Preparation method of silane modified resin and green environment-friendly sealant

Abstract

The invention relates to the technical field of high polymer materials, in particular to a silane modified resin and a preparation method of a green environment-friendly sealant. According to the preparation method disclosed by the invention, the preparation method of the silane modified resin is constructed by a side group modification method, and the green and environment-friendly silane modified sealant is prepared by adopting an environment-friendly plasticizer and can pass the European Union RoHS detection. The method is scientific, reasonable, rich in raw materials, green, environment-friendly, pollution-free and easy to produce and prepare. The whole preparation process is easy to operate, environmental friendliness is fully reflected, and a solid and powerful technical support is provided for sustainable development of the sealant industry. The preparation method has a good application prospect, is an innovation in preparation methods of silane modified resin and green and environment-friendly sealants, and has remarkable economic and social benefits.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a preparation method of a silane-modified resin and a green environmentally friendly sealant. Background Art

[0002] As a new type of sealing material, silane modified sealant has shown strong momentum in the industry development in recent years. With the continuous development of the construction, automobile, electronics and other industries, the demand for sealing materials continues to increase. With its excellent performance, silane modified sealant has gradually expanded its market share. At present, the global silane modified sealant market shows a stable growth trend and is expected to maintain a high growth rate in the next few years. In China, with the improvement of the country's environmental protection requirements and the continuous improvement of building energy-saving standards, the application scope of silane modified sealants is also constantly expanding, and the market prospects are broad.

[0003] Silane modified sealants release small molecule alcohols during the curing process, without any harmful emissions, which meets modern environmental protection requirements. They have good adhesion to a variety of substrates, including glass, metal, plastic, etc., and can form a firm seal. They can resist the influence of natural factors such as ultraviolet rays, temperature changes, humidity, etc., and maintain stable sealing performance for a long time. The surface of the cured sealant can be painted without affecting the appearance of the building. They can adapt to the displacement changes of various structures and effectively prevent leakage. Based on the many advantages of silane modified sealants, it is of great significance to develop high-performance silane modified sealant technology.

[0004] Silane-modified resin, as the base resin for preparing silane-modified sealants, has a very important influence on the comprehensive performance of the product. At present, the existing technology mainly adopts silane modification at the end group of the polymer in the process of preparing silane-modified resin, and has been successfully applied to many fields. The preparation of silane-modified resin by the side group modification method can effectively increase the content of silicone therein, and greatly improve the weather resistance and mechanical properties of the sealant. At present, there are few studies on silane modification of polymers by side groups. In addition, most of the existing silane-modified sealants contain benzene derivatives, such as ortho-phthalate plasticizers, which have certain hazards to the human body or the environment in some special application fields. Therefore, it is of great significance to develop silane-modified sealants that do not contain benzene derivatives. Summary of the invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, one of the purposes is to provide a method for preparing a silane-modified resin modified by a side group; the second purpose is to provide a method for preparing a green and environmentally friendly silane-modified sealant that does not contain benzene derivatives.

[0006] The technical solution provided by the present invention is a method for preparing a silane-modified resin and a green environmentally friendly sealant, comprising the following steps:

[0007] (1) Add cis-2-butene-1,4-diol and 3-mercaptopropyltrimethoxysilane (KH590) into a reaction kettle, add 2,2'-azobisisobutyronitrile (AIBN) under continuous stirring, and react at 78-85° C. for 3.0-3.5 hours under nitrogen protection to obtain the product 2-((3-(trimethoxysilyl)propyl)thio)butane-1,4-diol (HO-Silane); wherein the molar ratio of cis-2-butene-1,4-diol, KH590, and AIBN is 1:1:0.005-0.001.

[0008] (2) Put the polyol into a four-necked flask equipped with a thermometer, mechanical stirring and vacuum gauge, evacuate to above -0.095 MPa, and heat to 100-110° C., and keep for 1.5-2 hours to remove water in the reactants; under nitrogen protection, cool to 70-80° C., add isocyanate with an R value (ratio of -NCO to -OH groups) of 2.0-3.0, and then add 0.001% to 0.01% by mass of catalyst 1 based on the total mass of the feed, heat to 80-85° C., and react for 2.5-3.0 hours to obtain a prepolymer;

[0009] (3) Add the prepared HO-Silane to the reaction system, and then add 0.01% to 0.01% of the total mass of the feed catalyst 1, react at 80 to 85° C. for 2.5 to 3.0 hours under nitrogen protection, and then reduce the temperature to 25° C. to obtain a silane-modified resin; wherein the amount of HO-Silane is calculated based on the mass of the polyol, and 9 to 18 parts by mass of HO-Silane are added for every 100 parts by mass of the polyol.

[0010] (4) Mix the silane modified resin, environmentally friendly plasticizer and inorganic filler in a double planetary power mixer, and stir at a high speed of less than 80° C. for 10 minutes under nitrogen protection; add coupling agent 1, coupling agent 2, ultraviolet light absorber and light stabilizer to the mixer, and stir at a high speed of less than 80° C. for 10 minutes under nitrogen protection; add catalyst 2 to the mixer, and stir at a high speed of less than 80° C. for 10 minutes under nitrogen protection, vacuum degassing, and packaging to obtain a green environmentally friendly sealant; the total amount is measured according to the following mass parts per 100 mass parts: 15-35 parts of silane modified resin, 15-25 parts of environmentally friendly plasticizer, 35-65 parts of inorganic filler, 0.5-1 part of coupling agent 1, and 0.5-1 part of coupling agent 2; 0-0.5 parts of ultraviolet light absorber, 0-0.5 parts of light stabilizer, and 0.01-1 parts of catalyst 2.

[0011] The polyol is polyoxypropylene diol, polytetramethylene glycol, polypropylene carbonate diol, one or a mixture of the two or more thereof, and the molecular weight thereof is 1000-2000 g / mol.

[0012] The diisocyanate is an isocyanate that does not contain benzene series, including cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, one or a mixture of several.

[0013] Wherein, the catalyst 1 is one of dibutyltin dilaurate and dibutyltin dichloride or a mixture of the two; the catalyst 2 is chelated tin (360).

[0014] Wherein, the coupling agent 1 is KH-171; the coupling agent 2 is KH-560.

[0015] The environmentally friendly plasticizer is a cyclohexane polyacid derivative, including dioctyl cyclohexane 1,2-dicarboxylate (DEHCH), dibutyl cyclohexane 1,2-dicarboxylate (DBCH), diisobutyl cyclohexane 1,2-dicarboxylate (DIBCH), diisononyl cyclohexane 1,2-dicarboxylate (DINCH), di(2-propylheptyl) cyclohexane 1,2-carboxylate (DPHCH), and diisodecyl cyclohexane 1,2-dicarboxylate (DIDCH), one or more of which are used in combination.

[0016] The inorganic filler is nano calcium carbonate, active calcium carbonate, talcum powder, titanium dioxide, gas silica, molecular sieve, one or a combination of them.

[0017] The preparation method of the silane-modified resin of the present invention is a method for modifying the silane-modified resin by a side group, thereby increasing the organic silicon content of the silane-modified sealant and improving the weather resistance, durability, reliability, etc. of the material. A high-strength material can be formed by moisture curing.

[0018] The method for curing a silane-modified resin to form an elastomer of the present invention is as follows: adding catalyst 1 and catalyst 2 to the resin and then dispersing the resin in a vacuum degassing disperser. Spreading the prepared resin on a polytetrafluoroethylene (PTFE) mold plate, and smearing the remaining resin on a substrate with a scraper (the smearing specification is 25 mm×12.5 mm), and then curing the polytetrafluoroethylene mold plate and the substrate at (23±2)°C and (50±5)% relative humidity according to national standards and then testing.

[0019] The hardness of the elastomer formed by moisture curing of the silane-modified resin of the present invention gradually increases with the increase of R value. When the R value is 2.2, the hardness is 37.2A, and when the R value is 3.0, the hardness is 48.0A.

[0020] The silane modified resin of the present invention has a resin viscosity that gradually decreases as the R value increases. When the R value is 2.2, the viscosity is 1890 mPa·s; when the R value is 3.0, the viscosity is 1270 mPa·s.

[0021] The tensile strength and elongation at break of the elastomer formed after the moisture curing of the silane-modified resin of the present invention vary with the change of the R value. As the R value increases, the tensile strength increases from 0.892MPa to 1.381MPa, which indicates that within the low R value range, the introduction of active silane groups helps to increase the number of crosslinking points, thereby increasing the crosslinking density and improving the rigidity and strength of the material. When the R value continues to increase, the tensile strength begins to decrease and eventually decreases to 0.554MPa. At the same time, the elongation at break gradually decreases with the increase of the R value, from 272.61% to 140.07%.

[0022] The relationship between the water contact angle and the R value of the elastomer formed after the moisture curing of the silane-modified resin of the present invention shows the wettability of water to the elastomer. Since the three-dimensional cross-linked network structure of -Si-O-Si- is non-polar and incompatible with the polar molecule H2O, the elastomer exhibits good hydrophobicity and produces a contact angle greater than 90°. As the R value increases, the static water contact angle gradually increases from 92.2° to 118.2°. This is because the larger the R value, the more active silane groups are introduced, and the more -Si-O-Si- structures are formed. During the curing process, a large amount of -Si-O-Si- three-dimensional cross-linked network structures gradually migrate to the polymer surface, reducing the surface energy of the elastomer, making its surface less likely to be wetted by water, thereby increasing the static water contact angle.

[0023] The silane-modified resin of the present invention is used as the base resin for preparing the silane-modified sealant, and the cyclohexane polyacid derivative is used as the environmentally friendly plasticizer, and the prepared silane-modified sealant does not contain o-phthalate plasticizers. The environmentally friendly plasticizer ensures the stability of the performance of the silane-modified resin, and enables the prepared green sealant to have the advantages of good sealing performance, strong bonding force, excellent weather resistance and elasticity, and meets the strict requirements of modern society for green and environmentally friendly materials.

[0024] The green and environmentally friendly sealant of the present invention can pass the testing requirements of the amendment directive (EU) 2015 / 863 of Annex II I of the EU RoHS directive 2011 / 65 / EU.

[0025] The invention is scientific and reasonable, has abundant raw materials, is green and environmentally friendly, pollution-free, and easy to produce and prepare. The entire preparation process is easy to operate, fully reflects the friendliness to the environment, and provides a solid and powerful technical support for the sustainable development of the sealant industry. It has good application prospects and is an innovation in the preparation method of silane-modified resin and green and environmentally friendly sealant, and its economic and social benefits are remarkable. DETAILED DESCRIPTION

[0026] The specific implementation modes of the present invention are described in detail below in combination with embodiments and specific situations. Example 1

[0027] (1) 8.8 g of cis-2-butene-1,4-diol and 19.6 g of 3-mercaptopropyltrimethoxysilane (KH590) were weighed into a 50 mL single-necked round-bottom flask, and 0.1642 g of 2,2'-azobisisobutyronitrile (AIBN) was added. The mixture was reacted for 3 h under nitrogen protection to obtain a light yellow liquid, which was HO-Silane.

[0028] (2) Polytetrahydrofuran diol Put it into a four-necked flask equipped with a thermometer, a mechanical stirrer and a vacuum gauge, evacuate to above -0.095MPa, and heat to 105°C for 1.5 hours to remove water in the reactant; under nitrogen protection, cool to 75°C, add 19.6g of isophorone diisocyanate measured with an R value (ratio of -NCO to -OH groups) of 2.2, and then add 0.01% by mass of dibutyltin dilaurate based on the total mass of the feed, heat to 80°C, react for 3.0 hours to obtain a prepolymer; add 8.1g of the prepared HO-Silane and 0.01% by mass of dibutyltin dilaurate based on the total mass of the feed to the reaction system, react at 80°C for 3.0 hours under nitrogen protection, and cool to 25°C to obtain a silane-modified resin.

[0029] (3) After adding 10.125 g of catalyst and 20.375 g of catalyst to 25.0 g of resin, the mixture was placed in a vacuum degassing disperser and dispersed for 2 min; the silane-modified resin was then spread on a polytetrafluoroethylene (PTFE) mold plate, and the remainder was smeared on a substrate with a scraper (the smearing specification was 25 mm×12.5 mm). The polytetrafluoroethylene mold plate and the substrate were then cured at (23±2)°C and (50±5)% relative humidity for 7 days, and then tensile strength, elongation at break and shear strength were tested. Embodiments 2 to 7

[0030] The difference from Example 1 is that the R values ​​of Examples 2-5 are 2.4, 2.6, 2.8 and 3.0 respectively. Table 1 The proportion of isophorone diisocyanate (IPDI) and HO-Silane in Examples 1-5

[0031] The performance test results of the silane-modified resin prepared by the above embodiment and the elastomer formed after moisture curing are shown in the following table: Table 2 Performance indicators of the elastomer formed after silane-modified resin and moisture curing in Examples 1-5 Example 6

[0032] A green and environmentally friendly silane-modified sealant is measured by the following weight parts: 15 parts of the silane-modified resin in Example 1; 22 parts of environmentally friendly plasticizer: cyclohexane 1,2-dioctyl dicarboxylate; 35 parts of nano calcium carbonate; 23 parts of active heavy calcium; 2 parts of white pulp; 11 parts of coupling agent: KH-17; 1 part of coupling agent: KH-560; 0.5 parts of ultraviolet light absorber; 0.5 parts of light stabilizer; and 0.1 parts of catalyst: chelating agent. The specific steps are as follows: (1) mixing silane-modified resin, plasticizer, nano calcium carbonate and active heavy calcium in a power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (2) adding coupling agent, ultraviolet light absorber and light stabilizer to the double planetary power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (3) adding catalyst to the double planetary power mixer under nitrogen protection, stirring at high speed for 10 minutes at 25°C, and vacuum degassing, and packaging to obtain green and environmentally friendly sealant. Example 7

[0033] A green and environmentally friendly silane-modified sealant is measured by the following weight parts: 20 parts of the silane-modified resin in Example 1; 20 parts of environmentally friendly plasticizer: cyclohexane 1,2-dioctyl dicarboxylate; 38 parts of nano calcium carbonate; 17 parts of active heavy calcium; 2 parts of white pulp; 11 parts of coupling agent: KH-17; 1 part of coupling agent: KH-560; 0.5 parts of ultraviolet light absorber (Tinuvin770); 0.5 parts of light stabilizer (Tinuvin328); 0.1 parts of catalyst: chelating agent. The specific steps are as follows: (1) mixing silane-modified resin, plasticizer, nano calcium carbonate and active heavy calcium in a power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (2) adding coupling agent, ultraviolet light absorber and light stabilizer to the double planetary power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (3) adding catalyst to the double planetary power mixer under nitrogen protection, stirring at high speed for 10 minutes at 25°C, and vacuum degassing, and packaging to obtain green and environmentally friendly sealant. Example 8

[0034] A green and environmentally friendly silane-modified sealant is measured by the following weight parts: 25 parts of the silane-modified resin in Example 1; 20 parts of environmentally friendly plasticizer: cyclohexane 1,2-dioctyl dicarboxylate; 45 parts of nano calcium carbonate; 5 parts of active heavy calcium; 2 parts of white pulp; 11 parts of coupling agent: KH-17; 1 part of coupling agent: KH-560; 0.5 parts of ultraviolet light absorber; 0.5 parts of light stabilizer; and 0.1 parts of catalyst: chelating agent. The specific steps are as follows: (1) mixing silane-modified resin, plasticizer, nano calcium carbonate and active heavy calcium in a power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (2) adding coupling agent, ultraviolet light absorber and light stabilizer to the double planetary power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (3) adding catalyst to the double planetary power mixer under nitrogen protection, stirring at high speed for 10 minutes at 25°C, and vacuum degassing, and packaging to obtain green and environmentally friendly sealant. Example 9

[0035] A green and environmentally friendly silane-modified sealant is measured by the following weight parts: 25 parts of silane-modified resin in Example 1; 20 parts of environmentally friendly plasticizer: cyclohexane 1,2-dioctyl dicarboxylate; 35 parts of nano calcium carbonate; 12 parts of active heavy calcium; 3 parts of fumed silica; 2 parts of white slurry; 11 parts of coupling agent: KH-17; 1 part of coupling agent: KH-560; 0.5 parts of ultraviolet light absorber; 0.5 parts of light stabilizer; and 0.1 parts of catalyst: chelating agent. The specific steps are as follows: (1) mixing silane-modified resin, plasticizer, nano calcium carbonate and active heavy calcium in a power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (2) adding coupling agent, ultraviolet light absorber and light stabilizer to the double planetary power mixer, stirring at high speed for 10 minutes at 25°C, and vacuum degassing; (3) adding catalyst to the double planetary power mixer under nitrogen protection, stirring at high speed for 10 minutes at 25°C, and vacuum degassing, and packaging to obtain green and environmentally friendly sealant. Table 2 Performance indicators of green environmentally friendly sealants in Examples 6-8 Table 3 Environmental performance indicators of green environmentally friendly sealants in Examples 6-8

Claims

1. A method for preparing a silane-modified resin and a green environmentally friendly sealant, characterized in that: Includes the following Preparation steps: (1) Add cis-2-butene-1,4-diol and 3-mercaptopropyltrimethoxysilane (KH590) into a reaction kettle, add 2,2'-azobisisobutyronitrile (AIBN) under continuous stirring, and react at 78-85° C. for 3.0-3.5 hours under nitrogen protection to obtain the product 2-((3-(trimethoxysilyl)propyl)thio)butane-1,4-diol (HO-Silane); wherein the molar ratio of cis-2-butene-1,4-diol, KH590, and AIBN is 1:1:0.005-0.

001. (2) Put the polyol into a four-necked flask equipped with a thermometer, a mechanical stirrer and a vacuum gauge, evacuate to above -0.095 MPa, and heat to 100-110° C., and keep for 1.5-2 hours to remove water in the reactants; under nitrogen protection, cool to 70-80° C., add isocyanate with an R value (ratio of -NCO to -OH groups) of 2.0-3.0, and then add 0.001% to 0.01% by mass of catalyst 1 based on the total mass of the feed, heat to 80-85° C., and react for 2.5-3.0 hours to obtain a prepolymer; (3) Add the prepared HO-Silane to the reaction system, and then add 0.001% to 0.01% of the total mass of the feed catalyst 1, react at 80° C. for 2.5 to 3.0 hours under nitrogen protection, and then reduce the temperature to 25° C. to obtain a silane-modified resin; The amount of HO-Silane is calculated based on the mass of the polyol. For every 100 mass parts of the polyol, 9 to 18 mass parts of HO-Silane are added. (4) Mix the silane modified resin, environmentally friendly plasticizer and inorganic filler in a double planetary power mixer, and stir at a high speed of less than 80° C. for 10 minutes under nitrogen protection; add coupling agent 1, coupling agent 2, ultraviolet light absorber and light stabilizer to the mixer, and stir at a high speed of less than 80° C. for 10 minutes under nitrogen protection; add catalyst 2 to the mixer, and stir at a high speed of less than 80° C. for 10 minutes under nitrogen protection, vacuum degassing, and packaging to obtain a green environmentally friendly sealant; the total amount is measured according to the following mass parts per 100 mass parts: 15-35 parts of silane modified resin, 15-25 parts of environmentally friendly plasticizer, 35-65 parts of inorganic filler, 0.5-1 part of coupling agent 1, and 0.5-1 part of coupling agent 2; 0-0.5 parts of ultraviolet light absorber, 0-0.5 parts of light stabilizer, and 0.01-1 parts of catalyst 2.

2. The method for preparing a silane-modified resin and a green environmentally friendly sealant according to claim 1, characterized in that: The polyol is polyoxypropylene diol, polytetrahydrofuran diol, polypropylene carbonate diol, one or a mixture of the two or more, and the molecular weight is 1000-2000 g / mol.

3. The method for preparing a silane-modified resin and a green environmentally friendly sealant according to claim 1, characterized in that: The diisocyanate is an isocyanate that does not contain benzene series, including cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, one or a mixture of several.

4. The method for preparing a silane-modified resin and a green environmentally friendly sealant according to claim 1, characterized in that: The catalyst 1 is one of dibutyltin dilaurate and dibutyltin dichloride or a mixture of the two; the catalyst 2 is chelated tin (360).

5. The method for preparing a silane-modified resin and a green environmentally friendly sealant according to claim 1, characterized in that: The coupling agent 1 is (KH-171); the coupling agent 2 is (KH-560).

6. The method for preparing a silane-modified resin and a green environmentally friendly sealant according to claim 1, wherein: The environmentally friendly plasticizer is a cyclohexane polyacid derivative, including dioctyl cyclohexane 1,2-dicarboxylate (DEHCH), dibutyl cyclohexane 1,2-dicarboxylate (DBCH), diisobutyl cyclohexane 1,2-dicarboxylate (DIBCH), diisononyl cyclohexane 1,2-dicarboxylate (DINCH), di(2-propylheptyl) cyclohexane 1,2-carboxylate (DPHCH), and diisodecyl cyclohexane 1,2-dicarboxylate (DIDCH), one or more of which can be used in combination.

7. The method for preparing a silane-modified resin and a green environmentally friendly sealant according to claim 1, characterized in that: It is stated The inorganic filler is nano calcium carbonate, active calcium carbonate, talcum powder, titanium dioxide, gas silica, molecular sieve, one or a mixture of them.

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