WO2021084970A1 - Recording paper and recording label - Google Patents

Abstract

The present invention provides recording paper and recording label having excellent printing properties and wet abrasion resistance without reducing productivity.　The recording paper includes a base material comprising a thermoplastic resin film and a coat layer on at least one surface of the base material. The coat layer contains an inorganic filler, isocyanate-modified polyethylene glycol, and a binder. In the coat layer, the inorganic filler content is 47 to 83% by mass, and the isocyanate-modified polyethylene glycol content is 0.3 to 4.0% by mass.

Description

Recording paper and recording labels

The present invention relates to recording paper and recording labels.

Offset printing is the mainstream printing method because it enables high-speed and mass printing. Gloss ghost is known as one of the printing troubles peculiar to offset printing. When printing on both sides of a sheet of paper, gloss ghost causes a gloss difference between the part that overlaps with the image part of the preprint and the part that does not overlap with the image part of the postprint, and the image part of the postprint is printed with the preprint. This is a phenomenon in which a pattern caused by an image portion appears.

As the sheet-fed paper, a recording paper in which a coat layer is provided on the surface of the paper or a resin film and a pigment is mixed in the coat layer may be used. The solvent in the ink is absorbed by the pores between the pigment particles, so that the image portion formed of the ink on the coat layer dries. Insufficient drying of the ink can contribute to the above-mentioned gloss ghosting.

In order to form sufficient pores, it is effective to suppress the binder migration that occurs when the coat layer is formed. The coat layer can be formed by coating, but if the drying after coating is rapid, binder migration may occur in which the binder component moves to the surface of the coating layer. When binder migration occurs, the pores on the surface of the coat layer are filled with the binder, which not only reduces the dryness of the ink, but also causes phase separation of the material in the coat layer, resulting in adhesion between the base material and the coat layer. It may also lead to a decrease in sex.

Conventionally, casein was blended in the coat layer in order to suppress binder migration (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 61-13897

However, a relatively large amount is required to obtain a sufficient effect of casein. Since the viscosity of the coating liquid in the coat layer tends to increase, there is room for improvement in productivity.

An object of the present invention is to provide a recording paper and a recording label having good printing characteristics and water scratch resistance without reducing productivity.

As a result of diligent studies to solve the above-mentioned problems, the present inventors can solve the above-mentioned problems by blending an isocyanate-modified polyethylene glycol instead of casein in a coat layer containing an inorganic filler, particularly calcium carbonate, and a binder. We found what we could do and completed the present invention.
That is, the present invention is as follows.

(1) A recording paper having a base material made of a thermoplastic resin film and a coat layer on at least one surface of the base material.
The coat layer contains an inorganic filler, isocyanate-modified polyethylene glycol and a binder.
In the coat layer, the content of the inorganic filler is 47 to 83% by mass, and the content of the isocyanate-modified polyethylene glycol is 0.3 to 4.0% by mass.
Recording sheet.

(2) The average primary particle size (D50) of the inorganic filler is 0.03 to 2.00 μm.
The recording paper according to (1) above.

(3) The coat layer contains at least calcium carbonate as the inorganic filler.
The recording paper according to (1) or (2) above.

(4) The coat layer contains calcium carbonate and kaolin as the inorganic filler, and the coat layer contains calcium carbonate and kaolin.
The content of the calcium carbonate and the kaolin in the coat layer is 97: 3 to 60:40 by mass ratio.
The recording paper according to any one of (1) to (3) above.

(5) The coat layer contains a surfactant.
The recording paper according to any one of (1) to (4) above.

(6) The content of the surfactant in the coat layer is 0.6 to 4.5% by mass.
The recording paper according to (5) above.

(7) The coat layer contains, as the binder, at least one selected from the group consisting of a styrene-butadiene copolymer, a styrene-acrylic copolymer and an ethylene-vinyl acetate copolymer.
The recording paper according to any one of (1) to (6) above.

(8) The coat layer contains one or more cross-linking agents selected from the group consisting of a metal-based cross-linking agent, an epoxy-based cross-linking agent, an epichlorohydrin-based cross-linking agent, and an oxazoline-based cross-linking agent.
The binder is crosslinked by the crosslinker,
The recording paper according to any one of (1) to (7) above.

(9) The content of the binder in the coat layer is 15 to 45% by mass.
The recording paper according to any one of (1) to (8) above.

(10) The solid content per unit area of the coat layer is 7 to 30 g / m ² .
The recording paper according to any one of (1) to (9) above.

(11) The base material is a porous film containing a thermoplastic resin and a filler.
The recording paper according to any one of (1) to (10) above.

(12) The recording paper according to any one of (1) to (11) above, and
It has an adhesive layer provided on a surface opposite to the coat layer of the recording paper.
Recording label.

According to the present invention, it is possible to provide a recording paper and a recording label having good printing characteristics and water scratch resistance without lowering the productivity.

It is sectional drawing which shows the structure of the recording paper of one Embodiment. It is sectional drawing which shows the structure of the label for recording of one Embodiment.

Hereinafter, the recording paper and the recording label of the present invention will be described in detail. The following description is an example (representative example) of the present invention, and the present invention is not specified in these contents.

In the following description, the description of "(meth) acrylic" indicates both acrylic and methacrylic.

(Recording sheet)
The recording paper of the present invention has a base material and a coat layer provided on at least one surface of the base material.

FIG. 1 shows a configuration example of recording paper 1 which is an embodiment of the present invention.
The recording paper 1 illustrated in FIG. 1 has a base material 11 and a coat layer 12. The coat layer 12 is provided on one surface of the base material 11, but may be provided on both surfaces.

The recording paper of the present invention may have layers other than the base material and the coat layer as long as the effects of the present invention are not impaired. For example, an intermediate layer may be provided between the base material and the coat layer for the purpose of improving the adhesion between the base material and the coat layer. Further, a surface layer may be provided on the surface of the base material opposite to the coat layer for the purpose of preventing blocking or the like.

<Coat layer>
The coat layer contains an inorganic filler, isocyanate-modified polyethylene glycol and a binder. In the coat layer, the content of the isocyanate-modified polyethylene glycol is 0.3 to 4.0% by mass, and the content of the inorganic filler is 47 to 83% by mass.

The coat layer containing the inorganic filler has pores between the particles of the inorganic filler, and the solvent in the ink transferred onto the coat layer by printing permeates into the pores to allow the ink to dry. Can be done. By blending a specific amount of the inorganic filler, pores sufficient for absorbing the solvent can be formed, and excellent ink drying property can be obtained. In the case of the oxidative polymerization type ink, the solvent is absorbed and the oxidative polymerization reaction of the ink component remaining on the coat layer proceeds, so that the drying proceeds. Therefore, the coat layer having high solvent absorbency is particularly effective for improving the drying property of the oxidative polymerization type ink.

If the ink in the coat layer is highly dry in this way, gloss ghosts are unlikely to occur. In addition, it is difficult for backing to occur when the recording papers after printing are stacked, and the dryness of the heavy-colored portion is high.

When the coat layer is formed by coating, when the coating film is rapidly dried, binder migration occurs in which the binder moves to the surface of the coat layer, and the pores on the surface are easily filled by the binder. However, by blending the above-mentioned specific amount of isocyanate-modified polyethylene glycol with the above-mentioned specific amount of the inorganic filler, binder migration can be suppressed even in the case of rapid drying, and the drying property of the ink due to the burial of pores can be suppressed. The decrease can be effectively suppressed.

Conventionally, casein was blended to suppress binder migration, but by using isocyanate-modified polyethylene glycol instead of casein, a sufficient suppressing effect can be obtained with a smaller blending amount than casein. Therefore, it is possible to suppress an increase in the viscosity of the coating liquid for the coat layer. Process control such as adjusting the concentration of the coating liquid becomes easy, and the productivity of recording paper is also improved.

Hereinafter, each component of the coat layer will be described.

<< Inorganic filler >>
The coat layer contains an inorganic filler. By randomly aggregating the particles of the inorganic filler in the coat layer, fine pores between the particles spread over the entire coat layer and quickly absorb the solvent of the ink, so that excellent ink drying property can be obtained.

Among the inorganic fillers, calcium carbonate is preferable because the whiteness is easily improved.
Examples of calcium carbonate include heavy calcium carbonate and light calcium carbonate. Of these, light calcium carbonate is preferable from the viewpoint of forming fine pores.

The average primary particle size (D50) of the inorganic filler is preferably 0.03 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, from the viewpoint of improving the ink drying property by forming fine pores. .. On the other hand, the average primary particle size is preferably 2.0 μm or less, more preferably 1.0 μm or less, still more preferably 0.5 μm or less, from the viewpoint of suppressing dropping from the coat layer.

The average primary particle size (D50) is measured by a laser light diffraction / scattering method. For the measurement, for example, Microtrack MT3300EXII (manufactured by Microtrack Bell) can be used.

The content of the inorganic filler in the coat layer is 47% by mass or more and 83% by mass or less as described above. Within this range, sufficient pores can be formed to obtain excellent drying properties of the ink. Among them, the content is preferably 50% by mass or more from the viewpoint of ensuring a sufficient porosity. The content is preferably 80% by mass or less from the viewpoint of the toughness of the coat layer itself.

The inorganic filler in the coat layer may be only one type, but two or more types may be used in combination from the viewpoint of ink drying property and cost. Calcium carbonate is preferable as the inorganic filler, but for example, calcium carbonate may be used in combination with one or more of kaolin, zeolite, calcium silicate, aluminum hydroxide, calcined clay, talc, or white carbon. preferable.

The average particle size of calcium carbonate is preferably in the above range, but the average particle size of the inorganic filler used in combination with this is preferably 5 μm or less, more preferably 1 μm or less, and 0. 5 μm or less is more preferable. Further, from the viewpoint that fine pores can be formed, it is preferable that the average particle size is small, but if it is very small, agglomeration may occur in the coating liquid for forming a coat layer, and it is 0 in consideration of handleability. It is preferably about 0.05 μm or more.

Of these, kaolin is preferable because it has a plate-like crystal shape and is effective in preventing drydown.
When calcium carbonate and kaolin are used in combination, it is preferable to replace 3 to 40% by mass of calcium carbonate in the coat layer with kaolin. In other words, the mass ratio of the content of calcium carbonate and kaolin in the coat layer is preferably 97: 3 to 60:40 from the viewpoint of the balance between ink dryness and drydown suppression.

<< Isocyanate-modified polyethylene glycol >>
The isocyanate-modified polyethylene glycol functions as a medium modifier in the coat layer. The isocyanate-modified polyethylene glycol is uniformly dispersed in the coat layer to suppress the occurrence of binder migration.

Isocyanate-modified polyethylene glycol is polymerized by urethane bonding, which improves the modifying effect of the medium such as water in the coating liquid for the coat layer. Therefore, even if the blending amount of polyethylene glycol is small, the binder can be sufficiently dispersed, and it is possible to avoid an increase in the viscosity of the coating liquid due to an increase in the blending amount. Process control such as adjusting the concentration of the coating liquid becomes easy, and the productivity of recording paper is improved.

The isocyanate-modified product of polyethylene glycol is not particularly limited as long as it is a compound in which polyethylene glycol is modified with isocyanate, and examples thereof include a modified product obtained by adding an isocyanate compound to polyethylene glycol and reacting it. The amount of the isocyanate compound added to the polyethylene glycol is preferably about 0.01 to 5% by mass. Examples of commercially available products of such modified products include Melpole F-220 (manufactured by Sanyo Chemical Industries, Ltd.) and the like.

The isocyanate compound used for the modification may have one isocyanate group, and a compound having two or more isocyanate groups is preferable. Examples of isocyanate compounds that can be used include propyl isocyanate, butyl isocyanate, hexyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, benzyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, p-nitrophenyl isocyanate, and 2-chloroethyl. Preferred examples thereof include isocyanate, stearoyl isocyanate, propanediisocyanate, hexanediisocyanate, decandiisocyanate, hexanefluoropropanediisocyanate, and 1,4-phenylenediisocyanate.
These isocyanate compounds can be used alone or in combination of two or more, and are produced by reacting with polyethylene glycol in a solution state with an appropriate solvent.

The number average molecular weight Mn of the isocyanate-modified product of polyethylene glycol is usually 5,000 or more, preferably 10,000 or more, and more preferably 15,000 or more. The equal number average molecular weight Mn is usually 2,000,000 or less, preferably 1,000,000 or less, and more preferably 100,000 or less. The number average molecular weight Mn can be obtained as a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

The content of isocyanate-modified polyethylene glycol in the coat layer is 0.3 to 4.0% by mass as described above. The content is preferably 0.4% by mass or more, more preferably 0.5% by mass or more, from the viewpoint of the binder migration suppressing effect. Further, the content is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of not impairing the water scratch resistance of the coat layer.

The content of the isocyanate-modified polyethylene glycol in the coat layer with respect to the binder is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and 2.0% by mass from the viewpoint of the binder migration suppressing effect. The above is more preferable. Further, the content is preferably 20.0% by mass or less, more preferably 15.0% by mass or less, still more preferably 10% by mass or less, from the viewpoint of not impairing the water scratch resistance of the coat layer.

<< Binder >>
The binder has a function of uniformly presenting particles of the inorganic filler in the coat layer. In addition, the binder can improve the water resistance of the coat layer, improve the adhesion between the inorganic filler and the base material, and improve the water scratch resistance of the recording paper.

As the binder, a conventionally known binder can be used, for example, a styrene-butadiene copolymer, a styrene-acrylic copolymer, an ethylene-vinyl acetate copolymer, a butadiene-methylmethacrylate copolymer, a vinyl acetate-. Examples thereof include various copolymers such as butyl acrylate-based copolymers, polyvinyl alcohols, maleic anhydride copolymers, and acrylic acid-methyl methacrylate-based copolymers. Of these, one type can be used alone or two or more types can be used in combination.

In the present invention, any of the above binders can be preferably used, but from the viewpoint of adhesion between the base material and the coat layer, the coat layer may be a styrene-butadiene copolymer or styrene-acrylic as a binder. It is preferable to contain at least one selected from the group consisting of a copolymer and an ethylene-vinyl acetate copolymer.

The content of the binder in the coat layer is preferably 15% by mass or more, more preferably 17% by mass or more, further preferably 18% by mass or more, from the viewpoint of adhesion between the inorganic fillers and between the inorganic filler and the base material. preferable. Further, the content is preferably 45% by mass or less, more preferably 35% by mass or less, still more preferably 25% by mass or less, from the viewpoint of ensuring a sufficient porosity in the coat layer.

<< Crosslinking agent >>
It is preferable that the coat layer further contains a cross-linking agent, and the binder in the coat layer is cross-linked by the cross-linking agent. By cross-linking the binder, the water scratch resistance of the image portion on the surface of the coat layer can be further improved.

As the cross-linking agent, a conventionally known cross-linking agent can be used. Examples of the cross-linking agent that can be used include a metal-based cross-linking agent such as ammonium carbonate, an epoxy-based cross-linking agent such as polyglycerol polyglycidyl ether, a polyamide epichlorohydrin resin, a polyamine epichlorohydrin resin, and a polyamine polyamide epichlorohydrin. Examples thereof include epichlorohydrin-based cross-linking agents such as phosphorus adducts, and oxazoline-based cross-linking agents such as oxazoline group-containing polymers.

From the viewpoint of improving the water-scratch resistance of the surface of the coat layer, the coat layer is one selected from the group consisting of the metal-based cross-linking agent, the epoxy-based cross-linking agent, the epichlorohydrin-based cross-linking agent and the oxazoline-based cross-linking agent. Based on the above, the binder is preferably crosslinked by these cross-linking agents, and the cross-linking agent is preferably one or more selected from the group consisting of the above-mentioned metal-based cross-linking agent and epoxy-based cross-linking agent. Further, from the viewpoint of improving the water resistance and adhesion of the coat layer, the coat layer preferably contains a metal-based cross-linking agent as a cross-linking agent, and among the metal-based cross-linking agents, ammonium carbonate is more preferable. In particular, by using a styrene-acrylic copolymer as a binder and cross-linking the styrene-acrylic copolymer with ammonium carbonate, the water-scratch resistance and water-adhesion resistance of the coat layer can be further enhanced.

The content of the cross-linking agent in the coat layer is preferably 0.4 to 4.0% by mass. Within this range, sufficient cross-linking tends to increase water scratch resistance. From the viewpoint of water scratch resistance of the coat layer, it is more preferably 0.5% by mass or more, and further preferably 0.6% by mass or more. Further, from the viewpoint of adjusting the viscosity of the coating liquid for forming the coat layer and obtaining good coatability, the content is more preferably 2.0% by mass or less, further preferably 1.0% by mass or less.

<< Surfactant >>
The coat layer preferably further contains a surfactant. The surfactant can quickly attenuate the charge even when the surface of the coat layer is charged by friction. Therefore, it is possible to reduce transport troubles such as double feeding during printing of recording paper, sticking to printing members, paper jams, and misalignment.

As the surfactant, any of cationic, anionic, nonionic, amphoteric and the like can be used, but anionic surfactants are preferable. As the anionic surfactant, for example, sodium dioctyl sulfosuccinate is preferable.

By blending a surfactant into the coat layer, the friction zone voltage on the layer surface can be attenuated, but on the other hand, the water resistance of the layer itself tends to decrease. In order to achieve both the frictional band voltage attenuation on the surface of the coat layer and the water resistance and adhesion of the coat layer itself, it is necessary to minimize the amount of the surfactant to be blended. Specifically, the content of the surfactant in the coat layer is preferably 0.6% by mass or more, more preferably 0.7% by mass or more, from the viewpoint of friction zone voltage attenuation. Further, the content is preferably 4.5% by mass or less, more preferably 2.3% by mass or less, from the viewpoint of water resistance and adhesion.

The coat layer may contain other additives, if necessary, as long as the effects of the present invention are not impaired. Examples of additives that can be used include dispersants, thickeners, water retention agents, water resistant agents, colorants, preservatives and the like. As the dispersant, for example, polycarboxylic acid or the like can be usually blended in an amount of 0.05 to 5% by mass.

<< Solid content >>
Binder migration in the layer is likely to occur when the solid content (mass after drying) per unit area of the coat layer is small, that is, when the layer is thin or when the coat layer after coating is rapidly dried. Therefore, from the viewpoint of suppressing binder migration, solid content per unit area of the coating layer is preferably from 7 g / ^{m 2} or more, more preferably 10 g / ^{m 2} or more, further preferably 15 g / ^{m 2} or more. Also from the viewpoint of binder migration resistant, but who the solid content often preferred, is preferably from about normal 30 g / m ² as a coating layer of the recording paper, 20 g / m ² or less is more preferable. Thus, solid content per unit area of the coating layer is preferably from 7 ~ 30g / ^{m 2,} more preferably 10 ~ 20g / ^{m 2.}

For the solid content per unit area of the coat layer, after measuring the mass of the base material with the coat layer of a certain area, the mass of the base material after scraping off the coat layer is measured, and the mass difference is measured by the above-mentioned constant area. Measured by dividing.

<Base material>
The base material is made of a thermoplastic resin film and imparts mechanical strength to the recording paper. The base material is preferably a porous film containing a thermoplastic resin and a filler. If it is a porous film, the whiteness of the recording paper can be easily adjusted.

<< Thermoplastic resin >>
The thermoplastic resin that can be used as the base material is not particularly limited, but for example, an ethylene resin such as high density polyethylene and medium density polyethylene, a propylene resin such as polypropylene, poly (4-methylpenta-1-ene), and an ethylene-cyclic resin. Polyethylene-based resins such as cycloolefin copolymers such as olefin copolymers; polyamide-based resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12; polyethylene terephthalates and copolymers thereof, Thermoplastic polyester resins such as polyethylene naphthalate, polybutylene terephthalate, and aliphatic polyesters; styrene resins such as atactic polystyrene, syndiotactic polystyrene, styrene-acrylonitrile resin, acrylonitrile-butadiene-styrene resin; polycarbonate, polyphenylene sulfide, etc. Examples thereof include thermoplastic resins capable of stretch molding. These can be used alone or in combination of two or more.

Of these, polyolefin resins are preferable from the viewpoints of productivity, ease of processing, water resistance, chemical resistance, recyclability and cost. Among the polyolefin-based resins, propylene-based resin or high-density polyethylene is preferable, and propylene-based resin is more preferable.
Examples of the propylene-based resin include isotactics, syndiotactics, propylene homopolymers exhibiting various stereoregularities, and propylene as a main component, and the propylene and ethylene, butene-1, hexene-1, and heptene-1, Examples thereof include a propylene copolymer with an α-olefin such as 4-methylpentene-1. The copolymer may be a binary system, a ternary system, a quaternary system, a random copolymer, or a block copolymer.

When the base material is a porous film, the content of the thermoplastic resin in the base material is 35% by mass or more from the viewpoint of imparting sufficient strength to the thermoplastic resin film and preventing breakage during stretch molding. Preferably, 50% by mass or more is more preferable, and from the viewpoint of securing sufficient pores and imparting whiteness and opacity, 92% by mass or less is more preferable, and 86% by mass is more preferable.

When a propylene-based resin is used, from the viewpoint of improving stretchability, a thermoplastic resin having a lower melting point than the propylene-based resin, such as polyethylene, polystyrene, or ethylene-vinyl acetate copolymer, is used with respect to 100% by mass of the propylene-based resin. It is preferable to use 3 to 25% by mass in combination.

<< Filler >>
The base material can contain a filler. The filler easily forms pores in the base material, which makes it easy to adjust the whiteness of the recording paper.

Examples of the filler that can be used for the base material include an inorganic filler and an organic filler.
Examples of the inorganic filler include calcium carbonate, calcined clay, silica, diatomaceous earth, talc, barium sulfate, aluminum sulfate, magnesium oxide, alumina, and an ultraviolet absorbing filler. Examples of the ultraviolet absorbing filler include titanium dioxide, zinc oxide and the like.

Examples of the organic filler include polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6, cyclic olefin polymer, or cyclic olefin and ethylene when the thermoplastic resin of the base material is a polyolefin resin. Examples thereof include resins having a melting point higher than the melting point of the polyolefin resin used, for example, in the range of 120 to 300 ° C., or a glass transition temperature in the range of, for example, 120 to 280 ° C.

One of the above inorganic fillers or organic fillers may be used alone or in combination of two or more. When two or more kinds are combined, an inorganic filler and an organic filler may be mixed and used.

The average particle size of the filler is preferably 0.01 to 10 μm, more preferably 0.05 to 8 μm. When the average particle size is 10 μm or less, the uniformity of the pores tends to increase. Further, when the average particle size is 0.01 μm or more, predetermined pores tend to be easily obtained.
The average particle size of the filler is the average value of the measured values of 100 particle sizes randomly extracted from the observation area by observing the cut surface of the thermoplastic resin film in the thickness direction with an electron microscope. The particle size is determined from the maximum value (maximum diameter) of the distance between two points on the contour of the particle.

The content of the filler in the base material is preferably 8% by mass or more, more preferably 14% by mass or more, while it is preferably 65% by mass or less, more preferably 50% by mass or less.
When the content of the filler is 8% by mass or more, a sufficient number of pores can be easily obtained, and a desired whiteness or opacity tends to be imparted to the porous film. Further, when the content is 65% by mass or less, the strength of the porous film is easily obtained, and it tends to be difficult to break during stretch molding.

<< Additives >>
The base material may also contain any additive, if desired. Optional additives include, for example, heat stabilizers, UV stabilizers (light stabilizers), dispersants, antioxidants, antioxidants, optical brighteners, UV absorbers, dyes, pigments, lubricants, anti-adhesives. , Anti-blocking agents, or various known additives such as flame retardants. As the heat stabilizer, for example, sterically hindered phenol-based, phosphorus-based, amine-based, or the like can be usually blended in an amount of 0.001 to 1% by mass. As the light stabilizer, for example, a steric hindrance amine type, a benzotriazole type, a benzophenone type and the like can be usually blended in an amount of 0.001 to 1% by mass. As the dispersant, for example, a silane coupling agent, a higher fatty acid such as oleic acid and stearic acid, a metal soap, polyacrylic acid, polymethacrylic acid or a salt thereof and the like can be usually blended in an amount of 0.01 to 4% by mass. As the antistatic agent, for example, a low molecular weight surfactant such as stearic acid monoglyceride or stearyldiethanolamine can be blended in an amount of usually 0.01 to 4% by mass.

The base material may have either a single-layer structure or a multi-layer structure. In the case of a multi-layer structure, the type and blending amount of the material of each layer may be the same or different. For example, when the base material has a three-layer structure of a first surface layer / core layer / second surface layer, the first surface layer has higher adhesion to the coat layer than the core layer, and the second surface layer has a higher adhesion to the coat layer than the core layer. Also, the adhesion to the adhesive layer described later may be high.

The base material may be a non-stretched film or a stretched film. From the viewpoint of increasing the rigidity of the base material, the base material is preferably a stretched film stretched in at least the uniaxial direction, and may be referred to as a stretched film stretched in the biaxial direction (hereinafter, referred to as a biaxially stretched film). ) Is more preferable. Since the biaxially stretched film is stretched in the biaxial direction, it is difficult to stretch when bent, and since it has a high flexural modulus, it is hard to have a bending habit. When the base material has a multilayer structure, a layer of a non-stretched film and a layer of a stretched film can be combined, or stretched films having the same or different number of stretched axes can be combined in each layer, but at least from the above viewpoint. It is preferable that one layer is a stretched film.

<< Surface treatment >>
The base material is preferably surface-treated from the viewpoint of enhancing the adhesion to the adjacent layer of the base material, for example, the coat layer.
Examples of the surface treatment include corona discharge treatment, frame treatment, plasma treatment, glow discharge treatment, ozone treatment, and the like, and these treatments can be combined. Of these, corona discharge treatment or frame treatment is preferable, and corona treatment is more preferable.

The amount of discharge when the corona discharge treatment is carried out is preferably 600 J / m ² (10 W / min / m ² ) or more, and more preferably 1,200 J / m ² (20 W / min / m ² ) or more. .. Further, the discharge amount is preferably ^{12, 000J / m 2 (200W} · min / ^{m 2)} or less, and more preferably not more than 10,800J ^/ m 2 (180W · min / ^{m 2).} The amount of discharge when the frame processing is performed is preferably 8,000 J / m ² or more, and more preferably 20,000 J / m ² or more. The discharge amount is preferably 200,000 J / m ² or less, and more preferably 100,000 J / m ² or less.

<< Thickness >>
The thickness of the base material is preferably 60 μm or more, more preferably 70 μm or more, still more preferably 80 μm or more, from the viewpoint of imparting elasticity suitable for transport to the recording paper. From the viewpoint of ease of bending, the same thickness is preferably 150 μm or less, more preferably 130 μm or less, and even more preferably 120 μm or less.

(Manufacturing method of recording paper)
The method for producing the recording paper of the present invention is not particularly limited, but it can usually be produced by forming a coat layer on at least one surface of the base material.

The base material is usually obtained by film molding of a resin composition containing a thermoplastic resin. When the base material is a porous film, it can be obtained by mixing a thermoplastic resin with other components such as a filler and then molding the film.

The film forming method is not particularly limited, and various known forming methods can be used alone or in combination. Examples of the film forming method include cast molding, calendar molding, rolling molding, inflation molding and the like in which molten resin is extruded into a sheet by a single-layer or multi-layer T-die or I-die connected to a screw-type extruder. .. A film can also be formed by casting or calendering a mixture of a thermoplastic resin and an organic solvent or oil, and then removing the solvent or oil. Examples of the film forming method for a base material having a multilayer structure include a multilayer die method using a feed block or a multi-manifold, an extrusion lamination method using a plurality of dies, and the like, and each method can be combined.

Examples of the stretching method include a longitudinal stretching method using the peripheral speed difference of the roll group, a transverse stretching method using a tenter oven, a sequential biaxial stretching method combining these, a rolling method, and a simultaneous two stretching method using a combination of a tenter oven and a pantograph. Examples thereof include a shaft stretching method or a simultaneous biaxial stretching method using a combination of a tenter oven and a linear motor. Further, a simultaneous biaxial stretching (inflation molding) method in which the molten resin is extruded into a tube shape using a circular die connected to a screw type extruder and then air is blown into the molten resin can also be used. When a substrate having a multilayer structure including a plurality of stretched films is produced, each layer may be individually stretched before being laminated, or may be stretched together after being laminated. Further, the stretched layer may be stretched again after laminating.

When the thermoplastic resin used for the base material is a non-crystalline resin, the stretching temperature at the time of stretching is preferably in the range of the glass transition temperature or higher of the thermoplastic resin. When the thermoplastic resin is a crystalline resin, the stretching temperature must be at least the glass transition point of the non-crystalline portion of the thermoplastic resin and within the range of the melting point of the crystalline portion of the thermoplastic resin. Specifically, a temperature 2 to 60 ° C. lower than the melting point of the thermoplastic resin is preferable.

The stretching speed of the film is not particularly limited, but is preferably in the range of 20 to 350 m / min from the viewpoint of stable stretch molding.
Further, the draw ratio of the film can also be appropriately determined in consideration of the characteristics of the thermoplastic resin used and the like. For example, when a film containing a homopolymer or copolymer of propylene is uniaxially stretched, the draw ratio is usually about 1.2 times or more, preferably 2 times or more, while usually 12 times or less. It is preferably 10 times or less. The draw ratio in the case of biaxial stretching is usually 1.5 times or more, preferably 10 times or more, while it is usually 60 times or less, preferably 50 times or less. ..

When a film containing a polyester resin is uniaxially stretched, the stretch ratio is usually 1.2 times or more, preferably 2 times or more, while usually 10 times or less, preferably 5 times. It is as follows. The draw ratio in the case of biaxial stretching is usually 1.5 times or more, preferably 4 times or more, while usually 20 times or less, preferably 12 times or less.
Within the range of the draw ratio, there is a tendency that stable stretch molding can be performed. Further, even when a resin composition containing a thermoplastic resin and a filler is used, if the stretch ratio is within the range, the desired porosity can be obtained, the opacity can be easily improved, and the film is less likely to break.

The method of forming the coat layer is not particularly limited. For example, a coating layer can be formed by preparing a coating liquid in which various components of the coating layer are dispersed or dissolved in water, applying the coating liquid on a substrate, and drying the coating liquid. For coating, known coating equipment such as air knife coater, gravure coater, blade coater, roll coater, reverse roll coater, bar coater, curtain coater, die slot coater, champlex coater, size press coater, gate roll coater, etc. Alternatively, a bill blade coater or the like can be used.

(Recording label)
The recording label of the present invention has the above-mentioned recording paper and an adhesive layer provided on the surface opposite to the coat layer of the recording paper.
By using the recording paper of the present invention, it is possible to provide a recording label having excellent ink drying property, less gloss ghost and dry down, and excellent water scratch resistance.

FIG. 2 shows a configuration example of the recording label 10 as one embodiment.
As illustrated in FIG. 2, the recording label 10 has the recording paper 1 and the adhesive layer 13 shown in FIG. The adhesive layer 13 is laminated on the surface of the base material 11 of the recording paper 1 opposite to the coat layer 12. When the recording label 10 is printed, the print layer 5 is provided on the coat layer 12.

<Adhesive layer>
Examples of the pressure-sensitive adhesive that can be used for the pressure-sensitive adhesive layer include rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives.
Examples of the rubber-based pressure-sensitive adhesive include a composition obtained by mixing and dissolving an organic solvent such as benzene, toluene, xylene, and hexane in polyisobutylene rubber, butyl rubber, or a mixture thereof, an avietic acid rosin ester, and a terpene-phenol co-weight. Examples thereof include a composition containing a tackifier such as a coalescence or a terpene-inden copolymer. Examples of the acrylic pressure-sensitive adhesive include 2-ethylhexyl acrylate / n-butyl acrylate copolymer and 2-ethylhexyl acrylate / ethyl acrylate / methyl methacrylate copolymer, which have a glass transition point of −20 ° C. or lower. Examples thereof include a composition in which the copolymer is dissolved in an organic solvent, an emulsion adhesive of an acrylic copolymer having the same composition, and the like. Of these, acrylic adhesives are preferable. As the pressure-sensitive adhesive, various types of pressure-sensitive adhesives such as solution type, emulsion type, delayed type, and hot melt type can be used. From the viewpoint of ease of molding, a solution type or an emulsion type is preferable, and a solution type is more preferable.

The adhesive layer can be formed by directly applying the above-mentioned adhesive to the surface of the recording paper and drying it if necessary. Further, as the adhesive layer, the above-mentioned adhesive is applied to the release paper described later, and if necessary, the adhesive layer is dried to once form the adhesive layer, and then the release paper is recorded so that the adhesive layer is in contact with the surface of the recording paper. It can also be formed by laminating on top. The latter method of forming the adhesive layer once is preferable because each layer of the recording paper is not placed at a high temperature when the adhesive layer is dried.

Examples of the coating device that can be used for coating the adhesive include a die coater, a bar coater, a comma coater, a lip coater, a roll coater, a gravure coater, a spray coater, a blade coater, a reverse coater, an air knife coater, and the like. .. Among them, a comma coater or a gravure coater is preferable, and a gravure coater is more preferable, from the viewpoint of coatability. After the pressure-sensitive adhesive is applied by these coating devices, the pressure-sensitive adhesive layer is formed by leveling, smoothing and drying as necessary.

The amount of the pressure-sensitive adhesive applied is not particularly limited, but the solid content after drying is usually 3 to 60 g / m ² , preferably 5 to 40 g / m ² , and more preferably 10 to 30 g / m ^2. Is.

The thickness of the adhesive layer is preferably 10 to 50 μm in the case of an acrylic adhesive, and preferably 80 to 150 μm in the case of a rubber adhesive.

<Release paper>
The recording label of the present invention may have a release paper on the adhesive layer. The release paper facilitates the handling of recording labels.

The release paper is not limited as long as it is a sheet material whose adhesive strength to the adhesive layer is lower than the adhesive strength between the recording paper and the adhesive layer, and any release paper is appropriately selected from the commonly used release papers. Can be used. Examples of the release paper include high-quality paper, pulp paper such as kraft paper, processed paper obtained by calendar-treating the pulp paper, processed paper coated or impregnated with resin on the pulp paper, and processed paper obtained by laminating a resin film on the pulp paper. Examples thereof include glassine paper, coated paper, processed paper obtained by subjecting a resin film to a silicone treatment, and the like. As the release paper, from the viewpoint of adjusting the peelability from the adhesive layer, a processed paper in which the surface in contact with the adhesive layer is treated with silicone is preferably used.

<Print layer>
The printing layer is a layer formed by printing characters, lines, patterns, or the like.
The printing method is not particularly limited, and known printing methods such as gravure printing, offset printing, flexographic printing, sticker printing, and screen printing can be used. The printing layer may also include printing by various printers such as an inkjet method, an electrophotographic method, and a liquid toner method, foil stamping such as hot stamping and cold stamping, transfer foil, and conventionally known decorations such as holograms.

For printing, various inks such as oil-based ink, oxidative polymerization curable ink, ultraviolet curable ink, water-based ink, powder toner, and liquid toner (electro ink) can be used according to the printing method.

The coat layer according to the present invention is an oil-based ink or an ultraviolet curable type because it has excellent adhesion to ink due to the anchoring effect caused by surface irregularities caused by the inorganic filler, and has high solvent absorption and excellent ink drying property. It has high printability for offset printing using ink, oxidative polymerization curable ink, and the like. It has printability not only for offset printing but also for laser printing using liquid toner or powder toner.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In addition, the description of "part", "%", etc. in the Examples means the description of the mass standard unless otherwise specified.

<Preparation of base material>
(I) Propropylene homopolymer (trade name: Novatec PP MA3, manufactured by Japan Polypropylene Corporation) 67 parts by mass, high-density polyethylene resin (trade name: Novatec HD HJ580N, manufactured by Japan Polyethylene Corporation) 10 parts by mass, heavy calcium carbonate particles (Product name: Softon 1800, manufactured by Bihoku Powder Industry Co., Ltd.) 23 parts by mass were mixed to prepare a resin composition a.

(II) Next, the resin composition a was melt-kneaded by an extruder set at 260 ° C. and extruded into a sheet from a die. This sheet was cooled by a cooling roll to obtain an unstretched sheet. This unstretched sheet was heated again to 150 ° C., and then stretched 4.8 times in the sheet flow direction (MD) by utilizing the speed difference between the rolls to obtain a longitudinally uniaxially stretched resin film.

(III) Separately from this, propylene homopolymer (trade name: Novatec PP MA3, manufactured by Japan Polypropylene Corporation) 51.5 parts by mass, high-density polyethylene resin (trade name: Novatec HD HJ580N, manufactured by Japan Polyethylene Corporation) 3. A resin composition b was prepared by mixing 5 parts by mass and 45 parts by mass of heavy calcium carbonate particles (trade name: Softon 1800, manufactured by Bikita Powder Industry Co., Ltd.).

This is melt-kneaded with an extruder set at 250 ° C., extruded into a film shape from a die on one side of the vertically uniaxially stretched film, and laminated to obtain a first surface layer / core layer laminate (b / a). It was.
Further, using another extruder, the resin composition b is melt-kneaded by an extruder set at 250 ° C. and extruded into a film from a die to form a film on the core layer (a) side of the laminate (b / a). Laminated on the surface. As a result, a laminated body (b / a / b) having a three-layer structure of a first surface layer / a core layer / a second surface layer was obtained.

This three-layer structure laminate was guided to a tenter oven, heated to 155 ° C., and then stretched 8 times in the lateral direction using a tenter. Then, it was heat-set (annealed) at 164 ° C., further cooled to 55 ° C., and the ears were slit to obtain a thermoplastic resin film having a thickness of 80 μm as the base material (1).

(Preparation of coating liquid for coat layer)
The coating liquids (A1) to (A18) and (B1) to (B4) for the coat layer were prepared as follows.

Table 1 is a list of materials used in the preparation.

<Coating liquid (A1)>
Light calcium carbonate (trade name: TP-123CS, manufactured by Okutama Kogyo Co., Ltd., primary particle size (D50): 0.2 μm, crystal structure: aragonite) 79.6 parts by mass, polyether-based highly water-soluble as isocyanate-modified polyethylene glycol Molecular (trade name: Melpol F-220, manufactured by Sanyo Kasei Kogyo Co., Ltd.) 0.7 parts by mass, sodium dioctyl sulfosuccinate as a surfactant (trade name: Sanmorin OT-70, manufactured by Sanyo Kasei Kogyo Co., Ltd.) 1.0 parts by mass , 17.9 parts by mass of styrene-acrylic copolymer (trade name: ZE-1425, manufactured by Seikou PMC) as a binder, 0.7 mass of ammonium zirconium carbonate (trade name: AZ coat 5800MT, manufactured by Sannopco) as a cross-linking agent. Part, antifoaming agent (trade name: Bismer FX-10, manufactured by Nissin Chemical Research Institute, ester wax, polyoxylucylene fatty acid ester, polyoxyethylene alkyl ether fatty acid ester and higher alcohol) 0.1 part by mass and water The composition consisting of 55 parts by mass was mixed and stirred to obtain a coating liquid (A1) for a coat layer.

<Coating liquids (A2) to (A9) and (A13) to (A15)>
In the above coating liquid (A1), each coating liquid (A2) to (A9) is the same as the coating liquid (A1) except that the blending amount of each component is changed as shown in Tables 2 and 3. ) And (A13) to (A15) were prepared.

<Coating liquid (A10)>
Light calcium carbonate (trade name: TP-123CS, manufactured by Okutama Kogyo Co., Ltd., primary particle size (D50): 0.2 μm, crystal structure: aragonite) 72.7 parts by mass, kaolin (hydrous aluminum silicate, trade name: kao) Bright 90, manufactured by THIELE KAOLIN CAMPANY, primary particle size (D50): 0.4 μm) 3.8 parts by mass, polyether-based water-soluble polymer as isocyanate-modified polyethylene glycol (trade name: Melpol F-220, Sanyo Chemical Industries, Ltd.) 0.8 parts by mass (manufactured by Kogyo Co., Ltd.), 1.1 parts by mass of sodium dioctyl sulfosuccinate (trade name: Sanmorin OT-70, manufactured by Sanyo Chemical Industries, Ltd.) as a surfactant, styrene-acrylic copolymer (trade name) as a binder : ZE-1425, manufactured by Seikou PMC) 20.7 parts by mass, ammonium carbonate zirconium carbonate (trade name: AZ Coat 5800MT, manufactured by Sannopco) 0.8 parts by mass, defoaming agent (trade name: Bismer FX-) 10. A composition consisting of 0.2 parts by mass and 55 parts by mass of water (containing ester wax, polyoxylucylene fatty acid ester, polyoxyethylene alkyl ether fatty acid ester and higher alcohol) manufactured by Nissin Chemical Laboratory Co., Ltd. is mixed and stirred. A coating liquid (A10) for the coat layer was obtained.

<Coating liquids (A11) and (A12)>
In the above coating liquid (A10), each coating liquid (A11) and (A12) were prepared in the same manner as the coating liquid (A10) except that the blending amount of each component was changed as shown in Table 2. did.

<Coating liquid (A16)>
In the above coating liquid (A2), coating is performed except that 20.7 parts by mass of styrene-butadiene resin (carboxy-modified SBR, trade name: LX407G51, manufactured by Nippon Zeon Corporation) is used instead of styrene-acrylic resin as a binder. Each coating liquid (A16) was prepared in the same manner as the working liquid (A2).

<Coating liquid (A17)>
In the above coating liquid (A2), except that 0.8 parts by mass of polyglycerol polyglycidyl ether (trade name: Denacol EX-521, manufactured by Nagase ChemteX Corporation) was used instead of ammonium carbonate as a cross-linking agent. Each coating liquid (A17) was prepared in the same manner as the coating liquid (A2).

<Coating liquid (A18)>
In the above coating liquid (A2), 20.7 parts by mass of an ethylene-vinyl acetate copolymer (trade name: Sumikaflex S483HQ, manufactured by Sumika Chemtex Co., Ltd.) was used as a binder instead of the styrene-acrylic resin. Prepared the coating liquid (A18) in the same manner as the coating liquid (A2).

<Coating liquid (B1)-(B4)>
In the above coating liquid (A1), each coating liquid (B1) to (B4) was prepared in the same manner as the coating liquid (A1) except that the blending amount of each component was changed as shown in Table 3. did.

(Manufacturing of recording paper)
<Example 1>
A coating liquid (A1) for a coating layer is applied on one side of the base material (1) with a bar coater and then dried to form a coating layer having ^{a solid content of 15 g / m 2 per unit area.} The recording paper of Example 1 was obtained.

<Examples 2 to 17, 21>
In the above-mentioned Example 1, each coating liquid (A1) for the coat layer was changed to each of the coating liquids (A2) to (A18) shown in Tables 2 and 3 in the same manner as in Example 1. Recording sheets of Examples 2 to 17 and 21 were obtained.

<Examples 18 to 20>
The recording sheets of Examples 18 to 20 were obtained in the same manner as in Example 2 except that the solid content per unit area of the coat layer was changed to the solid content shown in Table 3.

<Comparative Examples 1 to 4>
In the above Example 1, each Comparative Example 1 is the same as in Example 1 except that the coating liquid (A1) for the coat layer is changed to each of the coating liquids (B1) to (B4) shown in Table 3. The recording papers of ~ 4 were obtained.

(Evaluation)
Offset printing was performed on the recording papers of each Example and Comparative Example, and the printability was evaluated as follows. The evaluation results are shown in Tables 2 and 3.

<Offset printing>
The recording papers of each of the examples and comparative examples were cut into A2 plates (420 mm × 594 mm), and a design including a design or the like was offset printed on one side. For printing, an offset printing machine (trade name: SM102, manufactured by Heidelberg) and an oxidation polymerization type sheet-fed process ink (trade name: fusion G (ink, indigo, red, yellow), manufactured by DIC) were used. The design was printed in four colors of ink, indigo, red and yellow, and the density of each color was 100%. Specifically, in an environment of a temperature of 23 ° C. and a relative humidity of 50%, 1000 sheets were continuously printed at a speed of 8000 sheets / hour to obtain an offset printed matter.

<Ink drying property>
An uncoated thermoplastic resin film was laminated on the image portion having a density of 400% in which the four colors of the offset printed matter were superimposed. A paper tube (thickness: 5 mm) having a diameter of 30 mm was placed on the paper tube (thickness: 5 mm), a load of 70 kg was applied for 5 seconds, and the area ratio of the ink transfer portion transferred from the image portion to the thermoplastic resin film 120 minutes after printing was determined. The area ratio is the ratio of the area of the ink transfer portion to the area of the image portion. The area ratio was calculated by performing image processing on the surface of the thermoplastic resin film facing the image portion with an image analyzer (manufactured by Nireco Co., Ltd .: Model Luzex IID) and analyzing it.

From the obtained area ratio of the ink transfer portion, the dryness of the ink was evaluated according to the following criteria. The smaller the area ratio, the less the transfer and the higher the drying property of the ink.
⊚: Area ratio is 20% or less and good level 〇: Area ratio is more than 20% but 30% or less, generally good level Δ: Area ratio is more than 30% but 50% or less Practical level ×: Area ratio exceeds 50%, impractical level

<Dry down>
Immediately after printing, the ink density of the image part (ink, indigo, red, yellow: 100% each) of the offset printed matter is measured using a reflection spectrocolorimeter (manufactured by X-Light), and the ink density of each color is averaged. The average ink density of the four colors immediately after printing was calculated. The measured ink density is a density whose reference is the specified density (ink: 1.80, indigo: 1.45, red: 1.35, yellow: 1.00) measured using the same reflection spectrocolorimeter. is there. Further, 24 hours after printing, the ink density at the same location was measured in the same manner as above, and the four-color average ink density 24 hours after printing was calculated.

The drydown was evaluated as follows from the difference between the 4-color average ink density immediately after printing and the 4-color average ink density 24 hours later. The smaller the difference, the less drydown.
⊚: Difference is 0.15 or less and good level ○: Difference is more than 0.15 but 0.20 or less, and generally good level Δ: Difference is more than 0.20 but 0.30 or less Yes, practical level ×: Difference exceeds 0.30, impractical level

<Water resistance>
The offset printed matter was punched into a size of 70 mm × 110 mm, immersed in ion-exchanged water at 23 ° C. for 24 hours, and then the printed matter was taken out of the water. The taken out printed matter was set in a Gakushin dyeing friction fastness tester (trade name "friction tester type II", manufactured by Suga Test Instruments Co., Ltd.). A friction test was conducted in which the printed surface was rubbed 100 times with a white cotton cloth (gold width No. 3) under a load of 215 g in accordance with JIS l0849: 2004 (dyeing fastness test method for friction).

The image part before and after the test was image-processed by an image analyzer (model Luzex IID, manufactured by Nireco Corporation), and the residual ratio of the area of the image part was calculated. From this residual rate, the water scratch resistance was judged according to the following criteria. The higher the residual rate, the higher the water scratch resistance.
⊚: Residual rate is 95% or more and good level ○: Residual rate is 90% or more and less than 95% and generally good level Δ: Residual rate is 70% or more and less than 90% and practical level × : Survival rate is less than 70%, impractical level

<Friction band voltage attenuation>
Using a constant temperature and humidity chamber (model: TBL-3HW6P3A, manufactured by ESPEC), the recording papers of each Example and Comparative Example were adjusted for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The friction band voltage half-life when friction is applied to the coat layer 20 times by the friction sliding device set so as to be parallel to the adjusted recording paper, is determined by the friction band voltage measuring device (model: EST-7). , Intec) was used for measurement.

From the measured half-life, the friction band voltage attenuation was evaluated according to the following criteria. The shorter the half-life, the faster the voltage band decays due to friction.
⊚: Half-life is 30 seconds or less and good level ○: Half-life is more than 30 seconds but 60 seconds or less, and generally good level Δ: Half-life is more than 60 seconds but 90 seconds or less Practical level ×: Half-life exceeds 90 seconds, impractical level

As shown in Tables 2 and 3, the recording papers of Examples 1 to 21 each containing a specific amount of an inorganic filler and an isocyanate-modified polyethylene glycol are excellent in ink drying property. In addition, there is little dry down and it has excellent water and scratch resistance.

On the other hand, according to Comparative Examples 1 to 4, if a specific amount of the inorganic filler or isocyanate-modified polyethylene glycol is not blended, the dryness or water-scratch resistance of the ink may be insufficient, or drydown may occur. I understand.

This application claims priority based on Japanese Patent Application No. 2019-198727, which is a Japanese patent application filed on October 31, 2019, and incorporates all the contents of the Japanese patent application.

1 ... Recording paper, 11 ... Base material, 12 ... Coat layer, 10 ... Recording label, 13 ... Adhesive layer, 5 ... Printing layer

Claims (12)

1. A recording paper having a base material made of a thermoplastic resin film and a coat layer on at least one surface of the base material.
   The coat layer contains an inorganic filler, isocyanate-modified polyethylene glycol and a binder.
   In the coat layer, the content of the inorganic filler is 47 to 83% by mass, and the content of the isocyanate-modified polyethylene glycol is 0.3 to 4.0% by mass.
   Recording sheet.
2. The average primary particle size (D50) of the inorganic filler is 0.03 to 2.00 μm.
   The recording paper according to claim 1.
3. The coat layer contains at least calcium carbonate as the inorganic filler.
   The recording paper according to claim 1 or 2.
4. The coat layer contains calcium carbonate and kaolin as the inorganic filler.
   The content of the calcium carbonate and the kaolin in the coat layer is 97: 3 to 60:40 by mass ratio.
   The recording paper according to any one of claims 1 to 3.
5. The coat layer contains a surfactant.
   The recording paper according to any one of claims 1 to 4.
6. The content of the surfactant in the coat layer is 0.6 to 4.5% by mass.
   The recording paper according to claim 5.
7. The coat layer contains, as the binder, one or more selected from the group consisting of a styrene-butadiene copolymer, a styrene-acrylic copolymer and an ethylene-vinyl acetate copolymer.
   The recording paper according to any one of claims 1 to 6.
8. The coat layer contains one or more cross-linking agents selected from the group consisting of metal-based cross-linking agents, epoxy-based cross-linking agents, epichlorohydrin-based cross-linking agents, and oxazoline-based cross-linking agents.
   The binder is crosslinked by the crosslinker,
   The recording paper according to any one of claims 1 to 7.
9. The content of the binder in the coat layer is 15 to 45% by mass.
   The recording paper according to any one of claims 1 to 8.
10. The solid content per unit area of the coat layer is 7 to 30 g / m ² .
    The recording paper according to any one of claims 1 to 9.
11. The base material is a porous film containing a thermoplastic resin and a filler.
    The recording paper according to any one of claims 1 to 10.
12. The recording paper according to any one of claims 1 to 11 and
    It has an adhesive layer provided on a surface opposite to the coat layer of the recording paper.
    Recording label.
    
    

Images