Addition type organic silica gel as well as preparation method and application thereof

Abstract

The invention relates to addition type organic silica gel as well as a preparation method and application thereof. The addition type organic silica gel is prepared from the following components in parts by mass: 20 to 90 parts of vinyl-terminated polydimethylsiloxane, 5 to 55 parts of a cross-linking agent, 10 to 30 parts of a chain extender, 0.1 to 0.5 part of a coupling agent, 0.1 to 5 parts of a platinum catalyst, 0.001 to 0.02 part of an inhibitor and 0.1 to 0.5 part of a tackifier. The chain extender comprises methyl hydrogen silicone oil; and the coupling agent is prepared from gamma-methacryloxy propyl triethoxy silane. According to the addition type organic silica gel, a polar group is introduced through vinyl-terminated polydimethylsiloxane, and the vinyl-terminated polydimethylsiloxane is matched with the cross-linking agent, the chain extender, the coupling agent, the platinum catalyst, the inhibitor and the tackifier in a specific mass ratio for synergistic interaction, so that the cohesiveness of the addition type organic silica gel is improved, and the cohesiveness is not easy to quickly decrease along with time; and the instant bonding force is improved, and rapid bonding can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of adhesives, and in particular to an addition-type organic silica gel and a preparation method and application thereof. Background Art

[0002] Addition-type silicone rubber usually uses vinyl-containing polyorganosiloxane and silicon-hydrogen bond-containing polyorganosiloxane as raw materials, and forms elastomeric silicone materials through cross-linking through hydrosilylation reaction under the action of catalyst. Addition-type silicone rubber is widely used because of its excellent surface energy, thermal stability and low-temperature flexibility, good elasticity after curing, and good environmental performance. However, the adhesion of current addition-type silicone rubber needs to be improved, and it cannot be bonded quickly, resulting in the inability to quickly flow production, which limits the application of addition-type silicone rubber in more fields. Summary of the invention

[0003] Based on this, it is necessary to provide addition-type organic silica gel and its preparation method and application which can improve adhesion and instantaneous adhesion.

[0004] In one aspect of the present application, an addition-type organic silica gel is provided, wherein the raw materials for preparing the addition-type organic silica gel include the following components in parts by weight: 20 to 90 parts of vinyl-terminated polydimethylsiloxane, 5 to 55 parts of a cross-linking agent, 10 to 30 parts of a chain extender, 0.1 to 0.5 parts of a coupling agent, 0.1 to 5 parts of a platinum catalyst, 0.001 to 0.02 parts of an inhibitor, and 0.1 to 0.5 parts of a tackifier;

[0005] The chain extender includes methyl hydrogen silicone oil;

[0006] The coupling agent includes γ-methacryloxypropyltriethoxysilane.

[0007] The above-mentioned addition-type organic silicone introduces polar groups through vinyl-terminated polydimethylsiloxane, and is combined with a cross-linking agent, a chain extender, a coupling agent, a platinum catalyst, an inhibitor and a tackifier in a specific mass ratio to achieve synergistic effects, which not only improves the adhesion of the addition-type organic silicone, but also makes the adhesion less likely to decrease rapidly over time, and improves the instantaneous adhesion, enables rapid bonding, and further allows rapid assembly line operations, thereby broadening the application field of the addition-type organic silicone.

[0008] The above-mentioned addition-type organic silica gel is synergistically enhanced by the combination of vinyl-terminated polydimethylsiloxane containing polar groups, methyl hydrogen silicone oil and silane coupling agent γ-methacryloxypropyl triethoxysilane, which increases the bonding performance of the addition-type organic silica gel and improves the cohesive performance of the addition-type organic silica gel. Among them, γ-methacryloxypropyl triethoxysilane reacts with the trace amount of water contained in the raw materials, and after hydrolysis, it is freed on the surface of the adhesive layer of the addition-type organic silica gel to generate free radicals with a certain reactivity, so that the glue of the addition-type organic silica gel is coupled with the substrate during bonding, further increasing the adhesion of the addition-type organic silica gel.

[0009] The above-mentioned addition-type organic silica gel has high transmittance, low haze, good appearance transparency, and is not prone to yellowing.

[0010] The above-mentioned addition-type organic silicone has strong bonding force, and the viscosity at 25°C is 4000mPa·s~6000mPa·s, which is lower in viscosity and easier to mix evenly than traditional silicone. The above-mentioned addition-type organic silicone has excellent surface energy, thermal stability, and low-temperature flexibility.

[0011] In some embodiments, in the preparation raw materials, by weight, the vinyl-terminated polydimethylsiloxane is 50 to 90 parts; the cross-linking agent is 5 to 30 parts; the chain extender is 10 to 20 parts; the coupling agent is 0.2 to 0.5 parts; the platinum catalyst is 0.1 to 2 parts; the inhibitor is 0.01 to 0.02 parts; and the tackifier is 0.1 to 0.3 parts.

[0012] In some embodiments, the degree of polymerization of the vinyl terminated polydimethylsiloxane is 200-6000; and / or the viscosity of the vinyl terminated polydimethylsiloxane at 25° C. is 500 mPa·s-10000 mPa·s.

[0013] In some embodiments, the viscosity of the methyl hydrogen silicone oil at 25° C. is 20 mPa·s to 50 mPa·s.

[0014] In some embodiments, the tackifier is an acryloxy-containing tackifier;

[0015] Optionally, the adhesion promoter includes at least one of γ-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, methacryloxyethyltrimethylammonium chloride copolymer and γ-methacryloxypropyl-containing organic silicon adhesion promoter.

[0016] In some embodiments, the addition-type organic silica gel satisfies at least one of the following conditions:

[0017] (1) The crosslinking agent comprises a side-containing hydrogenated polydimethylsiloxane, wherein the degree of polymerization of the side-containing hydrogenated polydimethylsiloxane is 20 to 40; and / or, in the side-containing hydrogenated polydimethylsiloxane, the mass of hydrogen atoms accounts for 0.08% to 1.2% of the mass of the side-containing hydrogenated polydimethylsiloxane;

[0018] (2) The inhibitor is at least one of tetramethyldivinyldisiloxane, tetramethyltetravinylcyclotetrasiloxane, 2-methyl-3-butyn-2-ol, ethynylcyclohexanol, diallyl maleate and diisooctyl maleate.

[0019] The second aspect of the present application provides a method for preparing the addition-type organic silica gel as described in the first aspect, comprising the following steps:

[0020] The vinyl-terminated polydimethylsiloxane, the cross-linking agent, the chain extender, the coupling agent, the platinum catalyst, the inhibitor and the tackifier are mixed according to the mass fractions of the raw materials to prepare a mixture;

[0021] The mixed material is subjected to a degassing treatment to obtain the addition-type organic silica gel.

[0022] In some embodiments, the mixture satisfies at least one of the following conditions:

[0023] (1) The mixing is performed by vacuum mixing;

[0024] (2) The ambient temperature of the mixing material is 20°C to 35°C;

[0025] (3) The mixing time of the mixing is 0.5h~2h;

[0026] (4) The step of preparing the mixed material comprises the following steps:

[0027] The platinum catalyst is first dissolved in the vinyl-terminated polydimethylsiloxane, and then the cross-linking agent, chain extender, coupling agent, inhibitor and tackifier are added to mix.

[0028] The third aspect of the present application provides a use of the addition-type organic silica gel as described in the first aspect in the preparation of electronic devices.

[0029] The fourth aspect of the present application provides an electronic device, comprising the addition-type organic silica gel as described in the first aspect, or the addition-type organic silica gel prepared by the preparation method of the addition-type organic silica gel as described in the second aspect. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to relevant embodiments. Preferred embodiments of the present invention are given in the text. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] Addition-type organic silicone is widely used because of its excellent surface energy, thermal stability and low-temperature flexibility, good elasticity after curing, and good environmental performance. However, although addition-type organic silicone has good flexibility and elasticity, compared with some high-performance engineering plastics or rubbers, its mechanical properties such as tensile strength and tear strength are relatively low, which is subject to certain limitations in application scenarios that need to withstand high loads or high stresses. Moreover, the adhesion of addition-type organic silicone needs to be improved, and it cannot bond quickly, resulting in the inability to quickly produce products, thus limiting the application of addition-type organic silicone in more fields.

[0032] Based on this, one embodiment of the present application provides an addition-type organic silica gel, the raw materials for preparing the organic silica gel include the following components in parts by mass: 20 to 90 parts of vinyl-terminated polydimethylsiloxane, 5 to 55 parts of a cross-linking agent, 10 to 30 parts of a chain extender, 0.1 to 0.5 parts of a coupling agent, 0.1 to 5 parts of a platinum catalyst, 0.001 to 0.02 parts of an inhibitor, and 0.1 to 0.5 parts of a tackifier; the chain extender includes methyl hydrogen silicone oil; the coupling agent includes γ-methacryloxypropyltriethoxysilane.

[0033] The above-mentioned addition-type organic silicone introduces polar groups through vinyl-terminated polydimethylsiloxane, and is combined with a cross-linking agent, a chain extender, a coupling agent, a platinum catalyst, an inhibitor and a tackifier in a specific mass ratio to achieve synergistic effects, which not only improves the adhesion of the addition-type organic silicone, but also makes the adhesion less likely to decrease rapidly over time, and improves the instantaneous adhesion, enables rapid bonding, and further allows rapid assembly line operations, thereby broadening the application field of the addition-type organic silicone.

[0034] The addition-type organic silica gel is synergistically enhanced by the combination of polar group-containing vinyl-terminated polydimethylsiloxane, methyl hydrogen silicone oil and silane coupling agent γ-methacryloxypropyltriethoxysilane, which increases the bonding performance of the addition-type organic silica gel and improves the cohesive performance of the addition-type organic silica gel.

[0035] γ-Methacryloxypropyltriethoxysilane reacts with the trace amount of water contained in the raw materials, and is freed on the surface of the adhesive layer after hydrolysis, generating free radicals with a certain reactivity, which couples the addition-type organic silicone with the substrate during bonding, further increasing the adhesion of the addition-type organic silicone.

[0036] The above-mentioned addition-type organic silicone has strong bonding strength and a viscosity of 4000mPa·s~6000mPa·s at 25°C. Compared with traditional silicone, its viscosity is lower and it is easier to mix evenly.

[0037] As an example, the vinyl terminated polydimethylsiloxane may be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts, 100 parts,

[0038] As an example, the cross-linking agent can be 5 parts, 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, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts The amount of the cross-linking agent is preferably 5 to 30 parts.

[0039] As an example, the chain extender can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts and 30 parts, or in a range consisting of any two of the above values ​​as end values. The chain extender is preferably 10 parts to 20 parts.

[0040] As an example, the coupling agent can be 0.1 part, 0.2 part, 0.3 part, 0.4 part and 0.5 part, or in a range consisting of any two of the above values ​​as end values. The coupling agent is preferably 0.2 part to 0.5 part.

[0041] As an example, the platinum catalyst can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 1.1 part, 1.2 part, 1.3 part, 1.4 part, 1.5 part, 1.6 part, 1.7 part, 1.8 part, 1.9 part, 2 parts, 2.1 part, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3 parts, 3.1 parts, 3.2 parts, 3.3 parts, 3.4 parts, 3.5 parts, 3.6 parts, 3.7 parts, 3.8 parts, 3.9 parts, 4 parts, 4.1 parts, 4.2 parts, 1 to 2 parts, or any two of the above values ​​as end values. The platinum catalyst is preferably 0.1 to 2 parts.

[0042] As an example, the inhibitor can be 0.001 part, 0.002 part, 0.003 part, 0.004 part, 0.005 part, 0.006 part, 0.007 part, 0.008 part, 0.009 part, 0.01 part, 0.011 part, 0.012 part, 0.013 part, 0.014 part, 0.015 part, 0.016 part, 0.017 part, 0.018 part, 0.019 part, 0.02 part, or a range consisting of any two of the above values ​​as end values. The inhibitor is preferably 0.01 part to 0.02 part.

[0043] As an example, the tackifier may be 0.1 part, 0.2 part, 0.3 part, 0.4 part and 0.5 part, or in a range consisting of any two of the above values ​​as end values. The tackifier is preferably 0.1 part to 0.3 part.

[0044] The structural formula of vinyl terminated polydimethylsiloxane is as follows:

[0045]

[0046] The structural formula of the coupling agent γ-methacryloxypropyltriethoxysilane is as follows:

[0047]

[0048] The structural formula of methyl hydrogen silicone oil is as follows:

[0049]

[0050] In some embodiments, the raw materials for preparation are 50 to 90 parts by mass of the vinyl-terminated polydimethylsiloxane, 5 to 30 parts by mass of the crosslinking agent, 10 to 20 parts by mass of the chain extender, 0.2 to 0.5 parts by mass of the coupling agent, 0.1 to 2 parts by mass of the platinum catalyst, 0.01 to 0.02 parts by mass of the inhibitor, and 0.1 to 0.3 parts by mass of the tackifier. The addition-type organic silica gel with this mass ratio has better comprehensive performance, not only better adhesion, stronger adhesion and instantaneous adhesion, but also better appearance and less prone to yellowing.

[0051] In some embodiments, the degree of polymerization of the vinyl terminated polydimethylsiloxane is 200-6000.

[0052] In some embodiments, the viscosity of the vinyl-terminated polydimethylsiloxane at 25° C. is 500 mPa·s to 10,000 mPa·s. Macromolecular vinyl polysiloxanes usually have a viscosity between 6,000 mPa·s and 10,000 mPa·s, and are the basis of the addition-type organic silica gel of the present application. They can improve the adhesion of the addition-type organic silica gel and the elongation at break of the addition-type organic silica gel after curing. However, since the viscosity of macromolecular vinyl polysiloxanes is generally large, they are not easy to produce, and vinyl siloxanes with lower viscosity, i.e., vinyl siloxanes with a viscosity of 500 to 1,000 mPa·s, need to be diluted to obtain vinyl-terminated polydimethylsiloxanes with a viscosity of 500 to 10,000 mPa·s. Vinyl-terminated polydimethylsiloxane with a viscosity of 500mPa·s~10000mPa·s at 25°C is combined with a crosslinker, a chain extender, a coupling agent, a platinum catalyst, an inhibitor and a tackifier to synergistically enhance the adhesion and instantaneous adhesion of the addition-type organic silicone.

[0053] In some embodiments, the degree of polymerization of the vinyl-terminated polydimethylsiloxane is 200-6000, and the viscosity of the vinyl-terminated polydimethylsiloxane at 25° C. is 500 mPa·s-10000 mPa·s.

[0054] In some embodiments, the viscosity of the methyl hydrogen silicone oil at 25°C is 20mPa·s~50mPa·s. The hydrogen silicone oil can be compounded with methyl hydrogen silicone oils of different viscosities, preferably hydrogen silicone oils with higher viscosity, that is, hydrogen silicone oils with lower hydrogen molar content, generally with a viscosity between 300mPa·s~1000mPa·s, and low viscosity hydrogen silicone oils with a viscosity between 20mPa·s~50mPa·s, so that the viscosity of the addition type organic silica gel can be effectively controlled and the degree of cohesion of the addition type organic silica gel can be adjusted. Vinyl-terminated polydimethylsiloxane is combined with hydrogen silicone oils with a viscosity of 20mPa·s~50 mPa·s at 25°C, crosslinkers, coupling agents, platinum catalysts, inhibitors and tackifiers to synergistically enhance the adhesion and instantaneous adhesion of the addition type organic silica gel.

[0055] In some embodiments, the degree of polymerization of the methyl hydrogen silicone oil is 10-20.

[0056] In some embodiments, the tackifier may be an acryloxy-containing tackifier, rosin and its derivatives, or a polyamide resin.

[0057] In some embodiments, the tackifier is an acryloxy-containing tackifier. The acryloxy-containing tackifier can cooperate with γ-methacryloxypropyltriethoxysilane and vinyl-terminated polydimethylsiloxane to synergistically enhance the adhesion of the addition-type organic silicone; and the acryloxy-containing tackifier contains acryloxy groups, which has a strong polarity and can further improve the adhesion performance of the addition-type organic silicone.

[0058] In some embodiments, the adhesion promoter includes at least one of γ-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, methacryloxyethyltrimethylammonium chloride copolymer and γ-methacryloxypropyl-containing silicone adhesion promoter.

[0059] Furthermore, the tackifier may be UM-BX70 tackifier produced by Wuhan Enric Company.

[0060] In some embodiments, the crosslinking agent includes side-containing hydrogenated polydimethylsiloxane, the polymerization degree of the side-containing hydrogenated polydimethylsiloxane is 20-40; and / or, in the side-containing hydrogenated polydimethylsiloxane, the mass of hydrogen atoms accounts for 0.08%-1.2% of the mass of the side-containing hydrogenated polydimethylsiloxane.

[0061] In some embodiments, the inhibitor is at least one of tetramethyldivinyldisiloxane, tetramethyltetravinylcyclotetrasiloxane, 2-methyl-3-butyn-2-ol, ethynylcyclohexanol, diallyl maleate, and diisooctyl maleate.

[0062] The second aspect of the present application provides a method for preparing the addition-type organic silica gel according to the first aspect, comprising the following steps:

[0063] The vinyl-terminated polydimethylsiloxane, the cross-linking agent, the chain extender, the coupling agent, the platinum catalyst, the inhibitor and the tackifier are mixed according to the mass fractions of the raw materials to prepare a mixture;

[0064] The mixed material is subjected to a degassing treatment to obtain the addition-type organic silica gel.

[0065] In some embodiments, the mixing is performed by vacuum mixing.

[0066] In some embodiments, the ambient temperature of the mixture is 20°C to 35°C.

[0067] In some embodiments, the mixing time of the mixing is 0.5 h to 2 h, preferably 1 h to 1.5 h.

[0068] In some embodiments, the step of mixing and preparing the mixture comprises the following steps:

[0069] The platinum catalyst is first dissolved in the vinyl-terminated polydimethylsiloxane, and then the cross-linking agent, chain extender, coupling agent, inhibitor and tackifier are added to mix.

[0070] In some embodiments, the method for preparing the addition-type organic silica gel comprises the following steps:

[0071] (1) Ingredients: Weigh vinyl-terminated polydimethylsiloxane, crosslinking agent, chain extender, silane coupling agent, platinum catalyst and inhibitor according to proportion;

[0072] (2) Mixing: Add the above raw materials into a mixer respectively, stir at a certain speed under a certain vacuum degree and suitable temperature environment, filter the obtained product, and pack it into designated containers;

[0073] (3) placing in a high-speed vacuum degassing machine, degassing at a certain speed, and finally filling, and curing at high temperature after coating or filling when in use; the platinum catalyst should first be dissolved in vinyl-terminated polydimethylsiloxane of appropriate viscosity.

[0074] The third aspect of the present application provides a use of the addition-type organic silica gel as described in the first aspect in the preparation of electronic devices.

[0075] The above-mentioned addition-type organic silicone can be used for bonding components, packaging chips, sealing and moisture-proofing in electronic devices, etc.

[0076] The fourth aspect of the present application provides an electronic device, comprising the addition-type organic silica gel as described in the first aspect, or the addition-type organic silica gel prepared by the preparation method of the addition-type organic silica gel as described in the second aspect.

[0077] The above-mentioned electronic devices include, but are not limited to, solar cell modules, solar lamps, mobile phones, computers, televisions, refrigerators, air conditioners, automotive electronic devices, PC display panels, vehicle-mounted display screens and mobile phone display screens.

[0078] When the above-mentioned addition-type organic silicone is used as an adhesive or packaging adhesive in a display screen, the addition-type organic silicone can be used for a long time in the range of -30~200℃, which can improve the reliability of the display screen and thus extend the service life of the display screen product. Its good optical transparency has a high transmittance to visible light and will not reduce the brightness and color saturation of the display screen, making the image presented to the user clearer and more vivid.

[0079] The following are specific embodiments.

[0080] Example 1

[0081] (1) 85 parts by weight of vinyl-terminated polydimethylsiloxane with a degree of polymerization of 200, 5 parts by weight of a cross-linking agent with a degree of polymerization of 20, 10 parts by weight of a chain extender with a degree of polymerization of 20, 0.5 parts by weight of a silane coupling agent, 0.1 parts by weight of a tackifier, 0.2 parts by weight of a platinum catalyst, and 0.01 parts of an inhibitor.

[0082] (2) Ingredients: Weigh vinyl-terminated polydimethylsiloxane, cross-linking agent, chain extender, silane coupling agent, tackifier, platinum catalyst and inhibitor according to proportion;

[0083] (3) Mixing: Add the above raw materials into a blender respectively, stir at a speed of 800 r / min for 1.5 h under a vacuum degree of -0.095 MPa and a temperature of 25°C. Filter the obtained product and dispense it into designated containers;

[0084] (4) Place in a high-speed vacuum degassing machine and degas at a speed of 1500 r / min, and finally fill. When in use, place in a 70°C environment for curing after coating or potting. The curing performance is shown in Table 1.

[0085] Among them, the vinyl-terminated polydimethylsiloxane with a viscosity of 500mPa·s~10000mPa·s at 25°C is compounded with 15 parts by mass of RH-Vi303 with a viscosity of 10000mPa·s, 40 parts by mass of RH-Vi305 with a viscosity of 1000mPa·s and 30 parts by mass of RH-Vi311 with a viscosity of 500mPa·s (RH-Vi303, RH-Vi305 and RH-Vi311 are all from Runhe Materials).

[0086] The cross-linking agent used was TJ-013HD (TJ-013HD from Tianjiang High-tech Materials) with a viscosity of 30 mPa·s.

[0087] Chain extender with a viscosity of 20mPa·s~50 mPa·s at 25°C: compounded with 3.5 parts by mass of RH-H45 with a viscosity of 20mPa·s and 6.5 parts by mass of RH-DH07 with a viscosity of 50mPa·s (RH-H45 and RH-DH07 are both from Runhe Materials).

[0088] The platinum catalyst uses trimethyl(methylcyclopentadienyl)platinum.

[0089] The inhibitor used was diallyl maleate.

[0090] The coupling agent used was KH-571.

[0091] The tackifier used was UM-BX70 produced by Wuhan Enric Company.

[0092] Example 2

[0093] (1) 50 parts by mass of vinyl-terminated polydimethylsiloxane with a degree of polymerization of 400, 20 parts by mass of a cross-linking agent with a degree of polymerization of 40, 20 parts by mass of a chain extender with a degree of polymerization of 10, 0.5 parts by mass of a silane coupling agent, 0.2 parts by mass of a tackifier, 0.01 parts by mass of an inhibitor, and 0.1 parts of a platinum catalyst.

[0094] (2) Ingredients: Weigh vinyl-terminated polydimethylsiloxane, cross-linking agent, chain extender, silane coupling agent, tackifier, platinum catalyst and inhibitor according to proportion;

[0095] (3) Mixing: Add the above raw materials into a blender respectively, stir at a speed of 700 r / min for 1.0 h under a vacuum degree of -0.052 MPa and a temperature of 20-35°C. Filter the obtained product and pack it into designated containers in the dark.

[0096] (4) Place in a high-speed vacuum degassing machine and degas at a speed of 1500 r / min, and finally fill. When in use, place in a 70°C environment for curing after coating or potting. The curing performance is shown in Table 1.

[0097] Among them, the vinyl-terminated polydimethylsiloxane with a viscosity of 500mPa·s~10000mPa·s at 25°C is compounded with 20 parts by mass of RH-Vi303 with a viscosity of 10000mPa·s, 15 parts by mass of RH-Vi305 with a viscosity of 1000mPa·s and 5 parts by mass of RH-Vi311 with a viscosity of 500mPa·s (RH-Vi303, RH-Vi305 and RH-Vi311 are all from Runhe Materials).

[0098] The cross-linking agent used was TJ-013HD (TJ-013HD from Tianjiang High-tech Materials) with a viscosity of 30 mPa·s.

[0099] Chain extender with a viscosity of 20mPa·s~50mPa·s at 25°C: compounded with 6 parts by mass of RH-H45 with a viscosity of 20mPa·s and 14 parts by mass of RH-DH07 with a viscosity of 50mPa·s (RH-H45 and RH-DH07 are both from Runhe Materials).

[0100] The platinum catalyst is trimethyl(methylcyclopentadienyl)platinum.

[0101] The inhibitor is diallyl maleate and the coupling agent is KH-571.

[0102] The tackifier used was UM-BX70 produced by Wuhan Enric Company.

[0103] Example 3

[0104] Example 3 is substantially the same as Example 1, except that the coupling agent is 0.1 parts by weight.

[0105] Example 4

[0106] Example 4 is substantially the same as Example 1, except that the amount of the tackifier is 0.5 parts by mass.

[0107] Example 5

[0108] Example 5 is substantially the same as Example 1, except that the amount of the vinyl-terminated polydimethylsiloxane is 20 parts by mass.

[0109] Example 6

[0110] Example 6 is basically the same as Example 1, except that the tackifier uses rosin of equal mass.

[0111] Comparative Example 1

[0112] Comparative Example 1 is substantially the same as Example 1, except that the tackifier is omitted.

[0113] Comparative Example 2

[0114] Comparative Example 2 is substantially the same as Example 1, except that the coupling agent is omitted.

[0115] Comparative Example 3

[0116] Comparative Example 3 is substantially the same as Example 1, except that an equal amount of titanate coupling agent is used to replace KH-571.

[0117] The performance of the addition-type organic silica gels prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was tested, and the test results are shown in Table 1 below.

[0118] Among them, the test conditions or test standards for each performance test item are:

[0119] The transmittance test standard is JIS K7105-81;

[0120] The volume shrinkage test standard is ASTM C1241-14;

[0121] The haze test standard is JIS K 7136;

[0122] The tensile strength test standard is JIS K 6815-1;

[0123] The peel strength test standard is GB / T 2792-2014.

[0124] Table 1

[0125]

[0126] As can be seen from Table 1 above, Examples 1 to 6 interact with each other through a specific mass ratio of vinyl-terminated polydimethylsiloxane, methyl hydrogen silicone oil, crosslinking agent, coupling agent, platinum catalyst, inhibitor and tackifier, and synergistically enhance the effect, so that the tensile strength and peel strength of the addition-type organic silica gel are high, and the adhesion of the addition-type organic silica gel is improved; and the adhesion is not easy to decrease rapidly over time, and a high peel strength can be reached within 20 minutes, which improves the instantaneous adhesion and can be quickly bonded; in addition, the addition-type organic silica gel prepared in Examples 1 to 6 not only has good adhesion, but also has high transmittance, good appearance transparency, and is not easy to produce yellowing. The tensile strength and peel strength of Comparative Examples 1 to 2 are both lower than those of the embodiments of the present application, indicating that omitting any component of the coupling agent and the tackifier cannot achieve the technical effect of the present application. The instantaneous peel strength and 24-hour peel strength of the organic silica gel prepared by Comparative Example 3 using titanate as a coupling agent are not as good as those of the present application.

[0127] In addition, when the tackifier is an acryloxy-containing tackifier, the improvement in the adhesion of the addition-type silicone is particularly significant.

[0128] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An addition-type organic silica gel, characterized in that: The raw materials for preparing the addition-type organic silica gel include the following components in parts by weight: 20 to 90 parts of vinyl-terminated polydimethylsiloxane, 5 to 55 parts of a cross-linking agent, 10 to 30 parts of a chain extender, 0.1 to 0.5 parts of a coupling agent, 0.1 to 5 parts of a platinum catalyst, 0.001 to 0.02 parts of an inhibitor, and 0.1 to 0.5 parts of a tackifier; The chain extender includes methyl hydrogen silicone oil; The coupling agent includes γ-methacryloxypropyltriethoxysilane.

2. The addition-type organic silica gel according to claim 1, characterized in that: In the raw materials for preparation, the vinyl-terminated polydimethylsiloxane is 50 to 90 parts by weight; the cross-linking agent is 5 to 30 parts; and the chain extender is 10 to 20 parts. The coupling agent is 0.2 to 0.5 parts; the platinum catalyst is 0.1 to 2 parts; the inhibitor is 0.01 to 0.02 parts; and the tackifier is 0.1 to 0.3 parts.

3. The addition-type organic silica gel according to claim 1, characterized in that: The degree of polymerization of the vinyl-terminated polydimethylsiloxane is 200-6000; and / or the viscosity of the vinyl-terminated polydimethylsiloxane at 25° C. is 500 mPa·s-10000 mPa·s.

4. The addition-type organic silica gel according to claim 1, characterized in that: The viscosity of the methyl hydrogen silicone oil at 25° C. is 20 mPa·s to 50 mPa·s.

5. The addition-type organic silica gel according to any one of claims 1 to 4, characterized in that: The tackifier is an acryloxy-containing tackifier; Optionally, the adhesion promoter includes at least one of γ-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, methacryloxyethyltrimethylammonium chloride copolymer and γ-methacryloxypropyl-containing organic silicon adhesion promoter.

6. The addition-type organic silica gel according to any one of claims 1 to 4, characterized in that: At least one of the following conditions is met: (1) The crosslinking agent comprises a side-containing hydrogenated polydimethylsiloxane, wherein the degree of polymerization of the side-containing hydrogenated polydimethylsiloxane is 20 to 40; and / or, in the side-containing hydrogenated polydimethylsiloxane, the mass of hydrogen atoms accounts for 0.08% to 1.2% of the mass of the side-containing hydrogenated polydimethylsiloxane; (2) The inhibitor is at least one of tetramethyldivinyldisiloxane, tetramethyltetravinylcyclotetrasiloxane, 2-methyl-3-butyn-2-ol, ethynylcyclohexanol, diallyl maleate and diisooctyl maleate.

7. A method for preparing an addition-type organic silica gel according to any one of claims 1 to 6, characterized in that: The steps include: The vinyl-terminated polydimethylsiloxane, the cross-linking agent, the chain extender, the coupling agent, the platinum catalyst, the inhibitor and the tackifier are mixed according to the mass fractions of the raw materials to prepare a mixture; The mixed material is subjected to a degassing treatment to obtain the addition-type organic silica gel.

8. The method for preparing addition-type organic silica gel according to claim 7, characterized in that: The mixture satisfies at least one of the following conditions: (1) The mixing is performed by vacuum mixing; (2) The ambient temperature of the mixing material is 20°C to 35°C; (3) The mixing time of the mixing is 0.5h~2h; (4) The step of preparing the mixed material comprises the following steps: The platinum catalyst is first dissolved in the vinyl-terminated polydimethylsiloxane, and then the cross-linking agent, chain extender, coupling agent, inhibitor and tackifier are added to mix.

9. Use of the addition-type organic silica gel according to any one of claims 1 to 6 in the preparation of electronic devices.

10. An electronic device, characterized in that: The invention comprises the addition type organic silica gel as described in any one of claims 1 to 6, or the addition type organic silica gel prepared by the preparation method of the addition type organic silica gel as described in any one of claims 7 to 8.

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