure toughening agent at 50°C is 2000-30000cps, for example, it can be 2200cps, 2400cps, 2600cps, 2800cps, 3000cps, 3500cps, 4000cps, 4500cps, 5000cps, 5500cps, 6000cps, 8000cps, 10000cps, 15000cps, 20000cps, 25000cps, etc., and more preferably 2000-6000cps.

[0025] Preferably, the rubber in the core-shell structure toughening agent includes styrene-butadiene rubber and / or polybutadiene rubber.

[0026] In the present invention, the core-shell structure toughening agent includes but is not limited to Kane Ace's MX-125, MX-154, MX-136, MX-158, MX-553, MX-416, Shanghai Luohe's EPX-125, etc.

[0027] Preferably, the curing agent comprises a thiol curing agent.

[0028] Preferably, the curing agent comprises at least one of TMMP, TEMPIC, PEMP or DPMP.

[0029] In the present invention, the TMMP, TEMPIC, PEMP or DPMP curing agent is a thiol curing agent produced by SC Organic Chemical Co., Ltd.

[0030] Preferably, the one-component epoxy adhesive further includes 0.1 to 1 parts of a stabilizer, for example, 0.2 parts, 0.3 parts, 0.4 parts, 0.6 parts, 0.8 parts, etc., in parts by weight.

[0031] Preferably, the stabilizer includes at least one of barbituric acid, Shanghai Hesheng Chemical 1300, Shikoku Chemical L07N, salicylic acid, lactic acid, citric acid, benzoic acid, phenylacetic acid, stearic acid, boric acid or fumaric acid.

[0032] Preferably, the one-component epoxy adhesive further comprises 1 to 3 parts of a thixotropic agent in parts by weight, for example, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, etc.

[0033] Preferably, the thixotropic agent includes white carbon black and / or organic bentonite.

[0034] In the present invention, the white carbon black includes but is not limited to Cabot TS-720, Evonik R202, etc.

[0035] Preferably, the one-component epoxy adhesive further comprises 1 to 5 parts of a coupling agent, for example, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, etc., in parts by weight.

[0036] Preferably, the coupling agent includes at least one of 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, a titanate coupling agent or an aluminate coupling agent.

[0037] Preferably, the one-component epoxy adhesive further includes 1 to 5 parts of accelerator in parts by weight, for example, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, etc.

[0038] Preferably, the accelerator comprises an imidazole adduct and / or a modified amine accelerator.

[0039] In the present invention, the accelerator includes but is not limited to PN-23J, PN-23, PN-H, and PN-40J from JICURE; EH-5057P and EH-5057PK from ADEKA; and FXR-1081, FXR-1020, 7501, and 7060 from Shikoku Chemical.

[0040] Preferably, the one-component epoxy adhesive further includes 0.1 to 1 parts of a defoamer, for example, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, etc., in parts by weight.

[0041] Preferably, the defoaming agent includes at least one of Deqian 6800, Shanghai Junjiang 854 or BYK-A530.

[0042] Preferably, the one-component epoxy adhesive further comprises 1 to 5 parts of color powder, for example, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, etc., in parts by weight.

[0043] In the present invention, the toner includes carbon black.

[0044] In a second aspect, the present invention provides a method for preparing the one-component epoxy adhesive according to the first aspect, the preparation method comprising the following steps:

[0045] Ordinary epoxy resin, modified epoxy resin, core-shell structure toughening agent and curing agent are mixed according to the formula to obtain the one-component epoxy adhesive.

[0046] Preferably, the mixed material further comprises at least one of a stabilizer, a thixotropic agent, a coupling agent, a promoter, a defoaming agent or a color powder.

[0047] Preferably, the preparation method of the one-component epoxy adhesive comprises:

[0048] (1) mixing a common epoxy resin, a modified epoxy resin, a core-shell structure toughening agent, a curing agent, and optionally a stabilizer, a coupling agent, a toner, and a defoaming agent to obtain a first mixture;

[0049] (2) mixing the first mixture obtained in step (1) with an optional thixotropic agent to obtain a second mixture;

[0050] (3) Mixing the second mixture obtained in step (2) with an optional accelerator to obtain the one-component epoxy adhesive.

[0051] Preferably, the mixing in step (1) is carried out under vacuum conditions.

[0052] Preferably, the mixing temperature in step (1) is 15-30°C, for example, 16°C, 18°C, 20°C, 22°C, 24°C, 26°C, 28°C, etc.

[0053] Preferably, the mixing speed in step (1) is 900-1100 rpm, for example, it can be 950 rpm, 980 rpm, 1000 rpm, 1020 rpm, 1040 rpm, 1060 rpm, 1080 rpm, etc.

[0054] Preferably, the mixing time in step (1) is 10 to 30 minutes, for example, 15 minutes, 20 minutes, 25 minutes, etc.

[0055] Preferably, the mixing time in step (2) is 1 to 3 hours, for example, 1.5 hours, 2 hours, 2.5 hours, etc.

[0056] Preferably, the mixing speed in step (3) is 500-800 rpm, for example, it can be 550 rpm, 600 rpm, 650 rpm, 700 rpm, 750 rpm, etc.

[0057] Preferably, the mixing time in step (1) is 1 to 3 hours, for example, 1.5 hours, 2 hours, 2.5 hours, etc.

[0058] In a third aspect, the present invention provides a use of the single-component epoxy adhesive according to the first aspect in bonding module lenses.

[0059] The numerical range described in the present invention includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] The single-component epoxy adhesive provided by the present invention is compounded with epoxy resin by modifying epoxy resin and core-shell structure toughening agent of specific content and type, so that the adhesive is not easy to precipitate and migrate, thereby avoiding contamination of the lens and causing adverse effects; and is conducive to improving the bonding performance, aging resistance and thermal shock resistance of the adhesive. The glue is easy to dispense and simple to operate. After the glue is fully cured, it has high reliability, is solvent-free, and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 Schematic diagram of glue precipitation on the surface of engineering plastics that have been treated with Plasma. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0064] Example 1

[0065] This embodiment provides a one-component epoxy adhesive, which includes, by weight, 35 parts of epoxy resin YL980, 15 parts of polyurethane-modified epoxy resin NEPR-133L, 10 parts of core-shell structure toughener MX-136, 0.1 parts of phenylacetic acid, 10 parts of curing agent TMMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 3 parts of carbon black, 1 part of defoamer 6800, 1 part of white carbon black (Bote TS-720) and 1 part of accelerator PN-H.

[0066] This embodiment provides a method for preparing a one-component epoxy adhesive, which specifically includes the following steps:

[0067] (1) According to the formula amount, epoxy resin YL980, polyurethane modified epoxy resin NEPR-133L, core-shell structure toughening agent MX-136, phenylacetic acid, curing agent TMMP, 3-glycidyloxypropyltrimethoxysilane, carbon black, and defoaming agent 6800 were added to a double planetary stirring kettle, and stirred for 20 minutes under vacuum at a temperature of 25°C and a stirring speed of 1000 rpm to obtain a first mixture;

[0068] (2) adding silica TS-720 to the first mixture obtained in step (1), stirring for 2 h at a temperature of 25° C. and a stirring speed of 1000 rpm under vacuum to obtain a second mixture;

[0069] (3) Adding accelerator PN-H to the first mixture obtained in step (2), stirring at 600 rpm for 2 h under vacuum conditions, mixing evenly and discharging the mixture to obtain the one-component epoxy adhesive.

[0070] Example 2

[0071] This embodiment provides a one-component epoxy adhesive, which includes, by weight, 30 parts of epoxy resin YL983U, 12 parts of polyurethane-modified epoxy resin NEPR-133L, 10 parts of core-shell structure toughener MX-136, 0.2 parts of phenylacetic acid, 10 parts of curing agent TEMPIC, 2 parts of 3-glycidyloxypropyltrimethoxysilane, 3 parts of carbon black, 1 part of defoamer 6800, 2 parts of white carbon black (Bote TS-720) and 3 parts of accelerator PN-H.

[0072] This embodiment provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0073] Example 3

[0074] This embodiment provides a one-component epoxy adhesive, which includes, by weight, 35 parts of epoxy resin YL980, 15 parts of polyurethane-modified epoxy resin EPU-301, 8 parts of core-shell structure toughener MX-136, 0.1 parts of barbituric acid, 30 parts of curing agent PETMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 1 part of carbon black, 0.5 parts of defoamer 6800, 3 parts of white carbon black (Cabot TS-720) and 1 part of accelerator PN-H.

[0075] This embodiment provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0076] Example 4

[0077] This embodiment provides a one-component epoxy adhesive, which includes, by weight, 35 parts of epoxy resin YL980, 15 parts of polyurethane-modified epoxy resin EPU-253, 10 parts of core-shell structure toughener MX-154, 0.1 parts of barbituric acid, 30 parts of curing agent PETMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 1 part of carbon black, 0.5 parts of defoamer 6800, 3 parts of white carbon black (Bote TS-720) and 1 part of accelerator PN-H.

[0078] This embodiment provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0079] Example 5

[0080] This embodiment provides a one-component epoxy adhesive, which includes, by weight, 45 parts of epoxy resin YL980, 5 parts of polyurethane-modified epoxy resin EPU-133, 5 parts of core-shell structure toughener MX-154, 0.1 parts of barbituric acid, 30 parts of curing agent PETMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 1 part of carbon black, 0.5 parts of defoamer 6800, 3 parts of white carbon black (Bote TS-720) and 1 part of accelerator PN-H.

[0081] This embodiment provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0082] Example 6

[0083] This embodiment provides a one-component epoxy adhesive, which includes, by weight, 40 parts of epoxy resin YL980, 10 parts of polyurethane modified epoxy resin NEPR-133, 5 parts of core-shell structure toughener MX-125, 1 part of L07N, 30 parts of curing agent PETMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 1 part of carbon black, 0.5 parts of defoamer 6800, 3 parts of white carbon black (Bote TS-720) and 1 part of accelerator PN-23.

[0084] This embodiment provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0085] Example 7

[0086] This embodiment provides a one-component epoxy adhesive, which differs from Example 1 only in that the total amount of the ordinary epoxy resin and the polyurethane-modified epoxy resin remains unchanged, with a mass ratio of 3.5:1. The other components, amounts and preparation methods are the same as those in Example 1.

[0087] Example 8

[0088] This embodiment provides a one-component epoxy adhesive, which differs from Example 1 only in that the total amount of the ordinary epoxy resin and the polyurethane-modified epoxy resin remains unchanged, with a mass ratio of 1.5:1. The other components, amounts and preparation methods are the same as those in Example 1.

[0089] Example 9

[0090] This embodiment provides a one-component epoxy adhesive, which differs from Example 1 only in that the polyurethane-modified epoxy resin is Taizhou Hengchuang Insulation 102C-3 in equal parts by weight, and the other components, amounts, and preparation methods are the same as those in Example 1.

[0091] Example 10

[0092] This embodiment provides a one-component epoxy adhesive, which differs from Example 1 only in that the polyurethane-modified epoxy resin is equal parts by weight of Japan's Kaneka MBS-701, and the other components, amounts and preparation methods are the same as those in Example 1.

[0093] Comparative Example 1

[0094] This comparative example provides a one-component epoxy adhesive, which includes, in parts by weight, 45 parts of epoxy resin YL980, 4 parts of epoxy resin YL983U, 5 parts of core-shell structure toughener MX-125, 0.1 parts of barbituric acid, 30 parts of curing agent PETMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 1 part of carbon black, 0.5 parts of defoaming agent 6800, 3 parts of white carbon black (Bote TS-720) and 1 part of accelerator PN-H.

[0095] This comparative example provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0096] Comparative Example 2

[0097] This comparative example provides a one-component epoxy adhesive, which includes, in parts by weight, 30 parts of epoxy resin YL980, 12 parts of epoxy resin YL983U, 0.1 parts of barbituric acid, 20 parts of curing agent PETMP, 1 part of 3-glycidyloxypropyltrimethoxysilane, 1 part of carbon black, 0.5 parts of defoamer 6800, 3 parts of white carbon black (Bote TS-720) and 1 part of accelerator PN-H.

[0098] This comparative example provides a method for preparing a one-component epoxy adhesive, and the specific steps are the same as those in Example 1.

[0099] Comparative Example 3

[0100] This comparative example provides a one-component epoxy adhesive, which differs from Example 1 only in that the polyurethane-modified epoxy resin is replaced by an equal weight portion of dicarboxylic acid-modified epoxy resin EPD-173. Other components, amounts, and preparation methods are the same as those in Example 1.

[0101] Comparative Example 4

[0102] This comparative example provides a one-component epoxy adhesive, which differs from Example 1 only in that the polyurethane-modified epoxy resin is replaced with an epoxy resin YL980 in equal parts by weight, and the other components, amounts, and preparation methods are the same as those in Example 1.

[0103] Comparative Example 5

[0104] This comparative example provides a one-component epoxy adhesive, which differs from Example 1 only in that the one-component epoxy adhesive does not contain a core-shell structure toughening agent, and the other components, amounts and preparation methods are the same as those in Example 1.

[0105] Performance Testing

[0106] (1) Precipitation inhibition performance:

[0107] Put glue on engineering plastic (LCP) with plasma, with a diameter of 1mm. Let it stand at room temperature for one hour, then put it in an oven and heat cure it at 80℃ for one hour. Then observe the glue precipitation part with a microscope (100 times) and measure the distance from the glue edge to the wet edge. Figure 1 As shown;

[0108] (2) Mechanical properties test:

[0109] Sample preparation:

[0110] S1. Draw a straight line 5 mm from one end of the substrate (LCP) to be tested (as the boundary of the glue-coated area) and perform three sets of data in parallel. If the test data deviates significantly, re-prepare the sample.

[0111] S2. Apply a small amount of glue (approximately 0.1 g) evenly to the area between one end of the substrate (LCP) to be tested and the straight line.

[0112] S3. Place the other test material (glass) on top of the LCP substrate coated with glue at one end. Place two 30-μm-diameter copper wires parallel to each other and squeeze the glue into a thin adhesive layer. Be careful not to have gaps or bubbles in the adhesive layer and minimize glue overflow. The resulting adhesive film thickness is 30 μm.

[0113] S4. Place the joined workpieces into an oven at 80°C for 30 minutes for curing.

[0114] S5. Place the cured workpiece at room temperature for 15 minutes, then place it in a universal tensile testing machine to test the tensile strength. Calculate the shear strength using the following formula: Shear strength (MPa) = average tensile strength (N) / bonding area (mm 2 );

[0115] (3) Aging resistance

[0116] The sample obtained in S5 was placed in an aging box for a double 85 test (85°C and 85% humidity). After 500 hours, it was taken out and the shear strength between the glass and the LPC substrate was tested according to the method in (2).

[0117] (4) Resistance to cold and heat shock

[0118] The sample obtained in S5 was subjected to thermal shock (first placed in a high temperature environment of 85°C for 0.5 hour, then immediately placed in a -40°C environment for 0.5 hour, which constituted one cycle). After 500 cycles, the shear strength between the glass and the LPC was tested.

[0119] (5) Anti-drop performance

[0120] Five samples of the samples obtained in S5 above were placed in a roller drop machine for each experiment. The drop height was 1000 mm, the drop speed was 20 times / min, and the drop was 500 times. The bonding interface was observed for cracks and the number of cracks was recorded.

[0121] The specific tests are shown in Table 1:

[0122] Table 1

[0123]

[0124] As can be seen from the table above, the one-component epoxy adhesive provided by the present invention, by adding specific amounts and types of modified epoxy resin and core-shell structure toughening agent, can not only inhibit the precipitation and migration of the adhesive, but also make the adhesive have high bonding strength, good aging resistance and resistance to cold and hot shock, and drop resistance. It is particularly suitable for bonding module lenses and has less precipitation on plasma-treated engineering plastics. As can be seen from Examples 1 to 6, the one-component epoxy adhesive has a precipitation distance of only 0.11 to 0.17 mm and a shear strength of 8.9 to 9.5 MPa. After aging for 500 hours at a temperature of 85°C and a humidity of 85%, the shear strength can still reach 6.4 to 7.1 MPa. After 500 cycles of cold and hot cycles, the shear strength can still reach 8.9 to 9.5 MPa. 1000 mm, a drop rate of 20 times / minute, and 500 drops without cracking.

[0125] It can be seen from Examples 1, 9 and 10 that the adhesive that is not a specific type of polyurethane-modified epoxy resin or core-shell structure toughening agent has poor anti-precipitation performance, mechanical properties, resistance to thermal shock, and drop resistance.

[0126] It can be seen from the examples and comparative examples that when the one-component structural adhesive does not contain polyurethane-modified epoxy resin, when the polyurethane-modified epoxy resin is replaced by dicarboxylic acid-modified epoxy resin, or when there is no core-shell structure toughening agent, the adhesive performance deteriorates.

[0127] In summary, the single-component adhesive provided by the present invention improves the problem of easy glue precipitation in the prior art by adding specific content and type of polyurethane modified epoxy resin and core-shell structure toughening agent, avoids the glue precipitation and diffusion on the substrate caused by other problems, and penetrates into the contacts or module lenses, causing adverse effects, greatly reduces the risk of precipitation contamination of contacts and lenses, and improves the qualified rate of products; and the adhesive has excellent bonding performance, aging resistance and cold and hot shock resistance, drop resistance, and is applicable to a variety of substrates, such as LCP, AL, SUS304, magnets, glass, NTB, etc.; the glue is easy to dispense and simple to operate; the glue has high reliability after complete curing; and it is solvent-free, environmentally friendly, and can meet many application scenarios. The applicant declares that the above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A one-component epoxy adhesive, characterized in that: In parts by weight, the one-component epoxy adhesive comprises 15 to 45 parts of ordinary epoxy resin, 5 to 20 parts of modified epoxy resin, 5 to 10 parts of core-shell structure toughening agent, 10 to 30 parts of curing agent and 0.1 to 1 part of defoaming agent; The modified epoxy resin includes polyurethane modified epoxy resin; The mass ratio of the ordinary epoxy resin to the modified epoxy resin is (2-9):1; The core-shell structure toughening agent includes a nano core-shell rubber epoxy resin toughening agent; The common epoxy resin includes bisphenol A epoxy resin and / or bisphenol F epoxy resin.

2. The one-component epoxy adhesive according to claim 1, characterized in that: The viscosity of the bisphenol A epoxy resin at 25° C. is 8000 to 15000 cps.

3. The one-component epoxy adhesive according to claim 1, characterized in that: The viscosity of the bisphenol F epoxy resin at 25° C. is 2000 to 8000 cps.

4. The one-component epoxy adhesive according to claim 1, characterized in that: The epoxy equivalent of the polyurethane modified epoxy resin is 150 to 650 g / eq.

5. The one-component epoxy adhesive according to claim 4, characterized in that: The epoxy equivalent of the polyurethane modified epoxy resin is 150 to 300 g / eq.

6. The one-component epoxy adhesive according to claim 5, characterized in that: The epoxy equivalent of the polyurethane modified epoxy resin is 160 to 240 g / eq.

7. The one-component epoxy adhesive according to claim 1, characterized in that: The viscosity of the polyurethane-modified epoxy resin at 25° C. is 10,000 to 300,000 cps.

8. The one-component epoxy adhesive according to claim 7, characterized in that: The viscosity of the polyurethane-modified epoxy resin at 25° C. is 10,000 to 70,000 cps.

9. The one-component epoxy adhesive according to claim 8, characterized in that: The viscosity of the polyurethane-modified epoxy resin at 25° C. is 10,000 to 20,000 cps.

10. The one-component epoxy adhesive according to claim 1, characterized in that: The mass ratio of the ordinary epoxy resin to the modified epoxy resin is (2-3):

1.

11. The one-component epoxy adhesive according to claim 1, characterized in that: The epoxy equivalent of the core-shell structure toughening agent is 150 to 350 g / eq.

12. The one-component epoxy adhesive according to claim 11, characterized in that: The epoxy equivalent of the core-shell structure toughening agent is 200 to 310 g / eq.

13. The one-component epoxy adhesive according to claim 1, characterized in that: The core-shell structure toughening agent has a viscosity of 2000 to 30000 cps at 50°C.

14. The one-component epoxy adhesive according to claim 13, characterized in that: The core-shell structure toughening agent has a viscosity of 2000-6000 cps at 50°C.

15. The one-component epoxy adhesive according to claim 1, characterized in that: The rubber in the core-shell structure toughening agent includes styrene-butadiene rubber and / or polybutadiene rubber.

16. The one-component epoxy adhesive according to claim 1, characterized in that: The curing agent includes a thiol curing agent.

17. The one-component epoxy adhesive according to claim 16, characterized in that: The curing agent includes at least one of TMMP, TEMPIC, PEMP or DPMP.

18. The one-component epoxy adhesive according to claim 1, characterized in that: The one-component epoxy adhesive further comprises 0.1 to 1 parts of a stabilizer in parts by weight.

19. The one-component epoxy adhesive according to claim 18, characterized in that: The stabilizer includes at least one of barbituric acid, Shanghai Hesheng Chemical 1300, Shikoku Chemical L07N, salicylic acid, lactic acid, citric acid, benzoic acid, phenylacetic acid, stearic acid, boric acid or fumaric acid.

20. The one-component epoxy adhesive according to claim 1, characterized in that: The one-component epoxy adhesive further comprises 1 to 3 parts of a thixotropic agent in parts by weight.

21. The one-component epoxy adhesive according to claim 20, characterized in that: The thixotropic agent includes white carbon black and / or organic bentonite.

22. The one-component epoxy adhesive according to claim 1, characterized in that: The one-component epoxy adhesive further comprises 1 to 5 parts of a coupling agent in parts by weight.

23. The one-component epoxy adhesive according to claim 22, characterized in that: The coupling agent includes at least one of 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, a titanate coupling agent or an aluminate coupling agent.

24. The one-component epoxy adhesive according to claim 1, characterized in that: The one-component epoxy adhesive further comprises 1 to 5 parts of an accelerator in parts by weight.

25. The one-component epoxy adhesive according to claim 24, characterized in that: The accelerator includes an imidazole adduct and / or a modified amine accelerator.

26. The one-component epoxy adhesive according to claim 1, characterized in that: The defoaming agent includes at least one of Deqian 6800, Shanghai Junjiang 854 or BYK-A530.

27. The one-component epoxy adhesive according to claim 1, characterized in that: The one-component epoxy adhesive further comprises 1 to 5 parts of color powder in parts by weight.

28. A method for preparing a one-component epoxy adhesive according to any one of claims 1 to 17, characterized in that: The preparation method comprises the following steps: Ordinary epoxy resin, modified epoxy resin, core-shell structure toughening agent, curing agent and defoaming agent are mixed according to the formula to obtain the one-component epoxy adhesive.

29. The preparation method according to claim 28, characterized in that The mixed material further comprises at least one of a stabilizer, a thixotropic agent, a coupling agent, a accelerator or a toner.

30. The preparation method according to claim 28, characterized in that The preparation method of the one-component epoxy adhesive comprises: (1) mixing a common epoxy resin, a modified epoxy resin, a core-shell structure toughening agent, a defoaming agent, a curing agent, and an optional stabilizer, a coupling agent, and a toner to obtain a first mixture; (2) mixing the first mixture obtained in step (1) with an optional thixotropic agent to obtain a second mixture; (3) Mixing the second mixture obtained in step (2) with an optional accelerator to obtain the one-component epoxy adhesive.

31. The preparation method according to claim 30, characterized in that The mixing in step (1) is carried out under vacuum conditions.

32. The preparation method according to claim 30, characterized in that The mixing temperature in step (1) is 15-30°C.

33. The preparation method according to claim 30, characterized in that The mixing speed in step (1) is 900-1100 rpm.

34. The preparation method according to claim 30, characterized in that The mixing time in step (1) is 10 to 30 minutes.

35. The preparation method according to claim 30, characterized in that The mixing time in step (2) is 1 to 3 hours.

36. The preparation method according to claim 30, characterized in that The mixing speed in step (3) is 500-800 rpm.

37. The preparation method according to claim 30, characterized in that The mixing time in step (1) is 1 to 3 hours.

38. Use of the single-component epoxy adhesive according to any one of claims 1 to 27 in bonding module lenses.

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