Star polymer modified polyether organic silicon defoaming agent and preparation method thereof

Abstract

The invention discloses a star polymer modified polyether organic silicon defoaming agent and a preparation method thereof. The star polymer modified polyether organic silicon defoaming agent is prepared from the following raw materials in parts by weight: 15 to 20 parts of active fumed silica, 80 to 85 parts of polyether modified organic silicon, 3 to 9 parts of BASF ST2410, 15 to 22 parts of BASF ST2437 and 10 to 20 parts of a span-Tween compound emulsifier. By using the star polymer modified polyether organic silicon defoaming agent 334 disclosed by the invention, a coating has outstanding defoaming and foam inhibition properties in a dispersing and grinding process, and in a system with the high-viscosity emulsion content of more than 40%, when the dosage of the defoaming agent 334 is less than 0.1%, the use requirement is met and the gloss of the paint is not influenced; in the roller coating process, the foam breaking speed is smaller than 3 s, tiny foam removal reaches 95% or above, roller coating is conducted 30 times in a crossed and back-and-forth mode, and the states of a wet film and a dry film are consistent; the defoaming durability is more than 2 years, and the effect is very good.

Description

Technical Field

[0001] The invention belongs to the technical field of polyether organosilicon defoamers, and particularly relates to a star polymer modified polyether organosilicon defoamer and a preparation method thereof. Background Art

[0002] In recent years, technological advancements have placed higher demands on the coatings industry, with foaming being a particularly prominent issue in water-based latex paints. Consequently, the development of a defoamer that can rapidly defoam, permanently suppress foam, eliminate microfoam, and prevent cratering in high-viscosity systems under high shear conditions is urgently needed. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a star-shaped polymer modified polyether silicone defoamer with simple process and low cost and a preparation method thereof. The polyether silicone defoamer produces a synergistic resonance effect through the effective combination of the star-shaped polymer and the homemade modified polyether silicone, thereby overcoming the defects of many current defoamers due to their simple structure, the presence of tiny bubbles that are difficult to eliminate during application, and the presence of shrinkage holes after construction.

[0004] The present invention adopts the following technical solution to solve the above technical problems: a star polymer modified polyether silicone defoamer, characterized in that it is prepared from the following raw materials in parts by weight: 15-20 parts of active fumed silica 80-85 parts of polyether modified silicone BASF ST2410 3-9 parts BASF ST2437 15-22 copies 10-20 parts of Span-Tween composite emulsifier; The formula of Span-Tween composite emulsifier is as follows: Span 20 2-5 servings Span 80 1-3 servings 3-5 parts Tween 40 Tween 80 4-7 parts.

[0005] It is further defined that the specific synthesis process of the polyether-modified silicone is: Step S1: Preparation of low hydrogen silicone oil 100-140 parts by weight of dimethylcyclosiloxane, 8-10 parts by weight of high hydrogen silicone oil, 2.5-3 parts by weight of hexamethyldisiloxane, and 1-2 parts by weight of concentrated sulfuric acid with a concentration higher than 98% are added to a reaction vessel, reacted at 60-65° C. for 4-8 hours, then cooled to room temperature, and then neutralized by adding sodium hydroxide until the reaction system is neutral. The mixture is filtered and then distilled under reduced pressure at below 110° C. to obtain low hydrogen silicone oil with an active hydrogen mass fraction of 0.06%-0.09%. Step S2: Synthesis of terminal allyl polyoxyethylene polyoxypropylene ether 80-100 parts by weight of propylene alcohol and 5-20 parts by weight of sodium bicarbonate are added to an autoclave, nitrogen is filled for protection, the temperature is evacuated and raised to 100-120° C., 8-12 parts by weight of ethylene oxide and propylene oxide are added while stirring, wherein the mass ratio of ethylene oxide to propylene oxide is 15 / 85, and the reaction is carried out until the pressure in the autoclave becomes negative pressure, and the product is cooled and discharged. The product is neutralized, bleached, filtered, and dehydrated to obtain terminal allyl polyoxyethylene polyoxypropylene ether with a molecular weight of 400-600; Step S3: Synthesis of polyether-modified silicone Add 30-50 parts by weight of the low-hydrogen silicone oil obtained in step S1, 50-70 parts by weight of the terminal allyl polyoxyethylene polyoxypropylene ether obtained in step S2, 0.1-0.3 parts by weight of chloroplatinic acid, and 200-300 parts by weight of isopropanol solvent into a reaction kettle, heat to 100-110° C. under nitrogen protection, react for 6-10 hours, and then distill off the isopropanol solvent to obtain a polyether-modified silicone.

[0006] It is further defined that the preparation process of the star-shaped polymer-modified polyether silicone defoamer 334 is as follows: 15-20 parts by weight of active fumed silica, 80-85 parts by weight of polyether-modified silicone, 3-9 parts by weight of BASF ST2410, 15-22 parts by weight of BASF ST2437 and 10-20 parts by weight of Span-Tween composite emulsifier are mixed and stirred at 80-90°C for 2-4 hours, cooled and homogenized in a homogenizer for 20-40 minutes to obtain the star-shaped polymer-modified polyether silicone defoamer 334.

[0007] The present invention has the following advantages and beneficial effects: 1. The star polymer modified polyether silicone defoamer 334 of the present invention has outstanding defoaming and anti-foaming properties during the dispersion and grinding process of the coating. In a system with a high-viscosity emulsion content greater than 40%, a dosage of less than 0.1% of the defoamer 334 meets the usage requirements without affecting the gloss of the paint. 2. During the roller coating process, the bubble breaking speed is less than 3s, and the micro-foam elimination rate reaches more than 95%. After 30 cross-rolling cycles, the wet film and dry film are in the same state. 3. The defoaming effect is very good with a durability of more than 2 years; 4. The star polymer modified polyether silicone defoamer 334 of the present invention is particularly suitable for systems with high viscosity and high emulsion content. DETAILED DESCRIPTION

[0008] The specific technical scheme of the present invention is described in detail with reference to specific embodiments. The preparation principle of the present invention is as follows: first, high-hydrogen silicone oil is used as raw material to produce low-hydrogen silicone oil by telomerization, and simultaneously, propylene oxide and ethylene oxide are ring-opening copolymerized using allyl alcohol as an initiator and sodium hydroxide as a catalyst to produce terminal allyl polyoxyethylene polyoxypropylene ether. The low-hydrogen silicone oil is then grafted with the terminal allyl polyoxyethylene polyoxypropylene ether, and then further bonded with BASF ST2410 and BASF ST2437. The defoaming agent is then prepared by adding active fumed silica, Span 20, Span 80, Tween 40, and Tween 80.

[0009] Raw materials required for the preparation process: dimethylcyclosiloxane (DMC), high hydrogen silicone oil (1%-8%), hexamethyldisiloxane (MM), ethylene oxide, propylene oxide, sodium hydroxide, active fumed silica, Span 20, Span 80, Tween 40, Tween 80, BASF ST2410, BASF ST2437, isopropyl alcohol, concentrated sulfuric acid with a concentration higher than 98%, chloroplatinic acid, and propylene alcohol. Example 1

[0010] Step S1: Preparation of low hydrogen silicone oil 120 g of dimethylcyclosiloxane, 9 g of high hydrogen silicone oil, 2.8 g of hexamethyldisiloxane, and 1.5 g of concentrated sulfuric acid with a mass concentration greater than 98% were added to a reaction vessel, reacted at 60-65° C. for 6 h, then cooled to room temperature, and then sodium hydroxide was added to neutralize the reaction system until it became neutral. The reaction was filtered, and then vacuum distilled below 110° C. to obtain a low hydrogen silicone oil with an active hydrogen mass fraction of approximately 0.06%-0.09%. Step S2: Synthesis of terminal allyl polyoxyethylene polyoxypropylene ether 90 g of propylene alcohol and 10 g of sodium bicarbonate were added to an autoclave, which was protected by nitrogen. The temperature was evacuated and raised to 110° C. 10 g of ethylene oxide and propylene oxide were added while stirring, wherein the mass ratio of ethylene oxide to propylene oxide was 15 / 85. The autoclave was aged until the pressure in the autoclave became negative, and the product was cooled and discharged. The product was neutralized, bleached, filtered, and dehydrated to obtain terminal allyl polyoxyethylene polyoxypropylene ether with a molecular weight of about 400-600. Step S3: Synthesis of polyether-modified silicone Add 40 g of the low-hydrogen silicone oil obtained in step S1, 60 g of the terminal allyl polyoxyethylene polyoxypropylene ether obtained in step S2, 0.2 g of chloroplatinic acid, and 250 g of isopropanol solvent to a reaction kettle, heat to 105° C. under nitrogen protection, react for 8 h, and then distill off the isopropanol solvent to obtain a polyether-modified silicone; Step S4: Preparation of star polymer modified polyether silicone defoamer 18 g of active fumed silica, 82 g of polyether-modified silicone, 6 g of BASF ST2410, 20 g of BASF ST2437 and 12 g of Span-Tween composite emulsifier (containing 2 g of Span 20, 1 g of Span 80, 4 g of Tween 40 and 5 g of Tween 80) were mixed and stirred at 80-90°C for 3 h, cooled and homogenized in a homogenizer for 30 min to prepare star-shaped polymer-modified polyether silicone defoamer 334. Example 2

[0011] Step S1: Preparation of low hydrogen silicone oil 100 g of dimethylcyclosiloxane, 8 g of high hydrogen silicone oil, 2.5 g of hexamethyldisiloxane, and 1 g of concentrated sulfuric acid with a mass concentration greater than 98% were added to a reaction vessel, reacted at 60-65° C. for 4 h, then cooled to room temperature, and then sodium hydroxide was added to neutralize the reaction system until it became neutral. The reaction was filtered, and then vacuum distilled below 110° C. to obtain a low hydrogen silicone oil with an active hydrogen mass fraction of approximately 0.06%-0.09%. Step S2: Synthesis of terminal allyl polyoxyethylene polyoxypropylene ether 80 g of propylene alcohol and 5 g of sodium bicarbonate were added to an autoclave, nitrogen was filled for protection, the temperature was evacuated to 100° C., 8 g of ethylene oxide and propylene oxide were added while stirring, wherein the mass ratio of ethylene oxide to propylene oxide was 15 / 85, and the reaction was carried out until the pressure in the autoclave was negative, and the product was cooled and discharged. The product was neutralized, bleached, filtered, and dehydrated to obtain terminal allyl polyoxyethylene polyoxypropylene ether with a molecular weight of about 400-600; Step S3: Synthesis of polyether-modified silicone Add 30 g of the low-hydrogen silicone oil obtained in step S1, 50 g of the terminal allyl polyoxyethylene polyoxypropylene ether obtained in step S2, 0.1 g of chloroplatinic acid, and 200 g of isopropanol solvent to a reaction kettle, heat to 100° C. under nitrogen protection, react for 6 h, and then distill off the isopropanol solvent to obtain a polyether-modified silicone; Step S4: Preparation of star polymer modified polyether silicone defoamer Star polymer modified polyether silicone defoamer 334 was prepared by mixing 15 g of active fumed silica, 85 g of polyether modified silicone, 3 g of BASF ST2410, 15 g of BASF ST2437 and 10 g of Span-Tween composite emulsifier (containing 2 g of Span 20, 1 g of Span 80, 3 g of Tween 40 and 4 g of Tween 80) at 80-90°C with stirring for 2 h. The mixture was cooled and homogenized in a homogenizer for 20 min. Example 3

[0012] Step S1: Preparation of low hydrogen silicone oil 140 g of dimethylcyclosiloxane, 10 g of high hydrogen silicone oil, 3 g of hexamethyldisiloxane, and 2 g of concentrated sulfuric acid with a mass concentration greater than 98% were added to a reaction vessel, reacted at 60-65° C. for 8 h, then cooled to room temperature, and then sodium hydroxide was added to neutralize the reaction system until it became neutral. The reaction was filtered, and then vacuum distilled below 110° C. to obtain a low hydrogen silicone oil with an active hydrogen mass fraction of approximately 0.06%-0.09%. Step S2: Synthesis of terminal allyl polyoxyethylene polyoxypropylene ether 100 g of propylene alcohol and 20 g of sodium bicarbonate were added to an autoclave, nitrogen was filled for protection, the temperature was evacuated and raised to 120° C., 12 g of ethylene oxide and propylene oxide were added while stirring, wherein the mass ratio of ethylene oxide to propylene oxide was 15 / 85, and the reaction was carried out until the pressure in the autoclave was negative, and the product was cooled and discharged. The product was neutralized, bleached, filtered, and dehydrated to obtain terminal allyl polyoxyethylene polyoxypropylene ether with a molecular weight of about 400-600; Step S3: Synthesis of polyether-modified silicone Add 50 g of the low-hydrogen silicone oil obtained in step S1, 50 g of the terminal allyl polyoxyethylene polyoxypropylene ether obtained in step S2, 0.3 g of chloroplatinic acid, and 300 g of isopropanol solvent to a reaction kettle, heat to 110° C. under nitrogen protection, react for 6 h, and then distill off the isopropanol solvent to obtain a polyether-modified silicone; Step S4: Preparation of star polymer modified polyether silicone defoamer Star polymer modified polyether silicone defoamer 334 was prepared by mixing 20 g of active fumed silica, 80 g of polyether modified silicone, 9 g of BASF ST2410, 22 g of BASF ST2437 and 20 g of Span-Tween composite emulsifier (containing 5 g of Span 20, 3 g of Span 80, 5 g of Tween 40 and 7 g of Tween 80) at 90°C with stirring for 2 h. The mixture was cooled and homogenized in a homogenizer for 30 min.

[0013] Using the star-shaped polymer-modified polyether silicone defoamer 334 prepared in Examples 1-3, the coating has outstanding defoaming and anti-foaming properties during the dispersion and grinding process. In a system with a high-viscosity emulsion content greater than 40%, when the defoamer 334 is used in an amount of less than 0.1%, it meets the use requirements and does not affect the gloss of the paint; the bubble breaking speed during roller coating is less than 3s, and the elimination of tiny bubbles reaches more than 95%. After 30 cross-rolling cycles, the wet film and dry film are in the same state; the defoaming persistence is more than 2 years, and the effect is quite good; the star-shaped polymer-modified polyether silicone defoamer 334 prepared in Examples 1-3 is particularly suitable for systems with high viscosity and higher emulsion content.

[0014] The basic principles, main features and advantages of the present invention are shown and described above. Without departing from the spirit and scope of the present invention, the present invention may also be subject to various changes and improvements, which fall within the scope of the present invention to be protected.

Claims

1. A star polymer modified polyether silicone defoamer, characterized in that Prepared from the following raw materials in parts by weight: 15-20 parts of active fumed silica 80-85 parts of polyether modified silicone BASF ST2410 3-9 parts BASF ST2437 15-22 copies 10-20 parts of Span-Tween composite emulsifier; The formula of Span-Tween composite emulsifier is as follows: Span 20 2-5 servings Span 80 1-3 servings 3-5 parts Tween 40 Tween 80 4-7 parts.

2. The star polymer modified polyether silicone defoamer according to claim 1, characterized in that The specific synthesis process of the polyether-modified silicone is as follows: Step S1: Preparation of low hydrogen silicone oil 100-140 parts by weight of dimethylcyclosiloxane, 8-10 parts by weight of high hydrogen silicone oil, 2.5-3 parts by weight of hexamethyldisiloxane, and 1-2 parts by weight of concentrated sulfuric acid with a concentration higher than 98% are added to a reaction vessel, reacted at 60-65° C. for 4-8 hours, then cooled to room temperature, and then neutralized by adding sodium hydroxide until the reaction system is neutral. The mixture is filtered and then distilled under reduced pressure at below 110° C. to obtain low hydrogen silicone oil with an active hydrogen mass fraction of 0.06%-0.09%. Step S2: Synthesis of terminal allyl polyoxyethylene polyoxypropylene ether 80-100 parts by weight of propylene alcohol and 5-20 parts by weight of sodium bicarbonate are added to an autoclave, nitrogen is filled for protection, the temperature is evacuated and raised to 100-120° C., 8-12 parts by weight of ethylene oxide and propylene oxide are added while stirring, wherein the mass ratio of ethylene oxide to propylene oxide is 15 / 85, and the reaction is carried out until the pressure in the autoclave becomes negative pressure, and the product is cooled and discharged. The product is neutralized, bleached, filtered, and dehydrated to obtain terminal allyl polyoxyethylene polyoxypropylene ether with a molecular weight of 400-600; Step S3: Synthesis of polyether-modified silicone Add 30-50 parts by weight of the low-hydrogen silicone oil obtained in step S1, 50-70 parts by weight of the terminal allyl polyoxyethylene polyoxypropylene ether obtained in step S2, 0.1-0.3 parts by weight of chloroplatinic acid, and 200-300 parts by weight of isopropanol solvent into a reaction kettle, heat to 100-110° C. under nitrogen protection, react for 6-10 hours, and then distill off the isopropanol solvent to obtain a polyether-modified silicone.

3. The star polymer modified polyether silicone defoamer according to claim 1 or 2, characterized in that The star-shaped polymer-modified polyether silicone defoamer 334 is prepared by mixing 15-20 parts by weight of active fumed silica, 80-85 parts by weight of polyether-modified silicone, 3-9 parts by weight of BASF ST2410, 15-22 parts by weight of BASF ST2437, and 10-20 parts by weight of a Span-Tween composite emulsifier at 80-90° C. and stirring for 2-4 hours, cooling, and homogenizing in a homogenizer for 20-40 minutes to obtain the star-shaped polymer-modified polyether silicone defoamer 334.