JPH07156568A - Image protective member and image protective method - Google Patents

Abstract

PURPOSE:To improve pollution resistance, weatherability and stability by a method wherein heat-transferable protective layer containing solvent-soluble fluorine-containing resin or its hardened matter and hot melt resin is separably provided on a tissue-like base. CONSTITUTION:Onto tissue-like base 3, weatherproof layer 2 and hot melt resin-containing bonding layer 1 are laminatingly formed from the base 3 side as independent layers so as to form heat transferable protective layer out of both the layers 1 and 2. The weatherproof layer 2 contains solvent-soluble fluorine-containing resin such as polytetrafluoroethylene or the like. Further, the weatherproof layer 2 may contain thermosetting or thermoplastic resin. The preferable thickness of the layer 2 is set to be about 2-50mum. The bonding layer 1 may well contain the same additive as that to the weatherproof layer 2 in addition to the hot melt resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention protects an image formed on a paper or film by an ink jet recording system, an electrophotographic recording system, a thermal transfer recording system, etc. to enhance its weather resistance and durability and to give a clean gloss. The present invention relates to an image protection member for improving artistic value and an image protection method using the same.

[0002]

2. Description of the Related Art Due to recent advances in color image forming technology, high-quality full-color recording can be performed on images of various materials by using a color hard copy recording apparatus such as an inkjet recording method, an electrophotographic recording method, and a thermal transfer recording method. It has become possible to do it on a support. However, these full-color images have drawbacks in fixability and stability, and in many cases, the images may be peeled off or soiled when they come into contact with chemicals or water or rub against other objects. For example, in a recorded image formed by an ink jet recording system or the like, a dye or pigment dissolved or dispersed in an aqueous medium is mainly used as a recording agent, so that the recorded image has water resistance and solvent resistance. The abrasion resistance is not always sufficient. In addition, many of the dyes and pigments used as recording agent components have poor light resistance when exposed to light for a long period of time such as exposure to the outdoors for a long time, and there is a problem that discoloration, fading or erasing of images easily occurs. . It is also vulnerable to contamination by various writing instruments, dust, cigarette smoke, and the like. This also applies to images obtained by the electrophotographic recording method and the thermal transfer recording method. Many recording materials such as papers used in these recording systems also have yellowing and low water resistance and stain resistance after long-term outdoor exposure.

Further, in the case of a porous recording material such as paper, since the surface of the recording material is not glossy, a silver salt color photograph or art paper can be used even for an image recorded clearly by an ink jet recording method. There is a drawback in that the sharpness of the image when viewed is insufficient as compared with the offset printed matter used. In order to eliminate such defects, a laminating method in which a thermoplastic film is thermally attached to the entire surface of the image has been conventionally performed, but a thermoplastic film having a small Young's modulus and easily wrinkled is laminated without wrinkles. Therefore, a thick film is often used, and the image support after laminating becomes thicker by the amount of the laminating film, so that the touch and impression are impaired, which is not always satisfactory. A method has also been proposed in which a plastic film is pressure-bonded after applying a liquid containing a fluorine-based resin to form a protective film (Japanese Patent Laid-Open No. 2-95883), but the operation is complicated.

As a remedy for this problem, there has been proposed a method in which a peelable protective layer is provided on a film, and this is thermally transferred onto an image to easily provide the protective layer on the image. JP-A-60-23096, JP-A-60-189486, JP-A-61-230973
Publications can be cited. By this method, the stability of the image could be easily improved, but the weather resistance and stain resistance were not always satisfactory.

[0005]

The image stability means not only the stability of the image itself to be protected after protection, but also the overall stability of the image including a protective layer provided on the image. It is a thing. It is possible to improve the stain resistance of the image compared to the state without the protective layer by providing the protective layer on the image formed on the recording material generally called plain paper by the conventional technology. Although it is considered that the conventional technology is insufficient in stain resistance of the protective layer itself, various writing instruments,
It does not have sufficient resistance to contamination by dust, exhaust gas, cigarette smoke, etc.

Regarding the weather resistance to long-term exposure to the outdoor environment, the conventional techniques have problems such as deterioration of the protective layer and loss of surface gloss, which impairs the appearance of the image. Therefore, it cannot be said that the weather resistance is sufficient. The present invention is intended to obtain an image having good stain resistance and weather resistance, that is, stability, including a protective layer, by using a specific material as a protective layer for the image, and obtaining such an image. An image protection member and a method for protecting an image using the same are provided.

[0007]

The above object of the present invention is to provide a heat transferable protective layer containing a solvent-soluble fluorine-containing resin or a resin which is cured with a curing agent and a hot-melt resin on a thin leaf substrate. An image protection member characterized by being provided in a peelable manner is used, and this is superimposed on the image to be protected formed on the recording material so that the thermal transferable protective layer faces the image, From the opposite side of the heat transferable protective layer of the protective member, heat and pressure are applied using a laminator, a thermal head, etc. to adhere the image to be protected to the heat transferable protective layer, and then the thin leaf-shaped substrate of the image protective member is attached. It is achieved by peeling and obtaining a surface-protected image.

The present invention will be described in detail below. Examples of the thin leaf substrate of the image protection member of the present invention include plastic film substrates such as polyester, polycarbonate, polyarylate, polyether sulfone, polyimide, polyamide, polyamideimide, polyfluoroethylene and polypropylene, and paper, cloth, metal. Examples of such materials include foils and the like, which are obtained by adhering these base materials to each other as necessary, and those whose surface is treated by applying a release treatment agent having various release properties such as silicon resin to the surface thereof. It can also be used. Further, if necessary, a heat resistant layer may be provided on one surface of the base material. The thickness of the substrate is usually 5 μm to 1 m
m, preferably 10 to 150 μm, and is selected in consideration of easiness of handling, heat transfer during heating, and the like.

Further, in the step of forming a heat transferable protective layer on the thin leaf-shaped substrate or in the step of thermally pasting the heat transferable protective layer on the image formed on the recording material,
Since appropriate heat resistance and heat stretchability are required, a film of a stretchable resin having low heat resistance such as polyethylene and soft vinyl chloride is not suitable. In addition, since an organic solvent is generally used in the step of forming the thermal transferable protective layer, a substrate having excellent solvent resistance in addition to heat resistance or a surface-treated substrate having excellent solvent resistance is used. It is desirable to do.

Generally, as the resin containing fluorine, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), fluorinated ethylene propylene (FEP), perfluoroalkyl vinyl ether tetrafluoroethylene (PFA), ethylene tetrafluoro Ethylene (ETFE), polyvinylidene fluoride (P
VdF), polyvinyl fluoride (PVF), and the like are known, but all of them are not suitable for the present invention because they are all highly crystalline polymers and do not dissolve in organic solvents at room temperature except PVdF.

The term "solvent-soluble" of the solvent-soluble fluorine-containing resin used in the present invention means that when a general-purpose organic solvent such as toluene, methyl ethyl ketone or ethyl acetate is used,
It has a solubility of 2% or more at 0 ° C. It is preferably used that exhibits a solubility of 10% or more, particularly 20% or more. Specific examples of such solvent-soluble fluorine-containing resin include tetrafluoroethylene, trifluoroethylene, difluoroethylene, monofluoroethylene, hexafluoropropylene, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, dichlorodifluoroethylene. Fluorine-containing olefins (fluoroolefins) and vinyl acetate,
Copolymers with vinyl esters such as butyric acid vinyl ester and stearic acid vinyl ester, copolymers with fluoroolefins and (meth) acrylic acid esters such as methyl acrylate, methyl methacrylate and butyl methacrylate, fluoroolefins Examples thereof include resins having a fluoroolefin such as a copolymer with vinyl ethers such as ethyl vinyl ether, chloroethyl vinyl ether and isobutyl vinyl ether as a skeleton constituent component.

When the above-mentioned copolymer with vinyl ester is saponified or when the above-mentioned fluoroolefins are copolymerized with other monomers, acrylic acid containing a hydroxyl group such as hydroxyethyl methacrylate and hydroxypropyl methacrylate. Those obtained by curing a solvent-soluble fluorine-containing resin having a hydroxyl group introduced by further copolymerizing an ester with a curing agent are also suitable for the present invention. The hydroxyl groups introduced into these resins can be easily crosslinked by using a crosslinking agent such as isocyanate as a curing agent.

The composition ratio of fluoroolefin to resin in these resins is preferably 1 mol% or more and 90 mol% or less, more preferably 2 mol% or more, 7
It is 0 mol% or less. As the solvent-soluble fluorine-containing resin, in addition to this, fluorine is added to the side chain of a (co) polymer of a fluorine-containing alcohol acrylate ester or a styrene (co) polymer containing a fluorine in the aromatic ring. There are resins included, which are also suitable for the purposes of the present invention. However, from the viewpoint of manifesting the effect, the resin having the above-mentioned fluoroolefin as a constituent component of the skeleton is preferable.

Specific examples of these solvent-soluble fluorine-containing resins (fluorine-containing soluble resins) include, for example, Lumiflon,
Fluoro Top (trade name, product of Asahi Glass Co., Ltd.), Zaflon (trade name, product of Toa Gosei Kagaku Kogyo Co., Ltd.), Cefraral Coat, Hilar (trade name, product of Central Glass Co., Ltd.), V Freon (trade name, Dainippon Paint Co., Ltd.) Company products), Aresflon (product name, Kansai Paint Co., Ltd. product), Duflon K (product name, Nippon Paint Co., Ltd. product), Floren (product name, Nippon Synthetic Rubber Co., Ltd. product) and other products are on the market, These can be used.

Isocyanates and melamines can be mentioned as a curing agent used in combination with a solvent-soluble resin containing a hydroxyl group and a fluorine, but an isocyanate capable of curing under milder conditions is used. Classes are preferred. As the isocyanates, there is little yellowing under long-term exposure, and polyisocyanates of aliphatic diisocyanates or alicyclic diisocyanates capable of forming a soft crosslinked product (polyfunctional, that is, isocyanate having a plurality of isocyanate groups) are preferable. Particularly, aliphatic hexamethylene diisocyanate-based polyisocyanate is preferable. Hexamethylene diisocyanate-based polyisocyanates are known to be modified in various ways, for example, buret modification, isocyanurate modification,
Urethane modification etc. Urethane modification includes trimethylolpropane modification and polyol modification. In particular, a polyol-modified polyisocyanate reacted with a polyol-modified hexamethylene diisocyanate-based polyisocyanate having a polyfunctional terminal isocyanate group is a resin in which various physical properties such as softness and extensibility are hardened by selecting a polyol. It is preferable because it can be given to

When isocyanates are used as the curing agent, the ratio of the amount used is 0.8 to 2.0 moles of hydroxyl groups in the solvent-soluble fluorine-containing resin per mole of NCO groups of the isocyanate compound of the curing agent. The amount is appropriate. It is more preferably 0.9 to 1.2 mol. A catalyst may be added to the reaction between the hydroxyl group and the isocyanate in order to accelerate the reaction rate. As the catalyst, a tin compound such as dibutyltin laurate or an amine compound such as triethylenediamine is used, and the addition amount thereof is about several tens to several hundreds ppm, and the addition amount of the resin when forming the thermal transferable protective layer is It is determined from the coatable time and the curing speed. Curing is normally completed at 60 to 150 ° C. in about 1 minute to several hours. Depending on the choice of catalyst, curing agent, etc., curing can be completed in a few days at room temperature.

The hot melt resin is used to improve the adhesiveness between the recording material and the image provided thereon with the heat transferable protective layer, and examples thereof include ethyl cellulose, vinyl acetate resin and the like. A thermoplastic resin such as a derivative, polyethylene, ethylene-vinyl acetate copolymer, acrylic resin, polystyrene and its copolymer, polyisobutylene, hydrocarbon resin, polypropylene, polyamide resin, polyester resin is used.

When the recording material is porous, it is preferable to select a resin having a low melt viscosity that melts and permeates during heat bonding. Further, in order to effectively utilize the heat at the time of heat bonding, it is advantageous that the glass transition temperature (Tg) is low,
It is preferably 70 ° C. or lower. The heat transferable protective layer can be provided on the thin leaf substrate as one layer consisting of a mixed phase of a solvent-soluble fluorine-containing resin and a hot-melt resin, but as shown in FIG. The weather-resistant layer (2) containing a and the adhesive layer (1) containing a hot-melt resin are formed as separate layers, and the weather-resistant layer (2) is adjacent to or adjacent to the thin leaf substrate (3). You can also do it.

When releasability is required between the substrate and the heat transferable protective layer, a releasable substrate is used, or a coating of a releasable material such as silicon is provided on the surface of the substrate. Good. Hereinafter, the structure of the image protection member of the present invention will be described with reference to FIG. The adhesive layer (1) is preferably provided on the outermost layer on the substrate (3) of the image protection member so that the adhesive layer (1) can be attached to the recording image surface by a process such as thermocompression bonding or heat fusion.
The weather resistant layer (2) is laminated on the outermost surface of the recording image surface, and for the purpose of functioning as a protective layer that imparts properties such as water resistance, light resistance, abrasion resistance, and solvent resistance to the recorded image, 3)
It is constructed in a form adjacent to or close to. If desired, an intermediate layer may be provided between the adhesive layer (1) and the weather resistant layer (2), or a protective layer may be further provided on the adhesive layer (1).

The weather resistant layer (2) may contain a thermosetting or thermoplastic resin in addition to a solvent-soluble fluorine-containing resin or a resin obtained by curing this with a curing agent. Further, for the purpose of improving the light resistance of the image, an ultraviolet absorber, an antioxidant, and an additive such as a light stabilizer may be appropriately selected and contained, and if necessary, a release agent, an inorganic or organic agent may be added. It may contain fine particles. The film thickness is 2-50μ
m, preferably 5 to 30 μm. If it is too thin, sufficient performance will not be expressed. If it is too thick, the transparency of the image will be insufficient, and the flexibility will be impaired.

The adhesive layer (1) may contain the same additives as the weather resistant layer (2), if necessary, in addition to the hot melt resin. The film thickness is usually 2 to 50 μm, preferably 5 to 30 μm. If it is too thin, sufficient adhesion cannot be obtained. As a method for providing the heat transferable protective layer on the substrate, a method is generally used in which the constituent materials are dissolved or dispersed in an organic solvent to obtain a coating solution, which is coated on the substrate and dried. Examples of the organic solvent include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, isopropyl alcohol, cyclohexanone, and the like, which may be used alone or in combination.

As a coating method, for example, bar coating,
Blade coat, die coat, reverse roll coat,
A coating method such as gravure roll coating can be used. A dry laminate coating method can also be used for the adhesive layer. When the heat-transferable protective layer is composed of a plurality of layers such as the weather resistant layer (2) and the adhesive layer (1), one layer is coated and dried using the above coating method, for example, It is possible to apply a method of applying a layer and then drying it, or applying a layer and then applying a next layer, and then passing the whole through a drying step.

The kind of the image protected by the present invention is not particularly limited, but it is particularly effective for protecting the image obtained by ink jet recording using a water-soluble recording liquid. Therefore, as the recording material of the image to be protected, one suitable for each recording method is used. As a means for providing a protective layer on a recording material using the image protective member of the present invention, a device generally called a laminator is used, and the heat transferable protective layer surface of the image protective member (adhesive layer surface if an adhesive layer is present). And the surface of the recording material on which the image is formed are overlapped, and then this is passed between the heated rolls of the laminator while applying pressure, and the adhesive layer is applied onto the recording material by the heat and pressure of the rolls. A method is generally used in which the film is adhered and then the thin leaf substrate of the image protection member is peeled off. In addition to this, for example, after the adhesive layer surface of the image protection member and the surface of the recording material on which the image is formed are overlapped and left still, heating and pressing are performed from the back surface of the image protection member using an iron or a flat-type heater. There is also a way to do. The heating temperature at this time is 50 ° C to 250 ° C.
C., preferably 80 to 200.degree. C.

[0024]

EXAMPLES Next, the present invention will be described more specifically by way of examples. The parts or% in the text are based on weight unless otherwise specified.

[0025]

Example 1 (a) Formation of Image Protecting Member Addition type silicone for release paper containing polysiloxane having vinyl group and polymethylhydrogensiloxane (trade name SRX211, Toray Dow Corning Silicone Co., Ltd.) Product) and platinum catalyst (Product name SRS21)
On a 25 μm thick polyethylene terephthalate (PET) film (trade name MRX-25, manufactured by DIAFOIL Hoechst Co., Ltd.) on which a release surface is formed by applying and diluting a diluted mixed liquid of 2CAT, Toray Dow Corning Silicone Co., Ltd.) In addition, a solvent-soluble resin containing a hydroxyl group and fluorine, which is a copolymer mainly composed of tetrafluoroethylene and vinyl ester (trade name: Fluorotop FT-1053, Asahi Glass Co., Ltd. product, solid content concentration 55% product, OH value 31 m).
gKOH / g resin) 100 parts and isocyanurate-modified hexamethylene diisocyanate-based curing agent (trade name Coronate HX, product of Nippon Polyurethane Company, solid content concentration 55)
% Product, NCO content 11.6%) and a resin solution of 20 parts is dried to a dry thickness of 20 μm, and a polyester resin (trade name: Byron # 200, Toyobo Co., Ltd.) as a hot-melt resin is further applied on the resin liquid. The product) was dissolved in a solvent and applied and dried to a dry thickness of 10 μm to obtain an image protective member having a heat transferable protective layer.

(B) Preparation of recording material 80 parts of water, 10 parts of polyvinyl alcohol (trade name: Gohsenol GL-05, manufactured by Nippon Gosei Co., Ltd.), 10 parts of powdered silica (trade name: Nipseal E200A, manufactured by Nippon Silica Company) Were mixed and dispersed with a homomixer to prepare a coating liquid.

A vinyl chloride vinyl chloride resin VYNC (trade name, manufactured by Union Carbide Co.) is applied as an anchor to a soft polyvinyl chloride sheet having a thickness of 100 μm so as to have a dry thickness of 3 μm, and then the above coating is performed using a bar coater. The liquid was applied so as to have a dry thickness of 20 μm to prepare a recording material.

(C) Printing / protection treatment An ink jet printer (trade name IO-735, manufactured by Sharp Corporation) is applied to the recording material prepared in (b) above.
Was printed using. The image protection member prepared in (a) above is overlaid on the recorded image of the above-mentioned printed matter, and a laminator (trade name: LPE850PRO, product of Fuji Plastic Co., Ltd.)
Was used for thermocompression bonding at a temperature of 140 ° C. and a speed of 2 m / min, and then the PET film was peeled off to obtain a protected recorded image.

(D) Contamination resistance evaluation test A line was drawn on the protected recorded image obtained in (c) above with a red and black magic ink at 1 cm intervals, and after 2 hours, a cloth sufficiently wetted with xylene. It was wiped 5 times at right angles to the line of the magic ink, and the degree of disappearance of the magic ink was judged.
The results were good as shown in Table 1 below.

(E) Weather resistance evaluation test The protected recorded image obtained in the above (c) was subjected to a weather resistance tester (trade name: Sunshine Super Long Life Weather Meter, Suga Test Instruments Co., Ltd.) in accordance with JIS B7753. Production) was used, and a test was performed for 2000 hours under the condition of water sprinkling for 20 minutes for 60 minutes. The gloss of the surface was measured with a gloss meter (trade name: Glossmeter SD, manufactured by Toyo Seiki Seisakusho Co., Ltd.) at 60 degrees.
The glossiness before the test was 60%, and the glossiness after the test was 53%, and the difference was small and judged to be good. The results are shown in Table 1 below.

[0031]

Example 2 (a) Formation of Image Protective Member Chlorotrifluoroethylene and vinyl were placed on a commercially available 60 μm release paper (trade name Honshu Alfan EAS, Honshu Paper Co., Ltd.), one side of which was treated with a silicone-based release agent. Solvent-soluble resin that is a copolymer mainly composed of ester and contains hydroxyl groups and fluorine (trade name: Sepral Coat 202B, manufactured by Central Glass Co., Ltd., solid content concentration 42% product, OH value 2
3.7 mg KOH / g resin) 80 parts, polyol-modified hexamethylene diisocyanate curing agent (trade name Coronate 2094, manufactured by Nippon Polyurethane Co., Ltd., solid content concentration 42% product, NCO content 6.9%) 20 parts, catalyst dibutyl Chin laurate (Product name: Neostan U-100, product of Nitto Kasei Co., Ltd., content: 50 ppm based on resin)
The resin liquid consisting of is coated and dried to a dry thickness of 15 μm, and then ethylene / vinyl acetate copolymer resin (trade name Polysol EVA
AD-3, Showa High Polymer Co., Ltd.) with a dry thickness of 5
It was coated and dried to a thickness of μm to obtain an image protection member having a heat transferable protection layer.

(B) Recorded Image A color image was obtained on PPC paper by using an electrophotographic color copying machine (trade name: Color Laser Copier 350, product of Canon Inc.). An image protection member was overlaid on the recorded image of the printed matter and thermocompression-bonded, and then the release paper was peeled off to obtain a protected recorded image. (C) Contamination resistance evaluation test The obtained recorded image was subjected to the same contamination resistance test as in Example 1, and the results are shown in Table 1 below. (D) Weather resistance evaluation test The obtained protected recorded image was subjected to the same weather resistance test as in Example 1. The glossiness before the test was 58% and the glossiness after the test was 50%, and the difference was small and judged to be good.
The results are shown in Table 1 below.

[0033]

Comparative Examples 1 and 2 The same procedure as in Example 1 was carried out except that the image protection member described below was used. The evaluation results are shown in Table 1 below. (A) Image Protection Member of Comparative Example 1 On the PET film provided with the release layer described in Example 1,
A resin solution mixed with 95 parts of polyester resin (trade name: Byron # 200, product of Toyobo Co., Ltd.) and 5 parts of an ultraviolet absorber (product name: Biosorb 130, product of Kyodo Chemical Co., Ltd.) is applied to a dry thickness of 10 μm. After drying, an image protection member was obtained. (B) Image protection member of Comparative Example 2 On the PET film provided with the release layer described in Example 1,
Acrylic resin (trade name BR-108, product of Mitsubishi Rayon Co., Ltd.) is applied and dried to a dry thickness of 20 μm, and polyester resin (trade name Byron # 2)
00, a product of Toyobo Co., Ltd.) was applied and dried to a dry thickness of 10 μm to obtain an image protection member.

[0034]

[Table 1] Example 1 Example 2 Comparative example 1 Comparative example 2 Contamination resistance ◎ ◎ × △ Weather resistance ◎ ◎ × × Evaluation method of stain resistance ◎: Magic ink disappears well △: Magic ink disappears to some extent ×: Magic ink does not disappear Weather resistance evaluation method ◎: Very little change in glossiness ×: Very large change in glossiness

[0035]

The surface-protected image obtained according to the present invention is excellent in stain resistance and weather resistance, that is, stability.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration of an image protection member of the present invention.

[Explanation of symbols]

 1 Adhesive Layer 2 Weatherproof Layer 3 Substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area G03G 15/20 // C08L 27/12 LGL

Claims (4)

[Claims] 1. An image protection member comprising a thin-leaf substrate and a heat transferable protective layer containing a solvent-soluble fluorine-containing resin and a hot-melt resin, which is releasable. 2. A heat transferable protective layer containing a hot-melt resin and a fluorine-containing resin obtained by curing a solvent-soluble resin containing fluorine and a hydroxyl group with a curing agent is provided on a thin leaf-shaped substrate in a peelable manner. An image protection member characterized by. 3. The image protection member according to claim 1, wherein the heat transferable protection layer has a weather resistant layer containing a fluorine-containing resin and an adhesive layer containing a hot melt resin,
An image protection member, characterized in that the weather resistant layer is provided adjacent to or in proximity to the thin leaf substrate. 4. An image protective member according to claim 1 is superposed on an image formed on a recording material so that the thermal transferable protective layer faces the image, and thermal transferability is improved. An image protection method, characterized in that a heat transferable protection layer is attached onto an image by heating from the side opposite to the protection layer, and then the thin leaf substrate is peeled off.