JP3070478B2 - Surface treated plastic film and ink jet recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-treated plastic film useful as various labels, delivery slips, recording paper for printers and the like. The present invention relates to a surface-treated plastic film which is excellent in selective absorption and diffusion prevention for alcohol-based ink, and has drastically improved writing and printing properties. Further, the present invention relates to an ink jet recording medium using the surface-treated plastic film and capable of printing high-quality images.

[0002]

2. Description of the Related Art Plastic films are superior to natural paper in terms of water resistance, moisture absorption dimensional stability, planar smoothness, gloss and sharpness of printed matter, and mechanical strength. As synthetic paper instead of paper, for example, wrapping paper,
It has been widely used in fields such as labels, maps, posters, business cards, delivery slips, and recording paper for various printers.

[0003]

However, a normal plastic film has a smooth surface and has almost no absorbability with respect to water-based and alcohol-based inks.
There is a problem that writing performance with a ballpoint pen, a water-based pen or the like is poor. In addition, it has been pointed out that water-based and alcohol-based inks are hardly absorbed, so that the drying properties of the inks are poor, and furthermore, the inks are blurred and cannot be read.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the absorbability of a plastic film to a water-based or alcohol-based ink in the surface layer, to enhance the writing performance with an aqueous pen or the like, the receptivity of a stamp ink or vermilion, etc. It is an object of the present invention to provide a surface-treated plastic film that can be used without any problem as a synthetic paper replacing a natural paper such as labels, delivery slips, recording paper for various printers, and information recording paper. Another object of the present invention is to provide an ink jet recording medium using the surface-treated plastic film and capable of performing high-quality recording.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have completed the present invention. That is, the present invention is as follows. A surface-treated plastic film in which a surface coating layer is formed on at least one surface of a plastic film, wherein each of the surface-treated plastic films has a bleeding index of 1.0 to 1. 2. The surface-treated plastic film which is 2. The surface-treated plastic film according to the above, wherein the surface coating layer contains, as essential components, inorganic particles that have been subjected to an organic surface treatment and / or an inorganic surface treatment, a polymer wax, and an aqueous resin or an organic solvent-soluble resin. The surface-treated plastic film according to the above, wherein the surface coating layer contains, as essential components, inorganic particles subjected to an organic surface treatment and / or an inorganic surface treatment, a polymer wax, and an aqueous resin. The surface-treated plastic film according to any one of-, wherein the plastic film is a polyester-based film. The polyester film contains at least one kind of polyester and a thermoplastic resin incompatible with the polyester,
The surface-treated plastic film according to the above, wherein the surface-treated plastic film contains fine voids by being stretched in at least one axial direction, and has an apparent specific gravity of 0.8 to 1.3. The surface-treated plastic film according to any one of-, wherein the light transmittance is 30% or less and the in-plane birefringence is -0.02 or more and +0.04 or less. An ink jet recording medium comprising an ink receiving layer provided on a surface coating layer of the surface-treated plastic film described in any one of the above.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The surface-treated plastic film of the present invention has a surface coating layer on at least one side of the plastic film, and the bleeding index of the surface-treated plastic film side with respect to aqueous and alcohol-based inks. Are set to 1.0 to 1.2, respectively. When the ink bleeding index is less than 1.0, for example, in the case of seal ink, a phenomenon occurs in which the seal ink is repelled and the seal imprint becomes difficult to read due to thinning or breakage. However, the seal ink bleeds and becomes difficult to read, and does not serve as a seal. The same applies to printing inks and writing inks.

The water-based ink used in the present invention is "Replenishment Ink for Bando Stamp: Vermilion" manufactured by Bando Co., Ltd., and water / polymer glycol / alcohol / dye = 40.
/ 30/20/10 (% by weight). Further, the alcohol-based ink is "supplementary ink for shachihata stamp: S-1 black" manufactured by Shachihata Industry Co., Ltd., and alcohol / water / dye / surfactant / others = 50-60 / 2.
0 to 30/5 to 10/1 to 3/1 to 3 (% by weight).

In the present invention, the ink bleeding index is
It refers to the value measured by the following method. That is, a sample film is set horizontally on a sample stand of a stereo microscope equipped with a camera so that the surface coating layer side is facing up, and 0.6 μl of a water-based or alcohol-based ink is applied to the upper surface of the sample film with a micro syringe. When the ink is dropped, the image area of the ink adhered immediately after dropping (S ₁ ) and the image area of the ink adhered after 30 minutes (S ₂ )
From photos taken under the same conditions. The S thus obtained for each of the water-based and alcohol-based inks
With ₁ and S _2, we obtain the ink spreading index for each aqueous and alcohol inks by the following equation. Ink spreading index = S ₂ / S ₁

The surface-treated plastic film of the present invention that satisfies such a bleeding index preferably has an organic surface treatment and / or an organic surface treatment on at least one side of the plastic film.
Alternatively, it can be obtained by providing a surface coating layer containing, as essential components, inorganic particles subjected to inorganic surface treatment, a polymer wax, and an aqueous resin or an organic solvent-soluble resin.

The inorganic particles used in the present invention are not particularly limited. For example, silica, calcium carbonate, calcium sulfate, barium sulfate, magnesium hydroxide, aluminum hydroxide, talc, zeolite, alumina, titanium dioxide, zinc oxide, etc. Particles. Of these, silica particles are particularly preferred. The particle diameter of the inorganic particles is preferably in the range of 0.5 to 10 μm, more preferably in the range of 1.0 to 5.0 μm. The inorganic particles can be used alone or in combination of two or more. Of course, two or more kinds of particles having different particle diameters can be used in combination.

In the present invention, the organic surface treatment and / or the inorganic surface treatment applied to the surface of the inorganic particles means that the surface of the particles is partially hydrophobized to reduce the secondary cohesion of the particles and to disperse the particles. This is carried out to enhance the spreadability and to control the diffusion of the water-based and alcohol-based inks.

Examples of the organic surface treatment include silylation with a coupling agent (for example, vinyltris (β-methoxyethoxy) silane, 3-aminopropyltriethoxysilane, etc.) and higher fatty acids (for example, stearic acid, palmitic acid, etc.). ), A method of treating with a saturated hydrocarbon or a resin (for example, paraffin wax, stearic acid amide, a silicone resin, a fluororesin, etc.). Examples of the inorganic surface treatment method include a method of performing a surface reaction or ion exchange with an inorganic coupling agent, a metal alkoxide, a metal ion, or the like. Among them, a method using a magnesium-based treating agent is particularly preferable.

Specifically, these surface treatment methods include a method of coating the surface treatment agent used in the above method on the surface of the inorganic particles by spray coating or the like, or a method in which the inorganic particles are immersed in a liquid of the surface treatment agent. To the surface of the inorganic particles.

The polymer wax which is an essential component in the surface coating layer generally has low wettability with water,
It is a known polymer wax that can be dispersed or emulsified in water, and examples thereof include polyethylene wax, polypropylene wax, acrylic wax, and fatty acid wax. Among these high molecular waxes, particularly preferable are high molecular affinity waxes having high affinity for solvents and having no sticky feeling and having excellent heat dispersion stability, especially polyethylene waxes and acrylic waxes. Is optimal as a control agent for the bleeding index. Here, the polyethylene-based wax, the polypropylene-based wax and the like have a number average molecular weight of 1,000 to 20,000, preferably 1,000 to 1,000.
0000. The acrylic wax has a number average molecular weight of 5,000 to 5,000,000, preferably 10,000 to 3,000,000, more preferably 1,000.
It is in the range of 00 to 2,000,000.

As another essential component constituting the surface coating layer, an aqueous resin or a resin soluble in an organic solvent is used.
The aqueous resin is a water-soluble and / or water-dispersible resin, for example, polyvinyl alcohol, ion-modified polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyurethane, urethane oligomer containing blocked isocyanate, starch, gelatin, casein, carboxymethylcellulose. And hydroxyethyl cellulose, copolymerized polyester, polyacrylic acid, acrylic acid-based copolymer, and polyvinyl acetate. Further, the organic solvent-soluble resin is a resin that is dissolved in a single or mixed solvent of toluene, methyl ethyl ketone, and ethyl acetate, such as a copolymerized polyester, a polyurethane, an acrylic copolymer, and a styrene-butadiene copolymer. Can be These can be used alone or in combination of two or more, if necessary. Among them, it is preferable to use an aqueous resin from the viewpoint of safety and hygiene and workability.

The mixing ratio of the inorganic particles to the aqueous resin or the organic solvent-soluble resin is preferably in the range of 25 to 250 parts of the inorganic particles based on 100 parts of the aqueous resin or the organic solvent-soluble resin in terms of solid content. , More preferably 65
It is in the range of ~ 150 parts. If the compounding ratio of the inorganic particles is less than 25 parts by weight, the ink absorbency tends to decrease, while if it exceeds 250 parts by weight, the abrasion resistance of the surface coating layer tends to decrease.

The compounding ratio of the high molecular wax to the aqueous resin or the organic solvent-soluble resin is from 0.1 to 100 parts by weight of the high molecular wax to 100 parts of the aqueous resin or the organic solvent-soluble resin in terms of solid content. A range of 5.0 parts is preferred,
More preferably, it is in the range of 0.5 to 1.5 parts. If the amount of the polymer wax is less than 0.1 part by weight, the bleeding of the ink tends to increase, while if it exceeds 5.0 parts by weight, the ink absorbency tends to decrease.

The surface coating layer containing the above three components as essential components improves the additional functions (for example, scratch resistance, antistatic property, water resistance, etc.) as the outermost layer of the surface-treated plastic film. For this purpose, it is also effective to include various additives, for example, a crosslinking agent (melamine-based, isocyanate-based, etc.), an antistatic agent, and the like, if necessary.
Among the antistatic agents, organic low-molecular antistatic agents, in particular, tend to promote ink diffusibility and increase bleeding. For example, inorganic antioxidants such as Zn-Sn compounds, titanate compounds, and phosphorus-based compounds It is preferable to use a system antistatic agent or a polymer antistatic agent.

The thickness of the surface coating layer is preferably 0.1 μm or more. If it is less than 0.1 μm, the ink absorbency tends to be insufficient. Considering cost merit, etc.
A range of 5 to 5.0 μm is more preferable.

The plastic film used in the present invention is not particularly limited, and examples thereof include polyolefin, polyester, polyamide, polyimide, polycarbonate, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride and the like.
And a polymer film using two or more species. Among these, a polyester film is particularly preferred. The thickness of the plastic film is not particularly limited, but is preferably in the range of 1 to 5000 μm, more preferably 5 to 500 μm, from the viewpoint of securing general strength characteristics as synthetic paper.

The polyester preferably used as the plastic film material includes aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid or esters thereof, ethylene glycol, diethylene glycol, 1,4-butanediol, Examples include polyesters produced by polycondensation with glycols such as pentyl glycol. The polyester may be a method of directly reacting an aromatic dicarboxylic acid and a glycol, a method of subjecting the alkyl ester of an aromatic dicarboxylic acid to a transesterification reaction with a glycol followed by polycondensation, or a method of performing a diglycol ester of an aromatic dicarboxylic acid. Can also be produced by a method of polycondensation.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate and polyethylene-2,6-naphthalate. The polyester may be a homopolymer, or may be a copolymer obtained by using two or more kinds of acid components and / or glycol components. In the present invention, in particular, ethylene terephthalate unit, butylene terephthalate unit or ethylene-2,6-naphthalate unit accounts for at least 70 mol% of the entire polyester.
Preferably 80 mol% or more, more preferably 90 mol%
The polyesters described above are preferred. By selectively using such a polyester as a plastic film material, it is possible to obtain a surface-treated plastic film which is more excellent in dimensional stability and heat resistance.

Further, as the film material, a material obtained by blending at least one thermoplastic resin incompatible with the polyester together with the above-mentioned polyester is used. After forming this into a film, at least a method described below is used. By performing uniaxial stretching treatment, and preferably biaxially stretching in the vertical and horizontal directions, a large number of fine cavities are formed inside the film,
The apparent specific gravity of the surface-treated plastic film is 0.8 ~
Polyester films (films containing fine voids) that can be set to 1.3 are extremely suitable as plastic films used in the present invention.

Here, the thermoplastic resin incompatible with the polyester is blended as a cavity developing agent for forming fine voids in the polyester film to enhance flexibility, lightness, and drawing properties. It can be used without any particular limitation as long as it is incompatible with the polyester. That is, since the thermoplastic resin is incompatible with the above-mentioned polyester, it is dispersed in the polyester in the form of fine particles, and peels off at the interface with the polyester at the time of stretching to become a cavity forming source.

As the thermoplastic resin, for example, a polystyrene resin (for example, isotactic polystyrene,
Syndiotactic polystyrene, atactic polystyrene, styrene-butadiene copolymer, acrylonitrile-butadiene styrene copolymer, impact-resistant polystyrene (mixture of styrene and olefin rubber), polyphenylene ether resin, polyolefin resin (for example, Polymethylpentene, polypropylene, polyethylene, cyclic olefin polymer, etc.), polyacrylic resin, polycarbonate resin, polysulfone resin,
Cellulose resins and the like can be mentioned. Among them, particularly preferred are polystyrene resins and polyolefin resins such as polymethylpentene and polypropylene.

The amount of the thermoplastic resin to be incorporated into the polyester varies depending on the target amount of cavities formed in the plastic film and the stretching conditions, but is preferably in the range of 3 to 40% by weight based on the whole plastic film. ,
Particularly, 5 to 15% by weight is preferable. If the amount is less than 3% by weight, there is a limit in increasing the amount of cavities formed, and it tends to be difficult to obtain the flexibility, light weight, or drawing property imparted to the plastic film by forming cavities. Conversely, if it exceeds 40% by weight, the heat resistance, strength and stiffness of the plastic film tend to be easily impaired, in addition to the tendency of the stretchability to decrease. The above thermoplastic resins can be used alone or in combination of two or more.

In addition, inorganic or organic particles may be added to the plastic film used in the present invention, if necessary, in order to improve the concealing property and the drawing property. Examples of the inorganic particles include silica, kaolinite, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, and titanium dioxide. As the organic particles, for example, organic white pigment,
Particles of benzoguanamine, cross-linked polystyrene, cross-linked acrylic resin and the like can be mentioned.

In the present invention, the plastic film may be a single-layer film, or may be a composite film having two or more layers depending on the application. Although the method for producing the composite film is not particularly limited, from the viewpoint of productivity and the like, the raw materials of each layer are extruded from separate extruders, guided into one die, and an unstretched film is obtained. Lamination by a so-called co-extrusion method in which at least one axis is oriented is most preferable.

[0029] The surface-treated plastic film of the present invention comprises:
A surface coating layer containing, as essential components, inorganic particles subjected to the organic surface treatment and / or the inorganic surface treatment as described above, a polymer wax, and an aqueous resin or an organic solvent-soluble resin is formed.

Among them, the surface-treated plastic film using the fine void-containing film has an apparent specific gravity in the range of 0.8 to 1.3, preferably 1.0 to 1.25, as described above. More preferably, 1.05-1.
The range is 25. If the apparent specific gravity is less than 0.8, the void content becomes excessive, the strength of the surface-treated plastic film tends to be insufficient, and cracks and wrinkles tend to occur on the surface of the surface-treated plastic film. Conversely, if the apparent specific gravity exceeds 1.3, the void content becomes insufficient,
Cushioning properties, flexibility, and drawing properties tend to decrease.

The apparent specific gravity can be adjusted by the type and amount of the cavity developing agent, that is, the thermoplastic resin incompatible with the polyester, and the film-forming conditions, especially the stretching conditions.

Here, the apparent specific gravity was measured as follows. 5.00c of surface-treated plastic film
It was accurately cut out into a square of mx 5.00 cm, its thickness was measured at 50 points, the average thickness was set to tμm, and its weight was measured to 0.1 mg to be wg, which was calculated by the following formula. Apparent specific gravity = w × 10000 / (5 × 5 × t)

The surface-treated plastic film of the present invention using a plastic film containing or not containing fine cavities has a light transmittance of 30% or less and an in-plane birefringence of -0.02 or more and +0.04 or less. Are preferred.

That is, the surface-treated plastic film of the present invention has a light transmittance of preferably 30% or less, more preferably 20% or less, and still more preferably 15% or less, in order to enhance suitability as synthetic paper. If the light transmittance exceeds 30%, the back will be seen through, and the appearance of the printed matter may be hindered.

The light transmittance can be adjusted by adjusting the content of the fine cavities and the amount of the added particles.

Here, the light transmittance is JIS-K671.
4, in accordance with the Poick integrating sphere formula H.4. T. The total light transmittance of the surface-treated plastic film was measured using an R meter (manufactured by Nippon Seimitsu Optical Co., Ltd.).

The surface-treated plastic film of the present invention preferably has an in-plane birefringence of -0.02 to +0.04, more preferably 0 to +0.03. By making the in-plane birefringence -0.02 or more, preferably 0 or more, the film becomes a substantially isotropic film,
The film can be made less likely to tear in the lateral direction. However, when the in-plane birefringence exceeds +0.04, on the contrary, the film tends to be vertically torn, which is likely to be broken at the time of slitting the film or to be easily cracked in the longitudinal direction at the time of cutting. There is. Further, the in-plane birefringence is -0.0.
If the value is less than 02 or more than +0.04, wrinkling or curling tends to occur when printing with a printer or the like. Here, the fact that the in-plane birefringence is + (or-) means that the history of longitudinal stretching is larger (or smaller) than the history of transverse stretching, and a so-called bowing phenomenon at the time of transverse stretching. May be accompanied by a slight distortion of the main axis of the refractive index.

Here, the in-plane birefringence was measured as follows. 10cm × surface treated plastic film
It is cut into a size of 10 cm, and its weight W (g) is weighed. Then, from the density ρ (g / cm ³ ) in the case where no void exists inside the film, the actual thickness T (cm) of the film irrespective of the void content is calculated by the following equation. T = W / (ρ × 100) Next, using a molecular orientation meter MOA-2001A (manufactured by Kanzaki Paper Co., Ltd.) and substituting the thickness T obtained above, the refractive index in the microwave region is set to the longitudinal main axis. The in-plane birefringence was determined by the following equation along the lateral main axis. In-plane birefringence = longitudinal principal axis refractive index-transverse principal axis refractive index The density ρ was calculated from the composition ratio of each component constituting the surface-treated plastic film and its density.

The method for producing the plastic film used in the present invention is not particularly limited. In particular, as a method for producing the fine void-containing film, an unstretched film obtained by molding a mixture containing a polyester and a thermoplastic resin incompatible with the polyester into a film is formed in one or preferably multiple stages in the longitudinal direction. After stretching to 3.0 times or more, a relaxation treatment of 3% or more is performed in the longitudinal direction, and then a transverse stretching is performed at a magnification equal to or more than the longitudinal stretching ratio after the relaxation treatment, and then heat treatment is performed.

First, in the first longitudinal stretching step, longitudinal stretching is performed in the running direction of the film while appropriately heating between two or many rolls having different peripheral speeds. As the heating means at this time, a method using a heating roll, a method of heating with hot air, radiant heat or the like in a non-contact state with a roll or the like can be adopted. Alternatively, these can be used in combination. However, in this longitudinal stretching step, in order to effectively cause peeling at the interface between the polyester and the thermoplastic resin which is incompatible with the polyester and efficiently develop cavities in the film, the stretching temperature should be (Tg + 10) ° C. (Tg + 50) ° C
(Tg: glass transition temperature of polyester), and it is preferable to perform longitudinal stretching at a stretching ratio of 3.0 times or more, preferably 3.2 to 5.0 times. If the longitudinal stretching ratio is less than 3.0 times, it is difficult to sufficiently develop fine cavities inside the film, and it tends to be difficult to reduce the apparent specific gravity of the finally obtained surface-treated plastic film to 1.3 or less. is there. On the other hand, when the longitudinal magnification exceeds 5 times, it is difficult to sufficiently perform the subsequent relaxation treatment, and it is substantially difficult to reduce the in-plane birefringence of the surface-treated plastic film to 0.04 or less.

After the longitudinal stretching, a relaxation treatment of 3% or more, preferably 5% or more in the longitudinal direction is performed. The more preferable relaxation rate varies depending on the longitudinal stretching ratio performed before the relaxation, but it is preferable to set the longitudinal stretching ratio after the relaxation to be 2.8 to 3.5. If the relaxation rate is set to 3% or more, the in-plane birefringence becomes -0.02 to +0.04.
It is possible to industrially stably produce the surface-treated plastic film. On the other hand, if the relaxation rate is less than 3%, the transverse stretchability performed in the next step is significantly deteriorated, and it tends to be difficult to produce a film having an in-plane birefringence of -0.02 to +0.04. . If the surface-treated plastic film has an apparent specific gravity of more than 1.3 (using a film having a small content of fine voids), it is possible to impart isotropy without performing such relaxation treatment.
As described above, in order to produce a light-weight, flexible, and low-density microvoided film having excellent drawing properties, it is preferable to perform the above-described relaxation treatment.

As described above, the preferred longitudinal stretching ratio after the longitudinal relaxation treatment is 2.8 to 3.5. When the longitudinal stretching ratio is less than 2.8, the relaxation is poor and tends to be uneven. ,
A homogeneous film tends to be difficult to obtain, and the in-plane birefringence of the finally obtained surface-treated plastic film tends to be less than -0.02. vice versa,
If the longitudinal stretching ratio after relaxation exceeds 3.5, poor stretching tends to occur during transverse stretching, and the in-plane birefringence of the surface-treated plastic film tends to exceed +0.04.

As a method of performing the relaxation treatment, the longitudinally stretched film is once cooled and then reheated to about 80 to 150 ° C. in a heating device such as an oven. A method of relaxing by reheating between groups, a method of relaxing between a driving roll group or a free roll group heated to about 60 to 100 ° C., and a method of appropriately combining these methods. Can be adopted. Among these, particularly preferred is a relaxation treatment method mainly comprising a method of performing a relaxation treatment without cooling immediately after longitudinal stretching, and according to this method, a heat loss is small and a more uniform relaxation treatment is efficiently performed. It can be carried out.

After the relaxation treatment, the film is introduced into a tenter, and is subjected to a transverse stretching at a magnification equal to or greater than the longitudinal stretching magnification after the relaxation treatment, followed by heat treatment. The preferred transverse stretching temperature is not less than the maximum temperature of longitudinal stretching / relaxation treatment and not more than (Tm-10) ° C (Tm: melting point of polyester). When the transverse stretching ratio is lower than the longitudinal stretching ratio after the relaxation treatment, the in-plane birefringence of the obtained surface-treated plastic film tends to be hardly reduced to +0.04 or less. Although the upper limit of the transverse stretching ratio is not particularly limited, the in-plane birefringence of the surface-treated plastic film finally obtained under stable stretchability is surely −
To make it 0.02 or more, (longitudinal stretching ratio after relaxation treatment +
1.0) times or less.

The biaxially stretched film thus obtained is preferably subjected to a heat treatment as required. The heat treatment is preferably performed in a tenter, and the heat treatment temperature is preferably in the range of (Tm-50) to Tm ° C. Further, in parallel with the heat treatment, re-lateral stretching or transverse relaxation treatment can be performed.

As a method for producing the surface-treated plastic film of the present invention, that is, a method for forming a surface coating layer on the surface of the plastic film obtained as described above for improving the writing and printing properties, a coating method is used. General, specifically, gravure coat method, kiss coat method, dip method, spray coat method, curtain coat method, air knife coat method, blade coat method,
A reverse roll coating method and the like can be mentioned. As the timing of application, any method such as a method of applying before stretching a plastic film, a method of applying after stretching in a longitudinal direction, and a method of applying to a film after orientation treatment may be adopted. In order to enhance the adhesion between the plastic film and the surface coating layer, the most preferable is to apply the coating solution to at least one surface of the uniaxially stretched plastic film by the above-mentioned coating method, and then to make a right angle to the further uniaxial stretching direction. This is an in-line coat extending in the direction of.

The surface-treated plastic film of the present invention thus obtained has less water-based and alcohol-based ink bleeding, is more excellent in drawing properties and printability, and is superior to a conventional plastic film practically used as synthetic paper. In addition, it shows excellent properties in the receptivity of stamp ink and seal vermilion, and also has excellent transportability in various printers, and furthermore, solvent type ink, aqueous type ink used for various printing, and Excellent adhesion to various inks such as UV curable inks and improved adhesion to toners such as barcode labels. Extremely excellent performance as various labels, barcode labels, delivery slips, various printer papers, information recording paper, etc. Demonstrate.

A surface-treated plastic film having a surface-coating layer formed on at least one surface of a plastic film, wherein each of the surface-treated plastic films has a bleeding index of 1.0 for water-based and alcohol-based inks. A surface-treated plastic film whose surface coating layer is preferably organic and / or inorganic surface-treated, a polymer wax, an aqueous resin or an organic solvent. The ink jet recording material of the present invention can be obtained by using a surface-treated plastic film containing a molten resin as an essential component. That is, the ink jet recording medium of the present invention,
An ink receiving layer is provided on the surface coating layer of the surface-treated plastic film provided with the surface coating layer as described above.
By using such a surface coating layer, it is possible to obtain an ink jet recording body with less ink bleeding,
Also, the adhesion of the ink receiving layer to the surface-treated plastic film is improved.

The resin component constituting the ink receiving layer is not particularly limited as long as it absorbs ink. For example, polyvinyl alcohol, acrylic resin, styrene-acrylic copolymer, ethylene-vinyl acetate copolymer,
Starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethyl cellulose, polyvinyl pyrrolidone, polyacrylamide, polyester, phenolic resin, melamine resin, epoxy resin, styrene-butadiene rubber, and the like,
One or more of these can be used. The ink receiving layer preferably contains a melamine resin, an epoxy resin, a polyurethane resin having an isocyanate group, or the like, whereby the degree of curing of the ink receiving layer is increased and the water resistance is improved. The thickness of the ink receiving layer is not particularly limited, but is preferably 3 to 50 μm, more preferably 5 to 50 μm.
25 μm.

The ink receiving layer is made of silica, kaolinite, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, titanium oxide, organic white pigment, benzoguanamine, cross-linked polystyrene, cross-linked acrylic resin, water Particles such as aluminum oxide may be blended.

The method for forming the ink receiving layer is as follows.
Gravure coat method, kiss coat method, dip method,
Conventional methods such as a spray coating method, a curtain coating method, an air knife coating method, a blade coating method, and a reverse roll coating method can be applied.

[0052]

EXAMPLES Hereinafter, the structure and operation and effect of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and the present invention is applicable to the above and following points. It is, of course, possible to carry out the present invention with appropriate modifications within the scope of the invention, and all of them are included in the technical scope of the present invention. The methods for measuring and evaluating various physical properties and performances employed in the following examples are as follows.

(1) Intrinsic viscosity of a film material A resin to be a film material is dissolved in a mixed solvent of phenol (6 parts by weight) and tetrachloroethane (4 parts by weight),
It was measured at 30 ° C.

(2) Ink bleeding index Water-based ink ("Bando stamp replenishment ink: Zhu" manufactured by Bando Co., Ltd., sold as of January 1, 1995) or alcohol-based ink ("Shachihata Stamp" manufactured by Shachihata Industry Co., Ltd.) Replenishment ink: S-1 black ", 1995, 1
Month day now on sale) and a 0.6 micron l weighed with a microsyringe and weighed to the surface (the surface coating layer side) of the preset sample film on the sample stage of the stereomicroscope with camera attached (Nikon UFX) Ink Is dropped. The area of the ink-adhered image immediately after dropping (S ₁ ) and the area of the ink-adhered image after 30 minutes (S ₂ ) were determined from photographs taken under the same conditions. Using S ₁ and S ₂ obtained for each of the water-based and alcohol-based inks, the ratio of the ink adhering areas was calculated by the following formula, and the ratio was defined as the bleeding index for each of the water-based and alcohol-based inks. Ink spreading index = S ₂ / S ₁

(3) Printability Sheet-fed offset printing press (Ricoh Auto Printer AP37)
00, manufactured by Ricoh Co., Ltd.) and an oxidation polymerization type ink (GRAF-G
(Sumi, Dai Nippon Ink Co., Ltd.) were actually printed on the surface of each sample film (surface coating layer side), and the inking property of the solid portion was visually evaluated. A state in which the ink was transferred uniformly and no spots was indicated by “○”, and a state in which the ink transferred spots and the density was low was indicated by “x”.

(4) Writability by Water-based Ballpoint Pen After writing on the sample surface using a water-based ballpoint pen (Mitsubishi Uniball / VB106Z, manufactured by Mitsubishi Pencil Co.), the bleeding state of the written characters after 16 hours was visually evaluated. . ○ indicates that the written character can be identified, and x indicates that it cannot be identified. The writing comfort during writing was evaluated by writing straight and curved lines. Here, those that can be written smoothly without being caught are marked with “○”.

(5) Apparent specific gravity The surface-treated plastic film was 5.00 cm × 5.0.
It was accurately cut out into a square of 0 cm, the thickness was measured at 50 points, the average thickness was set to tμm, and the weight was measured to 0.1 mg and set to wg, which was calculated by the following equation. Apparent specific gravity = w × 10000 / (5 × 5 × t)

(6) Light transmittance According to JIS-K6714, a Poick integrating sphere formula
T. The total light transmittance of the film was measured using an R meter (manufactured by Nippon Seimitsu Optical Co., Ltd.). The smaller this value is, the higher the concealment property is.

(7) Presence or absence of curl due to heat An anchor layer having the following composition is provided on the surface coating layer of each surface-treated plastic film, and an image receiving layer having the following composition is further provided thereon. S
CAN CH-5504 (manufactured by Seiko Electronic Industry Co., Ltd.)
Was used to actually output the image from the video. At this time, it was evaluated as x when curl was confirmed in the printed matter output, and as ○ when curl was not observed. (Anchor layer) A sulfonic acid group-containing copolymerized polyester (“Vylonal MD1200 aqueous dispersion (10%)” manufactured by Toyobo Co., Ltd.) was applied with a wire bar # 5, and dried to form an anchor layer. (Image receiving layer) Styrene copolymerized acrylic emulsion (Nippon Shokubai Co., Ltd. “Acreset aqueous dispersion (10
%) ") Was applied using a wire bar # 5 and dried to form an image receiving layer.

(8) Adhesion of Surface Coating Layer A 2 mm pitch cross-cut surface was placed on the surface of the surface-treated plastic film on the side of the surface coating layer, and a 90 ° peeling test was performed using a cellotape (Nichiban, 25 mm width). The adhesion was evaluated based on the area ratio of the residual surface coating layer at the cross stitch.

(9) In-plane birefringence The surface-treated plastic film is cut into a size of 10 cm × 10 cm, and its weight W (g) is weighed. Then, the density ρ (g) when there is no cavity inside the film
/ Cm ³ ), the actual thickness T (cm) of the film irrespective of the void content is calculated by the following equation. T = W / (ρ × 100) Next, using a molecular orientation meter MOA-2001A (manufactured by Kanzaki Paper Co., Ltd.) and substituting the thickness T obtained above, the refractive index in the microwave region is set to the longitudinal main axis. The in-plane birefringence was determined by the following equation along the lateral main axis. In-plane birefringence = longitudinal principal axis refractive index-transverse principal axis refractive index The density ρ was calculated from the composition ratio of each component constituting the surface-treated plastic film and its density.

(10) Ink Adhesion The ink adhesion was evaluated according to the following method. Oxidation polymerization type ink is tetron screen (# 250 mesh) on the surface coating layer of surface treated plastic film
After printing, the sheet was left for 16 to 24 hours, then a 2 mm pitch cross-cut surface was inserted, and a 90 ° peeling test was performed using a cellophane tape (manufactured by Nichiban Co., Ltd., 25 mm width). The judgment is as follows. ○ Good (90% or more ink remaining or cleavage of plastic film) △ Somewhat bad (70% or more and less than 90% ink remaining)

Example 1 Water-dispersible copolymerized polyester resin (A) as a resin component
(Toyobo Co., Ltd. “Vironal MD1200”,
Sulfonic acid group-containing copolyester, molecular weight about 15,00
0), silica particles (B) whose surface has been inorganic-treated with a magnesium-based treating agent (average particle diameter 3.5 μm: manufactured by Fuji Silysia Chemical Ltd.), synthetic polymer-based wax agent (C) (Nippon Shokubai Co., Ltd.) First, silica particles (B) were mixed with water and isopropyl alcohol (weight ratio: 80/2) using a homogenizer using "CX-ST200", an acrylic wax, a molecular weight of 1,000,000 to 2,000,000.
After sufficiently dispersing in the mixed solution with (0), the resin (A) 5.0% by weight, the silica particles (B) 5.0% by weight and the synthetic polymer based on the total weight of the coating solution. The wax agent (C) was blended at 0.05% by weight and mixed well to prepare a coating solution. Apply this coating solution to wire bar # 5
Was applied on a polyester (polyethylene terephthalate) film having a thickness of 50 μm. The coating amount of the coating liquid was about 10 g (wet state) per 1 m ² of the plastic film.
/ M ² , a surface-treated plastic film having a surface coating layer was obtained.

The properties of the obtained surface-treated plastic film are as shown in Table 1. The printability of the film surface is good, the bleeding index of the water-based and alcohol-based inks is 1.0, and writing with an aqueous ballpoint pen is performed. There was no bleeding of time, and the writing feeling was good and extremely excellent.

[0065]

[Table 1]

Example 2 A coating liquid was prepared in the same manner as in Example 1 except that the silica particles (B) were subjected to a surface organic treatment by spray coating using a saturated hydrocarbon-based spray wax. Thereafter, similarly, a surface-treated plastic film was obtained.

Example 3 A surface-treated plastic film was obtained in the same manner as in Example 1 except that the polyester film containing fine voids produced by the following method was used as the plastic film.

(Preparation of Plastic Film) 80% by weight of polyethylene terephthalate resin having an intrinsic viscosity of 0.62
And general-purpose polystyrene (“T575 manufactured by Mitsui Toatsu Chemicals, Inc.
-57U ") 15% by weight and an average particle size of 0.35 µm anatase type titanium dioxide (" TA-3 "manufactured by Fuji Titanium Co., Ltd.)
00 ") 5% by weight as a raw material, and these are charged into a twin-screw extruder and uniformly mixed therewith.
It is melt-extruded at 0 ° C., solidified by cooling by electrostatically adhering to a cooling rotating roll, and has a thickness of about 1100 μm.
Was obtained. Next, the unstretched sheet is stretched 3.7 times in the machine direction at 80 ° C. by a roll stretching machine, and then subjected to a relaxation treatment so that the actual magnification becomes 3.2 times. After stretching 0 times, the film was further stretched 1.5 times at 220 ° C. with a tenter. Thereafter, the resultant was subjected to a heat treatment while relaxing at 235 ° C. by 4%, and then cooled to obtain a 100 μm-thick polyester film containing a large number of fine cavities inside.

Example 4 A surface-treated plastic film was obtained in the same manner as in Example 2 except that the polyester film containing fine voids produced in the same manner as in Example 3 was used as the plastic film.

Example 5 Resin (A) (Example 1)
10% by weight, surface inorganic treated silica particles (B) (same as in Example 1) 10% by weight, and synthetic high molecular wax agent (C) (same as in Example 1) 0.10% by weight
Were sufficiently mixed to prepare coating solutions.

On the other hand, 80% by weight of a polyethylene terephthalate resin having an intrinsic viscosity of 0.62, 15% by weight of polystyrene for general use (“T575-57U” manufactured by Mitsui Toatsu Chemicals, Inc.), and anatase type titanium dioxide having an average particle diameter of 0.35 μm. (TA-300 manufactured by Fuji Titanium Co., Ltd.) 5% by weight as a raw material, these are charged into a twin-screw extruder, mixed uniformly, and melt-extruded at 290 ° C. from a T-die.
The sheet was cooled and solidified by electrostatically adhering to a cooling rotating roll to obtain an unstretched sheet having a thickness of about 1100 μm. Next, the unstretched sheet is subjected to 8
After being stretched 3.7 times at 0 ° C., the film was relaxed so that the actual magnification became 3.2 times to obtain a uniaxially stretched film.

The coating solution prepared above was applied to the surface of the uniaxially stretched film using a wire bar # 14 to a thickness of 5 g /
m ² · dry, followed by transverse stretching by a tenter 3.0 times at 125 ° C. and 1.5 times at 220 ° C., followed by heat treatment at 235 ° C. while relaxing 4%. To obtain a surface-treated plastic film having a thickness of about 100 μm in which a number of fine cavities were formed inside the plastic film.

Example 6 A coating liquid was prepared in the same manner as in Example 5 except that the silica particles (B) were subjected to a surface organic treatment by spray coating using a saturated hydrocarbon-based spray wax. Thereafter, similarly, a surface-treated plastic film was obtained. The property evaluation results of the surface-treated plastic films obtained in Examples 2 to 6 are as described in Table 1, and good results almost similar to those of Example 1 were obtained.

Example 7 As a resin component, an organic solvent-soluble copolymerized polyester resin (A) (“Byron RV-20” manufactured by Toyobo Co., Ltd.)
0 ", molecular weight of about 20,000), and silica particles (B) having a surface inorganic treatment (magnesium treatment) (average particle diameter: 3.5 μm:
Fuji Silysia Chemical Industries Ltd.), synthetic polymer wax agent (C) (CX-ST10, manufactured by Nippon Shokubai Co., Ltd.)
0 ", acrylic wax, molecular weight 50,000-1,200,000
), First, using a homogenizer, convert the silica particles (B) into toluene and methyl ethyl ketone (weight ratio: 60%).
/ 40), the resin (A) is 5.0% by weight, the silica particles (B) is 5.0% by weight, and the synthetic polymer system is based on the total weight of the coating solution. The wax agent (C) was blended so as to be 0.05% by weight, and sufficiently mixed and dissolved in a solvent (toluene / methyl ethyl ketone = 60/40) to prepare a coating solution. Apply this coating solution to a wire bar #
5 was applied on a polyethylene terephthalate film having a thickness of 50 μm. After the coating, the coating was dried at 160 ° C. for about 60 seconds to obtain a surface-treated plastic film having a surface coating layer having a coating amount of about 1 g / m ² . The properties of the obtained surface-treated plastic film are as shown in Table 1. The printability of the film surface is good. The bleeding index of the aqueous and alcohol-based inks is 1.0. There was no writing comfort.

Example 8 A polyester film containing fine voids produced in the same manner as in Example 3 was used as a plastic film, and the resin component of Example 1 was replaced with a water-dispersible copolymerized polyester resin (A) (Toyobo Co., Ltd.). Co., Ltd. “Vylonal MD-
16 ") and a heat-reactive water-soluble urethane resin (B) having a blocked isocyanate group (" Elastron H-38 "manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) in terms of solid weight ratio (A) /
(B) A surface-treated plastic film was obtained in the same manner as in Example 1 except that the mixture was changed to 1/1. The results of evaluating the properties of the obtained surface-treated plastic film are as shown in Table 1, and the same good results as in Example 6 were obtained.

Comparative Example 1 In Example 1, the synthetic polymer wax agent (C) was used.
Was omitted, and a surface-treated plastic film was obtained in exactly the same manner as in Example 1 except that silica particles (B) were replaced with untreated surface silica particles.

The results of evaluating the properties of the obtained film are as shown in Table 1. The printability of the surface was good, but the bleeding index of the water-based and alcohol-based inks was insufficient. Although the writing comfort was good at the time of writing, the bleeding of the ink was remarkable and it was very unclear.

Comparative Example 2 The same procedure as in Example 2 was repeated except that the synthetic polymer wax agent (C) was used.
Was omitted, and a surface-treated plastic film was obtained in the same manner. The results of evaluating the properties of the obtained film are as shown in Table 1. The printability of the surface-treated film surface was good, but the bleeding index of the aqueous and alcohol-based inks was insufficient. In addition, although the writing comfort at the time of writing with an aqueous ballpoint pen was good, the bleeding index of the ink was high and insufficient.

Comparative Example 3 The same procedure as in Example 3 was carried out except that the synthetic polymer wax agent (C) was used.
A surface-treated plastic film was obtained in exactly the same manner as in Example 3 except that the use of was omitted. The properties of the obtained film are as shown in Table 1. The printability of the surface-treated film surface was good, but the bleeding index of the water-based and alcohol-based inks was insufficient, and the water-based ballpoint pen was used. The writing comfort during writing was good, but the ink bleeding index was high and insufficient.

Comparative Example 4 The procedure of Example 4 was repeated except that the synthetic high molecular wax agent (C) was used.
A surface-treated plastic film was obtained in exactly the same manner as in Example 4 except that the blending of was omitted. The results of evaluating the properties of the obtained film are as shown in Table 1. The printability of the surface was good, but the bleeding index of the water-based and alcohol-based inks was insufficient. The writing comfort was good, but the ink bleeding index was high and insufficient.

Comparative Example 5 A surface-treated plastic film was obtained in the same manner as in Example 1, except that the blending of the surface-inorganized silica particles was omitted. The results of evaluating the properties of the obtained film are as shown in Table 1, and the ink bleeding index of the film was less than 1.0, which caused repelling of the ink. Further, the printability of the film surface was poor, and writing with an aqueous ballpoint pen was impossible.

Examples 9 to 13 Surface-treated plastic films of Examples 1 and 3 to 6
Polyvinyl alcohol (Kuraray) on the surface coating layer of
"PVA117" manufactured by Co., Ltd.) 20 parts by weight and a block
Polyurethane Resin Having Isocyanate Group (Daiichi Kogyo
"Elastron H-38" manufactured by Nippon Seiyaku Co., Ltd.) 10 parts by weight, flat
20 parts by weight of spherical silica particles having an average particle diameter of 2.5 μm
Dry the ink receiving layer solution obtained by dissolving it in 230 parts by weight.
After 16g / m ^TwoApply with a wire bar so that
An ink jet recording medium was obtained. The ink jet recording medium
Design jet HP-650C (Hewlett-Pack
The map was printed using a card company. Thin lines are blurred
It became beautiful in color. Also, the ink receiving layer
Scotch tape (Nichiban, 25mm width)
Peeled off quickly, but the ink receiving layer did not peel off
Was.

[0083]

The surface-treated plastic film of the present invention has an ink bleeding index of 1.0 to 1.2 with respect to water-based and alcohol-based inks, has little ink bleeding when writing with an aqueous ballpoint pen, and has good writability and offset printing. Excellent in properties and extremely useful as synthetic paper. In addition, by using the surface-treated plastic film, an ink jet recording body capable of performing high-quality recording can be obtained.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuya Ito 2-1-1 Katata, Otsu City, Shiga Prefecture Inside the Film Technology Center of Toyo Spinning Co., Ltd. (72) Takashi Saito 2-1-1 Katata, Otsu City, Shiga Prefecture No. Toyo Spinning Co., Ltd. Film Technology Center (72) Inventor Shinji Sawasaki 2-1-1 Katata, Otsu-shi, Shiga Prefecture Toyo Spinning Co., Ltd. Film Technology Center (72) Inventor Yasushi Sasaki 2-1-1 Katata, Otsu-shi, Shiga Prefecture No. 1 Toyo Boseki Co., Ltd. Film Technology Center (56) References JP-A-63-170088 (JP, A) JP-A-6-134950 (JP, A) JP-A-6-316644 (JP, A) JP-A-5-287099 (JP, A) JP-A-3-96332 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J ^7/ 04-7/06 C08J 5/18 B32B 27/36

Claims (1)

(57) [Claims] On at least one surface according to claim 1] polyester film, a surface-treated plastic film of the surface coating layer formed, a polyester-based film, polyester and the Poriesu
Containing at least one thermoplastic resin that is incompatible with
At least it is stretched in the uniaxial direction
The surface-treated plastic film has an apparent specific gravity of 0.
8 to 1.3, and the bleeding index for water-based and alcohol-based inks on the surface coating layer side is 1.0 to 1.0, respectively.
Surface-treated plastic film of -1.2.