CN117844440A - Double-component condensed organosilicon sealant and preparation method thereof - Google Patents

Abstract

The invention discloses a double-component condensed type organic silicon sealant and a preparation method thereof, wherein the organic silicon sealant consists of a component A and a component B, the component A is prepared from a base polymer, a modified filler, a functional filler and a plasticizer, the component B is prepared from a dispersing agent, a filler, a cross-linking agent, a catalyst and carbon black, and the modified filler is a metal oxide modified by a silane coupling agent. The double-component condensed type organic silicon sealant disclosed by the invention has the advantages of high storage stability and small performance fluctuation, the problems of uneven mixing, unbalanced mixing proportion and unbalanced design proportion of a sizing material are avoided, the prepared sizing material has low viscosity, high extrusion performance and high vulcanization speed, is more suitable for an automatic sizing process, and can be widely applied to sealing, bonding and protection in the fields of automobiles, electronic appliances, new energy sources, photovoltaics and the like.

Description

Double-component condensed organosilicon sealant and preparation method thereof

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a double-component condensed type organic silicon sealant and a preparation method thereof.

Background

The double-component condensed room temperature vulcanizing (RTV-2) organic silicon sealant is common RTV silicon rubber, and when in use, A, B two components are mixed according to a certain proportion, so that an elastomer with sealing, bonding and other functions can be formed by curing; the use is convenient, equipment such as heating and pressurizing is not needed, the vulcanization process is not exothermic, does not absorb heat and does not expand, the sizing material contains a proper amount of water, the simultaneous vulcanization of the inside and the surface can be realized, and the dependence on the change of the environmental humidity is low; the vulcanizing speed is high, the vulcanizing can be basically and completely performed only by 1-2 hours, the initial strength is high, the adhesive is more suitable for the adhesive sealing use in the industries of automatic production or short turnover time, and the adhesive is widely applied in the fields of automobiles, electronic appliances, power supplies, photovoltaics and the like. In recent years, RTV-2 two-component condensation type silicone sealants have been greatly developed.

At present, a commercial condensed RTV-2 organic silicon sealant is prepared by mixing hydroxyl-terminated polydimethylsiloxane (107 silicon rubber), a filler containing certain moisture, a functional filler and the like, and a component B is prepared by mainly using a plasticizer, a cross-linking agent, a silane coupling agent, a catalyst, a color paste and the like, wherein the volume ratio of a component A, B is generally 1 during construction use: 1 to 10:1, and mixing and preparing the components according to the design proportion. Therefore, in practical construction, to achieve the ratio to fully achieve the nominal performance of the sealant, the requirement on the metering precision of the mixing equipment is high, and the storage stability of A, B components is high and the performance fluctuation is low. However, compared with single-component room temperature vulcanized silicone rubber, the B component of the double-component sealant contains a large amount of highly active and easily hydrolyzed auxiliary agents (cross-linking agents, coupling agents, catalysts and the like), is more sensitive to moisture, and can be thickened and aged due to contact with air or hydroxyl groups, moisture residues and the like of the sizing material, so that performance fluctuation and even failure occur; therefore, the actual mixing proportion of the A, B component is different from the design proportion, the performance of the vulcanized silicone rubber does not reach the standard, even the phenomenon of slow vulcanization and partial non-vulcanization occurs, and the further application of the vulcanized silicone rubber is limited to a certain extent.

Therefore, it is necessary to provide an RTV-2 condensation type silicone sealant having high storage stability and low fluctuation in performance.

Disclosure of Invention

Based on the above, the invention aims to provide a two-component condensed type organic silicon sealant and a preparation method thereof, and the two-component condensed type organic silicon sealant has high storage stability and low performance fluctuation.

The specific technical scheme for achieving the aim of the invention comprises the following steps.

In a first aspect of the invention, a two-component condensation type organic silicon sealant is provided, which consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the modified filler is a metal oxide modified by a silane coupling agent, and is prepared by the following method: dispersing metal oxide powder in dimethylbenzene, adding a silane coupling agent under stirring, and heating and refluxing after uniform dispersion; filtering, washing and drying to obtain the product; the base polymer is one or two of hydroxyl-terminated polydimethylsiloxane and alkoxy-terminated polydimethylsiloxane, and the viscosity of the base polymer at 23 ℃ is 1500-80000 mPas.

In a second aspect of the present invention, there is provided a method for preparing a two-component condensed type silicone sealant, comprising the steps of:

(1) Adding the basic polymer, the modified filler, the functional filler and the plasticizer into a kneader according to parts by weight, stirring until the materials are uniform, vacuumizing and defoaming, and discharging to obtain a component A;

(2) Putting the dispersing agent, the filler and the carbon black into a double-star power mixer according to parts by weight, stirring until uniform, and vacuumizing and degassing; mixing and adding the cross-linking agent and the catalyst under the protection of nitrogen, stirring uniformly, vacuumizing and degassing, and discharging to obtain the component B.

The invention has the following beneficial effects:

the double-component condensed type organic silicon sealant disclosed by the invention has the advantages that the silane coupling agent which accelerates hydrolysis and promotes hydrolysis and vulcanization is removed from the component B, and then the metal oxide is subjected to surface modification treatment to obtain the modified filler which is added into the component A.

Detailed Description

The present invention will be described more fully hereinafter in order to facilitate an understanding of the present invention. This invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The experimental methods, in which specific conditions are not noted in the following examples, are generally conducted under conventional conditions or under conditions recommended by the manufacturer. The various chemicals commonly used in the examples are commercially available.

In order to overcome the defects and shortcomings of the prior art, the problems of uneven mixing, unbalanced mixing proportion and unbalanced design proportion of sizing materials are avoided, and the silane coupling agent which accelerates hydrolysis and promotes hydrolytic vulcanization is removed from the component B, so that the sensitivity of the component B with easy hydrolytic activity to air moisture is reduced, the storage stability of the component B is improved, the degradation speed of the curing performance is reduced, meanwhile, the silane coupling agent is subjected to surface modification treatment on metal oxide to obtain modified filler, and the modified filler is added into the component A, so that the compatibility of the metal oxide filler and polysiloxane is improved, and meanwhile, the effects of the silane coupling agent on promoting vulcanization and improving adhesion are maintained. In addition, the type and the addition amount of the silane coupling agent in the modification process can be adjusted to change the surface modification effect of the metal oxide, and the addition amount of the modified filler can be adjusted, so that the construction time of the double-component organosilicon sealant can be simply adjusted from minutes to hours, and the curing speed and the construction time of the sealant can be flexibly adjusted. In addition, the modified filler provided by the invention has the advantages that the conditions are easy to obtain, such as aluminum oxide, ferric oxide, magnesium oxide, zinc oxide and the like, the viscosity of the prepared double-component sealant is lower, the extrusion performance is high, the vulcanization speed is high, the design is controllable, and the double-component sealant is more suitable for an automatic gluing process; the adhesive has the advantages of simple preparation, strong reproducibility, excellent mechanical property, weather resistance, aging resistance, temperature resistance and the like after solidification, and can be widely applied to sealing, bonding and protection in the fields of automobiles, electronic appliances, new energy sources, photovoltaics and the like.

In some embodiments of the invention, a two-component condensation type organic silicon sealant is disclosed, which is composed of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the modified filler is a metal oxide modified by a silane coupling agent, and is prepared by the following method: dispersing metal oxide powder in dimethylbenzene, adding a silane coupling agent under stirring, and heating and refluxing after uniform dispersion; filtering, washing and drying to obtain the product;

the base polymer is one or two of hydroxyl-terminated polydimethylsiloxane and alkoxy-terminated polydimethylsiloxane, and the viscosity of the base polymer at 23 ℃ is 1500-80000 mP.s;

the functional filler in the component A is one or more of nano active calcium carbonate, light calcium carbonate, heavy calcium carbonate, fumed silica and silica micropowder;

the filler in the component B is one or more of heavy calcium carbonate, mica powder, magnesium carbonate and barium sulfate.

In some embodiments, the component a is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

in some embodiments, the component a is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

in some of these embodiments, the silane coupling agent is one or more of 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, N- (N-butyl) -3-aminopropyl trimethoxysilane, N-cyclohexyl-gamma-aminopropyl methyldimethoxysilane, gamma-diethylenetriamine propyl methyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyl trimethoxysilane, N- (. Beta. -aminoethyl) -gamma-aminopropyl triethoxysilane, N-diethyl-3-aminopropyl trimethoxysilane, 3- (phenylamino) propyltrimethoxysilane, 3-piperazinylpropyl methyldimethoxysilane, bis (3-trimethoxysilylpropyl) amine, aminosilane oligomers, cyanopropyl triethoxysilane, 3- (2, 3-epoxypropoxy) propyl trimethoxysilane, beta- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl triethoxysilane, gamma-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyldimethoxysilane, 3-ureidopropyl triethoxysilane, dodecyl triethoxysilane, N-octyl triethoxysilane.

In some embodiments, the metal oxide is one or more of aluminum oxide, ferric oxide, magnesium oxide, zinc oxide, titanium dioxide, zirconium dioxide, and cerium dioxide.

In some embodiments, the weight ratio of metal oxide to silane coupling agent is 100:0.1 to 9.

In some embodiments, the temperature of the heating reflux is 25-90 ℃, and the time of the heating reflux is 0.5-4 h.

In some embodiments, the plasticizer is one or more of dimethyl silicone oil, methoxy silicone oil and hydroxyl silicone oil, and the viscosity of the plasticizer at 23 ℃ is 10-20000 mPas.

In some embodiments, the dispersant is one or both of simethicone, terminal alkoxy dimethicone; the viscosity of the dispersant at 23 ℃ is 100-50000 mPas.

In some embodiments, the cross-linking agent is one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, 1, 2-bis (triethoxysilyl) ethane, 1, 2-bis (trimethoxysilyl) ethane, methyl silicate oligomer, ethyl silicate oligomer.

In some embodiments, the catalyst is one or more of dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin dioctanoate, dimethyl tin dineodecanoate, monobutyl triisooctoate, and chelate tin.

In other embodiments of the present invention, a method for preparing the two-component condensation type silicone sealant is disclosed, comprising the steps of:

(1) Adding the basic polymer, the modified filler, the functional filler and the plasticizer into a kneader according to parts by weight, stirring until the materials are uniform, vacuumizing and defoaming, and discharging to obtain a component A;

(2) Putting the dispersing agent, the filler and the carbon black into a double-star power mixer according to parts by weight, stirring until uniform, and vacuumizing and degassing; mixing and adding the cross-linking agent and the catalyst under the protection of nitrogen, stirring uniformly, vacuumizing and degassing, and discharging to obtain the component B.

In the following examples, the raw materials used were as follows:

hydroxyl-terminated polydimethylsiloxane with viscosity of 1500, 5000, 20000 and 80000 mPs at 23 ℃ respectively purchased from silicon industry;

simethicone, available from the Hesheng silicon industry, has a viscosity at 23℃of 100, 350, 1000 mPas, respectively;

hydroxyl silicone oil with the hydroxyl content of 9-10 percent is purchased from Zhejiang solvent new materials;

methoxy silicone oil with viscosity of 100 mPas at 23 ℃ and purchased from new silicon-based materials;

terminal alkoxy polydimethylsiloxane with viscosity of 1500, 5000, 20000 and 80000 mP.s at 23 ℃ respectively, purchased from Kongkoku Xin;

nano active calcium carbonate, light calcium carbonate and heavy calcium carbonate are purchased from Guangxi Huana;

white carbon black by gas phase method, brand: LM150, R974, purchased from qiangchang desintegration;

silicon micropowder HY-GA-2 and mica powder HY-M1 are purchased from sea euphorbia powder;

magnesium carbonate, available from the company cymbidium kangaroo crown threo practice;

aluminum oxide ZT-L30G, ferric oxide ZT-E01, titanium dioxide ZT05 and magnesium oxide ZT-MH01, which are purchased from the new intelligent titanium nano material;

methyl orthosilicate, ethyl orthosilicate oligomer, dimethyl dimethoxy silane, vinyl trimethoxy silane, 1, 2-bis (triethoxy silicon) ethane, 3-aminopropyl triethoxy silane, gamma-diethylenetriamine propyl methyl dimethoxy silane, N- (2-aminoethyl) -3-aminopropyl methyl dimethoxy silane, cyanopropyl triethoxy silane, N-cyclohexyl-3-aminopropyl methyl dimethoxy silane, 3-methacryloxypropyl methyl dimethoxy silane, N-diethyl-3-aminopropyl trimethoxy silane, N-octyl triethoxy silane, 3-glycidoxy propyl triethoxy silane are purchased from Hubei river as new materials.

The present invention will be described in detail with reference to specific examples.

Example 1

This example first prepared a modified alumina filler comprising the steps of:

dispersing 100 parts of nano aluminum oxide in 100 parts of toluene, adding 3 parts of 3-aminopropyl triethoxysilane and 1 part of gamma-diethylenetriamine propyl methyl dimethoxy silane, heating to 70 ℃ under stirring, refluxing for 2 hours, filtering, drying and crushing to obtain the modified aluminum oxide filler.

The embodiment also provides a two-component condensed type organic silicon sealant, which consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the preparation method of the two-component condensed type organic silicon sealant comprises the following steps:

1. preparation of component A

60 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 80000 mPs at 23 ℃, 40 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 20000 mPs at 23 ℃, 40 parts of modified alumina filler and 80 parts of nano active calcium carbonate are added into a kneader, stirred uniformly, vacuum kneaded for 2 hours, cooled and discharged to obtain a component A;

2. preparation of component B

100 parts of simethicone with the viscosity of 350 mPs at 23 ℃ are put into a double-star power mixer, 50 parts of carbon black is added, and after the simethicone is uniformly dispersed, the mixture is vacuumized and stirred for 2 hours; under the protection of nitrogen, 35 parts of tetraethoxysilane, 10 parts of vinyl trimethoxysilane and 1.2 parts of dibutyltin dilaurate are mixed and added, and the mixture is stirred for 15min and then vacuumized and degassed for 30min; and discharging and sealing to obtain the component B.

When in use, the component A and the component B are mixed according to the mass ratio of 11:1, uniformly mixing, removing bubbles, and completing solidification under the room temperature condition.

Example 2

This example first prepared a modified magnesium oxide filler comprising the steps of:

dispersing 100 parts of superfine magnesium oxide in 100 parts of toluene, adding 5 parts of N- (2-aminoethyl) -3-aminopropyl methyl dimethoxy silane and 1 part of cyanopropyl triethoxy silane, heating to 50 ℃ under stirring, refluxing for 1h, filtering, drying and crushing to obtain the modified magnesium oxide filler.

The embodiment also provides a two-component condensed type organic silicon sealant, which consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the preparation method of the two-component condensed type organic silicon sealant comprises the following steps:

1. preparation of component A

Adding 80 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 20000 mP.s at 23 ℃, 20 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 1500 mP.s at 23 ℃, 20 parts of modified magnesium oxide filler, 70 parts of nano active calcium carbonate, 5 parts of fumed silica and 5 parts of hydroxyl silicone oil with the viscosity of 100 mP.s at 23 ℃ into a kneader, uniformly dispersing, then carrying out vacuum kneading for 2.5min, cooling, and discharging to obtain a component A;

2. preparation of component B

100 parts of simethicone with the viscosity of 100 mPs at 23 ℃ are put into a double-star power mixer, 70 parts of carbon black is added, and after uniform dispersion, the mixture is vacuumized and stirred for 2 hours; under the protection of nitrogen, 35 parts of ethyl orthosilicate oligomer, 10 parts of dimethyl dimethoxy silane and 0.6 part of chelated tin are mixed and added, and the mixture is stirred for 15min and then is vacuumized and degassed for 30min; and discharging and sealing to obtain the component B.

When in use, the component A and the component B are mixed according to the mass ratio of 10:1, uniformly mixing, removing bubbles, and completing solidification under the room temperature condition.

Example 3

This example first prepared a modified ferric oxide filler comprising the steps of:

dispersing 100 parts of nano ferric oxide in 100 parts of toluene, adding 2.5 parts of N-cyclohexyl-3-aminopropyl methyl dimethoxy silane and 1.5 parts of 3-methacryloxypropyl methyl dimethoxy silane, heating to 60 ℃ under stirring, refluxing for 3 hours, filtering, drying and crushing to obtain the modified ferric oxide filler.

The embodiment also provides a two-component condensed type organic silicon sealant, which consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the preparation method of the two-component condensed type organic silicon sealant comprises the following steps:

1. preparation of component A

100 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 5000 mP.s at 23 ℃, 40 parts of modified ferric oxide, 70 parts of silicon micropowder, 6 parts of fumed silica and 4 parts of hydroxyl silicone oil are added into a kneader, dispersed uniformly, vacuum kneaded for 120min, cooled and discharged to obtain a component A;

2. preparation of component B

100 parts of alkoxy polydimethylsiloxane with the viscosity of 5000 mP.s at the temperature of 23 ℃ is put into a double-star dynamic mixer, 60 parts of carbon black and 30 parts of magnesium carbonate are added, and after uniform dispersion, the mixture is vacuumized and stirred for 2 hours; under the protection of nitrogen, 25 parts of 1, 2-bis (triethoxysilyl) ethane, 5 parts of tetraethoxysilane and 0.8 part of dimethyltin di-neodecanoate are mixed and added, and the mixture is stirred for 15min and then vacuumized and deaerated for 30min; and discharging and sealing to obtain the component B.

When in use, the component A and the component B are mixed according to the mass ratio of 5:1, uniformly mixing, removing bubbles, and completing solidification under the room temperature condition.

Example 4

This example first prepared a modified titanium dioxide filler comprising the steps of:

dispersing 100 parts of nano titanium dioxide in 100 parts of toluene, adding 2 parts of N, N-diethyl-3-aminopropyl trimethoxy silane, 0.8 part of N-octyl triethoxy silane and 0.8 part of 3-glycidol ether oxypropyl triethoxy silane, heating to 60 ℃ under stirring, refluxing for 3 hours, filtering, drying and crushing to obtain the modified titanium dioxide filler.

The embodiment also provides a two-component condensed type organic silicon sealant, which consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the preparation method of the two-component condensed type organic silicon sealant comprises the following steps:

1. preparation of component A

60 parts of terminal alkoxy polydimethylsiloxane with the viscosity of 20000 mPs at 23 ℃, 40 parts of terminal alkoxy polydimethylsiloxane with the viscosity of 1500 mPs at 23 ℃, 80 parts of modified titanium dioxide, 10 parts of fumed silica and 10 parts of simethicone with the viscosity of 350 mPs at 23 are added into a kneader, uniformly dispersed, vacuum kneaded for 2.5min, cooled and discharged to obtain a component A;

2. preparation of component B

100 parts of terminal alkoxy polydimethylsiloxane with the viscosity of 20000 mP.s at 23 ℃ are put into a double-star power mixer, 50 parts of carbon black and 50 parts of mica powder are added, and after uniform dispersion, the mixture is vacuumized and stirred for 2 hours; under the protection of nitrogen, 15 parts of methyl orthosilicate, 25 parts of dimethyl dimethoxy silane and 0.8 part of dibutyl tin diacetate are mixed and added, and the mixture is stirred for 15min and then vacuumized and degassed for 30min; and discharging and sealing to obtain the component B.

When in use, the component A and the component B are mixed according to the mass ratio of 4:1, uniformly mixing, removing bubbles, and completing solidification under the room temperature condition.

Comparative example 1

The double-component condensed type organic silicon sealant of the comparative example consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the preparation method of the two-component condensed type organic silicon sealant of the comparative example comprises the following steps:

1. preparation of component A

Adding 60 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 80000 mPs at 23 ℃, 40 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 20000 mPs at 23 ℃, 20 parts of alumina filler, 80 parts of nano active calcium carbonate and 5 parts of hydroxyl silicone oil with the viscosity of 350 mPs at 23 into a kneader, stirring uniformly, then carrying out vacuum kneading for 2 hours, cooling and discharging to obtain a component A;

2. preparation of component B

100 parts of simethicone with the viscosity of 350 mPs at 23 ℃ are put into a double-star power mixer, 50 parts of carbon black is added, and after the simethicone is uniformly dispersed, the mixture is vacuumized and stirred for 2 hours; under the protection of nitrogen, 35 parts of tetraethoxysilane, 10 parts of vinyl trimethoxysilane, 1 part of 3-aminopropyl triethoxysilane, 0.5 part of gamma-diethylenetriamine propyl methyl dimethoxy silane and 1.2 parts of dibutyltin dilaurate are mixed and added, stirred for 15min, and then vacuumized and degassed for 30min; and discharging and sealing to obtain the component B.

When in use, the component A and the component B are mixed according to the mass ratio of 11:1, uniformly mixing, removing bubbles, and completing solidification under the room temperature condition.

Comparative example 2

The double-component condensed type organic silicon sealant of the comparative example consists of an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the preparation method of the two-component condensed type organic silicon sealant of the comparative example comprises the following steps:

1. preparation of component A

Adding 60 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 80000 mPs at 23 ℃, 40 parts of hydroxyl-terminated polydimethylsiloxane with the viscosity of 20000 mPs at 23 ℃, 20 parts of alumina filler, 80 parts of nano active calcium carbonate, 1 part of 3-aminopropyl triethoxysilane, 0.5 part of gamma-diethylenetriamine propyl methyl dimethoxy silane and 5 parts of hydroxyl silicone oil with the viscosity of 350 mPs at 23 ℃ into a kneader, stirring uniformly, then carrying out vacuum kneading for 2 hours, cooling and discharging to obtain a component A;

2. preparation of component B

100 parts of simethicone with the viscosity of 350 mPs at 23 ℃ are put into a double-star power mixer, 50 parts of carbon black is added, and after the simethicone is uniformly dispersed, the mixture is vacuumized and stirred for 2 hours; under the protection of nitrogen, 35 parts of tetraethoxysilane, 10 parts of vinyl trimethoxysilane and 1.2 parts of dibutyltin dilaurate are mixed and added, and the mixture is stirred for 15min and then vacuumized and degassed for 30min; and discharging and sealing to obtain the component B.

When in use, the component A and the component B are mixed according to the mass ratio of 11:1, uniformly mixing, removing bubbles, and completing solidification under the room temperature condition.

Performance testing

Sample preparation and maintenance: adopting the same process conditions, respectively placing A, B components in the embodiment and the comparative example into a vacuum high-speed mixer according to the design proportion for mixing, discharging and tubing for testing; the break time was determined according to GB 16776-2005 annex D.5; measuring the surface dry time according to the GB/T13477.5-2002B method; the extrudability was determined according to BY 3-TMS-006; the initial cure strength was measured according to GB/T528-2009 after 4 hours of curing at room temperature. The A, B component was subjected to accelerated aging at 70℃for 5 days, and the change in the stretch-break time, the tack-free time and the extrudability after aging was measured. The results are shown in Table 1.

TABLE 1

As can be seen from table 1, the two-component condensation type silicone sealants of examples 1 to 4 of the present invention first removed the high-activity silane coupling agent having the effect of promoting hydrolytic vulcanization from the B component, thereby improving the feasibility of the storage stability of the B component; secondly, the surface of the metal oxide is modified by a silane coupling agent to obtain modified filler, and the modified filler is introduced into the component A, so that on one hand, the compatibility of the metal oxide and the polysiloxane organic chain segment is improved, and the dispersibility of the metal oxide is improved; on the other hand, the effect of the silane coupling agent on promoting vulcanization and improving adhesion is maintained, and meanwhile, the problem of self-crosslinking and failure caused by directly adding the silane coupling agent into the component A is avoided. The two-component condensation type silicone sealants of examples 1 to 4 had a change rate of <30% in the time to break before and after aging and in the tack-free property, and a high retention of extrudability. From the performance results of examples 1 to 4, it is understood that the time for pulling the sealant off can be adjusted from 8 minutes to 25 minutes or even 70 minutes by adjusting the amount of the silane coupling agent and the amount of the modified filler when the modified filler is prepared, and the curing speed of the sealant can be adjusted more flexibly.

The double-component condensed type organic silicon sealant of the comparative example 1 is prepared by directly adding a silane coupling agent with the function of promoting hydrolytic vulcanization into a component B, and has better workability, curing property and initial strength before aging; however, after the sealant of comparative example 1 is heated and aged for 5 days at 70 ℃, the component B is hydrolyzed, the activity is reduced and even partially fails, so that the stretch-off time and the surface drying time are obviously slowed down, the actual technological parameters are unbalanced, and the application is seriously influenced.

The two-component condensed type organic silicon sealant of the comparative example 2 is prepared by directly adding a silane coupling agent with the function of promoting hydrolytic vulcanization into the component A, and has excellent workability, curing performance and initial strength performance before aging; however, after the sealant of the comparative example 2 is heated and aged for 5 days at 70 ℃, the A component is self-crosslinked and solidified, so that the product is invalid and cannot be used; the silane coupling agent has high activity and is easy to hydrolyze, promotes the self silicon-oxygen bond to react with the water in the component A to generate silanol with higher activity, and leads to self-curing and losing usability. In comparative example 2, the B component after the silane coupling agent was removed was mixed with the newly formulated a component, and the change in vulcanization time was small, and it was also verified that the storage stability could be effectively improved by removing the silane coupling agent from the B component.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (10)

1. The double-component condensed type organic silicon sealant is characterized by comprising an A component and a B component, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

the modified filler is a metal oxide modified by a silane coupling agent, and is prepared by the following method: dispersing metal oxide powder in dimethylbenzene, adding a silane coupling agent under stirring, and heating and refluxing after uniform dispersion; filtering, washing and drying to obtain the product;

the base polymer is one or two of hydroxyl-terminated polydimethylsiloxane and alkoxy-terminated polydimethylsiloxane, and the viscosity of the base polymer at 23 ℃ is 1500-80000 mPas.

2. The two-component condensed type organic silicon sealant according to claim 1, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

3. the two-component condensed type organic silicon sealant according to claim 2, wherein the A component is prepared from the following raw materials in parts by weight:

the component B is prepared from the following raw materials in parts by weight:

4. a two-component condensation type silicone sealant according to any one of claims 1 to 3, wherein the silane coupling agent is one of 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, N- (N-butyl) -3-aminopropyl trimethoxysilane, N-cyclohexyl- γ -aminopropyl methyldimethoxysilane, γ -diethylenetriamine propyl methyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyl trimethoxysilane, N- (β -aminoethyl) - γ -aminopropyl triethoxysilane, N-diethyl-3-aminopropyl trimethoxysilane, 3- (phenylamino) propyl trimethoxysilane, 3-piperazinylpropyl methyldimethoxysilane, bis (3-trimethoxysilylpropyl) amine, aminosilane oligomers, cyanopropyl triethoxysilane, 3- (2, 3-glycidoxy) propyl trimethoxysilane, β - (3, 4-epoxycyclohexyl) ethyl trimethoxysilane, 3-glycidoxy propyl triethoxysilane, γ -methacryloxypropyl trimethoxysilane, 3-methylpropyloxy-propyl dimethoxy silane, 3-diethoxy-dodecyl silane, N-triethoxy silane, or N-octyl triethoxy silane.

5. A two-component condensation type silicone sealant according to any one of claims 1 to 3, wherein the metal oxide is one or more of aluminum oxide, iron oxide, magnesium oxide, zinc oxide, titanium oxide, zirconium dioxide, and cerium oxide.

6. A two-component condensation type silicone sealant according to any one of claims 1 to 3, wherein the weight ratio of the metal oxide and the silane coupling agent is 100:0.1 to 9.

7. A two-component condensed type silicone sealant according to any one of claims 1 to 3, wherein the temperature of the heat reflow is 25 to 90 ℃, and the time of the heat reflow is 0.5 to 4 hours.

8. The two-component condensed type organic silicon sealant according to any one of claims 1 to 3, wherein the functional filler in the component A is one or more of nano active calcium carbonate, light calcium carbonate, heavy calcium carbonate, fumed silica and silica micropowder; and/or the filler in the component B is one or more of heavy calcium carbonate, mica powder, magnesium carbonate and barium sulfate.

9. A two-component condensation type silicone sealant according to any one of claims 1 to 3, wherein the plasticizer is one or more of simethicone, methoxy silicone oil, and hydroxy silicone oil, preferably, the plasticizer has a viscosity of 10 to 20000mP s at 23 ℃; and/or the number of the groups of groups,

the dispersing agent is one or two of simethicone and terminal alkoxy polydimethyl siloxane, and preferably, the viscosity of the dispersing agent at 23 ℃ is 100-50000 mP.s; and/or the number of the groups of groups,

the cross-linking agent is one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, 1, 2-bis (triethoxysilyl) ethane, 1, 2-bis (trimethoxysilyl) ethane, methyl silicate oligomer and ethyl silicate oligomer; and/or the number of the groups of groups,

the catalyst is one or more of dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin dioctanoate, dimethyl tin dineodecanoate, monobutyl triisooctoate and chelate tin.

10. The method for preparing the two-component condensed type organic silicon sealant according to any one of claims 1 to 9, which is characterized by comprising the following steps:

(1) Adding the basic polymer, the modified filler, the functional filler and the plasticizer into a kneader according to parts by weight, stirring until the materials are uniform, vacuumizing and defoaming, and discharging to obtain a component A;

(2) Putting the dispersing agent, the filler and the carbon black into a double-star power mixer according to parts by weight, stirring until uniform, and vacuumizing and degassing; mixing and adding the cross-linking agent and the catalyst under the protection of nitrogen, stirring uniformly, vacuumizing and degassing, and discharging to obtain the component B.