Two-component organosilicon composition, organosilicon rubber, preparation method and application

Abstract

The present invention relates to a two-component organosilicon composition, comprising component A and component B, wherein: by weight parts, component A contains the following components: 30 to 60 parts of a first vinyl polysiloxane, 1 to 5 parts of a second vinyl polysiloxane, 1 to 3 parts of a first silicon hydride group-containing polysiloxane, and 0.5 to 1.5 parts of a second silicon hydride group-containing polysiloxane; component B contains the following components: 20 to 40 parts of a first vinyl polysiloxane, 2 to 4 parts of a vinyl MQ silicone resin, and 0.03 to 0.08 parts of a photocatalyst; the first vinyl polysiloxane is a vinyl-terminated polysiloxane; the second vinyl polysiloxane is a vinyl-monoterminated polysiloxane, the MQ silicone resin is an organosilicon resin composed of monofunctional siloxane linkages and tetrafunctional siloxane linkages, and the MQ silicone resin contains vinyl; the weight ratio of component A to component B is (8 to 12):1. This organosilicon has good aging resistance, yellowing resistance, and good toughness, with a simple composition and is applicable to the encapsulation of semiconductor devices.

Description

Technical Field

[0001] The present invention relates to the technical field of silicone rubber, and particularly to a two-component silicone rubber composition, a silicone rubber, a preparation method and an application thereof Background Art

[0002] With the development of semiconductor display technology, the requirements for the weather resistance of bonding materials are getting higher and higher. In addition to having good transparency and adhesiveness, they also need to be able to adapt to high-intensity light and high heat dissipation temperatures of semiconductor devices. The reliability of traditional silicone rubber in maintaining transparency, yellowing resistance, aging resistance and non-deformation for a long time can no longer meet the application requirements Summary of the Invention

[0003] Based on this, the objectives of the present invention include providing a two-component silicone rubber composition. The silicone rubber prepared therefrom has a suitable crosslinking degree, a low residual double bond content, good aging resistance, yellowing resistance and toughness, and can be applied to semiconductor device packaging. The present invention also provides a silicone rubber, a preparation method and an application thereof

[0004] In the first aspect of the present application, a two-component silicone rubber composition is provided, including component A and component B, wherein:

[0005] By weight, component A contains the following components: 30-60 parts of a first vinyl polysiloxane, 1-5 parts of a second vinyl polysiloxane, 1-3 parts of a first silicon hydride group-containing polysiloxane and 0.5-1.5 parts of a second silicon hydride group-containing polysiloxane

[0006] By weight, component B contains the following components: 20-40 parts of the first vinyl polysiloxane, 2-4 parts of vinyl MQ silicone resin and 0.03-0.08 parts of a photocatalyst

[0007] The first vinyl polysiloxane is a vinyl double-capped polysiloxane

[0008] The second vinyl polysiloxane is a vinyl single-capped polysiloxane

[0009] The MQ silicone resin is a silicone resin composed of monofunctional siloxane linkages and tetrafunctional siloxane linkages, and the MQ silicone resin contains vinyl

[0010] The weight ratio of component A to component B is (8-12):1

[0011] In some embodiments, in the two-component silicone rubber composition, one or more of the following characteristics are satisfied:

[0012] The structural formula of the first vinyl polysiloxane is Among them, R1 to R4 are each independently C 1-6 alkyl; m is an integer selected from 360 to 700 or the vinyl content is 0.05%-0.10%;

[0013] The structural formula of the second vinyl polysiloxane is Among them, R5 to R9 are each independently C 1-6 alkyl; n is an integer selected from 140 to 240 or the vinyl content is 0.15%-0.25%;

[0014] The structural formula of the first hydrosilyl-functional polysiloxane is Among them, R 10 is H or C 1-6 alkyl, R 11 ~R 14 are each independently C 1-6 alkyl; p is an integer selected from 2 to 10 or the hydrosilyl content is 0.16% to 0.24%;

[0015] The structural formula of the second hydrosilyl-functional polysiloxane is Among them, R 15 ~R 23 are each independently C 1-6 alkyl, x is an integer selected from 10 to 20; y is an integer selected from 8 to 24 or the hydrosilyl content is 0.5% to 0.8%;

[0016] In the MQ silicone resin, the ratio of the number of monofunctional siloxane linkages to the number of tetrafunctional siloxane linkages is 0.5 to 1.2;

[0017] The vinyl content in the MQ silicone resin is 3% to 6%.

[0018] In some embodiments, in the two-component silicone rubber composition, the structural formula of the MQ silicone resin is [R d R e R f SiO 0.5 a [SiO2] b wherein at least one of R d , R e , R f is vinyl; a / b = 0.5 to 1.2 or the vinyl content is 3% to 6%.

[0019] In some embodiments, in the two-component silicone rubber composition, one or more of the following characteristics are satisfied:

[0020] The viscosity of the first vinyl polysiloxane is 60000 cps to 100000 cps;​

[0021] The viscosity of the second vinyl polysiloxane is 2,000 cps - 5,000 cps;

[0022] In some embodiments, in the two-component silicone rubber composition, the catalyst is a platinum complex, and the platinum complex is selected from β-diketone complexes, (η-cyclopentadienyl)tris(α-aliphatic)platinum complexes, and C1-C 20 One of the (η-5-cyclopentadienyl)tris(α-aliphatic)platinum complexes substituted with aliphatic groups.

[0023] In some embodiments, in the two-component silicone rubber composition, one or more of the following characteristics are satisfied:

[0024] The weight ratio of the first vinyl polysiloxane to the second vinyl polysiloxane is (500 - 2,500):1;

[0025] The weight ratio of the first silicon hydride group-containing polysiloxane to the second silicon hydride group-containing polysiloxane is (2 - 4):1;

[0026] The weight ratio of the vinyl MQ silicone resin to the sum of the weights of the first vinyl polysiloxane and the second vinyl polysiloxane is (0.001 - 0.01):1;

[0027] The weight ratio of the sum of the weights of the first silicon hydride group-containing polysiloxane and the second silicon hydride group-containing polysiloxane to the sum of the weights of the first vinyl polysiloxane and the second vinyl polysiloxane is (0.1 - 0.2):1.

[0028] In the second aspect of the present application, a method for preparing a silicone rubber is provided, including the following steps:

[0029] According to the two-component silicone rubber composition described in the first aspect, provide component A and component B;

[0030] Use the component A and the component B to prepare mixed rubber A and mixed rubber B respectively; wherein, mix the first vinyl polysiloxane, the first vinyl polysiloxane, the first silicon hydride group-containing polysiloxane, and the second silicon hydride group-containing polysiloxane in the component A, and defoam to obtain mixed rubber A; mix the first vinyl polysiloxane and the vinyl MQ silicone resin in the component B, defoam, and then add a photocatalyst and continue to mix and defoam to obtain mixed rubber B;

[0031] Mix the mixed rubber A and the mixed rubber B according to a weight ratio of (8 - 12):1, and cure by ultraviolet light to obtain a silicone rubber.

[0032] In some embodiments, in the preparation method, one or more of the following features are satisfied:

[0033] In the step of mixing the raw materials in the component A, the mixing time is 2 min to 4 min;

[0034] In the step of mixing the raw materials in the component A, the mixing temperature is 25°C ± 1°C;

[0035] In the step of mixing and defoaming the raw materials in the component A, the defoaming time is 1 min to 2 min;

[0036] In the step of mixing and defoaming the raw materials in the component A, the defoaming temperature is 25°C ± 1°C;

[0037] In the step of mixing the raw materials in the component B, the mixing time is 2 min to 4 min;

[0038] In the step of mixing the raw materials in the component B, the mixing temperature is 25°C ± 1°C;

[0039] In the step of mixing and defoaming the raw materials in the component B, the defoaming time is 1 min to 2 min;

[0040] In the step of mixing and defoaming the raw materials in the component B, the defoaming temperature is 25°C ± 1°C;

[0041] The wavelength of the ultraviolet light for the ultraviolet curing is 320 nm to 420 nm;

[0042] The time for the ultraviolet curing is 1 min to 3 min;

[0043] The temperature for the ultraviolet curing is 25°C ± 1°C.

[0044] In the third aspect of the present application, an organosilica gel is provided, which is prepared according to the preparation method described in the second aspect.

[0045] In the fourth aspect of the present application, an application of the two-component organosilica gel composition described in the first aspect, the organosilica gel prepared by the organosilica gel described in the third aspect or the preparation method described in the second aspect in LED packaging, semiconductor manufacturing or transparent product assembly is provided.

[0046] Using a vinyl mono-capped polysiloxane and a vinyl di-capped polysiloxane together as prepolymers, a hydrosilyl-containing polysiloxane as a crosslinking agent, and introducing a vinyl MQ silicone resin, the raw material system of this two-component silicone rubber composition has a high reaction activity of the hydrosilyl groups, a small amount of catalyst, and a high reaction rate, which is beneficial to obtaining a silicone rubber product with a suitable crosslinking degree; the introduced MQ resin can be mixed and dispersed in the silicone rubber with the polymer system, thereby playing a better strengthening and cohesion role, helping to obtain a silicone rubber with better aging resistance, yellowing resistance and better toughness, with a simple composition and being applicable to the encapsulation of semiconductor devices. Detailed implementation manners

[0047] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0049] The term

[0050] "Silicon-containing hydrocarbon group" in this application refers to a monovalent residue formed by removing one hydrogen atom from a hydrocarbon substance containing a silicon atom as a backbone atom, which contains a primary (n) carbon / silicon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof.

[0051] "Alkyl" refers to a monovalent residue formed by removing a hydrogen atom from a saturated hydrocarbon containing primary (normal) carbon atoms, or secondary carbon atoms, or tertiary carbon atoms, or quaternary carbon atoms, or a combination thereof. Phrases containing this term, for example, "C1-C6 alkyl" refer to alkyl groups containing 1 to 6 carbon atoms, and each occurrence can independently be a C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl or C6 alkyl. Suitable examples include but are not limited to: ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl (-CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2) and 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3).

[0052] Polysiloxanes, including linear polysiloxanes and branched polysiloxanes, and some polysiloxanes remain liquid at room temperature. The polysiloxanes described in this application are polysiloxanes that remain liquid at room temperature and can also be called silicone oils.

[0053] MQ silicone resin refers to a kind of silicone resin composed of monofunctional Si-O units (also denoted as M units or "mono" units) and tetrafunctional Si-O units (also denoted as Q units or "quad" units). It has a double-layer structure of closely packed spheres.

[0054] Viscosity, also known as viscous force, is a physical property parameter used to measure the magnitude of viscous force. When a fluid flows, the relative motion between adjacent fluid layers generates frictional resistance between the layers, and the viscosity of the liquid can be measured with a viscometer. In this application, the viscosity of the glue is measured with a cone-plate viscometer of model DVNXHBCP, and the unit is cps. In the present invention, unless otherwise specified, the viscosity test temperature is room temperature, for example, it can be 25°C ± 5°C.

[0055] Vinyl polyorganosiloxane, which remains liquid at room temperature and is also called vinyl silicone oil, refers to a polyorganosiloxane containing vinyl groups. The backbone of the vinyl polyorganosiloxane in this application, that is, the repeating unit [SiRR’-O], is a linear structure, where both R and R’ are hydrocarbon groups, and R and R’ can be the same or different.

[0056] Vinyl mono-terminated polyorganosiloxane, which remains liquid at room temperature and is also called vinyl mono-terminated silicone oil, refers to a polyorganosiloxane in which one end of the repeating unit [SiRR’-O] of the backbone is terminated by a vinyl group, where both R and R’ are hydrocarbon groups, and R and R’ can be the same or different.

[0057] Vinyl di-terminated polyorganosiloxane, which remains liquid at room temperature and is also called vinyl di-terminated silicone oil, refers to a polyorganosiloxane in which both ends of the repeating unit [SiRR’-O] of the backbone are terminated by vinyl groups, where both R and R’ are hydrocarbon groups, and R and R’ can be the same or different.

[0058] Vinyl content refers to the vinyl content in vinyl polyorganosiloxane or MQ silicone resin containing vinyl groups, which can be expressed in mmol / g or wt%. In this application, unless otherwise specified, the calculation method is the mass ratio of vinyl chain segments in the silicone resin to the polyorganosiloxane or vinyl MQ silicone resin, and the unit is %.

[0059] Hydrogen-containing polyorganosiloxane, also known as hydrogen-containing polysiloxane or hydrogen-containing silicone oil, refers to a polyorganosiloxane with hydrogen atoms attached to silicon.

[0060] Hydrogen content refers to the hydrogen content in hydrogen-containing polyorganosiloxane, which can be expressed in mmol / g or wt%. In this application, the calculation method is the mass ratio of hydrogen atoms bonded to silicon in the polyorganosiloxane to the polyorganosiloxane, and the unit is %.

[0061] Organic silicone rubbers are widely used in the packaging process of semiconductor devices due to their high transparency and low thermal shrinkage characteristics. However, traditional organic silicone rubbers have low curing efficiency, requiring long reaction times, high curing temperatures, or the addition of large amounts of precious metal catalysts. On the one hand, this results in cumbersome processes and low production efficiency. On the other hand, the cured organic silicone rubbers have poor aging resistance, toughness, and brittleness, and generally require the addition of inhibitors, additives, etc. However, the introduction of additives not only makes the production process more complicated, but also most of the additives are benzene series substances, which cause greater environmental pollution.

[0062] After extensive exploration, a two-component organic silicone rubber composition, preparation method, and organic silicone rubber were found, which can better overcome the above problems. The two-component organic silicone rubber composition has a short curing time when applied, and has good aging resistance, yellowing resistance, and toughness.

[0063] In the first aspect of the present application, a two-component organic silicone rubber composition is provided, including component A and component B, wherein:

[0064] Based on parts by weight, the component A contains the following components: 30-60 parts of a first vinyl polysiloxane, 1-5 parts of a second vinyl polysiloxane, 1-3 parts of a first silicon hydride group-containing polysiloxane, and 0.5-1.5 parts of a second silicon hydride group-containing polysiloxane;

[0065] Based on parts by weight, the component B contains the following components: 20-40 parts of the first vinyl polysiloxane, 2-4 parts of vinyl MQ silicone resin, and 0.03-0.08 parts of a photocatalyst;

[0066] The first vinyl polysiloxane is a vinyl double-terminated polysiloxane;

[0067] The second vinyl polysiloxane is a vinyl single-terminated polysiloxane;

[0068] The MQ silicone resin is an organosilicon resin composed of monofunctional siloxane linkages and tetrafunctional siloxane linkages, and the MQ silicone resin contains vinyl;

[0069] The weight ratio of the component A to the component B is (8-12):1.

[0070] Using vinyl mono - terminated polysiloxane and vinyl di - terminated polysiloxane together as prepolymers, a polysiloxane containing silicon - hydrogen as a cross - linker, and introducing an MQ silicone resin containing vinyl, the raw material system of this two - component silicone rubber composition has a high reaction activity of silicon - hydrogen groups, a small amount of catalyst, and a high reaction rate, which is beneficial to obtaining a silicone rubber product with a suitable cross - linking degree; the introduced MQ resin can be mixed and dispersed in the polymer system in the silicone rubber, thus playing a good strengthening and cohesive role, helping to obtain a silicone rubber with better aging resistance, yellowing resistance and better toughness. The composition is simple and can be applied to the encapsulation of semiconductor devices.

[0071] Both component A and component B contain a first vinyl polysiloxane (vinyl di - terminated polysiloxane). The vinyl di - terminated polysiloxane is the main component of the silicone rubber composition system, providing vinyl groups. Both ends can undergo addition reactions with polysiloxanes containing silicon - hydrogen groups, thereby forming a polymer with a certain cross - linking degree / gel degree, which is beneficial to increasing the reaction rate of silicone rubber preparation and improving the toughness of the prepared silicone rubber.

[0072] Controlling the content of the first vinyl polysiloxane in component A within a suitable range is beneficial to improving the production efficiency in the preparation process of silicone rubber using the composition. If the content of the first vinyl polysiloxane in component A is lower than the suitable range, it may result in a lower vinyl content in component A. After mixing the raw materials in component A, the degree of preliminary reaction and cross - linking between vinyl polysiloxane and polysiloxane containing silicon - hydrogen groups is lower. As a result, the reaction rate of the cross - linking reaction is slower or the monomer residue amount is larger during the preparation process of silicone rubber, and the performance of the prepared silicone rubber is poor; if the content of the first vinyl polysiloxane in component A is higher than the suitable range, it may lead to a smaller proportion of other components such as polysiloxane containing silicon - hydrogen groups when used as raw materials for silicone rubber preparation, a smaller overall cross - linking degree and a lower gel content in the system, ultimately resulting in a weaker colloid strength and a larger penetration.

[0073] In some embodiments, in the two - component silicone rubber composition, by weight, the first vinyl polysiloxane in component A is 30 - 60 parts, further can be 32 - 60 parts, still further can be 34 - 60 parts, and can also be selected from the following one - part number or an interval composed of two: 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts, 50 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, etc.

[0074] In some embodiments, in the two-component organosilicon rubber composition, based on parts by weight, the first vinyl polysiloxane in component B is 20 to 40 parts, further can be 20 to 35 parts, still further can be 20 to 30 parts, and can also be selected from the following one part or the interval composed of two 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.

[0075] In some embodiments, in the two-component organosilicon rubber composition, based on parts by weight, the first vinyl polysiloxanes in component A and component B are 30 to 60 parts and 20 to 40 parts respectively, further can be 32 to 60 parts and 20 to 35 parts, still further can be 34 to 60 parts and 20 to 30 parts.

[0076] The second vinyl polysiloxane (i.e., vinyl-terminated polysiloxane) can undergo an addition reaction with the silicon hydride group-containing polysiloxane to form comb-shaped branched chains on the backbone of the silicon hydride group-containing polysiloxane. The comb-shaped branched chains have a certain chain segment flexibility, which helps to balance the rigidity and toughness of the cured product.

[0077] Controlling the content of the second vinyl polysiloxane in component A within a suitable range is beneficial to improving the tensile properties of the prepared organosilicon rubber. If the content of the second vinyl polysiloxane in component A is lower than the suitable range, it may cause a relatively small proportion of the siloxane branched chains in the polymer, and further cause the organosilicon rubber to have greater hardness and brittleness; if the content of the second vinyl polysiloxane in component A is higher than the suitable range, it may lead to insufficient reaction of the monomers and intermediate components in the organosilicon oil prepared from component A and component B, and the appearance of an oily substance on the surface after standing, affecting the adhesion.

[0078] In some embodiments, in the two-component organosilicon rubber composition, based on parts by weight, the content of the second vinyl polysiloxane in component A is 1 to 5 parts, further can be 1 to 4 parts, still further can be 2 to 4 parts, and can also be selected from the following one part or the interval composed of two parts: 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0079] In some embodiments, in the two-component organosilicon rubber composition, based on parts by weight, the content of the first silicon hydride group-containing polysiloxane in component A is 1 to 3 parts, further can be 1.5 to 3 parts, still further can be 2 to 3 parts, and can also be selected from the following one part or the interval composed of two parts: 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0080] Controlling the content of the second silicon hydride group-containing polysiloxane in Component A within a suitable range is beneficial to obtaining an organosilica gel with appropriate hardness, toughness, and penetration. If the content of the second silicon hydride group-containing polysiloxane in Component A is lower than the suitable range, it may result in a relatively small content of oligomers with a comb-like (or branched structure) formed during the preparation process, and thus the gel content in the obtained organosilica gel is relatively low, manifested as the organosilica gel being softer or having a smaller penetration; if the content of the second silicon hydride group-containing polysiloxane in Component A is higher than the suitable range, it may lead to a relatively high gel content in the obtained organosilica gel, ultimately resulting in the organosilica gel being harder, having poor yellowing resistance, etc.

[0081] In some embodiments, in the two-component organosilica gel composition, based on parts by weight, the content of the second silicon hydride group-containing polysiloxane in Component A is 0.5 to 1.5 parts, further can be 1.5 to 1 part, still further can be 0.7 to 1 part, and can also be selected from the following intervals composed of one or two of the following parts: 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1.0 part, 1.1 part, 1.2 part, 1.3 part, 1.4 part, 1.5 part, etc.

[0082] The functions of MQ silicone resin include reinforcing the mechanical properties of rubber, improving heat resistance, cold resistance, etc. Controlling the content of MQ silicone resin in Component B within a suitable range is beneficial to preparing an organosilica gel with better aging resistance. If the content of MQ silicone resin in Component B is lower than the suitable range, it may cause the reinforcing effect on the prepared organosilica gel to be prior, and the obtained organosilica gel is more brittle and prone to cracks at high temperatures; if the content of MQ silicone resin in Component B is higher than the suitable range, it may lead to the prepared organosilica gel being softer, and at the same time, it may cause the vinyl content in the preparation system to be too high, and thus an oily substance appears on the surface of the obtained organosilica gel after standing.

[0083] In some embodiments, in the two-component organosilica gel composition, based on parts by weight, the content of MQ silicone resin in Component B is 2 to 4 parts, further can be 2 to 3.5 parts, still further can be 2 to 2.5 parts, and can also be selected from the following intervals composed of one or two of the following parts: 2 parts, 2.2 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.8 parts, 3.0 parts, 3.2 parts, 3.4 parts, 3.5 parts, 3.6 parts, 3.8 parts, 4.0 parts, etc.

[0084] In some embodiments, in the two-component organosilica gel composition, the structural formula of the first vinyl polysiloxane is wherein, R1 to R4 are each independently C 1-6 alkyl.

[0085] In the structural formula of the first vinyl polysiloxane, the number of repeating units of [SiR1R1-O] affects the comprehensive mechanical properties of the prepared silicone rubber. If the number of repeating units of [SiR1R1-O] in the structural formula of the first vinyl polysiloxane is less than the appropriate range, it may cause the crosslinked structure to be loose, resulting in a lower gel content and poorer toughness after the two-component silicone rubber composition reacts and cures; if the number of repeating units of [SiR1R1-O] in the structural formula of the first vinyl polysiloxane is greater than the appropriate range, it may also cause the crosslinked structure to be loose, resulting in a lower gel content and deteriorated toughness after the two-component silicone rubber composition reacts and cures.

[0086] In some embodiments, in the structure of the first vinyl polysiloxane, m is an integer selected from 360 to 700, further can be an integer selected from 400 - 700, still further can be an integer selected from 430 - 700, and can also be one of the following integers or an interval composed of two: 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600, 620, 640, 660, 680 or 700.

[0087] In some embodiments, in the structure of the first vinyl polysiloxane, the vinyl content is 0.05% - 0.10%, further can be 0.06% - 0.10%, still further can be 0.07 - 0.10%.

[0088] In this application, the calculation method of the vinyl content is the mass ratio of the vinyl link in the polysiloxane or MQ silicone resin containing vinyl to the polymer, with the unit of %. For example, CH2=CH-[-Si(CH3)2-O-] m -Si(CH3)2-CH=CH2, when m is 360, the calculated vinyl content is 54 / (78*360 + 112) = 0.19%.

[0089] In some embodiments, in the two-component silicone rubber composition, the first vinyl poly

[0090] siloxane has a structural formula of wherein, R1 to R4 are each independently a C 1-6 alkyl group, m is an integer selected from 360 to 700 or the vinyl content is 0.05% - 0.10%.

[0091] In some embodiments, in the structure of the first vinyl polysiloxane, R1 and R2 are both methyl groups.

[0092] In some embodiments, in the structure of the first vinyl polysiloxane, R1 to R4 are all methyl groups.

[0093] In some embodiments, in the two-component organosilicon rubber composition, the second vinyl polysiloxane

[0094] has the structural formula wherein, R5 to R9 are each independently a C 1-6 alkyl group.

[0095] The number of repeating units of the structural formula [SiR6R6-O] of the second vinyl polysiloxane also affects the comprehensive mechanical properties of the prepared organosilicon rubber. If the number of repeating units of [SiR1R1-O] in the structural formula of the second vinyl polysiloxane is less than the appropriate range, the chain length of the comb-like side chains in the cured product of the composition may be small, and the contribution to the flexibility of the product may be small; if the number of repeating units of [SiR1R1-O] in the structural formula of the second vinyl polysiloxane is greater than the appropriate range, the structure of the product may be loose.

[0096] In some embodiments, in the structure of the second vinyl polysiloxane, n is an integer selected from 140 to 240, further can be an integer selected from 160 - 240, still further can be an integer selected from 190 - 240, and can also be one of the following integers or an interval composed of two: 140, 150, 160, 170, 180, 190, 200, 210, 220, 230 or 240.

[0097] In some embodiments, in the structure of the second vinyl polysiloxane, the vinyl content is 0.15% - 0.25%, further can be 0.17% - 0.25%, still further can be 0.19% - 0.25%.

[0098] In some embodiments, in the two-component organosilicon rubber composition, the second vinyl polysiloxane has the structural formula wherein, R5 to R9 are each independently a C 1-6 alkyl group, n is an integer selected from 140 to 240 or the vinyl content is 0.15 - 0.25%.

[0099] In some embodiments, in the structure of the second vinyl polysiloxane, R6 and R7 are both methyl groups.

[0100] In some embodiments, in the structure of the second vinyl polysiloxane, R5 to R9 are all methyl groups.

[0101] In some embodiments, in the two-component organosilicon rubber composition, the first silicon hydride group-containing polysiloxane has the structural formula wherein, R 10 is H or C 1-6 alkyl group, R 11 to R 14 are each independently C1-6 Alkyl group.

[0102] R 10 When R is H, the second polysiloxane containing silicon hydride groups contains two silicon hydride groups. At this time, both ends of the chain segment of the first polysiloxane containing silicon hydride groups can provide silicon hydride groups for addition reaction with vinyl groups, which helps to improve the crosslinking level of the cured product.

[0103] Through experiments, the applicant also found that in the structure of the first polysiloxane containing silicon hydride groups, the number of repeating units of [SiR 13 R 14 -O] has a significant effect on improving the comprehensive mechanical properties of the prepared silicone rubber.

[0104] In some embodiments, in the structure of the first polysiloxane containing silicon hydride groups, p is an integer selected from 2 to 10, further can be an integer selected from 4 to 10, still further can be an integer selected from 4 to 8, and can also be one of the following integers or an interval composed of two: 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0105] In some embodiments, in the structure of the first polysiloxane containing silicon hydride groups, the silicon hydride content is 0.16% - 0.24%, further can be 0.18% - 0.24%, still further can be 0.19% - 0.24%.

[0106] In this application, the calculation method of the silicon hydride content is the ratio of the hydrogen connected to silicon in the polysiloxane containing silicon hydride groups to the mass of the polysiloxane containing silicon hydride groups, with the unit of %. For example, for H-[-Si(CH3)2-O-] p -SiH(CH3)2, when p is 4, the calculated silicon hydride content is 2 / (74*4 + 60) = 0.56%.

[0107] In some embodiments, in the two-component silicone rubber composition, the structural formula of the first polysiloxane containing silicon hydride groups is Wherein, R 10 is H or C 1-6 alkyl group, and R 11 ~R 14 are each independently C 1-6 alkyl group; p is an integer selected from 2 to 10 or the silicon hydride content is 0.16% - 0.24%.

[0108] In some embodiments, in the structure of the first polysiloxane containing silicon hydride groups, R 13 and R 14 are both methyl groups.

[0109] In some embodiments, in the structure of the first polysiloxane containing silicon hydride groups, R11 ~R 14 are all methyl groups.

[0110] In some embodiments, in the two-component organosilicon rubber composition, the structural formula of the second hydrosilyl-containing polysiloxane is wherein, R 15 ~R 23 are each independently C 1-6 alkyl groups.

[0111] In some embodiments, in the two-component organosilicon rubber composition, the second hydrosilyl-containing polysiloxane contains only one silicon hydride group.

[0112] In some embodiments, in the two-component organosilicon rubber composition, in the second hydrosilyl-containing polysiloxane, the long-chain siloxane unit with the structure [SiR 18 R 19 -O] does not participate in the addition reaction and the crosslinking reaction, and the number of its repeating units affects the softness of the MQ resin and the balance with the hard segment units.

[0113] In some embodiments, in the structure of the second hydrosilyl-containing polysiloxane, x is an integer selected from 10 to 20, further can be an integer selected from 12 - 20, still further can be an integer selected from 14 - 20, and can also be one of the following integers or an interval composed of two of them: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.

[0114] In some embodiments, in the structure of the second hydrosilyl-containing polysiloxane, R 18 and R 19 are all methyl groups.

[0115] In the second hydrosilyl-containing polysiloxane, the long-chain siloxane unit with the structure [SiHR 20 -O] participates in the addition reaction, and the number of its repeating units affects the number of vinyl groups available for addition.

[0116] In some embodiments, in the structure of the second hydrosilyl-containing polysiloxane, y is an integer selected from 8 to 24, further can be an integer selected from 10 - 24, still further can be an integer selected from 13 - 24, and can also be one of the following integers or an interval composed of two of them: 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24.

[0117] In some embodiments, in the structure of the second hydrosilyl-containing polysiloxane, R 20 is methyl.

[0118] In some embodiments, in the second silicon hydride group-containing polysiloxane structure, x is an integer selected from 10 to 20, and y is an integer selected from 8 to 24; further, x is an integer selected from 12 - 20, and y is an integer selected from 10 - 24; still further, x is an integer selected from 14 - 20, and y is an integer selected from 13 - 24.

[0119] In some embodiments, in the second silicon hydride group-containing polysiloxane structure, the silicon hydride content is 0.5% - 0.8%, further it can be 0.55% - 0.8%, and still further it can be 0.60% - 0.8%.

[0120] In some embodiments, in the two-component organosilicon rubber composition, the structural formula of the second silicon hydride group-containing polysiloxane is wherein, R 15 ~R 23 are each independently C 1-6 alkyl, x is an integer selected from 10 to 20; y is an integer selected from 8 to 24 or the silicon hydride content is 0.5% - 0.8%.

[0121] In some embodiments, in the second silicon hydride group-containing polysiloxane structure, R 18 、R 19 、R 20 are all methyl.

[0122] In some embodiments, in the second silicon hydride group-containing polysiloxane structure, R 15 ~R 23 are all methyl.

[0123] In some embodiments, in the MQ silicone resin, the ratio of the number of monofunctional siloxane linkages to the number of tetrafunctional siloxane linkages is 0.5 - 1.2;

[0124] In some embodiments, in the MQ silicone resin, the vinyl content is 3% - 6%, further it can be 34% - 6%, and still further it can be 3.5% - 5%.

[0125] The MQ silicone resin is composed of organic and inorganic components, and its structure is similar to that of the silicone rubber base component, so it has good compatibility with silicone rubber.

[0126] Controlling the ratio of M / Q within a suitable range is beneficial to improving the compatibility between the MQ silicone resin and the silicone rubber. For example, through experiments, it is found that if the ratio of M / Q in the MQ silicone resin is lower than the suitable range, the compatibility between the MQ resin and the silicone rubber may be poor, phase separation is likely to occur, and even the dispersion uniformity is poor, which contributes less to the hardness enhancement effect of the system.

[0127] In some embodiments, in the two-component organosilicon rubber composition, the structural formula of the MQ silicone resin is [R d R e R f SiO 0.5 a [SiO2] b , where at least one of R d , R e , and R f is vinyl, and a / b = 0.5 to 1.2 or the vinyl content is 3% to 6%.

[0128] In some embodiments, in the two-component organosilicon rubber composition, in the structural formula of the MQ silicone resin, R d is vinyl, and R e , R f are C1-C3 alkyl groups.

[0129] Through experiments, the applicant also found that controlling the viscosity of the vinyl polysiloxane within a suitable range is beneficial to obtaining an organosilicon rubber product with better comprehensive performance. If the viscosity of the vinyl polysiloxane is lower than the suitable range, it may cause a relatively high crosslinking density, resulting in a relatively high strength and hardness of the prepared organosilicon rubber; if the viscosity of the vinyl polysiloxane is higher than the suitable range, it may cause a relatively high elasticity and elongation of the prepared organosilicon rubber. Controlling the ratio of the low-viscosity vinyl polysiloxane to the high-viscosity vinyl polysiloxane within a suitable range helps to prepare an organosilicon rubber with a moderate system viscosity and good comprehensive performance.

[0130] In some embodiments, in the two-component organosilicon rubber composition, the viscosity of the first vinyl polysiloxane is 60,000 cps to 100,000 cps, further preferably 90,000 cps to 100,000 cps, and even more preferably 85,000 cps to 100,000 cps.

[0131] In some embodiments, in the two-component organosilicon rubber composition, the viscosity of the second vinyl polysiloxane is 2,000 cps - 5,000 cps, further preferably 2,000 cps - 4,000 cps, and even more preferably 2,000 cps - 3,000 cps.

[0132] In some embodiments, in the two-component organosilicon rubber composition, the catalyst is a platinum complex, and the platinum complex is selected from the group consisting of β-diketone complexes, (η-cyclopentadienyl)tris(α-aliphatic)platinum complexes, and C1-C 20 aliphatic group-substituted (η-5-cyclopentadienyl)tris(α-aliphatic)platinum complexes. ​

[0133] The molar ratios of vinyl and photocatalyst in Component A and Component B affect the efficiency of the photocatalytic reaction and the residue of the catalyst, thereby affecting the yellowing resistance and mechanical properties of the cured product. Controlling the weight of the catalyst relative to the molar ratio of vinyl in Component A and Component B within a suitable range is beneficial to improving the catalytic efficiency of the curing reaction and the properties of the cured product. Through experiments, it is found that if the weight of the catalyst relative to the molar ratio of vinyl in Component A and Component B is lower than the suitable range, the photocatalytic reaction rate may be slow, the curing efficiency is low, and the comprehensive properties of the prepared organosilica gel are poor; if the weight of the catalyst relative to the molar ratio of vinyl in Component A and Component B is higher than the suitable range, the photocatalytic reaction rate may be slow, the curing efficiency is low, and the comprehensive properties of the prepared organosilica gel are poor.

[0134] In some embodiments, in the two-component organosilica gel composition, the weight ratio of the first vinyl polysiloxane to the second vinyl polysiloxane is (900 - 2200):1, further can be (900 - 2150):1, and still further can be (915 - 2130):1.

[0135] In some embodiments, in the two-component organosilica gel composition, the weight ratio of the first silicon hydride group-containing polysiloxane to the second silicon hydride group-containing polysiloxane is (2 - 4):1, further can be (2.35 - 4):1, and still further can be (2.35 - 3.6):1.

[0136] In some embodiments, in the two-component organosilica gel composition, the ratio of the weight of the vinyl MQ silicone resin to the sum of the weights of the first vinyl polysiloxane and the second vinyl polysiloxane is (0.001 - 0.01):1, further can be (0.002 - 0.01):1, and still further can be (0.003 - 0.01):1.

[0137] In some embodiments, in the two-component organosilica gel composition, the ratio of the sum of the weights of the first silicon hydride group-containing polysiloxane and the second silicon hydride group-containing polysiloxane to the sum of the weights of the first vinyl polysiloxane and the second vinyl polysiloxane is (0.1 - 0.2):1, further can be (0.1 - 0.18):1, and still further can be (0.11 - 0.165):1.

[0138] In the second aspect of the present application, a method for preparing an organosilica gel is provided, using Component A and Component B to prepare mixed glue A and mixed glue B respectively.

[0139] In some embodiments, the method for preparing the organosilica gel comprises the following steps:

[0140] S100: Mix the first vinyl polysiloxane, the first vinyl polysiloxane, the first silicon hydride group-containing polysiloxane, and the second silicon hydride group-containing polysiloxane in the A component, and defoam to obtain a mixed gel A; Mix the first vinyl polysiloxane and vinyl MQ silicone resin, defoam, then add a photocatalyst and continue to mix and defoam to obtain a mixed gel B;

[0141] S200: Mix the mixed gel A and the mixed gel B in a suitable weight ratio, and cure by ultraviolet light to obtain the organosilica gel.

[0142] In some embodiments, the method for preparing the organosilica gel comprises the following steps:

[0143] S100: Mix the first vinyl polysiloxane, the first vinyl polysiloxane, the first silicon hydride group-containing polysiloxane, and the second silicon hydride group-containing polysiloxane in the A component, and defoam to obtain a mixed gel A; Mix the first vinyl polysiloxane and vinyl MQ silicone resin, defoam, then add a photocatalyst and continue to mix and defoam to obtain a mixed gel B; S200: Mix the mixed gel A and the mixed gel B in a weight ratio of (8-12):1, and cure by ultraviolet light to obtain the organosilica gel.

[0144] In some embodiments, the method for preparing the organosilica gel comprises the following steps:

[0145] S100: Mix the first vinyl polysiloxane, the first vinyl polysiloxane, the first silicon hydride group-containing polysiloxane, and the second silicon hydride group-containing polysiloxane in the A component at a suitable temperature, and defoam for a suitable time to obtain a mixed gel A; Mix the first vinyl polysiloxane and vinyl MQ silicone resin at a suitable temperature, defoam for a suitable time, then add a photocatalyst and continue to mix and defoam for a suitable time to obtain a mixed gel B;

[0146] S200: Mix the mixed gel A and the mixed gel B in a weight ratio of (8-12):1, and cure by ultraviolet light to obtain the organosilica gel.

[0147] In some embodiments, the method for preparing the organosilica gel comprises the following steps:

[0148] S100: Place the first vinyl polysiloxane, the first vinyl polysiloxane, the first silicon hydride group-containing polysiloxane, and the second silicon hydride group-containing polysiloxane in the A component in a vacuum degassing machine, mix them at a suitable temperature, and degas to obtain mixed glue A; Place the first vinyl polysiloxane and vinyl MQ silicone resin in a vacuum degassing machine, mix and degas them at a suitable temperature. After allowing the stirred solution to stand and dissipate heat, add a photocatalyst and continue to mix and degas to obtain mixed glue B;

[0149] S200: Mix and stir the mixed glue A and the mixed glue B in a vacuum degassing machine according to a weight ratio of (8 - 12):1, and cure them by ultraviolet light to obtain an organic silicone rubber.

[0150] There is no sequential order for the preparation of the mixed glue A and the mixed glue B.

[0151] Mix and degas a part of vinyl mono-capped polysiloxane, vinyl bis-capped polysiloxane, and silicon hydride-containing polysiloxane to obtain mixed glue A, and mix and degas another part of vinyl mono-capped polysiloxane, vinyl MQ silicone resin, and a catalyst to obtain mixed glue B; Then mix mixed glue A and mixed glue B according to a ratio and treat them with ultraviolet light, and an organic silicone rubber with a suitable crosslinking degree and fewer residual active groups can be obtained at a faster photocuring speed with a smaller amount of catalyst; This preparation process has a simple process, high photocatalytic efficiency, does not require high temperature, does not add auxiliary components such as inhibitors and additives, and is environmentally friendly.

[0152] In some embodiments, in the step of mixing the raw materials in the A component in the preparation method of the organic silicone rubber, the mixing time is 2 min to 4 min, further it can be 2 min to 3.5 min, and still further it can be 2 min to 3 min.

[0153] In some embodiments, in the step of mixing the raw materials in the A component in the preparation method of the organic silicone rubber, the mixing temperature is 25°C ± 1°C.

[0154] In some embodiments, in the step of mixing the raw materials in the A component in the preparation method of the organic silicone rubber, the mixing time is 2 min to 4 min and the mixing temperature is 25°C ± 1°C.

[0155] In some embodiments, in the step of mixing and degassing the raw materials in the A component in the preparation method of the organic silicone rubber, the degassing time is 1 min to 2 min, further it can be 1 min to 1.5 min.

[0156] In some embodiments, in the step of mixing and degassing the raw materials in the A component in the preparation method of the organic silicone rubber, the degassing temperature is 25°C ± 1°C.

[0157] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing and degassing the raw materials in component A, the degassing time is 1 min to 2 min, and the degassing temperature is 25°C ± 1°C.

[0158] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing the raw materials in component B, the mixing time is 2 min to 4 min, further preferably 2 min to 3.5 min, and even more preferably 2 min to 3 min.

[0159] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing the raw materials in component B, the mixing temperature is 25°C ± 1°C.

[0160] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing the raw materials in component B, the mixing time is 2 min to 4 min, and the mixing temperature is 25°C ± 1°C.

[0161] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing and degassing the raw materials in component B, the degassing time is 1 min to 2 min, further preferably 2 min to 1.5 min.

[0162] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing and degassing the raw materials in component B, the degassing temperature is 25°C ± 1°C.

[0163] In some embodiments, in the method for preparing the silicone rubber, in the step of mixing and degassing the raw materials in component B, the degassing time is 2 min to 4 min, and the degassing temperature is 25°C ± 1°C.

[0164] In some embodiments, in the method for preparing the silicone rubber, the wavelength of the ultraviolet light for ultraviolet curing is 320 nm to 420 nm, further preferably 340 nm to 420 nm, and even more preferably 360 nm to 420 nm.

[0165] In some embodiments, in the method for preparing the silicone rubber, the time for ultraviolet curing is 1 min to 3 min, further preferably 1 min to 2.5 min, and even more preferably 1 min to 2 min.

[0166] In some embodiments, in the method for preparing the silicone rubber, the temperature for ultraviolet curing is 25°C ± 1°C.

[0167] In some embodiments, in the preparation method of the organosilicone, the wavelength of the ultraviolet light for ultraviolet curing is 320 nm to 420 nm, the time is 1 min to 3 min, and the temperature is 25°C ± 1°C.

[0168] In some embodiments, in the preparation method of the organosilicone, the wavelength of the ultraviolet light for ultraviolet curing is 360 nm to 420 nm, the time is 1 min to 2 min, and the temperature is 25°C ± 1°C.

[0169] In some embodiments, the preparation method of the organosilicone includes the following steps:

[0170] S100: According to the formula, put the first vinyl polysiloxane (viscosity 60000 cps, vinyl content 0.05%-0.10%), the second vinyl polysiloxane (viscosity 2000 cps - 5000 cps, vinyl content 0.15 - 0.25%), the first silicon hydride group-containing polysiloxane (silicon hydride content 0.16% - 0.24%), and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.5% - 0.8%) in the A component into a vacuum degassing machine for mixing and degassing (25°C, 3 min to 5.5 min) to obtain the mixed glue A; put the first vinyl polysiloxane (viscosity 60000 cps, vinyl content 0.05%-0.10%) and vinyl MQ (vinyl content 3%-6%) silicone resin in the B component into a vacuum degassing machine for mixing, degassing (25°C), after the stirred solution is allowed to stand and dissipate heat, then add a photocatalyst and continue to carry out vacuum degassing (25°C, 3 min to 5.5 min) to obtain the mixed glue B;

[0171] S200: Mix and stir the mixed glue A and the mixed glue B in a vacuum degassing machine according to a weight ratio of (8 - 12):1, place them in a vacuum degassing machine, and cure them by ultraviolet light (25°C, 1 min to 1.5 min) to obtain the organosilicone.

[0172] The preparation method of the organosilicone described in the second aspect, the organosilicone composition is as defined in the first aspect.

[0173] In the third aspect of the present application, an organosilicone is provided, which is prepared according to the preparation method described in the second aspect.

[0174] The chemical structure of the organosilicone contains siloxane repeating units with a relatively large degree of polymerization and high viscosity, and in the crosslinked network double bondLess, free of phenyl, naphthyl or amino groups, etc., it has good aging resistance and yellowing resistance. In addition, vinyl MQ resin is introduced, which forms a dispersed phase in the silicone rubber and maintains a certain continuity, and also gives the silicone rubber better toughness. This silicone rubber has good aging resistance, yellowing resistance and mechanical properties, with simple and stable composition, and can be applied to the encapsulation of semiconductor devices.

[0175] In the fourth aspect of the present application, there is provided an application of the two-component silicone rubber composition described in the first aspect, the silicone rubber prepared by the silicone rubber described in the third aspect or the preparation method described in the second aspect in LED encapsulation, semiconductor manufacturing or transparent product assembly.

[0176] To make the present invention easier to understand and implement, the following provides some more easily implemented, more specific and detailed examples and comparative examples for reference.

[0177] Unless otherwise specified, the raw materials used in the following tests can be routinely purchased from the market.

[0178] In the following examples, unless otherwise specified, the performance test methods and evaluation criteria in the present application are as follows:

[0179] Aging resistance: The aging resistance of the silicone rubber is tested using a high and low temperature and humidity test chamber. The test method is to conduct the test in an environment of 85°C / 85RH. Specifically, take 2 small glass pieces of 4 cm x 5 cm, stick 0.5 mm gaskets around them, apply the silicone rubber on the glass, cover the two pieces of glass, bake in an oven at 70°C for 2H to cure, and then put it into an 85°C / 85RH aging test chamber. The aging value (yellowing degree) of the silicone rubber sample is tested by a color haze meter (CS-700) to judge the aging resistance of the material after a certain period of time of testing. After 1000h of testing, the measured aging value can be referred to Table 2. When the aging value ≤ 0.5, it is excellent; when 0.5 < aging value ≤ 0.6, it is qualified; when the aging value > 0.8, it is unqualified.

[0180] Yellowing resistance: The yellowing resistance of the silicone rubber is tested using an ultraviolet aging test chamber. The test method is to conduct the test in an environment of 60°C / 0.76W / cm 2The test was carried out under the following environment. Specifically, two small glass pieces of 4 cm x 5 cm were taken, and gaskets of 0.5 mm were pasted around them. The silicone rubber was coated on the glass, and the two pieces of glass were covered and then put into an oven at 70 °C for baking and curing for 2 hours, and then put into an 85 °C / 85 RH aging test chamber. The yellowing value (yellowness) of the silicone rubber sample was measured by a color haze meter (CS-700) to judge the yellowing resistance performance of the material after a certain specific time test: after 1000 hours of testing, the measured yellowing value can be referred to Table 3. When the yellowing value ≤ 0.3, it is excellent; when 0.3 ≤ yellowing value ≤ 0.4, it is qualified; when the yellowing value > 0.6, it is unqualified.

[0181] Penetration performance: Take the silicone rubber, cure it at 70 °C for 2 hours and then let it cool, put it on a penetrometer, and the size of the penetration is indicated by the depth of the needle on the penetrometer piercing into the colloid. The penetration performance is judged by the size of the measured penetration resin of the resin, which can be referred to Table 4. After testing, when 90 < penetration ≤ 100, it is excellent; when 100 < penetration ≤ 105, it is qualified; when the penetration > 110 or the penetration ≤ 90, it is unqualified.

[0182] The following are specific examples

[0183] Table 1 A component and B component in the two-component silicone rubber compositions of Examples 1-5 and Comparative Examples 1-3

[0184]

[0185] Example 1

[0186] According to the formula in Table 1, the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) in component A, the second vinyl polysiloxane (viscosity 2000 cps, vinyl content 0.25%), the first silicon hydride group-containing polysiloxane (silicon hydride content 0.20%), and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.75%) were placed in a vacuum degassing machine for mixing and degassing (25 °C, 3 min) to obtain a mixed rubber A; the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) and vinyl MQ (vinyl content 3.5%) silicone resin in component B were placed in a vacuum degassing machine for mixing and degassing (25 °C), and the stirred solution was allowed to stand and dissipate heat and then 0.05 of photocatalyst was added and continued to be vacuum degassed (25 °C, 3 min) to obtain a mixed rubber B;

[0187] The mixed rubber A and the mixed rubber B were mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25 °C, 1 min) to obtain a silicone rubber.

[0188] Using the aforementioned test method, the aging resistance, yellowing resistance and penetration properties of this silicone rubber were measured as shown in Tables 2 to 4 respectively.

[0189] Example 2

[0190] According to the formulation in Table 1, the first vinyl polysiloxane (viscosity 90000 cps, vinyl content 0.07%) and the second vinyl polysiloxane (viscosity 2000 cps, vinyl content 0.25%) in component A, the first silicon hydride group-containing polysiloxane (silicon hydride content 0.2%) and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.68%) were placed in a vacuum degassing machine for mixing and degassing (25°C, 3 min) to obtain mixed rubber A; the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) and vinyl MQ (vinyl content 3.5%) silicone resin in component B were placed in a vacuum degassing machine for mixing and degassing (25°C), and the stirred solution was allowed to stand and dissipate heat, then 0.04 of photocatalyst was added and vacuum degassing was continued (25°C, 3 min) to obtain mixed rubber B;

[0191] Mixed rubber A and mixed rubber B were mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25°C, 3 min) to obtain silicone rubber.

[0192] Using the aforementioned test method, the aging resistance, yellowing resistance and penetration properties of this silicone rubber were measured as shown in Tables 2 to 4 respectively.

[0193] Example 3

[0194] According to the formulation in Table 1, the first vinyl polysiloxane (viscosity 85000 cps, vinyl content 0.075%), the second vinyl polysiloxane (viscosity 3000 cps, vinyl content 0.22%) in component A, the first silicon hydride group-containing polysiloxane (silicon hydride content 0.2%) and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.65%) were placed in a vacuum degassing machine for mixing and degassing (25°C, 2 min) to obtain mixed rubber A; the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) and vinyl MQ (vinyl content 5%) silicone resin in component B were placed in a vacuum degassing machine for mixing and degassing (25°C), and the stirred solution was allowed to stand and dissipate heat, then 0.05 of photocatalyst was added and vacuum degassing was continued (25°C, 3 min) to obtain mixed rubber B;

[0195] Mixed rubber A and mixed rubber B were mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25°C, 1.5 min) to obtain silicone rubber.

[0196] Using the aforementioned test method, the aging resistance, yellowing resistance and penetration properties of the silicone rubber were measured as shown in Tables 2 to 4 respectively.

[0197] Example 4

[0198] According to the formula in Table 1, the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) and the second vinyl polysiloxane (viscosity 2500 cps, vinyl content 0.24%) in component A, the first silicon hydride group-containing polysiloxane (silicon hydride content 0.22%) and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.65%) were placed in a vacuum degassing machine for mixing and degassing (25 °C, 3 min) to obtain mixed rubber A; the first vinyl polysiloxane (viscosity 90000 cps, vinyl content 0.07%) and vinyl MQ (vinyl content 5%) silicone resin in component B were placed in a vacuum degassing machine for mixing and degassing (25 °C), and the stirred solution was allowed to stand and dissipate heat, then 0.05 of photocatalyst was added and vacuum degassing was continued (25 °C, 3 min) to obtain mixed rubber B;

[0199] The mixed rubber A and the mixed rubber B were mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25 °C, 1 min) to obtain silicone rubber.

[0200] Using the aforementioned test method, the aging resistance, yellowing resistance and penetration properties of the silicone rubber were measured as shown in Tables 2 to 4 respectively.

[0201] Example 5

[0202] According to the formula in Table 1, the first vinyl polysiloxane (viscosity 90000 cps, vinyl content 0.07%) and the second vinyl polysiloxane (viscosity 2000 cps, vinyl content 0.25%) in component A, the first silicon hydride group-containing polysiloxane (silicon hydride content 0.2%) and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.7%) were placed in a vacuum degassing machine for mixing and degassing (25 °C, 2 min) to obtain mixed rubber A; the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) and vinyl MQ (vinyl content 4%) silicone resin in component B were placed in a vacuum degassing machine for mixing and degassing (25 °C), and the stirred solution was allowed to stand and dissipate heat, then 0.06 of photocatalyst was added and vacuum degassing was continued (25 °C, 3 min) to obtain mixed rubber B;

[0203] The mixed rubber A and the mixed rubber B were mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25 °C, 1 min) to obtain silicone rubber.

[0204] Using the aforementioned test methods, the aging resistance, yellowing resistance, and penetration properties of the silicone rubber were measured as shown in Tables 2 to 4 respectively.

[0205] Comparative Example 1

[0206] According to the formulation in Table 1, the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) in component A, the second vinyl polysiloxane (viscosity 2000 cps, vinyl content 0.25%), the first polysiloxane containing silicon hydride groups (silicon hydride content 0.24%), and the second polysiloxane containing silicon hydride groups (silicon hydride content 0.75%) were placed in a vacuum degassing machine for mixing and degassing (25°C, 2 min) to obtain mixed rubber A; the first vinyl polysiloxane (viscosity 100000 cps, vinyl content 0.05%) and vinyl MQ (vinyl content 3%) silicone resin in component B were placed in a vacuum degassing machine for mixing and degassing (25°C), and the stirred solution was allowed to stand and dissipate heat, then 0.03 of a photocatalyst was added and vacuum degassing was continued (25°C, 3 min) to obtain mixed rubber B;

[0207] Mixed rubber A and mixed rubber B were mixed and stirred in a vacuum degassing machine at a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25°C, 1 min) to obtain the silicone rubber.

[0208] Using the aforementioned test methods, the aging resistance, yellowing resistance, and penetration properties of the silicone rubber were measured as shown in Tables 2 to 4 respectively.

[0209] Compared with Examples 1 to 4, the aging value of the aging resistance performance parameter of the silicone rubber in Comparative Example 1 was significantly higher than that of Examples 1 to 5 at the same time; the yellowing value of the yellowing resistance performance parameter was also significantly higher than that of Examples 1 to 5 under the same test time; the penetration degree was also significantly lower than that of Examples 1 to 5. The reason may be that the weight fraction of the second polysiloxane containing silicon hydride groups used in the preparation process of Comparative Example 1 was 2.5, which was significantly larger than 0.7 to 1 part of Examples 1 to 5. The large silicon hydride amount in the polysiloxane containing silicon hydride groups caused the ratio to exceed the appropriate range. At the same time, the photocatalyst content was low, resulting in a large proportion of unreacted monomers in the finally prepared silicone rubber product, poor yellowing resistance performance, and poor comprehensive mechanical properties, large hardness, and small penetration degree of the silicone rubber.

[0210] Comparative Example 2

[0211] According to the formula in Table 1, the first vinyl polysiloxane (viscosity 90000 cps, vinyl content 0.07%) in Component A, the second vinyl polysiloxane (viscosity 2500 cps, vinyl content 0.24%), the first silicon hydride group-containing polysiloxane (silicon hydride content 0.2%), and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.7%) are placed in a vacuum degassing machine for mixing and degassing (25°C, 2 min) to obtain mixed glue A; the first vinyl polysiloxane (viscosity 90000 cps, vinyl content 0.07%) and vinyl MQ (vinyl content 5%) silicone resin in Component B are placed in a vacuum degassing machine for mixing and degassing (25°C), and the obtained solution is allowed to stand and dissipate heat, and then 0.1 of photocatalyst is added and vacuum degassing is continued (25°C, 3 min) to obtain mixed glue B;

[0212] The mixed glue A and the mixed glue B are mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25°C, 1 min) to obtain an organosilica gel.

[0213] Using the aforementioned test methods, the aging resistance, yellowing resistance, and penetration properties of the organosilica gel are shown in Tables 2 to 4 respectively.

[0214] Compared with Examples 1 to 4, the aging resistance value of the organosilica gel in Comparative Example 2 is significantly higher than that in Examples 1 to 5 at the same time; the QUV value of the yellowing resistance property is also significantly higher than that in Examples 1 to 5 under the same test time; the penetration is slightly lower than that in Examples 1 to 5. The possible reason is that the photocatalyst in Comparative Example 2 is 0.1, which is significantly larger than 0.04 to 0.06 parts in Examples 1 to 5, and the content of the first vinyl polysiloxane in Component A is relatively low, which may lead to a smaller degree of preliminary reaction during the mixing and degassing of Component A, is not conducive to the efficient progress of the photocatalysis process, and also affects the internal structure of the organosilica gel; at the same time, the content of the photocatalyst in the raw materials of Comparative Example 2 is relatively low, which may cause incomplete photocatalytic reaction and ultimately lead to poor aging resistance of the organosilica gel.

[0215] Comparative Example 3

[0216] According to the formulation in Table 1, the first vinyl polysiloxane (viscosity 100,000 cps, vinyl content 0.05%) in Component A, the second vinyl polysiloxane (viscosity 2,000 cps, vinyl content 0.25%), the first silicon hydride group-containing polysiloxane (silicon hydride content 0.2%), and the second silicon hydride group-containing polysiloxane (silicon hydride content 0.6%) were placed in a vacuum degassing machine for mixing and degassing (25 °C, 2 min) to obtain mixed rubber A; the first vinyl polysiloxane (viscosity 90,000 cps, vinyl content 0.07%) and vinyl MQ (vinyl content 6%) silicone resin in Component B were placed in a vacuum degassing machine for mixing and degassing (25 °C), and the stirred solution was allowed to stand and dissipate heat, then 0.07 of photocatalyst was added and vacuum degassing was continued (25 °C, 2 min) to obtain mixed rubber B;

[0217] The mixed rubber A and the mixed rubber B were mixed and stirred in a vacuum degassing machine according to a weight ratio of 10:1, placed in a vacuum degassing machine, and cured by ultraviolet light (ultraviolet light wavelength 360 nm, 25 °C, 1 min) to obtain an organosilica gel.

[0218] Using the aforementioned test methods, the aging resistance, yellowing resistance, and penetration properties of the organosilica gel were measured as shown in Tables 2 to 4 respectively.

[0219] Compared with Examples 1 to 4, the aging resistance and yellowing resistance performance values of the organosilica gel in Comparative Example 3 were the same as those in Examples 1 to 5 at the same time, while the penetration degree was significantly higher than that in Examples 1 to 5. The possible reason is that the dosage of the second silicon hydride group-containing polysiloxane in Comparative Example 3 was significantly less than that in Examples 1 to 5, and the proportion of the formed cross-linked structure was smaller. The first silicon hydride group-containing polysiloxane mainly forms long branched chains, and the vinyl MQ silicone resin mainly plays a role in dispersing and reinforcing the organosilica gel, and the latter two contribute less to cross-linking. Therefore, when a significantly small amount of the second silicon hydride group-containing polysiloxane was used in Comparative Example 3, fewer cross-linked structures were formed during the photocuring process and the hardness of the organosilica gel was smaller.

[0220] In addition, through experiments, the inventors also found that when only one kind of vinyl polysiloxane was selected, that is, only vinyl double-ended polysiloxane or vinyl single-ended polysiloxane was selected, the prepared organosilica gel was more brittle or had poor penetration degree, and introducing more MQ resin was likely to cause the prepared organosilica gel to become oily after standing, affecting the bonding performance.

[0221] When only one kind of silicon hydride group-containing polysiloxane was selected, that is, only polysiloxane with a high silicon hydride content or polysiloxane with a low silicon hydride content was selected, it was more difficult to control the comprehensive performance of the hardness and toughness of the prepared organosilica gel, and adding more photocatalyst could improve the mechanical properties but was likely to cause the deterioration of the yellowing resistance performance.

[0222] When the weight ratio of component A to component B is too small or too large, the comprehensive mechanical properties (such as penetration) and yellowing resistance and aging resistance of the prepared silicone rubber are poor.

[0223] When the initiator is pre-loaded into component A, the time required for defoaming becomes longer during the mixing of the components in component A and defoaming, the yellowing resistance of the prepared silicone rubber deteriorates, and the penetration decreases to a certain extent.

[0224] Table 2 Test results of the aging resistance of the silicone rubbers of Examples 1-5 and Comparative Examples 1-3

[0225]

[0226] In Table 2, H in 0H, 250H, 500H, and 1000H represents "hour".

[0227] Table 3 Test results of the yellowing resistance of the silicone rubbers of Examples 1-5 and Comparative Examples 1-3

[0228]

[0229] In Table 3, H in 0H, 250H, 500H, and 1000H represents "hour".

[0230] Table 4 Test results of the penetration performance of the silicone rubbers of Examples 1-5 and Comparative Examples 1-3

[0231]

[0232] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0233] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims, and the description can be used to explain the content of the claims.

Claims

1. A two-component organosilicon rubber composition, characterized in that, It includes component A and component B, where: By weight parts, the component A contains the following components: 30 - 60 parts of the first vinyl polysiloxane, 1 - 5 parts of the second vinyl polysiloxane, 1 - 3 parts of the first hydrosilyl group-containing polysiloxane, and 0.5 - 1.5 parts of the second hydrosilyl group-containing polysiloxane; By weight parts, the component B contains the following components: 20 - 40 parts of the first vinyl polysiloxane, 2 - 4 parts of vinyl MQ silicone resin, and 0.03 - 0.08 parts of photocatalyst; The first vinyl polysiloxane is a vinyl-terminated polysiloxane; The second vinyl polysiloxane is a vinyl-monoterminated polysiloxane; The MQ silicone resin is a silicone resin composed of monofunctional siloxane linkages and tetrafunctional siloxane linkages, and the MQ silicone resin contains vinyl; The weight ratio of the component A to the component B is (8 - 12):1; The structural formula of the first silicon hydride group-containing polysiloxane is wherein, R 10 is H or C 1-6 alkyl group, and R 11 ~R 14 are each independently C 1-6 alkyl group; p is an integer selected from 2 to 10 or the silicon hydride content is 0.16% to 0.24%; The structural formula of the second silicon hydride group-containing polysiloxane is wherein, R 15 ~R 23 are each independently C 1-6 alkyl group, x is an integer selected from 10 to 20; y is an integer selected from 8 to 24 or the silicon hydride content is 0.5% to 0.8%.

2. The two-component organosilicon rubber composition according to claim 1, characterized in that, It satisfies one or more of the following characteristics: The structural formula of the first vinyl polysiloxane is wherein, R1 to R4 are each independently C 1-6 alkyl group; m is an integer selected from 360 to 700 or the vinyl content is 0.05%-0.10%; The structural formula of the second vinyl polysiloxane is wherein, R5 to R9 are each independently C 1-6 alkyl group; n is an integer selected from 140 to 240 or the vinyl content is 0.15% - 0.25%; In the MQ silicone resin, the number ratio of monofunctional siloxane linkages to tetrafunctional siloxane linkages is 0.5 - 1.2; The vinyl content in the MQ silicone resin is 3% - 6%.

3. The two-component organosilicon rubber composition according to claim 1 or 2, characterized in that, The structural formula of the MQ silicone resin is [R d R e R f SiO 0.5 a [SiO2] b , where at least one of R d , R e , and R f is vinyl; a / b = 0.5 to 1.2 or the vinyl content is 3% to 6%.​ 4. The two-component organosilicon rubber composition according to claim 1 or 2, characterized in that, It satisfies one or two of the following characteristics: The viscosity of the first vinyl polysiloxane is 60000 cps - 100000 cps; The viscosity of the second vinyl polysiloxane is 2000 cps - 5000 cps.

5. The two-component organosilicon rubber composition according to claim 1 or 2, characterized in that, The photocatalyst is a platinum complex, and the platinum complex is selected from β-diketone complexes, (η-cyclopentadienyl)tris(α-aliphatic)platinum complexes, and C1-C 20 an (η-5-cyclopentadienyl)tris(α-aliphatic)platinum complex substituted with an aliphatic group.

6. The two-component organosilicon rubber composition according to claim 1 or 2, characterized in that, It satisfies one or more of the following characteristics: The weight ratio of the first vinyl polysiloxane to the second vinyl polysiloxane is (6.5 - 65):1; The weight ratio of the first hydrosilyl group-containing polysiloxane to the second hydrosilyl group-containing polysiloxane is (2 - 4):1; The weight ratio of the vinyl MQ silicone resin to the sum of the weights of the first vinyl polysiloxane and the second vinyl polysiloxane is (0.001 - 0.01):1; The weight ratio of the sum of the weights of the first hydrosilyl group-containing polysiloxane and the second hydrosilyl group-containing polysiloxane to the sum of the weights of the first vinyl polysiloxane and the second vinyl polysiloxane is (0.1 - 0.2):

1.

7. A method for preparing an organosilicon rubber, characterized in that, It includes the following steps: According to the two-component organosilicon rubber composition described in any one of claims 1 - 5, provide component A and component B; Use the component A and the component B to prepare mixed rubber A and mixed rubber B respectively; among them, mix the first vinyl polysiloxane, the first vinyl polysiloxane, the first hydrosilyl group-containing polysiloxane, and the second hydrosilyl group-containing polysiloxane in the component A, and defoam to obtain mixed rubber A; mix the first vinyl polysiloxane and vinyl MQ silicone resin in the component B, defoam, and then add the photocatalyst and continue to mix and defoam to obtain mixed rubber B; Mix the mixed rubber A and the mixed rubber B according to a weight ratio of (8 - 12):1, and cure by ultraviolet light to obtain organosilicon rubber.

8. The preparation method according to claim 7, characterized in that, It satisfies one or more of the following: In the step of mixing the raw materials in the component A, the mixing time is 2 min - 4 min; In the step of mixing the raw materials in the A component, the mixing temperature is 25°C ± 1°C; In the step of mixing and degassing the raw materials in the A component, the degassing time is 1 min to 2 min; In the step of mixing and degassing the raw materials in the A component, the degassing temperature is 25°C ± 1°C; In the step of mixing the raw materials in the B component, the mixing time is 2 min to 4 min; In the step of mixing the raw materials in the B component, the mixing temperature is 25°C ± 1°C; In the step of mixing and degassing the raw materials in the B component, the degassing time is 1 min to 2 min; In the step of mixing and degassing the raw materials in the B component, the degassing temperature is 25°C ± 1°C; The wavelength of the ultraviolet light for the ultraviolet curing is 320 nm to 420 nm; The time for the ultraviolet curing is 1 min to 3 min; The temperature for the ultraviolet curing is 25°C ± 1°C.

9. An organosilicon rubber, characterized in that, Prepared by the preparation method according to claim 7 or 8.

10. Use of the two-component organosilicon rubber composition according to any one of claims 1 to 5, the organosilicon rubber according to claim 9 or the organosilicon rubber prepared by the preparation method according to claim 7 or 8 in LED packaging, semiconductor manufacturing or transparent product assembly.

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