JPS6334463B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electrostatic recording medium or a recording medium that retains a transferred electrostatic image using an electrostatic image transfer type electrophotographic process (TESI method). It is characterized in that it is produced by applying a composition consisting of a hydrolyzate of a silane compound and a condensation catalyst or a curing agent to the surface of a conductive support or via a non-photosensitive insulator, and then condensing and curing the composition. It relates to electrostatic image recording media with excellent recording performance and mechanical performance. In particular, recording methods in which a toner image is formed on an electrostatic image recording medium, the image is transferred to plain paper, and then cleaned and used repeatedly, such as copying machines, facsimile receivers, printers, etc. that use plain paper as the hard copy base paper. It is useful as a transcription master. The hard copy process on plain paper using a repeatable transfer master consists of (1) electrostatic image recording, (2) toner development, (3) transfer, and (4) cleaning of the recording medium. The required performance for the recording medium is (1) electrostatic image recording performance...... suitable surface and volume resistivity, dielectric constant, high dielectric breakdown strength, (2) durability of the recording medium...
Corona deterioration resistance, scratch resistance, abrasion resistance, (3)
Although the recording performance does not change due to humidity, it is difficult for conventional recording media to simultaneously satisfy such performance, and there is a strong desire to develop a recording media with higher performance. The biggest challenge for materials for transfer masters is to satisfy the durability of the recording medium while also achieving other properties. The TESI method does not perform toner development transfer or cleaning on the photoconductor, which is the main cause of mechanical damage in the hard copy manufacturing process, and removes the transfer master due to mechanical damage even though the photoconductor still has its lifespan. The drawbacks of the discarded xerography method (Carlson method) can be improved. From this point of view, the transferred electrostatic image recording medium used in the TESI method needs to have excellent mechanical durability.Achieving this performance will not only extend the life of the master in copiers and printers, but also reduce the amount of maintenance required. The device can be easily handled, and hard copies can be obtained at low cost. The TESI method is also promising for preserving environmental health by preventing toxic photoconductors from transferring to copy paper or scattering indoors, which is a problem with the xerography method. In order to achieve such required performance, much effort has been put into developing insulating dielectric materials provided on conductive supports or protective film materials provided on the dielectrics. Various synthetic polymers are commonly used as such materials, and inorganic compounds such as oxides, fluorides, chlorides, sulfides, carbonates,
Nitrates, sulfates, etc. have been used or proposed. However, the materials that have been proposed so far have poor scratch resistance, abrasion resistance, and mechanical durability, and have not yet exhibited satisfactory performance as transfer masters that are used repeatedly. Silicon compounds have been used as one such material. Silane compounds, polymers of silane compounds, silica, and the like have been proposed, but conventional structural materials have only improved recording performance and surface release performance, but have not improved mechanical durability. A more detailed explanation is as follows. There are examples of using silanol compounds obtained by hydrolyzing organofunctional silane compounds (silane coupling agents) such as vinyltriethoxysilane and γ-glycidoxypropylmethoxysilane; The compound is only a modifier for inorganic fine powder and is not used as a structural material for recording bodies. This is clear from the explanation that using a large amount of silanol compounds is undesirable because unreacted substances remain and performance deteriorates. Polymers of silane compounds are rarely proposed with a specific structure; organopolysiloxane, silicone resin, silicone oil, etc.
It has only been proposed as silicone rubber. That is, the main body is a long chain polymer having polysiloxane bonds, and there is no mention of a specific three-dimensional condensation polymer used in the present invention.
It barely suggests a crosslinked silicone rubber, and it is nothing more than a two-dimensionally crosslinked rubber elastic body. In addition, silica has only been proposed as an additive, and does not provide a durable structure that improves the surface performance of a recording medium. For example, alkylated silica in which silanol groups on the surface of silica are substituted. The present invention is a three-dimensional condensate of silicon compounds that has not been discussed in the past, and uses specific raw materials to synthesize and use a specific structure, which is difficult to achieve with conventional materials. For the first time, it has become possible to achieve both physical durability and recording performance. That is, the present invention provides the method of forming (A) the general formula (However, X ¹ is

^a _hydrolyzate , silanol and/or An electrostatic image recording material used for electrostatic recording or electrostatic image transfer type electrophotography, characterized in that it is provided with a silicon compound layer comprising a mixture of a compound containing a siloxane group and an epoxy compound, and (B) a curing agent. . The electrostatic image recording material of the present invention uses a conductive support. The support may be a drum, a sheet, a flexible film, etc., and may be conductive itself or may be an insulator with a conductive material adhered or laminated on its surface. Examples of the conductive support include drums and foils made of aluminum, copper, iron, zinc, or stainless steel. The insulating support is made of glass, polymeric material, etc., and methods for making it conductive include laminating metal foils, applying a thin layer of metal or metal compounds, and coatings made of conductive polymers or compound compositions of conductive compounds. Coaching, etc. Methods for depositing metals and metal compounds include vacuum evaporation, electron beam evaporation, and sputtering. Depending on the conditions under which the electrostatic image recording medium is used, it may be necessary to control the resistance value of the conductive layer within a certain range, for example, within a fairly narrow range of surface resistance between 10 ² and 10 ⁸ Ω/□. This can be adjusted by adjusting the amount of the metal or metal compound deposited, or by taking into account the form of the conductive layer, such as depositing it in an island or striped form if the resistance value is high, and a deposition method such as sputtering is useful. Examples of metals and metal compounds that can be used include aluminum, copper, palladium, platinum, silver, rhodium, indium oxide, chalcogen compounds, tin, tin oxide, and indium oxide doped with tin or tin oxide. When producing a flexible electrostatic image recording medium, polymer films are preferably used such as polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6
Films such as polyester polymers such as naphthalene dicarboxylate, polyolefins such as polypropylene, polyamides such as nylon 12, polyimides having five-membered ring imide bonds in their polymer chains, and polycarbonates can be used. A silane compound/hydrolyzate composition is applied to the conductive support directly or via a non-photosensitive insulator and cured by condensation, but this non-photosensitive insulator is
Organic or organometallic polymers can be used, including (1) polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6 naphthalene dicarboxylate, ethylene glycol and 2,2 alkyl-substituted 1,3-propanediol and one or two kinds of polymers. Polyester polymers or copolymers such as ester copolymers with carboxylic acids and unsaturated polyesters; (2) Olefin polymers or copolymers such as polyethylene, polypropylene, and ethylene/vinyl acetate copolymers; (3) Polystyrene and styrene copolymers such as styrene-butadiene copolymers, (4) cellulose derivatives such as cellulose acetate, (5) vinyl chloride such as polyvinyl chloride, chlorinated polyvinyl chloride, or vinyl chloride-vinyl acetate copolymers. copolymer, (6) polyimide having a five-membered ring imide bond in the polymer main chain, polyamideimide, (7)
Polyvinyl acetate, (8) Fluororesins such as polytetrafluoroethylene, polytrifluorochloroethylene, polyvinylidene fluoride, (9) vinylidene chloride/vinyl chloride copolymer, vinylidene chloride/alkyl acrylate copolymer, etc. vinylidene chloride copolymer, (10) at the end
Polyurethane resin obtained from polyester or polyether with OH group and polyfunctional isocyanate, (11) acrylic ester, methacrylic ester polymer or copolymer, (12) epoxy resin,
(13) Phenol resin, (14) Melamine resin, (15)
Urea resin, (16) polycarbonate, (17) polyvinyl acetal, etc. can be used. In the silicon compound layer used in the present invention, a compound containing an epoxy group and a silanol and/or siloxane group in its molecule has the general formula (However, X ¹ is

A compound represented by a group containing the formula: where R ¹ is a C _1-6 alkyl or aryl, n is 2 or 3, a is an integer from 0 to 2, and b is an integer from 1 to 6) is used.

A group containing [Formula] is, for example,

[Formula] (R ² is hydrogen or methyl),

[Formula] etc. Specific representative examples include γ-glycidoxypropyltrialkoxysilane, γ-glycidoxypropylalkyldialkoxysilane, β(3,
A hydrolyzate of 4-epoxycyclohexyl)ethyltrialkoxysilane can be mentioned. Silanol and/or used in the present invention
Alternatively, the compound containing a siloxane group refers to a hydrolyzate of 4-alkoxy silicon, and a compound having the general formula

[expression] or

[Formula] (However, X ² is a C _1-6 alkyl, halogen _, vinyl, aryl, methacryloxy, mercapto, amino, H ₂ N-(CH ₂ ) _b ^-NH- group, alkyl or aryl, n is 2 or 3, b is 1
(an integer of 6 to 6). Specific examples include methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate, n-butyl silicate, sec-butyl silicate, tert-butyl silicate, methyltrialkoxysilane, vinyltrialkoxysilane, vinyltriacetoxysilane, vinyl Trialkoxyalkoxysilane, phenyltrialkoxysilane, methacryloxypropyltrialkoxysilane, chloropropyltrialkoxysilane, alkyltriacyloxysilane, γ-aminopropyltrialkoxysilane, N-β(aminoethyl)γ-aminopropyltrialkoxy Hydrolysis of silane, γ-mercaptopropyltrialkoxysilane, dialkyldialkoxysilane, alkylphenyldialkoxysilane, diphenyldialkoxysilane, N-β(aminoethyl)γ-aminopropylmethyldialkoxysilane, alkyltrichlorosilane You can give things. Hydrolysis of these silicon compounds is produced by adding and stirring water or an acidic aqueous solution such as hydrochloric acid or sulfuric acid. This is usually carried out by adding acidic water to the silicon compound all at once or gradually. During hydrolysis, alcohol, alkoxy alcohol, organic carboxylic acids such as acetic acid, etc. are produced, so hydrolysis can be carried out without a solvent. Alternatively, the silicon compound can be mixed with a suitable solvent and then hydrolyzed. Usually, the obtained hydrolyzate solution is used as it is, but depending on the purpose, after hydrolysis is performed without a solvent, an appropriate amount of the generated alcohol, etc. is removed by heating and/or under reduced pressure before use. It is also possible to substantially replace the solvent by subsequently adding a suitable solvent. As the solvent, various solvents such as alcohols, esters, ethers, ketones, halogenated hydrocarbons, and aromatic solvents such as toluene can be used depending on the purpose, and mixed solvents can also be used if necessary. In the case of two or more types, they may be hydrolyzed individually and then mixed, or two or more types may be mixed and then hydrolyzed. The epoxy compounds used in the present invention include:
It is widely used for paints, casting, etc.
For example, polyolefin-based epoxy resins synthesized by the peroxidation method, polyglycidyl esters obtained from cyclopentadiene oxide or hexahydrophthalic acid and epichlorohydrin, polyhydric phenols such as bisphenol A, catechol, and resorcinol, or (poly)ethylene glycols, Poly)propylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diglycerol,
Polyglycidyl ethers obtained from polyhydric alcohols such as sorbitol and epichlorohydrin,
Cyclic epoxy resins, epoxidized vegetable oils, epoxy novolak resins obtained from novolac-type phenolic resins and epichlorohydrin, epoxy resins obtained from phenolphthalein and epichlorohydrin, and acrylate monomers such as glycidyl methacrylate and methyl methacrylate, or styrene, etc. Examples include copolymers of Although various epoxy curing agents can be used as the curing agent of the present invention, an aluminum compound having the structure shown below is particularly effective in achieving the object of the present invention. The compound has the general formula Al・Y _n・Z _(3-n) [However, Y is OL (L is C _1-6 alkyl), Z is the general formula M ¹ COCH ₂ COM ² or M ³ COCH ₂ COOM ⁴
(M ¹ , M ² , M ³ , M ⁴ ) is at least one ligand derived from a compound represented by C _1-6 alkyl), and m is an integer of 0 to 3. be. ] is a compound represented by Various compounds can be mentioned, but from the viewpoint of solubility in the composition, stability, effect as a curing catalyst, etc., the following are preferable:
Aluminum iso-propoxide, aluminum ethoxide, aluminum tert-butoxide, aluminum acetylacetonate, aluminum bis-ethylacetoacetate-mono-acetylacetonate, aluminum di-n-butoxide-monoethylacetoacetate, aluminum di- These include iso-propoxide-mono-methylacetoacetate, aluminum-di-sec-butoxide-mono-ethylacetoacetate, aluminum-di-methoxide-mono-methylacetoacetate, and the like. It is also possible to use a mixture of two or more of these. The amount of curing agent added is per 1 part by weight of the above mixture.
0.0001 to 0.5 parts by weight, particularly preferably 0.0005 to 0.2
The weight part is appropriate; if it is less than this, the curing will be insufficient, while if it is more than this, defects such as a decrease in the transparency of the coating film or resin and a decrease in water resistance will occur. Further, colloidal silica can be blended within a range that can maintain the properties of the silicon compound. An effective colloidal silica is a colloidal solution in which silicic anhydride is dispersed in water or an alcoholic solvent, which is produced by a well-known method and is commercially available. For purposes of this invention, average particle sizes of 5 to 100 millimicrons are useful. It is also possible to use surfactants in the composition of the present invention in order to improve the flow during application and the smoothness of the coating film, and in particular, surfactants such as block or graft copolymers of dimethylsiloxane and alkylene oxide can be used. is valid. Furthermore, curing catalysts and additives (e.g., adhesion promoters, PH regulators, plasticizers, stabilizers, antioxidants, ultraviolet absorbers, lubricants, thickeners, antifoaming agents, colorants, etc.) are added as necessary. It is also permissible to use them in combination. The thickness of the silicon compound layer is not particularly specified, but the composition may vary depending on the application to electrostatic recording.
Control the film thickness so that it does not reduce resolution or wear resistance. Normally, 0.5μ to 50μ is desirable. If it is too thin, the abrasion resistance will not be sufficient, and if it is too thick, there is a risk of poor image quality, long curing time, reduction in flatness, and occurrence of cracks, which is not preferable. As a means of applying such a silicon compound layer, commonly used coating methods such as brush coating, dip coating, knife coating, roll coating, spray coating, flow coating, and rotation coating (spinner, whaler, etc.) can be easily used. It is. The electrostatic image recording material of the present invention may be subjected to a known surface treatment or provided with a surface modification layer such as a primer, if necessary, to improve adhesion between each layer. The electrostatic image recording material obtained in the above manner has excellent hardness, particularly abrasion resistance, and scratch resistance, and is hardly scratched even when rubbed strongly with a hard material such as steel wool. Since there is no deterioration in appearance due to scratches during processing, image formation, and use, which was a problem, durability and commercial value are significantly improved. It also has excellent cleaning properties, chemical resistance, and moisture resistance, and does not substantially impede the practical properties of electrostatic recording. Further, when the recording medium is made of a flexible substrate, this is a more preferred embodiment since the protective film made of the silicon compound of the present invention has extremely excellent flexibility. Since continuous processing and continuous use are possible, it is possible to produce an electrostatic image recording medium with high workability and practicality. Examples will be described below, but the invention should not be limited to these. Note that parts and percentages in the examples are by weight unless otherwise specified. Example 1 On a biaxially stretched polyethylene terephthalate film (“Lumirror” manufactured by Toray Industries, Inc.) with a thickness of 100μ,
Palladium (99.99% purity) was deposited by cathodic sputtering. The surface electrical resistance of this film was 5×10 ⁶ Ω/□. The cathode sputtering method uses a palladium plate as the cathode, a water-cooled metal drum as the anode, runs the film while keeping it in close contact with the drum, and applies a DC voltage of 4 kV with a distance of 25 mm between the two electrode plates. Sputtering was performed in a low vacuum atmosphere of argon gas on the order of ^-2 Torr. An insulating layer with a thickness of 7 μm made of a saturated polyester resin and fine silicon oxide powder was formed on the palladium film of the film, thereby producing electrostatic image recording member No. 1. A hydrolyzate obtained by hydrolyzing γ-glycidoxypropylmethyldiethoxysilane with a 0.01N aqueous hydrochloric acid solution (contains 61% solids) on the insulating layer.
100 parts, 45 parts of "Epicote" 828 (manufactured by Ciel Chemical, epoxy compound), methanol-dispersed colloidal silica ("methanol silica sol", manufactured by Nissan Chemical Co., Ltd.),
Solid content concentration 30%) 150 parts, aluminum acetylacetonate 9 parts, silicone surfactant 0.32
and isopropyl alcohol/as a solvent.
A paint containing 200 parts of a 2/1 mixture of n-butyl alcohol was applied to a solid coating thickness of 3 μm, dried at 150°C for 2 minutes, and cured to form an electrostatic image with good flatness. Recording body No. 2 was produced. The obtained performance was as shown in Table 1. The test method is as follows. (The same applies to the following examples.) (1) Abrasion resistance Rub with steel wool #0000 to examine scratch resistance. The judgment was made as follows. A: No scratches even if rubbed strongly. B: If it is rubbed quite strongly, it will be slightly scratched. C: Even weak friction causes scratches. (2) Electrostatic properties After being charged with a corona charger, the attenuation of the surface potential is measured and the electrostatic properties are evaluated. (3) Flexibility (bending test) Laminated films are wrapped around cylinders of various diameters with the silicon compound layer on the outside, and the flexibility is expressed as the diameter at which a crack occurs in the silicon compound layer. The electrostatic image recording material of the present invention had good electrostatic properties, and its abrasion resistance and durability were significantly improved compared to No. 1. Regarding the chemical resistance of the surface, no abnormality was observed after 24 hours of contact with hydrocarbons (toluene, xylene, ligroin) and halogenated hydrocarbons (chloroform, carbon tetrachloride, trichlene). The electrostatic image recording material was electrostatically recorded using a multi-pin electrode head and then developed, and used as a facsimile master film. No. 2 recording material of the present invention does not cause scratches even when contacted with the electrode head.
It has excellent durability and can produce clear images even after repeated use. Also, the image quality was good under 85%RH/humidity. On the other hand, the No. 1 recording material had poor abrasion resistance, and its durability after repeated use became a practical problem. Instead of the above silicon compound layer, a polydimethylsiloxane resin layer with terminal silanol is added to the thickness.
When 2μ was applied, the abrasion resistance was not sufficient and the image became smudged due to repeated use, which caused problems in use. Example 2 A primer layer made of an acrylic ester copolymer was provided on the palladium layer prepared in the same manner as in Example 1, and then 120 parts of butyl silicate,
A hydrolyzate consisting of 60 parts of ethanol and 31.2 parts of a 0.1N aqueous hydrochloric acid solution, 50 parts of a hydrolyzate obtained by hydrolyzing γ-glycidoxypropyltrimethoxysilane with a 0.01N aqueous hydrochloric acid solution, "Epicote" 828 (Ciel Chemical epoxy compound) 45 parts, methanol-dispersed colloidal silica (Nissan Chemical Co., Ltd. "Methanol Sol", solid content concentration 30%) 130 parts, isopropyl alcohol/toluene = 1/1 mixture 50 parts, silicon oxide fine powder An electrostatic image recording medium was prepared by adding and blending 25 parts of the paint to a solid distribution layer thickness of 8 μm. When used as a facsimile master film in accordance with Example 1, it had excellent durability and could be used repeatedly.

[Table] Example 3 Palladium was deposited on a biaxially stretched polyethylene terephthalate film ("Lumirror" manufactured by Toray Industries, Inc.) having a thickness of 100 μm by cathodic sputtering according to Example 1. The surface electrical resistance of this film was 1.1×10 ⁴ Ω/□. After applying epoxy/polyamide adhesive to a solid content thickness of 0.3 μm on the palladium membrane of the film, polycarbonate resin (A made by Idemitsu Petrochemical Co., Ltd.) was applied.
-2200), 10 parts of silicon oxide fine powder, and 900 parts of a tetrahydrofuran/toluene = 10/2 mixture to form an insulating layer with a thickness of 5μ, and electrostatic image recording material No.
3 was produced. After providing a primer layer made of an acrylic ester copolymer on the insulating layer, γ-
glycidoxypropyltrimethoxysilane
To 100 parts of the hydrolyzate obtained by hydrolysis with 0.01N hydrochloric acid aqueous solution (containing 58% solid content), 55 parts of "Dinacol" 320 (an epoxy compound manufactured by Nagase Sangyo Co., Ltd.) and 10 parts of aluminum acetylacetonate. A paint containing 0.30 parts of a silicone surfactant and 230 parts of a 2/1 mixture of isopropyl alcohol/n-butyl alcohol was applied to a solid coating thickness of 2μ, dried, and cured. Electrostatic image recording material No. 4 with good flexibility and flatness was produced. The above-mentioned electrostatic image recording material is superimposed on a photosensitive plate having a transparent conductive layer and a photoconductive photosensitive layer containing cadmium sulfide sequentially provided on a glass plate, and patterned light exposure and negative charging are simultaneously performed. An electrostatic latent image was formed on the surface. Next, the electrostatic latent image was visualized using liquid toner and then transferred to plain paper to obtain a copied image. The surface of the electrostatic image recording member was cleaned of residual toner and used repeatedly. Both No. 3 and No. 4 electrostatic image recording materials had good electrostatic properties, and clear images with high density were obtained even after a small number of uses. As the number of times it was used increased, scratches appeared on the surface of the No. 3 recording medium, and the image became smudged.
Recording material No. 4 of the present invention had excellent durability, and no deterioration in image quality was observed even after repeated use. Furthermore, the chemical resistance and toner cleaning properties were good, and there were no practical problems. In addition, the No. 4 recording medium had excellent flexibility, so it was easy to handle and had good workability. Furthermore, since toner is not applied directly to the photosensitive layer of the photosensitive plate, the life of the photosensitive plate is extended and maintenance becomes easier.

Claims (1)

[Claims] 1. Directly or through a non-photosensitive insulator on a conductive support, (A) general formula (However, X ¹ is a group containing [formula], R ¹ is C _1-6 alkyl or aryl, n is 2 or 3, a is 0-2, and b is an integer of 1-6). used in electrostatic recording or electrostatic image transfer type electrophotography, characterized in that it is provided with a silicon compound layer consisting of a mixture of a compound containing a silanol and/or a siloxane group, and an epoxy compound, and (B) a curing agent. Electrostatic image recording medium.