JPH07304244A - Recording sheet - Google Patents

Abstract

PURPOSE:To improve the heat resistance, water resistance, setting property, and drying property of an ink by using a polymeric binder made of a urethane resin and a cationic polymer as principal components in a recording sheet which has a receiving layer containing a polymeric binder and porous particles at least on one side thereof. CONSTITUTION:In a recording sheet on which ordinary offset printing can be made wherein at least one side of a base material has a receiving layer containing a polymeric binder and porous particles whose oil absorption is 200 to 400ml/100g, the polymeric binder is prepared by using a urethane resin and a cationic polymer as principal components. The urethane resin is mainly a product of the reaction of polypropylene glycol and isophorone diisocyanate. As the base material, a polyester film, especially a transparent polyester film with an optical density of 0.20 to 0.50 or a white polyester film with an apparent specific gravity of 0.4 to 1.3 and a whiteness of 50% or more, is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet capable of general offset printing. More specifically, it relates to a recording sheet having excellent heat resistance, water resistance, ink setting property, ink drying property, blocking resistance, antistatic property, and transportability during printing.

[0002]

2. Description of the Related Art In various printing sheets centering on offset printing, a paper support has been dominant in the past, but in recent years, a plastic film has begun to be used as a support.

However, since the surface of a plastic film is generally poor in adhesiveness, it has been actively practiced to form an ink receiving layer having an excellent ink affinity when performing various printing processes on the surface. As such a printing sheet, for example, one disclosed in Japanese Patent Laid-Open Publication No. Hei 1-163093 is known.

In recent years, an electric decoration sheet, which is provided with a light source on the back side of a recording sheet and emits the light source at night to display on the front side by transmitted light, is becoming popular as a display sheet.

Conventionally, as a base material for such a sheet for electrical decoration, since moderate light transmittance and haze are required, a resin having high transparency such as an acrylic resin, a vinyl chloride resin, or a polycarbonate is mainly used. It is known that a pigment or an inorganic filler is added to.

Further, as in JP-A-1-186371, a transparent image fixing layer containing a resin component as a main component is provided on one surface of a transparent plastic film, and an opacifying layer is provided on the other surface, or an opacifying layer is provided. It is known that a transparent image fixing layer mainly containing a resin component is provided on at least one surface of a plastic film.

[0007]

However, since such a printing sheet is inferior in blocking resistance and antistatic property, it has a problem in transportability during offset printing, and when it is subjected to general oil-based offset printing. The ink setting property is poor. Further, when the printed matter is left in a stacked state in the offset printing process, there is a problem that set-off of ink occurs.

Further, when the above-mentioned acrylic resin or vinyl chloride resin is used as the base material of the sheet for electrical decoration, there is a problem in impact resistance and heat resistance, and polycarbonate having high impact resistance is expensive. .

Further, in the sheet for electrical decoration as disclosed in JP-A-1-186371, when a general oxidation polymerization type oil-based offset ink is used in the step of printing on the sheet surface, sufficient ink setting property, The ink dryness was not obtained.

According to the present invention, there is no occurrence of set-off of ink during a printing process, and ink transferability, ink setting property, ink drying property, ink adhesive property, blocking resistance, antistatic property,
It is an object of the present invention to provide a recording sheet which is excellent in transportability during printing and is also excellent in print quality such as sharpness and print density gradation.

[0011]

In order to achieve the above object, the present invention comprises a polymer binder and porous particles having an oil absorption of 200 to 400 ml / 100 g on at least one side of a substrate. In a recording sheet provided with a receiving layer,
The gist of the recording sheet is characterized in that the polymer binder contains a urethane resin and a cationic polymer as main components.

As the base material in the present invention, paper (fine paper), coated paper, Japanese paper, non-woven fabric or plastic film can be used, and among them, plastic film is preferable.

As the plastic film, polyester, polyolefin, polyamide, polyesteramide, polyether, polyimide, polyamideimide, polystyrene, polycarbonate, poly-P-phenylene sulfide, polyether ester, polyvinyl chloride,
Poly (meth) acrylic acid ester and the like are preferable. Furthermore, these copolymers, blends, and further crosslinked products can be used.

Among the above-mentioned substrates, polyesters such as polyethylene terephthalate, polyethylene 2,6-naphthalate, polyethylene α, β-bis (2-chlorophenoxy) ethane 4,4′-dicarboxylate, polybutylene terephthalate and the like are available. Considering mechanical properties, workability, quality, economy, etc., polyethylene terephthalate, polyethylene 2,
6-naphthalate is preferred.

The polyester used in the present invention is a well-known one, specifically, for example, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, bis-α, β (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid. Polycondensation of at least one bifunctional carboxylic acid such as acid, adipic acid and sebacic acid with at least one glycol such as ethylene glycol, triethylene glycol, tetramethylene glycol, hexamethylene glycol and decamethylene glycol The polyester obtained can be mentioned. Further, the polyester may be blended or copolymerized with another type of polymer within a range that does not impair the object of the present invention, and includes an antioxidant, a heat stabilizer, a lubricant, a pigment, an ultraviolet absorber and the like. It may be. The intrinsic viscosity of the polyester (measured in ortho-chlorophenol at 25 ° C.) is preferably 0.4 to 2.0, more preferably 0.5 to 1.0.

Further, the polyester film used in the present invention may be one in which fine air bubbles are contained in the film and light is scattered by the air bubbles so as to whiten the film. The formation of these fine bubbles is caused by the formation of incompatible polymers such as poly-3-methylbutene-1, poly-4-methylpentene-1, polypropylene, polyvinyl-t-butane, 1, in a film matrix such as polyester.
It is formed by finely dispersing 4-trans-poly-2,3-dimethylbutadiene, cellulose triacetate, cellulose tripropionate, polychlorotrifluoroethylene, etc., and stretching it uniaxially or biaxially. During stretching, voids (air bubbles) are formed around the incompatible polymer particles, and the voids are whitened because they exhibit a light scattering action. Further, since it has fine bubbles, it has a low specific gravity, and since it also has cushioning properties, clear printed matter can be obtained.

When such a bubble-containing polyester film is used, the apparent specific gravity of the bubble-containing polyester film is preferably 0.4 to 1.3, more preferably 0.6 to 1.2. When the apparent specific gravity is lower than the above range, mechanical properties and thermal dimensional stability are poor, which is not preferable.

Further, in the present invention, it is possible to use a polyester film in which fine particles such as calcium carbonate, amorphous zeolite particles, anatase type titanium dioxide, calcium phosphate, silica, kaolin, talc and clay are used in combination. In addition to such fine particles, fine particles precipitated by the reaction of the catalyst residue and the phosphorus compound in the polyester polymerization reaction system may be used in combination.

In the case where the polyester film is subjected to surface treatment by a known method, that is, corona discharge treatment (in air, nitrogen, carbon dioxide, etc.) or easy adhesion treatment, the adhesion to the receiving layer, It is more preferably used because it has improved water resistance and solvent resistance. For the easy-adhesion treatment, various known methods can be used, and various easy-adhesives such as acrylic, urethane, and polyester adhesives are applied in the film process, or the above-mentioned film is uniaxially or biaxially stretched. Those coated with such various types of easy-adhesives can be preferably used.

The substrate film may be a transparent film or a colored film.

The thickness of this substrate is not particularly limited, but is usually preferably 10 μm to 500 μm, more preferably 20 μm to 300 μm, and further preferably 30 μm to 25.
It is preferably 0 μm or less.

In the present invention, as the polymer binder, those containing urethane resin and cationic polymer as main components are used.

Urethane resins are generally obtained by reacting a polyol with a polyisocyanate. Examples of polyols include “Polyurethane” (Maki Shoten, Nobutaka Matsudaira, Tetsuro Maeda, 1960) and “Synthesis and blending of polyurethane, functionalization and application development” (Technical Information Institute, Kazuhiro Takahashi, 1989).
Year) can be used effectively. For example, polypropylene glycol, polyethylene glycol, polytetramethylene glycol, ethyne oxide / propylene oxide copolymer, THF / ethylene oxide copolymer,
Polyether polyol such as THF / propylene oxide copolymer, polyethylene adipate, polydiethylene adipate, polypropylene adipate, polytetramethylene adipate, polyhexamethylene adipate,
Polyene-based polyols such as polyneopentylene adipate, lactone-based polyester polyols and polycarbonate diols can be mentioned.

As the polyisocyanate, the above-mentioned "polyurethane" (Maki Shoten, Nobutaka Matsudaira, Tetsuro Maeda, 1960)
Year)) and “Polyurethane synthesis / blending and functionalization / application development” (Technical Information Association, Kazuhiro Takahashi, 1989) can be effectively used. For example, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate,
Diisocyanate methyl caproate, methylenebiscyclohexyl isocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and tri- and tetraisocyanate may be mentioned. Further, if necessary, a chain extender containing an active hydrogen atom capable of reacting with polyisocyanate can be used.

Among these, a urethane resin obtained by using polypropylene glycol as a polyol and isophorone diisocyanate as a polyisocyanate as a main component is preferable in terms of weather resistance, water resistance, toughness and the like.

In the polymer binder of the present invention, a polymer electrolyte is added to the urethane resin in order to adjust the electric resistance of the receiving layer. As the polymer electrolyte, a cationic polymer such as a quaternary ammonium salt polymer is preferably used from the viewpoint of conductivity and compatibility with urethane resin. A quaternary ammonium salt polymer is a polymer having at least one quaternary ammonium salt in the repeating unit chain and is described in "Surfactant Handbook" (Sangyo Tosho, 1960).
Polymers of the various quaternary ammonium salts and pyridinium salts described can be effectively used. For example, poly (2
-Hydroxy-3-methacryloxypropyltrimethylammonium chloride), poly (2-hydroxy-3-methacryloxypropyltriethylammonium chloride), poly (2-hydroxy2-acryloxypropyltrimethylammonium chloride), poly (2-hydroxy-3-acryloyl) Roxypropyltriethylammonium chloride), poly (2-methacryloxyethyltrimethylammonium chloride), poly (2-methacryloxyethyltriethylammonium chloride), poly (2-acryloxyethyltrimethylammonium chloride), poly (2-acryloxyethyl) Triethylammonium chloride), poly (dimethylaminoethylmethacrylate) salt, poly (diethylaminoethylmethacrylate) Salt, poly (dimethylaminoethyl acrylate) salt, poly (diethylaminoethyl acrylate) salt, poly (vinylbenzyltrimethylammonium chloride), poly (vinylbenzyltriethylammonium chloride), poly (4-vinylN-methylpyridinium chloride), NN dimethyl substitution 3,5-
Examples of the polymer include methylpiperidinium chloride resin, poly (dimethyldiallylammonium chloride), poly (diethyldiallylammonium chloride), polyethyleneimine hydrochloride, and other known quaternary ammonium salts.

In particular, poly (2-hydroxy-3-methacryloxypropyltrimethylammonium chloride),
Poly (2-hydroxy-3-methacryloxypropyltriethylammonium chloride), poly (2-hydroxy2-acryloxypropyltrimethylammonium chloride), poly (2-hydroxy-3-acryloxypropyltriethylammonium chloride), poly (2
-Methacryloxyethyltrimethylammonium chloride), poly (2-methacryloxyethyltriethylammonium chloride), poly (2-acryloxyethyltrimethylammonium chloride), poly (2-acryloxyethyltriethylammonium chloride), poly (dimethylaminoethyl) Methacrylate) salt, poly (diethylaminoethylmethacrylate) salt, poly (dimethylaminoethylacrylate) salt,
A salt of poly (diethylaminoethyl acrylate) is the preferred polymer.

The quaternary ammonium salt polymer may be used alone or in a mixture of two or more kinds. Further, it may be a copolymer of a quaternary ammonium salt and styrene or an acrylic acid ester. The acrylic acid ester as used herein refers to an acrylic acid ester and a methacrylic acid ester, and is preferably an ester of an aliphatic alcohol having 1 to 4 carbon atoms, such as methyl acrylate, ethyl acrylate, butyl acrylate, propyl. Acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, 2-hydroxyethyl methacrylate and the like can be mentioned.

Specific examples of the quaternary ammonium salt polymer used in the present invention include, for example, "elecond".
(Soken Kagaku), “Chemist” (Sanyo Kasei), “Colcoat” (Colcoat), “SAT” -5 (Nippon Pure Chemicals), “Dow ECR” (Dow Chemical) and the like, but are not limited thereto. .

In the present invention, the electric resistance value on the surface of the receiving layer is preferably 5 × 10 ¹³ Ω / □ or less. When the electric resistance value exceeds 5 × 10 ¹³ Ω / □, problems occur in transportability and print quality in the printing process.

The porous particles in the present invention are porous particles having pores on the surface of the particles, and can be freely filled and released with a liquid, a solid or a gas inside as a hollow porous or non-hollow porous form. Those are preferable from the viewpoint of ink absorbency.

The constituents of the porous particles include amorphous silica, anhydrous silica, aluminum silicate, magnesium silicate, zinc silicate, calcium silicate, hydrotalcite, zeolite, satin white, titanium oxide, and oxidation. Aluminum, magnesium oxide, calcium carbonate, calcium sulfate, barium sulfate, diatomaceous earth, kaolin, talc, acid clay, activated clay, bentonite, ion exchange resin powder, urea resin powder, polyethylene resin powder, urea formalin resin powder, acrylic resin Powder, styrene-acrylic resin powder, etc. are mentioned.

The oil absorption of these porous particles is 2
It is necessary to be 100 to 400 ml / 100 g.
When the oil absorption amount is less than 200 ml / 100 g, the absorption property of the oil-based offset ink of the obtained recording sheet is poor, and sufficient ink setting property and ink drying property cannot be obtained.
When the amount exceeds 100 ml / ml, the printed matter obtained becomes lighter,
It tends to be a so-called sunken printed matter.

The average particle size of the porous particles used in the present invention is preferably 0.1 μm to 25 μm, and 0.5 μm to 10 μm.
m is more preferable in terms of handleability, coatability, printability, and the like.

The content of the porous particles in the receiving layer is preferably 2 with respect to 100 parts by weight of the polymer binder.
It is 0 to 100 parts by weight, more preferably 30 to 70 parts by weight. If the content is less than 20 parts by weight, the ink setting property,
If the ink dryness becomes insufficient and the amount exceeds 100 parts by weight, the adhesion between the receiving layer and the film support tends to decrease.

When used as a sheet for electrical decoration, a light-shielding white pigment is added to the receiving layer in the present invention in order to obtain an appropriate total light transmittance and a desired optical density.

The concealing white pigment in the present invention is an inorganic or organic pigment that presents a white receptive layer, and examples of the inorganic pigment include zinc carbonate, zinc oxide and zinc sulfide.
Talc, kaolin, heavy / light or synthetic calcium carbonate, titanium oxide, silica, lithium fluoride, calcium fluoride, barium sulfate, alumina, zirconia, calcium phosphate, natural or synthetic swelling or non-swelling mica, etc. Can be mentioned. Examples of organic pigments include polystyrene, polyvinyl chloride, polyethylene, polypropylene, polyvinylidene chloride, and poly (meth) acrylate copolymers. At least one selected from these is applied. It Further, the pigment may be subjected to a surface treatment, for example, a treatment of adding a functional group such as a glycidyl group or a methylol group, in order to improve dispersibility in the resin.

The amount of the hiding white pigment added is preferably 5 to 100 parts by weight, more preferably 10 to 60 parts by weight, based on 100 parts by weight of the polymer binder. If the addition amount is less than 5% by weight, the desired total light transmittance and optical density cannot be obtained, so the concealing property of the obtained sheet for electric decoration is poor, and when used as an electric signboard, the light source on the back side is transparent. Not visible because it is visible. On the other hand, if the amount added exceeds 100 parts by weight, the adhesiveness to the film support tends to deteriorate, which is not preferable.

When the recording sheet of the present invention is used as a sheet for electrical decoration, the total light transmittance is preferably 30 to 70%. When the total light transmittance is less than 30%, when used as an electric signboard, it is difficult for light from the light source to pass through the electric decorative sheet, which not only darkens the display but also raises the temperature inside the signboard. Therefore, it is not preferable because it may cause a disaster such as a fire. The total light transmittance is 70%
When it exceeds, it is not preferable because the light source part is easily seen through.

The optical density when the recording sheet of the present invention is used as a sheet for electrical decoration is preferably 0.20 to 0.50. When the optical density is less than 0.20,
This is because, when it is used as an illuminated signboard, the light source part is easily seen through, and when it exceeds 0.50, the light from the light source is hard to be transmitted and the display on the sheet surface becomes dark.

The smoothness of the receiving layer constituting the recording sheet of the present invention is preferably 30 to 10000 seconds, more preferably 50 to 5000 seconds. When the smoothness is less than 30 seconds, the ink permeation rate is too high and the printed matter becomes pale, which is not preferable. On the other hand, if it exceeds 10,000 seconds, the ink permeation rate is too low and the ink is likely to remain on the surface of the receiving layer, and when the printing surface is rubbed, the printing surface is likely to be contaminated with residual ink, which is not preferable.

When a white film is used as the base material of the recording sheet of the present invention, the whiteness of the recording sheet is preferably 50% or more, more preferably 60% or more. Whiteness is 5
If it is 0% or more, the sharpness and density gradation of the printed matter are improved, and a good printed matter can be obtained.

Further, the thickness of the receiving layer constituting the recording sheet of the present invention is not limited, but is 1.0 μm or more.
50 μm is preferable, and more preferably 3.0 μm to 3
Those in the range of 0 μm are desirable in terms of uniform forming property of the receiving layer and adhesion. Further, the receiving layer may optionally contain known additives such as a coatability improver, a thickener, an antioxidant, an ultraviolet absorber and a dye, as long as the characteristics of the present invention are not impaired. .

In the present invention, when used as a recording sheet,
It is preferable to add an antistatic function from the viewpoint of adhesion of dust due to static electricity and running property. In order to impart antistatic properties, it is desirable to provide a receptive layer on one surface of the substrate and an antistatic layer on the other surface, or to add an antistatic agent to the receptive layer.

The antistatic layer in the present invention is a coating layer made of an antistatic agent, a resin layer containing an antistatic agent, a vapor deposition layer made of a metal or a metal oxide, etc. Examples include certain surfactants, conductive polymers, conductive carbon fine particles, metal or metal oxide fine particles, and the like. The antistatic property preferably has a surface resistance value of 5 × 10 ¹³ Ω / □ or less. More preferably 5 × 10 ¹² Ω
/ □ or less.

In the present invention, the method of providing the receiving layer is as follows. In the film forming step, the film support which is the base material is previously stretched, and then a liquid adjusted to a predetermined amount is applied,
After that, a method of providing a coating-drying step after winding the substrate film as a single film is preferably applied.

The coating method is not particularly limited, but gravure coating method, reverse coating method, reverse gravure coating method, kiss coating method, die coating method, metalling bar coating method, etc., because thin film coating can be performed at high speed. Known methods can be applied. The coating speed,
The coating film drying conditions are not particularly limited, but it is desirable that the coating film drying conditions be performed within a range that does not adversely affect various properties of the receiving layer and the support.

[0048]

[Characteristic Measuring Method] First, various characteristic measuring methods in the present invention will be described.

(1) Smoothness Oken type smoothness tester (Model KB-15) manufactured by Asahi Seiko Co., Ltd.
It was measured at. The average is shown as n = 5.

(2) Adhesiveness of Receptor Layer The adhesiveness of the receptive layer / support is determined by putting a crosscut (100 pcs / cm ² ) on the receptive layer and making "Cellotape" CT at 45 ° to the crosscut surface. -24 (Nichiban Co., Ltd.)
Manufactured) was applied, and reciprocating was repeated 10 times under a load of about 5 kg using a hand roller, the “cellophane tape” was forcibly peeled in the direction of 180 °, and the peeling degree of the receptor layer was observed and evaluated.
The criteria for judgment are as follows.

◎: Very good (no peeling) ○: Good (peeling area less than 5%) △: Slightly inferior (peeling area 5% or more and less than 10%) ×: Poor (peeling area 10% or more)

(3) Water Receptive Layer Water Resistance A cotton swab was dipped in water and the receptor layer was lightly rubbed for evaluation. The criteria for judgment are as follows.

⊚: Very good (no peeling at all) ○: Good (peeling after rubbing 10 times or more but less than 15 times) Δ: Slightly inferior (peeling after rubbing 5 times or more but less than 10 times) ×: Poor (with less than 5 times) Peel off)

(4) Heat resistance A hot air oven (model PHH-20, manufactured by Tabai Co., Ltd.)
0) is set to 140 ° C., the measurement sample is placed in a hot air oven for 1 hour, and if there is no change, “good”, melting
Those having a change in the receiving layer such as deformation were defined as "poor".

(5) Receptive layer thickness Measured with a micrometer or dial gauge.

(6) Ink setting property A printability tester RI-2 type (manufactured by Akira Seisakusho Co., Ltd.) was set with 4-division rolls having a diameter of 6.5 cm and a width of 4.7 cm, and an oil-based offset was set on each roll. Printing ink "TK Mark Five New" Beni (Toyo Ink Co., Ltd.)
0.3 cc was prepared with an ink pipettor, and solid coating printing was performed. Next, measure the time until the coated surface of OK coated paper (manufactured by Oji Paper Co., Ltd.) is overlaid on the printed surface, and a metal roll with a linear pressure of 353 g / cm is run to prevent transfer to OK coated paper. Then, the judgment was made according to the following judgment criteria.

◎: Within 30 minutes ○: From 30 minutes to less than 45 minutes △: From 45 minutes to less than 60 minutes ×: From 60 minutes or more

(7) Ink drying property Printing was carried out in the same manner as the measurement of the ink setting time, the coated surface of the OK coated paper was superposed on the printed surface, and the printed surface was left standing for 24 hours, and the printed surface was clawed. It was rubbed lightly and evaluated. The criteria for judgment are as follows.

◯: Not peeled off Δ: Peeled off after repeated rubbing ×: Easily peeled off

(8) Total light transmittance SPHERE METHOD M manufactured by Japan Precision Optical Co., Ltd.
550 with ETER (TYPESEP-HS)
The total light transmittance Tt (%) in nm was obtained.

(9) Optical Density The optical density was measured using a "Macbeth" densitometer TR-927 manufactured by Macbeth.

(10) Whiteness It was measured according to JIS L-1015 using a color difference meter ND-K6B manufactured by Nippon Denshoku Industries Co., Ltd.

(11) Oil Absorption of Porous Particles The oil absorption was measured according to JIS-K-5101 to obtain an oil absorption (ml) corresponding to 100 g of particles.

(12) Appearance of coating film It was visually evaluated according to the following criteria.

⊚: Very good with no lumps and repellence ◯: Good with little lumps and repellence Δ: Poor with lumps and repellency a little inferior ×: Many lots of repellency and bad repellency

(13) Specific gravity The film was cut into 100 × 100 mm squares, and a dial gauge (No. 2109-10, manufactured by Mitoyo Seisakusho) was used to obtain a diameter of 10 m.
The thickness of a minimum of 10 points is measured with the one to which the m measuring element (No. 7002) is attached, and the average value d (μm) of the thickness is calculated. In addition, this film is weighed with a direct balance and the weight w (g) is read to the unit of 10 ⁻⁴ g. At this time,
Specific gravity = (w / d) × 100.

[0067]

EXAMPLES Next, the present invention will be specifically described by way of examples. The blending amount described below is a solid content weight ratio unless otherwise specified.

Example 1 Polyethylene terephthalate homopolymer chips produced by a conventional method (intrinsic viscosity: 0.62, melting point: 25)
9 ° C) and a specific gravity of 1.4 and a thickness of 100 by a conventional method.
A transparent biaxially stretched polyester film of μm was obtained. Corona discharge treatment was performed on the polyester film thus obtained. Next, urethane resin (“Olestar” NL2532, solid content 30%, manufactured by Mitsui Toatsu Chemicals) 8
0 parts by weight, cationic polymer ("Elecond" PQ50
B, solid content 50%, Soken Chemical Co., Ltd. 20 parts by weight and silica particles as porous particles (“FINESEAL” T-32S,
50 parts by weight of an average particle size of 1.0 μm, oil absorption of 290 ml / 100 g, manufactured by Tokuyama Soda Co., Ltd. are mixed with a toluene / MEK mixed solvent (1
The coating material diluted / dispersed to 20% in 1) was applied to one surface of the polyester film by a reverse coating method so that the dry film thickness was 8 μm, to obtain the recording sheet of the present invention. The properties of the recording sheet thus obtained are as shown in Table 1 and were excellent in the receptive layer adhesion, heat resistance, water resistance, ink setting property, ink drying property and coating film appearance.

Example 2 Polyethylene 2,6-naphthalate homopolymer chip produced by a conventional method (intrinsic viscosity [η] = 0.7)
Was sufficiently dried in vacuum, supplied to an extruder, melt-extruded at 295 ° C., filtered through a 10 μm-cut metal sintering filter, and then extruded into a sheet from a T-shaped die, which was cooled at a surface temperature of 50 ° C. It was wrapped around and solidified by cooling. In order to improve the adhesion between the sheet and the surface of the cooling drum during this period, a wire electrode was arranged on the sheet side and a DC voltage of 6000 V was applied. The thus-obtained unstretched polyethylene 2,6-naphthalate film was stretched 4.5 times in the longitudinal direction by a roll group heated to 120 ° C. and cooled to 25 ° C. to obtain a uniaxially stretched film. Corona discharge treatment was performed on the film thus obtained, and a recording sheet of the present invention was obtained on the treated surface in the same manner as in Example 1. The properties of the recording sheet thus obtained are as shown in Table 1 and were excellent in the receptive layer adhesion, heat resistance, water resistance, ink setting property, ink drying property and coating film appearance.

Further, since the biaxially stretched polyethylene 2,6-naphthalate film is used as the substrate, no deterioration in the flatness of the printed part due to heat shrinkage is observed, and the heat resistance is excellent. It was

Example 3 Polyethylene terephthalate chips and molecular weight 40
The master chip to which polyethylene glycol of 00 was added at the time of polymerization of polyethylene terephthalate was dried in vacuum at 180 ° C., and then mixed so that 89% by weight of polyethylene terephthalate, 1% by weight of polyethylene glycol and 10% by weight of polymethylpentene were mixed, 300
Feed to extruder B heated to ° C. Further, after drying polyethylene terephthalate containing 10% by weight of calcium carbonate having an average particle diameter of 1.0 μm as described above,
Supply to extruder A. Polymers extruded from extruders A and B are laminated so as to have a three-layer structure of A / B / A, and T
Molded into a sheet from a die. Further, the unstretched film obtained by cooling and solidifying this film with a cooling drum having a surface temperature of 25 ° C. was guided to a roll group heated to 85 to 95 ° C., stretched 3.4 times in the longitudinal direction, and cooled by a roll group of 25 ° C. Subsequently, the longitudinally stretched film was guided to a tenter while holding both ends with clips, and stretched 3.6 times in the direction perpendicular to the longitudinal direction in an atmosphere heated to 130 ° C. After that, heat setting was carried out at 230 ° C. in a tenter, and after uniform uniform cooling, it was cooled to room temperature and wound up to obtain a white film having a thickness of 100 μm and a specific gravity of 1.0. The laminated structure of the film is 5/90 / 5μ
It was m. On top of the polyester film obtained by the above method, the coating material of Example 1 was further coated with silica particles ("Fineseal" X-37B, average particle size 3.5 μm, oil absorption 27).
A recording sheet of the present invention was obtained in the same manner except that 5 parts by weight (5 ml / 100 g, manufactured by Tokuyama Soda) was added. The coated surface of the PET film was one that had been subjected to corona discharge treatment in air. The characteristics of this recording sheet are shown in Table 1. As is clear from Table 1, the properties were excellent in the receptive layer adhesion, heat resistance, water resistance, ink setting property, ink drying property, and coating film appearance.

Example 4 Polyethylene 2,6-naphthalate (intrinsic viscosity [η]
= 0.7) 94% by weight, poly-4-methylpentene-
1 (TPX-D820 manufactured by Mitsui Petrochemical Co., Ltd.) 5% by weight, polyethylene glycol having a molecular weight of 4000 1% by weight
The raw material, which had been pre-pentalized at a ratio of 1, was supplied to the extruder A, melted at 295 ° C. by a conventional method, and introduced into the center of the T-die three-layer die.

On the other hand, 86% by weight of the above-mentioned polyethylene 2,6-naphthalate was added to calcium carbonate (average particle size 0.8 μm).
m) was added to Extruder B, melted at 295 ° C. by a conventional method, laminated on both surface layers of a T-die three-layer die, and the melted sheet was cooled at a surface temperature of 25 ° C. The drum was adhered onto the drum by the electrostatic charge method and solidified by cooling. The thus-obtained sheet was stretched 3.5 times in the longitudinal direction by a roll group heated to 120 ° C. and cooled to 25 ° C. to obtain a uniaxially stretched film according to a conventional method. Further, the film is guided to a tenter, and 3. in the width direction in an atmosphere heated to 125 ° C.
Stretched 2 times and heat set at 225 ℃, thickness 100μ
A biaxially stretched film having m and a specific gravity of 1.0 was obtained. The thickness of each film layer was 6 μm on the surface layer and 88 μm on the central layer.

The film thus obtained was subjected to corona discharge treatment, and a recording sheet of the present invention was obtained on the treated surface in the same manner as in Example 3. The properties of the recording sheet thus obtained are as shown in Table 1 and were excellent in the receptive layer adhesion, heat resistance, water resistance, ink setting property, ink drying property and coating film appearance.

Further, since the biaxially stretched polyethylene 2,6-naphthalate film is used as the substrate, no deterioration in the flatness of the printed part due to heat shrinkage is observed, and the heat resistance is excellent. It was

Example 5 The coating material of Example 1 was further coated with TiO ₂ as a hiding white pigment.
Particles (average particle size 0.3 μm, oil absorption 20 ml / 100
g) 20 parts by weight was added, both surfaces of the polyester film obtained in Example 1 were subjected to corona discharge treatment, and both surfaces were coated by the reverse coating method so that the dry coating film was 5 μm each, and the decoration of the present invention was applied. A recording sheet for a printing sheet was obtained. The characteristics of this recording sheet are shown in Table 1. As is clear from Table 1, the properties are excellent in the receptive layer adhesiveness, heat resistance, water resistance, ink setting property, ink drying property, and coating film appearance, and the desired total light transmittance and optical density are obtained. And showed excellent characteristics as a sheet for electric decoration.

Comparative Example 1 Calcium carbonate particles (NS # 2300, average particle size 0.97 μm, in place of silica particles in the coating material of Example 1;
A recording sheet was obtained in the same manner except that an oil absorption amount of 35 ml / 100 g, manufactured by Nitto Koka Co., Ltd. was used. This recording sheet is shown in Table 2.
As shown in, the ink setting property and the ink drying property were inferior.

Comparative Example 2 A recording sheet was obtained in the same manner as in Example 1 except that the porous particles were removed. As shown in Table 2, this recording sheet was inferior in ink setting property and ink drying property.

[0079]

[Table 1]

[Table 2]

[0080]

INDUSTRIAL APPLICABILITY The recording sheet of the present invention has an ink receiving layer provided on at least one side of a base material, and has a good printability by applying a specific receiving layer. Ink can be used, and there is no set-off of the ink during the offset printing process, and it has excellent ink transfer properties, ink setting properties, ink drying properties, antistatic properties, and blocking resistance. Further, by adjusting the total light transmittance and the optical density, it can be preferably used in applications such as an electric signboard.

When polyethylene 2,6-naphthalate is used as the base material, a recording sheet excellent in heat resistance and strength can be obtained.

Since the recording sheet of the present invention thus obtained has excellent properties, inks and toners such as sublimation type thermal ink receivers, electrophotographic toner receivers, fabric ribbon ink receivers, ink jet receivers and the like ( It can also be applied as dry and wet) acceptor.

Claims (11)

[Claims] 1. A recording sheet comprising a base material and a receptor layer containing a polymeric binder and porous particles having an oil absorption of 200 to 400 ml / 100 g on at least one side of the substrate, wherein the polymeric binder is urethane. A recording sheet comprising a resin and a cationic polymer as main components. 2. The recording sheet according to claim 1, wherein the urethane resin is mainly obtained by a reaction of polypropylene glycol and isophorone diisocyanate. 3. A recording sheet comprising a base material and a receiving layer containing a polymeric binder, porous particles having an oil absorption of 200 to 400 ml / 100 g, and a masking white pigment on at least one side of the substrate. A recording sheet characterized in that the binder comprises a urethane resin and a cationic polymer as main components. 4. The recording sheet according to claim 3, wherein the urethane resin is mainly obtained by a reaction of polypropylene glycol and isophorone diisocyanate. 5. The recording sheet according to claim 1, wherein the base material is a polyester film. 6. The recording sheet according to claim 1, wherein the substrate is a transparent polyester film, and the optical density of the recording sheet is 0.20 to 0.50. 7. The substrate is a white polyester film having an apparent specific gravity of 0.4 to 1.3.
~ The recording sheet according to claim 6. 8. The recording sheet according to claim 1, wherein the base material is a white polyester film, and the whiteness of the recording sheet is 50% or more. 9. The recording sheet according to claim 1, wherein the base material has a receiving layer on one surface and an antistatic layer on the other surface. 10. The recording sheet according to claim 1, wherein the base material is polyethylene 2,6-naphthalate. 11. The recording sheet according to claim 1, wherein the receptive layer has a film thickness of 1.0 μm or more and a smoothness of 30 seconds or more.