JPH0948865A - Surface-treated plastic film and ink-jet recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface-treated plastic film which is very useful as a synthetic paper because it is excellent in writing properties with reduced ink bleeding caused by an aqueous ball point pen and in the offset print quality. SOLUTION: The surface plastic film has a surface-coating layer at least on one surface and the bleeding indexes to aqueous and alcoholic ink are 1.0-1.2 on the surface-coating layer side, respectively. The ink-jet recording medium has the ink-receiving layer formed on the surface-coating layer of said surface- treated plastic film.

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, etc. The present invention relates to a surface-treated plastic film which is excellent in selective absorption and diffusion prevention for alcohol-based inks and has dramatically improved writability and printability. Further, the present invention relates to an ink jet recording material which uses the surface-treated plastic film and is capable of high-quality image printing.

[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 become widely used in the fields of labels, maps, posters, business cards, delivery slips, recording paper for various printers, and the like.

[0003]

However, since the ordinary plastic film has a smooth surface and hardly absorbs water-based and alcohol-based inks, a pencil,
There is a problem that the writing performance is poor with a ballpoint pen, water-based pen, or the like. Further, it has been pointed out that since the water-based and alcohol-based inks are difficult to be absorbed, the drying property of the inks is poor, and furthermore, the inks are bleeding and become unreadable.

The object of the present invention is to improve the absorbability of water-based and alcohol-based inks in the surface layer portion of a plastic film, enhance the writability with a water-based pen or the like, and the acceptability of stamp inks, red ink, etc. It is an object of the present invention to provide a surface-treated plastic film that can be used as a synthetic paper in place of natural paper such as labels, delivery slips, recording paper for various printers, and information recording paper without any trouble. Another object of the present invention is to provide an ink jet recording material using the surface-treated plastic film, which enables 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 having a surface-coating layer formed on at least one surface of a plastic film, wherein the surface-coating layer side of the surface-treated plastic film has a bleeding index of 1.0 to 1. 2. A surface-treated plastic film that is 2. The surface-treated plastic film according to claim 1, wherein the surface coating layer contains 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 as essential components. The surface-treated plastic film as described 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. The surface-treated plastic film according to any one of 1 to 3, wherein the plastic film is a polyester film. The polyester film contains polyester and one or more thermoplastic resins incompatible with the polyester,
The surface-treated plastic film according to claim 1, wherein the surface-treated plastic film has fine cavities inside by being stretched in at least one axial direction, and the apparent specific gravity of the surface-treated plastic film is 0.8 to 1.3. The surface-treated plastic film according to any one of 1 to 4, which has a light transmittance of 30% or less and an in-plane birefringence of -0.02 or more and +0.04 or less. An ink jet recording material comprising an ink receiving layer provided on the surface coating layer of the surface-treated plastic film as described in any one of 1 to 3 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 a bleeding index for the water-based and alcohol-based inks on the surface coating layer side of the surface-treated plastic film. Is characterized in that each is 1.0 to 1.2. If the ink bleeding index is less than 1.0, for example, in the case of a seal stamp ink, the seal stamp ink may be repelled, resulting in thinning or breakage, which makes it difficult to read the seal impression. , The seal ink bleeds, making it difficult to read, and it no longer serves as a seal. The same applies to printing inks and writing inks.

The water-based ink used in the present invention is "Bandow Stamp exclusive replenishment ink: vermilion" manufactured by Bando Co., Ltd., water / polymer glycol / alcohol / dye = 40.
/ 30/20/10 (wt%). The alcohol-based ink is "refilling ink for Shachihata stamp: S-1 black" manufactured by Shachihata Industry Co., Ltd., and alcohol / water / dye / surfactant / others = 50-60 / 2.
It consists of 0 to 30/5 to 10/1 to 3/1 to 3 (wt%).

In the present invention, the ink bleeding index is
The value measured by the following method. That is, a sample film is set horizontally on a sample stand of a stereomicroscope equipped with a camera so that the surface coating layer side faces upward, and 0.6 μl of water-based or alcohol-based ink is placed on the upper surface of the sample film with a microsyringe. Area of ink adhesion image immediately after dropping (S ₁ ) and area of ink adhesion image after 30 minutes (S ₂ )
From the pictures taken under the same conditions. The S thus obtained for each of the water-based and alcohol-based inks
_{Using 1} and S ₂ , the ink bleeding index for each of the water-based ink and the alcohol-based ink is calculated by the following formula. Ink spreading index = S ₂ / S ₁

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

The inorganic particles used in the present invention are not particularly limited, and examples thereof include silica, calcium carbonate, calcium sulfate, barium sulfate, magnesium hydroxide, aluminum hydroxide, talc, zeolite, alumina, titanium dioxide, zinc oxide and the like. Particles may be mentioned. Among these, silica particles are particularly preferable. The particle diameter of the inorganic particles is preferably in the range of 0.5 to 10 μm, more preferably 1.0 to 5.0 μm. The inorganic particles may be used alone or in combination of two or more. Further, it is of course possible to use two or more kinds of particles having different particle sizes together.

In the present invention, the term "organic surface treatment and / or inorganic surface treatment" applied to the surface of the inorganic particles means that the particles are partially hydrophobized to reduce the secondary cohesiveness of the particles and disperse the particles. It is carried out in order to improve the property and control the diffusion of the water-based ink and the alcohol-based ink.

Examples of the organic surface treatment method include silylation with a coupling agent (eg, vinyltris (β-methoxyethoxy) silane, 3-aminopropyltriethoxysilane, etc.) and higher fatty acids (eg, stearic acid, palmitic acid, etc.). 2) esterification, and treatment with a saturated hydrocarbon or resin (eg, paraffin wax, stearic acid amide, silicone resin, fluororesin). The inorganic surface treatment method may, for example, be a surface reaction with an inorganic coupling agent, a metal alkoxide or a metal ion, or a method of ion exchange. Of these, the method using a magnesium-based treating agent is particularly preferable.

Specific examples of 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 of immersing the inorganic particles in a liquid of the surface treatment agent. And a method of adhering 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 well-known polymer wax that can be dispersed or emulsified in water, and examples thereof include polyethylene-based, polypropylene-based, acrylic-based, and fatty acid-based waxes. Among these polymer waxes, particularly preferable are polymer waxes which have a high affinity for a solvent, are hard to stick, and have excellent thermal dispersion stability, and particularly polyethylene wax, acrylic wax and the like. Is most suitable as a bleeding index control agent. Here, polyethylene wax, polypropylene wax, etc. have a number average molecular weight of 1,000 to 20,000, preferably 1,000 to 1.
0000. The number average molecular weight of the acrylic wax is 5,000 to 5,000,000, preferably 10,000 to 3,000,000, and more preferably 1,000.
The range is from 00 to 2,000,000.

An aqueous resin or an organic solvent-soluble resin is used as another essential component constituting the surface coating layer.
The water-based resin is a water-soluble and / or water-dispersible resin, and is, for example, polyvinyl alcohol, ion-modified polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyurethane, blocked isocyanate-containing urethane oligomer, starch, gelatin, casein, carboxymethylcellulose. Polymer materials such as hydroxyethyl cellulose, copolyester, polyacrylic acid, acrylic acid-based copolymer, and polyvinyl acetate. The organic solvent-soluble resin is a resin that is soluble in toluene, methyl ethyl ketone, or ethyl acetate alone or in a mixed solvent, and examples thereof include copolyesters, polyurethanes, acrylic copolymers, and styrene-butadiene copolymers. To be These may be used alone or in combination of two or more if necessary. Above all, it is preferable to use an aqueous resin in terms 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 inorganic particles to 100 parts of the aqueous resin or the organic solvent-soluble resin in terms of solid content. , And more preferably 65
It is in the range of up to 150 parts. When the compounding ratio of the inorganic particles is less than 25 parts by weight, the ink absorbency tends to decrease, while when it exceeds 250 parts by weight, the scratch resistance of the surface coating layer tends to decrease.

The mixing ratio of the polymer wax to the water-soluble resin or the organic solvent-soluble resin is 0.1 to 100 parts of the water-based resin or the organic solvent-soluble resin in terms of solid content. The range of 5.0 parts is preferable,
The range is more preferably 0.5 to 1.5 parts. If the amount of the polymer wax is less than 0.1 parts by weight, the ink bleeding tends to be large, while if it exceeds 5.0 parts by weight, the ink absorbency tends to decrease.

The surface coating layer containing the above-mentioned three components as essential components has improved additional functions (for example, scratch resistance, antistatic property, water resistance, etc.) as the outermost layer of the surface-treated plastic film. Therefore, it is also effective to include various additives such as a cross-linking agent (melamine-based, isocyanate-based, etc.), an antistatic agent, etc., if necessary.
Among the antistatic agents, particularly organic low-molecular antistatic agents tend to promote the diffusibility of the ink and increase the bleeding, so that, for example, inorganic compounds such as Zn-Sn compounds, titanic acid compounds, and phosphorus compounds are used. 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. 0.
The 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, polymethylmethacrylate, polyvinyl chloride, polyvinylidene chloride and polyvinylidene fluoride.
Examples thereof include polymer films made of one kind or two or more kinds. Of these, a polyester film is particularly preferable. 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 is an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid or an ester thereof, and ethylene glycol, diethylene glycol, 1,4-butanediol or neo. Examples include polyesters produced by polycondensing glycols such as pentyl glycol. The polyester is a method of directly reacting an aromatic dicarboxylic acid and a glycol, a method of transesterifying an alkyl ester of an aromatic dicarboxylic acid and a glycol and then polycondensing, or a diglycol ester of an aromatic dicarboxylic acid. It can also be produced by a method such as polycondensation.

Specific examples of the above-mentioned 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, especially ethylene terephthalate units, butylene terephthalate units or ethylene-2,6-naphthalate units account for 70 mol% or more of the total polyester,
Preferably 80 mol% or more, more preferably 90 mol%
The above polyesters are preferable. By selectively using such polyester as a plastic film material, it is possible to obtain a surface-treated plastic film that is much more excellent in terms of dimensional stability and heat resistance.

Further, as a film material, a material in which one or more thermoplastic resins incompatible with the polyester is blended together with the above polyester is used, and after being formed into a film, at least by a method described below. A uniaxial stretching treatment is performed, and preferably, biaxial stretching is performed in the longitudinal and transverse directions to form a large number of fine cavities inside the film,
The apparent specific gravity of 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 which is incompatible with polyester is blended as a void-developing agent for forming fine voids in the polyester film to enhance flexibility, lightness and drawing properties. As long as it is incompatible with polyester, it can be used without particular limitation. 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.

The thermoplastic resin is, for example, a polystyrene resin (eg, 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 these, polystyrene resin or polyolefin resin such as polymethylpentene or polypropylene is particularly preferable.

The amount of the thermoplastic resin blended with the polyester varies depending on the target amount of voids formed in the plastic film and the stretching conditions, but is preferably in the range of 3 to 40% by weight with respect to the entire plastic film. ,
Particularly, 5 to 15% by weight is preferable. If it is less than 3% by weight, there is a limit to increase the amount of cavities formed, and it tends to be difficult to obtain the flexibility, lightness, or drawability imparted to the plastic film by the cavity formation. On the other hand, if it exceeds 40% by weight, the stretchability tends to be lowered, and the heat resistance, strength, and stiffness of the plastic film tend to be impaired. The above thermoplastic resins may be used alone or in combination of two or more.

Further, in the plastic film used in the present invention, inorganic particles or organic particles may be added, 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 monolayer film or a composite film having two or more layers, depending on the application. The method for producing the composite film is not particularly limited, but from the viewpoint of productivity and the like, the raw materials for the respective layers are extruded from different extruders and introduced into one die to obtain an unstretched film, Most preferred is lamination by a so-called co-extrusion method in which at least uniaxial orientation is performed.

The surface-treated plastic film of the present invention comprises:
A surface coating layer containing, as essential components, inorganic particles that have been subjected to the above-described organic surface treatment and / or inorganic surface treatment, 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 of 0.8 to 1.3, preferably 1.0 to 1.25, as described above. More preferably 1.05-1.
The range is 25. When the apparent specific gravity is less than 0.8, the void content becomes excessively large, the strength of the surface-treated plastic film tends to be insufficient, and cracks or wrinkles are likely to occur on the surface of the surface-treated plastic film. On the contrary, when the apparent specific gravity exceeds 1.3, the void content becomes insufficient,
The cushioning property, flexibility, and drawing property tend to deteriorate.

The apparent specific gravity can be adjusted by the kind 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. Surface treated plastic film 5.00c
The thickness was accurately cut into a square of m × 5.00 cm, the thickness was measured at 50 points to give an average thickness of tμm, and the weight was measured up 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 comprising a plastic film containing or not containing fine voids has a light transmittance of 30% or less and an in-plane birefringence of -0.02 or more and +0.04 or less. Those are preferable.

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, still more preferably 15% or less, in order to enhance its suitability as a 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 the fine void content and the amount of added particles.

Here, the light transmittance is JIS-K671.
In accordance with the Poic 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, if the in-plane birefringence exceeds +0.04, on the contrary, the film is likely to be longitudinally torn, and the film is likely to be broken during slitting or to be easily torn in the longitudinal direction when the film is cut. There is. Further, the in-plane birefringence is −0.
When it is less than 02 or more than +0.04, wrinkles and curls are likely to occur when printing with a printer or the like. Here, the in-plane birefringence being + (or −) means that the history of longitudinal stretching remains larger (or smaller) than the history of transverse stretching, which is a so-called bowing phenomenon during transverse stretching. It may be accompanied by some distortion of the principal axis of the refractive index.

Here, the in-plane birefringence was measured as follows. Surface treated plastic film 10 cm ×
Cut into a size of 10 cm, and weigh the weight W (g). Then, from the density ρ (g / cm ³ ) when there are no voids inside the film, the actual thickness T (cm) of the film irrelevant to the void content is calculated by the following formula. 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−horizontal 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.

In the first longitudinal stretching step, longitudinal stretching is carried out in the running direction of the film while being appropriately heated between two or a large number of 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. Further, if the longitudinal magnification exceeds 5 times, it becomes difficult to sufficiently perform the subsequent relaxation treatment, and it becomes substantially difficult to set the in-plane birefringence of the surface-treated plastic film to 0.04 or less.

After the above-mentioned longitudinal stretching, a relaxation treatment of 3% or more, preferably 5% or more, is performed in the longitudinal direction. 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 relaxation to 2.8 to 3.5. If the relaxation rate is set to 3% or more, the in-plane birefringence is -0.02 to +0.04.
It becomes possible to industrially stably produce the surface-treated plastic film. On the other hand, if the relaxation rate is less than 3%, the lateral stretchability in the next step is significantly deteriorated, and it tends to be difficult to form a film having in-plane birefringence of -0.02 to +0.04. . A surface-treated plastic film having an apparent specific gravity of more than 1.3 (using a film having a small content of fine voids) can give isotropic property without performing such a relaxation treatment,
As mentioned above, in order to produce a film containing fine voids which is lightweight, flexible, and has excellent drawability, it is preferable to perform the above relaxation treatment.

Further, as described above, the preferred longitudinal stretching ratio after the longitudinal relaxation treatment is 2.8 to 3.5. If the longitudinal stretching ratio is less than 2.8, the relaxation is likely to be poor and uneven. ,
It tends to be difficult to obtain a homogeneous film, and moreover, 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, stretching failure 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 for carrying out the relaxation treatment, after the longitudinally stretched film is once cooled, it is reheated to about 80 to 150 ° C. in a heating device such as an oven, or immediately after longitudinal stretching without cooling. Between the driving roll group and the free roll group heated to about 60 to 100 ° C., and a method of performing an appropriate combination of 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 after the relaxation treatment, the film is transversely stretched at a draw ratio of at least the longitudinal stretching ratio and then heat-treated. 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 −
In order to make it 0.02 or more, (longitudinal stretching ratio after relaxation treatment +
It is preferable to suppress it to 1.0) times or less.

The biaxially stretched film thus obtained is preferably subjected to heat treatment, if necessary. 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 writability and printability, a coating method is used. Generally, specifically, gravure coating method, kiss coating method, dip method, spray coating method, curtain coating method, air knife coating method, blade coating method,
A reverse roll coat method and the like can be mentioned. As the application timing, any method such as a method of applying before stretching the plastic film, a method of applying after the longitudinal stretching, a method of applying to the film after the orientation treatment, and the like may be adopted. In order to enhance the adhesion between the plastic film and the surface coating layer, the most preferable one is to apply the coating solution to at least one surface of the uniaxially stretched plastic film by the above coating method, and then to form a right angle with the further uniaxial stretching direction. It is an in-line coat that stretches in the direction.

The surface-treated plastic film of the present invention thus obtained has less bleeding of water-based and alcohol-based inks, is excellent in drawing properties and printability, and is superior to conventional plastic films which have been put into practical use as synthetic paper. It has excellent properties in terms of writing ability, receptivity of stamp ink and red ink for stamps, and excellent transportability in various printers. Furthermore, solvent-based inks, water-based inks used in various printing, and It has excellent adhesion to various inks such as UV curable inks and improved toner adhesion to bar code labels. It has excellent performance as various labels, bar code labels, delivery slips, various printer papers, information recording papers, etc. Demonstrate.

A surface-treated plastic film in which a surface coating layer is formed on at least one side of a plastic film, and the bleeding index for the water-based and alcohol-based inks on the surface coating layer side of the surface-treated plastic film is 1.0, respectively. A surface-treated plastic film of 1.2 to 1.2 is used, and the surface coating layer is preferably an inorganic particle having an organic surface treatment and / or an inorganic surface treatment, a polymer wax, an aqueous resin or an organic solvent. The inkjet recording material of the present invention can be obtained using a surface-treated plastic film containing a molten resin as an essential component. That is, the inkjet recording material 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 inkjet recording material with less ink bleeding,
Further, the adhesive strength of the ink receiving layer to the surface-treated plastic film becomes good.

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, polyvinylpyrrolidone, polyacrylamide, polyester, phenol 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, and the like, which increases the degree of curing of the ink receiving layer and improves the water resistance. 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.

Further, the ink receiving layer is silica, kaolinite, talc, calcium carbonate, zeolite, alumina, barium sulfate, carbon black, zinc oxide, titanium oxide, organic white pigment, benzoguanamine, crosslinked polystyrene, crosslinked acrylic resin, water. Particles such as aluminum oxide may be blended.

As a method of forming the ink receiving layer,
Gravure coat system, kiss coat system, dip system,
A commonly used method such as a spray coating method, a curtain coating method, an air knife coating method, a blade coating method or 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 film material The resin used as the 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 ("Bandow Stamp exclusive replenishment ink: vermilion", sold as of January 1, 1995) or alcohol-based ink (Shachihata Industrial Co., Ltd. "Shachihata Stamp" Replenishment ink: S-1 black ”, 1995 1
(Sold as of January 1) is weighed with a microsyringe to 0.6 μm, and the ink is weighed on the surface (surface coating layer side) of the sample film preset on the sample stand of the stereo microscope (Nikon UFX) equipped with a camera. Drop it. The ink adhesion image area immediately after dropping (S ₁ ) and the ink adhesion image area after 30 minutes (S ₂ ) were obtained 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 area was calculated by the following formula, which was taken 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 machine (Ricoh Auto Printer AP37
00, manufactured by Ricoh Co., Ltd. and oxidation polymerization type ink (GRAF-G
Each sample film surface (surface coating layer side) was actually printed using black ink (manufactured by Dainippon Ink and Chemicals, Inc.), and the inking property of the solid portion was visually evaluated. The state in which the ink was uniformly transferred with no spots was marked with ◯, and the state in which there were spots with transferred ink and the density was low was marked with x.

(4) Writability with a water-based ballpoint pen After writing on the surface of the sample with a water-based ballpoint pen (Mitsubishi Uniball / VB106Z, manufactured by Mitsubishi Pencil Co., Ltd.), the bleeding state of the written characters after 16 hours was visually evaluated. . The one in which the written character could be identified was marked as ○, and the one in which it could not be distinguished was marked as ×. The writing comfort during writing was evaluated by writing straight and curved lines. Here, a mark that does not get caught and that can be written smoothly is marked with ◯.

(5) Apparent Specific Gravity Surface treated plastic film is 5.00 cm x 5.0
The thickness was accurately cut into a square of 0 cm, the thickness was measured at 50 points, the average thickness was set to t μm, and the weight was measured up to 0.1 mg to be wg, which was calculated by the following formula. Apparent specific gravity = w × 10000 / (5 × 5 × t)

(6) Light transmittance According to JIS-K6714, the Poick integrating sphere type H.
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, the higher the concealing property.

(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 on the surface coating layer. S
CAN CH-5504 (manufactured by Seiko Electronics Co., Ltd.)
I actually output the image from the video. If curl was confirmed in the printed matter output at this time, it was evaluated as ×, and if not, it was evaluated as ○. (Anchor layer) A sulfonic acid group-containing copolyester (“BYRONAL MD1200 water 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 copolymer acrylic emulsion (Nippon Shokubai Co., Ltd. "Akurisetu water dispersion (10
%) ”) Was applied with a wire bar # 5 and dried to form an image receiving layer.

(8) Adhesion of surface coating layer A cross-cut surface having a pitch of 2 mm was put on the surface of the surface-treated plastic film on the surface coating layer side, and a 90 ° peeling test was carried out with cellophane tape (Nichiban, 25 mm width). Adhesion was evaluated by the area ratio of the residual surface coating layer in the cross pattern.

(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 irrelevant to the void content is calculated by the following formula. 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−horizontal 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 based on the following method. Oxidized polymerization type ink on the surface coating layer of surface treated plastic film, Tetoron screen (# 250 mesh)
After printing for 16 to 24 hours, a cross-cut surface with a pitch of 2 mm was put in, and a 90 ° peeling test with cellophane tape (25 mm width, manufactured by Nichiban Co., Ltd.) was performed, and the same evaluation was performed. 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 copolyester resin (A) as a resin component
(Toyobo Co., Ltd. “Baylonal MD1200”,
Copolyester containing sulfonic acid group, molecular weight about 15,00
0), silica particles (B) surface-inorganized with a magnesium-based treating agent (average particle size 3.5 μm: manufactured by Fuji Silysia Chemical Ltd.), synthetic polymer wax agent (C) (Nippon Shokubai Co., Ltd.) Manufactured by "CX-ST200", acrylic wax, molecular weight 1,000,000 to 2,000,000) is used. First, silica particles (B) are mixed with water and isopropyl alcohol (weight ratio 80/2 by a homogenizer).
After being sufficiently dispersed in a mixed solution with 0), the resin (A) is 5.0% by weight, the silica particles (B) is 5.0% by weight, and the synthetic polymer system is a ratio based on the total weight of the coating solution. A wax agent (C) was blended so as to be 0.05% by weight and mixed sufficiently to prepare a coating solution. Apply this coating solution to wire bar # 5
Was applied onto a polyester (polyethylene terephthalate) film having a thickness of 50 μm. The coating amount of the coating liquid is about 10 g per 1 m ² of the plastic film (wet state), and after coating, it is dried at 160 ° C. for about 60 seconds to 1 g.
A surface-treated plastic film having a surface coating layer of / m ² was obtained.

The characteristics 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 water-based and alcohol-based inks is 1.0, and the writing with an aqueous ballpoint pen is performed. There was no bleeding with time, the writing comfort was good and it was extremely excellent.

[0065]

[Table 1]

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

Example 3 A surface-treated plastic film was obtained in the same manner as in Example 1 except that the fine void-containing polyester film produced by the following production 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 [mu] m anatase type titanium dioxide (" TA-3 "manufactured by Fuji Titanium Co., Ltd.
00 ") 5% by weight as raw materials, and while feeding these into a twin-screw extruder and uniformly mixing, 29
Melt extruded at 0 ° C., cooled and solidified by electrostatically adhering to a cooling rotary roll, and a thickness of about 1100 μm.
To obtain an unstretched sheet. Next, this unstretched sheet was stretched 3.7 times in the machine direction at 80 ° C. by a roll stretching machine, then subjected to a relaxation treatment so that the actual magnification was 3.2 times, and subsequently, it was stretched at 125 ° C. by a tenter at 3. After stretching 0 times horizontally, it was further stretched 1.5 times horizontally at 220 ° C. with a tenter. Then, the film was heat-treated while relaxing at 4% at 235 ° C. and then cooled to obtain a 100 μm-thick polyester film containing a large number of fine voids inside.

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

Example 5 In the same manner as in Example 1, the resin (A) (Example 1) was used.
Same as the above), 10% by weight of surface-treated inorganic silica particles (B) (same as in Example 1) and 0.10% by weight of synthetic polymer wax agent (C) (same as in Example 1).
Was thoroughly mixed to prepare a coating solution.

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

The surface of this uniaxially stretched film was coated with the coating solution prepared above using a wire bar # 14 to give a thickness of 5 g /
m ² · dry, and then transversely stretched by a tenter at 125 ° C. by 3.0 times and 220 ° C. by 1.5 times, and then heat-treated at 235 ° C. while being relaxed by 4%. After cooling, a surface-treated plastic film having a thickness of about 100 μm in which a large number of fine cavities were formed inside the plastic film was obtained.

Example 6 A coating solution was prepared in the same manner as in Example 5, except that the silica particles (B) in Example 5 were replaced with those subjected to surface organic treatment by spray coating using a saturated hydrocarbon wax type wax. Then, a surface-treated plastic film was obtained in the same manner. The results of evaluating the characteristics of the surface-treated plastic films obtained in Examples 2 to 6 are as shown in Table 1, and the same good results as in Example 1 were obtained.

Example 7 Copolymerized polyester resin (A) soluble in an organic solvent as a resin component (manufactured by Toyobo Co., Ltd., “Byron RV-20”).
0 ", molecular weight of about 20,000), surface inorganic treated (magnesium treated) silica particles (B) (average particle diameter 3.5 μm:
Fuji Silysia Chemical Industries Ltd.), synthetic polymer wax agent (C) (Nippon Shokubai Co., Ltd. “CX-ST10”
0 ”, acrylic wax, molecular weight 50,000-1,200,000
) Is used, and silica particles (B) are first mixed with toluene and methyl ethyl ketone (weight ratio: 60 by using a homogenizer).
/ 40), after being sufficiently dispersed in a mixed liquid, the resin (A) is 5.0% by weight, the silica particles (B) is 5.0% by weight, and the synthetic polymer system is in a proportion of the total weight of the coating liquid. The wax agent (C) was mixed in an amount of 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 the wire bar #
5 was applied onto a polyethylene terephthalate film having a thickness of 50 μm. After coating, it was dried at 160 ° C. for about 60 seconds to obtain a surface-treated plastic film having a surface coating layer with 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 water-based and alcohol-based inks is 1.0, and the bleeding during writing with an aqueous ballpoint pen is Moreover, the writing comfort was good.

Example 8 A polyester film containing fine voids produced by the same method as in Example 3 was used as a plastic film, and the resin component of Example 1 was used as a water-dispersible copolyester resin (A) (Toyobo Co., Ltd.). Co., Ltd. "Baironard MD-
16 ") and a heat-reactive water-soluble urethane resin (B) having a block type isocyanate group (" Elastron H-38 "manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) in terms of solid content weight ratio (A) /
A surface-treated plastic film was obtained in the same manner as in Example 1 except that (B) = 1/1 was mixed. The evaluation results of the properties of the obtained surface-treated plastic film are as shown in Table 1, and almost 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 surface-untreated silica particles were used instead of the silica particles (B).

The evaluation results of the characteristics 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, and the water-based ballpoint pen was used. The writing comfort was good, but the ink bleeding was remarkable and it became very unclear.

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

Comparative Example 3 In Example 3, 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, and 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 The writing comfort was good at the time of writing, but the ink bleeding index was high and was inadequate.

Comparative Example 4 In Example 4, the synthetic polymer wax agent (C) was used.
A surface-treated plastic film was obtained in exactly the same manner as in Example 4 except that the compounding was omitted. The results of evaluation of the properties of the obtained film are 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, and when writing with a water-based ballpoint pen. The writing comfort was good, but the ink bleeding index was high and it was insufficient.

Comparative Example 5 A surface-treated plastic film was obtained in the same manner as in Example 1 except that the compounding of the surface-inorganic silica particles was omitted. The evaluation results of 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, and the ink was repelled. In addition, 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
On top of the surface coating layer of polyvinyl alcohol (Kuraray
"PVA117" manufactured by Co., Ltd.) 20 parts by weight and block
-Type polyurethane resin with isocyanate groups
"Elastron H-38" manufactured by Kyo Pharmaceutical Co., Ltd.) 10 parts by weight, flat
20 parts by weight of spherical silica particles having a uniform particle diameter of 2.5 μm are mixed with water.
The ink receiving layer solution obtained by dissolving in 230 parts by weight is dried.
After 16g / m ²Apply with a wire bar so that
An inkjet recording material was obtained. The inkjet recording body
Design Jet HP-650C (Hewlett-Packard
A map was printed using a card company). Fine lines are blurred
It was beautiful in color. Also, the ink receiving layer
Attach cellophane tape (Nichiban, 25 mm width) to
And 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 for water-based and alcohol-based inks, has little ink bleeding when writing with an aqueous ballpoint pen, and has writability and offset printing. It has excellent properties and is extremely useful as a synthetic paper. Further, by using the surface-treated plastic film, an ink jet recording material capable of high quality recording can be obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08L 91/00 LSG C08L 91/00 LSG 101/00 LSY 101/00 LSY (72) Inventor Katsuya Ito 2-1-1 Katata, Otsu, Shiga Prefecture, Toyobo Co., Ltd., Film Technology Center (72) Inventor Takashi Nishito 2-1-1, Katata, Otsu, Shiga Prefecture, Toyobo Co., Ltd. (72) Inventor Shinji Sawasaki 1-1-1, Katata, Otsu-shi, Shiga Toyobo Co., Ltd. Film Technology Center (72) Inventor Yasushi Sasaki 2-1-1 Katata, Otsu-shi, Shiga Toyobo Co., Ltd. Film Technology Center

Claims (7)

[Claims] 1. A surface-treated plastic film having a surface coating layer formed on at least one side of a plastic film, wherein the surface coating layer side of the surface-treated plastic film has a bleeding index for water-based and alcohol-based inks, respectively. A surface-treated plastic film of 0 to 1.2. 2. 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 described in 1. 3. The surface-treated plastic according to claim 1, wherein the surface coating layer contains inorganic particles that have been subjected to an organic surface treatment and / or an inorganic surface treatment, a polymer wax, and an aqueous resin as essential components. the film. 4. The surface-treated plastic film according to claim 1, wherein the plastic film is a polyester film. 5. A polyester film comprising a polyester and a thermoplastic resin incompatible with the polyester.
The surface-treated plastic according to claim 4, wherein the surface-treated plastic film has an apparent specific gravity of 0.8 to 1.3, which comprises at least one kind of particles and has fine voids inside by being stretched in at least one axial direction. the film. 6. The surface-treated plastic film according to claim 1, which has a light transmittance of 30% or less and an in-plane birefringence of −0.02 or more and +0.04 or less. 7. An ink jet recording material comprising an ink receiving layer provided on the surface coating layer of the surface-treated plastic film according to claim 1.