An isoproportion two-component alcohol-free silicone sealant, its preparation method and application

Abstract

The present invention discloses an isopropionate two-component alcohol-free silicone sealant, its preparation method and application. The sealant comprises component A composed of polydiorganosiloxane with hydroxyl groups at both ends of the molecule, filler and catalyst, and component B composed of polydiorganosiloxane with hydroxyl groups at both ends of the molecule, filler, alcohol-free crosslinking agent, ɑ-aminomethylsilane crosslinking agent and tackifier. The present invention uses a composite catalyst of organic bismuth and organic zinc, which is more environmentally friendly, and the composite catalyst has a faster initial gel rate and an overall curing rate in the later stage; both component A and component B adopt polydiorganosiloxane with hydroxyl groups at both ends of the molecule, significantly reducing the cost of the sealant and facilitating the wide application of the isopropionate two-component alcohol-free sealant in the market; the mixing ratio of component A and component B is 1:1, with low requirements for the metering accuracy of equipment, convenient operation, ensuring the stable performance of the silicone sealant after mixing, and being suitable for continuous production in modern industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of sealants, and particularly relates to an equi-proportion two-component alcohol-free silicone sealant, its preparation method and application. Background Art

[0002] Silicone sealants have excellent weather resistance, high and low temperature resistance, good hydrophobicity, aging resistance and excellent electrical insulation performance, and are widely used in the fields of construction, national defense, household appliances, automobiles, new energy, etc. With the increasing emphasis on production efficiency and product quality stability in society, users' performance requirements for silicone sealants are also continuously improving.

[0003] One-component condensation silicone rubber is widely used in various industrial fields due to its convenient use. However, since its curing speed is restricted by both temperature and humidity, it cannot be cured deeply and it takes several days to be completely cured, which cannot meet the high-efficiency requirements of automated production lines. Condensation two-component room temperature vulcanized (RTV-2) silicone sealants can be cured both internally and externally, and only 1-2 hours are required to meet the basic curing, which is more suitable for bonding and sealing in the automated production industry. Currently, commercially available two-component condensation silicone sealants have the A component composed of α, ω-dihydroxypolydimethylsiloxane mixed with a filler containing a certain amount of moisture, and the B component mainly composed of a plasticizer, a crosslinking agent, a catalyst and a color paste, etc. The mixing ratio of the A and B components is between 4:1 and 20:1. When in use, it has a high requirement for the metering accuracy of the mixing equipment, and when the mixing ratio fluctuates, it will also cause the performance of the silicone sealant to be unstable, and even cause non-curing phenomenon, thus limiting its application in some fields.

[0004] To avoid the phenomenon of uneven mixing of rubber compounds, researchers began to focus on the study of room-temperature vulcanizing silicone rubber in equal proportions. Its silica gel has the advantage of being easily and evenly mixed, avoiding the situation of inconsistent silicone rubber properties. At the same time, it has low requirements for the metering accuracy of production mixing equipment. Compared with conventional two-component condensation sealants, it can better meet the requirements of high efficiency in automated production and stable product quality. Chinese Patent CN102703022 discloses a preparation method of an equal-proportion two-component condensation-type silicone sealant. One component uses α,ω-dihydroxypolydimethylsiloxane as the base polymer, and the other component uses poly(dimethylsiloxane) endblocked with polyalkoxysilyl and α,ω-dihydroxypolydimethylsiloxane as the base polymer, and the catalyst uses organotin or organotitanium. Chinese Patent CN111500251 discloses a preparation method of a two-component condensation-type adhesive sealant. The A and B components of this sealant can be freely combined from 0.5:1 to 5:1, and equal-proportion mixing is also included. One component uses α,ω-dihydroxypolydimethylsiloxane as the base polymer, and the other component uses poly(dimethylsiloxane) endblocked with polyalkoxysilyl as the base polymer, and the catalyst uses organotin. CN1222576 is the same as CN111500251, with the base polymers being α,ω-dihydroxypolydiorganosiloxane and poly(diorganosiloxane) endblocked with polyalkoxysilyl, and the catalyst using organotin.

[0005] The preparation of polyalkoxysilyl-terminated polydiorganosiloxane currently uses the condensation and removal of alcohol by α,ω-dihydroxypolydiorganosiloxane and polyalkoxysilane, or the hydrosilylation of polydiorganosiloxane with unsaturated bonds at the end groups and hydrogen-containing alkoxysilane. Compared with α,ω-dihydroxypolydiorganosiloxane, the synthesis process is complex, the product cost increases, and the market price is relatively high, resulting in an increase in the cost of equal-proportion two-component condensation sealants compared with conventional two-component products. Currently, both commercially available unequal-proportion two-component condensation silicone rubber and the equal-proportion condensation silicone rubber reported in the above literature generally use organotin catalysts. Titanium complexes are likely to cause the product to turn yellow, and the hydrogen bond interaction between titanium and hydroxyl groups when the titanium catalyst is mixed with α,ω-dihydroxypolydiorganosiloxane will cause a sharp increase in viscosity, bringing great difficulties to production. Therefore, titanium is generally not used as a catalyst in two-component condensation sealants. Organotin compounds are highly toxic. According to the EU Directive 2009 / 425 / EC, since July 1, 2010, the EU has restricted the use of organotin in all consumer products to less than 0.1%; since January 1, 2012, mixtures or articles supplied to the public shall not contain dibutyltin with a tin content exceeding 0.1%, and one-component and two-component RTV sealants and adhesives have also been restricted since January 1, 2015. In addition, the use of organotin compounds is clearly prohibited in silicone rubber for food contact.

[0006] At present, the condensation sealants in Wuxi on the market are mainly single-component alcohol-free type and acetone-free type. There is no report on the two-component equal-proportion alcohol-free sealant containing Wuxi titanium in China. Since the alcohol-free room temperature vulcanized rubber has a slight odor and no corrosion to metal materials, it is increasingly widely used in the electronics, new energy, and automotive industries. Therefore, it is of great practical significance to develop an environmentally friendly two-component sealant with low development cost and no tin catalyst. Summary of the Invention

[0007] The primary object of the present invention is to overcome the deficiencies of the prior art and provide an equal-proportion two-component alcohol-free silicone sealant.

[0008] Another object of the present invention is to provide a preparation method of the above-mentioned equal-proportion two-component alcohol-free silicone sealant.

[0009] Still another object of the present invention is to provide the application of the above-mentioned equal-proportion two-component alcohol-free silicone sealant.

[0010] The object of the present invention is achieved by the following technical solutions: An equal-proportion two-component alcohol-free silicone sealant, comprising component A and component B; wherein:

[0011] Component A comprises the following components in parts by mass: 100 parts of polydiorganosiloxane with hydroxyl groups at both ends of the molecule, 10-400 parts of filler, and 0.2-1.6 parts of catalyst.

[0012] Component B comprises the following components in parts by mass: 100 parts of polydiorganosiloxane with hydroxyl groups at both ends of the molecule, 10-500 parts of filler, 3-13 parts of alcohol-free crosslinking agent, 1-4 parts of ɑ-aminomethylsilane crosslinking agent, and 2-7 parts of tackifier.

[0013] In component A:

[0014] The polydiorganosiloxane with hydroxyl groups at both ends of the molecule has the structural formula HO[(R)2SiO] n H; R is -CH3, -C2H5 or phenyl, and its viscosity range at 25°C is 500-100000 mPa·S, and the viscosity is preferably 750-50000 Pa·S. The polydiorganosiloxane with hydroxyl groups at both ends of the molecule can be a mixture of one or more, and the polydiorganosiloxane is preferably α,ω-dihydroxypolydimethylsiloxane.

[0015] The filler is preferably at least one of nano active calcium carbonate, light calcium carbonate, heavy calcium carbonate, fumed silica, precipitated silica, silica powder, diatomite, alumina, aluminum hydroxide, carbon black, and titanium dioxide.

[0016] The dosage of the filler is preferably 50-400 parts.

[0017] The catalyst described above is preferably a catalyst obtained by compounding a bismuth carboxylate and a zinc carboxylate; preferably a catalyst obtained by compounding a bismuth carboxylate and a zinc carboxylate in a mass ratio of 1:1 to 10; more preferably a catalyst obtained by compounding a bismuth carboxylate and a zinc carboxylate in a mass ratio of 1:1 to 4. In the composite catalyst system, the bismuth catalyst provides the gel rate required for curing. If only the bismuth catalyst is used, the later cross-linking and curing rate is slow, and the deep curing performance of the sealant is poor. The zinc catalyst provides a better later cross-linking and curing rate. If only the zinc catalyst is used, the initial gel rate is slow. When the two are used in combination, they have a good catalytic effect, and the sealant has a fast initial gel rate and an overall curing rate in the later stage.

[0018] The bismuth carboxylate described above is preferably at least one of bismuth isooctanoate, bismuth neodecanoate, bismuth laurate, and bismuth naphthenate.

[0019] The zinc carboxylate described above is preferably at least one of zinc isooctanoate and zinc neodecanoate.

[0020] The dosage of the catalyst is preferably 0.3 to 1.0 parts by mass.

[0021] In component B:

[0022] The structural formula of the polydiorganosiloxane with hydroxyl groups at both ends of the molecule is HO[(R)2SiO] n H; R is -CH3, -C2H5 or phenyl, and its viscosity range at 25 °C is 500 - 100000 mPa·S, and the viscosity is preferably 750 - 50000 mPa·S. The polydiorganosiloxane with hydroxyl groups at both ends of the molecule can be a mixture of one or more, and the polydiorganosiloxane is preferably α,ω-dihydroxypolydimethylsiloxane. The structure of the polydiorganosiloxane in component B can be the same as or different from that in component A.

[0023] The filler described above is preferably at least one of nano active calcium carbonate, light calcium carbonate, heavy calcium carbonate, fumed silica, precipitated silica, silica powder, diatomite, alumina, aluminum hydroxide, carbon black, and titanium dioxide.

[0024] The dosage of the filler is preferably 50 to 470 parts; more preferably 56 to 468 parts.

[0025] The de-alcoholic crosslinking agent described above is preferably at least one of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, hydrolyzed oligomer of ethyl silicate, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane, 1,2-bis(methyldimethoxysilyl)ethane, and 1,2-bis(methyldiethoxysilyl)ethane.

[0026] The dosage of the de-alcoholic crosslinking agent described above is preferably 5 to 12 parts by mass.

[0027] The α-aminomethylsilane crosslinking agent described above refers to a silane containing aminomethyl; preferably at least one of anilinomethyltrimethoxysilane, anilinomethyltriethoxysilane, diethylaminomethyltrimethoxysilane, diethylaminomethyltriethoxysilane, and N-(6-aminohexyl)aminomethyltriethoxysilane. Due to its unique structure, the activity of α-aminomethylsiloxane is much greater than that of the γ-silane coupling agent with the same functional groups. It can be used as a crosslinking agent and adhesive for one-component room-temperature vulcanized condensation-type sealants, and has the advantages of fast vulcanization rate and good adhesion performance. The present invention creatively uses α-aminomethylsilane in two-component condensation-type silicone rubber, and when compounded with a Bi / Zn catalyst, it can significantly improve the surface drying speed and overall curing performance of the sealant, and improve the adhesion performance of the silicone rubber, especially suitable for application occasions requiring fast curing and fast adhesion. It is found in the present invention that when the content of the α-aminomethylsilane crosslinking agent is too high, due to its higher crosslinking activity than the de-alcoholic crosslinking agent, it preferentially reacts with hydroxy polysiloxane, resulting in too high a crosslinking density in the early-stage polycondensation reaction of the silicone rubber, which is not conducive to the overflow of small-molecule alcohols generated by the polycondensation reaction from the system, resulting in poor overall curing performance of the colloid. If the content of the α-aminomethylsilane crosslinking agent is too low, it is not conducive to improving the curing rate and adhesion performance of the sealant.

[0028] The dosage of the α-aminomethylsilane crosslinking agent described above is preferably 1 to 3.6 parts by mass.

[0029] The α-aminomethylsilane crosslinking agent described above is equivalent to 5 to 35% of the de-alcoholic crosslinking agent described above; more preferably 15 to 30%.

[0030] The tackifier is preferably at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, isocyanatopropyltriethoxysilane and γ-ureidopropyltrimethoxysilane.

[0031] The dosage of the tackifier is preferably 3 to 6 parts by mass.

[0032] The preparation method of the above-mentioned equal-proportion two-component alcohol-free silicone sealant includes the following steps:

[0033] (1) Preparation of component A:

[0034] ① Use a dynamic mixer to uniformly mix polydiorganosiloxane with hydroxyl groups at both ends and fillers, with a revolution speed of 20 to 40 Hz and a dispersion speed of 20 to 40 Hz, and then control the material temperature not to exceed 70 °C and stir for 1 to 2 hours;

[0035] ② Cool the material finally obtained in step ① to below 40 °C, then add a catalyst, with a revolution rate of 10 to 30 Hz and a dispersion speed of 10 to 30 Hz, stir for 20 to 40 minutes, and use cooling water to control the material temperature not to exceed 40 °C, then evacuate, with a vacuum degree of -0.08 to -0.1 MPa, stir for 30 to 60 minutes, and finally discharge to obtain component A, and store it in a sealed manner;

[0036] (2) Preparation of component B:

[0037] ① Use a dynamic mixer to uniformly mix polydiorganosiloxane with hydroxyl groups at both ends and fillers, with a revolution speed of 20 to 40 Hz and a dispersion speed of 20 to 40 Hz, and at the same time heat the material to 100 to 130 °C, control the vacuum degree to -0.08 to -0.1 MPa, and stir for 1 to 2 hours;

[0038] ②Cool the material finally obtained in step ① to below 40°C, then add a non-alcoholic crosslinking agent, an ɑ-aminomethylsilane crosslinking agent, and a tackifier. The revolution speed is 10 - 30 Hz, the dispersion speed is 10 - 30 Hz, and use cooling water to control the material temperature not to exceed 40°C. At the same time, evacuate to a vacuum degree of -0.08 to -0.1 MPa, stir for 30 - 60 minutes, and finally discharge to obtain the finished product of component B.

[0039] The above-mentioned equal-proportion two-component non-alcoholic silicone sealant can undergo a polycondensation reaction and crosslink into a tin-free silicone elastomer under ambient temperature and in the presence of water. This elastomer cures rapidly, adheres well to various substrates, and can play the roles of adhesion and sealing. It is particularly suitable for occasions where tin use is restricted and can be widely used in the fields of electronics and electrical appliances, construction, new energy, automobiles, aerospace, etc.

[0040] When applying the above-mentioned equal-proportion two-component non-alcoholic silicone sealant, mix component A and component B in a mass ratio of 1:1 and then it can be used.

[0041] The present invention has the following advantages and effects compared with the prior art:

[0042] (1) The present invention uses a non-toxic organic bismuth and organic zinc composite catalyst to replace the toxic organotin compound and the titanium complex that easily causes the product to turn yellow, meeting the environmental protection requirements and can be used as a food-contact type silicone rubber.

[0043] (2) The present invention uses an appropriate amount of α-aminomethyltrialkoxysilane to replace part of the alkoxysilane crosslinking agent, improving the relatively slow catalytic activity of Bi / Zn, increasing the curing rate and adhesion performance of the sealant, and can be applied to occasions requiring rapid curing and rapid adhesion.

[0044] (3) The present invention places the organic bismuth and organic zinc composite catalyst and the crosslinking agent in different components respectively, improving the storage stability of the components, especially the storage performance of the curing agent component. The storage is stable, and the construction performance, adhesion performance, and physical properties show no significant changes after 6 months.

[0045] (4) In the present invention, all the high-molecular polymers participating in the crosslinking of the sealant use α,ω-dihydroxypolydimethylsiloxane, replacing the commonly used hydroxy-terminated polydimethylsiloxane and the mixture of polyalkoxy-terminated polyorganosiloxane in the market, significantly reducing the cost of the sealant and facilitating the wide application of the equal-proportion two-component non-alcoholic sealant in the market.

[0046] (5) In the present invention, the mass or volume mixing ratio of component A and component B is 1:1, which has low requirements for the metering accuracy of the equipment, is easy to operate, ensures the stable performance of the silicone sealant after mixing, is suitable for continuous production in modern industry, and is conducive to wide application in the fields of electronics and electrical appliances, construction, new energy, automobiles, aerospace, etc. Detailed implementation manners

[0047] The present invention will be further described in detail below in conjunction with embodiments, but the implementation manners of the present invention are not limited thereto.

[0048] Embodiment 1

[0049] (1) The preparation of Component A is as follows:

[0050] 1) Add 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s, 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 20000 mPa·s, and 100 parts of active calcium carbonate (commercial model SP100, Shanxi Lanhua Huaming Nano Materials Co., Ltd.) into a dynamic mixer. The revolution speed is 35 Hz, the dispersion speed is 35 Hz, stir for 2 hours, and use cooling circulating water to control the temperature not to exceed 70 °C;

[0051] 2) After the above materials are stirred evenly, add 0.15 parts of bismuth neodecanoate and 0.15 parts of zinc neodecanoate. The revolution rate is 20 Hz, the dispersion speed is 20 Hz, stir for 30 minutes, and use cooling water to control the material temperature not to exceed 40 °C during the stirring and dispersion process. Then evacuate, the vacuum degree is -0.08 to -0.1 MPa, stir for 30 minutes, and finally discharge to obtain the finished product of Component A, and store it in a sealed manner.

[0052] (2) The preparation of Component B is as follows:

[0053] 1) Add 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s, 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 20000 mPa·s, and 116 parts of active calcium carbonate (commercial model SP100, Shanxi Lanhua Huaming Nano Materials Co., Ltd.) into a dynamic mixer. The revolution speed is 35 Hz, the dispersion speed is 35 Hz, and at the same time heat the materials to 100 - 130 °C, control the vacuum degree to -0.08 to -0.1 MPa, and stir for 2 hours;

[0054] 2) Cool the above materials to below 40 °C, add 10 parts of methyltrimethoxysilane, 1.5 parts of diethylaminomethyltriethoxysilane, 3 parts of γ-aminopropyltriethoxysilane, and 2 parts of γ-(2,3-epoxypropoxy)propyltriethoxysilane. The revolution rate is 20 Hz, the dispersion speed is 20 Hz, and use cooling water to control the material temperature not to exceed 40 °C. At the same time, evacuate, the vacuum degree is -0.08 to -0.1 MPa, stir for 40 minutes, and finally discharge to obtain the finished product of Component B, and store it in a sealed manner.

[0055] (3) Mix the manufactured Component A and Component B in a mass ratio of 1:1, and the performance details of the product are shown in Table 1 and Table 2.

[0056] The said parts are all by mass, and the same applies to the following examples.

[0057] Example 2

[0058] (1) The preparation of component A is as follows:

[0059] 1) Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s and 50 parts of silica powder into a dynamic mixer. The revolution speed is 30 Hz, the dispersion speed is 30 Hz, stir for 2 hours, and use cooling circulating water to control the temperature not to exceed 70 °C;

[0060] 2) After the above materials are stirred evenly, add 0.2 part of bismuth isooctanoate and 0.4 part of zinc isooctanoate. The revolution rate is 20 Hz, the dispersion speed is 20 Hz, stir for 30 minutes, and use cooling water to control the material temperature not to exceed 40 °C during the stirring and dispersion process. Then evacuate, with a vacuum degree of -0.08 to -0.1 MPa, stir for 30 minutes, and finally discharge to obtain the finished product of component A, and store it in a sealed manner.

[0061] (2) The preparation of component B is as follows:

[0062] 1) Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s and 54 parts of silica powder into a dynamic mixer. The revolution speed is 30 Hz, the dispersion speed is 30 Hz, and at the same time heat the material to 100 - 130 °C, control the vacuum degree to -0.08 to -0.1 MPa, and stir for 2 hours;

[0063] 2) Cool the above materials to below 40 °C, add 5 parts of tetrapropoxysilane, 1 part of anilinomethyltriethoxysilane, and 3 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. The revolution rate is 20 Hz, the dispersion speed is 20 Hz, and use cooling water to control the material temperature not to exceed 40 °C. At the same time, evacuate, with a vacuum degree of -0.08 to -0.1 MPa, stir for 30 minutes, and finally discharge to obtain the finished product of component B, and store it in a sealed manner.

[0064] (3) Mix the manufactured components A and B in a mass ratio of 1:1. For the performance details of the product, see Table 1 and Table 2.

[0065] Example 3

[0066] (1) The preparation of component A is as follows:

[0067] 1) Add 80 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s and 20 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50000 mPa·s, and 200 parts of aluminum hydroxide into a dynamic mixer. The revolution speed is 35 Hz, the dispersion speed is 35 Hz, stir for 2 hours, and use cooling circulating water to control the temperature not to exceed 70 °C;

[0068] 2) After the above materials are stirred evenly, add 0.2 parts of bismuth laurate and 0.8 parts of zinc octoate, with a revolution rate of 20 Hz, a dispersion speed of 20 Hz, stir for 30 minutes, and control the material temperature not to exceed 40 °C with cooling water during the stirring and dispersion process. Then evacuate to a vacuum degree of -0.08 to -0.1 MPa, stir for 30 minutes, and finally discharge to obtain the finished product of Component A, which is stored in a sealed manner.

[0069] (2) The preparation of Component B is as follows:

[0070] 1) Add 80 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s, 20 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50000 mPa·s, and 221 parts of aluminum hydroxide into a dynamic mixer, with a revolution speed of 30 Hz, a dispersion speed of 30 Hz, heat the materials to 100 - 130 °C at the same time, control the vacuum degree to -0.08 to -0.1 MPa, and stir for 2 hours;

[0071] 2) Cool the above materials to below 40 °C, add 7 parts of 1,2-bis(triethoxysilyl)ethane, 1.8 parts of N-(6-aminohexyl)aminomethyltriethoxysilane, 2 parts of γ-aminopropyltriethoxysilane, 2.5 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, with a revolution rate of 20 Hz, a dispersion speed of 20 Hz, control the material temperature not to exceed 40 °C with cooling water, evacuate to a vacuum degree of -0.08 to -0.1 MPa at the same time, stir for 30 minutes, and finally discharge to obtain the finished product of Component B, which is stored in a sealed manner.

[0072] (3) Mix the manufactured Component A and Component B in a mass ratio of 1:1. The detailed performance of the product is shown in Table 1 and Table 2.

[0073] Example 4

[0074] (1) The preparation of Component A is as follows:

[0075] 1) Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 750 mPa·s and 400 parts of spherical alumina (product model GD-S010Q, Guangdong Gego New Materials Co., Ltd.) into a dynamic mixer, with a revolution speed of 30 Hz, a dispersion speed of 30 Hz, stir for 2 hours, and control the temperature not to exceed 70 °C with cooling circulating water;

[0076] (2) After the above materials are stirred evenly, 0.3 parts of bismuth naphthenate and 0.6 parts of zinc neodecanoate are added. The revolution speed is 20 Hz, the dispersion speed is 20 Hz, and the mixture is stirred for 30 minutes. During the stirring and dispersion process, the material temperature is controlled not to exceed 40 °C with cooling water. Then, vacuum is pumped, the vacuum degree is -0.08 to -0.1 MPa, and the mixture is stirred for 30 minutes. Finally, the finished product of Component A is discharged and stored in a sealed manner.

[0077] (2) The preparation of Component B is as follows:

[0078] (1) Add 100 parts of α,ω-dihydroxy polydimethylsiloxane with a viscosity of 750 mPa·s and 468 parts of spherical alumina (commercial model GD-S010Q, Guangdong Gingo New Materials Co., Ltd.) into a dynamic mixer. The revolution speed is 30 Hz, the dispersion speed is 30 Hz. At the same time, the material is heated to 100 - 130 °C, the vacuum degree is controlled at -0.08 to -0.1 MPa, and the mixture is stirred for 2 hours.

[0079] (2) Cool the above materials to below 40 °C, add 12 parts of tetraethoxysilane, 3.6 parts of diethylaminomethyltrimethoxysilane, 2 parts of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane. The revolution rate is 20 Hz, the dispersion speed is 20 Hz, and the material temperature is controlled not to exceed 40 °C with cooling water. At the same time, vacuum is pumped, the vacuum degree is -0.08 to -0.1 MPa, and the mixture is stirred for 30 minutes. Finally, the finished product of Component B is discharged and stored in a sealed manner.

[0080] (3) Mix the manufactured Components A and B in a mass ratio of 1:1. The detailed performance of the product is shown in Table 1 and Table 2.

[0081] Comparative Example 1

[0082] Compared with Example 1, in Component A, 0.3 parts of bismuth neodecanoate is used to replace 0.15 parts of bismuth neodecanoate and 0.15 parts of zinc neodecanoate, and the other components and the preparation process are the same as those in Example 1. Mix the manufactured Component A and Component B in a mass ratio of 1:1. The detailed performance of the product is shown in Table 1.

[0083] Comparative Example 2

[0084] Compared with Example 1, in Component A, 0.3 parts of zinc neodecanoate is used to replace 0.15 parts of bismuth neodecanoate and 0.15 parts of zinc neodecanoate, and the other components and the preparation process are the same as those in Example 1. Mix the manufactured Component A and Component B in a mass ratio of 1:1. The detailed performance of the product is shown in Table 1.

[0085] Comparative Example 3

[0086] Compared with Example 1, for Component B, 11.5 parts of methyltrimethoxysilane is used to replace 10 parts of methyltrimethoxysilane and 1.5 parts of diethylaminomethyltriethoxysilane in Example 1, and the other components and the preparation process are the same as those in Example 1. The obtained Component A and Component B are mixed at a mass ratio of 1:1, and the performance details of the product are shown in Table 1.

[0087] Comparative Example 4

[0088] Compared with Example 1, for Component B, 6 parts of methyltrimethoxysilane and 5.5 parts of diethylaminomethyltriethoxysilane are used to replace 10 parts of methyltrimethoxysilane and 1.5 parts of diethylaminomethyltriethoxysilane in Example 1, and the other components and the preparation process are the same as those in Example 1. The obtained Component A and Component B are mixed at a mass ratio of 1:1, and the performance details of the product are shown in Table 1.

[0089] Comparative Example 5

[0090] (1) The preparation of Component A is as follows:

[0091] 1)) Add 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s, 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 20000 mPa·s, and 100 parts of active calcium carbonate (commercial model SP100, Shanxi Lanhua Huaming Nano Materials Co., Ltd.). The revolution speed is 35 Hz, the dispersion speed is 35 Hz, stir for 2 hours, and use cooling circulating water to control the temperature not exceeding 70 °C;

[0092] (2) Cool the above materials to below 40 °C, with a revolution rate of 20 Hz and a dispersion speed of 20 Hz, stir for 30 minutes. During the stirring and dispersion process, use cooling water to control the material temperature not exceeding 40 °C. Then evacuate to a vacuum degree of -0.08 to -0.1 MPa, stir for 30 minutes, and finally discharge to obtain the finished product of Component A, which is sealed and stored.

[0093] (2) The preparation of Component B is as follows:

[0094] (1) Add 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 1500 mPa·s, 50 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 20000 mPa·s, and 116 parts of active calcium carbonate (commercial model SP100, Shanxi Lanhua Huaming Nano Materials Co., Ltd.) into a dynamic mixer. The revolution speed is 35 Hz, the dispersion speed is 35 Hz, and at the same time heat the materials to 100 - 130 °C, control the vacuum degree to -0.08 to -0.1 MPa, and stir for 2 hours;

[0095] (2) Cool the above materials to below 40°C, add 11.5 parts of methyltrimethoxysilane, 3 parts of γ-aminopropyltriethoxysilane, 2 parts of γ-(2,3-epoxypropoxy)propyltriethoxysilane, and 0.1 part of dibutyltin diisooctoate. The revolution rate is 20 Hz and the dispersion speed is 20 Hz. Control the material temperature with cooling water not to exceed 40°C. At the same time, evacuate to a vacuum degree of -0.08 to -0.1 MPa and stir for 40 minutes. Finally, discharge to obtain the finished product of Component B and store it in a sealed manner.

[0096] (3) Mix the manufactured Component A and Component B in a mass ratio of 1:1. See Tables 1 and 2 for the details of each property of the product.

[0097] Comparative Example 6

[0098] Compared with Comparative Example 5, 0.1 part of the catalyst dibutyltin diisooctoate is placed in Component A and no catalyst is added to Component B. The other components are the same as those in Comparative Example 5, and the preparation process is the same as that in Example 1. Mix the manufactured Component A and Component B in a mass ratio of 1:1. See Table 1 for the details of each property of the product.

[0099] Performance test method:

[0100] Surface drying test method: GB / T 13477.5.

[0101] Hardness test method: GB / T531.

[0102] Internal hardness test method: Pour a certain amount of the mixed adhesive into a disposable plastic cup, control the thickness to be 1 cm, and test the bottom hardness according to GB / T531.

[0103] Tensile strength and elongation at break: GB / T13477.5.

[0104] Extrudability: Test the extrusion quality under the conditions of an extrusion nozzle diameter of 3.5 mm and 0.3 Mpa×10 s.

[0105] Adhesion test method: Extrude the two-component glue on a clean substrate to form at least a 10 cm glue strip with a glue width of about 15 mm and a glue thickness of about 22 mm. After curing at room temperature of 25±5°C and humidity of 55±5% for 24 h, tear off the glue layer and calculate the remaining area on the substrate.

[0106] Table 1 (Initial performance test of silicone rubber)

[0107]

[0108] Table 2

[0109]

[0110]

[0111] As can be seen from the data in Table 1, the compounding of Bi / Zn catalysts has good catalytic effects. Introducing an appropriate amount of α-aminomethyltrialkoxysilane into the crosslinking agent can improve the curing rate and the bonding effect with the polymer material. Compared with the conventional two-component de-alcoholic sealants with equal proportions on the current market, the raw material cost is reduced. Moreover, since the catalyst and the crosslinking agent are placed in different components respectively, the storage stability of the curing agent component is improved. In Comparative Example 5, the organotin catalyst, the crosslinking agent, the adhesive, and the hydroxyl-terminated dimethylsiloxane are placed in the same component. Even if it is stored in a sealed manner to isolate moisture, due to the catalytic effect of the tin catalyst, the crosslinking agent and the adhesive will inevitably react with the alkoxy-terminated dimethylsiloxane, resulting in a decrease in the extrudability of the product, an extension of the operation time, a deterioration of the deep curing performance, and a decrease in the mechanical properties and bonding properties of the material. In Comparative Example 6, the organotin catalyst is added to Component A and Component B does not contain a catalyst. After being placed for 6 months, the extrudability of Component A decreases significantly and basically loses its extrudability, indicating that the tin catalyst promotes the chain reaction of the hydroxyl-terminated dimethylsiloxane, resulting in a vulcanization phenomenon and making it impossible to extrude. Moreover, in Comparative Example 6, the A / B components are mixed and do not cure, and it has lost its application value.

[0112] The above embodiments of the present invention achieve the following technical effects: The catalyst is non-toxic and environmentally friendly, has a fast curing rate, good deep curing performance, excellent bonding performance, and good storage stability of the two-component glue.

[0113] The above embodiments only represent several implementation manners of the present invention, but should not be construed as limiting the scope of the invention patent. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A proportional two-component alcohol-free silicone sealant, characterized in that: It includes Component A and Component B; among them, Component A is composed of components in the following parts by mass: 100 parts of polydiorganosiloxane with hydroxyl groups at both ends of the molecule, 10 - 400 parts of filler, and 0.2 - 1.6 parts of catalyst; Component B is composed of components in the following parts by mass: 100 parts of polydiorganosiloxane with hydroxyl groups at both ends of the molecule, 10 - 500 parts of filler, 3 - 13 parts of alcohol - releasing cross - linker, 1 - 4 parts of ɑ - aminomethylsilane cross - linker, and 2 - 7 parts of tackifier; The catalyst is a catalyst obtained by compounding bismuth - containing carboxylate and zinc - containing carboxylate; The polydiorganosiloxane with hydroxyl groups at both ends of the molecule has a viscosity range of 500 - 100000 mPa·S at 25°C; The ɑ - aminomethylsilane cross - linker is at least one of phenylaminomethyltrimethoxysilane, phenylaminomethyltriethoxysilane, diethylaminomethyltrimethoxysilane, diethylaminomethyltriethoxysilane, and N - (6 - aminohexyl)aminomethyltriethoxysilane.

2. The equal - proportion two - component alcohol - releasing silicone sealant according to claim 1, wherein: In Component A: The structural formula of the polydiorganosiloxane with hydroxyl groups at both ends of the molecule is HO[(R)2SiO] n H; R is -CH3, -C2H5 or phenyl; The filler is at least one of nano - active calcium carbonate, light calcium carbonate, heavy calcium carbonate, fumed silica, precipitated silica, silica powder, diatomite, alumina, aluminum hydroxide, carbon black, and titanium dioxide; The bismuth - containing carboxylate is at least one of bismuth isooctanoate, bismuth neodecanoate, bismuth laurate, and bismuth naphthenate; The zinc - containing carboxylate is at least one of zinc isooctanoate and zinc neodecanoate; In Component B: The structural formula of the polydiorganosiloxane with hydroxyl groups at both ends of the molecule is HO[(R)2SiO] n H; R is -CH3, -C2H5 or phenyl; The filler is at least one of nano - active calcium carbonate, light calcium carbonate, heavy calcium carbonate, fumed silica, precipitated silica, silica powder, diatomite, alumina, aluminum hydroxide, carbon black, and titanium dioxide; The alcohol - releasing cross - linker is at least one of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, hydrolyzed oligomer of ethyl silicate, 1,2 - bis(trimethoxysilyl)ethane, 1,2 - bis(triethoxysilyl)ethane, 1,2 - bis(methyldimethoxysilyl)ethane, and 1,2 - bis(methyldiethoxysilyl)ethane. The tackifier is at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, isocyanatopropyltriethoxysilane, and γ-ureidopropyltrimethoxysilane.

3. The equal-proportion two-component alcohol-free silicone sealant according to claim 1 or 2, characterized in that: The polydiorganosiloxane with hydroxyl groups at both ends of the molecule is α,ω-dihydroxypolydimethylsiloxane.

4. The equal-proportion two-component alcohol-free silicone sealant according to claim 1 or 2, characterized in that: The mass ratio of the bismuth carboxylate to the zinc carboxylate in the catalyst is 1:1 - 1:

10.

5. The equi-proportion two-component alcohol-free silicone sealant according to claim 4, wherein: The mass ratio of the bismuth carboxylate to the zinc carboxylate in the catalyst is 1:1 - 1:

4.

6. The equal-proportion two-component alcohol-free silicone sealant according to claim 1 or 2, characterized in that: The dosage of the ɑ-aminomethylsilane crosslinking agent is 1 - 3.6 parts by mass.

7. The preparation method of the isoproportion two-component alcohol-eliminating type silicone sealant according to any one of claims 1 to 6, characterized in that It includes the following steps: (1) Preparation of Component A: ① Use a dynamic mixer to uniformly mix the polydiorganosiloxane with hydroxyl groups at both ends of the molecule and the filler, with a revolution speed of 20 - 40 Hz and a dispersion speed of 20 - 40 Hz, and then stir for 1 - 2 hours while controlling the material temperature not to exceed 70°C; ② Cool the material finally obtained in step ① to below 40°C, then add the catalyst, with a revolution rate of 10 - 30 Hz and a dispersion speed of 10 - 30 Hz, stir for 20 - 40 minutes, and use cooling water to control the material temperature not to exceed 40°C, then evacuate, with a vacuum degree of -0.08 - -0.1 MPa, stir for 30 - 60 minutes, and finally discharge to obtain Component A, which is stored in a sealed manner; (2) Preparation of Component B: ① Use a dynamic mixer to uniformly mix the polydiorganosiloxane with hydroxyl groups at both ends of the molecule and the filler, with a revolution speed of 20 - 40 Hz and a dispersion speed of 20 - 40 Hz, and at the same time heat the material to 100 - 130°C, control the vacuum degree to -0.08 - -0.1 MPa, and stir for 1 - 2 hours; ② Cool the material finally obtained in step ① to below 40°C, then add the alcohol-free crosslinking agent, ɑ-aminomethylsilane crosslinking agent, and tackifier, with a revolution rate of 10 - 30 Hz and a dispersion speed of 10 - 30 Hz, and use cooling water to control the material temperature not to exceed 40°C, and at the same time evacuate, with a vacuum degree of -0.08 - -0.1 MPa, stir for 30 - 60 minutes, and finally discharge to obtain the finished product of Component B.

8. Application of the equimolar two-component alcohol-free silicone sealant according to any one of claims 1 - 6 in the fields of electronic appliances, construction, new energy, automobiles, and aerospace.

9. The application according to claim 8, wherein It includes the following steps: The A component and the B component in the equal-proportion two-component alcohol-free silicone sealant described in any one of claims 1 to 6 are mixed evenly at a mass ratio of 1:1 and then can be used.

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