JPS5829754B2 - Original drawing copy sheet for projection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an original projection copy sheet used for projecting a desired image onto a screen.

Projectors such as overhead projectors are used at lectures, presentations, briefings, etc. when it is desired to easily and accurately convey information by projecting printed materials, sketches, or drawings onto the projection screen at the venue. has been done.

Various proposals have been made for projection original drawing sheets used in overhead projectors, and some of them are already in use, but there are problems with image quality, storage stability, price,
Each has advantages and disadvantages in terms of ease of handling, manufacturing method, etc.

For example, a sheet of transparent film coated with thermoplastic resin in layers, or a sheet of thermoplastic resin molded into a film, is deformed by heating to form a fine uneven image and used as an original sheet for projection. Yes, but
With this sheet, the copied image is ugly and it is difficult to distinguish the copied content until it is projected, making it extremely inconvenient to handle, and it is also difficult to copy printed matter with halftones, such as photographic images.

Further, a donor sheet in which the composition in which a coloring agent is dispersed in a thermoplastic resin is coated on a substrate in layers, and a transparent film receiving sheet are overlapped, and the colored layer on the donor sheet is transferred onto the receiving sheet by heating. There is a method of transferring the image to form a colored image and using it as an original projection sheet.

Although the copying sheet has a good shelf life, it has the drawback that the coloring agent absorbs infrared rays and the resolution of the image decreases in the commonly used thermal copying method.

Alternatively, a two-layer sheet consisting of a thermoplastic resin film containing at least one component of the heat-sensitive color-forming composition consisting of at least two components and a film containing the other component of the heat-sensitive color-forming composition is formed, and the sheet is melted by heating. There is a method of reacting a heat-sensitive coloring composition to form a colored image and using it as an original projection sheet, but during storage, the coloring composition in the unheated area may gradually react and become colored. Another drawback is that it tends to cause blurring in the copied image.

Further, in the latter two-step method, since the sheet has a two- or three-layer structure including the base, manufacturing of the sheet is troublesome and it is difficult to reduce the thickness of the sheet.

As a result of various studies aimed at solving the above-mentioned drawbacks of conventional copying sheets, the present invention has been developed by making the resin layer itself constituting the copying sheet function both as a sheet and as a heat-sensitive coloring agent. This invention was made based on the discovery that a copying sheet free from the above-mentioned defects can be obtained and that the combination of a vinyl chloride resin and an acid-sensitive leuco dye has an excellent coloring function.

That is, the present invention relates to an original image copying sheet for projection, which has a recording layer that is a transparent film of a composition comprising a vinyl chloride resin and an acid-sensitive leuco dye.

In addition to polyvinyl chloride, the vinyl chloride resin used in the present invention includes vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, and vinyl chloride-propylene copolymer. vinyl chloride-styrene copolymer, vinyl chloride-vinyl stearate copolymer, vinyl chloride-methyl acrylate copolymer, vinyl chloride-butyl acrylate copolymer, vinyl chloride-octyl acrylate copolymer, Copolymers of vinyl chloride and other monomers such as vinyl chloride-dibutyl maleate copolymer, vinyl chloride-lauryl vinyl ether copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, chlorinated polyethylene , chlorinated polypropylene, chlorinated vinyl polymers such as chlorinated polyvinyl chloride P, chlorinated rubber, polyvinylidene chloride, and copolymers of vinylidene chloride and other monomers such as vinylidene chloride-acrylonitrile copolymer, etc. say.

In the present invention, one or more resins may be selected from among these resins as necessary, and these resins and other resins that are compatible with the resins may be used in combination. good.

In addition, in the present invention, the molecular weight of the vinyl chloride resin is preferably as small as possible, or has a high degree of branching in terms of molecular structure, and should have a molecular weight that does not impair film forming properties for film formation. It is preferable to use

Further, the acid-sensitive leuco dye used in the present invention refers to a leuco dye of triphenylmethane, fluoran, phenothiazine, auramine, and spiropyran organic dyes that develops color by reacting with an acidic substance.

Specific examples of the acid-sensitive leuco dye include, for example:
malachite grin leucobase, malachite grin leucocarbinol, malachite grin leuconitrile, malachite cline leucosulfonyl, crystal violet leucocarbinol, victoria blue leucocarbinol 1 aniline blue leucocarbinol, methyl violet leucocarbinol, rose rose aniline leucocarbinol Leuco forms of triphenylmethane dyes such as, phthalide compounds of triphenylmethane dyes such as malachite green lactone, crystal violet lactone, and methyl violet lactone, fluoran dyes such as rhodamine B lactone, rhodamine B lactam, and basic violet 10 lactone. Examples include leuco forms of phenothiazine dyes such as leuco methylene blue and benzoyl leucomethylene blue.

In the present invention, malachite kerine leuconitrile, rhodamine B lactone, and aniline blue leucocarbinol are particularly preferably used.

In the present invention, one or more of these acid-sensitive □ico dyes are selected and used depending on the desired color tone.

The amount used is not particularly limited and may be determined as appropriate depending on the density of the image produced during recording, but the amount is preferably 0.1 to 100 parts by weight per 100 parts by weight of the vinyl chloride resin. used.

As mentioned above, in the present invention, a composition consisting of a vinyl chloride resin and an acid-sensitive leuco dye is used, but the leuco dye in the composition inadvertently develops color at room temperature, that is, when unused. In order to eliminate the risk of this occurring and to improve the shelf life of the sheet, the composition may contain an electron donating substance that does not react with acids and develop color.

Electron-donating substances that do not develop color by reacting with the above acids include:
For example, quaternary ammonium salts such as alkyltrimethylammonium chloride, amines such as doderamine, didodecylamine, and triethanol, pyridinium salts such as alkylpyridinium chloride, heterocyclic compounds such as alkyloxazolines, and aromatic condensed rings such as pyrene. Hydrocarbons, alcohols such as hexanediol, etc. are used, but these electron-donating substances preferably have a boiling point of 150° C. or higher.

The electron-donating substance is preferably used in an amount of 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin.

Therefore, in the present invention, the composition is formed into a film to serve as a recording layer, but the film may have a continuous thickness and strength and may be used as a copying sheet by itself, or , the film may be provided on a suitable substrate.

Note that the above-mentioned film and substrate are required to be transparent in view of their use as a projection copying sheet in the present invention.

The transparent substrate is a transparent film that supports the recording layer obtained by coating and drying the above-mentioned composition, and does not substantially change at the temperature heated in a thermal copying machine. A film is used, for example a polyester film.

Film, polypropylene film, nylon film, cellophane film, etc. are preferably used.

Next, in order to form the composition into a film or provide it in a layer on a transparent substrate, for example, the composition is uniformly dissolved in the presence of a vinyl chloride resin solvent and then cast. Alternatively, a method may be adopted in which the composition is coated on a transparent substrate, cast, and dried to remove the solvent.

The projection copying sheet of the present invention is a sheet having the above-mentioned structure and has heat-sensitive coloring properties, and can be fed into a commonly used device such as a thermal copying machine to make copies. will be carried out.

The heat supplied from the copying machine causes the vinyl chloride resin that makes up the composition to react with the terminal double bonds present in its molecules, causing dehydrochlorination and the generation of radicals from thermally unstable areas such as branch points. occurs, and the acids resulting from these immediately react with the acid-sensitive leuco dye, producing a color tone unique to leuco dyes.

In other words, only the portion of the sheet that receives heat from the copying machine through the original image changes color and becomes visible, allowing it to function as a projection sheet.

As mentioned above, in the projection copying sheet of the present invention, the recording layer is made of a composition of a vinyl chloride resin and an acid-sensitive leuco dye, and when heated, the vinyl chloride resin becomes a coloring aid for the leuco dye. Work as.

Therefore, there is no need to separately include a dyeing aid such as an organic acid or a phenolic substance in the composition, and the vinyl chloride resin itself constituting the film can produce a coloring action.

Therefore, the types of substances constituting the composition can be reduced, each substance can be uniformly dispersed, and the layer of the composition can be made thinner, so that it is preferable as an original projection copying sheet.

In addition, in the present invention, there is no need to use other substances as a coloring aid, and the vinyl chloride resin acts as a coloring aid only when heated, so the sheet is not subject to impact or pressure. Even if there is a leuco dye, the leuco dye does not cause a coloring reaction, and there is no disadvantage that coloring or bleeding occurs due to reaction during storage or manufacturing.

In this manner, the present invention can provide a transparent copy sheet for projection originals that can be easily copied using a general thermal copying method, has good resolution, and has excellent storage stability.

Next, examples of the present invention will be described.

In addition, in each implementation column, parts simply mean parts by weight.

Example row 1 Polyvinyl chloride (degree of polymerization 800) 100 parts malachite green leuconitrile/L/8 parts pyrene
3 parts tetrahydrofuran
A mixture of 1,000 parts of the above composition was mixed and dissolved in a homomixer for 10 minutes to prepare a transparent liquid mixture.

The blended solution was cast onto a glass plate using a wire bar so that the thickness after drying would be 50 μm, and then dried to volatilize the tetrahydrofuran to obtain a transparent single-layer copying sheet.

When the copy sheet was superimposed on the original drawn with an HB pencil and thermally copied using a thermal copying machine, a clear green image was obtained, and the copy sheet with this image was then projected using an overhead projector. As a result, a clear green image was obtained.

After continuing to project for an hour in this state, the sheet became slightly colored, but the sharpness of the image hardly changed.

Example 2 Polyvinyl chloride (degree of polymerization 700) 100 parts Rhodamine B lactam 10 parts triethanolane 0.5 part tetrahydroalan
1000 parts of the above formulation was prepared in the same manner as in Example 1 to obtain a transparent single-layer copying sheet having a thickness of 50 microns.

When the copy sheet was overlapped with a copy made by a dry transfer type electrophotographic copying machine and heated and copied by a thermal copying machine,
A clear red image was obtained.

When the copy sheet with this image was projected onto a white screen using an overhead projector, a clear dark red image was obtained.

Further, the sheet did not become discolored even after projection was continued for another three hours in the same state.

Example 3 Vinyl chloride + vinyl acetate copolymer 100 parts Aniline blue leucocarbinol 13 parts Polyethylene oxide alkyl triamine (manufactured by Kako Atlas Co., Ltd., trade name Elec) 0.5 parts Rostripper-EA) Tetrahydrofuran 1000 parts A blend consisting of the above composition The ingredients were mixed and dissolved for 10 minutes using a homomixer to prepare a transparent mixed solution.

The mixed solution was applied onto a polyethylene terephthalate sheet with a thickness of 50 μm so that the thickness of the coating layer after drying was 10 μm.
It was coated using a roll coater and dried to obtain a transparent copy sheet.

When the copy sheet was placed with the coated side facing down on an original image printed with black ink on art paper and Rikishima copying was performed using a thermal copying machine, a clear indigo blue image was obtained.

When the copy sheet on which this image was obtained was projected onto a screen using an overhead projector, a clear dark blue image was obtained, and the reproducibility of the halftone portion was also good.

Furthermore, the resolution was 3.2 lines/resolution, and the storage stability was also good.

Claims (1)

[Scope of Claims] 1. An original image copying sheet for projection, the recording layer being a transparent film of a composition comprising a vinyl chloride resin and an acid-sensitive leuco dye. 2. An original image copying sheet for projection according to claim 1, wherein the composition contains an electron-donating substance that does not develop color upon reaction with an acid. 3. An original image copying sheet for projection according to claim 1 or 2, wherein a transparent film of the composition is provided on a transparent substrate.