JP2002067479A - Ink jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording medium, which can contrive to enhance the environmental aptitude at its scrapping due to its natural degradation under the state being left after its scrapping by a method wherein both its ink accepting layer and its base material have biodegradability even under the condition that the ink jet recording medium is filled up without being incinerated or scattered in a natural environment. SOLUTION: In the recording medium, which is formed by providing the ink accepting layer on a base material, both a bonding agent and the base material are made of a biodegradable resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium, and more particularly to an ink jet recording medium having excellent biodegradability. The present invention relates to an ink jet recording medium that has been provided with biodegradability not only in a base material but also in an ink receiving layer in response to a disposal problem when the ink jet recording medium is placed in a natural environment.

[0002]

2. Description of the Related Art In recent years, with the demand for color printers,
A new printing method of the ink jet method has been developed.

As a recording medium used in this ink jet recording system, there have been conventionally used an ink jet recording medium in which a porous ink receiving layer is provided on ordinary paper or paper base material,
Translucent recording media for HP and the like have been used.

On the other hand, a film whitened by adding an inorganic pigment or another kind of polymer is used as a base material for cards, labels, display boards, white boards, and the like. A milky white film having light transmission and light diffusion properties is also used as a substrate.

In general, paper media are not sufficient for applications requiring strict dimensional stability, and proposals of providing an ink receiving layer on a film are disclosed in JP-A-64-36479 and JP-A-1-95091. It is made in gazettes and the like. For applications requiring hiding properties, Japanese Patent Application Laid-Open No. 2000-37835 proposes a white polyester film. Conventionally, in a recording medium requiring such dimensional stability, a polyester resin is usually used. Films such as diacetate resin, triacetate resin, acrylic resin, polycarbonate resin, polyvinyl chloride resin, and polyimide resin have been used as substrates.

[0006] When a product using such a plastic film is discarded after use, it is currently disposed of by incineration or landfill as waste.

However, incineration of waste materials containing plastics involves intensification of the incineration temperature due to incineration, which causes problems such as durability of incinerators, pollution of combustion gas, and the like. If scattered inside, it remains in the form as it is and becomes semi-permanent garbage, which has a problem of affecting the natural environment.

[0008] For this reason, in order to eliminate the problem of the influence of plastics on the natural environment, recently, for example, Japanese Patent Application Laid-Open No. 5-85 is disclosed.
No. 088, Japanese Patent Application Laid-Open No. 7-9788, and a card laminated with plastics that can be decomposed under natural environment such as light or underground have been devised, and some of them are currently commercialized. .

[0009] However, even if a biodegradable plastic is used as the base material, if the ink receiving layer does not have biodegradability, only the ink receiving layer remains as a waste forever and is not truly environmentally friendly. Was.

Conversely, even if a biodegradable resin such as polyvinyl alcohol is used as a binder for the ink receiving layer, a non-degradable resin such as PET or vinyl chloride is used as the base material. However, only the base material remained forever and was not environmentally friendly.

Here, the term "biodegradable" refers to a property in which a polymer is decomposed into oligomers, monomers, or even low-molecular substances by the action of enzymes produced by microorganisms existing in the environment, such as molds, bacteria, and yeasts. In the end, it is decomposed into water, carbon dioxide, methane and the like.

[0012]

As described above, in the conventional ink jet recording medium, since the non-biodegradable resin is contained in the base material or the ink receiving layer as a binder, it is environmentally friendly when discarded. There was a problem in terms.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention that a recording medium having an ink receiving layer can be buried without being incinerated after use, or can be used naturally. Even if scattered in the environment, both the ink receiving layer and the base material have biodegradability, so that they can be naturally decomposed even if left after disposal to improve the environmental suitability associated with disposal. It is to provide a recording medium.

[0014]

In order to achieve the above object, a recording coating composition according to the present invention relates to an ink jet recording method comprising providing an ink receiving layer containing a binder on a base material. In the medium, the binder and the base material are both biodegradable resins.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

According to the present invention, there is provided an ink jet recording medium comprising an ink receiving layer provided on a base material, wherein the binder and the base material are both biodegradable resins.

The present invention uses a polyvinyl alcohol and / or a cellulose derivative as a binder for an ink-receiving layer having biodegradability. It is preferable that the polymer be decomposed into oligomers, monomers, or even low-molecular substances by the action of enzymes produced by microorganisms present in the environment.

In the present invention, the base material is preferably selected from polyvinyl alcohols, vinyl alcohol copolymers, aliphatic polyesters, and cellulose derivatives.

In the present invention, it is preferable that the substrate is formed by kneading a white inorganic pigment.

Next, as a material for forming the ink receiving layer used in the recording medium of the present invention, any conventionally known material can be used. Specifically, albumin, gelatin, casein, starch, cationic starch, gum arabic, polyvinylimidazole, agar, hydrophilic natural materials such as alginate, dextrin, viscose, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, cation-modified Hydroxyethyl cellulose,
Polyvinyl alcohol, cation-modified polyvinyl alcohol, acetal-modified polyvinyl alcohol (polyvinyl acetal), polyethylene glycol, polypropylene glycol, polyacrylic acid, water-soluble alkyd, polyvinyl ether, polyvinylpyrrolidone, quaternized polyvinylpyrrolidone, polyamide, polyacrylamide,
Water-soluble or hydrophilic synthetic resins such as poly (N-vinyl-3-methylpyrrolidone), polymaleic acid copolymer, polyethyleneimine, polyethylene oxide, polyvinylimidazole, polyallylamine, polyallylamine hydrochloride, melamine resin, polyurethane, polyester and the like. At least one of these materials
Although at least one kind is used, polyvinyl alcohols and / or cellulose derivatives are particularly preferred from the viewpoints of inkjet suitability and biodegradability.

For the purpose of improving ink jet recording suitability, for example, beading resistance, blocking resistance, ink absorption, etc., the obtained ink jet recorded matter is further preserved, for example, in the case of images in a high humidity environment. For the purpose of improving bleeding, water resistance and the like, in addition to the above materials, a water-soluble low-molecular organic compound and a cationic compound, and further, a water-insoluble organic compound can be appropriately used.

The material constituting the ink receiving layer is preferably one having biodegradability like the base material, but is not necessarily limited to this. The reason is that, when viewed from the entire recording medium in the present invention, the proportion of the weight occupied by the ink receiving layer is relatively small, so even if all the constituent materials do not have biodegradability, the object of the present invention is not considered. Can be sufficiently achieved.

The water-soluble low-molecular-weight organic compound used in this case includes ethylene glycol, polyethylene glycol, poly (ethylene glycol-propylene glycol) copolymer, D-sorbitol, and a molecular weight of 5,000 or less represented by sucrose. And the like.

As the cationic compound, primary, secondary and
Compounds of the tertiary and tertiary amine salt type, for example, hydrochlorides and acetates such as laurylamine, cocoamine, stearylamine, rhodiamine; quaternary ammonium salt type compounds, for example, lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride Benzyltributylammonium chloride, benzalkonium chloride, etc .; pyridium salt type compounds, such as cetylpyridinium chloride; imidazoline type cationic compounds, such as 2-heptadecenyl-hydroxyethylimidazoline; ethylene oxide adducts of higher alkylamines; For example, dihydroxyethylstearylamine and the like can be mentioned.

Further, as the water-insoluble organic compound, an acrylic resin represented by polymethyl methacrylate;
Polyamide represented by 6,6 nylon, polyvinyl acetal represented by butyral resin, polyethylene, polypropylene, polystyrene resin, polyvinyl chloride, phenol resin, epoxy resin, polyester, polyurethane, diacetate compound, D-sorbitol / And aromatic aldehyde condensates.

Also, the physical properties of the recording medium for ink jet,
For example, in order to improve blocking resistance and the like, conventionally known organic and / or inorganic fine particles (powder, emulsion, etc.) may be added to the ink receiving layer at about 0.01 to 1.0 g / m ^2. It is possible. In addition, dispersants, lubricants, various surfactants such as defoamers, oils, pH adjusters, fluorescent dyes, preservatives, and other conventionally known additives within a range that does not reduce the performance of the recording medium in the present invention. It is possible to use.

Further, since the biodegradable binder forming the ink receiving layer is water-soluble and thus has insufficient water resistance, a crosslinking agent can be used to solve such a drawback. Any cross-linking agent generally used in the art can be used, and examples thereof include melamine derivatives, glyoxal derivatives, dimethylol urea derivatives, acetal derivatives, and triazine derivatives.

As a method for forming an ink receiving layer on a substrate, a coating solution composed of the above-mentioned material is coated with a conventionally known coating method, for example, a roll coating method, a lot bar coating method, a spray coating method, an air coating method, or the like. It can be formed by applying by a knife coating method, a microgravure coating method or the like. The thickness of the ink receiving layer is preferably from 1 to 50 μm,
It is more preferable that the thickness be 30 μm.

The polymer film used as the base material of the present invention includes methyl cellulose, ethyl cellulose,
Carboxymethyl cellulose, methoxy cellulose, hydroxy cellulose, fully (or partially) saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol,
Specific product names of films of polyvinyl alcohol, such as ethylene-vinyl alcohol copolymer and silicon-modified polyvinyl alcohol, and biodegradable films include, for example, Acero Chemical Co., Ltd.・ Film containing cellulose and starch,
Showa Polymer's Bionole is a polybutylene succinate film, Daicel Chemical Industries, Ltd.'s Placcel is a polycacrolactone film, Nippon Gohsei's Matabi is a starch / modified poval film, and Shimadzu's Lacti is Polylactic acid film and Nippon Shokubai Lunare include cellulose acetate film.

In order to improve the physical properties such as the concealing property of the resin for the base material and to reproduce the color of printing, usually, a white inorganic pigment is contained. Zinc white, lead white, zinc sulfide,
Magnesium bicarbonate, calcium light carbonate, colloidal calcium carbonate, talc, mica and the like are used.

Of these, at least one filler is mixed with one of the resins for the base material, melt-kneaded in a kneader, and then pelletized or directly dried by a T-die melt extrusion method using a T-die melt extrusion method. A material sheet can be obtained.

Further, at the time of forming a sheet, a tougher base material can be obtained by performing a stretching process with a biaxial stretching machine.

If necessary, for example, to improve the concealing property (light shielding property) and control the surface roughness of the biaxially stretched film,
In addition to the white inorganic pigment, a fluorescent whitening agent, a colored pigment, a dye, or the like may be added to control the hue of the film.

[0034]

The ink receiving layer formed on the ink jet recording medium of the present invention has conventionally used a non-decomposable resin as a binder for the ink receiving layer. By using a biodegradable resin as a binder instead of a non-degradable resin, the ink receiving layer becomes biodegradable, and the base material also uses a biodegradable resin. It does not remain semi-permanently as garbage, but is broken down and lost.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described.

Example 1 The recording medium of Example 1 has a structure in which a degradable ink receiving layer is laminated on one surface of a biodegradable base material. (Coating liquid for ink receiving layer) ・ Polyvinyl alcohol: 90 parts by weight ・ Cation-modified polyvinyl alcohol: 10 parts by weight ・ Water: 600 parts by weight (base material composition) ・ Copolymer system of polyvinyl alcohol and starch Biodegradable resin (trade name: manufactured by Novamont, Inc.) 87 parts by weight Titanium oxide 8 parts by weight Talc 5 parts by weight Dispersant 2 parts by weight L / D = 18, screw diameter 95
The mixture was melt-extruded at a temperature of 180 ° C. with a co-rotating twin-screw extruder having a diameter of 180 mm, passed through hot water at 60 ° C., pelletized, and then re-melted to obtain a white base material having a thickness of about 200 μm by a calender roll method. Thereafter, the ink receiving layer having a thickness of about 8 after drying was coated on the substrate by a bar coater method using the above coating liquid.
μm to obtain an ink jet recording medium.

<Embodiment 2> The recording medium of Embodiment 2 has a structure in which a decomposable ink receiving layer is laminated on one surface of a biodegradable base material. (Coating liquid for ink receiving layer) ・ Polyvinyl alcohol ・ ・ ・ 80 parts by weight ・ Cation-modified polyvinyl alcohol ・ ・ ・ 20 parts by weight ・ Water ・ ・ ・ 500 parts by weight (base material composition) ・ Polylactic acid (Product name: Lacti, 95 parts by weight-Titanium oxide-5 parts by weight-Dispersant-1 part by weight Resin of the above composition is L / D = 24, screw diameter 115
After pelletizing at 200 ° C. using a tandem vent-type extruder with a diameter of 200 mm, re-melting was performed and the T-die extrusion method was applied for about 2 mm.
A white substrate having a thickness of 00 μm was obtained. Thereafter, the thickness of the ink-receiving layer after drying was about 6 μm on a sheet-like polylactic acid substrate by a microgravure coating method using the above coating liquid.
Was applied to obtain an ink jet recording medium.

<Embodiment 3> The recording medium of Embodiment 3 has a structure in which a degradable ink receiving layer is laminated on one surface of a biodegradable base material. (Coating liquid for ink receiving layer) ・ Hydroxypropyl cellulose ・ ・ ・ 10 parts by weight ・ Methylolated melamine ・ ・ ・ 2 parts by weight ・ Water ・ ・ ・ 250 parts by weight (base material composition) ・ Biodegradable polyester (trade name: 88 parts by weight Titanium oxide 10 parts by weight Dispersant 2 parts by weight The above composition is L-D = 32 and the screw diameter is 115 mm. 195 as it is in the feed section of the die melt extruder
It extruded at the temperature of ° C, and obtained the white base material of about 200 micrometers thickness. Thereafter, the above-mentioned coating solution was applied by a microgravure coating method onto a sheet-like substrate so that the thickness of the ink-receiving layer after drying was about 5 μm, to obtain an ink jet recording medium.

<Embodiment 4> The recording medium of Embodiment 4 has a constitution in which a decomposable ink receiving layer is laminated on one surface of a biodegradable base material. (Coating liquid for ink receiving layer) ・ Hydroxyethyl cellulose ・ ・ ・ 10 parts by weight ・ Methylolated melamine ・ ・ ・ 2 parts by weight ・ Water ・ ・ ・ 250 parts by weight (base material composition) ・ Contains chitosan, cellulose and starch Cellulose derivative resin (trade name: Delon, manufactured by Aicello Chemical Co., Ltd.) 88 parts by weight Titanium oxide 12 parts by weight Dispersant 2 parts by weight Screw diameter 200
After pelletizing with a biaxial co-rotating extruder having a diameter of 2 mm, the mixture was re-melted and a white substrate having a thickness of about 200 μm was obtained by a T-die extrusion method. Thereafter, the above-mentioned coating solution was applied by a microgravure coating method onto a sheet substrate so that the thickness of the ink-receiving layer after drying was about 6 μm, to obtain an ink jet recording medium.

<Embodiment 5> The recording medium of Embodiment 5 has a constitution in which a decomposable ink receiving layer is laminated on one surface of a biodegradable base material. (Coating liquid for ink receiving layer) ・ Polyvinyl alcohol: 10 parts by weight ・ Methylolated melamine: 2 parts by weight ・ Water: 250 parts by weight (base material composition) ・ Polylactic acid (trade names: Lacti, Shimadzu) 95 parts by weight Titanium oxide 5 parts by weight Dispersant 1 part by weight L / D = 28, screw diameter 200
mm, pelletized with a biaxial co-rotating extruder, then re-melted, mold temperature 80 ° C, injection pressure 1250kg / c
m ² , injection speed 3 / min, cylinder temperature 200 ° C,
A white substrate having a thickness of about 2 mm was obtained by an injection molding method under the conditions of a screw diameter of 45 mm and a nozzle of 4 mmφ × 10 mm.
Thereafter, using a simultaneous biaxial stretching machine, orientation was crystallized in a preheated 90 ° C. atmosphere at a temperature of 95 ° C. at a stretching ratio of 3 × 3 and a stretching speed of 150 m / min. And
The thickness of the ink-receiving layer after drying is about 6 μm on a sheet substrate by a microgravure coating method using the above coating liquid.
m to obtain an ink jet recording medium.

Comparative Example 1 The recording medium of Comparative Example 1 has a structure in which a biodegradable ink receiving layer is laminated on one surface of a non-biodegradable base material. That is, instead of the base material which is a biodegradable resin, PET (E22-188μ)
m, manufactured by Toray Industries Inc.), and an ink receiving layer having the composition of Example 1 was provided. Thus, Comparative Example 1 was obtained.

Comparative Example 2 The recording medium of Comparative Example 2 has a structure in which a biodegradable ink receiving layer is laminated on one surface of a non-biodegradable base material. That is, instead of the base material which is a biodegradable resin, PET (E22-188μ)
m, manufactured by Toray Industries Inc.), and an ink receiving layer having the composition of Example 2 was provided.

Comparative Example 3 The recording medium of Comparative Example 3 has a configuration in which a biodegradable ink receiving layer is laminated on one surface of a non-biodegradable base material. That is, instead of the base material which is a biodegradable resin, PET (E22-188μ)
m, manufactured by Toray Industries Inc.), and an ink receiving layer having the composition of Example 3 was provided.

Comparative Example 4 The recording medium of Comparative Example 4 has a structure in which a non-degradable non-degradable ink-receiving layer is laminated on one surface of a biodegradable base material. That is, except that non-biodegradable methyl methacrylate (Paraloid A21, manufactured by Rohm & Haas) was used in place of polyvinyl alcohol as the polymer binder of the ink receiving layer,
Comparative Example 4 was obtained in the same manner as in Example 2.

<Test 1> Next, the recording medium of Example 1 was extracted in the form of a card, buried in field soil, and the state of decomposition was periodically observed. The ink receiving layer is intermittently decomposed, the shape is difficult to maintain, and the substrate remains, and after 6 months, the ink receiving layer almost disappears. Was not retained.

<Test 2> After the recording medium of Example 2 was removed in the form of a card, it was buried in field soil, and the state of decomposition was periodically observed. Two months later, the biodegradable ink receiving layer was obtained. Is decomposed intermittently, the shape becomes difficult to maintain, and the substrate remains, and after 4 months, the receiving layer almost disappears, and after 24 months, the substrate also retains its shape. There was no state.

<Test 3> After the recording medium of Example 3 was pulled out into a card form, it was buried in field soil, and the state of decomposition was periodically observed. Two months later, the biodegradable ink receiving layer was obtained. Decomposes intermittently, the shape becomes difficult to maintain, and the substrate remains, and after 8 months, the receiving layer is almost gone, and after 14 months, the substrate also retains its shape. There was no state.

<Test 4> After the recording medium of Example 4 was removed in the form of a card, it was buried in field soil, and the state of decomposition was periodically observed. Two months later, the biodegradable ink receiving layer was obtained. Is intermittently decomposed, the shape is difficult to maintain, and the substrate remains, and after 4 months, the receiving layer is almost gone, and after 12 months, the substrate also retains its shape. There was no state.

<Test 5> After the recording medium of Example 5 was pulled out in the form of a card, it was buried in field soil, and the state of decomposition was periodically observed. Two months later, the biodegradable ink receiving layer was obtained. Decomposes intermittently, the shape becomes difficult to maintain, and the substrate remains, and after 8 months, the receiving layer is almost gone, and after 24 months, the substrate also retains its shape. There was no state.

<Test 6> On the other hand, the recording medium of Comparative Example 1 was similarly pulled out in the form of a card, buried in field soil, and the state of decomposition was periodically observed. The ink receiving layer is intermittently decomposed, it is difficult to maintain the shape, and the substrate remains, and after 6 months, even though the receiving layer is almost gone, the ink receiving layer There was almost no change, and only a slight propagation of mold on the surface of the coating film was observed. Even after 24 months, the base material remained almost without decomposition.

<Test 7> Similarly, the recording medium of Comparative Example 2 was pulled out in a card form, buried in field soil, and the state of decomposition was periodically observed. The receiving layer decomposes intermittently, the shape becomes difficult to maintain, the substrate remains, and even after 4 months, the receiving layer has almost disappeared. No change was observed, and only a slight propagation of mold on the surface of the coating film was observed. Even after 24 months, the base material remained almost without decomposition.

<Test 8> Similarly, the recording medium of Comparative Example 3 was pulled out in the form of a card, buried in field soil, and the state of decomposition was periodically observed. The receiving layer decomposes intermittently, the shape becomes difficult to maintain, the substrate remains, and even after 8 months, the receiving layer has almost disappeared. No change was observed, and only a slight propagation of mold on the surface of the coating film was observed. Even after 24 months, the base material remained almost without decomposition.

<Test 9> Similarly, the recording medium of Comparative Example 4 was pulled out in the form of a card, buried in field soil, and the state of decomposition was periodically observed. There is almost no change, bacteria grow on the substrate, and 2
After the lapse of four months, the ink receiving layer remained almost completely in spite of the fact that the shape of the substrate became difficult to maintain.

When printing was performed on the recording media of these Examples and Comparative Examples using a commercially available ink jet printer, the ink had good ink jet recording suitability.

As described above, in the recording media of Comparative Examples 1 to 3, although the ink receiving layer has biodegradability, the base material itself does not have degradability, so However, there is a problem that only the substrate remains semipermanently.

On the contrary, in the recording medium of Comparative Example 4, although the base material itself has biodegradability, the ink receiving layer does not have biodegradability. Only a semi-permanent remains.

In contrast, the information recording media of Examples 1 to 5 can be said to be extremely excellent recording media because not only the base material but also the ink receiving layer has biodegradability.

Therefore, it is possible to record information as a recording medium and, at the same time, consider that the entire recording medium including the ink receiving layer has biodegradability. It can be said that it is possible to eliminate the influence on the natural environment as described above.

[0059]

As described above, the ink jet recording medium of the present invention is provided with a biodegradable ink receiving layer on at least one surface of a biodegradable base material, thereby enabling information recording as a recording medium. It has good ink jet recording suitability, and at the same time, the entire medium, including the ink receiving layer, has biodegradability. A recording medium that can be improved can be provided.

Claims (4)

[Claims] 1. A recording medium having at least a base material and an ink receiving layer, wherein both the binder and the base material constituting the ink receiving layer are biodegradable resins. 2. The ink jet recording medium according to claim 1, wherein the binder of the ink receiving layer is a resin selected from polyvinyl alcohols and / or cellulose derivatives. 3. The method according to claim 1, wherein the base material is a polyvinyl alcohol,
Vinyl alcohol copolymers, aliphatic polyesters,
The inkjet recording medium according to claim 1, wherein the inkjet recording medium is selected from a cellulose derivative. 4. The ink jet recording medium according to claim 1, wherein the base material is formed by kneading a white inorganic pigment.