Adamantane modified silane coupling agent, single-component dealcoholized silicone rubber and preparation method of single-component dealcoholized silicone rubber

Abstract

The invention discloses an adamantane modified silane coupling agent, single-component dealcoholized silicone rubber and a preparation method of the single-component dealcoholized silicone rubber. The adamantane modified silane coupling agent is obtained by sequentially reacting adamantanol with tetramethyl divinyl disilazane and a modifier, the structural formula of the modifier is shown in the specification. The cross-linking agent in the single-component dealcoholized silicone rubber disclosed by the invention is the adamantane modified silane coupling agent disclosed by the invention. The single-component dealcoholized silicone rubber prepared by taking the adamantane modified silane coupling agent as the cross-linking agent has relatively high tensile strength and elongation at break, and has good comprehensive mechanical properties. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber, in particular to dealcoholized silicone rubber, and in particular to an adamantane-modified silane coupling agent, a single-component dealcoholized silicone rubber and a preparation method thereof. Background Art

[0002] Silane coupling agent, as an important classification of coupling agents, is an organosilicon compound with two or more different reactive groups. It can act as a reactive "bridge" to chemically bond organic materials and inorganic materials. At present, one of the important uses of silane coupling agent is as a cross-linking agent, which acts as a "bridge" to build a three-dimensional network structure of siloxane to obtain room temperature vulcanized silicone rubber. New cross-linking agents give room temperature vulcanized silicone rubber better performance or special functionality by introducing different functional groups and molecular structure design. There are more than a hundred kinds of silane coupling agents with known structures, and the prepared silicone rubber has been widely used in major fields such as construction, medical treatment, electronics and electrical, photovoltaics, batteries, energy storage, aerospace, etc.

[0003] With the development of science and technology, higher expectations have been put forward for the advanced indicators of functional materials. Common crosslinkers for dealcoholized RTV-1 silicone rubber, such as vinyl trimethoxysilane, methyl trimethoxysilane, tetramethoxysilane, etc., have limited improvement on the mechanical properties of silicone rubber and are obviously not suitable for new requirements. In recent years, the newly launched phenyltrimethoxysilane coupling agent improves the elongation of silicone rubber while improving its heat resistance, but it will reduce the tensile strength of silicone rubber; the launch of the disilane coupling agent 1,2-bis(trimethoxysilyl)ethane, that is, there are two silane structures in the same molecular structure, one of its molecules has 6 alkoxy groups, which can form a higher cross-linking density on the surface of inorganic materials. The silanol formed after hydrolysis is more acidic than the silanol formed by ordinary silane coupling agents, so it can form a stronger covalent bond with the hydroxyl groups on the surface of metals and inorganic materials, and is not easy to hydrolyze, thereby improving water resistance; in addition, there are alkoxysilane oligomers, which have the characteristics of low odor, low volatility, high flash point, etc. By increasing the cross-linking points on the coupling agent, the curing speed and mechanical strength can be increased; but these silane coupling agents that increase the cross-linking density of the silicone rubber network by increasing the cross-linking points will lead to a decrease in the elongation of silicone rubber.

[0004] Therefore, there is an urgent need to further study and develop a new coupling agent to simultaneously improve the mechanical properties of silicone rubber, such as tensile strength and elongation. Summary of the invention

[0005] Based on this, the object of the present invention is to provide a crosslinking agent that can simultaneously improve the tensile strength and elongation of silicone rubber, and to provide a single-component dealcoholized silicone rubber having both high tensile strength and elongation.

[0006] In order to achieve the above object, the present invention includes the following technical solutions.

[0007] In a first aspect, the present invention provides an adamantane-modified silane coupling agent having the following structure:

[0008]

[0009] wherein each X is independently selected from: -H, -OH and -R;

[0010] Each R is independently selected from:

[0011] n is 0 or an integer greater than 0;

[0012] Y 1 OCH 3 or -OCH 2 CH 3 , Y 2 OCH 3 、-OCH 2 CH 3 、-CH 3 .

[0013] The adamantane-modified silane coupling agent of the present invention is obtained by sequentially reacting adamantane alcohol with tetramethyldivinyldisilazane and a modifier;

[0014] The structural formula of the modifier is:

[0015] Wherein, n is 0 or an integer greater than 0;

[0016] Y 1 OCH 3 or -OCH 2 CH 3 , Y 2 OCH 3 、-OCH 2 CH 3 、-CH 3 .

[0017] In a second aspect, the present invention provides a method for preparing the adamantane-modified silane coupling agent, comprising the following steps:

[0018] (1) reacting the adamantane alcohol with tetramethyldivinyldisilazane to obtain an intermediate product;

[0019] (2) The intermediate product reacts with the modifier under the action of a platinum catalyst to obtain the adamantane-modified silane coupling agent.

[0020] In a third aspect, the present invention provides the use of the adamantane-modified silane coupling agent as a cross-linking agent in the preparation of a single-component dealcoholized silicone rubber.

[0021] In a fourth aspect, the present invention provides a one-component dealcoholized silicone rubber, wherein the crosslinking agent is the adamantane-modified silane coupling agent described in the present invention.

[0022] For example, the one-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight:

[0023]

[0024] In a fifth aspect, the present invention provides a method for preparing the one-component dealcoholized silicone rubber of the present invention, comprising the steps of: mixing the base polymer, filler, and plasticizer evenly and then heating and dehydrating the mixture; adding the cross-linking agent, coupling agent, and catalyst after cooling and mixing evenly to obtain the one-component dealcoholized silicone rubber.

[0025] The present invention has the following beneficial effects:

[0026] The present invention designs and synthesizes a type of silane coupling agent with adamantyl as the core, and uses it as a crosslinking agent to prepare a single-component dealcoholized silicone rubber that is vulcanized at room temperature. The three-dimensional adamantane cage structure is introduced into the siloxane network, which can increase the rigid fulcrum and hydrogen bond binding point of the siloxane network. At the same time, the adamantane cage structure is hollow and has a large specific surface area, which can jointly improve the mechanical strength of the silicone rubber; at the same time, the adamantyl group has a large steric hindrance, and the effect of weakening the intermolecular force is more obvious. The activity space between the polymer molecular chains is large, which can reduce the cohesive force of the silicone rubber and improve the elongation of the silicone rubber.

[0027] The single-component dealcoholized silicone rubber prepared by using adamantane-modified silane coupling agent as a crosslinking agent has high tensile strength and elongation at break and good comprehensive mechanical properties. The tensile strength and elongation of the obtained silicone rubber can be further greatly improved through the coordinated coordination of reasonable chain length and structure, and the silicone rubber has a reasonable surface drying time, thereby improving its construction performance and having excellent comprehensive performance.

[0028] The preparation method of the adamantane-modified silane coupling agent of the present invention is simple and has good reproducibility, and can be applied to the design and preparation of silicone rubber without special processes, thereby improving the comprehensive mechanical properties of silicone rubber and facilitating industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 IR graphs of the intermediate product (a) obtained in step (1) of Example 1 and the adamantane-modified silane coupling agent (b) obtained in step (2). DETAILED DESCRIPTION

[0030] The technical scheme of the present invention is further illustrated by specific examples below. Those skilled in the art should understand that the examples are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used 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.

[0032] The terms "including" and "having" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products or equipment.

[0033] In the present invention, the term "multiple" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0034] Some embodiments of the present invention relate to an adamantane-modified silane coupling agent having the following structure:

[0035]

[0036] wherein each X is independently selected from: -H, -OH and -R;

[0037] Each R is independently selected from:

[0038] n is 0 or an integer greater than 0;

[0039] Y 1 OCH 3 or -OCH 2 CH 3 , Y 2 OCH 3 、-OCH 2 CH 3 、-CH 3 .

[0040] In some preferred embodiments, X is hydrogen.

[0041] In some preferred embodiments, 1 X is hydrogen and 2 X are R.

[0042] In some preferred embodiments, 2 X are hydrogen and 1 X is R.

[0043] In some preferred embodiments, all three X are R.

[0044] In some preferred embodiments, n is an integer between 0 and 50, preferably an integer between 5 and 30, and more preferably an integer between 8 and 15. For example, n can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, etc.

[0045] In some preferred embodiments, Y 1 OCH 3 , Y 2 OCH 3 .

[0046] In some preferred embodiments, Y 1 OCH 3 , Y 2 -CH 3 .

[0047] The adamantane-modified silane coupling agent of the present invention is obtained by sequentially reacting adamantane alcohol with tetramethyldivinyldisilazane and a modifier;

[0048] The structural formula of the modifier is:

[0049] Wherein, n is 0 or an integer greater than 0;

[0050] Y 1 OCH 3 or -OCH 2 CH 3 , Y 2 OCH 3 、-OCH 2 CH 3 、-CH 3 .

[0051] In some preferred embodiments, the molar ratio of the hydroxyl group in the adamantane alcohol to the tetramethyldivinyldisilazane and the modifier is 1:(0.5-20):(0.8-2), preferably 1:(1-5):(1-1.5).

[0052] In some preferred embodiments, the adamantane alcohol is selected from one or more combinations of 1-adamantanol, adamantane-1,3-diol, adamantane-1,3,5-triol, adamantane-1,3,5,7-tetraol and 1-adamantanethanol.

[0053] In some preferred embodiments, n is an integer between 0 and 50, preferably an integer between 5 and 30, and more preferably an integer between 8 and 15. For example, n can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, etc.

[0054] In some preferred embodiments, Y 1 OCH 3 , Y 2 OCH 3 .

[0055] In some preferred embodiments, Y 1 OCH 3 , Y 2 -CH 3 .

[0056] Some embodiments of the present invention also involve a method for preparing the adamantane-modified silane coupling agent, comprising the following steps:

[0057] (1) reacting the adamantane alcohol with tetramethyldivinyldisilazane to obtain an intermediate product;

[0058] (2) The intermediate product reacts with the modifier under the action of a platinum catalyst to obtain the adamantane-modified silane coupling agent.

[0059] In some preferred embodiments, the platinum catalyst is selected from at least one of a platinum-vinyl complex and a platinum-alkyne complex, preferably bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum(0) and / or trimethyl(methylcyclopentadienyl)platinum(IV).

[0060] In some embodiments, the reactions in step (1) and step (2) are both carried out in an organic solvent, and the organic solvent is preferably ethyl acetate.

[0061] In some preferred embodiments, the reaction temperature in step (1) is 40° C. to 90° C., and the reaction time is 0.5 h to 8 h.

[0062] In some preferred embodiments, the reaction temperature in step (1) is 70° C. to 90° C., and the reaction time is 1 h to 3 h.

[0063] In some preferred embodiments, the reaction temperature in step (2) is 10°C to 100°C, and the reaction time is 0.5h to 5h.

[0064] In some preferred embodiments, the reaction temperature in step (2) is 60° C. to 80° C., and the reaction time is 1 h to 3 h.

[0065] Some embodiments of the present invention also involve the use of the adamantane-modified silane coupling agent as a cross-linking agent in the preparation of a single-component dealcoholized silicone rubber.

[0066] Some embodiments of the present invention also involve a one-component dealcoholized silicone rubber, whose crosslinking agent is the adamantane-modified silane coupling agent described in the present invention.

[0067] In some embodiments, the one-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight:

[0068]

[0069] In some preferred embodiments, the single-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight:

[0070]

[0071] In some preferred embodiments, the single-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight:

[0072]

[0073]

[0074] In some preferred embodiments, the base polymer is terminal hydroxyl polydimethylsiloxane or terminal alkoxy polydimethylsiloxane, and the viscosity of the base polymer at 23°C is preferably 1500mP·s to 80000mP·s, more preferably 10000mP·s to 80000mP·s, more preferably 10000mP·s to 50000mP·s, more preferably 18000mP·s to 22000mP·s.

[0075] In some preferred embodiments, the filler is selected from one or more combinations of fumed silica, nano-calcium carbonate, titanium dioxide, kaolin, diatomaceous earth, silica powder, mica and barium sulfate.

[0076] In some embodiments, the filler is a combination of nano calcium carbonate and R812 fumed silica, and the mass ratio of nano calcium carbonate to R812 fumed silica is preferably 5-8:1, more preferably 6-7:1.

[0077] In some preferred embodiments, the plasticizer is selected from at least one of dimethyl silicone oil, methoxy silicone oil, MDT silicone oil and hydroxy silicone oil, and the viscosity of the plasticizer at 23° C. is preferably 50 mP·s to 1000 mP·s, more preferably 300 mP·s to 500 mP·s.

[0078] In some preferred embodiments, the coupling agent is selected from one or more combinations of 3-aminopropyltrimethoxysilane, N-cyclohexyl-γ-aminopropylmethyldimethoxysilane, bis(3-trimethoxysilylpropyl)amine, aminosilane oligomers, cyanopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane and 3-ureidopropyltriethoxysilane.

[0079] In some preferred embodiments, the catalyst is one or more combinations of organotin catalysts and phthalate catalysts.

[0080] In some preferred embodiments, the organotin catalyst is selected from at least one of dibutyltin dilaurate, dibutyltin diacetate, dimethyltin dineolenate and dibutyltin bisacetylacetonate.

[0081] In some preferred embodiments, the phthalate catalyst is selected from at least one of tetra-n-butyl titanate, polytetra-n-butyl titanate, 2-ethylhexyloxy titanate, 1,3-propylenedioxytitanium bis(ethyl acetoacetate) (acetylacetone) and diisopropyl bis(ethyl acetoacetate).

[0082] Some embodiments of the present invention also involve a method for preparing a one-component dealcoholized silicone rubber, comprising the following steps: uniformly mixing the base polymer, filler, and plasticizer, heating and dehydrating the mixture, cooling the mixture, adding the crosslinking agent, coupling agent, and catalyst, and uniformly mixing the mixture to obtain the one-component dealcoholized silicone rubber.

[0083] The following are specific embodiments.

[0084] The "parts" described in the following examples refer to parts by weight unless otherwise specified.

[0085] The general formula of the modifier in the following examples is as follows:

[0086]

[0087] Example 1

[0088] 1. Preparation of adamantane-modified silane coupling agent

[0089]

[0090] (1) Dissolve 0.1 mol of adamantane-1-ol in 30 ml of ethyl acetate, add 0.15 mol of tetramethyldivinyldisilazane while stirring, and heat to 80°C with sufficient stirring to reflux for 2 hours. Then, remove the solvent and unreacted silazane by distillation under reduced pressure; wash the obtained solid product with deionized water until the filtrate is neutral, and then dry it for later use.

[0091] (2) The product obtained in step (1) was redissolved in 50 ml of ethyl acetate. After it was fully dissolved, 0.11 mol of a modifier (n=10, Y 1 OCH 3 , Y 2 OCH 3 ) and dispersed evenly, added 0.0001 mol of bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum(0) under stirring, heated to 70°C and stirred for reaction for 2h, and the solvent was removed under reduced pressure to obtain a colorless or light yellow liquid, i.e., adamantane-modified silane coupling agent.

[0092] The IR spectrum of the intermediate product obtained in step (1) is as follows: Figure 1 As shown in a, at 1630cm -1 The IR diagram of the adamantane-modified silane coupling agent obtained in step (2) is as follows: Figure 1 As shown in b: 1630cm -1 The deformation vibration peak of the carbon-carbon double bond C=C disappears at 1270m -1 The CO stretching vibration on the methoxy group.

[0093] 2. Preparation of single-component dealcoholized silicone rubber

[0094] 60 parts of terminal hydroxyl polydimethylsiloxane with a viscosity of 80000 mP·s at 23°C, 40 parts of terminal hydroxyl polydimethylsiloxane with a viscosity of 20000 mP·s at 23°C, 120 parts of nano calcium carbonate CCS-23 powder, and 5 parts of dimethylsilane with a viscosity of 350 mP·s at 23°C were mixed evenly, heated to 150°C for dehydration for 3 hours, cooled, added with 5 parts of adamantane-modified silane coupling agent, 0.5 parts of N-cyclohexyl-γ-aminopropylmethyldimethoxysilane, 0.5 parts of bis(3-trimethoxysilylpropyl)amine and 3 parts of 1,3-propanedioxytitanium bis(ethyl acetoacetate) (acetylacetone), mixed evenly, and the single-component dealcoholized silicone rubber was obtained.

[0095] Example 2

[0096] 1. Preparation of adamantane-modified silane coupling agent

[0097]

[0098] The difference from Example 1 is that adamantane-1,3-diol is used instead of adamantane-1-ol, and the added amount is 0.05 mol. The other raw materials, amounts used and preparation method are the same as those in Example 1.

[0099] 2. Preparation of single-component dealcoholized silicone rubber

[0100] The difference from Example 1 is that the adamantane-modified silane coupling agent prepared in Example 2 is used to replace the adamantane-modified silane coupling agent in Example 1, and other raw materials, amounts used and preparation methods are the same as those in Example 1.

[0101] Example 3

[0102] 1. Preparation of adamantane-modified silane coupling agent

[0103]

[0104] The difference from Example 1 is that adamantane-1,3,5,7-tetraol is used instead of adamantane-1-ol, and the added amount is 0.02 mol. Other raw materials, amounts used, and preparation methods are the same as those in Example 1.

[0105] 2. Preparation of single-component dealcoholized silicone rubber

[0106] The difference from Example 1 is that the adamantane-modified silane coupling agent prepared in Example 3 is used to replace the adamantane-modified silane coupling agent in Example 1, and other raw materials, amounts used and preparation methods are the same as those in Example 1.

[0107] Example 4

[0108] 1. Preparation of adamantane-modified silane coupling agent

[0109] The difference from Example 1 is that n in the modifier is 30, Y 1 OCH 3 , Y 2 OCH 3 The other raw materials, dosages and preparation methods are the same as those in Example 1.

[0110] 2. Preparation of single-component dealcoholized silicone rubber

[0111] The difference from Example 1 is that the adamantane-modified silane coupling agent prepared in Example 4 is used to replace the adamantane-modified silane coupling agent in Example 1, and other raw materials, amounts used and preparation methods are the same as those in Example 1.

[0112] Example 5

[0113] 1. Preparation of adamantane-modified silane coupling agent

[0114] The difference from Example 1 is that n in the modifier is 10, Y 1 OCH 3 , Y 2 -CH 3 The other raw materials, dosages and preparation methods are the same as those in Example 1.

[0115] 2. Preparation of single-component dealcoholized silicone rubber

[0116] The difference from Example 1 is that the adamantane-modified silane coupling agent prepared in Example 6 is used to replace the adamantane-modified silane coupling agent in Example 1, and other raw materials, amounts used and preparation methods are the same as those in Example 1.

[0117] Example 6

[0118] 1. Preparation of adamantane-modified silane coupling agent

[0119] The difference from Example 1 is that an equal amount of trimethyl(methylcyclopentadienyl)platinum(IV) is used instead of bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum. Other raw materials, amounts used and preparation methods are the same as those in Example 1.

[0120] 2. Preparation of single-component dealcoholized silicone rubber

[0121] The difference from Example 1 is that the adamantane-modified silane coupling agent prepared in Example 7 is used to replace the adamantane-modified silane coupling agent in Example 1, and other raw materials, amounts used and preparation methods are the same as those in Example 1.

[0122] Example 7

[0123] 1. The preparation of adamantane-modified silane coupling agent is the same as in Example 1.

[0124] 2. Preparation of single-component dealcoholized silicone rubber

[0125] The difference from Example 1 is that the added amount of the adamantane-modified silane coupling agent is 15 parts, and the other raw materials, amounts and preparation methods are the same as those in Example 1.

[0126] Example 8

[0127] 1. The preparation of adamantane-modified silane coupling agent is the same as in Example 1.

[0128] 2. Preparation of single-component dealcoholized silicone rubber

[0129] 100 parts of alkoxy-terminated polydimethylsiloxane with a viscosity of 20000 mP·s at 23°C, 80 parts of nano-calcium carbonate CCS-25 powder, and 10 parts of dimethyl silicone oil with a viscosity of 350 mP·s at 23°C were mixed evenly, and then dehydrated at 150°C for 3 hours. After cooling, 12 parts of R812 fumed silica were added and dispersed evenly, and then 4 parts of adamantane-modified silane coupling agent, 0.5 parts of γ-methacryloxypropyltrimethoxysilane, and 0.8 parts of 1,3-propanedioxytitanium bis(ethyl acetoacetate) (acetylacetone) were added, mixed evenly, and a single-component dealcoholized silicone rubber was obtained by discharging the material;

[0130] Comparative Example 1

[0131] The one-component dealcoholized silicone rubber provided in this comparative example is different from that in Example 1 in that methyltrimethoxysilane is used in equal parts by weight to replace the adamantane-modified silane coupling agent, and other raw materials, amounts used, and preparation methods are the same as those in Example 1.

[0132] Comparative Example 2

[0133] The one-component dealcoholized silicone rubber provided in this comparative example is different from that in Example 1 in that phenyltrimethoxysilane is used in equal parts by weight to replace the adamantane-modified silane coupling agent, and other raw materials, amounts used, and preparation methods are the same as those in Example 1.

[0134] Comparative Example 3

[0135] The one-component dealcoholized silicone rubber provided in this comparative example is different from that in Example 1 in that an equal weight portion of methyltrimethoxysilane oligomer is used to replace the adamantane-modified silane coupling agent, and other raw materials, amounts used, and preparation methods are the same as those in Example 1.

[0136] Performance Testing

[0137] The one-component dealcoholized silicone rubber obtained in the above examples and comparative examples was subjected to sample preparation and sample curing under the same conditions, and then the following performance tests were performed:

[0138] Surface drying time: The surface drying time is measured by the finger touch method according to GB / T 13477.5-2002B;

[0139] Tensile strength and elongation at break: The tensile strength and elongation at break after vulcanization for 168 hours at room temperature were measured according to GB / T 528-2009.

[0140] The results are shown in Table 1.

[0141] Table 1

[0142]

[0143]

[0144] It can be seen from Table 1 that the cross-linking reaction is greatly affected by the molecular shielding effect. The stronger the steric effect provided by the cross-linking agent group, the more the cross-linking points are shielded, which will lead to a decrease in the strength of the silicone rubber and an increase in the elongation. Comparative Example 1 uses conventional methyltrimethoxysilane as a cross-linking agent, and the tensile strength and elongation at break of the obtained silicone rubber are not ideal; Comparative Example 2 replaces the methyltrimethoxysilane in Comparative Example 1 with phenyltrimethoxysilane. The phenyl group has a greater spatial steric hindrance than the methyl group, and the cross-linking reaction shielding effect is stronger, and the cross-linking points are reduced, resulting in a significant decrease in the strength of the obtained silicone rubber and a significant increase in the elongation; Comparative Example 3 uses methylmethoxysilane oligomers to replace the methyltrimethoxysilane in Comparative Example 1, which increases the local cross-linking density around the cross-linking points, forms a cross-linking network faster, shortens the surface drying time of the obtained silicone rubber, and increases the tensile strength, but the cross-linking density is uneven, resulting in a decrease in elongation. It can be seen that it is difficult for existing silane coupling agents to simultaneously improve the tensile strength and elongation at break of silicone rubber.

[0145] In Examples 1-8, the methyltrimethoxysilane in Comparative Example 1 was replaced with the adamantane-modified silane coupling agent prepared by the present invention, and the tensile strength and elongation at break of the obtained silicone rubber were significantly improved. This may be because the adamantane group has a large steric hindrance, a stable internal hollow structure, and a strong shielding effect, which can improve the elongation; at the same time, the multiple active hydrogens on the adamantane group can form more hydrogen bonds with polysiloxane; the adamantane group has a rigid cage structure and a large specific surface area, which can play a reinforcing effect similar to silica. Therefore, under the combined effect of various factors, it is shown that the tensile strength and elongation of the obtained silicone rubber can be improved at the same time.

[0146] Among them, the number of hydroxyl groups in the adamantane used in Examples 1-3 is different, that is, the number of siloxy groups in the adamantane-modified silane coupling agent is different. It can be seen from the data in the table that the crosslinking points provided by the adamantane-modified silane coupling agent increase, and the time to form a crosslinked network is shortened, which is manifested as the surface drying time of the obtained silicone rubber becomes shorter with the increase of crosslinking points, and the tensile strength increases with the increase of crosslinking points; and it is found that, thanks to the three-dimensional cage structure of adamantane, the reactive siloxane groups are three-dimensionally distributed around the adamantane, which is different from the linear methyltrimethoxysilane oligomer (Comparative Example 3). With the increase of crosslinking density, the elongation of the silicone rubber is not only not reduced, but further significantly improved. The silicone rubber of Example 3 has a relatively higher tensile strength and the highest elongation at break, and has the lowest surface drying time, and its comprehensive performance is the best.

[0147] Compared with Example 1, Example 4 adds a flexible siloxane segment between adamantane and alkoxy, which weakens the intermolecular force, increases the activity space between polymer molecular chains, reduces the tensile strength, and slightly improves the elongation at break.

[0148] In Example 5, compared with Example 1, the trimethoxysilane-terminated modifier is replaced with a dimethoxy-terminated modifier, the end group hydrolysis activity is significantly reduced, the crosslinking density is reduced, and the surface drying time is significantly increased, which will affect the construction efficiency; the end group is changed from trimethoxy to dimethoxy, the crosslinking degree is reduced, the modulus is reduced, and the elongation at break is increased; at the same time, the steric hindrance is reduced, the crosslinking is more sufficient, and the tensile strength is also slightly improved.

[0149] Compared with Example 1, Example 6 replaces the catalyst for catalyzing the vinyl addition reaction, which has little effect on the final properties of the obtained silicone rubber.

[0150] In Example 7, compared with Example 1, the amount of adamantane-modified silane coupling agent added was increased to 15 parts, and the tensile strength was further improved, but the elongation at break was decreased and the surface drying time was increased.

[0151] Example 8 uses a filler combination of nano-calcium carbonate and fumed silica in combination with an adamantane-modified silane coupling agent. The three have a synergistic reinforcing effect, which can further significantly improve the tensile strength of the resulting silicone rubber and further improve the elongation, but the surface drying time will increase.

[0152] 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.

[0153] 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 adamantane-modified silane coupling agent, characterized in that: It has the following structure: wherein each X is independently selected from: -H, -OH and -R; Each R is independently selected from: n is 0 or an integer greater than 0; Y1 is -OCH3 or -OCH2CH3, and Y2 is -OCH3, -OCH2CH3, or -CH3.

2. The adamantane-modified silane coupling agent according to claim 1, characterized in that: All X are hydrogen; or, one X is hydrogen and two X are R; or, two X are hydrogen and one X is R; or, all three X are R.

3. The adamantane-modified silane coupling agent according to claim 1 or 2, characterized in that: n is an integer between 0 and 50, preferably an integer between 5 and 30, and more preferably an integer between 8 and 15; And / or, Y1 is -OCH3, and Y2 is -OCH3 or -CH3.

4. An adamantane-modified silane coupling agent, characterized in that: It is obtained by reacting adamantane alcohol with tetramethyldivinyldisilazane and a modifier in sequence; The structural formula of the modifier is: Wherein, n is 0 or an integer greater than 0; Y1 is -OCH3 or -OCH2CH3, and Y2 is -OCH3, -OCH2CH3, or -CH3.

5. The adamantane-modified silane coupling agent according to claim 4, characterized in that: The molar ratio of the hydroxyl group in the adamantane alcohol to the tetramethyldivinyldisilazane and the modifier is 1:(0.5-20):(0.8-2), preferably 1:(1-5):(1-1.5); and / or, the adamantane alcohol is selected from a combination of one or more of 1-adamantanol, adamantane-1,3-diol, adamantane-1,3,5-triol, adamantane-1,3,5,7-tetraol and 1-adamantanethanol; and / or, n is an integer between 0 and 50, preferably an integer between 5 and 30, more preferably an integer between 8 and 15; And / or, Y1 is -OCH3, and Y2 is -OCH3 or -CH3.

6. A method for preparing the adamantane-modified silane coupling agent according to any one of claims 1 to 5, characterized in that: The steps include: (1) reacting the adamantane alcohol with tetramethyldivinyldisilazane to obtain an intermediate product; (2) the intermediate product reacts with the modifier under the action of a platinum catalyst to obtain the adamantane-modified silane coupling agent; Preferably, the platinum catalyst is selected from at least one of a platinum-vinyl complex and a platinum-alkyne complex, preferably bis(1,3-divinyl-1,1,3,3-tetramethyldisiloxane)platinum(0) and / or trimethyl(methylcyclopentadienyl)platinum(IV); Preferably, the reaction temperature in step (1) is 40°C to 90°C, and the reaction time is 0.5h to 8h; Preferably, the reaction temperature in step (2) is 10°C to 100°C, and the reaction time is 0.5h to 5h.

7. Use of the adamantane-modified silane coupling agent according to any one of claims 1 to 5 as a crosslinking agent in the preparation of a one-component dealcoholized silicone rubber.

8. A one-component dealcoholized silicone rubber, characterized in that: The crosslinking agent is the adamantane-modified silane coupling agent described in any one of claims 1 to 5.

9. The one-component dealcoholized silicone rubber according to claim 8, characterized in that: The one-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight: Preferably, the single-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight: Preferably, the single-component dealcoholized silicone rubber is prepared from raw materials including the following components in parts by weight: Preferably, the base polymer is a hydroxy-terminated polydimethylsiloxane or an alkoxy-terminated polydimethylsiloxane, and the viscosity of the base polymer at 23° C. is preferably 1500 mP·s to 80000 mP·s, more preferably 10000 mP·s to 80000 mP·s, more preferably 10000 mP·s to 50000 mP·s, more preferably 18000 mP·s to 22000 mP·s; Preferably, the filler is selected from one or more combinations of fumed silica, nano-calcium carbonate, titanium dioxide, kaolin, diatomaceous earth, silica powder, mica and barium sulfate; Preferably, the plasticizer is selected from at least one of dimethyl silicone oil, methoxy silicone oil, MDT silicone oil and hydroxy silicone oil, and the viscosity of the plasticizer at 23° C. is preferably 50 mP·s to 1000 mP·s, more preferably 300 mP·s to 500 mP·s; Preferably, the coupling agent is selected from one or more combinations of 3-aminopropyltrimethoxysilane, N-cyclohexyl-γ-aminopropylmethyldimethoxysilane, bis(3-trimethoxysilylpropyl)amine, aminosilane oligomer, cyanopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane and 3-ureidopropyltriethoxysilane; Preferably, the catalyst is one or more combinations of organotin catalysts and phthalate catalysts; Preferably, the organotin catalyst is at least one selected from dibutyltin dilaurate, dibutyltin diacetate, dimethyltin dineuteroate and dibutyltin diacetylacetonate; Preferably, the phthalate catalyst is at least one selected from tetra-n-butyl titanate, polytetra-n-butyl titanate, 2-ethylhexyloxy titanate, 1,3-propylenedioxytitanium bis(ethyl acetoacetate) (acetylacetone) and diisopropyl bis(ethyl acetoacetate) titanate.

10. A method for preparing the one-component dealcoholized silicone rubber according to claim 9, characterized in that: The method comprises the following steps: mixing the base polymer, filler and plasticizer uniformly, heating and dehydrating the mixture, adding the crosslinking agent, coupling agent and catalyst after cooling, and mixing the mixture uniformly to obtain the single-component dealcoholized silicone rubber.

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