JPH0497156A - Conductive substrate and electrostatic recording body using same - Google Patents

Abstract

PURPOSE:To enhance waterproofness of the conductive layer without changing good recording characteristics by incorporating an acrylic type copolymer of a specified vinyl monomer and at least one of other vinyl monomers and a conductive whisker in the conductive layer. CONSTITUTION:The conductive layer contains the acrylic type copolymer of the vinyl monomer represented by formula I and at least one of the other vinyl monomers. In formula I, R1 is H or methyl; R2 is alkylene; each of R3 - R5 is 1 - 4 C alkyl or benzyl; and X is Cl, Br, CH3SO4, or C2H5SO4, thus permitting the obtained conductive substrate to be small in humidity dependency in a wide environmental conditions and good in recording characteristics and the electrostatic recording body using this conductive substrate to have such characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrically conductive support, and more specifically, 21! The present invention provides a conductive support in which the water resistance of the conductive layer is improved while maintaining the conductivity required for the conductive layer, and an electrostatic recording medium using the same.

[Conventional technology]

Conventionally, in electrophotographic photoreceptors and electrostatic recording papers, conductive supports have been used as supports for providing the recording layer (photoconductive layer in the case of electrophotographic photoreceptors, dielectric layer in the case of electrostatic recording materials). It is used.

By the way, electrostatic recording methods using electrostatic recording materials have been used in various fields such as facsimile, drafting, newspaper proofing, and official document recording. Compatible devices have been developed, and as a result, its uses have rapidly expanded, and it has become popular, particularly in design-related, event-related, and public notice-related fields because color copies can be easily obtained. Against this background, electrostatic recording media are required to have excellent water resistance so that they can be used outdoors and to have excellent recording properties even under harsh environmental conditions.

However, conventional electrostatic recording materials have amino groups on a water-resistant support such as paper, resin film, or fabric that has been previously treated to make it waterproof, as disclosed in JP-A No. 61-264345. A conductive support provided with a conductive layer containing a conductivity imparting agent made of a cationic polymer electrolyte is used.

However, such conventional electrostatic recording materials are satisfactory in that the electrical resistance of the conductive layer is less susceptible to changes in humidity under a wide range of environmental conditions, that is, has little humidity dependence. Since the cationic polymer electrolyte contained in the layer is water-soluble, when used outdoors, as mentioned above, exposure to rain causes the conductive layer to gradually dissolve and the recording layer to peel off. Put it away. Therefore, an electrostatic recording material having excellent recording properties and sufficient water resistance to be used outdoors has not yet been developed.

[Problems to be Solved by the Invention] In view of the above circumstances, the present invention provides a conductive support in which the water resistance of the conductive layer is improved while maintaining good recording characteristics, and an electrostatic recording medium using the same. It is something to do.

Means for Solving CRB] The present invention provides a conductive support in which a conductive layer is provided on at least one side of the support, in which the conductive layer has the following general formula (1) % formula % (wherein R5 is Hydrogen atom or methyl group, R2 is an alkylene group, R3+ R4 and R7 are an alkyl group or benzyl group having 1 to 4 carbon atoms, X is Cj2, Br, C
It represents H3SO4°C2H550. ) and an acrylic copolymer of at least one other polymerizable vinyl monomer; and a conductive whisker; This is an electrostatic recording material in which a recording layer is provided on a conductive layer of a magnetic support.

The polymerizable vinyl monomer represented by general formula (1) in the present invention includes, for example, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate, etc. Aminoalkyl (meth)acrylates obtained by reacting dialkylaminoalkyl (meth)acrylates with alkylating agents such as methyl chloride, ethyl chloride, benzyl chloride, methyl bromide, ethyl bromide, dimethyl sulfate, diethyl sulfate, etc. It is a quaternary ammonium salt. In addition, other polymerizable vinyl monomers that form a copolymer with the quaternary ammonium salt of the aminoalkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate,
Acrylate, alkyl (meth)acrylate such as j-butyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (
Examples include, but are not limited to, meth)acrylamide, acrylonitrile, vinyl acetate, styrene, α-methylstyrene, and vinyltoluene.

The acrylic copolymer used in the present invention is a copolymer consisting of a polymerizable vinyl monomer represented by the general formula (I) as described above and at least one other polymerizable vinyl monomer, and is a copolymer made of a polymerizable vinyl monomer represented by the general formula (I) as described above and at least one other polymerizable vinyl monomer. It is manufactured by a polymerization method. At this time, in the composition of the copolymer, the general formula (1
) has a polymerizable vinyl monomer component of 10 to 45
It is preferably 25 to 40% by weight, particularly preferably 25 to 40% by weight. If the proportion of the polymerizable vinyl heptamer component represented by the general formula (I) exceeds 45%, it may become difficult to obtain sufficient water resistance or the image properties may deteriorate, such as a decrease in image density in a high humidity environment. Deterioration is likely to occur. On the other hand, if the ratio is less than 10%, image problems such as image density unevenness are likely to occur in a low humidity environment.

The conductive whiskers used in the present invention are acicular (
A conductive material with a fibrous crystal structure.
Compared to conventional conductive powder, it is possible to obtain the same effect with a small amount of use. Specifically, for example, whiskers such as potassium titanate, silicon carbide, and aluminum borate can be mixed with tin oxide, antimony oxide, Examples include those subjected to doping treatment with gold, silver, etc.

Among these, alkali metal titanates such as potassium titanate are preferred because they provide good whiteness. In addition, the size of the conductive whisker is such that the long sleeve diameter (fiber length) in the longitudinal direction of the needle crystal is 0.5 to 100 μm.
In order to form a uniform conductive layer, it is particularly preferable that the short axis diameter (fiber diameter) in the width direction is 0.1 to 1 μm. Furthermore, the specific resistance of the conductive whisker is 104Ω・1
The following is preferable in order to obtain excellent conductivity.

The conductive layer in the present invention uses an acrylic copolymer as described above as a main component as a binder resin component constituting the conductive layer, and conductive whiskers as described above are dispersed in the acrylic copolymer. It is something. At this time, the blending ratio of the acrylic copolymer and the conductive whisker is 1 part by weight of the conductive whisker per 100 parts by weight of the acrylic copolymer.
The amount is preferably 5 to 150 parts by weight. If the amount of conductive whiskers is too small, it will occur in a low humidity environment, and if it is too large, it will occur in a high humidity environment. In both cases, problems such as image density and image unevenness will occur, which will interfere with image formation. It is something.

In addition, in the conductive layer, if necessary, conductive substances conventionally used in the conductive layer such as carbon black, graphite, tin oxide, titanium oxide, zinc oxide, antimony oxide, gold, silver, copper, nickel, etc. In addition, inorganic pigments such as silica, aluminum hydroxide, aluminum oxide, kaolin, talc, mica, and calcium carbonate, and organic pigments such as cellulose powder, polyethylene powder, and polypropylene powder can be added. . Furthermore, in addition to the acrylic copolymer specified above, the conductive layer of the present invention may include other acrylic or styrene copolymers that are compatible with the acrylic copolymer.
A conductive layer can also be formed by adding and dispersing a polyester resin or the like.

The conductive layer having such a structure has a surface resistance value of 1.
．． It is desirable that the resistance is 0x10' to 1.0x109Ω.

Examples of the support in the present invention include paper, synthetic paper, nonwoven fabric, various resin films, fabric, and leather, but are not particularly limited. For electrostatic recording materials that are required to have severe water resistance so as to withstand outdoor use, it is preferable to use paper, resin film, fabric, or the like that has been treated to be water resistant by impregnating or coating with a resin as a support.

The conductive support of the present invention is one in which the above-mentioned conductive layer is provided on at least one side of the above-mentioned support.

Further, the electrostatic recording medium of the present invention has a recording layer provided on the conductive layer of the above-mentioned conductive support. In the case of a conductive support in which conductive layers are provided on both sides of the support, the recording layer is provided only on the conductive layer on one side. Here, as the recording layer, various organic solvent-soluble resins having a high insulation resistance and functioning as a dielectric layer of an electrostatic recording medium can be used, such as polyester, polycarbonate, polyamide, polyurethane, (meth)acrylic resin, etc. Examples include resins, styrene resins, butyral resins, olefin resins, silicone resins, and fluororesins.

Note that, if necessary, inorganic pigments and organic pigments used in the above-mentioned conductive layer can be added and used.

In the present invention, to provide the conductive layer and the recording layer, for example, water, methanol, ethanol, toluene, acetone,
A paint prepared by dissolving or dispersing the above materials in a solvent such as methyl ethyl ketone or ethyl acetate is coated with an air knife coater,
Roll coater, wire bar coater, spray coater, fountain coater, reverse roll coater
It can be provided by coating and drying.

In the conductive support and electrostatic recording material of the present invention, if necessary (i) if a conductive layer is provided on only one side, the conductive layer between the support and the conductive layer and/or the conductive layer of the support; (ii) When conductive layers are provided on both sides of the support, a barrier layer can be provided on at least one side between the support and the conductive layer. The barrier layer is made of, for example, styrene-butadiene copolymer, acrylic/acrylic acid ester copolymer, styrene/acrylic copolymer,
Various emulsion-based resins such as vinyl acetate/acrylic copolymer, vinyl chloride, vinyl chloride/vinyl acetate copolymer, and the like are suitable, but various known resins can be used without being limited thereto. Furthermore, the inorganic pigments, organic pigments, and conductive pigments used in the conductive layer described above can be used as necessary.

The conductive support of the present invention is used not only for electrostatic recording materials as described above, but also for, for example, electrophotographic photoreceptors, original plates for electrophotographic lithographic printing, and the like.

(Example) Next, a detailed explanation will be given with reference to Examples. Note that all parts indicating the formulations represent parts by weight.

Example 1 Using high-quality paper with a basis weight of 50 g/rK as a support, a conductive layer paint having the following composition was applied to one side of the support.
After drying, a conductive layer having a coating amount of 5 g/rrf was provided to prepare a conductive support of the present invention.

(Example 3) Example 2 As the acrylic copolymer used in the conductive layer paint in Example 1, a polymerizable vinyl monomer represented by the general formula (I)/methyl methacrylate/n-butyl A conductive support of the present invention was produced in exactly the same manner as in Example 1, except that a copolymer having a methacrylate copolymerization ratio of 30:35:35 was used.

Examples 3 to 6 Example 1 except that the following compound was used as the polymerizable vinyl monomer component represented by general formula (1) of the acrylic copolymer used in the conductive layer paint in Example 1. The conductive support of the present invention was produced in exactly the same manner as described above.

(Example 4) (Example 5) (Example 6) (The following is a blank space) Example 7 A coating amount of 8 was applied using the following composition as a conductive layer paint.
The conductive support of the present invention was produced in exactly the same manner as in Example 1, except that g/rrr was used.

(Left below) Example day The coating amount was 6g using the following composition as the paint for the conductive layer.
The conductive support of the present invention was produced in exactly the same manner as in Example 1, except that /rrr was used.

Comparative Example 1 A comparative conductive support was produced in exactly the same manner as in Example 8, except that a coating material with the following composition was used as a coating material for the conductive layer.

Comparative Example 3 Completely the same as Example 1 except that an acrylic polymer consisting of 100% polymerizable vinyl monomer represented by the following general formula (1) was used instead of the acrylic copolymer in the conductive layer paint. A comparative conductive support was prepared.

Comparative Example 2 A comparative conductive support was produced in exactly the same manner as in Example 1, except that a coating material with the following composition was used as a coating material for the conductive layer.

On the conductive layer of the conductive support prepared in Examples 1 to 8 and Comparative Examples 1 to 3 above, a recording layer coating material having the following composition was applied and dried to form a recording layer with a coating amount of 5 g/rrf. An electrostatic recording medium of the present invention or for comparison was produced.

Image evaluation and water resistance tests were conducted on the electrostatic recording material produced above in the following manner.

(1) Image evaluation: Using an electrostatic color plotter (manufactured by Versatic Co., Ltd., CE3436), 30°C 30%R
Images were formed on an electrostatic recording medium under the environmental conditions of 120°C, 60%RH, and 130°C, 80%RH, and image density (black areas were measured using a Macbeth reflection densitometer RD-514) and image quality were evaluated. did. The image quality was evaluated as ◯ if there was no image quality defect such as image roughness or skipping, and × if at least one of the above image defects was observed to a practical extent.

(2) Water resistance test: After immersing the electrostatic recording material on which the image was formed in the above image evaluation in water for 24 hours, those with no swelling or peeling of the recording layer are marked as ○, and those with swelling or peeling. Those in which this was recognized were marked as ×.

The results of the image evaluation and water resistance test are shown in Table 1, and it was confirmed that the electrostatic recording material of the present invention had good recording properties and excellent water resistance.

Table 1 In addition, a photosensitive layer coating having the following composition was applied and dried on the conductive layer of the conductive support prepared in Examples 1 to 6 and Comparative Example 3 to form a photosensitive layer with a thickness of 15 μm. A lithographic printing original plate using the conductive support of the present invention and a comparative lithographic printing original plate were prepared.

It was confirmed that the lithographic printing original plate using the transparent support had good electrophotographic properties and printability.

When the lithographic printing original plate prepared above was immersed in water for 24 hours to evaluate its water resistance, the comparative lithographic printing original plate showed swelling and peeling of the photosensitive layer, whereas the conductive printing plate of the present invention showed swelling and peeling of the photosensitive layer. The lithographic printing original plate using the conductive support was confirmed to have excellent water resistance without any problems.Furthermore, the lithographic printing original plate using the conductive support of the present invention was plate-made and processed in the following manner. When etching and continuous printing tests of 5,000 sheets were performed, prints with good images were obtained.
Effect of the invention] The conductive support of the present invention and the electrostatic recording material using the same are as follows:
By specifying the structure of the conductive layer as described above, it has low humidity dependence under a wide range of environmental conditions, has good recording characteristics, and has excellent water resistance, so it can be used outdoors and over a wide range of conditions. It has the excellent effect of being adaptable to various uses.

Patent applicant: Tomogawa Paper Mills Co., Ltd.

Claims (1)

[Claims] (1) In a conductive support provided with a conductive layer on at least one side of the support, the conductive layer comprises a polymerizable vinyl monomer represented by the following general formula (I) and at least one other polymerizable vinyl monomer. 1. A conductive support comprising an acrylic copolymer and a conductive whisker. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, R_1 is H or CH_3, R_2 is an alkylene group, R_3, R_4 and R_5 are an alkyl group having 1 to 4 carbon atoms or a benzyl group. , X is Cl, Br, CH_3SO_
4, represents C_2H_5SO_4. )(2) In an electrostatic recording material formed by sequentially laminating a conductive layer and a recording layer on at least one side of a support, the conductive layer has the general formula (I
1.) An electrostatic recording material comprising an acrylic copolymer of a polymerizable vinyl monomer represented by () and at least one other polymerizable vinyl monomer, and a conductive whisker.