A plastic bonding sealant, its preparation method and application

Abstract

The application provides a plastic bonding sealant, a preparation method and application thereof. The plastic bonding sealant comprises silane modified polymers, plasticizers, fillers, curing agents, modified coupling agents and silane coupling agents in specific proportions, and the preparation raw materials of the modified coupling agents comprise epoxy silane and amino silane. The modified coupling agents and conventional silane coupling agents made by selecting the specific raw materials are matched and added into the silane modified polymer matrix for modification. The obtained plastic bonding sealant has excellent bonding performance on plastic substrates, is suitable for various plastic substrates, and also has excellent bonding performance on metal substrates, and has a very broad application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sealant and specifically relates to a plastic bonding sealant as well as a preparation method and application thereof. BACKGROUND

[0002] With the popularity and continuous enhancement of electronic products, the demand for sealant is also increasing. The sealant market presents a stable growth trend as a whole, and is widely used in the fields of electronics, construction, automobiles and the like. The sealant is mainly used for the packaging of circuit boards, the fixing and protection of components and the sealing of connectors in electronic products to ensure the waterproof, dustproof, moistureproof and insulating properties of electronic products.

[0003] At present, the silane-modified polymer sealant has the advantages and merits of silicone sealant and polyurethane sealant, and exhibits excellent mechanical properties, weather resistance, durability, high anti-displacement capacity, good adhesion, coating property, environmental friendliness, low contamination, excellent construction performance, storage performance and simple post-maintenance.

[0004] However, with the continuous rapid development of electronic products in recent years, there are many plastic substrates that need to be bonded in electronic and electrical products, such as PE plastic substrates, PC plastic substrates, PMMA plastic substrates, PP plastic substrates, PVC plastic substrates, PA plastic substrates, PET plastic substrates, PS plastic substrates and ABS plastic substrates, etc. The existing sealant has poor adhesion to plastic substrates, and is difficult to meet the use requirements of electronic products.

[0005] Therefore, in view of the above problems, it is urgent to develop a plastic bonding sealant with excellent adhesion to plastic substrates. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a plastic bonding sealant and a preparation method and application thereof. The plastic bonding sealant has excellent adhesion to plastic substrates, and is suitable for different types of plastic substrates. At the same time, the plastic bonding sealant also has excellent adhesion to metal substrates, and has very wide application.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a plastic bonding sealant, which comprises the following components by weight:

[0009]

[0010] The preparation raw material of the modified coupling agent comprises epoxy silane and amino silane.

[0011] The plastic bonding sealant provided by the present application comprises silane modified polymers, plasticizers, fillers, curing agents, modified coupling agents and silane coupling agents in specific proportions, and the preparation raw materials of the modified coupling agents are limited to epoxy silane and amino silane; the modified coupling agents and silane coupling agents prepared by selecting specific raw materials are matched and added to the silane modified polymers, so that the obtained plastic bonding sealant has excellent bonding performance on plastic substrates, and is suitable for various plastic substrates, including but not limited to PE, PC, PMMA, PP, PVC, PA, PET, PS, ABS and other plastic substrates; in addition, the bonding performance on metal substrates is also excellent, and the application is very wide.

[0012] The silane modified polymers can be used in an amount of 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight or 80 parts by weight, etc.

[0013] The plasticizers can be used in an amount of 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 12 parts by weight, 14 parts by weight or 15 parts by weight, etc.

[0014] The fillers can be used in an amount of 25 parts by weight, 27 parts by weight, 29 parts by weight, 31 parts by weight, 33 parts by weight, 35 parts by weight, 37 parts by weight, 39 parts by weight, 41 parts by weight, 43 parts by weight or 45 parts by weight, etc.

[0015] The curing agents can be used in an amount of 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight or 1.5 parts by weight, etc.

[0016] The modified coupling agents can be used in an amount of 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight or 1.5 parts by weight, etc.

[0017] The silane coupling agents can be used in an amount of 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight or 1.5 parts by weight, etc.

[0018] Preferably, the silane modified polymers comprise silane modified polyether and / or silane modified polyurethane, and further preferably silane modified polyurethane.

[0019] In the present application, the specific selection of the silane-modified polyether and the silane-modified polyurethane is not particularly limited; illustratively, the silane-modified polyether can be selected as any one or a combination of at least two of S203H, S303H, SAX260, SAX750, MAX440, MA451, and MA490 of kaneka company; the silane-modified polyurethane can be selected as any one or a combination of at least two of SX3430E, SX6735D, and S888E of AGC company, and XT502, STP-E15, STP-E35, STPE10, XT502, SPUR+*1015, SPUR+*1012, SPUR+*3030, and SPUR+*3040 of Momentive company; and further preferably the silane-modified polyether, and more further preferably any one or a combination of at least two of MAX440, MA451, and MA490 of kaneka company, because the three silane-modified polyethers are acryl-modified methylsiloxane-terminated silane-modified polyethers.

[0020] Preferably, the mass ratio of the epoxy silane and the amino silane is (4-6):1, such as 4:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1, 5:1, 5.2:1, 5.4:1, 5.6:1, 5.8:1, or 6:1, etc.

[0021] Preferably, the epoxy silane includes any one or a combination of at least two of 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, and 3-glycidyloxypropyl methyl diethoxysilane.

[0022] Preferably, the amino silane includes any one or a combination of at least two of γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, phenylamino-silane, and triaminosilane.

[0023] Preferably, the modified coupling agent is obtained by the reaction of the epoxy silane and the amino silane, both of which have high reactivity, and the ring-opening reaction can occur even without the addition of a catalyst.

[0024] Preferably, the temperature of the reaction is 20-40℃, such as 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃, 36℃, 38℃, or 40℃, etc.

[0025] Preferably, the temperature of the reaction is 72-96h, such as 72h, 76h, 80h, 84h, 88h, 90h, 92h, 94h, or 96h, etc.

[0026] ​Preferably, the plasticizer comprises phthalate compounds and / or polyether polyols, further preferably polyether polyols.

[0027] Preferably, the phthalate compounds comprise any one or a combination of at least two of diisononyl phthalate, diisooctyl phthalate or diisodecyl phthalate.

[0028] Preferably, the polyether polyols have a number average molecular weight of 900-9000, such as 900, 1000, 2000, 4000, 6000 or 8000, etc.

[0029] Preferably, the polyether polyols comprise polypropylene glycol.

[0030] In the present application, the selection of the polypropylene glycol is not particularly limited, and exemplarily, the polypropylene glycol can be selected from any one or a combination of at least two of PPG1000, PPG2000, PPG3000, PPG4000 or PPG8000.

[0031] Preferably, the filler comprises any one or a combination of at least two of aluminum hydroxide, calcium carbonate, clay, talc, carbon black or organic bentonite.

[0032] Preferably, the curing agent comprises chelated tin curing agent, such as any one or a combination of at least two of commercially available U-220 type curing agent, U303 type curing agent, TIB 226 type curing agent or organic tin DBTDL curing agent.

[0033] Preferably, the silane coupling agent comprises any one or a combination of at least two of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, phenylamino-silane, triaminosilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane and γ-ureidopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane or γ-glycidyl ether propyltrimethoxysilane.

[0034] Preferably, the plastic bonding sealant further comprises any one or a combination of at least two of thixotropic agent, ultraviolet absorber, light stabilizer, heat stabilizer or water removal agent.

[0035] Preferably, the content of the thixotropic agent in the plastic bonding sealant is 0.5-1.5 parts by weight, such as 0.5 parts by weight, 0.7 parts by weight, 0.9 parts by weight, 1.1 parts by weight, 1.3 parts by weight or 1.5 parts by weight, etc.

[0036] Preferably, the thixotropic agent comprises any one or a combination of at least two of polyamide wax, hydrogenated castor oil or white carbon black.

[0037] Preferably, the content of the ultraviolet absorber in the plastic bonding sealant is 0.2-1 parts by weight, for example, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, or 0.8 parts by weight, etc.

[0038] Preferably, the ultraviolet absorber comprises a benzotriazole ultraviolet absorber.

[0039] Preferably, the content of the light stabilizer in the plastic bonding sealant is 0.2-1 parts by weight, for example, 0.2 parts by weight, 0.4 parts by weight, 0.6 parts by weight, 0.8 parts by weight, or 1 part by weight, etc.

[0040] Preferably, the light stabilizer comprises a hindered amine light stabilizer.

[0041] In the present application, there is no special requirement for the selection of the hindered amine light stabilizer, and exemplarily, any one or a combination of at least two of commercially available brands of light stabilizer 292, light stabilizer 770, light stabilizer 765, light stabilizer 622, or light stabilizer 5050H can be selected.

[0042] Preferably, the content of the heat stabilizer in the plastic bonding sealant is 0.2-1 parts by weight, for example, 0.2 parts by weight, 0.4 parts by weight, 0.6 parts by weight, 0.8 parts by weight, or 1 part by weight, etc.

[0043] Preferably, the heat stabilizer comprises a hindered phenol heat stabilizer and / or a phosphite heat stabilizer.

[0044] In the present application, there is no special limitation on the specific selection of the hindered phenol heat stabilizer and the phosphite heat stabilizer, and exemplarily, the hindered phenol heat stabilizer can be selected from 1076 and / or 245 of BASF, and the phosphite heat stabilizer can be selected from Irgafos 168 and / or Vanlube CA-SF.

[0045] Preferably, the content of the water removing agent in the plastic bonding sealant is 0.5-1.5 parts by weight, for example, 0.5 parts by weight, 0.7 parts by weight, 0.9 parts by weight, 1.1 parts by weight, 1.3 parts by weight, 1.5 parts by weight, 1.7 parts by weight, or 1.9 parts by weight, etc.

[0046] Preferably, the water removing agent comprises vinyltrimethoxysilane and / or vinyltriethoxysilane.

[0047] In a second aspect, the present application provides a method for preparing the sealant for plastic bonding as described in the first aspect, the method comprising: mixing the silane-modified polymer, the plasticizer, the filler, optionally the thixotropic agent, optionally the ultraviolet absorber, optionally the light stabilizer, and optionally the heat stabilizer, adding the optional water-removing agent and mixing, adding the modified coupling agent and the silane coupling agent and mixing, and finally adding the curing agent and mixing, to obtain the sealant for plastic bonding.

[0048] In a limited embodiment, the method comprises: mixing the silane-modified polymer, the plasticizer, the filler, optionally the thixotropic agent, optionally the ultraviolet absorber, optionally the light stabilizer, and optionally the heat stabilizer at 20-50°C (for example 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, or 50°C, etc.) and 600-800 rpm (for example 600 rpm, 650 rpm, 700 rpm, 750 rpm, or 800 rpm, etc.) for 50-70 min (for example 50 min, 55 min, 60 min, 65 min, or 70 min, etc.), increasing the temperature to 100-120°C (for example 100°C, 105°C, 110°C, 115°C, or 120°C, etc.), continuing to mix at 300-600 rpm (for example 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, 550 rpm, or 600 rpm, etc.) for 100-130 min (for example 100 min, 105 min, 110 min, 115 min, 120 min, 125 min, or 130 min, etc.), decreasing the temperature to 40-50°C (for example 40°C, 42°C, 44°C, 46°C, 48°C, or 50°C, etc.), adding the water-removing agent and mixing at 200-300 rpm (for example 200 rpm, 205 rpm, 210 rpm, 215 rpm, 220 rpm, 225 rpm, or 230 rpm, etc.) for 10-30 min (for example 10 min, 15 min, 20 min, 25 min, or 30 min, etc.), adding the modified coupling agent and the silane coupling agent and mixing at 200-300 rpm (for example 200 rpm, 205 rpm, 210 rpm, 215 rpm, 220 rpm, 225 rpm, or 230 rpm, etc.) for 20-30 min (for example 20 min, 22 min, 24 min, 26 min, 28 min, or 30 min, etc.), and finally adding the curing agent and mixing at 200-300 rpm (for example 200 rpm, 205 rpm, 210 rpm, 215 rpm, 220 rpm, 225 rpm, or 230 rpm, etc.) for 20-30 min (for example 20 min, 22 min, 24 min, 26 min, 28 min, or 30 min, etc.), to obtain the sealant for plastic bonding.

[0049] In a third aspect, the present application provides an application of the sealant for plastic bonding in electronic and electrical products according to the first aspect.

[0050] Preferably, the plastic comprises any one of PE, PC, PMMA, PP, PVC, PA, PET, PS or ABS or a combination of at least two thereof.

[0051] Compared with the prior art, the present application has the following beneficial effects:

[0052] The sealant for plastic bonding provided by the present application comprises silane-modified polymers, plasticizers, fillers, curing agents, modified coupling agents and silane coupling agents in specific proportions, and the raw materials for preparing the modified coupling agents comprise epoxy silane and amino silane; by selecting the modified coupling agents made from the above-mentioned specific raw materials and the conventional silane coupling agents for matching, adding them into the silane-modified polymer matrix for modification, the obtained sealant for plastic bonding can have excellent bonding performance on plastic substrates, and is suitable for various plastic substrates, and also has excellent bonding on metal substrates, and has a very wide range of applications. DETAILED DESCRIPTION

[0053] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0054] Some raw material information involved in the following examples and comparative examples is shown as follows:

[0055] (A) Silane-modified polymers

[0056] A-1: Silane-modified polyether, purchased from kaneka company, with model number MA440;

[0057] A-2: Silane-modified polyether, purchased from kaneka company, with model number MA451;

[0058] A-3: Silane-modified polyether, purchased from kaneka company, with model number MA490;

[0059] A-4: Silane-modified polyether, purchased from kaneka company, with model number S203H;

[0060] A-5: Silane-modified polyurethane, purchased from AGC company, with model number SX3430E;

[0061] A-6: Silane-modified polyurethane, purchased from Momentive company, with model number SPUR+*1015.

[0062] (B) Plasticizers

[0063] B-1: polyether polyol, specifically PPG 1000;

[0064] B-2: diisononyl phthalate.

[0065] (C) filler:

[0066] C-1: aluminum hydroxide, D 50 The particle size is 8 μm.

[0067] (D) curing agent:

[0068] D-1: chelated tin curing agent, specifically organic tin DBTDL.

[0069] (E) modified coupling agent

[0070] E-1: obtained by reacting 3-glycidyloxypropyltriethoxysilane and γ- aminopropyltrimethoxysilane in a mass ratio of 5:1 at room temperature for 72 h;

[0071] E-2: obtained by reacting 3-glycidyloxypropyltrimethoxysilane and γ- aminopropyltrimethoxysilane in a mass ratio of 4:1 at room temperature for 72 h;

[0072] E-3: obtained by reacting 3-glycidyloxypropyltrimethoxysilane and γ- aminopropyltriethoxysilane in a mass ratio of 6:1 at room temperature for 72 h.

[0073] (F) silane coupling agent

[0074] F-1: γ-aminopropyltrimethoxysilane;

[0075] F-2: γ-mercaptopropyltrimethoxysilane;

[0076] F-3: γ-methacryloyloxypropyltrimethoxysilane.

[0077] (G) thixotropic agent

[0078] G-1: polyamide wax;

[0079] G-2: hydrogenated castor oil;

[0080] G-3: white carbon black.

[0081] (H) ultraviolet absorber

[0082] H-1: benzotriazole ultraviolet absorber, specifically Tinuvin 326 of BASF Corporation.

[0083] (I) light stabilizer

[0084] I-1: hindered amine light stabilizer, specifically light stabilizer 292;

[0085] I-2: Hindered amine light stabilizer, specifically Chimassorb® 119

[0086] I-3: Hindered amine light stabilizer, specifically Tinuvin® 770

[0087] (J) Thermal stabilizer

[0088] J-1: Hindered phenolic thermal stabilizer, specifically Irgafos® 1076

[0089] J-2: Phosphite thermal stabilizer, specifically Irgafos® 168

[0090] (K) Other coupling agent

[0091] K-1: 3-glycidyloxypropyltriethoxysilane

[0092] K-2: Gamma-aminopropyltrimethoxysilane

[0093] Examples 1-7 and Comparative Examples 1-5

[0094] Examples 1-7 and Comparative Examples 1-5 each provide a sealant for plastic bonding, which includes each component and the amount as shown in Table 1 and Table 2.

[0095] In Table 1 and Table 2, the amount of each component is in "parts by weight";

[0096] Table 1

[0097]

[0098] Table 2

[0099]

[0100] The method for preparing the sealant for plastic bonding provided by Examples 1-7 and Comparative Examples 1-5 includes the following steps:

[0101] Mixing the silane-modified polymer, plasticizer, filler, thixotropic agent, ultraviolet absorber, light stabilizer, and thermal stabilizer at 30°C and 700 rpm for 60 min, increasing the temperature to 110°C, and continuing to mix at 500 rpm for 120 min, decreasing the temperature to 45°C, adding the water removal agent and mixing at 250 rpm for 20 min, adding the modified coupling agent (or other coupling agent) and silane coupling agent and mixing at 250 rpm for 25 min, and finally adding the curing agent and mixing at 250 rpm for 25 min to obtain the sealant for plastic bonding.

[0102] Performance test:

[0103] (1) Bonding performance: test the bonding strength on different substrates according to GB / T 43747-2024 "Evaluation of sealant adhesion by tape-peeling method", and determine the failure area and failure type according to the standard provided by GB / T 16997-1997 "Representation of main failure types of adhesives".

[0104] Wherein, CF is cohesive failure, and AF is interfacial peeling. Exemplarily: 10CF represents 100% cohesive failure, 100AF% represents 100% interfacial peeling, and 5CF / 5AF represents 50% cohesive failure and 50% interfacial peeling.

[0105] The sealant for plastic bonding provided by Examples 1-7 and Comparative Examples 1-5 was tested according to the above test method, and the test results are shown in Table 3:

[0106] Table 3

[0107]

[0108] According to the data in Table 3, it can be seen that:

[0109] The sealant for plastic bonding provided by Examples 1-7 has excellent adhesion to different plastic substrates, and also has excellent adhesion to metal substrates. In particular, the sealant for plastic bonding provided by Examples 1-3 has up to 80% cohesive failure to PE plastic, and up to 100% cohesive failure to PMMA plastic, PC plastic, PVC plastic, PS plastic and ABS plastic. Also, it can achieve 100% cohesive failure to 6-series aluminum and 5-series aluminum.

[0110] The sealant for plastic bonding provided by Comparative Examples 1-5 cannot achieve excellent adhesion to all plastic substrates.

[0111] The applicant declares that the present application illustrates a sealant for plastic bonding, its preparation method and application through the above examples, but the present application is not limited to the above examples, that is, it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement on the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the scope of protection and disclosure of the present application.

Claims

1. A sealant for plastic bonding, characterized by, The plastic bonding sealant comprises the following components by weight: The silane modified polymer 40-80 parts by weight; The plasticizer 5-15 parts by weight; The filler 25-45 parts by weight; The curing agent 0.5-1.5 parts by weight; The modified coupling agent 0.5-1.5 parts by weight; The silane coupling agent 0.5-1.5 parts by weight; The raw materials of the modified coupling agent include epoxy silane and amino silane; The silane modified polymer includes silane modified polyether and / or silane modified polyurethane.

2. The sealant for plastic bonding according to claim 1, wherein The silane modified polymer is silane modified polyether.

3. The sealant for plastic bonding according to claim 1, wherein The mass ratio of the epoxy silane and the amino silane is (4-6):

1.

4. The sealant for plastic bonding according to claim 1, wherein The epoxy silane includes any one or a combination of at least two of 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane or 3-glycidyloxypropyl methyl diethoxysilane.

5. The sealant for plastic bonding according to claim 1, wherein The amino silane includes any one or a combination of at least two of γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, phenylamino-silane or triaminosilane.

6. The sealant for plastic bonding according to claim 1, wherein The modified coupling agent is obtained by the reaction of the epoxy silane and the amino silane.

7. The sealant for plastic bonding according to claim 6, wherein The reaction temperature is 20-40℃ and the reaction time is 72-96 hours.

8. The sealant for plastic bonding according to claim 1, wherein The plasticizer includes phthalate compound and / or polyether polyol.

9. The sealant for plastic bonding according to claim 8, wherein The plasticizer is polyether polyol.

10. The sealant for plastic bonding according to claim 8, wherein The phthalate compound includes any one or a combination of at least two of diisononyl phthalate, diisooctyl phthalate or diisodecyl phthalate.

11. The sealant for plastic bonding according to claim 8, wherein The number average molecular weight of the polyether polyol is 900-9000.

12. The plastic bonding sealant of claim 8, wherein The polyether polyol includes polypropylene glycol.

13. The plastic bonding sealant of claim 1, wherein The filler includes any one or a combination of at least two of aluminum hydroxide, calcium carbonate, clay, talc, carbon black or organic bentonite.

14. The plastic bonding sealant of claim 1, wherein The curing agent includes chelated tin curing agent.

15. The sealant for plastic bonding according to claim 1, wherein The silane coupling agent includes any one or a combination of at least two of γ-aminopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, phenylamino-silane, triaminosilane, γ-mercaptopropyl trimethoxysilane, γ-ureidopropyl trimethoxysilane and γ-ureidopropyl triethoxysilane, γ-methacryloyloxypropyl trimethoxysilane or γ-glycidyloxypropyl trimethoxysilane.

16. The sealant for plastic bonding according to claim 1, wherein The plastic bonding sealant further comprises any one or a combination of at least two of thixotropic agent, ultraviolet absorber, light stabilizer, heat stabilizer or water removing agent.

17. The plastic bonding sealant of claim 16, wherein, The content of the thixotropic agent in the plastic bonding sealant is 0.5-1.5 parts by weight.

18. The plastic bonding sealant of claim 16, wherein, The thixotropic agent includes any one or a combination of at least two of polyamide wax, hydrogenated castor oil or white carbon black.

19. The plastic bonding sealant of claim 16, wherein The content of the ultraviolet absorber in the plastic bonding sealant is 0.2-1 part by weight.

20. The plastic bonding sealant of claim 16, wherein, The ultraviolet absorber includes benzotriazole ultraviolet absorber.

21. The plastic bonding sealant of claim 16, wherein The content of the light stabilizer in the plastic bonding sealant is 0.2-1 part by weight.

22. The plastic bonding sealant of claim 16, wherein The light stabilizer includes hindered amine light stabilizer.

23. The plastic bonding sealant of claim 16, wherein The content of the heat stabilizer in the plastic bonding sealant is 0.2-1 part by weight.

24. The plastic bonding sealant of claim 16, wherein, The heat stabilizer comprises a hindered phenol heat stabilizer and / or a phosphite heat stabilizer.

25. The plastic bonding sealant of claim 16, wherein, The content of the water removal agent in the plastic bonding sealant is 0.5-1.5 parts by weight.

26. The plastic bonding sealant of claim 16, wherein The water removal agent comprises vinyltrimethoxysilane and / or vinyltriethoxysilane.

27. A method of preparing a sealant for plastic bonding according to any one of claims 1 to 26, characterized in that The preparation method comprises: mixing a silane-modified polymer, a plasticizer, a filler, optionally a thixotropic agent, optionally an ultraviolet absorber, optionally a light stabilizer, and optionally a heat stabilizer, adding and mixing an optional water removal agent, adding and mixing a modified coupling agent and a silane coupling agent, and finally adding and mixing a curing agent to obtain the plastic bonding sealant.

28. The method of claim 27, wherein, The preparation method comprises: mixing a silane-modified polymer, a plasticizer, a filler, optionally a thixotropic agent, optionally an ultraviolet absorber, optionally a light stabilizer, and optionally a heat stabilizer at 20-50°C and 600-800 rpm for 50-70 min, heating to 100-120°C, continuing to mix at 300-600 rpm for 100-130 min, cooling to 40-50°C, adding a water removal agent and mixing at 200-300 rpm for 10-30 min, adding a modified coupling agent and a silane coupling agent and mixing at 200-300 rpm for 20-30 min, and finally adding a curing agent and mixing at 200-300 rpm for 20-30 min to obtain the plastic bonding sealant.

29. Use of the plastic bonding sealant according to any one of claims 1-26 in electronic and electrical products.

30. The use according to claim 29, characterized in that, The plastic comprises any one of PE plastic, PC plastic, PMMA plastic, PP plastic, PVC plastic, PA plastic, PET plastic, PS plastic, or ABS plastic, or a combination of at least two thereof.

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