Fatty alcohol emulsion defoaming agent

Abstract

The invention provides a fatty alcohol emulsion defoaming agent which is characterized in that fatty alcohol and paraffin are used as defoaming active matters, the paraffin is divided into a paraffin part 1 and a paraffin part 2, and carbonic acid distribution and alkane component composition of the paraffin part 1 and the paraffin part 2 are respectively limited; the carbon number distribution of the paraffin 1 is C20-C40, and the content of straight-chain paraffin is 70-90%; the carbon number distribution of the paraffin 2 is C40-C60, and the content of isoparaffin is 70-90%; the early-stage crystallization speed of the paraffin 1 is high, so that the defoaming performance of the fatty alcohol emulsion is improved; the crystallization speed of the paraffin 2 in the later stage is low, the foam inhibition performance in the later stage is improved, the paraffin 1 and the paraffin 2 are synergistically compounded, and the temperature application range of the fatty alcohol emulsion product is widened; in the emulsion preparation process, proper emulsifiers are selected to emulsify fatty alcohol, paraffin 1 and paraffin 2 respectively to form respective emulsions, and finally the emulsions are mixed, so that the stability of the final emulsion is improved.

Description

Technical Field

[0001] The invention relates to a fatty alcohol emulsion defoamer. The defoamer is a fine chemical additive. Therefore, the invention belongs to the technical field of fine chemicals. Background Art

[0002] The papermaking process is roughly divided into three parts: pulp preparation, papermaking, and rewinding. Among them, the processes in the papermaking section need to remove the gas in the white water. At the same time, the white water mainly contains fine fibers, fillers, coatings and dissolved wood components, as well as added sizing agents, wet strength agents, preservatives, etc. At present, white water is generally a closed cycle, which is easy to produce bubbles. The existence of these bubbles has a great impact on paper, resulting in poor sizing, spots, light spots and small holes on the paper surface, and even causing paper breaks. It is easy to reduce the operating efficiency of the pump and increase energy consumption.

[0003] Fatty alcohol emulsion defoamer is a commonly used defoamer in papermaking white water. In the early stage of the development of fatty alcohol defoamer, the defoaming active ingredient was mainly fatty alcohol. For example, CN100358607C used higher fatty alcohol, higher fatty alcohol polyether, nitrogen-containing polyether, and fatty acid ester as the main active ingredients to prepare emulsion defoamer; CN101003008A used higher fatty alcohol and silicone as active ingredients to prepare emulsion defoamer; higher fatty alcohol has good defoaming and degassing performance, but the price of raw materials is high, which is one of the factors restricting its promotion and application. In order to reduce the raw material cost of fatty alcohol emulsion products, In the present invention, those skilled in the art introduce substances such as oil, paraffin and the like as defoaming active substances to reduce the cost of raw materials. The introduction of paraffin and oil reduces the material cost, but the defoaming and defoaming performance will be affected. Therefore, many technologies are devoted to improving the defoaming and defoaming performance. For example, CN100547158C is composed of fatty alcohol, modified polyether, silicone polyether and natural oil, and solves the problem of poor defoaming and degassing performance of defoaming agent under high temperature conditions through compounding and synergistic effect; CN100549295C is composed of an organic hydrocarbon mixture containing hydrophobic particles, fatty alcohol, fatty alcohol polyether, modified polyether, Silicone polyether composition improves the defoaming and defoaming performance of the defoamer through the synergistic effect of the composite components; on the other hand, the introduction of other active ingredients such as paraffin and oils is different from the structure of fatty alcohol active ingredients, resulting in an unstable emulsion system, and the emulsion finally prepared is easy to stratify or cream. Therefore, how to improve the stability is also a problem that fatty alcohol emulsions need to solve. For example, in CN102600647A, fatty alcohol, mineral oil, paraffin, and fatty acid esters are used as active ingredients, fatty acid esters are introduced into the defoamer emulsion system, and anionic surfactants are added in the later stage of the emulsification process. Allow anionic surfactants to adsorb on the surface of fatty alcohols, and make fatty alcohol emulsions more stable through the effect of ion repulsion; CN103830937A also uses fatty alcohols, mineral oils, paraffin, and fatty acid esters as active substances, and uses a two-step emulsification method to stabilize natural fatty alcohol emulsions, which uses nonionic emulsifiers to emulsify and encapsulate natural fatty alcohols twice, and disperses natural fatty alcohols twice through dispersants to prevent the aggregation of particles in the emulsion, and stabilizes the natural fatty alcohol emulsion through secondary high-speed shearing. The obtained natural fatty alcohol emulsion maintains good stability at a wide storage temperature. CN103628353A uses fatty alcohols, fatty acid esters, mineral oils, and paraffin as active substances, and uses a high-speed disperser to strongly disperse the fatty alcohol emulsion so that the fatty alcohol particles are evenly dispersed in the water phase, and a good dispersion effect can be achieved through the synergistic effect of a polymer polyacrylate dispersant and a polymer polyacrylic acid thickener. The high molecular weight polyacrylic acid salt dispersant is adsorbed on the emulsified material, and the emulsified material is evenly dispersed through the high-intensity electric charge, and the high molecular weight polyacrylic acid thickener is added to play a wrapping role, thereby achieving the purpose of stability.In CN107137959A, fatty alcohol, paraffin and grease are used as active substances, and fatty alcohol, paraffin and grease are prepared into emulsions respectively using non-ionic surfactants, thickeners and water, and then the three emulsions are mixed with anionic surfactants at room temperature to obtain a non-silicon emulsion defoamer. The preparation method is simple in process, the prepared emulsion is more stable, and the defoaming and defoaming performance is improved. Summary of the invention

[0004] The invention uses fatty alcohol and paraffin as defoaming active substances, wherein the paraffin is divided into two parts, paraffin 1 and paraffin 2, and the carbonic acid distribution and alkane component composition of paraffin 1 and paraffin 2 are respectively limited; the carbon number distribution of paraffin 1 is C20-C40, wherein the content of straight-chain alkanes is 70-90%; the carbon number distribution of paraffin 2 is C40-C60, wherein the content of isomeric alkanes is 70-90%; the crystallization speed of paraffin 1 is fast in the early stage, and the defoaming performance of the fatty alcohol emulsion is improved; the crystallization speed of paraffin 2 is slow in the later stage, and the defoaming performance in the later stage is improved; paraffin 1 and paraffin 2 are synergistically compounded, and the applicable temperature range of the fatty alcohol emulsion product is improved; in the process of preparing the emulsion, a suitable emulsifier is selected to emulsify the fatty alcohol, paraffin 1 and paraffin 2 respectively to form respective emulsions, and finally the emulsions are mixed to improve the stability of the final emulsion. Technical Solution

[0005] The fatty alcohol emulsion defoamer described in the present invention is composed of the following components: A. Fatty alcohol Fatty alcohols are monohydric to trihydric alcohols of C12-C30, including synthetic fatty alcohols and natural fatty alcohols. Synthetic fatty alcohols can be obtained by oxidation of alkyl aluminum by the Ziegler method, or by carbonyl synthesis; natural fatty alcohols can be obtained by extraction from oils and fats. Specifically, the fatty alcohols include fatty alcohols containing a single carbon atom, such as C12 alcohol, C14 alcohol, C16 alcohol, C18 alcohol, C20 alcohol, C22 alcohol, C24 alcohol, C26 alcohol, C28 alcohol, C30 alcohol; and mixed fatty alcohols containing different numbers of carbon atoms, such as C12-18 mixed alcohol, C16-18 mixed alcohol, C16-22 mixed alcohol, one or more of which are selected, and the amount of fatty alcohol used accounts for 15-25% of the total mass of the emulsion; B. Paraffin Paraffin is a hydrocarbon extracted from petroleum, shale oil or other asphalt mineral oils. Paraffin is divided into two parts: paraffin 1 and paraffin 2. Paraffin 1: The carbon number distribution is C20-C30, and the content of straight-chain alkanes is 70-90%; the amount of paraffin 1 accounts for 2-8% of the total mass of the emulsion; Paraffin 2: The carbon number distribution is C40-C60, and the content of isoparaffins is 70-90%; the amount of paraffin 2 accounts for 2-8% of the total mass of the emulsion; C. Nonionic surfactant Nonionic surfactants are divided into three categories: The structural formula of nonionic surfactant C1 is: R1O(EO) m H, wherein R1 is a C18-28 alkyl group, m is an integer of 25-60, and the amount used is 0.5-5% of the total mass of the emulsion; The structural formula of nonionic surfactant C2 is: R2O(EO) n H, wherein R2 is a C8-18 alkyl group, m is an integer of 10-20, and the amount used is 0.5-5% of the total mass of the emulsion; The structural formula of nonionic surfactant C3 is: R3O(EO) z H, wherein R3 is a C18-28 alkyl group, z is an integer of 10-20, and the amount used is 0.5-5% of the total mass of the emulsion; D. Thickener The thickener is selected from one or more of xanthan gum, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, polyacrylic acid, polyacrylamide and polyacrylate, preferably polyacrylate. The amount of the thickener is 1-3% of the total mass of the emulsion. The thickener is divided into three parts, each accounting for one third of the total mass of the thickener; E. Anionic surfactant The anionic surfactant is selected from one or more of alkyl sulfonates, alkyl diphenyl ether disulfonates, alkylphenol polyoxyethylene ether phosphate salts, and fatty alcohol polyoxyethylene ether sulfates, and is specifically selected from one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl phosphate, and sodium dodecyl diphenyl ether disulfonate; the amount of the anionic surfactant is 0.03-0.1% of the total mass of the defoamer F. Water The amount of water used accounts for 60-75% of the total emulsion; the water is used in three parts, each accounting for one third of the total water mass.

[0006] The preparation method of the fatty alcohol emulsion defoamer is: (1) Preparation of fatty alcohol emulsion: Mix fatty alcohol and nonionic surfactant C1, heat to 70-90°C and stir evenly, slowly add 70-90°C water to the mixture, further emulsify through high-speed shearing equipment, cool to room temperature, add thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: paraffin and nonionic surfactant C2 are mixed, heated to 70-80°C and stirred evenly, 70-80°C water is slowly added to the mixture, further emulsified by high-speed shearing equipment, cooled to room temperature, and thickener is added and stirred evenly; (3) Preparation of paraffin 2 emulsion: paraffin and nonionic surfactant C3 are mixed, heated to 80-90°C and stirred evenly, 80-90°C water is slowly added to the mixture, further emulsified by high-speed shearing equipment, cooled to room temperature, and thickener is added and stirred evenly; (4) The fatty alcohol emulsion, the paraffin 1 emulsion, the paraffin 2 emulsion and the anionic surfactant are uniformly mixed at room temperature to obtain the defoaming agent of the present invention. DETAILED DESCRIPTION Example 1

[0008] (1) Preparation of fatty alcohol emulsion: 15 g of C16-22 mixed alcohol, 2 g of nonionic surfactant C 18 H 37 O(EO) 25 H, heat to 70°C and stir evenly, slowly add 20g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.6g of polyacrylate thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 8 g paraffin 1 (carbon number distribution C20-C30, straight chain alkane content 70.2%), 3 g nonionic surfactant C8H 17 O(EO) 20 H mixture, heat to 80°C and stir evenly, slowly add 20g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.6g of polyacrylate thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 6 g paraffin 2 (carbon number distribution C40-C51, isoparaffin content 85.2%), 4 g nonionic surfactant C 18 H 37 O(EO) 25 H mixture, heat to 80°C and stir evenly, slowly add 20g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.7g of polyacrylate thickener and stir evenly; (4) The fatty alcohol emulsion, the paraffin 1 emulsion, the paraffin 2 emulsion and 0.1 g of anionic surfactant sodium dodecyl sulfate are uniformly mixed at room temperature to obtain the defoaming agent of the present invention. Example 2

[0009] (1) Preparation of fatty alcohol emulsion: 18 g of C18 alcohol, 1 g of nonionic surfactant C 20 H 41 O(EO) 40H, heat to 80°C and stir evenly, slowly add 21.65g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 1g of the xanthan gum and guar gum mixture and stir evenly; (2) Preparation of paraffin 1 emulsion: 2 g paraffin 1 (carbon number distribution C22-C30, straight chain alkane content 72.4%), 2 g nonionic surfactant C 10 H 21 O(EO) 16 H mixture, heat to 70°C and stir evenly, slowly add 21.65g of 70°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 1g of xanthan gum and guar gum mixture and stir evenly; (3) Preparation of paraffin 2 emulsion: 8 g paraffin 2 (carbon number distribution C42-C55, isoparaffin content 75.2%), 1 g nonionic surfactant C 20 H 41 O(EO) 40 H mixture, heat to 90°C and stir evenly, slowly add 21.65g of 90°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 1g of xanthan gum and guar gum mixture and stir evenly; (4) The fatty alcohol emulsion, the paraffin 1 emulsion, the paraffin 2 emulsion and 0.05 g of anionic surfactant sodium dodecylbenzene sulfonate are uniformly mixed at room temperature to obtain the defoaming agent of the present invention. Example 3

[0010] (1) Preparation of fatty alcohol emulsion: 20 g of a mixture of C20 alcohol, C22 alcohol and C24 alcohol, 0.5 g of a nonionic surfactant C 25 H 51 O(EO) 60 H, heat to 90°C and stir evenly, slowly add 21.82g of 90°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of hydroxyethyl cellulose and methyl cellulose mixture and stir evenly; (2) Preparation of paraffin 1 emulsion: 4 g paraffin 1 (carbon number distribution C23-C30, straight chain alkane content 83.1%), 5 g nonionic surfactant C 14 H 29 O(EO) 10 H mixture, heat to 75°C and stir evenly, slowly add 21.82g of 75°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of a mixture of hydroxyethyl cellulose and methyl cellulose and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C40-C60, isoparaffin content 70.5%), 2 g nonionic surfactant C 18 H 37 O(EO) 25 H mixture, heat to 85°C and stir evenly, slowly add 21.83g of 85°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.34g of a mixture of hydroxyethyl cellulose and methyl cellulose and stir evenly; (4) The fatty alcohol emulsion, the paraffin 1 emulsion, the paraffin 2 emulsion and 0.03 g of anionic surfactant sodium dodecyl phosphate are uniformly mixed at room temperature to obtain the defoaming agent of the present invention. Example 4

[0011] (1) Preparation of fatty alcohol emulsion: 25 g of C16-18 mixed alcohol, 5 g of nonionic surfactant C 28 H 57 O(EO) 30 H, heat to 70°C and stir evenly, slowly add 20.97g of 70°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.66g of polyacrylic acid thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 2 g paraffin 1 (carbon number distribution C21-C30, straight chain alkane content 89.9%), 0.5 g nonionic surfactant C 12 H 25 O(EO) 14 H mixture, heat to 75°C and stir evenly, slowly add 20.97g 75°C water to the mixture, further emulsify through high-speed shearing equipment, cool to room temperature, add 0.67g polyacrylic acid thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C45-C59, isoparaffin content 79.8%), 0.5 g nonionic surfactant C 28 H 57 O(EO) 30 H mixture, heat to 85°C and stir evenly, slowly add 20.98g of 85°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.67g of polyacrylic acid thickener and stir evenly; (4) The fatty alcohol emulsion, the paraffin 1 emulsion, the paraffin 2 emulsion and 0.08 g of anionic surfactant sodium dodecyl diphenyl ether disulfonate are mixed uniformly at room temperature to obtain the defoaming agent of the present invention. Example 5

[0012] (1) Preparation of fatty alcohol emulsion: 16 g of C16-22 mixed alcohol, 1 g of nonionic surfactant C 21 H 43 O(EO) 50 H, heat to 85°C and stir evenly, slowly add 25g of 85°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of polyacrylamide thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 3 g paraffin 1 (carbon number distribution C20-C29, straight chain alkane content 84.9%), 0.5 g nonionic surfactant C 18 H 37 O(EO) 11 H mixture, heat to 80°C and stir evenly, slowly add 25g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of polyacrylamide thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C47-C60, isoparaffin content 89.8%), 1.45 g nonionic surfactant C 21 H 43 O(EO) 50 H mixture, heat to 90°C and stir evenly, slowly add 25g of 90°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.34g of polyacrylamide thickener and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion, and 0.05 g of a mixture of sodium dodecyl sulfate and sodium dodecylbenzene sulfonate are uniformly mixed at room temperature to obtain the defoaming agent of the present invention. Example 6

[0013] (1) Preparation of fatty alcohol emulsion: 17 g of a mixture of C12 fatty alcohol and C30 fatty alcohol, 0.97 g of a nonionic surfactant C 26 H 53 O(EO) 32 H, heat to 80°C and stir evenly, slowly add 23.3g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of carboxymethyl cellulose thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 2.5 g paraffin 1 (carbon number distribution C20-C29, straight chain alkane content 88.2%), 1.5 g nonionic surfactant C9H 19 O(EO) 18H mixture, heat to 75°C and stir evenly, slowly add 23.3g of 75°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of carboxymethyl cellulose thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C43-C57, isoparaffin content 83.2%), 5 g nonionic surfactant C 26 H 53 O(EO) 32 H mixture, heat to 85°C and stir evenly, slowly add 23.3g of 85°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.34g of carboxymethyl cellulose thickener and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion and 0.03 g of sodium dodecylbenzene sulfonate are uniformly mixed at room temperature to obtain the defoaming agent of the present invention.

[0014] Comparative Example 1 (1) Preparation of fatty alcohol emulsion: 15 g of C16-22 mixed alcohol, 2 g of nonionic surfactant C 18 H 37 O(EO) 25 H, heat to 70°C and stir evenly, slowly add 20g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.6g of polyacrylate thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 8 g paraffin 1 (carbon number distribution C20-C30, straight chain alkane content 55.6%), 3 g nonionic surfactant C8H 17 O(EO) 20 H mixture, heat to 80°C and stir evenly, slowly add 20g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.6g of polyacrylate thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 6 g paraffin 2 (carbon number distribution C40-C51, isoparaffin content 85.2%), 4 g nonionic surfactant C 18 H 37 O(EO) 25 H mixture, heat to 80°C and stir evenly, slowly add 20g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.7g of polyacrylate thickener and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion and 0.1 g of anionic surfactant sodium dodecyl sulfate are mixed uniformly at room temperature to obtain the final defoaming agent. Comparative Example 2

[0015] (1) Preparation of fatty alcohol emulsion: 18 g of C18 alcohol, 1 g of nonionic surfactant C 20 H 41 O(EO) 40 H, heat to 80°C and stir evenly, slowly add 21.65g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 1g of the xanthan gum and guar gum mixture and stir evenly; (2) Preparation of paraffin 1 emulsion: 2 g paraffin 1 (carbon number distribution C30-C41, straight chain alkane content 72.4%), 2 g nonionic surfactant C 10 H 21 O(EO) 16 H mixture, heat to 70°C and stir evenly, slowly add 21.65g of 70°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 1g of xanthan gum and guar gum mixture and stir evenly; (3) Preparation of paraffin 2 emulsion: 8 g paraffin 2 (carbon number distribution C42-C55, isoparaffin content 75.2%), 1 g nonionic surfactant C 20 H 41 O(EO) 40 H mixture, heat to 90°C and stir evenly, slowly add 21.65g of 90°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 1g of xanthan gum and guar gum mixture and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion and 0.05 g of anionic surfactant sodium dodecylbenzene sulfonate are mixed uniformly at room temperature to obtain the final defoaming agent. Comparative Example 3

[0016] (1) Preparation of fatty alcohol emulsion: 20 g of a mixture of C20 alcohol, C22 alcohol and C24 alcohol, 0.5 g of a nonionic surfactant C 25 H 51 O(EO) 60 H, heat to 90°C and stir evenly, slowly add 21.82g of 90°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of hydroxyethyl cellulose and methyl cellulose mixture and stir evenly; (2) Preparation of paraffin 1 emulsion: 4 g paraffin 1 (carbon number distribution C23-C30, straight chain alkane content 83.1%), 5 g nonionic surfactant C 14 H 29 O(EO) 10H mixture, heat to 75°C and stir evenly, slowly add 21.82g of 75°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of a mixture of hydroxyethyl cellulose and methyl cellulose and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C40-C60, isoparaffin content 64.7%), 2 g nonionic surfactant C 18 H 37 O(EO) 25 H mixture, heat to 85°C and stir evenly, slowly add 21.83g of 85°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.34g of a mixture of hydroxyethyl cellulose and methyl cellulose and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion and 0.03 g of anionic surfactant sodium dodecyl phosphate are mixed uniformly at room temperature to obtain the final defoaming agent. Comparative Example 4

[0017] (1) Preparation of fatty alcohol emulsion: 25 g of C16-18 mixed alcohol, 5 g of nonionic surfactant C 28 H 57 O(EO) 30 H, heat to 70°C and stir evenly, slowly add 20.97g of 70°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.66g of polyacrylic acid thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 2 g paraffin 1 (carbon number distribution C21-C30, straight chain alkane content 89.9%), 0.5 g nonionic surfactant C 12 H 25 O(EO) 14 H mixture, heat to 75°C and stir evenly, slowly add 20.97g 75°C water to the mixture, further emulsify through high-speed shearing equipment, cool to room temperature, add 0.67g polyacrylic acid thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C20-C35, isoparaffin content 79.8%), 0.5 g nonionic surfactant C 28 H 57 O(EO) 30 H mixture, heat to 85°C and stir evenly, slowly add 20.98g of 85°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.67g of polyacrylic acid thickener and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion and 0.08 g of anionic surfactant sodium dodecyl diphenyl ether disulfonate are mixed uniformly at room temperature to obtain the final defoaming agent. Comparative Example 5

[0018] 16g of C16-22 mixed alcohol, 3g of paraffin 1 (carbon number distribution C20-C29, straight-chain alkane content 84.9%), 2g of paraffin 2 (carbon number distribution C47-C60, isomeric alkane content 89.8%), 1g of nonionic surfactant C 21 H 43 O(EO) 50 H, 0.5g nonionic surfactant C 18 H 37 O(EO) 11 H, 1.45g nonionic surfactant C 21 H 43 O(EO) 50 H is heated to 80°C and stirred evenly, 75g of 85°C water is slowly added to the above mixture, further emulsified by high-speed shearing equipment, cooled to room temperature, 0.1g of polyacrylamide thickener is added and stirred evenly; finally, 0.05g of a mixture of sodium dodecyl sulfate and sodium dodecylbenzene sulfonate is added and mixed evenly at room temperature to obtain the final defoaming agent. Comparative Example 6

[0019] (1) Preparation of fatty alcohol emulsion: 17 g of a mixture of C12 fatty alcohol and C30 fatty alcohol, 0.97 g of a nonionic surfactant C 26 H 53 O(EO) 32 H, heat to 80°C and stir evenly, slowly add 23.3g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of carboxymethyl cellulose thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 2.5 g paraffin 1 (carbon number distribution C20-C29, straight chain alkane content 88.2%), 1.5 g nonionic surfactant C9H 19 O(EO) 18 H mixture, heat to 75°C and stir evenly, slowly add 23.3g of 75°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.33g of carboxymethyl cellulose thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 2 g paraffin 2 (carbon number distribution C43-C57, isoparaffin content 83.2%), 5.03 g nonionic surfactant C 26 H 53 O(EO) 32H mixture, heat to 85°C and stir evenly, slowly add 23.3g of 85°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.34g of carboxymethyl cellulose thickener and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, and paraffin 2 emulsion are mixed uniformly at room temperature to obtain the final defoaming agent. Comparative Example 7

[0020] (1) Preparation of fatty alcohol emulsion: 15 g of C16-22 mixed alcohol, 2 g of nonionic surfactant C 18 H 37 O(EO) 25 H, heat to 70°C and stir evenly, slowly add 20g of 80°C water to the above mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.6g of polyacrylate thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: 8g white oil, 3g nonionic surfactant C8H 17 O(EO) 20 H mixture, heat to 80°C and stir evenly, slowly add 20g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.6g of polyacrylate thickener and stir evenly; (3) Preparation of paraffin 2 emulsion: 6 g white oil, 4 g nonionic surfactant C 18 H 37 O(EO) 25 H mixture, heat to 80°C and stir evenly, slowly add 20g of 80°C water to the mixture, further emulsify through a high-speed shearing device, cool to room temperature, add 0.7g of polyacrylate thickener and stir evenly; (4) The fatty alcohol emulsion, paraffin 1 emulsion, paraffin 2 emulsion and 0.1 g of anionic surfactant sodium dodecyl sulfate are mixed uniformly at room temperature to obtain the final defoaming agent.

[0021] Performance Testing 1. Emulsion stability test

[0022] The emulsions prepared in the above examples and comparative examples were placed at 5°C, 25°C, and 40°C for 6-month viscosity tracking tests. The specific viscosity test method uses a NDJ-8 digital display viscometer, 2# rotor, and 6rpm conditions for testing. The specific situation is shown in Table 1 below (viscosity unit mPa.s, "-" means the emulsion is a paste and cannot flow): Table 1 Changes in emulsion viscosity at different storage temperatures

[0023] From the viscosity tracking data, it can be seen that the viscosity of the defoamer prepared by the present invention changes slightly when stored at 5°C, 25°C and 40°C for 6 months, showing good storage stability. The viscosity of the fatty alcohol emulsions prepared in Comparative Examples 1-6 increases to varying degrees after 6 months.

[0024] 2. Test method for anti-foaming performance: The performance of the defoaming agent is determined by the circulating bubbling method. Add 600 ml of white water into the circulating bubbling equipment and heat it to the required temperature. Turn on the flow pump and circulate at a flow rate of 8 / L min until the foam volume reaches 300 ml. Add 6 ul of defoaming agent and record the change of foam volume over time. Within the same time, the smaller the volume, the better the defoaming and antifoaming performance; the longer the time for the foam to reach 300 ml again, the better the antifoaming performance.

[0025]

Claims

1. A fatty alcohol emulsion defoamer, characterized in that: It is composed of the following components: A. Fatty alcohol The fatty alcohol is a monohydric to trihydric alcohol of C12-C30, including synthetic fatty alcohol and natural fatty alcohol. The synthetic fatty alcohol can be obtained by oxidation of alkyl aluminum by Ziegler method or by carbonyl synthesis method; the natural fatty alcohol can be obtained by extraction from oils and fats. Specifically, the fatty alcohol includes fatty alcohol containing a single carbon atom, such as C12 alcohol, C14 alcohol, C16 alcohol, C18 alcohol, C20 alcohol, C22 alcohol, C24 alcohol, C26 alcohol, C28 alcohol, C30 alcohol; and mixed fatty alcohols containing different numbers of carbon atoms, such as C12-18 mixed alcohol, C16-18 mixed alcohol, C16-22 mixed alcohol, one or more of which are selected, and the amount of fatty alcohol accounts for 15-25% of the total mass of the emulsion; B. Paraffin Paraffin is a hydrocarbon extracted from petroleum, shale oil or other asphalt mineral oils. Paraffin is divided into two parts: paraffin 1 and paraffin 2. Paraffin 1: The carbon number distribution is C20-C30, and the content of straight-chain alkanes is 70-90%; the amount of paraffin 1 accounts for 2-8% of the total mass of the emulsion; Paraffin 2: The carbon number distribution is C40-C60, and the content of isoparaffins is 70-90%; the amount of paraffin 2 accounts for 2-8% of the total mass of the emulsion; C. Nonionic surfactant Nonionic surfactants are divided into three categories: The structural formula of nonionic surfactant C1 is: R1O(EO) m H, wherein R1 is a C18-28 alkyl group, m is an integer of 25-60, and the amount used is 0.5-5% of the total mass of the emulsion; The structural formula of nonionic surfactant C2 is: R2O(EO) n H, wherein R2 is a C8-18 alkyl group, m is an integer of 10-20, and the amount used is 0.5-5% of the total mass of the emulsion; The structural formula of nonionic surfactant C3 is: R3O(EO) z H, wherein R3 is a C18-28 alkyl group, z is an integer of 10-20, and the amount used is 0.5-5% of the total mass of the emulsion; D. Thickener The thickener is selected from one or more of xanthan gum, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, polyacrylic acid, polyacrylamide and polyacrylate, and the amount of the thickener accounts for 1-3% of the total mass of the emulsion. The thickener is divided into three parts, each accounting for one third of the total mass of the thickener; E. Anionic surfactant The anionic surfactant is selected from one or more of alkyl sulfonates, alkyl diphenyl ether disulfonates, alkylphenol polyoxyethylene ether phosphates, and fatty alcohol polyoxyethylene ether sulfates. The amount of the anionic surfactant accounts for 0.03 to 0.1% of the total mass of the defoamer. F. Water The amount of water used accounts for 60-75% of the total emulsion; the water is used in three parts, each accounting for one third of the total water mass.

2. A fatty alcohol emulsion defoamer according to claim 1, wherein the preparation method thereof is: (1) Preparation of fatty alcohol emulsion: Mix fatty alcohol and nonionic surfactant C1, heat to 70-90°C and stir evenly, slowly add 70-90°C water to the mixture, further emulsify through high-speed shearing equipment, cool to room temperature, add thickener and stir evenly; (2) Preparation of paraffin 1 emulsion: paraffin and nonionic surfactant C2 are mixed, heated to 70-80°C and stirred evenly, 70-80°C water is slowly added to the mixture, further emulsified by high-speed shearing equipment, cooled to room temperature, and thickener is added and stirred evenly; (3) Preparation of paraffin 2 emulsion: paraffin and nonionic surfactant C3 are mixed, heated to 80-90°C and stirred evenly, 80-90°C water is slowly added to the mixture, further emulsified by high-speed shearing equipment, cooled to room temperature, and thickener is added and stirred evenly; (4) The fatty alcohol emulsion, the paraffin 1 emulsion, the paraffin 2 emulsion and the anionic surfactant are uniformly mixed at room temperature to obtain the defoaming agent of the present invention.

3. A fatty alcohol emulsion defoamer according to claim 1, characterized in that, The thickener is polyacrylate.

4. A fatty alcohol emulsion defoamer according to claim 1, characterized in that, The anionic surfactant is selected from one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl phosphate, and sodium dodecyl diphenyl ether disulfonate.

Images