CN102242523B - Antifoaming agent for low-temperature paper making system - Google Patents

Abstract

The invention provides a high-alcohol emulsion type antifoaming agent for a low-temperature paper making system. The antifoaming agent comprises the components of high alcohol, a nonionic surfactant, an anionic surfactant, high alcohol polyether ester, a wax-shaped substance, a thickening agent and water. In the invention, after the high alcohol polyether ester is introduced, the problem that the antifoaming effect of the high alcohol emulsion is poor under a low temperature condition is solved, thus the high alcohol emulsion can keep outstanding antifoaming performance under the low temperature paper making system, and the storage stability of the high alcohol emulsion can also be enhanced.

Description

A kind of defoamer for low temperature papermaking system

technical field

The invention relates to a defoamer for a papermaking system in the papermaking industry, which belongs to the technical field of fine chemical preparations.

technical background

The paper industry includes processes such as pulping, papermaking and coating. Due to the influence of various surface-active additives in wet-end chemistry, it is easy to produce a large amount of foam that is not easy to eliminate in water. At the same time, various plant fibers contained in pulping raw materials contain hydroxyl groups, which can easily make the fiber surface and A large amount of internal adsorption is difficult to remove fine bubbles and foam with ordinary defoamers, which seriously affects subsequent processes and product quality. Therefore, the selection and use of defoamers is particularly important for papermaking processes.

The main function of the papermaking defoamer is to peel off the air bubbles adsorbed on the fine fibers first, then make the small air bubbles gather into large bubbles and float to the liquid surface, and finally the air bubble film on the water surface becomes thinner and finally bursts. Existing defoamers for papermaking with better performance are usually high-carbon alcohol emulsion defoamers, which use high-carbon alcohol as the main active ingredient and form an oil-in-water emulsion by means of an emulsification process. For example, US4976888 discloses a high-carbon alcohol emulsion defoamer composed of high-carbon alcohol, high-carbon alcohol ester, high-boiling aliphatic hydrocarbon, polyethylene wax and emulsifier; The high-carbon alcohol emulsion defoamer that is made up of similar substance and emulsifier; US430359 discloses a kind of high-carbon alcohol emulsion defoamer that is made up of high-carbon alcohol, fatty acid and saponified emulsifier; EP0149812 discloses a kind of high-carbon alcohol, The high-carbon alcohol emulsion defoamer that high-carbon alcohol ester, high-boiling aliphatic hydrocarbon, water-soluble acrylic acid (acrylamide) polymer and emulsifier are formed; CA02493055 discloses a kind of by high-carbon alcohol, polyglycerol stearate, mineral High carbon alcohol emulsion defoamer composed of oil, ethylenediamine bisstearic acid amide, fatty acid ester and emulsifier.

Although the current papermaking technology continues to improve and the water temperature of white water is also on the rise, due to my country's vast territory and large climate differences between the north and the south, in winter, the water temperature of some enterprises is low when making paper, and the existing high-carbon alcohol Emulsion defoamers cannot adapt to foaming systems at low temperatures, so the ability to defoam and suppress foam becomes poor. At the same time, since the emulsion is a thermodynamically unstable system, the high-carbon alcohol emulsion defoamer is prone to phase separation after long-term storage or more likely after long-term storage at low temperature, which affects the use of the defoamer.

The present inventor has gone through a lot of experimental research and field application, by adding high-carbon alcohol polyether ester to it, can effectively solve the problem of the defoaming deterioration of high-carbon alcohol emulsion under low temperature conditions, and also strengthen the problem of high-carbon alcohol emulsion at the same time storage stability.

Contents of the invention

The object of the present invention is to provide a high-carbon alcohol emulsion type papermaking defoamer with excellent defoaming performance under low temperature conditions, which has good storage stability and mild preparation conditions.

The defoamer for the low temperature papermaking system of the present invention consists of the following components:

(1) High carbon alcohol. Higher alcohols suitable for the defoamer of the present invention include monohydric to trihydric alcohols with 12 to 28 carbon atoms, and the higher alcohols of the patent of the present invention are selected from lauryl alcohol, myristyl alcohol, cetyl alcohol, Stearyl Alcohol, Eicosanol, Behenyl Alcohol, Mycosyl Alcohol, and Octacosyl Alcohol. These alcohols are used alone or in combination of a plurality of alcohols.

(2) Nonionic surfactants. The general structural formula is as follows:

R ₁ O(EO) _m H

Wherein R ₁ is an n-alkyl group with 8 to 28 carbon atoms, and m is an integer of 10 to 60. Based on 100 parts by mass of the higher alcohol, the amount of the nonionic surfactant is 0.01-10 parts.

(3) Anionic surfactants. Disperse the antifoam active ingredient in water to form an O/W emulsion. Because it has a strong charge, after being adsorbed on the surface of the mixed fatty alcohol particles, it can make the fatty alcohol particles have a strong charge, thereby preventing the aggregation of particles. Its structural formula is as follows:

In the formula, _R2 is a saturated alkyl group with 8 to 20 carbon atoms. Based on 100 parts by mass of the higher alcohol, the amount of the emulsifier is 0.01-5 parts.

(4) High carbon alcohol polyether ester. Described higher carbon alcohol polyether ester is represented by following structural formula:

R ₃ O(EO) _x (PO) _y COR ₄

Wherein R ₃ is an alkyl group with 12 to 24 carbon atoms, x is an integer of 0 to 10, and y is an integer of 1 to 30; R ₄ is an alkyl group with 8 to 20 carbon atoms, and is an alkyl group with a higher carbon alcohol The dosage is based on 100 parts by mass, and the dosage of the polyether ester of bercol alcohol is 10-50 parts.

(5) Wax. The wax in the present invention is selected from paraffin wax, montan wax, microcrystalline wax, carnauba wax, oxidized polyethylene wax, Saso Fischer-Tropsch wax, polyethylene wax and beeswax. Based on 100 parts by mass of the high-carbon alcohol, the consumption of the waxy substance is 16-40 parts.

(6) thickener. The function of the thickener is to increase the stability of the emulsion. The thickener of the present invention comprises xanthan gum, guar gum, polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxyethyl cellulose and acrylic acid esters, preferably acrylic acid esters, and its consumption is according to actual needs Viscosity is adjusted.

(7) Water. The amount of water used determines the solid content of the final product, and the final solid content is preferably controlled at 0.1-35%, preferably 30%.

Prepare the high-carbon alcohol emulsion defoamer with the above components as follows: Stir and mix high-carbon alcohol, nonionic surfactant, anionic surfactant, high-carbon alcohol polyether ester, and wax evenly, and heat up to 70~ 95°C; slowly add water at 70-95°C to the above mixture, then further emulsify by high-speed shearing, and add an appropriate amount of water to the required concentration; finally, add a thickener to adjust to the required viscosity.

Detailed ways

Example 1

With 16 parts of stearyl alcohol, 6 parts of carnauba wax, 6 parts of higher alcohol polyether ester (C ₁₂ H ₂₆ O(EO) ₁ (PO) ₃₀ COC ₉ H ₁₉ ), 1 part of nonionic surfactant ( C ₁₂ H ₂₆ O(EO) ₄₀ H), 1 part of anionic emulsifier (sodium dodecyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 70°C, after stirring evenly, add 70 parts of 75°C The water is obtained by high-speed shearing equipment to obtain an emulsion, and an acrylic thickener is added to adjust the viscosity to obtain a defoamer.

Example 2

20 parts of eicosanol, 4 parts of microcrystalline wax, 4 parts of higher alcohol polyether ester (C ₁₆ H ₃₄ O(EO) ₅ (PO) ₂₀ COC ₁₃ H ₂₇ ), 1 part of nonionic surfactant ( C ₁₆ H ₃₄ O(EO) ₂₀ H), 1 part of anionic emulsifier (sodium octyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 85°C, after stirring evenly, add 70 parts of water at 75°C , obtain an emulsion through high-speed shearing equipment, add an acrylic thickener to adjust the viscosity, and obtain a defoamer.

Example 3

18 parts of tetracosanol, 6 parts of polyethylene wax, 4 parts of high carbon alcohol polyether ester (C ₂₂ H ₄₆ O(EO) ₉ (PO) ₈ COC ₁₅ H ₃₁ ), 1 part of nonionic surfactant (C ₂₀ H ₄₂ O(EO) ₆₀ H), 1 part of anionic emulsifier (sodium hexadecyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 90°C, after stirring evenly, add 70 parts of 75 °C water, through a high-speed shearing device to obtain an emulsion, adding an acrylic thickener to adjust the viscosity to obtain a defoamer.

Example 4

10 parts of stearyl alcohol, 6 parts of docosanol, 6 parts of paraffin, 6 parts of high carbon alcohol polyether ester (C ₁₄ H ₃₀ O(EO) ₉ (PO) ₂ COC ₁₉ H ₃₇ ), 1 part Add non-ionic surfactant (C ₁₄ H ₃₀ O(EO) ₄₀ H), 1 part of anionic emulsifier (sodium dodecyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 95°C, stir well , add 70 parts of water at 75°C, obtain an emulsion by high-speed shearing equipment, add an acrylate thickener to adjust the viscosity, and obtain a defoamer.

Example 5

10 parts of cetyl alcohol, 10 parts of eicosanol, 4 parts of carnauba wax, 2 parts of higher alcohol polyether ester (C ₂₀ H ₄₂ O(EO) ₇ (PO) ₁₀ COC ₁₁ H ₂₃ ), 1 1 part of nonionic surfactant (C ₁₈ H ₃₈ O(EO) ₂₀ H), 1 part of anionic emulsifier (sodium tetradecyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 80°C, stir well Finally, add 70 parts of water at 75°C, obtain an emulsion through high-speed shearing equipment, add an acrylate thickener to adjust the viscosity, and obtain a defoamer.

Example 6

8 parts of eicosanol, 10 parts of octacosanol, 4 parts of paraffin, 6 parts of higher alcohol polyether ester (C ₁₈ H ₃₈ O(EO) ₃ (PO) ₁₆ COC ₁₇ H ₃₅ ), 1 part Add non-ionic surfactant (C ₂₂ H ₄₆ O(EO) ₆₀ H), 1 part of anionic emulsifier (sodium octadecyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 90°C, stir well , add 70 parts of water at 75°C, obtain an emulsion by high-speed shearing equipment, add an acrylate thickener to adjust the viscosity, and obtain a defoamer.

Comparative example 1

With 10 parts of eicosanol, 12 parts of docosanol, 6 parts of microcrystalline wax, 1 part of nonionic surfactant (C ₈ H ₁₈ O(EO) ₆₀ H), 1 part of anionic emulsifier (12 Alkyl diphenyl ether disulfonate), add to the reaction kettle, mix and heat up to 87°C, stir evenly, add 70 parts of water at 75°C, obtain emulsion through high-speed shearing equipment, add acrylate thickener to adjust viscosity , to obtain a defoamer.

Comparative example 2

20 parts of stearyl alcohol, 8 parts of polyethylene wax, 1 part of nonionic surfactant (C ₁₂ H ₂₆ O(EO) ₄₀ H), 1 part of anionic emulsifier (sodium octyl diphenyl ether disulfonate) , add to the reaction kettle, mix and heat up to 90°C, after stirring evenly, add 70 parts of water at 75°C, obtain an emulsion through a high-speed shearing device, add an acrylate thickener to adjust the viscosity, and obtain a defoamer.

Performance Testing:

The defoamer in embodiment and comparative example is tested as follows:

1. Viscosity test

Viscosity test was carried out by NDJ-8 viscometer. Measure the viscosity change of the emulsion stored at 20°C and 40°C for a certain period of time. See Table 1 for details:

Table 1 Viscosity of high carbon alcohol emulsion defoamer

It can be seen from Table 1 that the viscosity of the emulsion added with part of the high-carbon alcohol polyether ester does not change significantly in 60 days, while the viscosity of the emulsion without the high-carbon alcohol polyether ester becomes larger.

2. Determination of anti-foam performance

Main instruments and devices: portable circulating bubbler

Test conditions: temperature 20°C, flow rate 9L/min, amount of defoamer added: 5ul

Test medium: corrugated white water

Specific test method: Clean the portable circulating bubbler, add a specified amount of foaming medium, heat to the set temperature, turn on the flow pump, and circulate the bubbles until the foam volume is 300ml at the set flow rate, and then add the specified amount The antifoaming agent sample, record the change of foam volume V with time. The lower the foam height in the same time, the better the defoaming performance.

The test results are as follows:

Table 2 Defoaming performance of high carbon alcohol emulsion

It can be seen from Table 2 that the high-carbon alcohol emulsion defoamer for papermaking prepared by the present invention has good defoaming and antifoaming properties at low temperatures.

Claims (3)

1. A defoamer for low-temperature papermaking system, characterized in that it consists of the following components: (1) Higher alcohols are monohydric to trihydric alcohols with 12 to 28 carbon atoms, and the higher alcohols are used alone or mixed with multiple alcohols; (2) Non-ionic surfactants, the general structural formula is: R ₁ O(EO) _m H, wherein R ₁ is an n-alkyl group with 8 to 28 carbon atoms, and m is an integer of 10 to 60; The consumption of carbon alcohol is 100 parts by mass, and the consumption of nonionic surfactant is 0.01～10 parts; (3) Anionic emulsifier, its general structural formula is as follows:

Wherein _R is a saturated alkyl group with 8 to 20 carbon atoms, and the consumption of higher alcohol is 100 parts by mass, and the consumption of anionic emulsifier is 0.01 to 5 parts; (4) Higher carbon alcohol polyether ester, the general structural formula is: R ₃ O(EO) _x (PO) _y COR ₄ , where R ₃ is an alkyl group with 12-24 carbon atoms; x is 0-10 Integer, y is an integer of 1 to 30; _R is an alkyl group with 8 to 20 carbon atoms; the amount of higher alcohol polyether ester is 10 to 50 parts based on 100 parts by mass of higher alcohol ; (5) Waxes, selected from paraffin wax, montan wax, microcrystalline wax, carnauba wax, oxidized polyethylene wax, Saso Fischer-Tropsch wax, polyethylene wax, carnauba wax and beeswax, with the amount of higher alcohol For 100 parts by mass, the amount of waxy substance is 16 to 40 parts; (6) thickener, selected from xanthan gum, guar gum, polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxyethyl cellulose and acrylates, the amount of which is adjusted according to the actual required viscosity; (7) water; The defoamer for the low-temperature papermaking system is prepared by the following method: Stir and mix high-carbon alcohol, nonionic surfactant, anionic surfactant, high-carbon alcohol polyether ester, and wax, and heat up to 70-95 ℃; slowly add water at 70~95℃ to the above mixture, and then further emulsify by high-speed shearing; add an appropriate amount of water to the required concentration; finally, add a thickener to adjust to the required viscosity. 2. The defoamer for a low-temperature papermaking system as claimed in claim 1, wherein the high-carbon alcohol described in (1) is selected from dodecanol, myristyl alcohol, cetyl alcohol, octadecane alcohol, eicosanol, docosanol, tetracosanol, and octacosanol. 3. A defoamer for low-temperature papermaking system according to claim 1, wherein the thickener described in (6) is an acrylate.