Environment-friendly silicon resin hybrid composite emulsion and preparation method thereof

Abstract

The invention belongs to the technical field of industrial coatings, and particularly relates to an environment-friendly silicon resin hybrid composite emulsion and a preparation method thereof, and the preparation method comprises the following steps: synthesis of hydroxyl butenelactone, synthesis of alkoxy butenelactone, synthesis of a copolymer emulsion, preparation of a dropwise added mixed solution, and preparation of the silicon resin hybrid composite emulsion. The problem of high VOC content of the existing high-temperature-resistant silicon resin emulsion is solved, high solid content and excellent high-temperature resistance of the silicon resin emulsion can be realized, and the application requirements of environment-friendly high-temperature-resistant water-based paint are met.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial coatings, and in particular relates to an environmentally friendly silicone hybrid composite emulsion and a preparation method thereof. Background Art

[0002] With the increasing global awareness of environmental protection, the traditional industrial coatings industry is facing unprecedented challenges and opportunities. Environmentally friendly coatings, with their low pollution and low emission characteristics, have become an indispensable part of green coatings and sustainable development strategies. Based on the utilization of renewable resources and the demand for waste-free, low-energy chemical conversion materials for the future design of green chemical products, countries around the world are working hard to develop and find new alternatives.

[0003] The synthesis of acrylates, which are commonly used in the coatings industry, usually uses a multi-step process, where medium-chain to long-chain fossil hydrocarbons are converted into olefins through cracking, further oxidized and derived into acrylates, and then polymerized to produce various resins and coatings. Currently, the annual production of acrylates in the world exceeds 3.5 million tons. The present invention seeks alternatives based on renewable resources while having good properties like acrylates, which will bring great changes to the future chemical and material fields. Although the use of renewable raw materials has made progress in fuels, polymers and specialty chemicals, direct bio-based alternatives to acrylic coatings remain largely undeveloped. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an environmentally friendly silicone resin hybrid composite emulsion and a preparation method thereof.

[0005] The present invention is achieved by providing a method for preparing an environmentally friendly silicone hybrid composite emulsion, comprising the following steps: Step 1: Synthesis of hydroxybutenolide; Furfural, methylene blue and methanol were added to a rotary evaporator with oxygen, irradiated with light for 20 minutes, the solvent methanol was removed by reduced pressure distillation, and the photosensitizer methylene blue was removed by filtration to generate an off-white crystalline solid product, namely hydroxybutenolide; Step 2: Synthesis of alkoxybutenolide; The hydroxybutenolide is dissolved in methanol, heated under reflux for 20 hours until all the hydroxybutenolide is consumed, and the methanol is removed by distillation under reduced pressure to obtain the alkoxybutenolide; Step 3: Synthesis of copolymer emulsion; By adopting the copolymerization method, alkoxy butene lactone and tert-butylene carbonate are added into the reactor, propylene glycol methyl ether is used as solvent, 0.5% Trigonox42S is used as free radical initiator, and the mixture is heated under reflux at 120°C to obtain copolymer emulsion after 2 hours. Step 4: Preparation of dropwise mixed solution; Add two or more siloxane monomers, a silane coupling agent and water into a dropping container, mix them evenly, and form a dropping mixed liquid; Step 5: Preparation of silicone hybrid composite emulsion; Add the copolymer emulsion into the kettle, stir at room temperature, adjust the pH to alkaline with ammonia water, heat to 50°C, and then drop the mixed solution prepared in step 4 into the kettle, control the dropping time to 4h, keep warm for 4h, then cool down, neutralize to neutral pH, filter the reactants, and obtain a silicone resin hybrid composite emulsion.

[0006] Preferably, in step 1, the mass ratio of furfural, methylene blue and methanol is 8-10:1-2:10.

[0007] Preferably, in step 2, the mass ratio of hydroxybutene lactone to methanol is 1:5.

[0008] Preferably, in step three, the mass ratio of alkoxybutene lactone to versatate vinyl carbonate is 1:1.

[0009] Preferably, in step 4, the mass ratio of siloxane monomer, silane coupling agent and water is 10-40:8-22:100.

[0010] Preferably, in step five, the pH is adjusted to 8 with aqueous ammonia and filtered with a 200-mesh sieve.

[0011] The present invention also provides an environmentally friendly silicone hybrid composite emulsion, which is prepared based on the above method.

[0012] Compared with the prior art, the advantages of the present invention are: The present invention provides an environmentally friendly silicone resin hybrid composite emulsion and a preparation method thereof, which solves the problem of high VOC content in existing high-temperature resistant silicone resin emulsions, while also achieving high solid content in the silicone resin emulsion, meeting the application requirements of environmentally friendly high-temperature resistant water-based coatings. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] The present invention provides a method for preparing an environmentally friendly silicone resin hybrid composite emulsion. The synthesis of the copolymer emulsion comprises the following steps: Step 1: Synthesis of hydroxybutenolide; Furfural, methylene blue and methanol in a mass ratio of 8-10:1-2:10 are added to a rotary evaporator with oxygen, and irradiated with light for 20 minutes, the solvent methanol is removed by reduced pressure distillation, and the photosensitizer methylene blue is removed by filtration to generate an off-white crystalline solid product, namely hydroxybutenolide; Step 2: Synthesis of alkoxybutenolide; Dissolve hydroxybutenolide in methanol, the mass ratio of hydroxybutenolide to methanol is 1:5, reflux and heat for 20 hours until all the hydroxybutenolide is consumed, and remove the methanol by distillation under reduced pressure to obtain alkoxybutenolide; Step 3: Synthesis of copolymer emulsion; By using a copolymerization method, alkoxybutene lactone and tert-butylene carbonate in a mass ratio of 1:1 were added into a reactor, propylene glycol methyl ether was used as a solvent, 0.5% of Trigonox42S was used as a free radical initiator, and the mixture was heated under reflux at 120°C to obtain a copolymer emulsion after 2 hours.

[0015] The following examples provide examples of preparing an environmentally friendly silicone hybrid composite emulsion using a copolymer emulsion prepared by the above method:

[0016] Example 1

[0017] At room temperature, 30.0 g of the copolymer emulsion was added to the reactor, stirred and dispersed evenly, and the pH of the system was controlled to 8 with ammonia water; the temperature was raised to 50°C; 8.0 g of dimethyldimethoxysilane, 3.0 g of tetraethoxysilane, 0.5 g of hexamethyldisiloxane, 22 g of KH560 and 100 g of water were added dropwise to the reactor, and the total dropping time was controlled to be 4 h; then, the reaction was continued to be kept warm for 4 h; after cooling to room temperature, the pH of the emulsion system was adjusted to 7 by neutralization with hydrochloric acid; the reactants were filtered with a 200-mesh sieve to obtain a silicone resin hybrid composite emulsion.

[0018] Example 2

[0019] At room temperature, 30.0 g of the copolymer emulsion was added to the reactor, stirred and dispersed evenly, and the pH of the system was controlled to 8 with ammonia water; the temperature was raised to 50°C; 10.0 g of dimethyldimethoxysilane, 5.0 g of tetraethoxysilane, 0.5 g of hexamethyldisiloxane, 20 g of KH560 and 100 g of water were added dropwise to the reactor, and the total dropping time was controlled to be 4 h; then, the reaction was continued to be kept warm for 4 h; after cooling to room temperature, the pH of the emulsion system was adjusted to 7 by neutralization with hydrochloric acid; the reactants were filtered through a 200-mesh sieve to obtain a silicone resin hybrid composite emulsion.

[0020] Example 3

[0021] At room temperature, 30.0 g of the copolymer emulsion was added to a reactor, stirred and dispersed evenly, and the pH of the system was controlled to 8 with ammonia water; the temperature was raised to 50°C; 8.0 g of dimethyldimethoxysilane, 20.0 g of methyltriethoxysilane, 3.0 g of tetraethoxysilane, 0.5 g of hexamethyldisiloxane, 12 g of KH560 and 100 g of water were added dropwise to the reactor, and the total dropping time was controlled to be 4 h; then, the reaction was continued to be kept warm for 4 h; after cooling to room temperature, the pH of the emulsion system was adjusted to 7 by neutralization with hydrochloric acid; the reactants were filtered through a 200-mesh sieve to obtain a silicone resin hybrid composite emulsion.

[0022] Example 4

[0023] At room temperature, 30.0 g of the copolymer emulsion was added to the reactor, stirred and dispersed evenly, and the pH of the system was controlled to 8 with ammonia water; the temperature was raised to 50°C; 10.0 g of dimethyldimethoxysilane, 25.0 g of methyltriethoxysilane, 2.0 g of tetraethoxysilane, 0.5 g of hexamethyldisiloxane, 8 g of KH560 and 100 g of water were added dropwise to the reactor, and the total dropping time was controlled to be 4 h; then, the reaction was continued to be kept warm for 4 h; after cooling to room temperature, the pH of the emulsion system was adjusted to 7 by neutralization with hydrochloric acid; the reactants were filtered through a 200-mesh sieve to obtain a silicone resin hybrid composite emulsion.

[0024] The solid content of the products prepared in Examples 1-4 was calculated as follows: solid content (%) = total mass of solid matter / total mass of raw materials × 100%). The results are shown in Table 1. It can be seen from the results in Table 1 that the solid content of the products is greater than 40%, and the VOC content of the products detected by gas chromatography is less than 1 g / L.

[0025] Table 1

Claims

1. A method for preparing an environmentally friendly silicone resin hybrid composite emulsion, characterized in that: The steps include: Step 1: Synthesis of hydroxybutenolide; Furfural, methylene blue and methanol were added to a rotary evaporator with oxygen, irradiated with light for 20 minutes, the solvent methanol was removed by reduced pressure distillation, and the photosensitizer methylene blue was removed by filtration to generate an off-white crystalline solid product, namely hydroxybutenolide; Step 2: Synthesis of alkoxybutenolide; The hydroxybutenolide is dissolved in methanol, heated under reflux for 20 hours until all the hydroxybutenolide is consumed, and the methanol is removed by distillation under reduced pressure to obtain the alkoxybutenolide; Step 3: Synthesis of copolymer emulsion; By adopting the copolymerization method, alkoxy butene lactone and tert-butylene carbonate are added into the reactor, propylene glycol methyl ether is used as solvent, 0.5% Trigonox42S is used as free radical initiator, and the mixture is heated under reflux at 120°C to obtain copolymer emulsion after 2 hours. Step 4: Preparation of dropwise mixed solution; Add two or more siloxane monomers, a silane coupling agent and water into a dropping container, mix them evenly, and form a dropping mixed liquid; Step 5: Preparation of silicone hybrid composite emulsion; Add the copolymer emulsion into the kettle, stir at room temperature, adjust the pH to alkaline with ammonia water, heat to 50°C, and then drop the mixed solution prepared in step 4 into the kettle, control the dropping time to 4h, keep warm for 4h, then cool down, neutralize to neutral pH, filter the reactants, and obtain a silicone resin hybrid composite emulsion.

2. The method for preparing the environmentally friendly silicone hybrid composite emulsion according to claim 1, characterized in that: In the step 1, the mass ratio of furfural, methylene blue and methanol is 8-10:1-2:

10.

3. The method for preparing the environmentally friendly silicone resin hybrid composite emulsion according to claim 1, characterized in that: In the step 2, the mass ratio of hydroxybutenolide to methanol is 1:

5.

4. The method for preparing the environmentally friendly silicone resin hybrid composite emulsion according to claim 1, characterized in that: In the step 3, the mass ratio of alkoxybutene lactone to versatate vinyl carbonate is 1:

1.

5. The method for preparing the environmentally friendly silicone hybrid composite emulsion according to claim 1, characterized in that: In the step 4, the mass ratio of the siloxane monomer, the silane coupling agent and water is 10-40:8-22:

100.

6. The method for preparing the environmentally friendly silicone hybrid composite emulsion according to claim 1, characterized in that: In the step 5, the pH value is adjusted to 8 with aqueous ammonia, and the mixture is filtered with a 200-mesh sieve.

7. An environmentally friendly silicone hybrid composite emulsion, characterized in that: It is prepared based on the method described in any one of claims 1 to 6.

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