An oil-based antifoaming agent for pulp black liquor, a manufacturing method thereof, and an application thereof

Abstract

The application discloses an oil-based defoaming agent for pulp black liquor, a manufacturing method and application thereof, and belongs to the technical field of defoaming agents. The oil-based defoaming agent comprises the following components in parts by weight: 200 to 800 parts of a composite organosilicon silicone paste, 50 to 100 parts of a surfactant, 100 to 800 parts of a mineral solvent oil and 30 to 50 parts of a polyether modified silicone oil; the composite organosilicon silicone paste is mainly prepared from organosiloxane, fumed silica and silane coupling agent; the organosiloxane comprises dimethyl silicone oil with a viscosity of 300 mpa.s to 5000 mpa.s; the surfactant is selected from one or more of triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate, Span 80 and Tween 80; and the mineral solvent oil comprises D40 to D120 solvent oil and / or light oil. When the defoaming agent is used for defoaming treatment of pulp black liquor, the defoaming agent has the advantages of fast defoaming speed, long foam inhibiting time, less dosage and good application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemicals for kraft pulping and sulfite pulping, and particularly relates to an oil-based antifoaming agent for pulping black liquor, a manufacturing method and application thereof. BACKGROUND

[0002] The wastewater generated by kraft pulping and sulfite pulping processes contains a large amount of lignin and is commonly known as pulping black liquor due to its dark brown color. During the cooking process, a large amount of organic matter lignin is dissolved, and the composition also contains a large amount of surfactants such as fatty acid salts and hemicellulose, which reduces the surface tension of the water body and thus causes foaming and easy foaming. During the treatment of recovered black liquor in the yellow pulp screening and washing section after cooking and blow-off, a certain amount of silicone antifoaming agent must be added for defoaming, which can reduce the air content in the pulp, reduce the internal groove pressure of the double-roll washing machine under the premise of ensuring the washing effect of the washing machine, and increase the pulp layer thickness of the drum washing machine (GFF / DD washing machine), thereby improving the comprehensive production efficiency of defoaming and washing. SUMMARY

[0003] Therefore, the present application aims to provide an oil-based antifoaming agent for pulping black liquor, a manufacturing method and application thereof. The oil-based antifoaming agent can quickly eliminate foam, inhibit foam for a long time, and has a small dosage, which is beneficial to application.

[0004] The present application provides an oil-based antifoaming agent for pulping black liquor, which comprises the following components in parts by weight: 200-800 parts of a composite organosilicon paste, 50-100 parts of a surfactant, 100-800 parts of a mineral solvent oil, and 30-50 parts of a polyether-modified silicone oil.

[0005] The composite organosilicon paste is mainly prepared from organosiloxane, fumed silica and a silane coupling agent; the organosiloxane comprises dimethyl silicone oil with a viscosity of 300 mpa.s-5000 mpa.s.

[0006] The surfactant is selected from one or more of triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate, Span 80 and Tween 80.

[0007] The mineral solvent oil comprises D40-D120 solvent oil and / or light oil.

[0008] The antifoaming agent for pulping black liquor provided by the present application belongs to an oil-based antifoaming agent, and the effective component does not contain water (moisture content is less than 0.5%). When the antifoaming agent is used for defoaming pulping black liquor, the defoaming speed is fast, the foam inhibition time is long, the dosage is small, and the antifoaming agent has good defoaming and foam inhibition effects.

[0009] The oil-based defoaming agent according to the embodiment of the present application comprises 200-800 parts of the composite silicone paste, preferably 700-800 parts. The composite silicone paste is a composite paste mainly comprising dimethyl silicone oil (polydimethylsiloxane), and the polydimethylsiloxane has a low surface tension. The silicone paste is prepared by using organosiloxane, fumed silica and silane coupling agent as raw materials, wherein the organosiloxane comprises dimethyl silicone oil with viscosity of 300-5000 mpa.s, and the viscosity is generally measured at room temperature, for example, 20-30°C.

[0010] Preferably, in the raw materials of the composite silicone paste, the organosiloxane is composed of first dimethyl silicone oil with viscosity of 300-400 mpa.s, second dimethyl silicone oil with viscosity of 500-800 mpa.s, third dimethyl silicone oil with viscosity of 900-1200 mpa.s, fourth dimethyl silicone oil with viscosity of 1800-2100 mpa.s and fifth dimethyl silicone oil with viscosity of 3500-5000 mpa.s, and the weight ratio of the first, second, third, fourth and fifth dimethyl silicone oils is 20-200:20-200:20-200:20-600:20-200. For the sake of distinction, the dimethyl silicone oils with different viscosities are referred to as first, second, third, fourth and fifth dimethyl silicone oils, and the dimethyl silicone oils are also directly referred to as organosiloxane, and the mixture thereof is referred to as composite organosiloxane.

[0011] Further, the composite organosiloxane comprises five kinds of dimethyl silicone oils with viscosity of 300 mpa.s, 500 mpa.s, 1000 mpa.s, 2000 mpa.s and 5000 mpa.s, and specifically comprises:

[0012] organosiloxane (300 mpa.s) 20-200 parts;

[0013] organosiloxane (500 mpa.s) 20-200 parts;

[0014] organosiloxane (1000 mpa.s) 20-200 parts;

[0015] organosiloxane (2000 mpa.s) 20-600 parts;

[0016] organosiloxane (5000 mpa.s) 20-200 parts.

[0017] Further, the composite organosiloxane comprises:

[0018] organosiloxane (300 mpa.s) 20-150 parts, preferably 80-120 parts;

[0019] Organosiloxane (500 mpa.s) 20-200 parts, preferably 80-120 parts;

[0020] Organosiloxane (1000 mpa.s) 20-200 parts, preferably 80-120 parts;

[0021] Organosiloxane (2000 mpa.s) 20-600 parts, preferably 300-580 parts;

[0022] Organosiloxane (5000 mpa.s) 20-200 parts, preferably 50-100 parts.

[0023] In the embodiments of the present application, the composite organosiloxane, fumed silica, dimethyl and vinyl composite silane coupling agent can be sequentially added and mixed to prepare the silicone paste. The fumed silica has the formula SiO2, is produced by chemical vapor deposition, has a relatively large specific surface area, and has strong surface adsorption.

[0024] In the raw material of the composite organosilicone paste, the fumed silica is stable in nature and is not easily decomposed under the conditions of a strong alkaline of 150-250 g / L and a temperature of 80-95°C, which is beneficial to improving the defoaming and bubble suppressing effects.

[0025] Preferably, in the raw material of the composite organosilicone paste, the fumed silica has a specific surface area of 130-230 m 2 / g.

[0026] In some embodiments, the fumed silica can be one or more of hydrophobic silica or hydrophilic silica, and preferably components with different specific surface areas are used. In the embodiments of the present application, composite fumed silica produced by Wacker can be used, and specifically includes:

[0027] First fumed silica (such as V15, 130-170 m 2 / g) 10-30 parts, preferably 15-25 parts;

[0028] Second fumed silica (such as N20, 175-225 m 2 / g) 10-30 parts, preferably 15-25 parts.

[0029] Further, the silane coupling agent is preferably vinyltris(butanone oxime) silane and / or dimethyldimethoxysilane. Further, the silane coupling agent is vinyltris(butanone oxime) silane and dimethyldimethoxysilane; the mass percentage concentration of the silane coupling agent can be 2% to 3%. In some embodiments, the silane coupling agent includes: 5 to 25 parts, preferably 10 to 15 parts, of vinyltris(butanone oxime) silane; and 5 to 25 parts, preferably 10 to 15 parts, of dimethyldimethoxysilane.

[0030] In embodiments of the present application, the composite silicone paste is preferably prepared from the following components: 900 to 1000 parts of organosiloxane, 30 to 60 parts of fumed silica, and 15 to 50 parts of dimethyl and vinyl composite silane coupling agent, based on the weight fraction of the composite silicone paste.

[0031] Preferably, the raw materials of the composite silicone paste further include methyl MQ silicone resin. Methyl MQ silicone resin is a kind of organic silicone polymer material with Si-O bond as the molecular skeleton and a three-dimensional (non-linear) structure. The methyl MQ silicone resin is added during the synthesis of the defoaming agent. Under the catalysis of strong alkali, Si-OH can undergo complex chain scission, condensation and crosslinking reactions, generating a polymer with a high degree of branching and a space network structure, thereby improving the high-temperature resistance and strong alkali resistance of the defoaming agent.

[0032] Preferably, the M / Q ratio of the MQ silicone resin is 0.70, which has a great influence on the foam suppression performance of the defoaming agent. Specifically, the MQ silicone resin has an active substance solid content of ≥99% and is in the form of white particles or powder. Generally, the MQ silicone resin is added to the silicone oil before the synthesis of the defoaming agent organic silicone paste and is dissolved at high temperature. The addition amount is generally 1% to 3% of the total amount of the silicone oil.

[0033] Further, the weight ratio of the organosiloxane, fumed silica, silane coupling agent and methyl MQ silicone resin is 100 to 1200:20 to 60:10 to 50:1 to 30.

[0034] In the present application, the preparation of the composite silicone paste includes mixing the organosiloxane, fumed silica and silane coupling agent, and optionally the methyl MQ silicone resin, and then reacting to obtain the composite silicone paste.

[0035] Preferably, the organosiloxane, methyl MQ silicone resin, fumed silica and silane coupling agent are mixed, heated to 105°C to 150°C after the addition is completed, and then kept at temperature for 3 to 9 hours. Then, the pressure is increased and vacuum is extracted to -0.08 MPa. After 0.5 to 2.5 hours, the composite silicone paste is obtained.

[0036] The preparation method of the composite silicone silicone paste further comprises the following steps:

[0037] 1000 kg of polydimethylsiloxane (silicone oil), 0-30 kg of methyl MQ silicone resin, stirring at 50-100 rpm, electric heating to 150-200 DEG C, holding for 3-12 hours; after adding 60 kg of fumed silica, holding for 1-8 hours; adding 25 kg of dimethyl dimethoxysilane and 25 kg of vinyl tributyl ketoxime silane mixture as coupling agent, after adding the materials, heating to 105 DEG C-150 DEG C (about 1-4 hours), holding for 3-8 hours; continuing to heat to 150 DEG C under normal pressure (0.5-4 hours), then pressurized vacuum extraction to-0.08 MPa (about 1-4 hours; normal temperature and pressure holding), breaking the vacuum, cooling to 60 DEG C-80 DEG C (about 3-8 hours) below by cooling water, and naturally cooling to the discharge temperature, thus obtaining the product; about 10-24 hours.

[0038] In addition to the silicone paste, the oil-based defoaming agent comprises 50-100 parts by weight of a surfactant and 100-650 parts by weight of a mineral solvent oil. The surfactant comprises one or a mixture of several of triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate (preferably sodium fatty alcohol polyoxyethylene ether sulfate, AES), Span 80 (S-80) and Tween 80, preferably a plurality of complex.

[0039] Preferably, the surfactant is composed of triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate, Span 80 and Tween 80, which can be referred to as a composite surfactant; the weight ratio of the triethanolamine oleic acid soap, the fatty alcohol polyoxyethylene ether sulfate, the Span 80 and the Tween 80 is 10-30:10-20:10-30:10-30, and the complexing effect is better.

[0040] In the embodiment of the present application, the composite surfactant is 50-100 parts by weight, preferably 60-80 parts by weight, and the surfactant comprises one or a mixture of several of triethanolamine oleic acid soap, sodium fatty alcohol polyoxyethylene ether sulfate, Span 80 and Tween 80. The composite surfactant in the embodiment of the present application specifically comprises:

[0041]

[0042] Among them, ① fatty alcohol polyoxyethylene ether sodium sulfate: also known as AES, is an anionic surfactive agent, is a modified product of nonionic fatty alcohol polyoxyethylene ether (AE) sulfated by sulfuric acid and neutralized by alkaline neutralizer, the molecular structure has oxyethylene group and sulfated group, has the performance of nonionic and anionic surfactive agent, has strong wetting, dispersing, emulsifying and decontamination power, its surface tension is low, and its critical gel concentration is small. ② Triethanolamine oleic acid soap, also known as triethanolamine oleate, is a nonionic surfactive agent, has excellent emulsifying and dispersing performance; strong foaming capacity, fine foam; strong stability in acidic and alkaline medium; good washing and antirust ability. More flowable than sodium soap or zinc soap, the material is soft and delicate, and has good stability. ③ Tween 80: also known as T-80, is a nonionic surfactive agent and poly sorbate in emulsifier, is polyethylene glycol etherized octanol styrene acid ester and its derivative. Because Tween has excellent permeability and wetting property, it can reduce the surface tension of liquid. ④ Span 80: also known as Span-80 or sorbitan fatty acid ester, is a lipophilic nonionic surfactive agent, refers to a low molecular weight polyether, has excellent emulsifying stability, lubricity, thickening and dispersing effect.

[0043] In the present application, the mineral solvent oil includes D40-D120 solvent oil and / or light oil, preferably a plurality of complex compounds are formed into a composite type; based on the weight fraction of the composite mineral solvent oil, the composite mineral solvent oil is preferably 100-650 parts, more preferably 100-200 parts, such as 115 parts, 130 parts, 190 parts, etc. That is, the mineral solvent oil can be one or a mixture of several kinds of D40, D100, D120 and light oil.

[0044] Preferably, the mineral solvent oil is composed of D40 solvent oil, D100 solvent oil, D120 solvent oil and light oil, and the weight ratio of the D40 solvent oil, D100 solvent oil, D120 solvent oil and light oil is 20-300:20-300:20-300:20-200. The D40 solvent oil is prepared by deep hydrogenation of distillate oil or low-sulfur straight-run aviation kerosene. The D40 solvent oil belongs to environmentally friendly solvent oil, and is named by the flash point of 40°C (other solvent oil names are similar), and its characteristic is that the saturated hydrocarbon content is greater than 99%. Light oil, also known as naphtha or white naphtha, is an oil product obtained by refining crude oil, and is usually obtained by direct distillation of crude oil or by hydrogenation of secondary processed gasoline. It is composed of different carbon hydrocarbons, and the main component is chain alkane, cycloalkane or aromatic hydrocarbon containing 5-11 carbon atoms. Light oil is a colorless and transparent or slightly yellow liquid at normal temperature and pressure, has a special smell, and is insoluble in water. The light oil selected in the present application is a light oil product obtained by distillation of crude oil or secondary processing of petroleum, and the density is generally 700-800 kg / m 3which has a low viscosity (≤ 10 cSt) and a volatile temperature (≤ 150°C), a sulfur content ≤ 0.08%, an alkane content ≥ 60%. In the International System of Units, the unit of kinematic viscosity is the stokes, i.e. meters per second squared (m 2 / s); in practical measurements, centistokes (cSt) are often used, 1 cSt being equal to 1 mm 2 / s.

[0045] The composite mineral solvent oil of the preferred embodiment of the present application is composed of D40-D120 solvent oil, light oil, and specifically as follows:

[0046] D40 solvent oil 20-200 parts, preferably 20-100 parts;

[0047] D100 solvent oil 20-200 parts, preferably 50-90 parts;

[0048] D120 solvent oil 20-200 parts; preferably 20-80 parts;

[0049] Light oil 20-200 parts, preferably 20-50 parts.

[0050] In addition, the oil-based antifoaming agent includes 30-50 parts by weight of polyether-modified silicone oil. Preferably, the polyether-modified silicone oil is composed of non-ionic polyether-modified dimethyl silicone and polyether-epoxy co-modified silicone oil, and the weight ratio of the non-ionic polyether-modified dimethyl silicone and the polyether-epoxy co-modified silicone oil is 10-50:10-50. The non-ionic polyether-modified dimethyl silicone and the polyether-epoxy co-modified silicone oil in the embodiment of the present application are one or several of polyether macromolecules and epoxy alkane inserted into the chain segment of polymethylsiloxane macromolecule, and have the advantages of polymethylsiloxane, epoxy alkane and polyether.

[0051] Specifically, the polyether-modified silicone oil includes:

[0052] Non-ionic polyether-modified dimethyl silicone 10-50 parts;

[0053] Polyether-epoxy co-modified silicone oil 10-50 parts.

[0054] More specifically, the polyether-modified silicone oil includes:

[0055] Polyether-modified silicone oil component I, polyether-modified dimethyl silicone 0-50 parts, preferably 10 parts; HLB value 9.98, surface tension 23.5-24 mN / m, viscosity 500-900 mpa.s (25°C);

[0056] Polyether modified silicone oil component II, polyether modified polydimethylsiloxane 0-50 parts, preferably 10 parts; HLB value 4.9, surface tension 23.5-24 mN / m, viscosity 600-1200 mpa.s (25℃);

[0057] Polyether modified silicone oil component III, polyether modified polydimethylsiloxane 0-50 parts, preferably 10 parts; HLB value 9.58, surface tension 28.2 mN / m, viscosity 500-800 mpa.s (25℃);

[0058] Polyether modified silicone oil component IV, polyether modified polydimethylsiloxane 0-50 parts, preferably 10 parts; HLB value 9.35, surface tension 24 mN / m, viscosity 70-200 mpa.s (25℃);

[0059] Polyether modified silicone oil component V, polyether epoxy co-modified silicone oil 0-50 parts, preferably 10 parts; epoxy value 0.017-0.024 mol / 100g, viscosity 2500-3000 mpa.s (25℃).

[0060] HLB value (Hydrophile Lipophilic Balance): surfactants are amphiphilic molecules with hydrophilic groups and lipophilic groups, the size and strength balance degree between the hydrophilic group and the lipophilic group in the surfactant molecule, defined as the hydrophilic-lipophilic balance value of the surfactant, also known as water-oil degree.

[0061] Correspondingly, the oil-based defoamer manufacturing method provided by the embodiment of the present application comprises the following steps:

[0062] S1, mixing and reacting the organosiloxane, fumed silica and silane coupling agent, and optionally the methyl MQ silicone resin to obtain a composite organosilicon paste;

[0063] S2, mixing the composite organosilicon paste, surfactant, mineral solvent oil and polyether modified silicone oil according to the weight ratio, and stirring to obtain the oil-based defoamer for pulp black liquor.

[0064] Preferably, the step S1 comprises: mixing the organosiloxane, methyl MQ silicone resin, fumed silica and silane coupling agent, heating to 105℃-150℃ after adding the materials, keeping warm for 3-9 hours, and then pressurizing and vacuumizing to-0.08 MPa, and obtaining the composite organosilicon paste after 0.5-2.5 hours. The raw material content is as described above, and will not be repeated here.

[0065] Further preferably, the preparation method of the silicone paste is specifically:

[0066] ① 1000 kg of polydimethylsiloxane (silicone oil), 0-30 kg of methyl MQ silicone resin, start stirring at 50-100 rpm, electric heating to 150-200℃, and keep for 3-12 hours;

[0067] ② After adding no more than 60 kg of fumed silica, keep for 1-8 hours;

[0068] ③ Add 0-25 kg of dimethyldimethoxysilane and 0-25 kg of vinyl tributylketoxime silane mixture as coupling agent, after adding the material, heat to 105℃-150℃ (about 1-4 hours), and keep for 3-8 hours;

[0069] ④ After continuously heating to 150℃ under normal pressure (0.5-4 hours), pressurize and vacuumize to -0.08 MPa for about 1-4 hours;

[0070] ⑤ Keep at normal temperature and reduce pressure, break the vacuum, pass cooling water to reduce the temperature to below 60℃-80℃, and naturally cool to the discharge temperature, for a total of about 10-24 hours to obtain a silicone paste.

[0071] After adding the coupling agent in the embodiment of the present application, the silicone paste is obtained by high-temperature conversion, vacuumization and vacuum breaking, and temperature reduction and cooling. The preparation method of the oil-based defoaming agent for pulping black liquor in the embodiment of the present application can include the above steps of preparing the silicone paste, and further include: mixing 200-800 parts of the composite silicone paste, 50-100 parts of the composite surfactant, 100-650 parts of the composite mineral solvent oil, and 30-50 parts of the polyether modified silicone oil by weight, using a shearing stirrer (diameter ￠300-400 mm), a speed-regulating motor with a speed-regulating range of 0-1440 rpm (the actual stirring and shearing mixing speed is 500-800 rpm), and stirring for 20-30 minutes, to obtain the oil-based defoaming agent, which can be referred to as an oil-based cooking black liquor defoaming agent, a pulping cooking black liquor defoaming agent, an oil-based black liquor defoaming agent, and an oil-based pulping black liquor defoaming agent.

[0072] In the step S2, the stirring speed is 500-800 rpm, and the stirring time is 20-30 minutes, to obtain the oil-based defoaming agent. The stirrer parameters are as follows: a 15 kw ordinary explosion-proof variable frequency hydraulic lifting disperser; mainly including a motor power of 15 kw (pure copper explosion-proof motor), a hydraulic station of 1.1 kw pure copper explosion-proof motor, a lifting stroke of 1100 mm, a dispersing disc diameter of 300 mm, a dispersing shaft and a dispersing disc material of 304 stainless steel, and a rotating speed of 0-1440 revolutions / minute.

[0073] And, the application provides the application of the oil-based defoaming agent in the defoaming treatment of the cooking black liquor screening or washing. The application mode of the defoaming agent for the pulp cooking black liquor in the defoaming treatment of the black liquor is not specially limited in the application, and the application mode well known to those skilled in the art can be adopted. In the application, specifically in the pulp spraying washing process, the oil-based defoaming agent (0.08-0.20 kg / ADT of ton pulp, equivalent to 5-12 ppm) is added in the extraction of the cooking pulp black liquor (generally, the solid content of the black liquor is ≥15%, the water content is ≤85%, and the viscosity of the black liquor is generally 1-10 mpa.s) and the pulp washing machine section, and the black liquor level of the pulp washing machine and the filtrate tank is controlled through the defoaming and bubble suppressing treatment of the bubbles during the period, so as to improve and ensure the production capacity of the pulp washing machine and the washing cleanliness of the yellow pulp.

[0074] Through the test, the defoaming time of the oil-based defoaming agent for the cooking black liquor provided by some embodiments of the application is ≤2-3 seconds, and the bubble suppressing time is ≥240 seconds, the defoaming is fast, the bubble suppressing is persistent, and the amount is small when the defoaming treatment is performed on the cooking black liquor. BRIEF DESCRIPTION OF DRAWINGS

[0075] Figure 1 The defoaming operation and results in some embodiments of the application. DETAILED DESCRIPTION

[0076] In order for those skilled in the art to better understand the technical solutions of the application, the application will be described in detail below in combination with specific embodiments, and the description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the application.

[0077] In order to better understand the technical content of the application, specific embodiments are provided below to further illustrate the application. In the following embodiments, the mass ratio is used unless otherwise specified; the raw materials used are commercially available, and conventional equipment is adopted. The MQ silicone resin: M / Q = 0.70, active matter solid content: ≥99%, appearance: white particles or powder. Light oil density: 700-800 kg / m 3 , viscosity ≤10 cSt, volatile temperature ≤150℃, sulfur content ≤0.08%, and alkane content ≥60%. In addition, the solid content of the black liquor is generally ≥15%, the water content is ≤85%, and the viscosity of the black liquor is generally 1-10 mpa.s.

[0078] Embodiment 1

[0079] An oil-based defoaming agent for pulp black liquor, which comprises the following components in parts by weight: composite organic silicon paste 700-800 parts, composite surfactant 50-80 parts, composite mineral solvent oil 100-200 parts, and polyether modified silicone oil 40-50 parts.

[0080] 1) Composite organic silicon paste

[0081] In the present application, the weight fraction of 1000 parts of the silicone paste is taken as the basis, that is, the composite type machine silicone, fumed silica, dimethyl and vinyl composite type silane coupling agent are added in turn, and the mixture is reacted to obtain:

[0082] Organic siloxane (300 mpa.s) 100 parts;

[0083] Organic siloxane (500 mpa.s) 100 parts;

[0084] Organic siloxane (1000 mpa.s) 100 parts

[0085] Organic siloxane (2000 mpa.s) 565 parts;

[0086] Organic siloxane (5000 mpa.s) 50 parts;

[0087] Fumed silica (V15P, 150±20m 2 / g) 25 parts;

[0088] Fumed silica (N20P, 175-225m 2 / g) 25 parts;

[0089] Vinyl tributyl ketoxime silane 12.5 parts; dimethyl dimethoxysilane 12.5 parts; methyl MQ silicone resin 10 parts.

[0090] 2) Composite surfactant

[0091] In the present application, the weight fraction of the composite surfactant is preferably 80 parts. That is, the surfactant includes: triethanolamine oleic acid soap 25 parts; fatty alcohol polyoxyethylene ether sodium sulfate 15 parts; Span 80 (S-80) 20 parts; Tween 80 (T-80) 20 parts.

[0092] 3) Composite mineral solvent oil

[0093] In the present application, the weight fraction of the composite mineral solvent oil is 150 parts. That is, the composite mineral solvent oil is composed of one or a mixture of several of D40, D100, D120, light oil. Specifically: D40 solvent oil 20 parts; D100 solvent oil 90 parts; D120 solvent oil 20 parts; light oil 20 parts.

[0094] 4) Polyether modified silicone oil

[0095] In the present application, the weight fraction of the polyether modified silicone oil agent is 50 parts. That is, the polyether modified silicone oil includes: one or a mixture of several of non-ionic polyether modified polydimethylsiloxane and polyether epoxy co-modified silicone oil. Specifically as follows:

[0096] Polyether modified silicone oil component I, polyether modified polydimethylsiloxane is 10 parts; HLB value 9.98, surface tension 23.5-24 mN / m, viscosity 500-900 mpa.s (25°C);

[0097] Polyether modified silicone oil component II, polyether modified polydimethylsiloxane is 10 parts; HLB value 4.9, surface tension 23.5-24 mN / m, viscosity 600-1200 mpa.s (25°C);

[0098] Polyether modified silicone oil component III, polyether modified polydimethylsiloxane is 10 parts; HLB value 9.58, surface tension 28.2 mN / m, viscosity 500-800 mpa.s (25°C);

[0099] Polyether modified silicone oil component IV, polyether modified polydimethylsiloxane is 10 parts; HLB value 9.35, surface tension of the stock solution 24 mN / m, viscosity 70-200 mpa.s (25°C);

[0100] Polyether modified silicone oil component V, polyether epoxy co-modified silicone oil is 10 parts; epoxy value 0.017-0.024 mol / 100g, viscosity 2500-3000 mpa.s (25°C).

[0101] The preparation method of the oil-based black liquor defoaming agent comprises:

[0102] 1. preparing a silicone paste, and the preparation method of the silicone paste is specifically:

[0103] 1) take 1000 kg of polydimethylsiloxane (silicone oil), add 10 kg of methyl MQ silicone resin, start stirring at 50-100 rpm, and electrically heat to 150-200°C for 3-4 hours;

[0104] 2) after adding 50 kg of fumed silica, heat for 1-2 hours; stirring is continuously performed during the heating, and the stirring speed is 50-100 rpm;

[0105] 3) add 12.5 kg of dimethyldimethoxysilane and 12.5 kg of vinyl tributylketoxime silane mixture as a coupling agent, heat to 105-150°C (about 1-3 hours) after the addition of the material is completed, and heat for 3-4 hours; stirring is continuously performed during the heating, and the stirring speed is 50-100 rpm;

[0106] 4) Continue to atmospheric temperature to 150 ℃ (0.5 ~ 1 hour), the whole period of stirring, stirring speed 50 ~ 100 rpm; pressure vacuum ~ -0.08 MPa (about 1 ~ 2 hours; atmospheric pressure vacuum, cooling water to 60 ℃ (about 3 ~ 4 hours) 60 ℃ ~ 80 ℃ below, natural cooling to the discharge temperature, about 10 ~ 14 hours to get silicon paste.

[0107] 2, defoaming agent preparation (from the mixture of other defoaming agent auxiliary materials preparation): by weight parts, preferably 700 ~ 800 parts of composite silicone silicone paste (preferred components see above: "1) composite silicone silicone paste"), composite surfactant 50 ~ 80 parts (preferred components see above: "2) composite surfactant"), composite mineral solvent oil 100 ~ 200 parts (preferred components see above: "3) composite mineral solvent oil"), polyether modified silicone oil 40 ~ 50 parts mixture (preferred components see above: "4) polyether modified silicone oil"), in the shear mixer (diameter ￠ 300-400), speed motor speed range 650 ~ 1100 rpm, stirring time 20 ~ 30 minutes, prepared oil-based black liquor defoamer.

[0108] The mixer parameters are: 15kw ordinary explosion-proof variable frequency hydraulic lifting disperser; mainly including motor power of 15kw (pure copper explosion-proof motor), hydraulic station of 1.1kw pure copper explosion-proof motor, lifting stroke of 1100mm, dispersion disc diameter of 300mm, dispersion shaft and dispersion disc material of 304 stainless steel, rotation speed of 0 ~ 1440r / min.

[0109] Example 2

[0110] An oil-based pulp black liquor defoamer, by weight parts, including composite silicone silicone paste preferably 690 ~ 730 parts, composite surfactant 65 ~ 75 parts, composite mineral solvent oil 150 ~ 200 parts, polyether modified silicone oil 40 ~ 50 parts.

[0111] 1) composite silicone silicone paste

[0112] In the present application, with the weight parts of 1000 parts of the silicone paste as the basis, namely with the composite organosiloxane, fumed silica, dimethyl and vinyl composite silane coupling agent added in turn, prepared by mixing reaction:

[0113] Organosiloxane (300 mpa.s) 100 parts;

[0114] Organosiloxane (500 mpa.s) 100 parts;

[0115] Organosiloxane (1000 mpa.s) 100 parts

[0116] Organic siloxane (2000 mpa.s) 565 parts;

[0117] Organic siloxane (5000 mpa.s) 50 parts;

[0118] Fumed silica (V15P, 150 ± 20 m 2 / g) 25 parts;

[0119] Fumed silica (N20P, 175-225 m 2 / g) 25 parts;

[0120] Vinyl tributanone oxime silane 12.5 parts; dimethyl dimethoxy silane 12.5 parts; methyl MQ silicone resin 10 parts.

[0121] 2) Complex surfactant

[0122] In the present application, the complex surfactant is 70 parts by weight. That is, the surfactant includes one or a mixture of several of triethanolamine oleic soap, fatty alcohol polyoxyethylene ether sodium sulfate, Span 80, Tween 80. Including: triethanolamine oleic soap 25 parts; fatty alcohol polyoxyethylene ether sodium sulfate 15 parts; Span 80 (S-80) 15 parts; Tween 80 (T-80) 15 parts.

[0123] 3) Complex mineral solvent oil

[0124] In the present application, the complex mineral solvent oil is 175 parts by weight. That is, the complex mineral solvent oil is composed of one or a mixture of several of D40, D100, D120, light oil.

[0125] D40 solvent oil 20 parts; D100 solvent oil 110 parts; D120 solvent oil 20 parts; light oil 25 parts.

[0126] 4) Polyether modified silicone oil

[0127] In the present application, the polyether modified silicone oil is preferably 45 parts by weight. That is, the polyether modified silicone oil includes one or a mixture of several of non-ionic polyether modified polydimethylsiloxane and polyether epoxy co-modified silicone oil.

[0128] Polyether modified silicone oil component I, polyether modified polydimethylsiloxane 5 parts; HLB value 9.98, surface tension 23.5-24 mN / m, viscosity 500-900 mpa.s (25°C);

[0129] Polyether modified silicone oil component II, polyether modified polydimethylsiloxane 10 parts; HLB value 4.9, surface tension 23.5-24 mN / m, viscosity 600-1200 mpa.s (25°C);

[0130] Polyether modified silicone oil component III, polyether modified polydimethylsiloxane 10 parts; HLB value 9.58, surface tension 28.2 mN / m, viscosity 500-800 mpa.s (25°C);

[0131] Polyether modified silicone oil component IV, polyether modified polydimethylsiloxane 10 parts; HLB value 9.35, surface tension of the stock solution 24 mN / m, viscosity 70-200 mpa.s (25°C).

[0132] Polyether modified silicone oil component V, polyether epoxy co-modified silicone oil 10 parts; epoxy value 0.017-0.024 mol / 100g, viscosity 2500-3000 mpa.s (25°C).

[0133] The preparation method of the oil-based black liquor defoaming agent comprises:

[0134] 1. preparing a silicone paste, and the preparation method of the silicone paste is specifically:

[0135] 1) taking 1000 kg of polydimethylsiloxane (silicone oil), adding 10 kg of methyl MQ silicone resin, stirring at 50-100 rpm, and electrically heating to 150-200°C for 3-4 hours;

[0136] 2) adding 50 kg of white carbon black after 1-2 hours (hydrophobic or hydrophilic fumed silica, specific surface area 150±20 m 2 / g-200±20 m 2 / g);

[0137] 3) adding 12.5 kg of a mixture of dimethyldimethoxysilane and vinyl tributylketoximosilane as a coupling agent, heating to 105°C-150°C after the addition of the material (about 2-3 hours), and maintaining the temperature for 3-4 hours;

[0138] 4) continuing to heat to 150°C under normal pressure (0.5-1 hour), then pressurizing and vacuumizing to -0.08 MPa (about 1-2 hours; normal temperature and reduced pressure), breaking the vacuum, passing cooling water to reduce the temperature to 60°C (about 3-4 hours), and naturally cooling to the discharge temperature below 60°C-80°C, for a total of about 10-14 hours to obtain the silicone paste.

[0139] 2. Preparation of the defoaming agent, including the preparation of the above-mentioned defoaming agent main material self-made silicone paste and the mixture of the silicone paste and other defoaming agent auxiliary materials: by weight parts, preferably 690-730 parts of composite silicone silicone paste (preferred components are described above: "1) composite silicone silicone paste"), 65-75 parts of composite surfactant (preferred components are described above: "2) composite surfactant"), 150-200 parts of composite mineral solvent oil (preferred components are described above: "3) composite mineral solvent oil"), 40-50 parts of polyether modified silicone oil mixture (preferred components are described above: "4) polyether modified silicone oil"), in a shear mixer (diameter ￠300-400), the speed regulating motor speed regulating range is 650-1100 rpm, the stirring time is 20-30 minutes, and the oil-based black liquor defoaming agent is prepared.

[0140] The stirring machine parameters are: 15kw ordinary explosion-proof variable frequency hydraulic lifting dispersing machine. Mainly including motor power of 15kw (pure copper explosion-proof motor), hydraulic station of 1.1kw pure copper explosion-proof motor, lifting stroke of 1100mm, dispersing disc diameter of 300mm, dispersing shaft and dispersing disc material of 304 stainless steel, rotating speed of 0-1440r / min.

[0141] Example 3

[0142] An oil-based pulping black liquor defoaming agent, by weight parts, includes 750-800 parts of composite silicone silicone paste, 70-80 parts of composite surfactant, 100-130 parts of composite mineral solvent oil, and 30-40 parts of polyether modified silicone oil.

[0143] 1) Composite silicone silicone paste

[0144] In the present application, based on 1000 parts by weight of the silicone paste, i.e. the composite organosiloxane, fumed silica, dimethyl and vinyl composite silane coupling agent are sequentially added and mixed to obtain:

[0145] Organosiloxane (300 mpa.s) 100 parts;

[0146] Organosiloxane (500 mpa.s) 100 parts;

[0147] Organosiloxane (1000 mpa.s) 100 parts

[0148] Organosiloxane (2000 mpa.s) 565 parts;

[0149] Organosiloxane (5000 mpa.s) 50 parts;

[0150] Fumed silica (V15P, 150±20m 2 / g) 25 parts;

[0151] fumed silica (N20P, 175-225 m 2 / g) 25 parts;

[0152] vinyl tributanone oxime silane 12.5 parts; dimethyl dimethoxy silane 12.5 parts; methyl MQ silicone resin 10 parts.

[0153] 2) Complex surfactant

[0154] In the present application, the complex surfactant is 75 parts by weight. That is, the surfactant includes one or a mixture of several of triethanolamine oleic soap, fatty alcohol polyoxyethylene ether sodium sulfate, Span 80, Tween 80. It includes: triethanolamine oleic soap 25 parts; fatty alcohol polyoxyethylene ether sodium sulfate 20 parts; Span 80 (S-80) 15 parts; Tween 80 (T-80) 15 parts.

[0155] 3) Complex mineral solvent oil

[0156] In the present application, the complex mineral solvent oil is 115 parts by weight. That is, the complex mineral solvent oil is composed of one or a mixture of several of D40, D100, D120, light oil. D40 solvent oil 20 parts; D100 solvent oil 45 parts; D120 solvent oil 25 parts; light oil 2 25 parts.

[0157] 4) Polyether modified silicone oil

[0158] In the present application, the polyether modified silicone oil is 35 parts by weight. That is, the polyether modified silicone oil includes one or a mixture of several of non-ionic polyether modified polydimethylsiloxane and polyether epoxy co-modified silicone oil.

[0159] Polyether modified silicone oil component I, polyether modified polydimethylsiloxane 5 parts; HLB value 9.98, surface tension 23.5-24 mN / m, viscosity 500-900 mpa.s (25°C).

[0160] Polyether modified silicone oil component II, polyether modified polydimethylsiloxane 10 parts; HLB value 4.9, surface tension 23.5-24 mN / m, viscosity 600-1200 mpa.s (25°C).

[0161] Polyether modified silicone oil component III, polyether modified polydimethylsiloxane 5 parts; HLB value 9.58, surface tension 28.2 mN / m, viscosity 500-800 mpa.s (25°C).

[0162] Polyether modified silicone oil component IV, polyether modified polydimethylsiloxane 5 parts; HLB value 9.35, surface tension of the stock solution 24 mN / m, viscosity 70-200 mPa.s (25°C).

[0163] Polyether modified silicone oil component V, polyether epoxy co-modified silicone oil 10 parts; epoxy value 0.017-0.024 mol / 100g, viscosity 2500-3000 mPa.s (25°C).

[0164] The preparation method of the silicone paste comprises the following steps:

[0165] 1) Take 1000 kg of polydimethylsiloxane (silicone oil), add 10 kg of methyl MQ silicone resin, start stirring at 50-100 rpm, electric heating to 150-200°C, and keep for 3-4 hours;

[0166] 2) Add 50 kg of fumed silica (hydrophobic or hydrophilic fumed silica, specific surface area 150±20 m 2 / g-200±20 m 2 / g) after 1-2 hours;

[0167] 3) Add 12.5 kg of dimethyldimethoxysilane and 12.5 kg of vinyl tributylketoxime silane mixture as coupling agent, after the addition of the material, heat to 105°C-150°C (about 2-3 hours), and keep for 3-4 hours;

[0168] 4) Continue to heat to 150°C under normal pressure (0.5-1 hour), then add pressure and vacuum to -0.08 MPa (about 1-2 hours; normal temperature and reduced pressure), break the vacuum, pass cooling water to cool to 60°C (about 3-4 hours), and then naturally cool to the discharge temperature, about 10-14 hours in total to obtain the silicone paste.

[0169] The preparation method of the oil-based black liquor defoaming agent comprises the synthesis of the above-mentioned defoaming agent main material self-made silicone paste, and the mixing preparation of the defoaming agent auxiliary materials such as composite surfactant, composite mineral solvent oil, and composite polyether modified silicone oil.

[0170] Specifically, by weight parts, preferably composite silicone silicone paste 750-800 parts (preferred components see above: "1) composite silicone silicone paste"), composite surfactant 70-80 parts (preferred components see above: "2) composite surfactant"), composite mineral solvent oil 100-130 parts (preferred components see above: "3) composite mineral solvent oil"), polyether modified silicone oil 30-40 parts mixture (preferred components see above: "4) polyether modified silicone oil"), in the shear mixer (diameter ￠ 300-400), speed motor speed range 650-1100 rpm, stirring time 20-30 minutes, prepared oil-based black liquor defoamer.

[0171] The stirrer parameters are: 15kw ordinary explosion-proof variable frequency hydraulic lifting disperser; mainly including motor power of 15kw (pure copper explosion-proof motor), hydraulic station of 1.1kw pure copper explosion-proof motor, lifting stroke of 1100mm, dispersing disc diameter of 300mm, dispersing shaft and dispersing disc material of 304 stainless steel, rotating speed of 0-1440r / min.

[0172] Example 4

[0173] An oil-based pulping black liquor defoamer, by weight parts, including composite silicone silicone paste 780 parts, composite surfactant 80 parts, composite mineral solvent oil 100 parts, polyether modified silicone oil 40 parts.

[0174] 1) composite silicone silicone paste

[0175] In the present application, 1000 parts by weight of the silicone paste is taken as the basis, that is, the composite organosiloxane, fumed silica, dimethyl and vinyl composite silane coupling agent are sequentially added and mixed to obtain:

[0176] Organosiloxane (300 mpa.s) 100 parts;

[0177] Organosiloxane (500 mpa.s) 100 parts;

[0178] Organosiloxane (1000 mpa.s) 100 parts

[0179] Organosiloxane (2000 mpa.s) 565 parts;

[0180] Organosiloxane (5000 mpa.s) 50 parts;

[0181] Fumed silica (V15P, 150±20m 2 / g) 25 parts;

[0182] Fumed silica (N20P, 175-225m 2 / g) 25 parts;

[0183] Vinyl tributanone oxime silane 12.5 parts; dimethyl dimethoxy silane 12.5 parts; methyl MQ silicone resin 10 parts.

[0184] 2) Complex surfactant

[0185] In the present application, the complex surfactant is 80 parts by weight. That is, the surfactant includes one or a mixture of several of triethanolamine oleic soap, fatty alcohol polyoxyethylene ether sodium sulfate, Span 80, Tween 80. It includes: triethanolamine oleic soap 30 parts; fatty alcohol polyoxyethylene ether sodium sulfate 10 parts; Span 80 (S-80) 20 parts; Tween 80 (T-80) 20 parts.

[0186] 3) Complex mineral solvent oil

[0187] In the present application, the complex mineral solvent oil is 100 parts by weight. That is, the complex mineral solvent oil is composed of one or a mixture of several of D40, D100, D120, light oil. D40 solvent oil 20 parts; D100 solvent oil 40 parts; D120 solvent oil 20 parts; light oil 20 parts.

[0188] 4) Polyether modified silicone oil

[0189] In the present application, the polyether modified silicone oil is 40 parts by weight. That is, the polyether modified silicone oil includes one or a mixture of several of non-ionic polyether modified polydimethylsiloxane and polyether epoxy co-modified silicone oil.

[0190] Polyether modified silicone oil component I, polyether modified polydimethylsiloxane 5 parts; HLB value 9.98, surface tension 23.5-24 mN / m, viscosity 500-900 mpa.s (25°C);

[0191] Polyether modified silicone oil component II, polyether modified polydimethylsiloxane 10 parts; HLB value 4.9, surface tension 23.5-24 mN / m, viscosity 600-1200 mpa.s (25°C);

[0192] Polyether modified silicone oil component III, polyether modified polydimethylsiloxane 5 parts; HLB value 9.58, surface tension 28.2 mN / m, viscosity 500-800 mpa.s (25°C);

[0193] Polyether modified silicone oil component IV, polyether modified polydimethylsiloxane 10 parts; HLB value 9.35, surface tension of the original solution 24 mN / m, viscosity 70-200 mpa.s (25°C);

[0194] Polyether modified silicone oil component V, polyether epoxy co-modified silicone oil 10 parts; epoxy value 0.017-0.024 mol / 100g, viscosity 2500-3000 mpa.s (25℃).

[0195] The preparation method of the silicone paste is specifically as follows:

[0196] 1) Take 1000 kg of polydimethylsiloxane (silicone oil), add 10 kg of methyl MQ silicone resin, start stirring at 50-100 rpm, and electrically heat to 150-200℃ for 3-4 hours;

[0197] 2) After adding 50 kg of fumed silica, heat for 1-2 hours;

[0198] 3) Add 12.5 kg of dimethyldimethoxysilane and 12.5 kg of vinyl tributylketoxime silane mixture as a coupling agent, heat to 105℃-150℃ after the addition of the material (about 2-3 hours), and heat for 3-4 hours;

[0199] 4) Continue to heat to 150℃ under normal pressure (0.5-1 hour), then pressurize and vacuum to -0.08 MPa (about 1-2 hours; normal temperature and reduced pressure heat preservation), break the vacuum, pass cooling water to cool to 60℃ (about 3-4 hours), and naturally cool to the discharge temperature below 60℃-80℃, for a total of about 10-14 hours to obtain the silicone paste.

[0200] The preparation method of the oil-based black liquor defoamer includes the synthesis of the above-mentioned defoamer main material self-made silicone paste and the mixing preparation of the silicone paste and other defoamer auxiliary materials, and is specifically as follows:

[0201] By weight, preferably 780 parts of the composite silicone silicone paste (preferred components are described above: "1) Composite silicone silicone paste"), 80 parts of the composite surfactant (preferred components are described above: "2) Composite surfactant"), 100 parts of the composite mineral solvent oil (preferred components are described above: "3) Composite mineral solvent oil"), and 40 parts of the polyether modified silicone oil mixture (preferred components are described above: "4) Polyether modified silicone oil") are mixed in a shearing mixer (diameter ￠300-400), the speed of the speed-regulating motor is adjusted to 650-1100 rpm, and the stirring time is 20-30 minutes to prepare the oil-based black liquor defoamer.

[0202] The stirring machine parameters are as follows: 15 kw ordinary explosion-proof variable frequency hydraulic lifting dispersing machine; mainly including a motor power of 15 kw (pure copper explosion-proof motor), a hydraulic station of 1.1 kw pure copper explosion-proof motor, a lifting stroke of 1100 mm, a dispersing disc diameter of 300 mm, a dispersing shaft and a dispersing disc material of 304 stainless steel, and a rotating speed of 0-1440 revolutions / minute.

[0203] The oil-based pulp cooking black liquor defoaming agents of the embodiments 1, 2, 3 and 4 of the present application are subjected to performance testing, and compared with the oil-based defoaming agent pulp 352 of the Wacker defoaming agent and the oil-based defoaming agent commodity produced by a domestic manufacturer, and the specific steps are as follows:

[0204] The bleached kraft pulp cooking black liquor 400 mL is used as the foaming material, and the initial height of the black liquor column before foaming is 178 mm in a foaming glass column with a diameter of 54 mm. The foaming height is to 320 mm, and 0.5 mL of the oil-based pulp cooking black liquor defoaming agent (the defoaming agent is the oil-based pulp cooking black liquor defoaming agent of the embodiments 1-4 of the present application, the oil-based defoaming agent pulp 352 of the Wacker defoaming agent, etc.) is rapidly added within 0-1 second through the bubbling machine, and the time for the defoaming agent to eliminate the 140 mm height of the foam and the foam suppressing time are recorded. The results are shown in Table 1.

[0205] Table 1 Comparison results of the oil-based pulp cooking black liquor defoaming agents of the embodiments 1-4 with the commercially available commodities

[0206]

[0207] The black liquor without the addition of the defoaming agent is subjected to the circulating foaming, the liquid level of the black liquor containing the foam is to 320 mm to start as the 0 time, the foam is eliminated after the addition of the defoaming agent for about 3 seconds (3-7 seconds), and the liquid level is restored to the true liquid level 178 mm. The foam liquid level is gradually raised again with the circulating foaming of the black liquor, but the rising of the liquid level containing the foam is inhibited by the added defoaming agent, and slowly rises. During the period when the liquid level rises to a certain height, the total time of the period of the continuous generation and continuous destruction of the black liquor foam and the inhibition of the rising of the liquid level by the defoaming agent is called the foam suppressing time. For example, the foam suppressing time of the black liquor defoaming agent of the present application is 240 seconds (4 minutes) when the liquid level of the black liquor defoaming agent rises from 178 mm to a certain height, which is the examination standard: the defoaming agent with good defoaming effect and low relative foam is good in the foam suppressing performance.

[0208] According to Table 1, the defoaming time of the oil-based cooking black liquor defoaming agent of the present application is ≤2-3 seconds, and the foam suppressing time is ≥240 seconds. When the cooking black liquor is subjected to the defoaming treatment, the defoaming is fast, the foam suppressing is durable, and the amount is small. See Figure 1, left side of 178-180ml black liquor, add 0.1ML defoaming agent, bubble for about 3 minutes, the foam height can reach 320ML, after a few seconds, the foam is eliminated, as shown on the right side of the figure. The test results analyzed by the attached table can see that the oil-based type pulping and cooking black liquor defoaming agent provided by the application is faster in defoaming, longer in bubble suppression and less in dosage when defoaming and bubble suppressing the pulping and cooking black liquor, which is superior to the imported and domestic commercially available defoaming agent products. For example, the defoaming capacity data of Wacker silicone paste is 5 seconds, which is slightly worse than the defoaming agent 2-3 seconds of the application; other defoaming agents are not suitable for GFF pulp washer process or consume too much.

[0209] In the case of equivalent defoaming and bubble suppressing effect, the average dosage of the defoaming agent (0.05-0.10kg / ton of pulp, the mass of defoaming agent consumed for producing 1 ton of pulp, such as the corresponding daily output can be 1040 tons of pulp) is recorded. The results show that in the case of equivalent defoaming and bubble suppressing effect, the average dosage of the papermaking black liquor defoaming agent provided by the application is 0.05-0.10kg / ton of pulp, while the average dosage of the domestic and foreign competitive defoaming agent is 0.20-0.40kg / ton of pulp, the defoaming and bubble suppressing capacity of the competitive defoaming agent is poor, that is, the defoaming and bubble suppressing advantage of the application is 20-40mm lower than the liquid level of the competitive defoaming agent. It is shown that the defoaming and bubble suppressing capacity of the black liquor defoaming agent of the application is much stronger: the defoaming agent suppresses the foam capacity and the continuous bubble suppressing time is long, and the black liquor foam liquid level rising height is relatively lower than the competitive defoaming agent.

[0210] It should be noted that in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or device that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent to such a process, method, article or device.

[0211] The principles and implementation modes of the application are described by applying specific examples in this document, and the above examples are only used to help understand the method of the application and its core idea. The above description is only the preferred implementation mode of the application, and it should be pointed out that due to the limitedness of the expression, there are infinite specific structures, and for ordinary skilled persons in the technical field, some improvements, refinements or changes can be made without departing from the principle of the application, and the above technical features can also be combined in an appropriate way; these improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical scheme to other occasions without improvement, should be regarded as the protection scope of the application.

Claims

1. An oil-based antifoam agent for pulp black liquor, characterized by, The oil-based defoaming agent is prepared from the following components by weight: 200-800 parts of a composite organosilicon paste, 50-100 parts of a surfactant, 100-800 parts of a mineral solvent oil, and 30-50 parts of a polyether-modified silicone oil; the effective component of the oil-based defoaming agent has a water content of less than 0.5%. The composite organosilicon paste is prepared from organosiloxane, fumed silica, and silane coupling agent; the organosiloxane includes dimethyl silicone oil with a viscosity of 300-5000 mpa.s; the raw materials of the composite organosilicon paste further include methyl MQ silicone resin. The surfactant is selected from one or more of triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate, Span 80, and Tween 80. The mineral solvent oil includes D40-D120 solvent oil and / or light oil.

2. The oil-based antifoam agent according to claim 1, characterized by, In the raw materials of the composite organosilicon paste, the organosiloxane is composed of first, second, third, fourth, and fifth dimethyl silicone oils with viscosities of 300-400, 500-800, 900-1200, 1800-2100, and 3500-5000 mpa.s, respectively; the weight ratio of the first, second, third, fourth, and fifth dimethyl silicone oils is 20-200:20-200:20-200:20-600:20-200.

3. The oil-based antifoam agent according to claim 1, characterized by, The raw material of the composite silicone paste has a specific surface area of 130-230 m 2 / g.

4. The oil-based antifoam agent according to any one of claims 1 to 3, characterized in that, The weight ratio of the organosiloxane, fumed silica, silane coupling agent, and methyl MQ silicone resin is 100-1200:20-60:10-50:1-30. The silane coupling agent is vinyl tributylketoxime silane and / or dimethyl dimethoxysilane.

5. The oil-based antifoam agent according to claim 4, characterized by, The mineral solvent oil is composed of D40, D100, D120 solvent oils, and light oil; the weight ratio of the D40, D100, D120 solvent oils, and light oil is 20-300:20-300:20-300:20-200.

6. The oil-based antifoam agent according to claim 4, characterized by, The surfactant is composed of triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate, Span 80, and Tween 80; the weight ratio of the triethanolamine oleic acid soap, fatty alcohol polyoxyethylene ether sulfate, Span 80, and Tween 80 is 10-30:10-20:10-30:10-30.

7. The oil-based antifoam agent according to claim 4, characterized by, The polyether-modified silicone oil is composed of non-ionic polyether-modified polydimethylsiloxane and polyether-epoxy co-modified silicone oil; the weight ratio of the non-ionic polyether-modified polydimethylsiloxane and polyether-epoxy co-modified silicone oil is 10-50:10-50.

8. The method for preparing the oil-based defoaming agent according to any one of claims 1-7, comprising the following steps: S1, mixing organosiloxane, fumed silica, and silane coupling agent, and methyl MQ silicone resin, and then reacting to obtain a composite organosilicon paste. S2, the composite silicone paste, surfactant, mineral solvent oil and polyether modified silicone oil are mixed in a predetermined weight ratio, and stirred to obtain the oil-based antifoaming agent for pulping black liquor.

9. The production method according to claim 8, wherein The step S1 comprises: mixing organosiloxane, methyl MQ silicone resin, fumed silica and silane coupling agent, heating to 105℃-150℃ after feeding, and keeping for 3-9 hours, then pressurized vacuum to-0.08MPa, and keeping for 0.5-2.5 hours to obtain the composite silicone paste; The stirring speed in the step S2 is 500-800rpm, and the stirring time is 20-30 minutes to obtain the oil-based antifoaming agent.

10. The oil-based antifoaming agent according to any one of claims 1-7 for use in the defoaming treatment of cooking black liquor screening or washing.

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