JPS6195003A - Production of hydrophilic group-containing vinyl polymer - Google Patents

Abstract

PURPOSE:To obtain the titled polymer useful as a toner for electrostatic charge development in high operation efficiency in high yield stably, by adding dropwise a vinyl monomer having a hydrophilic group-containing vinyl monomer to an aqueous medium having dissolved a water-soluble polymerization inhibitor and an electrolyte to polymerize the monomer. CONSTITUTION:A vinyl monomer (e.g., styrene, etc.) having usually >=10wt% hydrophilic group-containing monomer (e.g., vinyl monomer containing OH group and/or COOH group, etc.) is added dropwise to an aqueous medium heated to a temperature capable of polymerizing the vinyl monomer, the vinyl monomer is subjected to suspension polymerization, to give a hydrophilic group-containing vinyl polymer. In the operation, a water-soluble polymerization inhibitor (e.g., NaNO2, KNO2, CuCl2, etc.) and an electrolyte (e.g., NaCl, KCl, etc.) are predissolved in the aqueous medium in such a way that an amount of the polymerization inhibitor is >=0.001wt%, and an amount of the electrolyte is >=0.001wt%, and the total amounts of them is <=1wt%. EFFECT:The use of both the water-soluble polymerization inhibitor and the electrolyte prevents emulsion polymerization and attachment to a reactor, and suppresses formation of fine particles which cause clogging.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a binder resin used in toners for developing electrostatic images, and more specifically, to a method for producing a binder resin for use in toners for developing electrostatic images. This invention relates to a method for legally producing a hydrophilic group-containing vinyl polymer.

Conventionally, vinyl polymers containing hydrophilic groups such as a small number of hydroxyl groups and carboxyl groups, that is, hydrophilic group-containing vinyl polymers, have been produced by various polymerization methods, but in particular suspension polymerization has been replaced by solution polymerization. In comparison, it does not use solvents, and
In that the reaction is easier to control than the bulk polymerization method,
Furthermore, this method is superior to the emulsion polymerization method in that the polymerized resin can be easily separated.

By the way, in the conventional suspension polymerization method, a monomer containing a polymerization initiator is added all at once to water in which a suspending agent such as starch, gelatin, polyvinyl alcohol, or tricalcium phosphate is dissolved, and the reaction does not proceed rapidly. After suspending in the form of oil droplets at room temperature, the suspension is heated to the reaction temperature,
The reaction is completed by keeping at the same temperature for 2 to 8 hours. When attempting to produce a hydrophilic group-containing vinyl polymer using this method, shortly after the start of the reaction, the half-polymers that had been suspended in the form of particles fuse together and grow into large lumps (hereinafter referred to as a glutinous phenomenon).
As a result, the desired particulate polymer could not be obtained.

The reason why hydrophilic group-containing vinyl monomers tend to become cake-like is that the monomers are hydrophilic, so the oil layer (
The boundary between the monomer (monomer) and the water layer is not clear, and as the reaction progresses, the sticky particles come into contact with each other during stirring, fuse together, and form a lump.

To solve this problem, a method is proposed in which a vinyl monomer containing a hydrophilic group is added dropwise to water heated to a temperature at which the vinyl monomer can be polymerized (Japanese Patent Laid-Open No. 59-78202). Publication No.) is known. This method is said to be a successful method for obtaining hydrophilic group-containing vinyl-17 polymers without causing cake-like formation.

However, even in the method disclosed in JP-A-59-78202, a portion of the vinyl monomer undergoes emulsion polymerization, causing damage to the inner wall of the reaction vessel, stirring blades, stirring rods, etc. Since the particles tend to accumulate on the parts, a cleaning process is required for each batch, which reduces work efficiency.Also, since the generated particles include fine particles of several micrometers, even in the over-process, the r-over-initial stage There is a problem in that the yield and work efficiency are reduced, such as fine particles flowing out with water and clogging of the T-cloth in the middle to late stages of the process, making it impossible to continue the process. The object of the present invention is to provide a method for producing a hydrophilic group-containing vinyl polymer that can solve these problems and stably obtain a hydrophilic group-containing vinyl polymer in high yield.

In order to increase the same side ζ, the present invention involves adding dropwise a vinyl monomer containing a hydrophilic group-containing vinyl monomer to an aqueous medium heated to a temperature at which the vinyl monomer can be polymerized, and causing suspension polymerization. In the method for producing a hydrophilic group-containing vinyl polymer, a water-soluble polymerization inhibitor and an electrolyte are added in advance to the aqueous medium in an amount of 0.001% or more by weight of each of the total vinyl monomers,
The present invention relates to a method for producing a hydrophilic group-containing vinyl polymer, characterized in that the total amount thereof is dissolved in an amount of 1% by weight or less.

The vinyl monomer of the present invention consists of only a hydrophilic group-containing vinyl monomer or a mixture of a hydrophilic group-containing vinyl monomer and another vinyl monomer copolymerizable therewith. In the present invention, a suspension polymerization method is employed in which the vinyl monomer is dropped into water heated to a polymerizable temperature, and by doing so, it is possible to prevent cake-like formation during polymerization. This method is
Especially when a large amount of hydrophilic group-containing vinyl monomer is used,
When the proportion of the hydrophilic group-containing vinyl monomer in the vinyl monomer of the present invention is 10% by weight or more, the effect is remarkable.

The hydrophilic group-containing vinyl monomers include 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxy-3-phenyloxypropyl methacrylate, hydroxybutyl methacrylate, and a halfester compound of glycidyl methacrylate and methacrylic acid or acrylic acid. , halfester compound of bisphenol type epoxy resin and methacrylic acid or acrylic acid, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxy-3-phenyloxypropyl acrylate, hydroxybutyl acrylate, glycidyl acrylate and methacrylic acid Alternatively, hydroxyl group-containing vinyl monomers such as hafestation products of acrylic acid, acrylic acid, methacrylic acid, maleic acid, fumaric acid, mesaconic acid, itaconic acid, citraconic acid, formula: (wherein R1 represents hydrogen or a methyl group, R2 represents an alkylene group having 1 to 10 carbon atoms, R3 represents an alkylene group having 1 to 10 carbon atoms or an aromatic ring or a derivative thereof, and n represents an integer of 1 to 3); Carboxyl group-containing vinyl monomers such as adducts of maleic acid, fumaric acid, itaconic acid, or citraconic acid with glycidyl acrylate or methacrylate, or epoxy resins, vinyl acetate, acrylamide,
Although there are methacrylamide and the like, hydroxyl group-containing vinyl monomers and carboxyl group-containing vinyl monomers are mainly used.

Other vinyl monomers copolymerizable with the hydrophilic group-containing vinyl monomer include styrene, α-methylstyrene, p-
Styrene derivatives such as methylstyrene, pt-butylstyrene, p-chlorostyrene, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate , nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, methacrylic acid Butoxytriethylene glycol, methoxydipropylene glycol methacrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, dicyclopentenyl methacrylate, methacrylate dicyclopentenyloxyethyl acid, N-vinyl-2-pyrrolidone methacrylate, (,, l glycidyl methacrylate, methacrylatelyl, N-methylol methacrylamide, diacetone acrylamide, methyl acrylate, ethyl acrylate, propyl acrylate, Butyl acrylate, pentyl acrylate, hexyl acrylate, hebutyl acrylate,
Octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, methoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene acrylate glycol,
Butoxytriethylene glycol acrylate, acrylic methoxydipropylene glycol, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate,
Benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl-2-pyrrolidone acrylate, glycidyl acrylate, acrylonitrile, N-methylol acrylamide, di 1 in 1 molecule of acetone acrylamide etc.
Vinyl monomers having vinyl groups, divinylbenzene, reaction products of glycol and methacrylic acid or acrylic acid, such as ethylene glycol dimethacrylate, 1.3-butylene glycol dimethacrylate, 1.
4-butanediol dimethacrylate, 1.5-bentanediol dimethacrylate, 1.6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate,
Triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, hydroxypivalic acid neopentyl glycol ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerydrift tetramethacrylate ,
Tris methacryloxethyl phosphate, bis(methacryloyloxyethyl) hydroxyethyl isocyanurate, tris(methacryloyloxyethyl) isocyanurate, ethylene glycol diacrylate, 1゜3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-bentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene diacrylate, neopentyl glycol hydroxypivalate Diacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, pentaerydrift triacrylate, pentaerydrift tetraacrylate, trisacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacryloyloxyethyl) Examples include vinyl monomers having two or more vinyl groups in one molecule, such as isocyanurate.

Among these, preferable vinyl monomers having one vinyl group in one molecule include styrene, styrene derivatives, methacrylic esters, acrylic esters, and in particular those having 1 to 5 vinyl groups in the alkyl group. Preferred are alkyl esters of methacrylic acid or acrylic acid containing carbon atoms, and examples of vinyl monomers having two or more vinyl groups in one molecule include divinylbenzene, dimethacrylate and diacrylate of methylene glycol having 2 to 6 carbon atoms. etc. are preferred. These are used in an amount of 0 to 20% by weight based on the total vinyl monomers.

As a polymerization initiator, acetyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, p-peroxide
Chlorobenzoyl, perMated2. 4-Dichlorobenzoyl, diisopropyl perdicarbonate, di-2-ethylhexyl perdicarbonate, acetyl cyclohexane sulfonyl peroxide, tert-butyl peracetate, tert-butyl perisobutyrate, azobisisobutyronitrile, per2- Tert-butyl ethylhexanoate, tert-butyl perbenzoate, etc. can be used. The amount of these polymerization initiators is 0.0% based on the total amount of vinyl monomer.
It is preferable to use it by melting it in an amount of 1 to 15% by weight.

In the present invention, dispersants include gelatin, gum tragacanth, starch, methylcellulose, carboxymethylcellulose, polyvinyl alcohol, partially saponified polyvinyl alcohol, water-soluble polymeric substances such as polyacrylic acid, organic dispersants such as alginate, barium sulfate, Calcium sulfate, calcium carbonate, barium carbonate, magnesium carbonate, tricalcium phosphate, talc, bentonite,
Any conventionally known dispersants such as poorly soluble inorganic dispersants such as diatomaceous earth and clay can be used. The organic dispersant is preferably used in an amount of 1xto-4 to 5% by weight, and the inorganic dispersant is preferably used in an amount of 0.01 to 3% by weight based on the total amount of vinyl monomers used.

In addition, as a dispersion aid, an alkylbenzene sulfonate such as sodium dodecylbenzene sulfonate, an alkyl sulfonate in which SO3Na is directly bonded to an alkyl group,
Anionic surfactants such as β-tetrahydronaphthalene sulfonate, amidosulfonates such as sodium N-isopropylcyclohexylamide sulfonate, and higher fatty acid salts such as sodium oleate may be used in combination with the above dispersant. can. In particular, when an inorganic dispersant is used as a dispersant, it is preferable to use a dispersion aid together. The dispersion aid is lXl0 for all the vinyl monomers used.
It is preferably used in an amount of -4 to 0.01% by weight.

In the present invention, examples of the water-soluble polymerization inhibitor include sodium nitrite, potassium nitrite, cupric chloride, etc., but sodium nitrite is particularly preferred from the viewpoint of effectiveness. The amount of polymerization inhibitor added is 0.0 based on the total vinyl monomer.
0.01% by weight or more, particularly preferably 0.005% by weight or more. When the amount added is less than 0.001% by weight,
Emulsion polymerization cannot be prevented, resulting in increased adhesion to the reaction vessel and generation of fine particles.

In the present invention, the electrolyte is added for the purpose of reducing the solubility of the hydrophilic vinyl monomer in water, and includes, for example, potassium chloride, sodium chloride, calcium chloride,
Examples include magnesium chloride, aluminum chloride, sodium sulfate, magnesium sulfate, aluminum sulfate, potassium aluminum sulfate, and the like.

The amount of electrolyte added is 0.00 based on the total vinyl monomer.
It is 1% by weight or more, preferably 0.005% by weight or more.

The above-mentioned water-soluble polymerization inhibitor and the above-mentioned electrolyte are used so that the total amount thereof is 1% by weight or less, particularly preferably 0.5% by weight or less, based on the total vinyl monomer. If the above total exceeds 1% by weight, it tends to become cake-like during polymerization.

Further, if the amount of these is increased, the particle size of the polymer particles becomes large, which not only makes stirring difficult but also makes handling inconvenient, so it is preferably 0.5% by weight or less. Particularly preferably, the water-soluble polymerization inhibitor and the electrolyte each contain 0.05 iff1% of the total vinyl monomer.
Used below.

In the present invention, water is mainly used as the aqueous medium for suspension polymerization. A dispersant and, if necessary, a dispersion aid are added to this medium in advance.

The vinyl monomer is dropped into water as a medium, but at this time the water is already heated to a temperature at which the vinyl monomer can polymerize. Here, the polymerizable temperature is equal to or higher than the decomposition start temperature of the polymerization initiator used. This temperature varies depending on the polymerization initiator used, but for example, when benzoyl peroxide, tert-butyl per2-ethylhexanoate, etc. are used, it is 50°C or higher, and diisopropyl perdicarbonate, di2- 3 for ethylhexyl
The temperature is 0°C or higher. If the vinyl monomer is dropped into a medium that has not been heated to a temperature at which the vinyl monomer can be polymerized, caking occurs, as in conventional methods. There are no particular restrictions on the total amount of vinyl monomer used (A) and the amount of water used (B), but (A) N/(B)
If the ratio is too large, suspension polymerization cannot be carried out smoothly, so the weight ratio of (A)/(B) is preferably 75/25 or less, particularly preferably 60/40 or less.

The vinyl monomer addition rate is preferably on average 16.7 g/min or less per M11 kg of vinyl monomer and water used. This addition rate (unit: g/min・kg) is the vinyl monomer dropping rate・(unit: 2 g/min.
minutes), the total amount of vinyl monomer and water used (unit:
kg). Average addition rate: 16.7g
If the amount exceeds 1 kg/min, there is a tendency for cake formation to occur during polymerization. If the addition rate is too low, the polymerization time will become long, so it is preferably 1.38 g/min.kg or more, particularly preferably 4 to 8.5 g/min.kg. The rate of addition is preferably uniform during the addition, but may vary. In this case, it is preferred that the addition rate does not exceed 16.7 g/min.kg. This addition rate can be commonly applied even when the ratio of the aqueous medium to the vinyl monomer and the amounts used thereof are varied.

Next, the present invention will be described in detail based on examples, but the present invention is not limited thereto.

Example 1 Parts by weight (1) Medium water 1000 Polyvinyl alcohol (Denka Poval W-24, Denki Kagaku Kogyo Co., Ltd. trade name) 3 Sodium nitrite 0.1 (0.C11ffi amount % based on vinyl monomer) Sodium chloride
0.1 (0.1 for vinyl monomer)
0IFtH%) (2) Dropped liquid Styrene 500 n-butyl methacrylate 100 β-hydroxyethyl methacrylate 400 Benzoyl peroxide 3
0Pour the medium having the composition in (1) above into a reaction container, raise the temperature of the liquid to 90°C, and then drop the dropping liquid having the composition in (2) above at a uniform rate over 1.5 hours. , and kept at the same temperature for 4 hours. The amount of W applied to the reaction vessel was 0.06% (based on the total vinyl monomer), and the obtained polymer was granular with an average diameter of 1xx. 200 mesh?
Can you use cloth without causing clogging? The yield of the polymer was 99%. The addition rate in this example was 5.6 g/min.kg. Note that the vinyl monomer dropping rate was 11.1 g/min.

Example 2 Parts by weight (1) Medium water 1000 Polyvinyl alcohol (Gohsenol G) I-20, Nippon Gosei Chemical Industry (trade name) 3 Sodium nitrite 0.3 (0.03°C 1% based on vinyl monomer) Chloride sodium
0.2 (0.0 for vinyl monomer
2% by weight) (2) Dropped liquid styrene 600 acrylic acid n
-Butyl 100 β-Hydroxypropyl methacrylate 300 Benzoyl peroxide 50 After putting the medium having the composition of (1) above into a reaction container and raising the liquid temperature to 90°C,
The dropping liquid having the composition (2) above was added dropwise at a uniform rate over a period of 1 hour, and maintained at the same temperature for 4 hours. The amount deposited on the reaction vessel was 0.05% (based on total vinyl monomer), and the resulting polymer was granular with a diameter of about 1 inch. 200 mesh? The cloth can be used without clogging, and the polymer yield is 99%.
Met. The addition rate in this example is 8.3 g/min·k
It was g. Note that the vinyl monomer dropping rate was 16.
It was 7g/min.

Example 3 Part by weight (1) Medium water 1200
; Polyvinyl alcohol (GOHSENOL 0H-20) d Sodium nitrite 0.5 (0.05% by weight based on vinyl monomer) Sodium chloride
0.2 (0.02ffi for vinyl monomer
(%) (2) Dropped liquid styrene 450 ethyl methacrylate 100 n-butyl acrylate
゛ 100 β-hydroxypropyl methacrylate
150 methacrylic acid
200 Benzoyl peroxide 50 Put the medium consisting of the composition of (1) above into a reaction container, and lower the liquid temperature to 9.
After raising the temperature to 0° C., the dropping liquid having the composition (2) above was added dropwise at a uniform rate over a period of 1 hour, and the temperature was maintained at the same temperature for 5 hours. The amount of adhesion to the reaction vessel was 0.08% (based on the total vinyl monomer), and the obtained polymer had a diameter of approximately 1.5%.
It was a particulate matter. Using 200 mesh T cloth,
It was possible to process the polymer without clogging, and the yield of the polymer was 99%. The addition rate in this example was 7.6 g/min.kg. Note that the vinyl monomer dropping rate was 16.7 g/min.

Example 4 A hydrophilic group-containing vinyl polymer was produced in exactly the same manner as in Example 2 except that sodium chloride was replaced with potassium chloride. As a result, the amount of adhesion to the reaction vessel was 0.05%, and the polymer was approx. It was 1 dragon's worth of granules.

No clogging occurred even after passing through a 200-mesh R cloth, and the yield was 99%.

Example 5 A hydrophilic group-containing vinyl polymer was produced in the same manner as in Example 2 except that cupric chloride was used instead of sodium nitrite. The coalescence was about 1 crane of granules.

Even when a 200-mesh T-cloth was used, no clogging occurred, and the yield was 99%.

Comparative Example 1 The reaction was carried out in exactly the same manner as in Example 1 except that sodium nitrite was removed. As a result, the amount of adhesion to the reaction vessel was 0.2
% (based on all vinyl monomers), which was higher than the 0.06% adhesion i in Example 1.

Note that the obtained polymer was a granular material with an average particle size of 1 mm.

Comparative Example 2 The reaction proceeded in exactly the same manner as in Example 2 except that sodium nitrite and sodium chloride were removed. As a result, the amount of adhesion to the reaction vessel was 2.6% (based on the total vinyl monomer).
The obtained polymer was a granular material with an average particle size of 1.5 mm. Also, 200 mesoyu? The cloth was clogged, and the cloth was changed three times to get all the polymer through. Yield was 90%.

Effects of the Invention According to the present invention, a hydrophilic group-containing vinyl polymer can be produced with high working efficiency and high yield, and adhesion to the reaction vessel is extremely reduced.

Claims (1)

[Scope of Claims] 1. A vinyl monomer containing a hydrophilic group-containing vinyl monomer is added dropwise to an aqueous medium heated to a temperature at which the vinyl monomer can be polymerized, and suspension polymerization is performed to produce a vinyl monomer containing a hydrophilic group. In the method for producing a polymer, a water-soluble polymerization inhibitor and an electrolyte are added to the aqueous medium in advance in an amount of 0.001% by weight or more of each of the total vinyl monomers, and the total amount is 1% by weight or less. 1. A method for producing a hydrophilic group-containing vinyl polymer, which is characterized in that it dissolves in small quantities. 2. The method for producing a hydrophilic group-containing vinyl polymer according to claim 1, wherein the water-soluble polymerization inhibitor is sodium nitrite, potassium nitrite, or cupric chloride. 3. Vinyl monomer contains 10% by weight of hydrophilic group-containing monomer
A method for producing a hydrophilic group-containing vinyl polymer according to claim 1 or 2, including the above. 4. The method for producing a hydrophilic group-containing vinyl polymer according to claim 1, 2 or 3, wherein the hydrophilic group-containing monomer is a hydroxyl group-containing vinyl monomer and/or a carboxyl group-containing vinyl monomer.