Preparation method of hyperbranched polyether modified organosilicon coating leveling agent

Abstract

The invention relates to a preparation method of a hyperbranched polyether modified organic silicon coating leveling agent, which comprises the following steps: reacting pentaerythritol glycidyl ether with unsaturated polyether under the action of a base catalyst to obtain a branched intermediate, and continuously reacting with hydrogen-containing silicone oil under the action of a chloroplatinic acid catalyst to obtain the hyperbranched modified organic silicon leveling agent. The hyperbranched organic silicon leveling agent has a specific structure, a carbon-oxygen chain is taken as a main structural chain, the compatibility of the leveling agent and an interface material is improved, and meanwhile, hydrogen-containing silicone oil with low hydrogen content and low molecular weight is introduced in a branching reaction, so that the problems that the leveling agent is poor in leveling performance and low in slippery feeling are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of coating leveling agents, and in particular to a polyether modified organic silicon leveling agent. Background Art

[0002] As the country pays more and more attention to green environmental protection, all walks of life are committed to improving the environmental protection indicators of products. Paints, as common industrial products, are widely used in construction, home appliances, wood products, plastics and other industries. Among them, water-based paints are one of the main directions of paint development. However, compared with oil-based paints, water-based paints are more prone to orange peel, shrinkage, ripples, floating color, brush marks, roller marks, sagging and other drawbacks on the surface of the coating film. These drawbacks are all related to the surface tension of the coating system. Surface tension is the main driving force for the flow and leveling of the coating film. Therefore, if you want to control the surface state of the coating film, you must control and adjust the surface tension of the coating film.

[0003] Leveling agent is a commonly used coating additive. It can help the coating form a flat, smooth and uniform coating during the drying process, effectively reduce the surface tension of the coating liquid, and improve its leveling and uniformity. Depending on the type of coating, the type of leveling agent is also different. According to the different chemical structures, there are three main types of leveling agents: acrylic Acids, silicones and fluorocarbon compounds. Among them, silicone leveling agents can improve leveling and gloss, reduce the interfacial tension between the coating and the substrate, improve the wetting of the substrate, and reduce surface pathologies of the coating such as shrinkage cavities. CN111116922A discloses a phosphorus-containing polyether modified silicone leveling agent, which comprises phosphorus-containing polyether modified silicone. It has both good leveling properties and water solubility, and is particularly suitable for water-based coatings. The dispersibility and water solubility of the leveling agent are improved, and the compatibility needs to be improved; CN112831003A provides a polyether-modified silicone leveling agent with an anchoring group and a fluorocarbon side chain and a preparation method thereof. The leveling agent is a polyether-modified silicone leveling agent with an anchoring group, a fluorocarbon side chain and a polyether side chain prepared by a hydrosilylation reaction of allyl polyether, fluoroacrylate, acrylamide and hydrogen-containing silicone oil. Polysiloxane, in which the amine group is an anchoring group, has good affinity with the pigment, the fluorocarbon side chain promotes the wetting of the substrate and eliminates shrinkage holes, and the polyether side chain has good compatibility with most coating systems. This patent introduces fluorocarbon side chains, and the manufacturing cost is relatively high; CN114276548A and CN105585715A use allyl alcohol polyether and hydrogen-containing silicone oil as raw materials, chloroplatinic acid as a catalyst, and adopt the method of silicon hydrogen and allyl addition to prepare the product. The polyether silicone leveling agent has the functions of a wetting agent, a dispersant and a defoaming agent. Although the leveling agent takes into account various functions, its leveling performance and compatibility still need to be improved. Summary of the invention

[0004] The invention relates to a method for preparing a hyperbranched polyether modified organic silicon coating leveling agent. Firstly, pentaerythritol glycidyl ether and unsaturated polyether are reacted under the action of an alkali catalyst to obtain a branched intermediate, and then the intermediate is reacted with hydrogen-containing silicone oil under the action of chloroplatinic acid catalyst to obtain a hyperbranched modified organic silicon leveling agent. The hyperbranched organic silicon leveling agent has a specific structure, with a carbon-oxygen chain as the main structural chain, thereby improving the compatibility of the leveling agent with an interface material. Meanwhile, a branching reaction introduces low-hydrogen-containing and low-molecular-weight hydrogen-containing silicone oil, thereby effectively overcoming the problems of poor leveling performance and reduced slipperiness of the leveling agent.

[0005] Technical Solution A method for preparing a hyperbranched polyether modified silicone coating leveling agent, the preparation method is as follows: (1) heating pentaerythritol glycidyl ether and unsaturated polyether to react under the action of a base catalyst to prepare a branched intermediate; (2) Continue to mix the branched intermediate and hydrogen-containing silicone oil evenly, slowly add the platinum catalyst dropwise under the condition of increasing temperature, and continue the reaction after the addition is completed to obtain the final hyperbranched polyether modified silicone coating leveling agent.

[0006] in: The structural formula of the unsaturated polyether in step (1) is: CH 2 =CH-(OCH2CH2) n OH, n is an integer from 3 to 10; The molar ratio of pentaerythritol glycidyl ether to unsaturated polyether is 1:2-4; The amount of the base catalyst used is 0.5%-1% of the total mass of pentaerythritol glycidyl ether and unsaturated polyether; The base catalyst is selected from sodium hydroxide, potassium hydroxide, potassium silanolate, sodium silanolate, sodium methoxide, potassium methoxide, potassium ethoxide, and tetramethylammonium hydroxide; The reaction temperature is 70-120°C and the reaction time is 0.5-2h; The structural formula of the hydrogenated silicone oil in step (2) is: HMe 2 Si(SiR 1 HO) d (SiR 2 2 O) e SiMe 2 H, R 1 , R 2 are the same or different and are selected from methyl, ethyl, n-propyl, n-butyl, isobutyl, and n-pentyl; subscript d is an integer of 5-20, and e is an integer of 50-200; The molar ratio of hydrogen groups in the hydrogen-containing silicone oil to propylene groups in the unsaturated polyether is 1-1.2:1; The amount of platinum catalyst used is 3-20 ppm (in terms of platinum) based on the total mass of the branched intermediate and the hydrogen-containing silicone oil; The platinum catalyst is selected from platinum-alcohol complex, platinum-olefin complex, platinum-alkoxide complex, platinum-ether complex, platinum-ketone complex, and chloroplatinic acid isopropanol solution; The reaction temperature is 70-100°C, the reaction time is 0.5-2h, and the dropwise addition time is controlled between 0.5-1h. DETAILED DESCRIPTION Example 1

[0008] (1) 36 g of pentaerythritol glycidyl ether and 35.2 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 3 OH was heated to 70°C under the action of 0.36 g of sodium hydroxide as a base catalyst and reacted for 2 h to prepare a branched intermediate; (2) Continue to combine the branched intermediate and 366.36 hydrogenated silicone oil HMe 2 Si(HSiCH 3 O) 10 (SiCH 3 C 2 H 5 O) 200 SiMe 2 H were mixed evenly, and chloroplatinic acid isopropanol solution was slowly added dropwise at 80°C. After the addition was completed within 1 hour, the reaction was continued for 1.5 hours to obtain the final hyperbranched polyether modified silicone coating leveling agent. Example 2

[0009] (1) 36 g of pentaerythritol glycidyl ether and 79.2 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 5 OH was heated to 80°C under the action of 0.92g of the base catalyst potassium silanolate for 1h to prepare a branched intermediate; (2) Continue to mix the branched intermediate and 547.9g of hydrogenated silicone oil HMe 2 Si(HSiC 3 H 7 O) 5 (SiCH 3 C 5 H 11 O) 80 SiMe 2H was mixed evenly, and the platinum-olefin complex was slowly added dropwise at 100°C. After the addition was completed within 1 hour, the reaction was continued for 0.5 hour to obtain the final hyperbranched polyether modified silicone coating leveling agent. Example 3

[0010] (1) 36 g of pentaerythritol glycidyl ether and 140.8 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 7 OH was heated to 100°C under the action of 0.11 g of sodium methoxide as a base catalyst and reacted for 1 h to prepare a branched intermediate; (2) Continue to mix the branched intermediate and 248.85g of hydrogenated silicone oil HMe 2 Si(HSiC 2 H 5 O) 14 (SiCH 3 C 2 H 5 O) 100 SiMe 2 H were mixed evenly, and the platinum-ether complex was slowly added dropwise at 90°C. After the addition was completed within 0.5 h, the reaction was continued for 1 h to obtain the final hyperbranched polyether modified silicone coating leveling agent. Example 4

[0011] (1) 36 g of pentaerythritol glycidyl ether and 88 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 10 OH was heated to 120°C under the action of 0.12 g of base catalyst potassium ethoxide for 0.5 h to prepare a branched intermediate; (2) Continue to mix the branched intermediate and 71.18g of hydrogenated silicone oil HMe 2 Si(HSiCH 3 O) 20 (SiCH 3 C 4 H 9 O) 50 SiMe 2 H was mixed evenly, and the platinum-ketone complex was slowly added dropwise at 80°C. After the addition was completed within 1 hour, the reaction was continued for 1.5 hours to obtain the final hyperbranched polyether modified silicone coating leveling agent. Example 5

[0012] (1) 36 g of pentaerythritol glycidyl ether and 118.8 g of unsaturated polyether CH 2 =CH-(OCH 2 CH2 ) 8 OH was heated to 90°C under the action of 0.14 g of tetramethylammonium hydroxide as a base catalyst and reacted for 1 h to prepare a branched intermediate; (2) Continue to mix the branched intermediate and 221.22g of hydrogenated silicone oil HMe 2 Si(HSiCH 3 O) 20 (SiCH 3 CH 3 O) 150 SiMe 2 H were mixed evenly, and the platinum-alkoxide complex was slowly added dropwise at 70°C. After the addition was completed within 0.5 h, the reaction was continued for 2 h to obtain the final hyperbranched polyether modified silicone coating leveling agent.

[0013] Comparative Example 1 (1) 36 g of allyl glycidyl ether and 35.2 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 3 OH was heated to 70°C under the action of 0.36 g of sodium hydroxide as a base catalyst and reacted for 2 h to prepare a branched intermediate; (2) Continue to combine the branched intermediate and 366.36 hydrogenated silicone oil HMe 2 Si(HSiCH 3 O) 10 (SiCH 3 C 2 H 5 O) 200 SiMe 2 H were mixed evenly, and chloroplatinic acid isopropanol solution was slowly added dropwise at 80°C. After the addition was completed within 1 hour, the reaction was continued for 1.5 hours to obtain the final hyperbranched polyether modified silicone coating leveling agent.

[0014] Comparative Example 2 (1) 36 g of polypropylene glycol glycidyl ether and 79.2 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 5 OH was heated to 80°C under the action of 0.92g of the base catalyst potassium silanolate for 1h to prepare a branched intermediate; (2) Continue to mix the branched intermediate and 547.9g of hydrogenated silicone oil HMe 2 Si(HSiC 3 H 7 O) 5 (SiCH 3 C 5 H11 O) 80 SiMe 2 H was mixed evenly, and the platinum-olefin complex was slowly added dropwise at 100°C. After the addition was completed within 1 hour, the reaction was continued for 0.5 hour to obtain the final hyperbranched polyether modified silicone coating leveling agent.

[0015] Comparative Example 3 (1) 36 g of 1,4-butanediol glycidyl ether and 140.8 g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 7 OH was heated to 100°C under the action of 0.11 g of sodium methoxide as a base catalyst and reacted for 1 h to prepare a branched intermediate; (2) Continue to mix the branched intermediate and 248.85g of hydrogenated silicone oil HMe 2 Si(HSiC 2 H 5 O) 14 (SiCH 3 C 2 H 5 O) 100 SiMe 2 H were mixed evenly, and the platinum-ether complex was slowly added dropwise at 90°C. After the addition was completed within 0.5 h, the reaction was continued for 1 h to obtain the final hyperbranched polyether modified silicone coating leveling agent.

[0016] Comparative Example 4 88g of unsaturated polyether CH 2 =CH-(OCH 2 CH 2 ) 10 OH and 71.18g hydrogen silicone oil HMe 2 Si(HSiCH 3 O) 20 (SiCH 3 C 4 H 9 O) 50 SiMe 2 H was mixed evenly, and the platinum-ketone complex was slowly added dropwise at 80°C. After the addition was completed within 1 hour, the reaction was continued for 1.5 hours to obtain the final hyperbranched polyether modified silicone coating leveling agent.

[0017] Performance Testing Add 150g of laboratory self-prepared varnish into a 1000ml stainless steel cup, then add 0.05g of leveling agent, and use a sample without leveling agent as a blank sample. Use a laboratory high-speed disperser to disperse at a speed of 500r / min for 5 minutes, stop and let it stand for 10 minutes, take out a small amount and place it on a glass plate, use a 75um wet film preparation device to scrape the paint at a uniform speed, judge the flatness and transparency of the coating, and make a record. The smaller the number of leveling performance, the better the leveling performance; the higher the shrinkage level, the better the compatibility.

[0018] Coating grade classification

[0019] Test Results

Claims

1. A method for preparing a hyperbranched polyether modified silicone coating leveling agent, characterized in that: The preparation method is as follows: (1) heating pentaerythritol glycidyl ether and unsaturated polyether to react under the action of a base catalyst to prepare a branched intermediate; (2) Continue to mix the branched intermediate and hydrogen-containing silicone oil evenly, slowly add the platinum catalyst dropwise under the condition of increasing temperature, and continue the reaction after the addition is completed to obtain the final hyperbranched polyether modified silicone coating leveling agent.

2. The method for preparing a hyperbranched polyether-modified silicone coating leveling agent according to claim 1, characterized in that: In step (1), the structural formula of the unsaturated polyether is: CH2=CH-(OCH2CH2) n OH, n is an integer of 3-10.

3. The method for preparing a hyperbranched polyether-modified silicone coating leveling agent according to claim 1, characterized in that: In step (1), the molar ratio of pentaerythritol glycidyl ether to unsaturated polyether is 1:2-4; and the amount of the base catalyst used accounts for 0.5%-1% of the total mass of pentaerythritol glycidyl ether and unsaturated polyether.

4. The method for preparing a hyperbranched polyether modified silicone coating leveling agent according to claim 1, characterized in that: In step (1), the base catalyst is selected from sodium hydroxide, potassium hydroxide, potassium silanolate, sodium silanolate, sodium methoxide, potassium methoxide, potassium ethoxide, and tetramethylammonium hydroxide.

5. The method for preparing a hyperbranched polyether-modified silicone coating leveling agent according to claim 1, characterized in that: In step (1), the reaction temperature is 70-120°C and the reaction time is 0.5-2h.

6. The method for preparing a hyperbranched polyether modified silicone coating leveling agent according to claim 1, characterized in that: In step (2), the structural formula of hydrogen-containing silicone oil is: HMe2Si(SiR 1 HO) d (SiR 2 2O) e SiMe2H,R 1 , R 2 are the same or different and are selected from methyl, ethyl, n-propyl, n-butyl, isobutyl and n-pentyl; subscript d is an integer of 5-20, and e is an integer of 50-200.

7. The method for preparing a hyperbranched polyether-modified silicone coating leveling agent according to claim 1, characterized in that: In step (2), the molar ratio of hydrogen groups in the hydrogen-containing silicone oil to propenyl groups in the unsaturated polyether is 1-1.2:1; and the amount of platinum catalyst used is 3-20 ppm of the total mass of the branched intermediate and the hydrogen-containing silicone oil, calculated as platinum.

8. The method for preparing a hyperbranched polyether-modified silicone coating leveling agent according to claim 1, characterized in that: In step (2), the platinum catalyst is selected from platinum-alcohol complex, platinum-olefin complex, platinum-alkoxide complex, platinum-ether complex, platinum-ketone complex, and chloroplatinic acid isopropanol solution.

9. The method for preparing a hyperbranched polyether-modified organosilicon coating leveling agent according to claim 1, characterized in that: In step (2), the reaction temperature is 70-100°C, the reaction time is 0.5-2h, and the dropwise addition time is controlled between 0.5-1h.

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