JPH0784090B2 - How to protect printed matter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for recording using an aqueous ink, and more particularly to a method for protecting a print recorded by an inkjet method against light and water.

[Conventional technology]

The inkjet recording system has advantages such as low noise, easy multicolor recording, easy recording of large images, and low running cost, and has been rapidly popularized in recent years.

The recording material used there is plain paper, coated paper, or a plastic film having a porous surface layer or a non-porous hydrophobic plastic film coated with an ink receiving layer composed of organic or inorganic fine particles and a binder resin. The thing etc. which were engineered are mentioned.

Further, as a recording liquid for ink jet recording, safety,
From the viewpoint of printing characteristics, water-based ones are mainly used. Along with this, since a water-soluble dye is used as the coloring agent in the recording liquid, a hydrophilic substance is often used as the recording material.

On the other hand, printed matter is required to have high water resistance and light fastness, and these requirements are satisfied.
184, JP-A-62-59076, JP-A-62-60683, JP-A-62-202794, JP-A-62-273889, JP-A-62-2738.
A method of laminating a plastic film has been proposed as described in JP-A No. 90, JP-A-62-280085, JP-A-62-280086 and the like.

[Problems to be Solved by the Invention]

However, such a conventional laminating method has insufficient light resistance, and when the laminated film and the printed matter have the same size, or when necessary portions are cut after laminating, it is difficult to seal the edges, and the edges are difficult to seal. There is a problem that the water penetrates from the area and the printing is blurred.

[Means for Solving the Problems]

Therefore, as a result of intensive studies to solve the above problems, the present inventors have found that these problems can be solved by coating and impregnating a specific compound on the recording surface, and arrived at the present invention.

That is, an object of the present invention is to provide a method for protecting printed matter by an inkjet method, which is excellent in water resistance and light resistance. And the purpose is to apply a liquid containing a reaction product of a hydroxyl group-containing fluoropolyolefin and an isocyanate compound to a recording image surface recorded using a water-based ink on a recording material, and then press-bond a plastic film. Easily reached.

Hereinafter, the present invention will be described in detail.

The recording material used here is bond paper, electrophotographic paper, or coated paper obtained by coating high quality paper with zeolite or the like, as well as polyvinyl acetate on the surface of non-porous plastic film such as polyester, polyvinyl chloride or polystyrene. , Polyvinyl alcohol, polyvinylpyrrolidone, polyamide, polyoxazoline, polyvinylamine, polyethyleneimine, hydroxypropylcellulose, ethylcellulose, polyamide epoxy, polyester urethane, polyether urethane and other hydrophilic resins, and colloidal silica, aerosil and other ultrafine silica. , A fine powder of alumina, fine powder of zirconia, fine particles of urea-formalin resin, fine particles of benzoguanamine resin, etc. applied by a usual method such as a bar coater is used. .

Since the recording surfaces of these recording materials are both hydrophilic and porous, it is possible to print with a water-based ink jet ink, as well as the reaction product of a hydroxyl group-containing fluoropolyolefin and an isocyanate compound described below. It can be impregnated.

In the present invention, an image is recorded on the recording material described above by an inkjet method.

In this case, for the recording by the inkjet method, a conventionally known inkjet method is used, and examples thereof include a method of ejecting ink from a nozzle by a piezoelectric element or a method of ejecting ink from a nozzle by using bubbles generated by heating. . Then, after recording an image on a recording material by such an ink jet system, a liquid containing a reaction product of a hydroxyl-containing fluoropolyolefin and an isocyanate compound is applied and impregnated on the recording surface.

As the water-based ink, a conventionally known ink is used as an inkjet recording liquid, and generally contains a direct dye, a water-soluble dye such as an acid dye, an aqueous medium containing water as a main component, and various additives which are added as necessary. To do.

As the hydroxyl group-containing fluoropolyolefin, for example,
Obtained by copolymerizing a fluoroolefin such as tetrafluoroethylene or hexafluoropropylene with vinyl acetate, followed by saponification, or by copolymerizing the fluoroolefin with an acrylic ester such as hydroxyethyl acrylate or hydroxyethyl methacrylate. You can use whatever is available. Specifically, products such as Fluoronate K-700 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) and Fluoronate K-701 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) are commercially available. Can also be used.

As the isocyanate compound, an adduct of an aliphatic diisocyanate or an alicyclic diisocyanate compound (adduct with a divalent or trivalent polyhydric alcohol, a trimer having an isocyanurate ring, an adduct with water) is used. .

Particularly, a trimethylolpropane adduct of hexamethylene diisocyanate and an adduct of hexamethylene diisocyanate and water are preferable.

Both the hydroxyl-containing fluoropolyolefin and the isocyanate compound can be used in the state of being dissolved or dispersed in an organic solvent such as benzene, toluene, xylene, butyl acetate, methyl isobutyl ketone, isopropanol, and cellosolve acetate. The concentration of the hydroxyl group-containing fluoropolyolefin or isocyanate compound in the liquid is 20 to 70% by weight, preferably 30 to 50% by weight.

The amount ratio of the polyolefin and the isocyanate compound is a hydroxyl group in the polyolefin, based on the NCO groups of the isocyanate compound, 0.8 to 1.2 molar ratio, preferably 0.9 to
1.1 molar ratio.

The reaction between the hydroxyl group-containing fluoropolyolefin and the isocyanate compound is carried out in the presence or absence of a tin compound such as dibutyltin laurate or an amine compound such as triethylenediamine as a catalyst at 15 to 80 ° C.
It takes 6 hours.

The above reaction is performed before coating and impregnating the recording surface,
The reaction product may be applied to the recording surface or may be reacted on the applied surface.

Here, the thickness of the overcoat layer formed of the reaction product of the fluoropolyolefin and the isocyanate compound is 2 to 20 μm, preferably 5 to 15 μm, and the thickness is less than 2 μm. The transparency is likely to be insufficient and the cost is increased, which is not preferable.

Further, as the plastic film to be further pressure-bonded on the overcoat layer, polyethylene, polypropylene,
Polyvinyl butyral, polyvinyl acetate, polyacrylic acid ester, polystyrene, polyamide such as nylon, polyester such as polyethylene terephthalate, and thermoplastic resin such as polyvinylidene fluoride can be used.

The temperature for thermocompression bonding is preferably 60 to 150 ° C.

In order to further enhance the light resistance of the printed matter, it is effective to add an ultraviolet absorber to the overcoat layer.

UV absorbers such as Uvinul D-49 (trade name, manufactured by BASF) Cyasorb DV-9 (trade name, manufactured by ACC) such as Tinuvin P (trade name, manufactured by Ciba-Geigy) Benzotriazole-based compounds can be used.

The amount used is 1 to 10% by weight, preferably 2 to 5% by weight, based on the solid content of the overcoat layer.

〔The invention's effect〕

According to the present invention, after impregnating the reaction product of the hydroxyl group-containing fluoropolyolefin and the isocyanate compound into the porous specific recording material, the laminate film is pressure-bonded, so that the laminate film and the printed matter have the same size, or Even if a necessary portion is cut after laminating, water does not penetrate from the end portion, the water resistance of the printed matter is remarkably improved, and the workability in pressure-bonding the laminated film is also improved.

〔Example〕

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

In the following examples, "part" means "part by weight".

Example 1 was mixed to adjust Coating Formulation Water 75 parts Polyvinyl pyrrolidone (polymerization degree 2000) 12.5 parts Urea-formalin resin fine smear 12.5 parts Total 100 parts The above components of the recording material, pulverized and dispersed in a ball mill At the very least, the coating liquid was adjusted.

On a polyvinyl chloride sheet having a thickness of 100μ, a bar coater is used to apply the above coating solution to a dry thickness of 20μ,
The recording material was adjusted.

Printing was performed using an inkjet printer I-720 (trade name, manufactured by Sharp Corporation) on the recording material prepared as described above.

Formation of Protective Layer 100 parts of Fluoronate K-700 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) and trimethylolpropane adduct of hexamethylene diisocyanate are formed on the above-mentioned printed matter 20
A mixture of 140 parts of a toluene solution containing 100 parts of a toluene solution was applied using a bar coater to a dry thickness of 5 μ, and then the mixture was heated at 80 ° C. for 3 hours.
Heat treatment was performed for a minute. Further, aging treatment was performed at 80 ° C. for 1 hour. A polyvinylidene fluoride film having a thickness of 50 μ was superposed on this and thermocompression bonded.

Light resistance and water resistance test A 200-hour test was performed using a sunshine super long life weather meter (trade name, manufactured by Suga Test Instruments Co., Ltd.). As a result, there was no image bleeding and no decrease in coloring density, and both light resistance and water resistance were good.

Example 2 Preparation of Recording Material Coating Composition: Water 75 parts Polyvinyl alcohol (Polymerization degree 4000) 7.5 parts Polyvinylamine (Polymerization degree 1000) 5 parts Colloidal silica 12.5 Total 100 parts The above components were mixed, The coating liquid was prepared by pulverizing and dispersing with a ball mill.

A 100 μm-thick polyethylene terephthalate sheet was coated with the above coating solution using a bar coater to a dry thickness of 20 μm to prepare a recording material.

Printing was performed using an inkjet printer I-720 (trade name, manufactured by Sharp Corporation) on the recording material prepared as described above.

Formation of protective layer 100 parts of Fluoronate K-701 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) on top of the above printed matter, Cyasorb UV-
A mixture of 2 parts of 9 (trade name, manufactured by ACC) and 140 parts of a toluene solution containing 20 parts of a trimer of hexamethylene diisocyanate was applied to a dry thickness of 15 μm using a bar coater, and then 80 ° C. Was heat-treated for 3 minutes. Further
Aging treatment was performed at 80 ° C. for 1 hour. Thickness on this
A 50 μ polypropylene film was overlaid and thermocompression bonded.

Light resistance and water resistance test A 200-hour test was performed using a sunshine super long life weather meter (trade name, manufactured by Suga Test Instruments Co., Ltd.). As a result, there was no image bleeding and no decrease in coloring density, and both light resistance and water resistance were good.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location B41M 7/00 // B32B 27/10 8413-4F 27/40 7421-4F

Claims (1)

[Claims] 1. A method comprising applying a liquid containing a reaction product of a hydroxyl group-containing fluoropolyolefin and an isocyanate compound onto the surface of a recording image recorded with a water-based ink on a recording material and then impregnating it with a plastic film. How to protect printed matter