JP2684710B2 - Water-in-oil polymer emulsion - Google Patents

Description

The present invention relates to a coagulant, a coagulant, a papermaking chemical, a petroleum tertiary recovery agent, an admixture for civil engineering and building materials, a mud conditioner, a thickener, an adhesive, a paint, The present invention relates to a stable water-in-oil emulsion that can be used for rubber, moisture-absorptive composite materials, and the like.

2. Description of the Related Art A method called a reverse phase polymerization method is widely known as a method for producing a water-in-oil emulsion. For example, Japanese Patent Publication 52-
39417 shows a water-in-oil emulsion consisting of a polymer, water, a hydrophobic liquid and a water-in-oil emulsifier.

Further, also regarding the method of removing water from the water-in-oil type polymer particles by azeotropic distillation, for example, in US Patent No. 4052353 and British Patent No. 1499731, a method for producing a dispersion of substantially anhydrous polymer particles in a non-aqueous liquid. Is disclosed.

[Problems to be Solved by the Invention] Many water-in-oil emulsions have hitherto been commercialized mainly because of their good handling properties.

However, there have been problems such as difficulty in sedimentation and separation of polymer particles during storage and redispersion due to mutual fusion of precipitated polymer particles.

Further, the water contained in the polymer particles in the conventional water-in-oil emulsion causes a decrease in the active ingredient of the polymer in the emulsion, which causes a problem in economy.

Further, if water is present in the polymer particles in an amount of more than 15% by weight, the polymer particles lack compatibility with various organic solvents, rubbers, synthetic resins and the like, and it is very difficult to mix or knead them.

Further, when azeotropic dehydration is carried out by a known method from a water-in-oil emulsion containing water-containing polymer particles, the polymer particles must be kept in a stable liquid state without coagulating with each other.

Furthermore, the dehydrated polymer particles have a larger specific gravity than the hydropolymer particles, so that the specific gravity difference with the organic dispersion medium is further increased, and the polymer particles tend to settle and separate during long-term storage. Becomes stronger.

Further, the precipitated and separated polymer particles often coagulate strongly, so that they are not easily re-dispersed even if some mechanical force is applied, and it is difficult to obtain a satisfactory emulsion.

Furthermore, when various dispersion stabilizers are used to improve the above-mentioned stability, even if the stability is improved, demulsification is often inhibited at the same time, which is a serious obstacle in use depending on the application. Emulsions are characterized by good dispersibility and dispersion, and must not be difficult to demulsify.

The present invention solves the above problems, and particularly provides a water-in-oil polymer emulsion having good emulsion dispersion stability, easy demulsification, and excellent miscibility with other resins and drugs. To do.

Means for Solving the Problems The present invention provides a water-in-oil type heavy polymer in which an aqueous phase containing a polymer obtained by polymerizing one or more water-soluble vinyl monomers is dispersed in an organic dispersion medium. A water-in-oil type polymer emulsion, characterized in that the combined emulsion contains at least 0.1% by weight of an amphoteric surfactant represented by the following general formula (1) with respect to the total weight of the emulsion.

(However, R and R'represent a saturated or unsaturated hydrocarbon group having 8 to 20 carbon atoms and may be the same or different.
m and n represent an integer of 1 to 10 and may be the same or different. X represents a halogen atom. ) Action The present invention, when emulsion-polymerizing a water-in-oil emulsion, the presence of at least 0.1% by weight of the specific amphoteric surfactant, based on the total weight of the emulsion, is stable during the polymerization, and is conventionally known. It has been completed by discovering that surfactants do not coagulate and coagulate even in the dehydration step where the probability of coagulation and coagulation of particles is high, and that the sedimentation and separability of polymer particles during long-term storage is dramatically improved. .

It has two long chain aliphatic groups, which are characteristic of amphoteric surfactants, which penetrates well into the oil phase and, on the other hand,
It has a quaternary ammonium group having strong polarity and a phosphoric acid group, which is considered to penetrate deeply into the aqueous phase and hold the interface between the two very stable.

Further, the water-in-oil type polymer emulsion using the amphoteric surfactant is very easy to demulsify, and is a major feature together with the stability of the emulsion.

 The present invention will be described in more detail below.

The present invention contains an amphoteric surfactant represented by the general formula (1) as an essential component for obtaining a stable water-in-oil polymer emulsion.

R and R'in the general formula (1) are saturated or unsaturated hydrocarbon groups having 8 to 20 carbon atoms, specifically, octyl, nonyl, decyl, lauryl, myristyl, cetyl,
Typical examples are stearyl and oleyl groups, and in addition to straight chains, branched alkyl groups can also be used. Further, m and n are integers from 1 to 10, but in particular m is 1 to 5 and n is 2
9 is preferred. X is a halogen atom, chlorine, bromine,
It is selected from iodine and fluorine.

This amphoteric surfactant can be synthesized by various methods, and there are no particular restrictions on the starting material, production route, kind of intermediate, and the like.

The amount used is 0.1% by weight or more, usually 0.2 to 1.5% by weight, based on the total weight of the marshon. If it is less than 0.1% by weight, a stable emulsion cannot be obtained. If the amount exceeds 1.5% by weight and is too large, a large amount of hydrophilic surfactant is required for demulsification, which is economically disadvantageous. Further, a known hydrophobic surfactant may be used together.

As the water-soluble vinyl monomer that constitutes the polymer,
(1) Nonionic vinyl monomer, (2) anionic vinyl monomer and (3) cationic vinyl monomer are used.

(1) Examples of the nonionic vinyl monomer include (meth) acrylamide (which means acrylamide or methacrylamide; the same applies hereinafter), vinyl methyl ether, vinyl ethyl ether, vinyl pyrrolidone, etc., and (2) anionic vinyl monomer As the body, (meth) acrylic acid, 2
-Acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, itaconic acid, maleic acid, fumaric acid, arylsulfonic acid or salts thereof, and the like, (3) as the cationic vinyl monomer, Neutralized salts or quaternary compounds of dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminomethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide, etc. Such as a neutralized salt or quaternized product of dialkylaminoalkyl (meth) acrylamide and the like.

The polymer particles in the water-in-oil emulsion are obtained by polymerizing one or more of the above.

When the polymer is linear, it is generally water-soluble, and a water-swellable polymer can be obtained by incorporating a crosslinkable monomer into the monomer and polymerizing it. Whether to obtain a water-soluble substance or a water-swellable substance is determined depending on the purpose of use.

The crosslinkable monomer is one that is copolymerizable with a water-soluble vinyl monomer, and includes, for example, N, N′-methylenebis (meth) acrylamide, divinylbenzene, (meth)
Examples thereof include divinyl compounds such as vinyl acrylate, vinyl methylol compounds such as methylol (meth) acrylamide, vinyl aldehyde compounds such as acrolein, and methyl acrylamide glycolate methyl ether, and the addition amount thereof can be arbitrarily changed depending on the purpose of use.

For example, the addition amount of the water-absorbent resin is about 0.02 to 1.0% by weight based on the weight of the monomer, and the addition amount of the useful coagulant is about 0.001 to 0.01% by weight based on the weight of the monomer.

The organic dispersion medium is an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, an oil, a chlorinated hydrocarbon, a fatty acid glyceride, or an aromatic ester such as dibutyl phthalate or dioctyl phthalate or a higher aliphatic ester,
Etc. are selected from solvents that can be used for reverse phase polymerization, and are used alone or in combination.

The concentration of the water-soluble vinyl monomer used during polymerization is usually 20 to 70% by weight, preferably 30 to 60% by weight, based on the weight of the aqueous solution, and the aqueous phase in the water-in-oil type polymer emulsion and the organic dispersion medium. The weight ratio of and can vary depending on the aqueous phase 1 to 5 with respect to the organic dispersion medium 1, but is usually preferably 2 to 4.

The water-in-oil emulsion of the present invention is produced, for example, as follows.

First, amphoteric surfactants and hydrophobic surfactants commonly used in reverse phase polymerization, such as sorbitan monostearate, sorbitan monooleate, and glyceryl monooleate.
In an organic dispersion medium containing and in a weight ratio of 1:99 to 100: 0, preferably 5:95 to 100: 0, an aqueous solution containing a water-soluble vinyl monomer is added, and a known method such as mechanical stirring is used. Emulsify by the emulsification method.

Then, the water-soluble vinyl monomer is polymerized, and the polymerization is initiated by a conventional method such as light, redox or thermal decomposition catalyst. The polymerization temperature is not particularly limited under normal pressure, but is usually 20.
-100 ° C, preferably 30-80 ° C.

When dehydration is performed after the polymerization, water and other volatile components are removed from the obtained emulsion by a known dehydration method. Specifically, usually under reduced pressure of 100 to 40 mmHg, 40 to 100 ° C
Is dehydrated in. The water content of the polymer particles after the dehydration step is less than 15% by weight based on the weight of the polymer particles, and the polymer particles are substantially anhydrous polymer particles. The ratio of the polymer particles after dehydration to the emulsion can be 70% by weight or more based on the total weight of the emulsion.

Usually, the polymer content of the water-in-oil type water-containing polymer emulsion obtained by polymerization using a water-soluble vinyl monomer aqueous solution which is industrially available is less than 45% by weight based on the total weight of the emulsion. By dehydration and concentration as described above, a high-concentration emulsion having the required concentration and characteristics can be obtained. Since the high-concentration emulsion has a small content of water having a large polarity, it is excellent in miscibility with various resins, and the transportation cost per polymer unit can be greatly reduced, thereby having a large economic effect.

The finally obtained emulsion exists in a water-in-oil type and can be used as it is depending on the application. However, in many cases, the resulting polymer comprising a water-in-oil emulsion is dispersed in a large amount of water to dissolve or swell,
It must be in a state where it can contact with water and absorb moisture. Addition of a hydrophilic surfactant is effective for that purpose, and the addition amount thereof is usually 0.5 with respect to the total weight of the emulsion.
-7 wt%, preferably 2-5 wt%.

EXAMPLES Hereinafter, the present invention will be described more specifically based on Production Examples (production of amphoteric surfactant) and Examples.

Production Example 1 20.0 g (0.136 mol) of glutamic acid was added to 600 ml of toluene.
In water, and 80.9 g (0.299 mol) of stearyl alcohol and 25.4 g (0.13 g) of p-toluenesulfonic acid (monohydrate)
Mol) was added thereto, and a Dien-Staak separator was attached, the reaction was carried out under reflux for 4 hours with stirring, and the generated water was removed from the system. After the completion of the reaction, the toluene solution is cooled and then washed with water,
After drying over sodium sulfate, toluene was distilled off to obtain a solid, which was further recrystallized from ethanol to obtain 100.7 g of a colorless p-toluenesulfonic acid salt of distearyl glutamate (yield 90.1%, mp72 0.0-73.0 ° C).

P- of the distearyl glutamate obtained as described above
Dissolve 59.4 g (0.072 mol) of toluenesulfonate in 500 ml of tetrahydrofuran (THF) in a flask,
Cooled and kept at 0 ° C. 9.8 g (0.087 mol) of chloroacetic acid chloride and 8.0 g (0.079 mol) of triethylamine dissolved in 50 cc of THF were added dropwise to the stirred flasks, and the mixture was stirred at 0 ° C. for 1 hour and further stirred at room temperature for 6 hours. did. Thereafter, THF was distilled off, the residue was dissolved in chloroform, washed with water, dried over magnesium sulfate, and dissolved by heating in n-hexane. Insolubles were filtered off and recrystallized to obtain colorless crystals.

The obtained crystals were dissolved in 500 ml of THF in a flask,
After adding 7.7 g (0.086 mol) of N, N-dimethylaminoethanol, the mixture was reacted under reflux for 8 hours. After completion of the reaction, the mixture was cooled to room temperature, THF was distilled off, and the residue was recrystallized from ethyl acetate to obtain 49 g of a compound corresponding to the above (yield: 83.1%, mp7
8.0-79.0 ° C).

45.7 g (0.0559 mol) of the compound corresponding to the above was dissolved in 500 ml of THF in a flask, 5.7 g (0.056 mol) of triethylamine was further added, and the mixture was ice-cooled. 8.6 g (0.056 mol) of phosphorus oxychloride was added from the dropping funnel over 1 hour,
Stir drop-wise in an ice-cooled flask and add 100 ml of ice water.
Was added and stirred. After the reaction was completed, THF was distilled off, the remaining aqueous layer was extracted with chloroform, magnesium sulfate was added to the chloroform layer and the mixture was left for half a day, chloroform was distilled off, and the resulting residue was further washed with acetone. Recrystallization gave 28 g (yield 54.2%) of the desired colorless solid.

The colorless solid obtained has melting point, elemental analysis, IR and NM.
It was confirmed to have the structure by R analysis.

The resulting compound is a quaternary ammonium salt-bound monoester of glutamic acid distearyl ester, which will be referred to as 2C ₁₈ GEQAPA for convenience.

Production Example 2 In Production Example 1, instead of chloroacetic acid chloride,
Except that undecanoic acid and dicyclohexylcarbodiimide were used, the same operation was carried out to obtain an amphoteric surfactant.
This was confirmed to have the following structure by elemental analysis, IR and NMR spectra.

The resulting amphoteric surfactant of the above formula will be denoted as 2C ₁₈ GEC ₁₀ QAC ₂ PA.

Production Example 3 In Production Example 2, instead of stearyl alcohol,
Except that cetyl alcohol was used, the same procedure was carried out to obtain an amphoteric surfactant. This was confirmed by elemental analysis, IR and NMR spectra, and was confirmed to have the following structure.

The resulting amphoteric surfactant of the above formula will be denoted as 2C ₁₆ GEC ₁₀ QAC ₂ PA.

Production Example 4 An amphoteric surfactant was obtained in exactly the same manner as in Production Example 1 except that 6-N, N-dimethylamino n-hexanol was used instead of N, N-dimethylaminoethanol. This was confirmed by elemental analysis, IR and NMR spectra, and was confirmed to have the following structure.

The obtained amphoteric surfactant of the above formula will be denoted as 2C ₁₈ GEC ₁ QAC ₆ PA.

Production Example 5 An amphoteric surfactant was obtained in exactly the same manner as in Production Example 2, except that 6-N, N-dimethylamino n-hexanol was used instead of N, N-dimethylaminoethanol. This was confirmed by elemental analysis, IR and NMR spectra, and as a result, it was confirmed that it had the following structure.

The obtained amphoteric surfactant of the above formula will be denoted as 2C ₁₈ GEC ₁₀ QAC ₆ PA.

Example 1 Boiling Range Containing 2.0 g of Amphoteric Surfactant Obtained in Production Example 15
250g of aliphatic hydrocarbon solvent at 8 to 177 ° C, 114.1g of sodium acrylate, 200g of acrylamide and t-BHP (t
-Butyl hydroperoxide) 0.03 g in aqueous solution 7
50 g was added and emulsified with a homogenizer.

The emulsion was transferred to a three-necked flask, degassed with N ₂ gas, an aqueous solution of sodium metabisulfite was added dropwise, and polymerization was carried out at a polymerization temperature of 40 ° C. for 3 hours.

After the completion of polymerization, after cooling to 40 ℃, boiling point range 200 ~ 230 ℃
125g of aliphatic hydrocarbon solvent is added, and the temperature is 40 ~ 80 ℃, 80 ~
Azeotropic distillation is performed under a reduced pressure of 40 mmHg, and after 7 hours 419 g of water
And 245 g of an aliphatic hydrocarbon solvent having a boiling point range of 158 to 177 ° C. were distilled off.

The obtained emulsion was a stable emulsion having a polymer concentration of 67.9% and a water content in the polymer of 5.3%.

Example 2 Boiling point range containing 1.7 g of the amphoteric surfactant obtained in Production Example 20
An aqueous solution containing 235 g of an aliphatic hydrocarbon solvent at 0 to 230 ° C., 241 g of acrylic acid having a neutralization degree of 80 mol with NaOH, 241 g, N, N′-methylenebisacrylamide 0.12 g and t-BHP 0.012 g.
Was added and emulsified with a homogenizer. The emulsion was transferred to a three-necked flask, degassed with N ₂ gas, an aqueous solution of sodium metabisulfite was added dropwise, and polymerization was carried out at a polymerization temperature of 60 ° C. for 2 hours.

After the completion of polymerization, cool it to 40 ℃,
Vacuum distillation was performed under reduced pressure of -40 mmHg, and after 4 hours, 343 g of water was distilled off, and the polymer concentration was 53.9% and the water content in the polymer was 7.2.
% Stable water-in-oil emulsion was obtained.

Example 3 Boiling point range containing 3.1 g of the amphoteric surfactant obtained in Preparation Example 20
To 233 g of aliphatic hydrocarbon solvent at 0 to 230 ° C, 309.6 g of methylene chloride quaternary product of dimethylaminoethyl methacrylate
And 620 g of an aqueous solution containing 0.03 g of 2,2'-azobis (2-amidinopropane) dihydrochloride were added and emulsified with a homogenizer.

The emulsion was transferred to a three-necked flask, degassed with N ₂ gas, and then polymerized at a temperature of 60 ° C. The polymerization was complete after about 2 hours. Subsequently, dehydration was carried out in the same manner as in Example 2 to obtain a stable water-in-oil emulsion having a polymer concentration of 54.7% and a water content in the polymer of 7.6%.

Example 4 Boiling range 2 containing 14.7 g of the amphoteric surfactant obtained in Production Example 1
250 g of aliphatic hydrocarbon solvent at 00-240 ° C., 250 g of acrylamide, 107 g of acrylic acid, 25 g of anhydrous ammonia and t
-730 g of an aqueous solution containing 0.05 g of BHP was added and emulsified with a homogenizer.

The emulsion was transferred to a three-necked flask, degassed with N ₂ gas, an aqueous solution of sodium metabisulfite was added dropwise, and the mixture was polymerized at a polymerization temperature of 50 ° C. for 3 hours, followed by HLB12.0 hydrophilic interface. 20 g of the activator was added to obtain a stable water-in-oil emulsion having a polymer concentration of 38.2%.

Example 5 The polymer concentration was 38.2% by the same procedure as in the above example except that the emulsifier in the above example was 7.4 g of the amphoteric surfactant obtained in Production Example 1 and 7.0 g of sorbitan monooleate.
A stable water-in-oil emulsion was obtained.

Comparative Example 1 In Example 1, instead of the amphoteric surfactant, a known hydrophobic surfactant (sorbitan monooleate) 17.9 g
Polymer concentration 6 by the same procedure as in Example 1 except that
An emulsion having 7.2% and a water content of 6.7% in the polymer was obtained.

Comparative Example 2 In Example 1, instead of the amphoteric surfactant, sorbitan monooleate 15.g1 and a polymeric surfactant (I
An emulsion having a polymer concentration of 67.6% and a water content of 5.8% in the polymer was obtained by the same procedure as in Example 1 except that 2.8 g of CI B-246) was used.

Example 6 50 ml of each of the emulsions obtained in Examples 1 to 3 and Comparative Examples 1 and 2 was collected in a centrifuge tube and centrifuged at 2500 rpm for 25 minutes. After centrifugation, the weight of the polymer adhered to the centrifuge tube was measured and used as a measure of separation stability. Table 1 shows the results.
Shown in

As shown in the results in Table 1, it was confirmed that the amphoteric surfactant of the present invention exhibits extremely excellent dispersion stability.

Example 7 After adding 4.5% by weight of polyoxyethylene lauryl ether (HLB12) to the emulsions obtained in Example 1 and Comparative Example 2,
An aqueous solution having a polymer concentration of 0.2% was prepared, and the increasing tendency of the viscosity after the preparation was measured with time. Table 2 shows the results.

The measurement is carried out at 25 ° C using a B-type viscometer, No. 2 rotor, 30 rpm, and the viscosity after dissolution 6 hours is 100%.
Is shown as the ratio.

As shown in Table 2, it was confirmed that in the case of using the amphoteric surfactant, the viscosity increase occurred within 5 minutes, and the demulsification was remarkably fast.

Example 8 40 parts of the emulsion obtained in Example 2 was added to 100 parts of natural rubber and kneaded with a two-roll mill. The kneaded rubber plate (thickness 3 mm) was cut into 3 cm square pieces, immersed in distilled water, and the weight was measured over time to confirm the swelling property. The results are shown in Table-3.

As a comparison, the hydropolymer emulsion before dehydration in Example 2 was tried to be kneaded with the natural rubber in a two-roll manner at the same ratio, but the hydropolymer was not uniformly kneaded with the rubber, and the rubber surface was not kneaded. separated. A tensile test piece was prepared from the swelled sample after 5 days and a tensile test was carried out, and it was confirmed that the sample had sufficient strength for practical use.

Example 9 General-purpose acrylic resin for paint (Product name: ALMATEX D
-105, Mitsui Toatsu Chemicals Co., Ltd.) 100 parts, xylene 40 parts,
15.5 parts of a curing agent (trade name: Cymel 325, manufactured by Mitsui Cyanamid Co., Ltd.) were mixed to form a basic composition of paint.

To the above paint, 15 parts each of the emulsion obtained in Example 2 and the emulsion before dehydration in Example 2 were added and mixed well.

The emulsion particles before dehydration could not be mixed uniformly because the polymer particles were aggregated and solidified, but the emulsion after dehydration was finely dispersed and a uniform coating material was obtained.

This was applied to the outer wall of a tin-made cylindrical tube for a half circumference to a film thickness of about 50 μm, left at room temperature for 3 hours, and then dried at 140 ° C. for 20 minutes. Put ice water in a tin can, 20 ℃, relative humidity 80
% It was left in a desiccator and the state of dew condensation was observed.

Condensation on the outer wall immediately occurred on the unpainted part, but no condensation was observed on the coating film even after 30 minutes. By using the emulsion of the present invention, moisture absorption and water absorption were improved.

Example 10 Polyvinyl chloride paste resin 100 parts, dioctyl phthalate 50 parts, azodicarbonamide 5 parts, calcium carbonate 50 parts, TiO ₂ 20 parts and the emulsion obtained in Example 1.
10 parts of the expandable vinyl chloride resin paste prepared by thoroughly mixing and stirring with a desper was knife-coated on a flame-retardant paper base material with a thickness of 0.15 mm, and then foamed at 180 to 200 ° C. for 1 minute, A vinyl wall covering was obtained.

After cooling this wall covering to 10 ℃, relative humidity 80%, temperature
It was placed in a desiccator at 25 ° C. and the dew condensation property of its surface was observed. At the same time, general commercial PVC wallpaper was compared.

Condensation was observed in the general commercial wallpaper immediately after it was placed in the desiccator, and condensed water began to flow after about 10 minutes, whereas in the wall covering material produced in this example, condensation was observed even after 1 hour. Was not done.

Effects of the invention As seen in the examples, the water-in-oil emulsion using the amphoteric surfactant of the present invention exhibits excellent effects on dispersion stability, and its demulsification is very fast, which is characteristic of an emulsion. Can be sufficiently exerted, and is suitably used as a flocculant, a coagulant, a tertiary oil recovery, an admixture for civil engineering construction materials, a paper-making agent, a mud conditioner, a thickener, an adhesive and the like.

Further, the dehydrated polymer can be compounded and kneaded into paint, rubber, synthetic resin, etc., which were extremely difficult in terms of compatibility and kneading property with conventional hydrous polymers, and functions such as hygroscopic water absorption and conductivity. It is preferably used as a functional raw material capable of imparting

Claims (1)

(57) [Claims] 1. A water-in-oil polymer emulsion obtained by dispersing an aqueous phase containing a polymer obtained by polymerizing one or more water-soluble vinyl monomers in an organic dispersion medium. A water-in-oil polymer emulsion containing at least 0.1% by weight of an amphoteric surfactant represented by the following general formula (1) based on the total weight of (However, R and R'represent a saturated or unsaturated hydrocarbon group having 8 to 20 carbon atoms and may be the same or different.
m and n represent an integer of 1 to 10 and may be the same or different. X represents a halogen atom. )