JPS60258203A - Manufacture of polymer - Google Patents

Abstract

PURPOSE:To obtain a carbon-contg. polymer useful as toner by making a lipophilic matter then a monomer absorb into seed polymer particles in water followed by addition of aqueous slurry of carbon black then performing polymerization using oil-soluble initiator. CONSTITUTION:A lipophilic matter (e.g., 1-chlorododecane, dioctyl adipate) and a monomer (e.g., styrene, acrylonitrile) are absorbed in this order into seed polymer particles (e.g. polystrene, styrene-butadiene copolymer) in water followed by addition of pref. 2-15wt%, based on said monomer, of carbon black, then carrying out a polymerization, thus obtaining the objective carbon-contg. particulate polymer. EFFECT:Capable of giving polymer with uniform and relatively large particle size (2-15mum), thus leading to high resolution and low-dusting when used as toner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a carbon-containing particulate polymer.

More specifically, the present invention relates to a method for producing a carbon-containing particulate polymer used as a toner for developing electrostatic latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Technical background]

If the particle size of the toner is large, the resolution of the image will be poor.
On the other hand, if the grain size of rice grains is too small, there is a problem of image fogging and contamination caused by powder scattering during development.As a toner, the grain size should be moderate (usually 2~
．． 15 am) and a particle size distribution as narrow as possible.

C. Prior Art] As a method for producing toner for developing electrostatic images, a colorant and a charge control agent are dispersed in a binder polymer by melt-kneading, which is then mechanically pulverized and classified into the required size. A common method is to extract particles in a particle size range (usually 1 to 30).

However, this method has the problem that the toner particles obtained are irregularly shaped and have a wider particle size distribution. Certainly in the method.

If the classification is finely performed, it is possible to obtain a somewhat narrow particle size distribution, but in this case, there is a problem that the yield of toner is reduced.

In so-called emulsion polymerization, in which monomers, emulsifiers, polymerization initiators, etc. are added and polymerized in water, it is possible to make spherical particles, but the particle size is usually 0.1. The particle size is ~0.3 μm, and the particle size required for toner cannot be obtained. Furthermore, in emulsion polymerization, it is difficult to incorporate carbon black into two particles. On the other hand, in so-called suspension polymerization, which uses a suspension protectant such as polyvinyl alcohol instead of an emulsifier, several large particles can be obtained, and it is relatively easy to incorporate carbon black, but the two-particle size distribution is very large. As a toner, there is a problem with resolution. Recently, J.

Ugelstad et al. added a lipophilic substance to the seed polymer particles in water to increase the monomer absorption capacity of the seed polymer particles to absorb up to 200 times the monomer compared to the second type of polymer particles, and then conducted water-soluble or oil-soluble polymerization. Initiator-
We have discovered a technology that increases polymerization.

(Unexamined Japanese Patent Application No. 54-126288, Unexamined Japanese Patent Application No. 53-7370
No. 1, JP-A-54-97582, lf! j Kaisho 54-
No. 30278) According to this technique, polymer particles having a large particle size and a uniform particle size, which was difficult to obtain in the past, were easily obtained. However, although the polymer particles obtained by this technique are preferable for toners in terms of particle size and particle size distribution, they are difficult to be colored in two colors, so they cannot be used as toners as they are. In other words, even if carbon black is mixed dry or wet with the polymer particles obtained by this technique, only a portion of the carbon black will enter the polymer, and fine particles of carbon black will be present, resulting in poor performance as a toner.

[Purpose of the invention]

In view of the above-mentioned current situation, the present inventors conducted intensive research with the aim of obtaining toner particles that have an appropriate particle size, a particle size distribution as narrow as possible, and are colored, and as a result, the present invention was developed. Reached.

[Structure of the invention]

The present invention is characterized in that after a lipophilic substance is absorbed into seed polymer particles in water, a monomer is absorbed, an aqueous slurry of carbon black is added, and polymerization is carried out using an oil-soluble polymerization initiator. This is a method for producing a polymer containing fine particles.

The configuration of the present invention will be explained in detail below. □Seed polymer particles used in the present invention are not particularly limited as long as they can be swollen with the monomers used in the present invention.1 Ordinary polymer latex, polymer emulsion, or polymer dispersion may be used.Specifically, Polystyrene-styrene-butadiene copolymers made by polymerization or suspension polymerization, carboxyl-modified styrene-butadiene copolymers, acrylic polymers, acrylic copolymers, polybutadiene, vinyl acetate polymers, vinyl chloride polymers, etc. It will be done.

In addition, if the particle size of the seed polymer particles is uniform, 2
The polymer particles obtained by the present invention are also preferred because they have uniform particle diameters.

Further, polymer particles produced by the swelling absorption polymerization method proposed by J. Ugelstad mentioned above can be used as the seed polymer particles in the present invention.

Furthermore, it is also possible to use the carbon-containing polymer particles obtained in the present invention again as the seed polymer particles in the present invention to increase the particle size.

The lipophilic substance to be absorbed into the seed polymer particles used in the present invention is a substance with a solubility in water of 10-'N/l or less, preferably xo-5g) and a molecular weight of 500
0 or less, preferably 500 or less, and specific examples thereof include 1-chlordodecane, dioctyl adipate, n-hexane, and the like.

Dioctanoyl peroxide, lauroyl peroxide, etc. can also be used as lipophilic substances, and when these are used, they can also function as a polymerization initiator.

There is no limit to the percentage of the method for absorbing the lipophilic substance into the seed polymer particles, but usually the lipophilic substance is emulsified and dispersed in water using soap or the like, and then added to the water containing the seed polymer particles. At this time, it is also possible to add a water-soluble solvent such as acetone to promote the transfer of the lipophilic substance to the seed polymer particles. Next, the monomer is added to the seed polymer particles to increase their swelling and absorption capacity, and the monomer is absorbed by the seed polymer particles.The amount of monomer added is not particularly limited as long as it can be absorbed by the seed polymer particles; Usually, it is up to 100 to 200 times the weight of the seed polymer particles. The monomers used in the present invention are not particularly limited as long as they can undergo radical polymerization; A combination is preferred. If the glass transition temperature is less than 45° C., storage stability as a toner is poor and blocking problems occur. On the other hand, if the glass transition temperature exceeds 95° C., a problem arises in the toner fixing process using current equipment (poor fixing properties due to iron, heat, or pressure).

Specific examples of monomers used in the present invention include:

Aromatic vinyl monomers such as styrene, α-methylstyrene, tyrene, p-methylstyrene, halogenated styrene, and divinylbenzene, vinyl esters such as 4-vinylpyridine, vinyl acetate, and vinyl propionate, and acrylonitrile. Unsaturated nitrile, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2
Examples include ethylenically unsaturated carboxylic acid alkyl esters such as -ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, ethylene glycol diacrylate/ethylene glycol dimethacrylate lNlN-dimethylamine ethyl methacrylate.

Conjugated diolefins such as butadiene and isoprene can also be used.

In addition, acrylamide, methacrylamide, glycidyl acrylate, glycidyl methacrylate/N-
Methylol acrylamide/N-methylolmethacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diallyl phthalate, allyl acrylate, allyl methacrylate, etc. can also be used depending on the purpose. Also acrylic acid.

Methacrylic acid, itaconic acid, fumaric acid, etc. are required.

It should be used at a proportion that does not inhibit swelling polymerization.
．． .

Can also be done.

Particularly preferred monomers for producing toner include styrene and butyl acrylate.

Divinylbenzene is mentioned.

Incidentally, when adding the monomer, a small amount of an emulsifier may be added in order to increase the stability of the obtained particles after polymerization. In that case, the amount of emulsifier added should be at most the critical cell formation concentration (C, M) at the concentration in water during micropolymerization.

C), above which small-sized polymer particles are generated during polymerization.

Carbon black used in the present invention! Carbon blanks made by any manufacturing method and use such as channel black, furnace black, and thermal black may be used.
From the viewpoint of the hue of the toner, the usual coloring color black is preferable.

In the present invention, carbon black is added in the form of an aqueous slurry to the seed polymer particles to absorb a lipophilic substance, to absorb monomers, and then before or during the initiation of double polymerization. The amount of carbon black added is 05 to 30% by weight, preferably 2 to 15% by weight, based on the monomer; if it is less than 0.5% by weight, the purpose of adding carbon black cannot be achieved; 30 weight i%
If it exceeds this, it is difficult to polymerize practically due to the polymerization retardation effect of carbon black itself.

It should be noted that after adding the aqueous slurry of carbon black, it is necessary to stir it thoroughly, and the stirring means is not particularly limited and may be any stirring used in ordinary polymerization reactions.

In the present invention, carbon black is added in the form of an aqueous slurry, but when carbon black is added in the form of powder,
Dispersion is insufficient, and the proportion of carbon black in the resulting particles after polymerization is small.

A large amount of carbon blank aggregates are present along with colored polymer particles.

In the present invention, after the aqueous slurry of carbon black has been allowed to absorb the lipophilic substance into the seed polymer particles.

If the monomer is added before absorption and the monomer is added first, the monomer will adhere not only to the seed polymer particles but also to the carbon black particles, and when this polymerizes, the resulting particles will have an uneven particle size distribution. . Also after seeding the aqueous slurry of carbon black with lipophilic substances into the polymer particles.

When added after absorbing the monomer and polymerizing using an oil-soluble polymerization initiator - It is impossible to incorporate carbon blank particles into the polymer particles.

The polymerization initiator used in the present invention is an oil-soluble polymerization initiator, such as azobisisobutylnitrile (hereinafter referred to as AIBN), benzoyl peroxide, 2.4
Examples include '-dichlorobenzoyl peroxide, dioctyl peroxide, lauroyl peroxide, etc., which may be used alone or in mixtures. The oil-soluble polymerization initiator is usually dissolved in a monomer or a solvent described later and added to the polymerization system.

Note that in the present invention, a water-soluble polymerization initiator such as hydrogen peroxide or potassium persulfate is used.

A large amount of small-sized polymer particles are generated and the performance as a toner deteriorates.

In the present invention, during one polymerization, a polymerization regulator such as carbon tetrachloride + t-dodecyl mercaptan, hydro #/7. N, N
- A water-soluble polymerization inhibitor such as diethyl hydroxylamine and a protective colloid such as polyvinyl alcohol may be added. The presence of a water-soluble polymerization inhibitor is effective in suppressing the generation of small-sized polymer particles.

(1) The carbon-containing particulate polymer obtained by the method of the present invention is useful as a toner, as described later.

Further, it is possible to further improve the performance as a toner by adding a charge control agent, an antiblocking agent, a dye, etc. to the polymer.

〔Example〕

! : Examples and comparative examples are given below to provide a more detailed explanation of the present invention. Naturally, the present invention is not limited to the following examples.

Example-1 (Preparation of seed polymer particles) Styrene-butadiene latex A (styrene/butadiene-50750, average particle diameter 022 μm, standard deviation value of particle diameter 0.02 μm, solid content) obtained by ordinary emulsion polymerization 21.5%) (as solid content), 2 g of l-chlordodecane and 0.15% of sodium lauryl sulfate. ! i
An emulsion prepared by adding 10 ml of water, 0 g of water and 3 y of acetone was added, and the mixture was stirred for 12 hours to allow Latex A to absorb 1-chlordodecane. Styrene 83. ? and butyl acrylate-417FK azobisisoputiloni) IJ
Le II! Add the dissolved mixture and 150g of water,
The latex A was stirred for 0 minutes to absorb the monomer and azobisisobutyronitrile, and polymerization was carried out at 70° C. for 12 hours. Average particle size 1.0 μm at polymerization conversion rate of 95 cm
Latex B (seed polymer particles) was obtained, which consisted of spherical particles with a standard deviation value of 1 particle size of 012 μm and substantially uniform particle size.

Latex B had no carbon black agglomerates.

(Method for producing toner) A toner was produced by the following method using the latex B described above as seed polymer particles.

Add 2 g of 1-chlordodecane to Latex BII and 0.15 g of lauryl sulfur soda. li', water 10. ? Add emulsified liquid made with 3 g of acetone and stir for 12 hours.
Latex B was allowed to absorb 1-chlordodecane. This includes styrene 839 and butyl acrylate) 17. A mixture of azobisin butyronitrile II dissolved in F and 150 liters of water were added and stirred for 30 minutes to allow latex B to absorb the monomer and azobisin butyronitrile. Next, Mitsubishi Carbon Black MA-600 (
(manufactured by Mitsubishi Kasei ■) was placed in 100 g of water and sufficiently suspended using a homogenizer. Carbon slurry prepared by stirring No. 8 was added thereto, and polymerization was carried out at 70° C. for 12 hours while stirring at a high intensity.

Latex C was obtained at a polymerization conversion rate of 95 cm and an average particle size of 4.7 μm and a standard deviation value of 0.5 μm per particle size. The latex C was centrifuged to precipitate two particles, which were dried under reduced pressure at 20°C to obtain a black toner powder.

(Toner Performance Evaluation Method rA) Image Formation A two-component developer was prepared by mixing 5 parts by weight of toner powder and 95 parts by weight of DSF iron powder carrier (manufactured by Dowa Iron Powder Industries ■). Using this developer, electronic copying machine 1'-XEROX
A development test was conducted using 2970J (manufactured by Fuji Celonox ■).

[B) Resolution Image Electronics Engineers of Japan facsimile test chart NO! −
Evaluation was made using R. (In Table 1, 4 good = ○.) [C] Powder stain [B] Judgment was made based on the carbon stain in the blank area of the chart used. (In Table 1, no stains = ○, large stains = △.) [1)) Fixability A copy immediately after coming out of the electronic copying machine "XB ROX 2970J" was rubbed by hand, and judgment was made based on the fixed state of the image. (Table 1) 1
Good = ○. ) (E) Blocking toner powder 100. F was placed in a paper bag, a load of 100 g/l was applied to the bag, and the state of the toner was evaluated after 24 hours at 30°C. (In Table 1, no blocking was set as 10.) (Measurement of particle size) Particle size was measured using electron microscope photography, and 5.
Measure the particle size of 0 particles or more.

The average particle size value and the standard deviation value of particle size were calculated.

(Glass-transition temperature) Measured by DSC method.

The above results are shown in Table 1. As Comparative Example 1, a commercially available toner for copiers (XEROX297 manufactured by Fuji Xerox) was used.
0 toner/product code D211),,,□1e,□1
．． Yo, yeah. )2: Examples-2 to 4 In the toner manufacturing method in Example 1.

A black toner was produced in the same manner as in Example 1, except that latex C was used as the seed polymer particles instead of latex B, and the weight ratio of latex C to monomer (latex/monomer) and the polymerization conversion rate were changed as shown in Table 1. A powder was prepared. Table 1 shows the performance evaluation results of the obtained toner powder.

Examples 5 to 6 Example 1 except that in the toner manufacturing method of Example 1, latex C was used as the seed polymer particles instead of latex B, and the weight ratio of latex C and the monomers styrene and butyl acrylate was increased. A black toner powder was prepared in the same manner as in Example 1. The performance evaluation results of the obtained toner powder are shown in Table 1. Example 7 In the toner manufacturing method in Example 1, polystyrene latex (average particle size 0.4) was used instead of latex B.
Standard deviation value of 5 μm 1 particle size 0.10 μm.

Hereinafter, it will be referred to as latex D. ) was used as the seed polymer particles, and a black toner powder was produced in the same manner as in Example 1, except that the polymerization conversion rate was 97%.

Table 1 shows the performance evaluation results of the obtained toner powder.

Comparative Example 2 1-chlordodecane 211 was added to the latex BIJ prepared in Example 1 with 0.15 I of sodium lauryl sulfate and 10 I of water.
．． Add an emulsion made with P and 3 g of acetone, and add 12
The latex B was stirred for an hour to absorb the 1-chlordodecane. In addition to this, 5g of the aforementioned carbon black, 83g of styrene, and 17I of butyl acrylate! and 0.5 g of azobisisobutyronitrile and stirred for 12 hours.

Although the monomer was absorbed into latex B.

Carbon black only became aggregates and was suspended in water.

This was polymerized as it was at 70°C, but substantially no carbon black was contained in the resulting polymer particles.

Comparative example 3 In the toner manufacturing method in Example 1.

Polymerization was carried out in the same manner as in Example 1, except that azobisisobutyronitrile O in the monomer was used and a water-soluble polymerization cut-out (an aqueous solution in which 0.5y of potassium persulfate was dissolved in water) was used during the bipolymerization.

When the obtained polymer particles were observed under an electron microscope,
Most of the particles were small particles with a size of 0.15 to 0.3 μm, and carbon black particles were also present as they were.

It is thought that because a water-soluble polymerization initiator was used, new particles were generated during double polymerization, and carbon black did not enter the particles.

Example-8 Latex DIII (as solid content) was mixed with 2 g of 1-chlordodecane and 0.15 g of sodium lauryl sulfate and 10F water.
An emulsion obtained by emulsifying the mixture with 3 g of acetone was added and stirred for 12 hours to allow Latex D to absorb 1-chlordodecane. To this, a solution of 40 g of divinylbenzene, 40 g of vinylpyridine, 20 g of butyl acrylate, and azobisisobutyronitrile IJ9 dissolved in 100 g of toluene, and 200 g of water were added, and the mixture was stirred for 30 minutes to dissolve the monomer and azobisisobutyronitrile in Latex D. Butyronitrile was absorbed. Next, Mitsubishi Carbon Black MA-600
5I (manufactured by Mitsubishi Kasei ■) in water '100 If was sufficiently suspended and stirred using a homogenizer, a carbon slurry was added thereto, and polymerization was carried out at 70° C. for 12 hours while stirring at a high intensity.

At a polymerization conversion rate of 95%, the particles were sedimented and taken out by centrifugation, washed with acetone to extract the toluene inside the particles, and dried under reduced pressure at 20°C to obtain a black toner powder containing carbon black. Ta.

Next, the powder was dispersed again in water 11, and ferrous chloride hexahydrate 6
0y, add a solution of 25II of ferric chloride tetrahydrate and 1 part of water, and while reducing the pressure to lQ mmHg, 1□13
Stirring was performed for 0 minutes. After returning the liquid to normal pressure.

The pH was raised to pH 8.0 with 25% ammonia water and further heated at 80°C for 30 minutes. The liquid was filtered and dried under reduced pressure at 20° C. to obtain a black magnetic toner powder containing 25% of magnetic material (magnetite) and 5 grams of carbon blank.

The average particle size of the powder is 2.2 μm, and the standard deviation value of particle size is 0.
It was 42 μm and had a glass transition temperature of 72° C., and strongly adhered to the magnet.

C Effect of invention] The effects of the present invention are listed below.

(1) Carbon black can be incorporated into particles by swelling absorption polymerization.

(2) The polymer particles obtained in the present invention have a large particle size.

(3) In the present invention, the particle size of the resulting polymer particles can be made uniform depending on the seed polymer used.

(4) The carbon-containing polymer particles obtained by the present invention are:
It is useful as a toner because of its large particle size (2-15 am) and uniform particle size. (Good resolution and less powder dirt.) Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] (1) After absorbing a lipophilic substance into seed polymer particles in water, absorbing a 7-mer, an aqueous slurry of carbon black is added, and polymerization is carried out using an oil-soluble polymerization initiator. A method for producing a carbon-containing particulate polymer.