JP3440341B2 - Image receiving sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image receiving sheet, and more particularly to an OHP sheet for an electrophotographic copying machine.

[0002]

2. Description of the Related Art OHP is an information transmission method widely used at lectures, schools, and other information sessions. As a method of forming an image on this OHP sheet, there have been adopted methods of handwriting with oil-based ink or the like, printing, and an electrophotographic copying machine. In order to reliably record and hold record information such as lines, characters, and images on the OHP sheet by using these means, what is generally used as the OHP sheet has a structure in which a receiving layer is formed on a transparent base material. Has become.
When forming a color image on an OHP sheet for an electrophotographic copying machine, the transparency and smoothness of the toner layer after fixing must be high. In order to meet such requirements, the transparency and low melt viscosity of the binder for the color toner are required. From the above viewpoints, JP-A-3-198063
JP-A-4-125567 proposes an image-receiving sheet coated with a substance having a melting point not lower than the fixing temperature of the toner at room temperature or higher and compatible with the binder resin of the color toner. JP-A-4-125567 discloses a softer image receiving sheet than the color toner. A transparent transfer medium formed with a toner image-holding layer containing a thermoplastic resin at the point is proposed. The softening point or melt viscosity of the receiving layer resin is defined, and the toner is taken into the receiving layer and printed matter with less unevenness. By solving the above problem, the above problem is solved. Also,
Japanese Unexamined Patent Publication No. 2-47667 proposes an OHP sheet provided with a porous surface layer made of a polyester resin.

[0003]

In color printing, since three or four color toners are usually stacked and heat-fixed, the toner overlaps more than in a single color, and the surface of the printed matter is likely to be uneven after heat-fixing. . In this case, the incident light is scattered by the uneven portion during projection, and sufficient color reproducibility of the projected image cannot be obtained especially in the highlight portion. The OHP projection image becomes turbid (grayed). It is an object of the present invention to provide an image-receiving sheet capable of forming a high-quality full-color image by using a polyester containing a specific diol component as the receiving layer resin.

[0004]

In order to achieve the above object, the present invention provides an image-receiving sheet having a receiving layer provided on a transparent substrate, the receiving layer comprising a polyester resin as a main component, and the polyester resin. Is a modified bisphene having the following chemical formula
The image-receiving sheet is composed of a diol component represented by Nool A and an acid component.

[Chemical 3]

[0005]

By using a polyester resin having a modified bisphenol A as a diol component in the receiving layer, the compatibility with the toner binder resin is good and the adhesion and color development with the toner are improved both thermally and chemically. To do.

[0006]

A preferred embodiment of the image receiving sheet of the present invention will be described with reference to the drawings. FIG. 1 shows a basic structure of an image receiving sheet of the present invention, in which a receiving layer 2 is formed on a transparent substrate 1. FIG. 2 is an application example of the image-receiving sheet of the present invention, in which the receiving layer 2 is provided on the transparent substrate 1, the detection mark 5 is provided thereon, and the antistatic layer 3 is provided on the back surface of the transparent substrate 1. . Figure 3
Is also an application example of the image-receiving sheet of the present invention, in which the receiving layer 2 is formed on the transparent substrate 1, the antistatic layers 3 and 4 are formed on the receiving layer and the back surface of the transparent substrate 1, and the antistatic layer is formed on the back surface. Detection mark 5
Is formed.

The transparent substrate used in the OHP image-receiving sheet of the present invention includes polyolefin films such as polyester films, polyethylene films and polypropylene films, polycarbonate films, triacetate films, polyether sulfone (PES) films, polyether ethers. Examples include ketone (PEEK) film, vinyl chloride film, various acrylic films such as methylmethacrylate, or cellophane film. Among them, polyester film, rigid vinyl chloride, polypropylene film, or triacetate film is preferable. As the base material, a base material whose adhesion to the receiving layer is improved by the undercoating treatment may be used.
The thickness of the base sheet used for this purpose is appropriately determined depending on the recording means, the required strength, etc., but the thickness is usually 10 to 300 μm, preferably 70 to 130 μm.

The resin for forming the receiving layer provided on the transparent substrate is mainly composed of a polyester resin, which is composed of a diol component represented by modified bisphenol A represented by the following chemical formula and an acid component. Is.

[Chemical 4] As the diol component, ethylene glycol or propylene glycol modified bisphenol A represented by the above chemical formula is used. As the acid component, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid, maleic acid, succinic acid, adipic acid, citraconic acid, itaconic acid, sebacic acid, malonic acid, hexacarboxylic acid and the like can be used without particular limitation. In addition, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, vinyl chloride / vinyl acetate copolymer, polyacrylic acid ester, polyethylene terephthalate, polybutylene terephthalate, polystyrene resin, polyamide resin It is also possible to use a commonly used receptive layer forming resin such as a copolymer of an olefin such as ethylene or propylene with another vinyl monomer, a cellulosic resin such as an ionomer, ethyl cellulose or cellulose acetate, or a polycarbonate resin. The diol component is propylene glycol of the following chemical formula
A modified bisphenol A and a polyester resin containing fumaric acid as an acid component are the most preferable and have good compatibility with the toner fixing resin, and a good printed image can be obtained.

[Chemical 5] The receiving layer is formed by further coating a composition prepared by dissolving or dispersing in a suitable solvent by adding various auxiliaries to the above-mentioned resin, if necessary, and drying the composition on the substrate by a known method. . The thickness of the receiving layer is usually 1 to 20 μm.

The organic and inorganic fine particles added to the receiving layer preferably have an average particle size of 0.1 to 10 μm. For example, for the purpose of imparting lubricity, tetrafluoroethylene polymer or ethylene-tetrafluoroethylene polymer is preferred. Fluoropolymers such as, stearates such as zinc stearate, organic polymers such as polyethylene, polystyrene, nylon, benzoguanamine, silica, colloidal silica, inorganic fine particles such as alumina, wax, silicone oil, surfactant, vegetable oil, Animal oil, mineral oil and the like are used, and among them, the fluorinated polymer is most suitable because the polymer itself has excellent surface lubricity. In addition, for the purpose of preventing double feeding due to blocking that occurs when the image receiving sheet is supplied to the printer, polyolefin fine particles such as polyethylene, polystyrene fine particles, polyacrylic fine particles, organic polymer fine particles such as ethylene acrylic acid copolymer fine particles, and silica, Inorganic particles such as colloidal silica, kaolin, clay, talc, silica, aluminum hydroxide, titanium dioxide, calcium carbonate, aluminum sulfate, zinc oxide, etc., and fine particles of glass beads, etc. to the extent that the transparency of the receiving layer is not impaired It is possible to add in. It should be noted that these fine particles are preferably mixed in a proportion of 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin for forming the receiving layer. Receptor layer forming resin If the content of fine particles is higher than that of the resin, the transparency decreases, and when transparency is required as an image-receiving sheet, it is preferable to keep the haze at 10 or less. It is preferable to mix the resin in an amount of 0.1 to 3 parts by weight with respect to 100 parts by weight of the resin.

Examples of the antistatic agent contained in the surface of the receiving layer or in the receiving layer include cation type antistatic agents such as quaternary ammonium salts and polyamine derivatives, anion type antistatic agents such as alkyl phosphates and fatty acid esters. Nonionic antistatic agents and the like. Further, as the resin type antistatic agent, those obtained by grafting the antistatic agent on a resin such as acrylic resin are also used. These antistatic agents are preferably mixed in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin for forming the receiving layer. When the content of the antistatic agent is higher than that of the resin for forming the receiving layer, the original performance of the receiving layer is deteriorated, and when the content of the antistatic agent is lower than this, a good antistatic effect cannot be obtained. When the antistatic layer is provided on the back surface of the transparent substrate, the antistatic agent is diluted with a solvent such as alcohol and applied to the back surface of the transparent substrate by gravure printing, spray coating, etc. Form an antistatic layer of ˜3 μm.

The detection mark of the present invention has a thickness of 0 on the receiving layer or on the back surface by printing a desired pattern by a usual printing method such as gravure printing or silk screen printing with a resin varnish obtained by adding a solvent to a resin component. 0.5-10 μ
m detection marks are formed. When the detection mark is formed on the back surface, it can be formed between the base material sheet and the antistatic layer or on the antistatic layer. Further, the shape, number, etc. of the detection marks are not particularly limited and can be arbitrarily provided. The solvent used for the resin varnish is a solvent that has a high solubility in the resin and a poor solvent that has a low solubility in the resin, and is used in the process of drying the printed film. The balance of the dissolved solvent is lost, and some of the resin becomes insoluble, cloudy, precipitated, and locally gelled.By further evaporating the poor solvent as the drying process progresses, it becomes porous. Layer is obtained, and an opaque layer is formed to function as a detection mark. In order to form a good porous layer, the resin varnish is formed by using 10 to 70 parts by weight of the poor solvent with respect to 100 parts by weight of the resin component.

The resin component is preferably an acrylic resin, a polyester resin, or a vinyl chloride / vinyl acetate copolymer. These glass transition points are 30 ° C. or higher, 1
It is preferably 50 ° C. or lower, particularly in the range of 50 to 130 ° C. When the melting point exceeds 150 ° C., when the organic porous layer is melted, the substrate may be deformed by heat, which is not preferable. It is not preferable to use a resin having a temperature of 30 ° C. or lower because of the problem of storage stability. As poor solvents for the above resin components, there are aliphatic hydrocarbons, aromatic hydrocarbons, hydrocarbon solvents such as terpene hydrocarbons, halogenated hydrocarbons, and alcohols. Further, for the resin component, as a solvent, for solvent-soluble resin, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate, butyl acetate, esters such as ethylene glycol monomethyl ether acetate, or resin Depending on the case, aromatic hydrocarbons and alcohols are applicable. When a water-soluble resin is used, the poor solvent for the solvent-soluble resin becomes a hydrophilic solvent, and the hydrophilic solvent is appropriately used depending on the compatibility with the resin so that the hydrophilic solvent becomes a poor solvent. Further, in the present invention which uses a good solvent and a poor solvent together, in order to keep the dispersion state of the varnish stable, the boiling points of the poor solvents having mutual solubility are higher than the boiling point of the good solvent, and those having a slow evaporation are used. To do. As a result, in the process of drying the varnish, the resin in the varnish is made insoluble, and the coating film is whitened and made porous. The pore diameter of the porous film thus formed is 0.0
It is preferably 5 μm to 2 μm. In order to form the pore diameter of the porous membrane within this range, the drying temperature, the amount of drying air, the drying time, and the mixing ratio of the poor solvent and the hydrophilic solvent are optimized. If the pore size is as small as 0.05 μm, a good whitening state cannot be obtained, and the function as a detection mark is insufficient. If it is larger than 2 μm, the film strength becomes weak, which is not preferable. The formed detection mark is transparent because the resin component is melted and resolidified by the heat (100 to 150 ° C.) of the heat roll that fixes the toner. The detection marks formed by either method have a transmittance in the wavelength region of 400 to 1000 nm of 50% or less before printing and 75% or more after printing, or a reflectance of 20% or more before printing and after printing. 10%
It is as follows.

As another method of forming the detection mark, it is possible to form the detection mark by using organic fine particles which are melted by heating and whose particle size is broken. Such organic fine particles maintain the particle shape at room temperature and have a melting point of 150 ° C. or less,
It is preferably in the range of 30 to 130 ° C. Melting point 150
When the temperature is higher than 0 ° C., when the organic fine particles are melted, the substrate may be thermally deformed, which is not preferable. 30 ° C
The use of the following is not preferable because of the problem of storability. Specific organic fine particles include various waxes such as carnauba, microcrystalline, paraffin wax, montan wax, rice wax and polyethylene wax, and resins such as ethylene-vinyl acetate copolymer, low density polyethylene, ionomer and thermoplastic elastomer. Can be mentioned. The latter resin is generally used as a coating liquid for an aqueous dispersion solution. The average particle size of such organic fine particles is 0.1 μm or more, preferably 0.3 to 10 μm.
What is used. If this value is less than 0.1 μm, the particles become too small, and transparency already appears at the time of coating, which does not function as a detection mark. Such organic fine particles are usually present in the detection mark in a state of being bound to the binder resin. As the binder resin used,
There is no particular limitation as long as the particles can be fixed without destroying the particle size of the organic particles. The mixing ratio of the binder resin and the organic fine particles is 100 by weight.
On the other hand, it is preferable to use the binder resins 1 to 50. If the amount of binder resin becomes too large, it will not be possible to naturally destroy the particle size of the organic fine particles by only heating.
The detection mark cannot be erased reliably. Further, if the binder resin is too small, the inconvenience that the organic fine particles are not firmly fixed occurs. The detection mark containing the above material is, for example, after being applied on a base material in an emulsion state using an emulsifier as needed,
It is formed by drying. The formed detection mark is transparent when the resin component is melted and resolidified by the heat (100 to 150 ° C.) of the heat roll that fixes the toner.

[0014]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the text, parts and% are based on weight unless otherwise specified. Example 1 First, 100 μm of polyethylene terephthalate (T-60, manufactured by Toray Industries, Inc.) was used as a base material sheet, and a receiving layer coating solution having the following composition was coated thereon with a bar coater to give a coating amount of 5.0 g / An image-receiving sheet 1 of the present invention was obtained by forming a receiving layer so that the image-receiving sheet 1 had a thickness of m ² . Receptor layer coating liquid 1 Polyester resin 30 parts (polymer of fumaric acid and propylene glycol modified bisphenol A) Tg: 60 ° C., softening point: 100 ° C. Methyl ethyl ketone: toluene = 1: 1 70 parts Silica fine particles (average particle size 5 μm) 0.15 copy

Example 2 An image receiving sheet 2 of the present invention was obtained in the same manner as in Example 1 except that the receiving layer coating liquid 2 was used in place of the receiving layer coating liquid 1. Receptor layer coating liquid 2 Polyester resin 30 parts (polymer of fumaric acid and propylene glycol modified bisphenol A) Tg: 60 ° C, softening point: 100 ° C Antistatic agent (TB-34 manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.) 2 parts Methyl ethyl ketone: toluene = 1: 1 70 parts

Example 3 Using the same image-receiving sheet as in Example 1 in which a receiving layer was formed on a substrate sheet, a coating solution for the antistatic layer having the following composition was dried on the receiving layer and the back surface of the substrate sheet. Application amount of 0.1
After forming the antistatic layer by coating so as to be g / m ² , the detection mark ink 1 having the following composition was applied to the antistatic layer on the back surface by a gravure printing machine at a coating amount of 2 to 3 g / m ²
The image-receiving sheet 3 of the present invention was obtained by printing so as to provide a detection mark. Coating liquid for antistatic layer Antistatic agent (TB-34 manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.) 1 part Isopropyl alcohol 500 parts Ink for detection mark 1 PVC resin (manufactured by Dencarac Denki Kagaku KK) 30 parts Acrylic resin (Dianal manufactured by Mitsubishi Rayon Co., Ltd.) 1 part Poor solvent (n-butanol) 25 parts Acetone 35 parts

Example 4 An image receiving sheet of Example 4 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid 1 was replaced with the receiving layer coating liquid 3 having the following composition. Receptor layer coating liquid 3 Polyester resin 30 parts (Polymer of succinic acid and diethylene glycol modified bisphenol A) Tg: 65 ° C., Softening point: 110 ° C. Methyl ethyl ketone: Toluene = 1: 1 70 parts

Example 5 An image-receiving sheet of Example 5 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid 1 was replaced with the receiving layer coating liquid 4 having the following composition. Receptor layer coating liquid 4 Polyester resin 30 parts (Polymer of terephthalic acid and triethylene glycol modified bisphenol A) Tg: 50 ° C., softening point: 70 ° C. Methyl ethyl ketone: toluene = 1: 1 70 parts

Example 6 An image-receiving sheet of Example 6 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid 1 was replaced with the receiving layer coating liquid 5 having the following composition. Receptor layer coating liquid 5 Polyester resin 30 parts (Polymer of adipic acid and dipropylene glycol modified bisphenol A) Tg: 70 ° C., softening point: 110 ° C. Methyl ethyl ketone: toluene = 1: 1 70 parts

Example 7 An image receiving sheet of Example 7 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid 1 was replaced with the receiving layer coating liquid 6 having the following composition. Receptor layer coating liquid 6 Polyester resin 30 parts (Polymer of terephthalic acid and tripropylene glycol modified bisphenol A) Tg: 55 ° C, softening point: 90 ° C Methyl ethyl ketone: toluene = 1: 1 70 parts

Comparative Example 1 An image-receiving sheet of Comparative Example 1 was obtained in the same manner as in Example 1 except that the receiving layer coating liquid 1 was replaced with the receiving layer coating liquid 7 having the following composition. Receptor layer coating liquid 7 Polyester resin 30 parts (succinic acid and ethylene glycol) Tg: 60 ° C., softening point: 100 ° C. Methyl ethyl ketone: toluene = 1: 1 70 parts

Evaluation Method Using CLC-200 manufactured by Canon, after color printing in accordance with Color Test Chart No. 11 of the Institute of Image Electronics, the image and graying (cloudiness of OHP projected image) were visually judged, and the surface electric resistance value was determined. Was measured in an environment of 20 ° C. and 60% to see the antistatic effect.

[0023]

[Table 1]

[0024]

As described above, the image-receiving sheet of the present invention is
When the receiving layer contains a polyester resin composed of a diol component represented by modified bisphenol A represented by the following chemical formula and an acid component as a main component, it has good compatibility with the toner binder resin, and the toner is thermally and chemically The adhesiveness with and color development are improved. This makes it possible to form a high-quality full-color image without causing image turbidity (graying) during OHP projection.

[Chemical 6]

[Brief description of drawings]

FIG. 1 is a basic sectional view of an image receiving sheet of the present invention.

FIG. 2 is a cross-sectional view showing an application example of the image receiving sheet of the present invention.

FIG. 3 is a cross-sectional view showing an application example of the image receiving sheet of the present invention.

[Explanation of symbols]

1. Transparent base material 2. Receptive layer 3, 4 · Antistatic layer 5. Detection mark

[Chemical 1]

[Chemical 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-232736 (JP, A) JP-A-5-6020 (JP, A) JP-A-58-98496 (JP, A) JP-A-5- 289390 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 7/00

Claims (7)

(57) [Claims] 1. An image-receiving sheet comprising a transparent substrate and a receiving layer provided on the transparent substrate, wherein the receiving layer comprises a polyester resin as a main component, and the polyester resin is a modified bisphenol represented by the following chemical formula.
An image-receiving sheet comprising a polymer obtained by polymerizing a diol component represented by Nool A and an acid component. [Chemical 1] 2. The receiving layer comprises a diol component represented by the following chemical formula:
The image-receiving sheet according to claim 1, which comprises a propylene glycol-modified bisphenol A and a polyester resin containing fumaric acid as an acid component as main components. [Chemical 2] 3. The receiving layer has an average particle size of 0.1 to 10 μm.
3. The image-receiving sheet according to claim 1, which contains m inorganic and / or organic fine particles. 4. The image-receiving sheet according to claim 1, further comprising an antistatic agent on or in the surface of the receiving layer. 5. The image receiving sheet according to claim 1, wherein an antistatic layer is provided on the back surface of the image receiving sheet provided with a receiving layer on a transparent base material. 6. The image receiving sheet according to claim 1, wherein the image receiving sheet has a receiving layer provided on a transparent substrate, and a detection mark is provided on one surface of the transparent substrate. 7. An image-receiving sheet having a receiving layer provided on a transparent substrate, wherein the detection mark provided on either surface of the transparent substrate is transparentized by heating.
Image receiving sheet described.