Preparation method of polyether ester defoaming agent

Abstract

The invention provides a polyether ester defoaming agent and a preparation method thereof. Firstly, glycidyl ether and short-chain alcohol react to prepare polyether, and finally, fatty acid is used for blocking to prepare polyether ester 1 #; glycidyl ether, polyethylene glycol and / or polypropylene glycol react to prepare polyether, and finally fatty acid is used for blocking to prepare polyether ester 2 #; glycidol ether, short-chain alcohol, polyethylene glycol and / or polypropylene glycol react to prepare polyether, unsaturated fatty acid continues to be used for blocking to obtain polyether ester, the polyether ester and hydrogen-containing silicone oil continue to react to obtain branched silicon polyether 3 #, and the two polyether esters and the branched silicon polyether are compounded and cooperated to form the final polyether ester defoaming agent. The polyether ester 1 #, the polyether ester 2 # and the branched silicon polyether 3 # all have hyperbranched structures, the polyether ester 1 # improves the dispersing performance and the instant defoaming performance of the defoaming agent, the polyether ester 2 # and the branched silicon polyether 3 # improve the foam inhibition performance of the defoaming agent, and the three substances are compounded to form the stable polyether ester defoaming agent with both defoaming and foam inhibition performance.

Description

Technical Field

[0001] The invention belongs to the technical field of defoamers, and particularly relates to a method for preparing a polyether ester defoamer. Background Art

[0002] Defoamers have a highly effective defoaming effect on foaming systems. There are many types of defoamers. After years of development, a defoamer system mainly composed of mineral oils, fatty alcohols, polyethers, silicones, and modified silicones has been formed. The defoaming and antifoaming performance of silicone defoamers is particularly outstanding, but the problems of silicon spots and silicone grease precipitation easily limit their promotion and application; the heat resistance and acid and alkali resistance of fatty alcohol defoamers are poor; the environmental protection performance of mineral oil defoamers needs to be further improved; polyether ester defoamers are a kind of high-efficiency defoamers developed on the basis of polyether defoamers. They have the characteristics of high temperature resistance, acid and alkali resistance, and good stability of polyether defoamers. Moreover, after esterification, the hydrogen bonds between water molecules and polyoxyethylene chains are weakened, the lipophilicity is increased, and the surface tension is reduced, thereby improving its defoaming and antifoaming performance. It can be seen that polyether ester defoamers take into account the advantages and characteristics of polyethers, and further improve the defoaming and antifoaming performance of polyethers.

[0003] CN106975247A discloses a novel polyetherester defoamer and its preparation method, wherein a higher fatty alcohol with a carbon chain length greater than 18 is used as an initiator to prepare a polyether, and then a higher fatty acid is used for esterification. CN11040149A discloses a method for preparing a polyetherester papermaking defoamer, wherein a polyol is reacted with ethylene oxide and propylene oxide, and finally a fatty acid is used for end-capping to prepare a polyetherester defoamer; CN117143328A uses a high-carbon fatty alcohol polyoxyethylene polyoxypropylene ether to react with a fatty acid under the action of a catalyst to prepare a high-carbon alcohol polyetherester; CN117258358A discloses a polyetherester defoamer, wherein a monofunctional polyol is used as an initiator, and then a polyether is obtained by reacting with ethylene oxide and propylene oxide, and finally a polyether is obtained by end-capping with a fatty acid. The above patents use alcohols as initiators, graft ethylene oxide and propylene oxide, and finally use fatty acid end-capping to prepare polyether ester defoamers. The defoaming and anti-foaming properties still need to be improved; CN112961535A discloses a composite defoamer for water-based environmentally friendly coatings, which uses cardanol, itaconic acid, and polyethylene glycol to react under the action of an acidic catalyst to prepare itaconic acid cardanol polyether ester. As the environmental performance of the defoamer is improved, the defoaming performance is still a problem;

[0004] CN112742073A discloses a modified tung linoleic acid polyether ester coating defoamer, in which tung linoleic acid, terminal hydroxyl polyether and fluoroalkyl hydrogenated silicone oil are reacted to prepare the polyether defoamer; CN114949938A discloses an aqueous mineral oil defoamer and a preparation method thereof, in which polyether modified silicone oil and lauric acid are reacted under the action of an acidic catalyst to obtain a polyether ester; the above patents introduce a silicone oil structure into the polyether ester structure, thereby improving the defoaming and anti-foaming performance, but may cause compatibility problems of the defoamer. Summary of the invention

[0005] The invention provides a polyether ester defoamer and a preparation method thereof. Firstly, polyether is prepared by reacting glycidyl ether and short-chain alcohol, and finally a fatty acid is used to end-cap to prepare polyether ester 1#; polyether is prepared by reacting glycidyl ether, polyethylene glycol and / or polypropylene glycol, and finally a fatty acid is used to end-cap to prepare polyether ester 2#; glycidyl ether, short-chain alcohol, polyethylene glycol and / or polypropylene glycol are reacted to prepare polyether, and unsaturated fatty acid is used to end-cap to obtain polyether ester; the polyether ester is reacted with hydrogen-containing The silicone oil continues to react to obtain branched silicon polyether 3#, and the two polyether esters are compounded with the branched silicon polyether to form the final polyether ester defoamer; polyether ester 1#, polyether ester 2# and branched silicon polyether 3# all have hyperbranched structures, among which polyether ester 1# improves the dispersibility and instantaneous defoaming performance of the defoamer, polyether ester 2# and branched silicon polyether 3# improve the antifoaming performance of the defoamer, and the three substances are compounded to form a stable polyether ester defoamer with both defoaming and antifoaming performance.

[0006] The polyether ester defoamer of the present invention is composed of the following components:

[0007] Polyether ester 1#: polyether 1# is prepared by ring-opening reaction of glycidyl ether and short-chain alcohol, and finally polyether ester 1# is prepared by esterification reaction with fatty acid; the amount of polyether ester 1# accounts for 5-20% of the total mass of polyether ester defoamer;

[0008] Polyether ester 2#: Polyether 2# is prepared by ring-opening reaction of glycidyl ether and long-chain alcohol, and finally polyether ester 2# is prepared by esterification reaction with fatty acid; the amount of polyether ester 2# accounts for 30-60% of the total mass of polyether ester defoamer;

[0009] Branched silicon polyether 3#: prepare polyether 3# by ring-opening reaction of glycidyl ether and polypropylene glycol, further esterify with unsaturated fatty acid to obtain polyether ester 3#, further react polyether ester 3# with hydrogen-containing silicone oil to obtain branched silicon polyether 3#; the amount of branched silicon polyether 3# accounts for 30-60% of the total mass of the polyether ester defoamer;

[0010] The preparation method of the polyether ester defoamer is as follows: polyether ester 1#, polyether ester 2# and branched silicon polyether 3# are uniformly mixed according to a certain proportion to obtain the final polyether ester defoamer.

[0011] In the above polyetherester preparation process:

[0012] During the preparation of polyetherester 1#:

[0013] Glycidyl ether is selected from glycerol triglycidyl ether and pentaerythritol tetraglycidyl ether; short-chain alcohol is selected from one or more of ethylene glycol, glycerol and methyl propylene glycol; fatty acid is selected from C 6 -C 18 Fatty acids, preferably fatty acids C 6 -C 12 fatty acid;

[0014] The catalyst used in the ring-opening process is an amine catalyst, specifically selected from dimethylbenzylamine, triethanolamine, N,N-dimethylcyclohexylamine, and triethylamine; the catalyst used in the esterification process is an acid catalyst, specifically selected from concentrated sulfuric acid, p-toluenesulfonic acid, boric acid, and phosphoric acid;

[0015] During the ring-opening reaction, the molar ratio of glycidyl ether to short-chain alcohol is 1:1-1:3, and during the esterification reaction, the molar ratio of polyether 1# to fatty acid is 1:1-1:3. The amount of amine catalyst used accounts for 0.4-0.8% of the total mass of glycidyl ether and short-chain alcohol; the amount of acid catalyst used accounts for 0.4-0.8% of the total mass of polyether 1# and fatty acid.

[0016] During the preparation of polyetherester 2#:

[0017] The glycidyl ether is selected from glycerol triglycidyl ether and pentaerythritol tetraglycidyl ether; the long-chain alcohol is composed of polyethylene glycol and polypropylene glycol; the molecular weight of polyethylene glycol and polypropylene glycol is 200-2000; the fatty acid is selected from C 6 -C 18 Fatty acids, preferably fatty acids C 12 -C 18 fatty acid;

[0018] The catalyst used in the ring-opening process is an amine catalyst, specifically selected from dimethylbenzylamine, triethanolamine, N,N-dimethylcyclohexylamine, and triethylamine; the catalyst used in the esterification process is an acid catalyst, specifically selected from concentrated sulfuric acid, p-toluenesulfonic acid, boric acid, and phosphoric acid; the amount of the amine catalyst accounts for 0.4-0.8% of the total mass of the glycidyl ether and the long-chain alcohol; the amount of the acid catalyst accounts for 0.4-0.8% of the total mass of the polyether 2# and the fatty acid.

[0019] During the ring-opening reaction, the molar ratio of glycidyl ether to long-chain alcohol is 1:1-1:3, and during the esterification reaction, the molar ratio of polyether 2# to fatty acid is 1:1-1:3.

[0020] During the preparation of branched silicon polyether 3#:

[0021] The glycidyl ether is selected from glycerol triglycidyl ether and pentaerythritol tetraglycidyl ether; the molecular weight of the polypropylene glycol is 200-2000; the unsaturated fatty acid is selected from C 6 -C 18 Unsaturated fatty acid; the structural formula of hydrogen silicone oil is: (Me) 2 R 1 SiO(MeHSiO) m [(Me) 2 SiO] n Si(Me) 2 R 1 , where R 1 can be the same or different, and can be a hydrogen atom or a monovalent saturated C 1 -C 6 The number of hydrogen atoms in the hydrogen-containing silicone oil is ≥ 1; the subscript m is an integer from 1 to 20; the subscript n is an integer from 0 to 350, R 1 Preferably it is methyl;

[0022] The catalyst used in the ring-opening process is an amine catalyst, specifically selected from dimethylbenzylamine, triethanolamine, N,N-dimethylcyclohexylamine, and triethylamine; the catalyst used in the esterification process is an acid catalyst, specifically selected from concentrated sulfuric acid, p-toluenesulfonic acid, boric acid, and phosphoric acid; the amount of the amine catalyst accounts for 0.4-0.8% of the total mass of glycidyl ether and polypropylene glycol; the amount of the acid catalyst accounts for 0.4-0.8% of the total mass of polyether 3# and unsaturated fatty acids.

[0023] During the ring-opening reaction, the molar ratio of glycidyl ether to polypropylene glycol is 1:1-1:3, and during the esterification reaction, the molar ratio of polyether 3# to unsaturated fatty acid is 1:1-1:3; during the reaction of polyether ester 3# and hydrogen-containing silicone oil, the amount of hydrogen-containing silicone oil accounts for 20-40% of the total mass of polyether ester 3# and hydrogen-containing silicone oil; and the amount of chloroplatinic acid isopropanol catalyst accounts for 0.4%-0.8% of the total mass of polyether ester 3# and hydrogen-containing silicone oil. DETAILED DESCRIPTION

[0024] Examples and Comparative Examples of Polyether Ester 1#

[0025]

[0026]

[0027] Polyetherester 2# Example

[0028]

[0029]

[0030]

[0031] Hyperbranched Silicon Polyether 3# Example

[0032]

[0033]

[0034]

[0035] Polyetherester defoamer embodiment and comparative example

[0036] Example 1

[0037] 5 g of polyether ester 1# Example 1, 60 g of polyether ester 2# Example 2, and 35 g of branched silicon polyether 3# Example 1 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0038] Example 2

[0039] 10 g of polyether ester 1# Example 2, 50 g of polyether ester 2# Example 2, and 40 g of branched silicon polyether 3# Example 2 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0040] Example 3

[0041] 20 g of polyether ester 1# Example 3, 50 g of polyether ester 2# Example 3, and 30 g of branched silicon polyether 3# Example 3 were mixed uniformly in proportion to obtain the final polyether ester defoamer.

[0042] Example 4

[0043] 8 g of polyether ester 1# Example 4, 32 g of polyether ester 2# Example 4, and 60 g of branched silicon polyether 3# Example 4 were mixed uniformly in proportion to obtain the final polyether ester defoamer.

[0044] Example 5

[0045] 10 g of polyether ester 1# Example 5, 40 g of polyether ester 2# Example 5, and 50 g of branched silicon polyether 3# Example 5 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0046] Example 6

[0047] 18 g of polyether ester 1# Example 6, 30 g of polyether ester 2# Example 6, and 52 g of branched silicon polyether 3# Example 6 were mixed uniformly in proportion to obtain the final polyether ester defoamer.

[0048] Example 7

[0049] 16 g of polyether ester 1# Example 7, 45 g of polyether ester 2# Example 7, and 39 g of branched silicon polyether 3# Example 7 were mixed uniformly in proportion to obtain the final polyether ester defoamer.

[0050] Comparative Example 1

[0051] 20 g of polyether ester 1# Example 1 and 80 g of polyether ester 2# Example 1 were mixed uniformly according to the proportion to obtain the final polyether ester defoamer.

[0052] Comparative Example 2

[0053] 50 g of polyether ester 2# Example 2 and 50 g of branched silicon polyether 3# Example 2 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0054] Comparative Example 3

[0055] 40 g of polyether ester 1# Example 3 and 60 g of branched silicon polyether 3# Example 3 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0056] Comparative Example 4

[0057] 8 g of polyether ester 1# comparative example 1, 32 g of polyether ester 2# example 4, and 60 g of branched silicon polyether 3# example 4 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0058] Comparative Example 5

[0059] 10 g of polyether ester 1# Example 5, 40 g of polyether ester 2# Comparative Example 1, and 50 g of branched silicon polyether 3# Example 5 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0060] Comparative Example 6

[0061] 10 g of polyether ester 1# Example 5, 40 g of polyether ester 2# Comparative Example 2, and 50 g of branched silicon polyether 3# Example 5 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0062] Comparative Example 7

[0063] 10 g of polyether ester 1# Example 5, 40 g of polyether ester 2# Comparative Example 3, and 50 g of branched silicon polyether 3# Example 5 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0064] Comparative Example 8

[0065] 18 g of polyether ester 1# Example 6, 30 g of polyether ester 2# Example 6, and 52 g of branched silicon polyether 3# Comparative Example 1 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0066] Comparative Example 9

[0067] 18 g of polyether ester 1# Example 6, 30 g of polyether ester 2# Example 6, and 52 g of branched silicon polyether 3# Comparative Example 2 were mixed uniformly according to proportion to obtain the final polyether ester defoamer.

[0068] Performance Testing

[0069] Test method:

[0070] The first anti-foaming performance test:

[0071] Add 200ml of prepared paint to a 1000ml cup, then add 0.3% defoamer, use a laboratory high-speed disperser to disperse at 1000rpm for 10min, pour into a 1000ml measuring cylinder immediately after stopping, record the weight and volume of the liquid, calculate the specific gravity, and a large specific gravity value indicates a small gas content, indicating that the defoamer has good anti-foaming performance. Compatibility coating test:

[0072] Place the high-speed dispersed coating for 15 minutes, take out a small amount of static liquid and drop it on a clean glass plate, and use a wet film preparation device to scrape the emulsion at a uniform speed, observe the state of the emulsion on the glass plate (shrinkage condition), and express it with a grade. The higher the grade, the better the compatibility.

[0073]

[0074] The second anti-foaming performance test:

[0075] Place the paint that has been tested for defoaming and antifoaming performance for the first time for 7 days, pour it into a 1000ml measuring cylinder again, record the weight and volume of the liquid, and calculate the specific gravity. A larger specific gravity value indicates a smaller air content, indicating that the defoaming agent has good defoaming performance.

[0076] Test results:

[0077]

[0078] It can be seen from the above examples and comparative examples that the coatings of Examples 1 to 7 have good compatibility, and after being placed for 7 days, the anti-foaming performance decays less.

[0079] Comparative Example 1 removes the hyperbranched silicon polyether 3# in Example 1, Comparative Example 2 removes the polyether ester 1# in Example 2, and Comparative Example 3 removes the polyether ester 2# in Example 3. The foam suppression performance, attenuation and compatibility of Comparative Examples 1 to Comparative Examples 3 are all worse than those of Examples 1 to 3.

[0080] Comparative Example 4 adjusts the type of polyether in the synthesis process of polyether ester 1# in Example 4, Comparative Examples 5-7 adjust the type of polyether in the synthesis process of polyether ester 2# in Example 5, and Comparative Examples 8-9 adjust the polyether and hydrogen-containing silicone oil in the synthesis process of hyperbranched polyether 3# in Example 6. The antifoaming performance, attenuation and compatibility of Comparative Examples 4-9 are all worse than those of Example 4 and Example 6.

Claims

1. A method for preparing a polyetherester defoamer, characterized in that: It is composed of the following components: Polyether ester 1#: Polyether 1# is prepared by ring-opening reaction of glycidyl ether and short-chain alcohol, and finally polyether ester 1# is prepared by esterification reaction with fatty acid; the amount of polyether ester 1# accounts for 5-20% of the total mass of polyether ester defoamer; Polyether ester 2#: Polyether 2# is prepared by ring-opening reaction of glycidyl ether and long-chain alcohol, and finally polyether ester 2# is prepared by esterification reaction with fatty acid; the amount of polyether ester 2# accounts for 30-60% of the total mass of polyether ester defoamer; Branched silicon polyether 3#: Prepare polyether 3# by ring-opening reaction of glycidyl ether and polypropylene glycol, then further esterify with unsaturated fatty acid to obtain polyether ester 3#, and then further react polyether ester 3# with hydrogen-containing silicone oil to obtain branched silicon polyether 3#; the amount of branched silicon polyether 3# accounts for 30-60% of the total mass of polyether ester defoamer; The preparation method of the polyether ester defoamer is as follows: polyether ester 1#, polyether ester 2# and branched silicon polyether 3# are uniformly mixed according to a certain proportion to obtain the final polyether ester defoamer.

2. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of polyetherester 1#: Glycidyl ether is selected from glycerol triglycidyl ether and pentaerythritol tetraglycidyl ether; short-chain alcohol is selected from one or more of ethylene glycol, glycerol and methyl propylene glycol; fatty acid is selected from C6-C 18 Fatty acids, preferably fatty acids of C6-C 12 fatty acid.

3. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of polyetherester 1#: the catalyst used in the ring-opening process is an amine catalyst, specifically selected from dimethylbenzylamine, triethanolamine, N,N-dimethylcyclohexylamine, and triethylamine; the catalyst used in the esterification process is an acid catalyst, specifically selected from concentrated sulfuric acid, p-toluenesulfonic acid, boric acid, and phosphoric acid.

4. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of polyetherester 1#: in the ring-opening reaction, the molar ratio of glycidyl ether to short-chain alcohol is 1:1-1:3, and the molar ratio of polyether 1# to fatty acid during the esterification reaction is: 1:1-1:3; the amount of amine catalyst used accounts for 0.4-0.8% of the total mass of glycidyl ether and short-chain alcohol; the amount of acid catalyst used accounts for 0.4-0.8% of the total mass of polyether 1# and fatty acid.

5. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of polyetherester 2#: The glycidyl ether is selected from glycerol triglycidyl ether and pentaerythritol tetraglycidyl ether; the long-chain alcohol is composed of polyethylene glycol and polypropylene glycol; the molecular weight of polyethylene glycol and polypropylene glycol is 200-2000; the fatty acid is selected from C6-C 18 Fatty acids, preferably fatty acids C 12 -C 18 fatty acid.

6. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of polyetherester 2#: The catalyst used in the ring-opening reaction is an amine catalyst, specifically selected from dimethylbenzylamine, triethanolamine, N,N-dimethylcyclohexylamine, and triethylamine; the catalyst used in the esterification process is an acid catalyst, specifically selected from concentrated sulfuric acid, p-toluenesulfonic acid, boric acid, and phosphoric acid; the amount of the amine catalyst accounts for 0.4-0.8% of the total mass of the glycidyl ether and the long-chain alcohol; the amount of the acid catalyst accounts for 0.4-0.8% of the total mass of the polyether 2# and the fatty acid.

7. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of polyetherester 2#: During the ring-opening reaction, the molar ratio of glycidyl ether to long-chain alcohol is 1:1-1:3, and during the esterification reaction, the molar ratio of polyether 2# to fatty acid is 1:1-1:

3.

8. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: In the preparation process of branched silicon polyether 3#: the glycidyl ether is selected from glycerol triglycidyl ether and pentaerythritol tetraglycidyl ether; the molecular weight of polypropylene glycol is 200-2000; the unsaturated fatty acid is selected from C6-C 18 Unsaturated fatty acid; the structural formula of hydrogen-containing silicone oil is: (Me)2R1SiO(MeHSiO) m [(Me)2SiO] n Si(Me)2R1, wherein R1 may be the same or different, and is a hydrogen atom or a monovalent saturated C1-C6 hydrocarbon group, and the number of hydrogen atoms in the hydrogen-containing silicone oil is ≥1; the subscript m is an integer from 1 to 20; the subscript n is an integer from 0 to 350, and R1 is preferably a methyl group.

9. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: In the preparation process of branched silicon polyether 3#: the catalyst used in the ring-opening reaction is an amine catalyst, specifically selected from dimethylbenzylamine, triethanolamine, N,N-dimethylcyclohexylamine, and triethylamine; the catalyst used in the esterification process is an acid catalyst, specifically selected from concentrated sulfuric acid, p-toluenesulfonic acid, boric acid, and phosphoric acid; the amount of the amine catalyst accounts for 0.4-0.8% of the total mass of glycidyl ether and polypropylene glycol; the amount of the acid catalyst accounts for 0.4-0.8% of the total mass of polyether 3# and unsaturated fatty acids.

10. The method for preparing a polyetherester defoamer according to claim 1, characterized in that: During the preparation of branched silicon polyether 3#, the molar ratio of glycidyl ether to polypropylene glycol is 1:1-1:3, and the molar ratio of polyether 3# to unsaturated fatty acid during the esterification reaction is 1:1-1:3; during the reaction of polyether ester 3# and hydrogen-containing silicone oil, the amount of hydrogen-containing silicone oil accounts for 20-40% of the total mass of polyether ester 3# and hydrogen-containing silicone oil; the amount of chloroplatinic acid isopropanol catalyst accounts for 0.4%-0.8% of the total mass of polyether ester 3# and hydrogen-containing silicone oil.

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