阅读说明：本技术 一种反相增稠剂及其制备方法 (Reverse phase thickening agent and preparation method thereof ) 是由 阳习春 刘小林 叶武龙 蒋哲明 欧阳湘 易添福 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种反相增稠剂,包含混合丙烯酸类单体、乙烯基聚硅氧烷、非极性溶剂、中和剂、乳化剂、引发剂和水,所述混合丙烯酸类单体选自丙烯酸、丙烯酸酯、单羧基或者多羧基丙烯酰胺中的一种或多种；所述乙烯基聚硅氧烷包括单官能团或者双官能团的乙烯基聚硅氧烷。本发明一种反相增稠剂,通过乙烯基引入聚硅氧烷链段,使增稠剂除了形成广泛的氢键作用,还可以通过疏水硅氧烷链段与体系中疏水结构的强相容性,提高增稠效果。本发明一种反相增稠剂的制备方法,以烯丙基聚醚改性的环氧乳化剂作为主体乳化剂,配合超分子空腔化合物共同乳化,形成粒径低,稳定性好的乳液。(The invention discloses an inverse thickening agent, which comprises a mixed acrylic monomer, vinyl polysiloxane, a non-polar solvent, a neutralizing agent, an emulsifier, an initiator and water, wherein the mixed acrylic monomer is selected from one or more of acrylic acid, acrylate, and mono-carboxyl or multi-carboxyl acrylamide; the vinyl polysiloxane comprises monofunctional or difunctional vinyl polysiloxane. According to the reversed phase thickening agent, the polysiloxane chain segment is introduced through the vinyl group, so that the thickening agent not only can form a wide hydrogen bond effect, but also can improve the thickening effect through the strong compatibility of the hydrophobic siloxane chain segment and a hydrophobic structure in a system. The preparation method of the inverse thickener takes the allyl polyether modified epoxy emulsifier as a main emulsifier, and is matched with a supermolecule cavity compound for emulsification together to form emulsion with low particle size and good stability.)

1. The inverse thickener is characterized by comprising the following components in parts by weight:

the mixed acrylic monomer is selected from one or more of acrylic acid, acrylate, and single-carboxyl or multi-carboxyl acrylamide;

the vinyl polysiloxane comprises monofunctional or difunctional vinyl polysiloxane.

2. The inverse thickener of claim 1, wherein the mixed acrylic monomer is one or more of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobornyl ester, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and N, N' -methylenebisacrylamide.

3. The inverse thickener of claim 1, wherein the non-polar solvent is a hydrocarbon low molecular compound selected from one or more of kerosene, aromatic solvent oil, white mineral oil, gasoline and liquid paraffin.

4. The inverse thickener of claim 1, wherein the neutralizing agent is one or more of ammonia, dimethylethanolamine, ethanolamine, sodium hydroxide, and potassium hydroxide.

5. The inverse thickener of claim 1, wherein the emulsifier comprises a modified epoxy emulsifier, cucurbituril.

6. The inverse thickener of claim 5, wherein the modified epoxy emulsifier is prepared by the following process:

adding epoxy resin into a reaction kettle, heating to 80-120 ℃, stirring until the raw materials are completely dissolved, adding allyl polyether and Benzoyl Peroxide (BPO), continuously reacting for 2-10 hours, cooling to 40-100 ℃ after the reaction, adding water, and strongly dispersing for 1-5 hours to form semitransparent dispersion liquid.

7. The inverse thickener of claim 1, wherein the initiator is a water soluble initiator selected from one or more of ammonium sulfite, potassium persulfate, azobisisobutyronitrile, azobisisobutyrimidazoline hydrochloride.

8. The preparation method of the inverse thickening agent is characterized by comprising the following steps:

s1, oil phase preparation: adding vinyl polysiloxane and an emulsifier into a nonpolar solvent, filling nitrogen and stirring to obtain a stable and uniform oil phase solution;

s2, water phase preparation: uniformly mixing water and mixed acrylic monomers, adding a neutralizer for neutralization, and standing for later use;

s3, preparing an inverse emulsion: stirring the oil phase solution at a high speed, slowly dripping the water phase solution into the oil phase, and stirring at a constant speed for a preset time to obtain a stable inverse emulsion;

s4, polymerization reaction: and (3) after deoxidizing the inverse emulsion, adding an initiator into the reaction liquid, reacting at a set temperature, and cooling after the reaction is finished to obtain the inverse thickener.

9. The method for preparing an inverse thickener according to claim 8, wherein a neutralizing agent is added to neutralize the solution to a pH of 5 to 7 in step S2.

10. The preparation method of the inverse thickener according to claim 8, wherein in step S4, the inverse emulsion is continuously filled with nitrogen to remove oxygen in the system, the initiator is gradually and slowly added into the reaction solution, the reaction is carried out at 60-100 ℃ for 2-6 h, and the material is discharged when the temperature is reduced to below 20-50 ℃ after the reaction.

Technical Field

The invention belongs to the technical field of thickening agents, and particularly relates to an inverse thickening agent and a preparation method thereof.

Background

Depending on the type of polymer, thickeners can be broadly classified into three categories, including non-electrolyte polymers such as micro-crosslinked polyacrylamide and polyethylene glycol, polymer electrolytes such as micro-crosslinked polyacrylate salts, and micro-crosslinked copolymers of electrolyte monomers of acrylate salts and non-electrolyte monomers of acrylamide type. Thickeners are classified into four types, namely, powder type, W/O (water-in-oil) emulsion type, O/W (oil-in-water) emulsion type and dispersion type in which polymer fine particles are dispersed in an oil phase medium, according to their morphology. Among them, the polyamide system W/O type thickener is widely used due to its high thickening efficiency and high phase inversion speed.

The polyamide system W/O type thickener is mainly applied to the industries of printing and dyeing, cosmetics, coatings and the like, the inverse emulsion polymerization process is a dynamic control process mainly based on a micelle nucleation mechanism, and the product has wide particle size distribution and poor stability. In order to improve the particle size and stability of the product, more emulsifier is generally added into the formula. The normal phase emulsion polymerization usually adopts an ionic surfactant as an emulsifier, and long-chain hydrocarbon or long-chain fatty alcohol as an auxiliary stabilizer, so that an interface barrier is formed on the surface of the liquid drop, and the liquid drop is prevented from further approaching by virtue of electrostatic repulsion or steric hindrance. In the inverse emulsion polymerization, a nonionic surfactant with high lipophilicity is usually adopted as an emulsifier, and the composite type has a better effect than the singleness. The stability of the emulsion of the inverse polymerization polyamide W/O type thickener particle size control agent and the improvement of the phase inversion speed of the thickener in application are continuously improved tasks of the industry for a long time.

Therefore, the reactive monomer with a special structure is matched with the polyamide compound, and the emulsifier with a special function is adopted to improve the stability of the emulsion of the thickening agent, improve the thickening efficiency and accelerate the phase inversion speed of the emulsion, so that the method is a necessary condition for improving the application range of the thickening agent and is also a problem which is urgently needed to be solved by the industry.

Disclosure of Invention

The invention aims to provide an inverse thickener and a preparation method thereof, which are used for improving thickening efficiency, finished product stability and phase inversion speed.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides an inverse thickening agent, which comprises the following components in parts by weight:

the mixed acrylic monomer is selected from one or more of acrylic acid, acrylate, and single-carboxyl or multi-carboxyl acrylamide;

the vinyl polysiloxane comprises monofunctional or difunctional vinyl polysiloxane, and the viscosity range of the vinyl polysiloxane is 10-2000 cps.

In a preferred embodiment, the mixed acrylic monomer is one or more of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobornyl ester, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and N, N' -methylenebisacrylamide. In the actual selection process, the mixed acrylic monomer is preferably a mixture of a monofunctional monomer and a difunctional monomer.

Preferably, the non-polar solvent is a hydrocarbon low-molecular compound selected from one or more of kerosene, aromatic solvent oil, white mineral oil, gasoline and liquid paraffin. In practical application, the non-polar solvent is preferably white mineral oil.

In a preferred embodiment, the neutralizing agent is one or more of ammonia, dimethylethanolamine, ethanolamine, sodium hydroxide and potassium hydroxide.

Preferably, the neutralizing agent is added according to the neutralization degree of 80-110% of the amount of the carboxyl substance.

In a preferred scheme, the emulsifier comprises a modified epoxy emulsifier and cucurbituril (a supramolecular cavity compound), wherein the cucurbituril is a mixture of 6,7 and 8-membered cucurbituril;

the preparation process of the modified epoxy emulsifier comprises the following steps:

adding epoxy resin into a reaction kettle, heating to 80-120 ℃, stirring until the raw materials are completely dissolved, adding allyl polyether and Benzoyl Peroxide (BPO), continuously reacting for 2-10 hours, cooling to 40-100 ℃ after the reaction, adding water, and strongly dispersing for 1-5 hours to form semitransparent dispersion liquid.

In a preferred embodiment, the initiator is a water-soluble initiator selected from one or more of ammonium sulfite, potassium persulfate, azobisisobutyronitrile and azobisisobutyrimidazoline hydrochloride.

The invention also provides a preparation method of the inverse thickening agent, which comprises the following steps:

s1, oil phase preparation: adding vinyl polysiloxane and an emulsifier into a nonpolar solvent, filling nitrogen and stirring to obtain a stable and uniform oil phase solution;

s2, water phase preparation: uniformly mixing water and mixed acrylic monomers, adding a neutralizer for neutralization, and standing for later use;

s3, preparing an inverse emulsion: stirring the oil phase solution at a high speed, slowly dripping the water phase solution into the oil phase, and stirring at a constant speed for a preset time to obtain a stable inverse emulsion;

s4, polymerization reaction: and (3) after deoxidizing the inverse emulsion, adding an initiator into the reaction liquid, reacting at a set temperature, and cooling after the reaction is finished to obtain the inverse thickener.

Further, in step S2, a neutralizing agent is added to neutralize the solution to a pH of 5-7.

Further, in step S4, continuously filling nitrogen into the inverse emulsion to remove oxygen in the system, adding the initiator into the reaction solution in a graded and slow manner, reacting for 2-6 h at the temperature of 60-100 ℃, and discharging when the temperature is reduced to below 20-50 ℃ after the reaction is finished.

The principle of the invention is as follows: according to the invention, a reactive polysiloxane compound is adopted to modify a polyacrylamide macromolecular chain structure, so that the compatibility of the thickening agent with a main resin in an application process is improved, the thickening efficiency is increased, and the stability of a finished product is improved; meanwhile, the invention adopts hydrophilic modified epoxy as a main emulsifier, and compounds a supermolecule cavity compound (cucurbituril) with a hydrophilic outer cavity and a hydrophobic inner cavity as a phase inversion emulsifier, so that the phase inversion speed of the thickener emulsion in application is improved.

The beneficial technical effects of the invention are as follows:

according to the reversed phase thickening agent, the polysiloxane chain segment is introduced through the vinyl group, so that the thickening agent not only can form a wide hydrogen bond effect, but also can improve the thickening effect through the strong compatibility of the hydrophobic siloxane chain segment and a hydrophobic structure in a system.

The preparation method of the inverse thickener takes the allyl polyether modified epoxy emulsifier as a main emulsifier, and is matched with a supermolecule cavity compound for emulsification together to form emulsion with low particle size and good stability.

Detailed Description

In this example, unless otherwise specified, all reagents used were common commercial products or prepared by conventional means, and the equipment used was conventional in the art, and the following are some examples of the inventors in the experiment:

preparing a modified epoxy emulsifier:

adding 100kg of epoxy resin E20 into a reaction kettle, heating to 110 ℃, adding 50kg of allyl polyether, adding 1kg of BPO in batches, continuously reacting for 5h, cooling to 90 ℃ after the reaction is finished, slowly adding 50kg of water, strongly dispersing for 2h, and discharging when the temperature is lower than 40 ℃.

Example 1

The invention relates to a preparation method of an inverse thickening agent, which comprises the following steps:

s1, oil phase preparation: adding 200kg of white mineral oil, 10kg of vinyl polysiloxane with the viscosity of 10cps, 5 parts of modified epoxy emulsifier and 5 parts of cucurbituril into a reaction kettle, filling nitrogen and stirring for 30min to obtain a stable and uniform oil phase solution;

s2, water phase preparation: adding 200kg of water, 300kg of acrylic acid, 500kg of acrylamide and 10kg of N, N' -methylene bisacrylamide into the same container, neutralizing the solution with ammonia water until the pH value is 6, and standing the obtained solution for later use;

s3, preparing an inverse emulsion: stirring the oil phase solution at a high speed, slowly dripping the water phase solution into the oil phase, and stirring at a constant speed for a period of time to obtain a stable inverse emulsion;

s4, polymerization reaction: continuously filling nitrogen to remove oxygen in the system, gradually adding 1kg of ammonium persulfate initiator into the reaction solution in batches, reacting for 4 hours at the temperature of 80 ℃, and discharging when the temperature is reduced to below 40 ℃ after the reaction is finished.

Example 2

The invention relates to a preparation method of an inverse thickening agent, which comprises the following steps:

s1, oil phase preparation: adding 200kg of white mineral oil, 20kg of vinyl polysiloxane with the viscosity of 10cps, 5 parts of modified epoxy emulsifier and 5 parts of cucurbituril into a reaction kettle, filling nitrogen and stirring for 30min to obtain a stable and uniform oil phase solution;

s2, water phase preparation: adding 200kg of water, 300kg of acrylic acid, 500kg of acrylamide and 10kg of N, N' -methylene bisacrylamide into the same container, neutralizing the solution with ammonia water until the pH value is 6, and standing the obtained solution for later use;

s3, preparing an inverse emulsion: stirring the oil phase solution at a high speed, slowly dripping the water phase solution into the oil phase, and stirring at a constant speed for a period of time to obtain a stable inverse emulsion;

s4, polymerization reaction: continuously filling nitrogen to remove oxygen in the system, gradually adding 1kg of excessive ammonium acid initiator into the reaction solution, reacting at 80 deg.C for 4h, and cooling to below 40 deg.C.

Example 3

The invention relates to a preparation method of an inverse thickening agent, which comprises the following steps:

s1, oil phase preparation: adding 200kg of white mineral oil, 20kg of vinyl polysiloxane with the viscosity of 10cps and 5kg of modified epoxy emulsifier into a reaction kettle, filling nitrogen and stirring for 30min to obtain a stable and uniform oil phase solution;

s2, water phase preparation: adding 200kg of water, 300kg of acrylic acid, 500kg of acrylamide and 10kg of N, N' -methylene bisacrylamide into the same container, neutralizing the solution with ammonia water until the pH value is 6, and standing the obtained solution for later use;

s3, preparing an inverse emulsion: stirring the oil phase solution at a high speed, slowly dripping the water phase solution into the oil phase, and stirring at a constant speed for a period of time to obtain a stable inverse emulsion;

s4, polymerization reaction: continuously filling nitrogen to remove oxygen in the system, slowly adding 1kg of ammonium persulfate into the reaction solution in batches, keeping the temperature at 80 ℃ for reaction for 4h, and discharging when the temperature is reduced to below 40 ℃ after the reaction is finished.

Example 4

The invention relates to a preparation method of an inverse thickening agent, which comprises the following steps:

s1, oil phase preparation: adding 200kg of white mineral oil, 5kg of modified epoxy emulsifier and 5kg of cucurbituril into a reaction kettle, filling nitrogen and stirring for 30min to obtain a stable and uniform oil phase solution;

s2, water phase preparation: adding 200kg of water, 300kg of acrylic acid, 500kg of acrylamide and 10kg of NN methylene bisacrylamide into the same container, neutralizing the solution with ammonia water until the pH value is 6, and standing the obtained solution for later use;

s3, preparing an inverse emulsion: stirring the oil phase solution at a high speed, slowly dripping the water phase solution into the oil phase, and stirring at a constant speed for a period of time to obtain a stable inverse emulsion;

s4, polymerization reaction: continuously filling nitrogen to remove oxygen in the system, slowly adding 1kg of ammonium persulfate into the reaction solution in batches, keeping the temperature at 80 ℃ for reaction for 4h, and discharging when the temperature is reduced to below 40 ℃ after the reaction is finished.

And (3) performance testing: the stability, phase inversion time and viscosity at 1% solid content of the thickener sample emulsion are compared and tested

And (3) emulsion stability test: the sample is placed in a 50 ℃ oven and is placed for 24h, then whether the emulsion is layered or not is checked, and the layering degree of the emulsion is compared. The stability of the emulsion is judged according to the above, and the stability of the emulsion is characterized by an R value, wherein the closer the R value is to 1, the more stable the emulsion is.

R＝V/V₀

Wherein V represents the volume of the emulsion layer after standing for 24h, and V₀Indicating the volume of the emulsion layer at the beginning.

And (3) testing the phase inversion time of the emulsion: adding the emulsion into water according to the solid content of 1%, starting stirring, testing the viscosity at intervals of 10s until the viscosity does not change along with the stirring time, and recording the final viscosity. The shorter the time required for the emulsion viscosity to stabilize indicates a faster phase inversion, and the higher the final viscosity indicates a better thickening effect. Wherein T represents the phase inversion time, and N represents the 1% solid content viscosity.

TABLE 1 comparison of Performance test results for inverse thickeners of examples 1-4

Test items	Example 1	Example 2	Example 3	Example 4
					R	0.95	0.9	0.8	0.5
T(s)	10	10	40	20
					N(mPa.s)	12000	10000	8500	6800

As shown in Table 1, the silicone and cucurbituril were added simultaneously in example 1, and the stability, phase inversion time and thickening performance were all good. Example 2 the thickening efficiency becomes lower by reducing the amount of polysiloxane chain added; in the embodiment 3, after the cucurbituril is removed, the emulsion stability is good, and the phase inversion time is long; example 4 in which the polysiloxane was eliminated, the emulsion stability was poor and the thickening effect was poor. In conclusion, cucurbiturils greatly help to improve the phase inversion speed of the emulsion, and polysiloxanes greatly help to the stability and thickening efficiency of the emulsion. Therefore, the reverse phase thickening agent prepared by the invention has high thickening efficiency, high reverse phase speed and good stability.

Application example 1

The thickener prepared in example 1 (model number is LINTEC TP-1803) is used for preparing vinyl acetate-ethylene copolymer emulsion, and the specific formula is as follows:

the process flow comprises the following steps:

1. adding the VAE emulsion and water, starting stirring, and stirring at a low speed for 1-3 min;

2. slowly adding the thickening agent, properly increasing the rotating speed, and stirring for 10 min;

3. the 3 sets of viscosity data were tested in parallel and averaged.

Application example 2

The thickener prepared in example 1 (model number is LINTEC TP-1803) is used for preparing vinyl acetate-ethylene copolymer emulsion, and the specific formula is as follows:

the process flow comprises the following steps:

1. adding water, starting stirring;

2. slowly adding a thickening agent LINTEC TP-1803, properly increasing the rotating speed, and stirring at a high speed for 3-5 min;

3. reducing the rotating speed, slowly adding the VAE emulsion, and stirring for 3-5 min;

4. the 3 sets of viscosity data were tested in parallel and averaged.

Table 2 comparison of Performance test results of application examples 1-2

Test items	Application example 1(cps)	Application example 2(cps)
			First group	176500	35600
Second group	184600	36500
			Third group	173400	35800
Mean value of	178166.7	35966.7

As can be seen from Table 2, the application example 1 is an acidic environment, the thickening effect is extremely high, and 3 groups of parallel test data are stable and have good storage effect; the application example 2 is a neutral environment, the thickening effect is extremely high, and 3 groups of parallel data are stable and have good storage effect. The application examples prove that the reverse phase thickening agent has high thickening efficiency under different environments and good stability in a system.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.