JPH0582941B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a liquid developer for developing electrostatic images formed by electrostatic photography such as electrophotography and electrostatic recording. ``Prior Art'' Liquid developers for electrostatic images generally contain carbon black, carbon black,
It is a product in which particles of various colorants such as phthalocyanine are dispersed, but resin is usually attached to the surface of the colorant particles in order to adjust the charge and impart dispersibility, fixability, etc., and this is used as a toner. There are many things. Additionally, additives such as a dispersant and a polarity control agent may be added to the carrier liquid as necessary. Conventionally, resins attached to colorants include rosin, natural rubber, alkyd resin, phenolic resin, epoxy resin, pentaerythritol resin,
Natural resins and synthetic resins such as acrylic resin and synthetic rubber are known. It is difficult to obtain natural resins of consistent quality, and synthetic resins such as acrylic resins do not necessarily have sufficient dispersibility, fixing properties, or good charging characteristics, and also tend to cause particle aggregation or sedimentation over time. There were practical problems, such as the fact that it was easy to wake up. "Problems to be Solved by the Invention" As a result of intensive research in order to improve the above-mentioned drawbacks, the inventors of the present invention have found a solution in Japanese Patent Application Laid-Open No. 105235/1983 (U.S. Pat.
4473630), we have found a liquid developer for electrostatic images with improved dispersibility and fixing properties. As a result of further extensive research, the present inventors have arrived at the present invention, which has even better charging characteristics than that of JP-A-58-105235. The first object of the present invention is to improve the dispersibility of a toner for a liquid developer for electrostatic images consisting of colorant particles and resin in a liquid developer, and to improve the storage stability when the developer is stored for a long period of time. The purpose is to improve and improve stability. A second object of the present invention is to provide a liquid developer for electrostatic images with excellent fixing properties. Furthermore, a third object of the present invention is to provide a liquid developer for electrostatic images that exhibits good charging characteristics, such as excellent charging stability over time and repeated use stability. "Means for Solving the Problems" The developer of the present invention comprises a resin containing at least one polymerizable monomer represented by the following general formula (1) and chloromethylstyrene as copolymer components. , a liquid developer for electrostatic images dispersed in a carrier liquid having an electrical resistance of 10 ⁹ Ω-cm or more and a dielectric constant of 3 or less.

embedded image In the formula, A represents a hydrogen atom or a methyl group, and B represents any of the following general formulas (2), (3), (4), (5), and (6).

[ka]

[ka]

[ka]

[ka]

embedded image In the formula, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group. In that case, R ₁ and R ₂ may be the same or different. Also
A ring can also be formed by R ₁ and R ₂ and the nitrogen atoms described in general formulas (2) to (6). In that case, the ring can contain carbon, oxygen, nitrogen, and sulfur as constituent elements. The total number of carbon atoms in R ₁ and R ₂ is 36 or less. n represents a positive integer from 1 to 6. Examples of the polymerizable monomer represented by the general formula (1) include N,N-dimethylaminostyrene, N,
N-diethylaminostyrene, N,N-dipropylaminostyrene, N,N-dibutylaminostyrene, N,N-dihexylaminostyrene, N,
N-dioctylaminostyrene, N,N-dilaurylaminostyrene, N,N-di-stearylaminostyrene, N-methylaminostyrene, N-
Ethylaminostyrene, N-propylaminostyrene, N-butylaminostyrene, N-octylaminostyrene, N-laurylaminostyrene,
N-methyl-N-phenylaminostyrene, N-
Ethyl-N-phenylaminostyrene, N-methyl-N-benzylaminostyrene, N-ethyl-
N-benzylaminostyrene, morpholinostyrene, piperidinostyrene, N-naphthyl-N-ethylaminostyrene, N-anthryl-N-ethylaminostyrene, N-phenanthryl-N-ethylaminostyrene, N,N-dimethylamino Ethyl methacrylate, N,N-diethylaminoethyl methacrylate, N,N-dipropylaminoethyl methacrylate, N,N-dimethylallylamine, N,N-diethylaminoethylamine, N,N
-dipropylarylamine, N,N-dimethylaminomethylstyrene, N,N-dimethylaminoethylstyrene, N,N-diethylaminomethylstyrene, N,N-dipropylaminomethylstyrene, N,N-dibutylaminomethylstyrene,
N,N-dihexylaminomethylstyrene, N,
N-dioctylaminomethylstyrene, N,N-
Dilaurylaminomethylstyrene, N,N-distearylaminomethylstyrene, N-methylaminomethylstyrene, N-ethylaminomethylstyrene, N-propylaminomethylstyrene, N-
Butylaminomethylstyrene, N-octylaminomethylstyrene, N-laurylaminomethylstyrene, N-methyl-N-phenylaminomethyl-styrene, N-ethyl-N-phenylaminomethylstyrene, N-methyl-N -benzylaminomethyl-styrene, N-ethyl-N-benzylaminomethylstyrene, morpholinomethylstyrene, piperidinomethylstyrene, N-naphthyl-
N-ethylaminomethylstyrene, N-anthryl-N-ethylaminomethylstyrene, N-phenanthryl-N-ethylaminomethyl-styrene, N,N-dimethylamino-methoxymethylstyrene, N,N-dimethylaminoethoxymethylstyrene , N,N-dimethylamino-propoxymethylstyrene, N,N-dimethylaminobutoxymethylstyrene, N,N-dimethylamino-pentoxymethylstyrene, N,N-dimethylaminohexyloxymethylstyrene, aminoethoxymethylstyrene, N,N-diethylaminoethoxymethylstyrene, N,N-dipropylaminoethoxymethyl-styrene, N,N-dibutylaminoethoxymethylstyrene, N,N-dihexylaminoethoxy-methylstyrene, N,N-dioctylaminoethoxymethyl Styrene, N,N
-Dilaurylaminoethoxy-methylstyrene-
N,N-distearylaminoethoxymethylstyrene, N-methylaminoethoxymethylstyrene, N-ethylaminoethoxy-methylstyrene, N-propylaminoethoxymethylstyrene, N-butylaminoethoxymethyl-styrene, N-octylaminoethoxy Methylstyrene, N-laurylaminoethoxymethyl-styrene, N-methyl-N-phenylaminoethoxymethylstyrene, N-ethyl-N-phenyl-aminoethoxymethylstyrene, N-methyl-N-benzylaminoethoxymethylstyrene, N-ethyl-N-benzylaminoethoxymethylstyrene, morpholinoethoxymethylstyrene, piperidinoethoxymethylstyrene, N-naphthyl-N
Examples include -ethylaminoethoxymethylstyrene, N-anthryl-N-ethylaminoethoxymethylstyrene, and N-phenanthryl-N-ethylaminoethoxymethylstyrene. Examples of the polymer used in the present invention include a copolymer of the polymerizable monomer represented by the general formula (1) and chloromethylstyrene, but other polymer monomers may be used as the third component. Copolymers containing polymers and graft polymers with polymers having unsaturated groups can also be used. Examples of polymerizable monomers other than the compound of general formula (1) and chloromethylstyrene include styrenes such as styrene and vinyltoluene, acrylic esters such as alkyl acrylate, alkyl methacrylate, and glycidyl methacrylate; Examples include vinyl esters such as vinyl acetate, vinyl butyrate, and vinyl laurate, and unsaturated carboxylic acids such as acrylic acid and methacrylic acid. Examples of the polymer having an unsaturated group include unsaturated alkyd, styrene-butadiene rubber, butadiene rubber, and cyclized rubber. The amount of the polymerizable monomer represented by general formula (1) introduced into the polymer is preferably 1 mol% or more and 99 mol% or less. Particularly preferably, it is 10 mol% or more and 95 mol% or less. When the amount of this compound introduced becomes extremely small,
The effects of improved dispersibility, fixing properties, charging characteristics, etc. cannot be sufficiently obtained. The amount of chloromethylstyrene introduced depends on the type of monomer used and the amount introduced, and is suitably 1 mol % to 10 mol % based on the polymerizable monomer represented by general formula (1). A more preferable range is 3 mol% to 7 mol%. If the amount of chloromethylstyrene introduced into the polymer is extremely small, the effect of improving charging characteristics cannot be sufficiently obtained. On the other hand, if it is introduced beyond the above range, gelation of the polymer tends to occur, resulting in a decrease in dispersibility. It is preferable to introduce the above-mentioned third component into the copolymer of the present invention because fixing properties and the like can be adjusted. The molecular weight of the polymer used in the present invention is not particularly limited as long as it does not completely dissolve in the carrier liquid. According to conventional polymerization means, the molecular weight is 10 ³
-10 ⁵ is easily obtained, but the object of the present invention is satisfactorily achieved with the above range. Further, in the present invention, the resin forming the toner may be only a polymer containing the compound represented by the above general formula, but it may also be insoluble or swollen in the carrier liquid used in the developer of the present invention. It is also possible to use resins that can be used in combination. Examples of the resin include alkyd resin, natural resin-modified phenolic resin, polyterpene, natural resin-modified maleic acid resin, natural resin-modified pentaerythritol resin, rosin resin, styrene resin, acrylic resin, butadiene rubber, and styrene-butadiene rubber. , natural resins such as natural rubber, and synthetic resins. The resin and the polymer containing the compound represented by the above general formula are used as a mixture, and the ratio of the amounts used is determined according to the effect of improving the toner dispersibility, fixing property, and charging characteristics by the polymer. There is no particular restriction as long as it is within the range. The appropriate amount to be used depends on the properties of the polymer used and the resin used in combination, but is usually 0.01 to 100 parts by weight of the resin used in combination with 1 part by weight of the polymer. Any method can be used to produce the polymer of the present invention, and there are no particular limitations. That is, regardless of the polymerization method, it is sufficient to obtain a copolymer containing at least the compound represented by the above general formula and chloromethylstyrene as polymer components. As the polymerization method, for example, a solution polymerization method or a suspension polymerization method can be adopted. As the carrier liquid having an electrical resistance of 10 ⁹ Ω·cm or more and a dielectric constant of 3 or less used in the present invention, solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons can be used. However, from the viewpoint of volatility, safety, toxicity, odor, etc., isoparaffinic petroleum solvents are preferred. Examples of these isoparaffinic petroleum solvents include Isopar G, Isopar H, and Isopar L manufactured by Etsuso. The developer of the present invention does not necessarily need to contain a colorant, but for the purpose of visualizing the image after development,
The toner particles can contain colorants.
As the coloring agent, known pigments and dyes, or both, which have been conventionally used for liquids and liquid developers, can be used. For example, Hanzai Ero (CI11680), Benzidine Yellow G (C.
I.21090), Benzine Orange (CI21110), Fast-Stretched (CI37085), Brilliant Carmine 3B (CI16015-Lake), Phthalocyanine Blue (CI74160), Phthalocyanine Green (C.
I.74260), Victoria Blue (CI42595−
Lake), Spirit Black (CI50415), Oil Blue (CI74350), Alkaline Blue (C.
I.42770A), First Scarlet (C.
I.12315), Rhodamine 6B (CI45160), First Sky Blue (CI74200-Lake), Nigrosine (CI50415), Carbon Black, etc. In the present invention, the blending ratio of the coloring agent in the colored particles and the resin containing the polymer containing the compound represented by the above general formula as a component is arbitrarily selected.
The ratio is generally 1 part by weight of the former to 1 part by weight of the latter.
The amount is 0.01 to 100 parts by weight, preferably 0.1 to 10 parts by weight. The toner used in the developer of the present invention can be produced by a conventionally known method. An example of a manufacturing method containing a colorant will be shown below. First, a coloring agent consisting of a pigment or a dye, or both, and the resin for forming toner particles are kneaded in a solvent for the resin using a kneading machine such as a ball mill, a roll mill, or a paint shaker, and the solvent is removed by heating or the like. Remove to obtain a mixture. Alternatively, the kneaded product is poured into a liquid that does not dissolve the resin, and a mixture is obtained by reprecipitation. Alternatively, a mixture is obtained by kneading the colorant and the resin using a kneader such as a kneader or roll mill while heating the colorant to a temperature higher than the melting point of the resin, and cooling the kneader. Colored particles are obtained by dry pulverizing, wet pulverizing, or a combination of both methods. When using a resin containing the above polymer, particles with a small particle size can be easily obtained. The particle size of the colored particles is usually 1 to 0.05 μm. The toner is not limited to the above method, but any known method may be used as long as colored particles can be obtained from the colorant and the resin. The toner thus obtained is dispersed in the carrier liquid to form a liquid developer for electrostatic images. The concentration of toner in the developer is not particularly limited, but it is usually 0.001g to 100g, preferably 0.001g to 100g per 1 solvent.
The amount is 0.01g to 10g. In the present invention, additives such as conventionally known dispersants and charge control agents may be added to the developer in the same manner as in conventional methods in order to further improve the dispersibility of the toner and adjust the charge. can. The dispersant is a resin that dissolves or swells in the high electrical resistance carrier liquid used in the developer of the present invention and improves the dispersibility of the toner, such as styrene-butadiene rubber, vinyltoluene-butadiene, butadiene-butadiene rubber, etc. Synthetic rubbers such as isoprene, long chain acrylic resins and long chains such as 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, lauryl acrylate, octyl acrylate, styrene-lauryl methacrylate copolymer, acrylic acid-lauryl methacrylate copolymer Copolymers of acrylic compounds and other polymerizable monomers, polyolefins such as polyethylene, polyterpenes, etc. are used.
Other No. 4 disclosed in Japanese Patent Application Laid-open No. 54-31739
Polymers containing ammonium salt monomers are also useful. A charge control agent is one that contributes to imparting a charge to toner particles, and includes, for example, naphthenic acid, octenoic acid,
Metal salts of fatty acids such as oleic acid, stearic acid, isostearic acid or lauric acid; metal salts of sulfosuccinic acid esters;
Oil-soluble sulfonic acid metal salts shown in JP-A-52-37435, JP-A-52-37049, etc.; metal salts of phosphate esters shown in JP-B No. 45-9594;
Metal salts of abietic acid or hydrogenated abietic acid shown in -25666, alkylbenzenesulfonic acid calcium salts shown in Japanese Patent Publication No. 52-2620, Japanese Patent Application Publications No. 52-107837, No. 52-38937, No. Metal salts of aromatic carboxylic acids or sulfonic acids, nonionic surfactants such as polyoxyethylated alkylamines, lecithin, linseed oil, etc., as shown in 1981-90643, JP 57-139753, etc. Oils and fats, polyvinylpyrrolidone, organic acid esters of polyhydric alcohols, oil-soluble phenolic resins shown in Japanese Patent Publication No. 46-3716, phosphate ester surfactants shown in Japanese Patent Publication No. 57-210345,
Examples include sulfonic acid resins shown in No. 56-24944. It is particularly advantageous to add a charge control agent having a metal salt to the developer of the present invention, since a developer containing a clearly positively charged toner can be obtained. The developer of the present invention can be used for photoreceptors using well-known organic photoconductors or inorganic photoconductors. The developer of the present invention can also be used to develop electrostatic latent images produced by means other than photosensitivity, such as by charging a dielectric material with a charging needle. Organic photoconductors include a wide variety of well-known organic photoconductors. A specific example is Research Disclosure #10938 (1973).
There are substances described in the paper entitled "Electrophotographic Elements, Materials and Processes" from page 61 onward of the May issue. Examples of those that are in practical use include electrophotographic photoreceptors made of poly-N-vinylcarbazole and 2,4,7-trinitrofluoren-9-one (US Pat. No. 3,484,239), and poly-N-vinylcarbazole. sensitized with a pyrylium salt dye (Japanese Patent Publication No. 48-25658), an electrophotographic photoreceptor whose main component is an organic pigment (Japanese Patent Publication No. 47-37543), and a eutectic complex consisting of a dye and a resin as its main component. There is an electrophotographic photoreceptor (Japanese Patent Application Laid-Open No. 10785-1983). As the inorganic photoconductor used in the present invention, electrophotography ("Electrophotography" by RM Schaffert,
Published by Focal Press (London) (1975)) 260 pages ~
Various inorganic compounds disclosed on page 374 are representative. Specific examples include zinc oxide, zinc sulfide, cadmium sulfide, selenium, selenium-tellurium alloy, selenium-arsenic alloy, selenium-tellurium-arsenic alloy, and the like. Next, a method for synthesizing the polymer used in the present invention will be shown using a synthesis example, but the present invention is not limited thereto. Synthesis Example 1 300 equipped with a stirrer, reflux condenser, and nitrogen inlet tube
28.7 g of styrene monomer in a ml glass container,
Add 22.3 g of diethylaminomethylstyrene, 0.6 g of chloromethylstyrene, 346 mg of azobisisobutyronitrile, and 75 g of toluene, and polymerize at 80°C for 8 hours while stirring under a nitrogen stream to obtain a solution containing the copolymer. I got it. Add this to methanol 2.5
The precipitated white polymer was collected and dried at room temperature under reduced pressure using a vacuum pump. The obtained polymer was dissolved in 100 g of chloroform, and 2.5 g of methanol was added.
The polymer was reprecipitated by pouring into the solution, and 21.3 g of a purified white powder polymer was obtained by drying in the same manner as above. Synthesis Examples 2 to 7 The polymers listed in Table 1 were produced in the same manner as in Synthesis Example 1.

[Table] Synthesis Examples 8 to 10 (Comparative Examples) For comparison, the copolymers shown in Table 2 were produced in the same manner as in Synthesis Example 2.

[Table] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. Example 1 As a pigment, 3.5 parts by weight of carbon black (Mitsubishi #40, manufactured by Mitsubishi Kasei Corporation) and 3.5 parts by weight of the copolymer of Synthesis Example 1 were used.
Add 17.3 parts by weight of toluene and 70 parts by weight of glass beads to paint sheaker (Toyo Seiki Co., Ltd.).
The mixture except for the glass beads was poured into Isopar H (manufactured by Etsuso Corporation) for 90 minutes, and the precipitate (14 parts by weight) was filtered out. 1 part by weight of the filtered precipitate was mixed with 10 parts by weight of Isopar H solution (5% by weight) of Solprene 1205 (styrene-butadiene rubber, manufactured by Asahi Kasei Corporation), and mixed with 25 parts by weight of glass beads in a paint shaker at 90% by weight. Mixed for a minute. Next, 1 part by weight of the above dispersion was added to zirconium naphthenate.
It was diluted with 100 parts by weight of Isopar H containing 10 ^-4 mol/ to obtain liquid developer No. 1 for electrostatic images. The obtained developer showed clear positive chargeability and was a liquid developer with excellent dispersibility and fixing properties. Next, the amount of charge on this liquid developer was measured using the apparatus disclosed in JP-A No. 57-58176. The results are shown in Table 3. Example 2 A liquid developer was prepared in the same manner as in Example 1, except that the polymers of Synthesis Examples 2 to 7 were used instead of the copolymer of Synthesis Example 1.
Liquid developer No. 1 with good dispersibility, fixing properties, and charging characteristics.
2 to No. 7 were obtained. Table 3 shows the measurement results of the amount of charge. Comparative Example Using the copolymers of Synthesis Examples 8 to 10 (comparative examples), the same operations as in Example 1 were carried out to obtain Comparative Liquid Developer No.
Got 8-10. Table 3 shows the measurement results of the amount of charge.

[Table] "Effects of the Invention" As is clear from Table 3, all of the liquid developers No. 1 to No. 7 of the present invention exhibit clear positive chargeability,
It has a satisfactory amount of charge. On the other hand, developer Nos. 8 to 10 of Comparative Examples had unclear charge polarity and insufficient charge amount. Moreover, it was apt to cause flocculation and sedimentation.

Claims (1)

[Scope of Claims] 1. A resin containing at least one polymerizable monomer represented by the following general formula (1) and chloromethylstyrene as a copolymer component, which has an electrical resistance of 10 ⁹ Ω-cm or more. A liquid developer for electrostatic images, which is dispersed in a carrier liquid having a dielectric constant of 3 or less. embedded image In the formula, A represents a hydrogen atom or a methyl group, and B represents any of the following general formulas (2), (3), (4), (5), and (6). [Chemical Formula] [Chemical Formula] [Chemical Formula] [Chemical Formula] In the formula, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group. In that case, R ₁ and R ₂ may be the same or different. Also
A ring can also be formed by R ₁ and R ₂ and the nitrogen atoms described in general formulas (2) to (6). In that case, the ring may contain carbon, oxygen, and sulfur as constituent elements. The total number of carbon atoms in R ₁ and R ₂ is 36 or less.
n represents a positive integer from 1 to 6.