Anti-aging sealing strip material and preparation method thereof

Abstract

The invention discloses an anti-aging sealing strip material and a preparation method thereof.The anti-aging sealing strip material is prepared by enabling chlorine atom sites on pretreated silicone rubber and alcoholic hydroxyl groups on a modified additive to react under the action of triethylamine of the pretreated silicone rubber and the modified additive, and the anti-aging sealing strip material contains a hindered phenol structure, so that the anti-aging performance of the anti-aging sealing strip material is improved, and the service life of the anti-aging sealing strip material is prolonged. The hindered phenol structure can capture free radicals and convert peroxy free radicals into hydroperoxide so as to prevent linkage oxidation reaction caused by the free radicals, the molecular structure contains a large number of unsaturated double bonds, the unsaturated double bonds are of flexible structures, the electron cloud density is low, the van der Waals force between molecules can be weakened, and meanwhile, due to the existence of the polyrotaxane structure, the molecular structure can be used for preparing the polymer. According to the present invention, with the introduction of the disulfide bond and the elastomer structure, the material does not deform under the long-term compression state so as to ensure the sealing effect;

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber material preparation, and in particular to an aging-resistant sealing strip material and a preparation method thereof. Background Art

[0002] Silicone rubber is one of the most important products in silicone materials. Silicone rubber is mainly composed of linear polysiloxane (or base rubber, raw rubber), crosslinking agent, catalyst and other additives. All components can be evenly mixed to form a mixed rubber. Under certain conditions, the mixed rubber is crosslinked (or vulcanized, cured) to change from the initial high-viscosity plastic state to an elastic state, that is, a vulcanized rubber with a three-dimensional network cross-linked structure is obtained. Silicone rubber base rubber is a type of high molecular weight linear polydiorganosiloxane, which is a type of linear high molecular weight polymer formed by polymerization of organic cyclosiloxane monomers in the presence of acid or base catalysts after equilibrium reaction. The main chain of the base rubber is composed of repeated Si-O bonds, and the side chain is composed of organic substituents connected by SiC bonds. Therefore, the base rubber has both organic and inorganic properties. Silicone rubber materials are often used in sealing materials, but they are prone to permanent deformation under long-term compression, and their flexibility is reduced in low temperature environments, making it impossible to achieve normal sealing effects. Summary of the invention

[0003] The purpose of the present invention is to provide an aging-resistant sealing strip material and a preparation method thereof, which solves the problem that the current silicone rubber sealing strip material has poor low-temperature resistance, deforms after long-term compression, and has reduced sealing effect.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A method for preparing an aging-resistant sealing strip material comprises the following steps:

[0006] Step A1: octamethylcyclotetrasiloxane and tetramethylammonium hydroxide are uniformly mixed, nitrogen is introduced for protection, and the reaction is carried out for 3-5 hours at a speed of 120-150 r / min and a temperature of 120-125° C. to obtain an alkali-gel catalyst, allyl alcohol is dissolved in chloroform, and 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine are added under stirring at a speed of 120-150 r / min and a temperature of 20-25° C., and the temperature is raised to 40-50° C. and the reaction is carried out for 20-25 hours to obtain an intermediate 1;

[0007] Step A2: The intermediate 1, tetramethylcyclotetrasiloxane, chloroplatinic acid and DMF are mixed uniformly, nitrogen is introduced for protection, and the reaction is carried out for 4-6 hours at a speed of 200-300 r / min and a temperature of 75-80° C. to obtain a modifier; octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane and the modifier are mixed uniformly, nitrogen is introduced for protection, and the reaction is carried out for 3-5 hours at a speed of 120-150 r / min and a temperature of 110-115° C. to obtain a pretreated silicone rubber;

[0008] Step A3: The additive, ethanolamine and DMF are mixed evenly, and reacted for 6-8 hours at a rotation speed of 200-300 r / min and a temperature of 60-70°C to obtain a modified additive. The pretreated silicone rubber is dissolved in chlorobenzene, and the modified additive and triethylamine are added under stirring at a rotation speed of 60-80 r / min and a temperature of 30-40°C, and the reaction is carried out for 20-25 hours. The chlorobenzene is removed to obtain an aging-resistant sealing strip material.

[0009] Furthermore, the mass ratio of octamethylcyclotetrasiloxane and tetramethylammonium hydroxide described in step A1 is 50:1, and the molar ratio of allyl alcohol, 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine is 1:1:1.1.

[0010] Further, the molar ratio of the intermediate 1 and tetramethylcyclotetrasiloxane described in step A2 is 4:1, the amount of chloroplatinic acid used is 1‰ of the mass of tetramethylcyclotetrasiloxane, and the amount ratio of octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane, modifier, base catalyst and hexadecylheptasiloxane is 80mol:20mol:15mol:9g:60mmol.

[0011] Furthermore, the molar ratio of the aldehyde group and ethanolamine on the additive in step A3 is 1:1, the mass ratio of the pretreated silicone rubber and the modified additive is 5:1, and the amount of triethylamine used is 1% of the total mass of the pretreated rubber and the modified additive.

[0012] Further, the additive is prepared by the following steps:

[0013] Step B1: β-cyclodextrin, amino-terminated polybutadiene and ethanol are mixed, and ultrasonically treated for 6-8 hours at a frequency of 20-30 kHz to obtain a reinforcing monomer, and bis(4-hydroxyphenyl) disulfide, triethylamine and tetrahydrofuran are mixed evenly, and 3-chloropropyldimethylethoxysilane is added under stirring at a speed of 120-150 r / min and a temperature of 0° C., and the mixture is reacted for 4-6 hours to obtain an intermediate 2;

[0014] Step B2: Mix intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene and deionized water, react for 3-5 hours at a speed of 120-150 r / min and a temperature of 80-85° C., add vinyldimethylchlorosilane, raise the temperature to 100° C., and continue to react for 2-3 hours to obtain intermediate 3, mix intermediate 3, 2-mercaptoethanol, benzophenone and DMF uniformly, react for 30-40 minutes at a speed of 60-80 r / min and 365 nm ultraviolet light irradiation to obtain a modified monomer;

[0015] Step B3: uniformly mix the reinforcing monomer, the modifying monomer and DMF, introduce nitrogen protection, stir and add isophorone diisocyanate at a speed of 120-150 r / min and a temperature of 60-65° C., react for 3-5 hours, then heat to 75-80° C., add N-(4-hydroxyphenyl)maleimide and dibutyltin dilaurate, and react for 2-3 hours to obtain an elastomer, uniformly mix the elastomer, 2-iodoacylbenzoic acid and DMF, and react for 20-25 hours at a speed of 60-80 r / min and a temperature of 25-30° C. to obtain an additive.

[0016] Furthermore, the amount ratio of β-cyclodextrin, amino-terminated polybutadiene and ethanol in step B1 is 5g:1g:200mL, the molecular weight of amino-terminated polybutadiene is 2000, and the molar ratio of bis(4-hydroxyphenyl) disulfide, triethylamine and 3-chloropropyldimethylethoxysilane is 1:1.1:1.

[0017] Further, the amount ratio of the intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene, deionized water and vinyldimethylchlorosilane described in step B2 is 4mmo l:20mmo l:0.01g:25mL:2mL:5mmo l, the molar ratio of the double bond on the intermediate 3 and 2-mercaptoethanol is 1:1, and the amount of benzophenone is 5‰ of the mass of 2-mercaptoethanol.

[0018] Furthermore, the mass ratio of the reinforcing monomer, the modifying monomer, isophorone diisocyanate and N-(4-hydroxyphenyl)maleimide described in step B3 is 12:50:28:5, the amount of dibutyltin dilaurate is 2‰ of the mass of N-(4-hydroxyphenyl)maleimide, and the mass ratio of the elastomer to 2-iodoacylbenzoic acid is 10:1.

[0019] Beneficial effects of the invention: The present application discloses an aging-resistant sealing strip material, which uses octamethylcyclotetrasiloxane and tetramethylammonium hydroxide as raw materials to prepare an alkali-gel catalyst, reacts allyl alcohol with 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride, so that the alcohol hydroxyl group on the allyl alcohol reacts with the acyl chloride on the 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride to prepare an intermediate 1, and reacts the intermediate 1 with tetramethylcyclotetrasiloxane, so that the double bond on the intermediate 1 reacts with the S on the tetramethylcyclotetrasiloxane. iH bond reaction to obtain a modifier, octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane and the modifier are ring-opening polymerized, and then capped with hexadecylheptasiloxane to obtain a pretreated silicone rubber, the additive is reacted with ethanolamine to make the aldehyde group on the additive react with the amino group on the ethanolamine to obtain a modified additive, the pretreated silicone rubber and the modified additive are reacted under the action of triethylamine to make the chlorine atom site on the pretreated silicone rubber react with the alcohol hydroxyl group on the modified additive to obtain an aging-resistant sealing strip material.

[0020] The additive is prepared by reacting β-cyclodextrin with terminal amino polybutadiene to form a polyrotaxane structure, and preparing a reinforcing monomer. Bis(4-hydroxyphenyl) disulfide and 3-chloropropyldimethylethoxysilane are reacted under the action of triethylamine so that the phenolic hydroxyl group on the bis(4-hydroxyphenyl) disulfide reacts with the chlorine atom site on the 3-chloropropyldimethylethoxysilane to prepare an intermediate 2. Intermediate 2 and dimethyldimethoxysilane are hydrolyzed and condensed, and then the intermediate 3 is capped with vinyldimethylchlorosilane to prepare an intermediate 3. Intermediate 3 and 2-mercaptoethanol are photo-irradiated to react so that the double bond on the intermediate 3 reacts with the thiol group on the 2-mercaptoethanol to prepare a modified monomer. The reinforcing monomer, the modified monomer and isophorone diisocyanate are reacted to form a polyurethane prepolymer, and then the prepolymer is capped with N-(4-hydroxyphenyl)maleimide. The elastomer is treated with 2-iodoacylbenzoic acid so that the hydroxyl group on the elastomer is converted into an aldehyde group to prepare the additive.

[0021] The aging-resistant sealing strip material contains a hindered phenol structure, which can capture free radicals and convert peroxy radicals into hydroperoxides, thereby preventing the chain oxidation reaction caused by free radicals. The molecular structure contains a large number of unsaturated double bonds, which are flexible structures with low electron cloud density, and can weaken the van der Waals forces between molecules. At the same time, the presence of the polyrotaxane structure allows relative sliding between the pretreated silicone rubber molecular chains and the additive molecules, ensuring that the molecules are easier to slide under low temperature conditions and improving the low-temperature resistance of the material. At the same time, the introduction of disulfide bonds and elastomer structures prevents the material from deforming under long-term compression, thereby ensuring the sealing effect. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] A method for preparing an aging-resistant sealing strip material comprises the following steps:

[0025] Step A1: octamethylcyclotetrasiloxane and tetramethylammonium hydroxide are mixed uniformly, nitrogen is introduced for protection, and the reaction is carried out at a speed of 120 r / min and a temperature of 120° C. for 3 hours to obtain an alkali-gel catalyst, allyl alcohol is dissolved in chloroform, and 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine are added under stirring at a speed of 120 r / min and a temperature of 20° C., the temperature is raised to 40° C., and the reaction is carried out for 20 hours to obtain an intermediate 1;

[0026] Step A2: The intermediate 1, tetramethylcyclotetrasiloxane, chloroplatinic acid and DMF are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 4 hours at a speed of 200 r / min and a temperature of 75° C. to obtain a modifier; octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane and the modifier are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 3 hours at a speed of 120 r / min and a temperature of 110° C. to obtain a pretreated silicone rubber;

[0027] Step A3: The additive, ethanolamine and DMF are mixed evenly, and reacted for 6 hours at a speed of 200 r / min and a temperature of 60°C to obtain a modified additive. The pretreated silicone rubber is dissolved in chlorobenzene, and the modified additive and triethylamine are added under stirring at a speed of 60 r / min and a temperature of 30°C, and the reaction is carried out for 20 hours. Chlorobenzene is removed to obtain an aging-resistant sealing strip material.

[0028] The mass ratio of octamethylcyclotetrasiloxane and tetramethylammonium hydroxide described in step A1 is 50:1, and the molar ratio of allyl alcohol, 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine is 1:1:1.1.

[0029] The molar ratio of intermediate 1 and tetramethylcyclotetrasiloxane described in step A2 is 4:1, the amount of chloroplatinic acid used is 1‰ of the mass of tetramethylcyclotetrasiloxane, and the amount ratio of octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane, modifier, base catalyst and hexadecylheptasiloxane is 80mol:20mol:15mol:9g:60mmol.

[0030] The molar ratio of the aldehyde group and ethanolamine on the additive in step A3 is 1:1, the mass ratio of the pretreated silicone rubber and the modified additive is 5:1, and the amount of triethylamine used is 1% of the total mass of the pretreated rubber and the modified additive.

[0031] The additive is prepared by the following steps:

[0032] Step B1: β-cyclodextrin, amino-terminated polybutadiene and ethanol were mixed, and ultrasonically treated for 6 hours at a frequency of 20 kHz to obtain a reinforcing monomer. Bis(4-hydroxyphenyl) disulfide, triethylamine and tetrahydrofuran were mixed evenly, and 3-chloropropyldimethylethoxysilane was added under stirring at a speed of 120 r / min and a temperature of 0°C, and the mixture was reacted for 4 hours to obtain an intermediate 2.

[0033] Step B2: Intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene and deionized water were mixed, and the reaction was carried out at a speed of 120 r / min and a temperature of 80° C. for 3 h, vinyldimethylchlorosilane was added, the temperature was raised to 100° C., and the reaction was continued for 2 h to obtain intermediate 3, and intermediate 3, 2-mercaptoethanol, benzophenone and DMF were mixed uniformly, and the reaction was carried out at a speed of 60 r / min and 365 nm ultraviolet light irradiation for 30 min to obtain a modified monomer;

[0034] Step B3: The reinforcing monomer, the modifying monomer and DMF are mixed evenly, nitrogen is introduced for protection, and isophorone diisocyanate is added under the conditions of a rotation speed of 120 r / min and a temperature of 60°C. After reacting for 3 hours, the temperature is raised to 75°C, N-(4-hydroxyphenyl)maleimide and dibutyltin dilaurate are added, and the reaction is carried out for 2 hours to obtain an elastomer. The elastomer, 2-iodoacylbenzoic acid and DMF are mixed evenly, and the reaction is carried out for 20 hours at a rotation speed of 60 r / min and a temperature of 25°C to obtain an additive.

[0035] The amount ratio of β-cyclodextrin, amino-terminated polybutadiene and ethanol in step B1 is 5g:1g:200mL, the molecular weight of amino-terminated polybutadiene is 2000, and the molar ratio of bis(4-hydroxyphenyl) disulfide, triethylamine and 3-chloropropyldimethylethoxysilane is 1:1.1:1.

[0036] The amount ratio of intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene, deionized water and vinyldimethylchlorosilane described in step B2 is 4mmo l:20mmo l:0.01g:25mL:2mL:5mmo l, the molar ratio of the double bond on intermediate 3 and 2-mercaptoethanol is 1:1, and the amount of benzophenone is 5‰ of the mass of 2-mercaptoethanol.

[0037] The mass ratio of the reinforcing monomer, the modifying monomer, isophorone diisocyanate and N-(4-hydroxyphenyl)maleimide described in step B3 is 12:50:28:5, the amount of dibutyltin dilaurate is 2‰ of the mass of N-(4-hydroxyphenyl)maleimide, and the mass ratio of the elastomer and 2-iodoacylbenzoic acid is 10:1.

[0038] Example 2

[0039] A method for preparing an aging-resistant sealing strip material comprises the following steps:

[0040] Step A1: octamethylcyclotetrasiloxane and tetramethylammonium hydroxide are mixed uniformly, nitrogen is introduced for protection, and the reaction is carried out for 4 hours at a speed of 120 r / min and a temperature of 125° C. to obtain an alkali-gel catalyst, allyl alcohol is dissolved in chloroform, and 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine are added under stirring at a speed of 120 r / min and a temperature of 25° C., and the temperature is raised to 45° C. and the reaction is carried out for 25 hours to obtain an intermediate 1;

[0041] Step A2: The intermediate 1, tetramethylcyclotetrasiloxane, chloroplatinic acid and DMF are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 5 hours at a speed of 200 r / min and a temperature of 80° C. to obtain a modifier; octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane and the modifier are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 4 hours at a speed of 120 r / min and a temperature of 115° C. to obtain a pretreated silicone rubber;

[0042] Step A3: The additive, ethanolamine and DMF are mixed evenly, and reacted for 7 hours at a speed of 200 r / min and a temperature of 65°C to obtain a modified additive. The pretreated silicone rubber is dissolved in chlorobenzene, and the modified additive and triethylamine are added under stirring at a speed of 80 r / min and a temperature of 35°C, and the reaction is carried out for 23 hours. Chlorobenzene is removed to obtain an aging-resistant sealing strip material.

[0043] The mass ratio of octamethylcyclotetrasiloxane and tetramethylammonium hydroxide described in step A1 is 50:1, and the molar ratio of allyl alcohol, 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine is 1:1:1.1.

[0044] The molar ratio of intermediate 1 and tetramethylcyclotetrasiloxane described in step A2 is 4:1, the amount of chloroplatinic acid used is 1‰ of the mass of tetramethylcyclotetrasiloxane, and the amount ratio of octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane, modifier, base catalyst and hexadecylheptasiloxane is 80mol:20mol:15mol:9g:60mmol.

[0045] The molar ratio of the aldehyde group and ethanolamine on the additive in step A3 is 1:1, the mass ratio of the pretreated silicone rubber and the modified additive is 5:1, and the amount of triethylamine used is 1% of the total mass of the pretreated rubber and the modified additive.

[0046] The additive is prepared by the following steps:

[0047] Step B1: β-cyclodextrin, amino-terminated polybutadiene and ethanol were mixed, and ultrasonically treated for 7 hours at a frequency of 25 kHz to obtain a reinforcing monomer. Bis(4-hydroxyphenyl) disulfide, triethylamine and tetrahydrofuran were mixed evenly, and 3-chloropropyldimethylethoxysilane was added under stirring at a speed of 120 r / min and a temperature of 0°C, and the mixture was reacted for 5 hours to obtain an intermediate 2.

[0048] Step B2: Intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene and deionized water were mixed, and the reaction was carried out for 4 hours at a speed of 120 r / min and a temperature of 85° C., vinyldimethylchlorosilane was added, the temperature was raised to 100° C., and the reaction was continued for 3 hours to obtain intermediate 3, and intermediate 3, 2-mercaptoethanol, benzophenone and DMF were mixed uniformly, and the reaction was carried out for 35 minutes at a speed of 80 r / min and 365 nm ultraviolet light irradiation to obtain a modified monomer;

[0049] Step B3: The reinforcing monomer, the modifying monomer and DMF are mixed evenly, nitrogen is introduced for protection, and isophorone diisocyanate is added under the conditions of a rotation speed of 120 r / min and a temperature of 65°C. After reacting for 4 hours, the temperature is raised to 80°C, N-(4-hydroxyphenyl)maleimide and dibutyltin dilaurate are added, and the reaction is carried out for 2 hours to obtain an elastomer. The elastomer, 2-iodoacylbenzoic acid and DMF are mixed evenly, and the reaction is carried out for 20 hours at a rotation speed of 80 r / min and a temperature of 30°C to obtain an additive.

[0050] The amount ratio of β-cyclodextrin, amino-terminated polybutadiene and ethanol in step B1 is 5g:1g:200mL, the molecular weight of amino-terminated polybutadiene is 2000, and the molar ratio of bis(4-hydroxyphenyl) disulfide, triethylamine and 3-chloropropyldimethylethoxysilane is 1:1.1:1.

[0051] The amount ratio of intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene, deionized water and vinyldimethylchlorosilane described in step B2 is 4mmo l:20mmo l:0.01g:25mL:2mL:5mmo l, the molar ratio of the double bond on intermediate 3 and 2-mercaptoethanol is 1:1, and the amount of benzophenone is 5‰ of the mass of 2-mercaptoethanol.

[0052] The mass ratio of the reinforcing monomer, the modifying monomer, isophorone diisocyanate and N-(4-hydroxyphenyl)maleimide described in step B3 is 12:50:28:5, the amount of dibutyltin dilaurate is 2‰ of the mass of N-(4-hydroxyphenyl)maleimide, and the mass ratio of the elastomer and 2-iodoacylbenzoic acid is 10:1.

[0053] Example 3

[0054] A method for preparing an aging-resistant sealing strip material comprises the following steps:

[0055] Step A1: octamethylcyclotetrasiloxane and tetramethylammonium hydroxide are uniformly mixed, nitrogen is introduced for protection, and the reaction is carried out for 5 hours at a speed of 150 r / min and a temperature of 125° C. to obtain an alkali-gel catalyst, allyl alcohol is dissolved in chloroform, and 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine are added under stirring at a speed of 150 r / min and a temperature of 25° C., and the temperature is raised to 50° C. and the reaction is carried out for 25 hours to obtain an intermediate 1;

[0056] Step A2: The intermediate 1, tetramethylcyclotetrasiloxane, chloroplatinic acid and DMF are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 6 hours at a speed of 300 r / min and a temperature of 80° C. to obtain a modifier; octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane and the modifier are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out at a speed of 150 r / min and a temperature of 115° C., and a base catalyst and hexamethylheptasiloxane are added to stir and react for 5 hours to obtain a pretreated silicone rubber;

[0057] Step A3: The additive, ethanolamine and DMF are mixed evenly, and reacted at a speed of 300 r / min and a temperature of 70°C for 8 hours to obtain a modified additive. The pretreated silicone rubber is dissolved in chlorobenzene, and the modified additive and triethylamine are added under stirring at a speed of 80 r / min and a temperature of 40°C, and the reaction is carried out for 25 hours. Chlorobenzene is removed to obtain an aging-resistant sealing strip material.

[0058] The mass ratio of octamethylcyclotetrasiloxane and tetramethylammonium hydroxide described in step A1 is 50:1, and the molar ratio of allyl alcohol, 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine is 1:1:1.1.

[0059] The molar ratio of intermediate 1 and tetramethylcyclotetrasiloxane described in step A2 is 4:1, the amount of chloroplatinic acid used is 1‰ of the mass of tetramethylcyclotetrasiloxane, and the amount ratio of octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane, modifier, base catalyst and hexadecylheptasiloxane is 80mol:20mol:15mol:9g:60mmol.

[0060] The molar ratio of the aldehyde group and ethanolamine on the additive in step A3 is 1:1, the mass ratio of the pretreated silicone rubber and the modified additive is 5:1, and the amount of triethylamine used is 1% of the total mass of the pretreated rubber and the modified additive.

[0061] The additive is prepared by the following steps:

[0062] Step B1: β-cyclodextrin, amino-terminated polybutadiene and ethanol were mixed, and ultrasonically treated for 8 hours at a frequency of 30 kHz to obtain a reinforcing monomer. Bis(4-hydroxyphenyl) disulfide, triethylamine and tetrahydrofuran were mixed evenly, and 3-chloropropyldimethylethoxysilane was added under stirring at a speed of 150 r / min and a temperature of 0°C, and the mixture was reacted for 6 hours to obtain an intermediate 2.

[0063] Step B2: Intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene and deionized water were mixed, and the reaction was carried out at a speed of 150 r / min and a temperature of 85° C. for 5 h, vinyldimethylchlorosilane was added, the temperature was raised to 100° C., and the reaction was continued for 3 h to obtain intermediate 3, and intermediate 3, 2-mercaptoethanol, benzophenone and DMF were mixed uniformly, and the reaction was carried out at a speed of 80 r / min and 365 nm ultraviolet light irradiation for 40 min to obtain a modified monomer;

[0064] Step B3: The reinforcing monomer, the modifying monomer and DMF are mixed evenly, nitrogen is introduced for protection, and isophorone diisocyanate is added under the conditions of a rotation speed of 150 r / min and a temperature of 65°C. After reacting for 5 hours, the temperature is raised to 80°C, N-(4-hydroxyphenyl)maleimide and dibutyltin dilaurate are added, and the reaction is carried out for 3 hours to obtain an elastomer. The elastomer, 2-iodoacylbenzoic acid and DMF are mixed evenly, and the reaction is carried out for 25 hours at a rotation speed of 80 r / min and a temperature of 30°C to obtain an additive.

[0065] The amount ratio of β-cyclodextrin, amino-terminated polybutadiene and ethanol in step B1 is 5g:1g:200mL, the molecular weight of amino-terminated polybutadiene is 2000, and the molar ratio of bis(4-hydroxyphenyl) disulfide, triethylamine and 3-chloropropyldimethylethoxysilane is 1:1.1:1.

[0066] The amount ratio of intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene, deionized water and vinyldimethylchlorosilane described in step B2 is 4mmo l:20mmo l:0.01g:25mL:2mL:5mmo l, the molar ratio of the double bond on intermediate 3 and 2-mercaptoethanol is 1:1, and the amount of benzophenone is 5‰ of the mass of 2-mercaptoethanol.

[0067] The mass ratio of the reinforcing monomer, the modifying monomer, isophorone diisocyanate and N-(4-hydroxyphenyl)maleimide described in step B3 is 12:50:28:5, the amount of dibutyltin dilaurate is 2‰ of the mass of N-(4-hydroxyphenyl)maleimide, and the mass ratio of the elastomer and 2-iodoacylbenzoic acid is 10:1.

[0068] Comparative Example 1

[0069] Compared with Example 1, no modifier was added in this comparative example, and the remaining steps were the same.

[0070] Comparative Example 2

[0071] Compared with Example 1, this comparative example uses pretreated silicone rubber instead of sealing material, and the other steps are the same.

[0072] Comparative Example 3

[0073] Compared with Example 1, no modified monomer was added in this comparative example, and the remaining steps were the same.

[0074] The aging-resistant sealing strip materials obtained in Examples 1-3 and Comparative Examples 1-3 were made into dumbbell-shaped strips with a thickness of 2 mm and a width of 6 mm according to the standard of GB / T528-2009. The tensile speed was 500 mm / min, and the tensile strength was tested. Then, the strips were kept at a temperature of 150°C for 3 days, and the tensile strength was tested to calculate the decline rate. The elongation at break was tested at minus 70°C to calculate the decline rate. According to the standard of GB / T7759.1-2015, type A specimens were made to test the compression permanent deformation. The test results are shown in the following table.

[0075]

[0076] It can be seen from the above table that the present application has good aging resistance and low temperature resistance, and will not show obvious deformation after being compressed for a long time.

[0077] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. An aging-resistant sealing strip material and a preparation method thereof, characterized in that: The specific steps include: Step A1: octamethylcyclotetrasiloxane and tetramethylammonium hydroxide are uniformly mixed, nitrogen is introduced for protection, and the reaction is carried out to obtain an alkali-gel catalyst, allyl alcohol is dissolved in chloroform, 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine are added after stirring, and the temperature is raised for reaction to obtain an intermediate 1; Step A2: The intermediate 1, tetramethylcyclotetrasiloxane, chloroplatinic acid and DMF are uniformly mixed, nitrogen is introduced for protection, and a reaction is carried out to obtain a modifier; octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane and the modifier are uniformly mixed, nitrogen is introduced for protection, and a base catalyst and hexadecylheptasiloxane are added for stirring and a reaction is carried out to obtain a pretreated silicone rubber; Step A3: The additive, ethanolamine and DMF are mixed and reacted to obtain a modified additive, the pretreated silicone rubber is dissolved in chlorobenzene, stirred and the modified additive and triethylamine are added to react, chlorobenzene is removed, and an aging-resistant sealing strip material is obtained.

2. The aging-resistant sealing strip material and preparation method thereof according to claim 1, characterized in that: The mass ratio of octamethylcyclotetrasiloxane and tetramethylammonium hydroxide described in step A1 is 50:1, and the molar ratio of allyl alcohol, 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and triethylamine is 1:1:1.

1.

3. The aging-resistant sealing strip material and preparation method thereof according to claim 1, characterized in that: The molar ratio of the intermediate 1 and tetramethylcyclotetrasiloxane described in step A2 is 4:1, and the usage ratio of octamethylcyclotetrasiloxane, γ-chloropropylheptamethylcyclotetrasiloxane, modifier, base catalyst and hexadecylheptasiloxane is 80mol:20mol:15mol:9g:60mmol.

4. The aging-resistant sealing strip material and the preparation method thereof according to claim 1, characterized in that: The molar ratio of the aldehyde group and the ethanolamine on the additive described in step A3 is 1:1, and the mass ratio of the pretreated silicone rubber and the modified additive is 5:

1.

5. The aging-resistant sealing strip material and the preparation method thereof according to claim 1, characterized in that: The additive is prepared by the following steps: Step B1: β-cyclodextrin, amino-terminated polybutadiene and ethanol are mixed and ultrasonically treated to obtain a reinforcing monomer, bis(4-hydroxyphenyl) disulfide, triethylamine and tetrahydrofuran are mixed and stirred, and 3-chloropropyldimethylethoxysilane is added to react to obtain an intermediate 2; Step B2: Mixing intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene and deionized water for reaction, adding vinyldimethylsilyl chloride, heating to react, to obtain intermediate 3, mixing intermediate 3, 2-mercaptoethanol, benzophenone and DMF for reaction, to obtain a modified monomer; Step B3: uniformly mix the reinforcing monomer, the modifying monomer and DMF, introduce nitrogen protection, stir and add isophorone diisocyanate, react, heat up and add N-(4-hydroxyphenyl)maleimide and dibutyltin dilaurate, react to obtain an elastomer, mix the elastomer, 2-iodoacylbenzoic acid and DMF to obtain an additive.

6. The aging-resistant sealing strip material and the preparation method thereof according to claim 5, characterized in that: The amount ratio of β-cyclodextrin, terminal amino polybutadiene and ethanol in step B1 is 5g:1g:200mL, and the molar ratio of bis(4-hydroxyphenyl) disulfide, triethylamine and 3-chloropropyldimethylethoxysilane is 1:1.1:

1.

7. The aging-resistant sealing strip material and the preparation method thereof according to claim 5, characterized in that: The amount ratio of intermediate 2, dimethyldimethoxysilane, tetramethylammonium hydroxide, toluene, deionized water and vinyldimethylchlorosilane described in step B2 is 4mmol:20mmol:0.01g:25mL:2mL:5mmol, and the molar ratio of the double bond on intermediate 3 and 2-mercaptoethanol is 1:

1.

8. The aging-resistant sealing strip material and the preparation method thereof according to claim 5, characterized in that: The mass ratio of the reinforcing monomer, the modifying monomer, isophorone diisocyanate and N-(4-hydroxyphenyl)maleimide described in step B3 is 12:50:28:5, and the mass ratio of the elastomer and 2-iodoacylbenzoic acid is 10:

1.

9. An aging-resistant sealing strip material, characterized by: Prepared according to any one of the preparation methods described in claims 1-8.

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