JPH087451B2 - Film suitable for electrophotographic copying - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a film suitable for copying used in an electrostatic copying machine.

(Prior Art and Problems Thereof) Electrostatic copying machines are widely used, and plain paper has been generally used as the copying paper.

However, since plain paper has high electric insulation and is easily charged, various troubles due to charging occur. For example, double feeding (two sheets feeding) that occurs when feeding paper
In addition, sorting troubles and the like occur due to static electricity remaining after toner transfer that occurs when sorting copy paper with a sorter.

Conventionally, in order to solve the above-mentioned problems caused by electrification, plain paper is subjected to antistatic treatment. However, in the case of such a charged paper, there is a problem in the electronic copying process that the electrification voltage is insufficient and the toner of a sufficient density cannot be applied on the paper, which is not yet satisfactory.

(Problems of the Invention) An object of the present invention is to solve the above problems found in conventional electronic copying paper.

(Means for Solving the Problems) The present inventors have completed the present invention as a result of intensive studies to solve the above problems.

That is, according to the present invention, a synthetic resin film is used as a base film, and a chemical mat layer having fine irregularities due to a surface roughening agent is formed on one or both surfaces of the base film, and the chemical mat layer is formed on the surface of the chemical mat layer. An antistatic layer having surface irregularities corresponding to the fine irregularities on the surface of the mat layer is formed, and the following (A) to
A film suitable for electrophotographic copying, characterized by using a composition comprising (E).

(A) Acrylic emulsion (B) The following formula (In the formula, R ¹ and R ² are respectively the same or different higher alkyl groups, X ¹ and X ² are hydrogen atoms or a group represented by —SO ₃ M (M: metal atom or ammonium ion),
X ¹ and X ² are not hydrogen atoms at the same time. ] The dialkyl sulfonic-acid type surfactant shown by these (C) melamine resin (D) crosslinking catalyst (E) inorganic filler (rough surface forming agent) is provided.

The electrophotographic copying film of the present invention has a structure in which a specific chemical matte layer is provided on one side or both sides of a synthetic resin film, and an antistatic layer is further provided thereon.
In this case, if necessary, an anchor layer made of a polymer film can be interposed between the chemical mat layer and the base film.

A general polymer film is used as the base film. Examples of such materials include polyester, polyamide (nylon), polypropylene, polyester, cellulose acetate, polyvinyl chloride, polystyrene, polymethacrylate and copolymers thereof, and polycarbonate. The thickness is not particularly limited, but is generally 25 μm to 250 μm.

The chemical mat layer is formed from a composition containing the following components (A) to (E).

(A) Acrylic emulsion (B) The following formula (In the formula, R ¹ and R ² are respectively the same or different higher alkyl groups, X ¹ and X ² are hydrogen atoms or a group represented by —SO ₃ M (M: metal atom or ammonium ion),
X ¹ and X ² are not hydrogen atoms at the same time. ] The dialkyl sulfonic acid type surfactant shown by (C) Melamine resin (D) Crosslinking catalyst (E) Inorganic filler (rough surface forming agent) Hereinafter, the chemical mat layer components (A) to (E) will be described in detail. To do.

Component (A) (Acrylic Emulsion) Examples of the main component constituting this emulsion include acrylic homopolymers, vinyl acetate-acrylic copolymers, styrene-acrylic copolymers and the like. The ionicity may be either nonionic or anionic. Further, it may be either a self-crosslinking type or a reaction type. The concentration is not particularly limited and can be selected from a wide range. Regarding the liquid property, weakly acidic to weakly alkaline ones are preferable.

Component (B) (dialkyl sulfonic acid type surfactant) In the formula (I), the higher alkyl group represented by R ¹ and R ² is a C _{5 to} C ₁₅ , preferably a C _{7 to} C ₁₂ alkyl group. is there.

X ¹ and X ² are groups represented by —SO ₃ M (M: Na, K, Li, NH ₄ etc.) or a hydrogen atom, and X ¹ and X ² are not hydrogen atoms at the same time, in other words, , X ¹ and X ² are at least -SO
It is required to be a group represented by ₃ M.

A preferred specific example is the following sodium dioctyl monosulphosuccinate.

This component (B) serves to prevent the composition from being repelled when it is applied to a synthetic resin film and to prevent pinholes from appearing in the coating film. It has the effect of lowering the surface tension of the coating liquid.

Component (C) (melamine resin) Various conventionally known compounds can be used. In addition to the melamine alone resin, a melamine-urea co-condensation resin can also be used.

Component (D) (Crosslinking catalyst) For example, ammonium chloride and ammonium oxalate are suitable. It is considered that these act as a crosslinking catalyst for the melamine resin. Some of them also have a cross-linking effect on acrylic emulsions. For example, ammonium chloride is decomposed into ammonia and hydrogen chloride by heating, hydrogen chloride acts as a crosslinking catalyst, and then the decomposed product is discharged out of the system in the drying step and does not finally remain in the coating film. .

Ingredient (E) (inorganic filler) For example, natural silica, synthetic silica, titanium oxide, silicon oxide, diatomaceous earth, magnesium carbonate, calcium carbonate, aluminum hydroxide, alumina, talc, clay, etc. Is.

The preferred particle size is 0.1 to 10 μm, particularly preferably 0.5 to
5 μm. If the average particle size is too large, the writing feel becomes poor. Further, a good dispersed state cannot be obtained at the time of preparation of the composition, and coating unevenness occurs at the time of coating. On the other hand, on the other hand, if it is too small, the glue on the pencil will deteriorate, and a problem will occur in writing.

In the present invention, a desired effect can be achieved by selecting and using a specific inorganic filler as the inorganic filler. Specifically, three kinds of calcium carbonate, silicon dioxide and titanium oxide may be used in combination. The combined ratio of these three types is preferably about 6: 14: 1 (weight ratio).

 The compounding ratios of specific examples of the composition are as follows.

Component (A) 100 parts by weight (solid content) Component (B) 0.5-10, preferably 1-5 parts Component (C) 40-160, preferably 80-120 parts Component (D) 0.1-10, 1 to 5 parts by weight Component (E) 10 to 200 parts by weight, preferably 80 to 140 parts by weight In the present invention, this chemical mat layer has a relationship with an antistatic layer formed as an overcoat layer on the surface thereof, Center line surface roughness 0.5-1.3 μm, preferably 0.6
It is preferable to specify the thickness to be 1.0 μm. The thickness is preferably 2 to 15 μm, more preferably 3 to 7 μm.

In the present invention, the antistatic layer formed on the chemical mat layer has on its surface fine irregularities corresponding to the fine irregularities of the chemical mat layer on the lower surface thereof. Such a fine uneven surface is formed by forming the antistatic layer as a thin film. The thickness of this antistatic layer is generally from 0.01 to
0.2 μm, preferably 0.02 to 0.1 μm, and its center line surface roughness is 0.4 to 1.2 μm, preferably 0.6 to 1.0 μm. The antistatic layer is formed by applying a coating solution prepared by dissolving or dispersing the antistatic material as described above in an aqueous medium or an organic solvent onto the chemical mat layer by a conventional coating method and drying.

In the present invention, the antistatic layer formed on the chemical mat layer has a surface resistivity value of 1 × 10 ⁸ of the obtained film.
It may be formed in the range of Ω to 1 × 10 ¹⁰ Ω. The surface specific resistance value can be adjusted by adjusting the concentration of the antistatic agent in the coating liquid or the thickness of the antistatic layer.

As the antistatic material for forming the antistatic layer,
For example, conductive metal oxides such as conductive stannic oxide, indium oxide, and zinc oxide, polyvinyl alcohol,
Polymers such as styrene-butadiene copolymer, vinyl chloride-vinyl acetate copolymer, polybutadiene, polyester, acrylic copolymer; inorganic salts such as lithium chloride; polymeric quaternary ammonium salt and high Examples thereof include polymer electrolytes such as molecular sulfonates.

In the electrophotographic copying film of the present invention, when a polymer film is provided as an anchor layer between the base film and the chemical mat layer, examples of the polymer include polyester, polyamide, polypropylene, polycarbonate, polyvinyl alcohol and the like. Although the thermoplastic resin (1) is generally used, a thermosetting resin, an ultraviolet curable resin or the like can also be used. A thermoplastic polyester resin (saturated polyester resin) is preferably used, and either a water-dispersed type or a solvent-soluble type may be used.

(Effect of the Invention) The film suitable for electrophotographic copying of the present invention has the above-mentioned constitution and is used as a copying paper in an electrostatic copying machine, and troubles caused by electrification as seen in the conventional copying paper. Does not occur. Further, in the electronic copying process, a sufficient charging voltage is exhibited, and the problem of insufficient toner density on the copy paper does not occur.

In addition, the film of the present invention has excellent writability similar to that of conventional plain paper because the surface of the film is formed on the surface of fine irregularities.

(Example) Next, the present invention will be described in more detail with reference to examples. The parts and% shown below are based on weight.

Examples and Comparative Examples The following components were mixed and uniformly dispersed to prepare a chemical mat liquid.

Synthetic silica (average particle size 4 μm) 5.0 parts Synthetic silica (average particle size 7 μm) 2.0 parts Calcium carbonate (average particle size 1 μm) 3.0 parts Titanium white 0.5 parts Surfactant solution (see Table-1) 6.8 parts Ammonia (concentration 5% aqueous solution) 1.4 parts Styrene / acrylic emulsion 9.7 parts Acrylic emulsion 7.5 parts Water-soluble melamine resin 10.1 parts Ammonium chloride (20% aqueous solution) 1.1 parts Water 24.5 parts The obtained chemical mat liquid is a polyethylene terephthalate film (thickness: 38 μm, 50 μm or 75 μm) on both surfaces so that the film thickness after drying is 7 to 8 μm, and after drying, a quaternary ammonium salt-based antistatic agent
1.2 parts, methyl cellosolve 2.5 parts, ethyl alcohol 10.0
Of the antistatic liquid consisting of 3 parts of water and 36.3 parts of water has a thickness of 0.
03-0.05μm (Film Nos. I-IV) and 5-10μm
A film for electrophotographic copying was obtained by coating and drying so that (Film No. V) was obtained.

Although the film Nos. I to IV had an antistatic layer having a surface fine unevenness corresponding to the fine unevenness on the surface of the chemical mat layer, the antistatic layer of film No. V had a shape of the fine unevenness of the chemical mat layer. However, the entire surface of the unevenness of the chemical matte layer was covered, and the surface itself had a smooth surface. The properties of these films are shown in the following table.

Next, each of the films obtained above was subjected to a copy test using a copying machine (RICOPY FT5840, manufactured by Ricoh Co., Ltd.), and its performance was evaluated as follows. The results are shown in Table-2.

(Image density) Compare the copy film obtained by copying with the original,
It was examined whether there was a decrease in density, and whether or not some or all of the toner was chipped.

(Double feed) The number of double feeds when 50 films were continuously copied was examined.

(Toner Adhesion) An adhesive tape was attached to the image side of the copy film obtained by copying, and when peeled off, the degree of the image transferred to the tape was examined.

Continuation of the front page (56) References JP-A-57-182757 (JP, A) JP-A-57-14849 (JP, A) Actually developed 58-88241 (JP, U)

Claims (1)

[Claims] 1. A synthetic resin film is used as a substrate film, and a chemical mat layer having fine irregularities on the surface is formed on one or both sides of the substrate film, and the chemical mat layer surface is formed on the surface of the chemical mat layer. Suitable for electrophotographic copying, characterized in that an antistatic layer having a surface fine unevenness corresponding to the fine unevenness is formed and a composition comprising the following (A) to (E) is used as the chemical mat layer forming component. Film. (A) Acrylic emulsion (B) The following formula (In the formula, R ¹ and R ² are respectively the same or different higher alkyl groups, X ¹ and X ² are hydrogen atoms or a group represented by —SO ₃ M (M: metal atom or ammonium ion),
X ¹ and X ² are not hydrogen atoms at the same time. ] A dialkylsulfonic acid-based surfactant represented by (C) Melamine resin (D) Cross-linking catalyst (E) Inorganic filler (rough surface forming agent)