Modified organic silicon defoaming agent as well as preparation method and application thereof
The preparation of ternary copolymer modified organosilicon defoamer solved the problem of poor defoaming effect in high-temperature and high-speed papermaking process, and achieved rapid dispersion, defoaming and degassing effects, thereby improving the operating efficiency of paper machine system and paper quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG TRANSFAR WHYYON CHEM
- Filing Date
- 2026-02-09
- Publication Date
- 2026-05-01
AI Technical Summary
Existing high-carbon alcohol defoamers have poor defoaming effects in high-temperature, high-speed papermaking processes, and cannot effectively remove fine fiber foam. Furthermore, the defoamers exhibit poor dispersibility and stability when the temperature changes, affecting the operation of the paper machine system and the quality of the finished paper.
A modified organosilicon defoamer was prepared using a ternary copolymer of hydrogen-containing silicone oil, alkynes, and enols. Through addition reaction and high-temperature phase inversion emulsification, a three-dimensional modified organosilicon defoamer was formed, which enhanced the bonding strength and dispersibility with the fiber surface at high temperatures.
It improves the defoaming efficiency of defoamers in high-temperature, high-speed paper machines, reduces the air content in the system, reduces paper defects, and improves the operating efficiency of paper machines. It also has good chemical stability, is heat-resistant, and resistant to acids, alkalis, and salts, making it suitable for high-temperature, high-speed cultural paper machines.
Smart Images
Figure CN121944604A_ABST
Abstract
Description
A modified organosilicon defoamer, its preparation method and application Technical Field
[0001] This invention belongs to the field of papermaking defoamer technology, specifically a modified organosilicon defoamer, its preparation method, and its application. Background Technology
[0002] During papermaking, air is enveloped by a liquid film of pulp, white water, or coating, forming a stable gas-liquid interface (foam). Surfactants adsorb at the gas-liquid interface, reducing surface tension and preventing the liquid film from rupturing, thus allowing the foam to exist stably for a long time. The presence of foam affects the smooth operation of the paper machine system, leading to difficulties in dewatering the forming wire, longer water lines, and ultimately affecting the quality of the finished paper.
[0003] The papermaking process for cultural paper is a high-speed, high-temperature process (the machine speed is generally around 1500 m / min, and the paper machine system temperature is generally 50-60℃). High machine speeds make it easier for foam to be generated in the system, affecting production. Typically, high-grade fatty alcohol defoamers are chosen for cultural paper systems. These defoamers have an amphiphilic structure; the hydrophilic end can quickly wet the fiber surface, while the hydrophobic end can displace attached microbubbles, causing them to peel off, merge, and float. This results in rapid defoaming and removal of gas from the pulp, with minimal impact on paper sizing, making it an excellent choice for white water systems in cultural paper production.
[0004] However, high-carbon alcohol defoamers are quite sensitive to temperature. At low temperatures, fatty alcohols with high carbon chain structures will reduce the dispersibility of the defoamer in white water, resulting in poor defoaming and degassing. At high temperatures, the hydrophobic ends of fatty alcohols with low carbon chain structures will not bond firmly with the hydrophobic points on the surface of the system fibers, making them prone to desorption and causing defoaming failure.
[0005] Higher alcohol defoamers tend to remove foam from fine fibers and cannot simultaneously be effective against both fine fibers and large system bubbles. Summary of the Invention
[0006] To address the shortcomings of the existing technology, this invention provides a method for preparing a modified organosilicon defoamer with a short reaction cycle and convenient operation. The prepared defoamer is then applied to the papermaking process, especially high-speed cultural paper machines, which can improve defoaming efficiency, reduce system air content, reduce paper defects, and improve paper machine operating efficiency.
[0007] Therefore, the present invention adopts the following technical solution.
[0008] In a first aspect, the present invention provides a method for preparing a modified organosilicon defoamer, comprising the steps of:
[0009] 1) Place hydrogen-containing silicone oil, alkyne, and enol in a reaction vessel, start stirring to carry out an addition reaction, raise the temperature to the first temperature, add a catalyst, continue to raise the temperature to the second temperature, keep it at the temperature for a period of time, and then cool down to obtain an intermediate of modified organosilicon defoamer; 2) Raise the intermediate of modified organosilicon defoamer with docosyl alcohol, octadecyl alcohol, and emulsifier to the third temperature for high-temperature phase inversion emulsification, keep it at the temperature for a period of time, add deionized water at the third temperature, stir rapidly for a period of time, and then cool down to room temperature to obtain modified organosilicon defoamer.
[0010] The structure of the modified silicone defoamer is as follows:
[0011] This invention utilizes a ternary copolymer of aliphatic hydrocarbons containing alkynyl groups, enols containing hydroxyl groups, and hydrogen-containing silicone oils containing active hydrogen. The alkynyl group breaks to form an alkenyl group, and the alkenyl group continues to break bonds, forming a ternary copolymer. Organosilicon is a polymer with a Si-O-Si (siloxane) main chain and organic groups (such as methyl and phenyl) as side chains; it is inherently a relatively inert material. Alkyne groups (-C≡C-) contain unsaturated triple bonds, while enols contain both double bonds and hydroxyl groups. Through chemical means, alkynyl groups and enols are introduced into the end groups or side chains of organosilicon molecules, forming a structure of "organosilicon backbone + alkynyl functional end / side group + enol". In this invention, triple-bonded alkynyl hydrocarbons are used instead of other substances containing double bonds. The main difference is that after the double bond breaks, an organosilicon segment is generally grafted. If the hydrogen-containing form is terminal hydrogen, the modified product is usually linear; if the hydrogen-containing form is side hydrogen, the modified product is planar. However, triple-bonded alkyne-modified organosilicon is usually stereochemical. After the alkyne group breaks twice, a single bond is formed, resulting in two hydrogen-containing silicone oil segments bonded to a carbon atom at the head of the alkyne. This creates a polymer with a relatively large steric hindrance, and the surface tension of this polymer is usually below 20 mN / m, which can improve the dispersibility and defoaming properties of defoamer particles in paper machine systems. The use of enols, mainly the combination of organosilicon and higher alcohols, can enhance the binding strength of higher alcohols on the surface of fine fibers and improve their degassing performance at high temperatures. The ternary copolymer of organosilicon, alkyne, and enol demonstrates not only the rapid dispersibility and defoaming properties of the defoamer but also its degassing properties in the pulp.
[0012] Further, the molar ratio of the hydrogen-containing silicone oil, alkyne and enol is 1:(0.2-0.4):(0.2-0.6).
[0013] Furthermore, the hydrogen-containing silicone oil contains hydrogen in the form of side-containing hydrogen, double-end hydrogen, or end-side hydrogen, with a hydrogen content of 0.05-0.3%; the alkynes have a carbon chain number of C16-C36; and the enols are monohydric alcohols with a carbon chain number of C16-C24.
[0014] Furthermore, the catalyst is chloroplatinic acid, and the amount added is 5-20 ppm.
[0015] Furthermore, the first temperature is 50-70℃, the second temperature is 90-120℃, and the third temperature is 80-100℃.
[0016] Furthermore, the emulsifier is one or a mixture of linear C12-14 fatty alcohol polyoxyethylene ether, octadecyl alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and isomeric tridecyl alcohol polyoxyethylene ether.
[0017] Furthermore, the weight parts of each raw material used in emulsification are as follows: 5-15 parts of the intermediate of modified silicone defoamer, 5-15 parts of docosyl alcohol, 5-10 parts of octadecyl alcohol, 1-3 parts of emulsifier, and 70 parts of deionized water at the third temperature.
[0018] Further, continue heating to the second temperature and hold for 0.5-1.5 hours.
[0019] Further, high-temperature phase-inversion emulsification is carried out and kept at this temperature for 0.5-1.5 hours; then deionized water at a third temperature is added and the mixture is stirred rapidly for 15-45 minutes.
[0020] Secondly, the present invention provides a modified organosilicon defoamer prepared by the above preparation method.
[0021] Thirdly, the present invention provides the application of the modified organosilicon defoamer prepared by the above preparation method in the papermaking process, especially in the application of high-speed cultural paper machines.
[0022] In the high-temperature, high-speed white water of cultural paper, the presence of surfactants such as ASA, AKD, and pigments in the system leads to numerous tiny bubbles on the fiber surface, resulting in paper defects. The modified organosilicon defoamer of this invention not only allows the hydrocarbon segments of the aliphatic chain to disperse well in the white water, eliminating surface foam, but also ensures that the hydroxyl groups in the copolymer are firmly bonded to the hydroxyl groups on the ester fiber surface, preventing desorption as the temperature rises, thus achieving the effect of degassing and removing foam.
[0023] The beneficial effects of this invention are as follows: 1. A novel ternary copolymer is synthesized by adding hydrogen-containing silicone oil, alkyne and enol, and this novel polymer is applied to the preparation of defoamers, thus preparing a defoamer that can be used in high-temperature and high-speed paper machines.
[0024] 2. Using alkynes as organosilicon modifiers further reduces surface tension and improves the rapid dispersion and defoaming performance of alkynes in paper machine white water; using oleyl alcohol as copolymer modifiers reacts high-carbon alcohols with organosilicon to improve the degassing performance of fine fibers. The ternary copolymerization combines the characteristics of rapid dispersion, rapid defoaming, and good degassing, making it more suitable for eliminating foam in high-temperature and high-speed cultural paper, solving the problems of slow defoaming and poor degassing in white water of traditional defoamers.
[0025] 3. The defoamer prepared by this invention has low surface tension, good chemical stability, and is resistant to heat, acids, alkalis, salts, and high-temperature systems.
[0026] 4. The defoamer of the present invention is applied to the papermaking section of a high-temperature, high-speed cultural paper machine. It has very little negative impact on the paper machine system and the finished paper. It also has the characteristics of low dosage, fast defoaming speed, strong foam suppression ability, non-toxicity, harmlessness, and simple process. Attached Figure Description
[0027] Figure 1 is a comparison of the defoaming and foam-suppressing performance of the modified organosilicon defoamer of the present invention in white water for cultural paper. Detailed Implementation
[0028] The present invention will be further described in detail below with reference to the embodiments, but this should not be construed as limiting the present invention in any way.
[0029] In a comparative example, docosyl alcohol, octadecyl alcohol, and emulsifier were placed in a reaction vessel and heated to 85°C. The mixture was kept at this temperature for 1 hour, then deionized water at 85°C was added. The mixture was stirred rapidly for 30 minutes and then cooled to 25°C to obtain a high-grade fatty alcohol defoamer.
[0030] Defoaming test method: Take 300g of white water for cultural paper, heat it to 60℃, place it in a circulating bubbler, turn on the circulating pump, and when the foam liquid level reaches the 1000ml mark, add defoaming agent, start timing, and record the foam height data at 5s, 15s, 30s, 45s, 60s, ...
[0031] Gas content test method: Take 800g of white water from cultural paper, heat it to 60℃, place it in a circulating bubbler, turn on the circulating pump, add defoamer, circulate for 2 minutes, and then immediately transfer the white water to an air content analyzer (EGT) to test the gas content.
[0032] Example 1 This example provides a method for preparing a modified organosilicon defoamer, the steps of which are as follows: 1) Hydrogen-containing silicone oil (hydrogen-containing method: side-hydrogen, hydrogen content: 0.3%), alkyne (carbon chain number: C16), and enol (carbon chain number 24) are placed in a reaction vessel at a molar ratio of 1:0.2:0.6, stirring is started, the temperature is raised to 50°C, 20ppm chloroplatinic acid catalyst is added, the temperature is further raised to 90°C, and the temperature is maintained for 0.5h. The temperature is then lowered to obtain an alkyne-modified organosilicon defoamer intermediate; 2) 8 parts of the intermediate, 15 parts of docosyl alcohol, 6 parts of octadecyl alcohol, and 1 part of linear C12-14 fatty alcohol polyoxyethylene ether are used, the temperature is raised to 80°C, and the temperature is maintained for 1h. 70 parts of deionized water at 80°C are added, the mixture is stirred rapidly for 30min, and the temperature is lowered to room temperature to obtain the defoamer.
[0033] Defoaming test method: Take 300g of white water for cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, when the foam liquid level reaches the 1000ml mark, add defoaming agent, start timing, and record the foam height data at 5s, 15s, 30s, 45s, 60s, ...
[0034] Gas content test method: Take 800g of white water from cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, add defoamer, circulate for 2 minutes, and then immediately transfer the white water to an EGT to test the gas content.
[0035] Example 2 This example provides a method for preparing a modified organosilicon defoamer, the steps of which are as follows: 1) Hydrogen-containing silicone oil (hydrogen-containing method: double-end hydrogen, hydrogen content: 0.05%), alkyne (carbon chain number: C36), and enol (carbon chain number: C16) are placed in a reaction vessel in a molar ratio of 1:0.4:0.2, stirring is started, the temperature is raised to 70°C, 5ppm chloroplatinic acid catalyst is added, the temperature is further raised to 120°C, and the temperature is maintained for 0.5h. The temperature is then lowered to obtain an alkyne-modified organosilicon defoamer intermediate; 2) 15 parts of the intermediate, 5 parts of docosyl alcohol, 8 parts of octadecyl alcohol, and 2 parts of octadecyl alcohol polyoxyethylene ether are used, the temperature is raised to 100°C, and the temperature is maintained for 1h. 70 parts of deionized water at 100°C are added, the mixture is stirred rapidly for 30min, and the temperature is lowered to room temperature to obtain the defoamer.
[0036] Defoaming test method: Take 300g of white water for cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, when the foam liquid level reaches the 1000ml mark, add defoaming agent, start timing, and record the foam height data at 5s, 15s, 30s, 45s, 60s, ...
[0037] Gas content test method: Take 800g of white water from cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, add defoamer, circulate for 2 minutes, and then immediately transfer the white water to an EGT to test the gas content.
[0038] Example 3 This example provides a method for preparing a modified organosilicon defoamer, the steps of which are as follows: 1) Hydrogen-containing silicone oil (hydrogen-containing method: end-side hydrogen, hydrogen content: 0.1%), alkyne (carbon chain number: C24), and enol (carbon chain number: C18) are placed in a reaction vessel in a molar ratio of 1:0.3:0.4, stirring is started, the temperature is raised to 60°C, 10 ppm chloroplatinic acid catalyst is added, the temperature is further raised to 95°C, and the temperature is maintained for 2 hours. The temperature is then lowered to obtain an alkyne-modified organosilicon defoamer intermediate; 2) 12 parts of the intermediate, 10 parts of dodecyl alcohol, 5 parts of octadecyl alcohol, and 3 parts of nonylphenol polyoxyethylene ether are used. The temperature is raised to 90°C and maintained for 1 hour. 70 parts of deionized water at 90°C are added, and the mixture is stirred rapidly for 30 minutes. The temperature is then lowered to room temperature to obtain the defoamer.
[0039] Defoaming test method: Take 300g of white water for cultural paper, heat it to 60℃, place it in a circulating bubbler, turn on the circulating pump, when the foam liquid level reaches the 1000ml mark, add defoaming agent, start timing, and record the foam height data at 5s, 15s, 30s, 45s, 60s, etc.
[0040] Gas content test method: Take 800g of white water from cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, add defoamer, circulate for 2 minutes, and then immediately transfer the white water to an EGT to test the gas content.
[0041] Example 4 This example provides a method for preparing a modified organosilicon defoamer, the steps of which are as follows: 1) Hydrogen-containing silicone oil (hydrogen-containing method: side-hydrogen, hydrogen content: 0.2%), alkyne (carbon chain number: C30), and enol (carbon chain number: C22) are placed in a reaction vessel in a molar ratio of 1:0.3:0.4, stirring is started, the temperature is raised to 60°C, 15ppm chloroplatinic acid catalyst is added, the temperature is further raised to 95°C, and the temperature is maintained for 1.5h. The temperature is then lowered to obtain an alkyne-modified organosilicon defoamer intermediate; 2) Using 12 parts of the intermediate, 5 parts of docosyl alcohol, 10 parts of octadecyl alcohol, and 3 parts of isotridecyl alcohol polyoxyethylene ether, the temperature is raised to 85°C, and the temperature is maintained for 1h. 70 parts of deionized water at 85°C are added, and the mixture is stirred rapidly for 30min. The temperature is then lowered to room temperature to obtain the defoamer.
[0042] Defoaming test method: Take 300g of white water for cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, when the foam liquid level reaches the 1000ml mark, add defoaming agent, start timing, and record the foam height data at 5s, 15s, 30s, 45s, 60s, ...
[0043] Gas content test method: Take 800g of white water from cultural paper, heat it to 60℃, place it in a circulating bubble apparatus, turn on the circulating pump, add defoamer, circulate for 2 minutes, and then immediately transfer the white water to an EGT to test the gas content.
[0044] Table 1 Comparison of air content results of defoamer in white water of cultural paper
[0045] As can be seen from Table 1, in the high-speed cultural paper white water system, the degassing performance of the alkyne-modified organosilicon defoamer of this invention is better than that of ordinary high-carbon alcohol defoamers; as can be seen from Figure 1, the defoaming and foam-suppressing performance of the alkyne-modified organosilicon defoamer is significantly better than that of conventional high-carbon alcohol defoamers.
[0046] Therefore, the test results further confirm that the alkyne-modified organosilicon defoamer has a substantial improvement and significant progress in degassing, defoaming, and foam suppression in high-speed cultural paper white water.
[0047] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.
Claims
1. A method for preparing a modified organosilicon defoamer, characterized in that, The process includes the following steps: 1) placing hydrogen-containing silicone oil, alkynes, and enols in a reaction vessel, starting the stirrer to carry out an addition reaction, raising the temperature to the first temperature, adding the catalyst, continuing to raise the temperature to the second temperature, holding the temperature for a period of time, and then cooling down to obtain an intermediate of the modified organosilicon defoamer; 2) raising the intermediate of the modified organosilicon defoamer with docosyl alcohol, octadecyl alcohol, and emulsifier to the third temperature for high-temperature phase inversion emulsification, holding the temperature for a period of time, adding deionized water at the third temperature, stirring rapidly for a period of time, and then cooling down to room temperature to obtain the modified organosilicon defoamer.
2. The preparation method of the modified organosilicon defoamer according to claim 1, characterized in that, The molar ratio of the hydrogen-containing silicone oil, alkyne and enol is 1:(0.2-0.4):(0.2-0.6).
3. The method for preparing the modified organosilicon defoamer according to claim 1, characterized in that, Hydrogen-containing silicone oils contain hydrogen in the form of side-containing hydrogen, double-end hydrogen, or end-side hydrogen, with a hydrogen content of 0.05-0.3%; alkynes have a carbon chain number of C16-C36; and enols are monohydric alcohols with a carbon chain number of C16-C24.
4. The method for preparing the modified organosilicon defoamer according to claim 1, characterized in that, The catalyst is chloroplatinic acid, and the amount added is 5-20 ppm.
5. The method for preparing the modified organosilicon defoamer according to claim 1, characterized in that, The first temperature is 50-70℃, the second temperature is 90-120℃, and the third temperature is 80-100℃.
6. The method for preparing the modified organosilicon defoamer according to claim 1, characterized in that, The emulsifier is one or a mixture of linear C12-14 fatty alcohol polyoxyethylene ether, octadecyl alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and isomeric tridecyl alcohol polyoxyethylene ether.
7. The method for preparing the modified organosilicon defoamer according to claim 1, characterized in that, The weight parts of each raw material used in emulsification are as follows: 5-15 parts of intermediate of modified organosilicon defoamer, 5-15 parts of eicosyl alcohol, 5-10 parts of octadecyl alcohol, 1-3 parts of emulsifier, and 70 parts of deionized water at the third temperature.
8. The modified organosilicon defoamer prepared by the preparation method according to any one of claims 1-7.
9. The application of the modified organosilicon defoamer prepared by the preparation method according to any one of claims 1-7 in the papermaking process.
10. The application of the modified organosilicon defoamer prepared by the preparation method according to any one of claims 1-7 in a high-speed cultural paper machine.