JP3139507B2 - Record sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet, and more particularly to a recording sheet suitable for use as a slip such as a single sheet or a continuous sheet.

[0002]

2. Description of the Related Art Recording sheets are used for various purposes. For example, in a copy slip, a recording sheet and a recording sheet (usually made of paper) are laminated and the front side of the recording sheet is formed. Type pressure applied to the (receiving layer side),
The required amount of ink is transferred onto the recording sheet in the form of characters or figures from the ink layer provided on the back side of the recording sheet by writing pressure, heat, or the like. As the ink, a hot melt ink is often used. When the base material (support) of such a recording sheet is made of paper, the hot melt ink penetrates well from the paper surface to an appropriate depth, and a desired hot melt ink layer can be formed relatively easily.

[0003] However, in the case of transportation slips such as courier service, since the recording sheet positioned on the surface of the slip is required to have durability and weather resistance, a recording sheet using a plastic film, which is more durable than paper, as a support is required. Sheets are being used. However, although the film support is excellent in durability and weather resistance, the hot melt ink does not penetrate well as it is, and it is difficult to form a desired hot melt ink layer. Therefore, conventionally, various devices have been devised for forming a hot melt ink layer on a film support. The structure of a recording sheet using a conventional film as a support usually employs a layer structure of a receiving layer / film support / hot melt ink receiving layer / hot melt ink layer. The hot-melt ink receiving layer is provided so that the hot-melt ink permeates properly and a desired hot-melt ink layer is formed on the surface of the hot-melt ink, and is coated with a high-ink-receptive polymer resin. Or
It is formed by applying a material containing a roughening substance to the polymer resin. There is also known a method of improving the adhesiveness of a hot melt ink by roughening the surface of the film support itself by sandblasting or the like, or performing corona discharge treatment or the like.

[0004]

However, in the above-mentioned conventional recording sheet, there is a problem that the adhesion of the hot melt ink is not sufficient. for that reason,
In particular, when the handling is rough, the hot melt ink may be unnecessarily transferred to the paper as the recording sheet, causing stains on the paper. Further, since the adhesiveness of the hot melt ink is not high, it is difficult to uniformly form an ink layer having a target thickness, and copy recording on a recording sheet may be unclear.

[0005] The present invention solves the above problems,
Good adhesion of hot melt ink, preventing unnecessary transfer to recording sheet, easy formation of desired hot melt ink layer, accurate and clear copying and recording on recording sheet The purpose is to provide a simple recording sheet.

[0006]

According to the present invention, there is provided a recording sheet according to the present invention, wherein a receiving layer is provided on one side of a film support, a porous layer is provided on the other side, and hot mail is further provided on the porous layer. It is provided with an ink layer.

The material of the film support of the present invention is not particularly limited, and various known plastic films can be used. Typical examples are polyester film (including paper-like polyester film), polycarbonate film, triacetyl cellulose film, cellophane film, polyamide film, polyimide film, polyphenylene sulfide film, polyether imide film, polyether sulfone film, and aromatic. Examples thereof include a polyamide film, a polysulfone film, a polyolefin film and the like. However, it is preferable to use a polyester film, a polycarbonate film, or a polyphenylene sulfide film from the viewpoints of mechanical properties, thermal properties, price, and the like, and a polyester film is particularly preferable.

[0008] Polyester film is a general term for a polymer film having an ester bond as a main bonding chain. Particularly preferred polyesters are polyethylene terephthalate, polyethylene 2,6-naphthalate, and polyethylene α, β-bis (2 -Chlorphenoxy) ethane 4,4'-dicarboxylate, polybutylene terephthalate, etc. Among them, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) may be considered in view of quality, economy and the like. Is most preferred. Known additives in the PET, for example, heat stabilizers, oxidation stabilizers, weather stabilizers, ultraviolet absorbers,
Organic lubricants, pigments, dyes, organic or inorganic fine particles,
Fillers, release agents, antistatic agents, nucleating agents and the like may be blended.

The PET film is unoriented, uniaxially oriented,
Although any of biaxial orientations can be used, a biaxially oriented PET film is preferable because of its excellent mechanical strength. The biaxially oriented PET film is formed by stretching a non-stretched PET sheet or film about 2.5 to 5 times each in so-called biaxial directions of a longitudinal direction and a width direction. It indicates an orientation pattern.

When the PET film has been subjected to a surface treatment by a known method, that is, a film subjected to a corona discharge treatment (in air, nitrogen, carbon dioxide, etc.) or an easy adhesion treatment, the adhesion to the porous layer is obtained. Since water resistance, solvent resistance and the like are improved, they can be more preferably used. Various methods known in the art can be used for the easy adhesion treatment.Acrylic-based, urethane-based and polyester-based various easy-adhesives are applied in the film manufacturing process, or the film after uniaxial or biaxial stretching is applied to the film. Those coated with various types of easy-to-adhesive agents such as described above can be suitably used.

[0011] The thickness of the plastic film as the film support is not particularly limited, and an appropriate thickness can be set in a range of about 1 to 500 µm, for example, depending on the stiffness required for the recording sheet.

The surface roughness and haze of the film support are not particularly limited either. The thickness of the porous layer described later, the adhesive strength required between the porous layer and the film support, the recording strength, etc. A desired value may be appropriately set in consideration of transparency, whiteness, and the like required for the sheet.

In the recording sheet of the present invention, a porous layer is provided on the surface of the film support opposite to the receiving layer. The porous layer referred to in the present invention has a layer structure having a large number of voids inside and on the surface of the layer. It is particularly preferable that the voids are so-called through holes that communicate with the outside in the porous layer from the viewpoint of appropriate permeability of the hot melt ink (which can ensure good adhesion) described below.

In the present invention, the peak pore size in the pore size distribution curve of the pores in the porous layer is 0.06 to 2.0 μm, preferably 0.08 to 1.0 μm, and more preferably 0.10 to 0.10 μm.
０．５0.5 μm. The peak pore size of the pore size distribution curve is 0.
When the thickness is less than 06 μm, the ink absorption amount becomes insufficient.
When the peak pore size in the pore size distribution curve exceeds 2.0 μm, the surface smoothness is reduced, and the clarity of copy recording with ink tends to be insufficient.

It is desirable that the pore area ratio is in the range of 20 to 85%, preferably 30 to 75%, and more preferably 35 to 65%. If the pore area ratio is less than 20%, the ink absorption is insufficient. When it exceeds 85%, it is easy to take a form in which holes are partially connected, the amount of ink becomes excessive, the cost increases, and the copy record becomes unclear.

The pores are independent from each other when viewed from the surface of the porous layer, and have roundness r (= b / a,
(a: major axis diameter of the hole, b: minor axis diameter of the hole) of 1 to 5 is particularly preferable because the ink absorption is uniform over the entire surface and there is no unevenness in density. This roundness is an average value of 1000 or more measurement points and is usually determined by an image analyzer.

It is desirable that the distribution of the pore size distribution in the pore size distribution curve is small, that is, the pore size distribution is sharp, and that the pore number distribution is 50% or more, preferably 60% or more of the number of pores.
More preferably, 70% or more is within the peak pore diameter ± 30%.

The center line average roughness of the porous layer in the present invention is preferably 0.5 μm or less, preferably 0.3 μm or less, and more preferably 0.1 μm or less, because the sharpness of copy recording is improved. . If it exceeds 0.5 μm, the copy record tends to be unclear.

In the present invention, the surface of the porous layer has undulations having a height of at least 0.2 μm, preferably at least 0.3 μm, more preferably at least 0.4 μm, at least 5/40 μm, preferably at least 7 / m. 40 μm or more, more preferably 1 μm
It is desirable to have 0/40 μm or more. Height is 0.
If the number of undulations of 2 μm or more is less than 5/40 μm, the ink absorption speed is insufficient, and the workability is reduced.
In addition, insufficient ink absorption is likely to occur.

Further, the waviness index of the surface of the porous layer is 0.0
35 to 0.3 μm, preferably 0.045 to 0.2 μm
m, more preferably 0.055 to 0.13,
It is preferable because the ink absorption speed is improved.

A hot melt ink layer is provided on the porous layer. Hot-melt ink is heated and melted or heated to a certain temperature on a printing machine until printing is applied to the material to be printed, maintaining printability such as fluidity, and cooling after printing or printing at room temperature. The hot-melt ink used in the recording sheet of the present invention is not particularly limited, and a known heat-type copying carbon ink, a transfer-type heat-sensitive ink, and a hot-melt glass are used for forming a strong coating film on a material. Ink and the like can be used. In the case of slips, carbon ink is suitable for transfer recording using a thermal head with a computer or personal computer, and transfer-type thermal ink is suitable, and for transfer to a glass surface, hot-melt glass ink is suitable.

The receiving layer of the present invention is a layer composed of a composition containing a white hidden pay pigment and a polymer resin binder as main components. The layer as the main component refers to a layer which is 50% by weight or more in the receiving layer, and other substances may be appropriately added. In the present invention, such a receiving layer is provided on one surface of the film support.

In the present invention, the polymer resin binder is
Thermoplastic resins, selected from thermosetting resins, resins that are soluble in well-known organic solvents, and those having less hydrophilic groups or hydrophilic components are preferred in terms of water resistance, moisture resistance, etc. of the receiving layer, Specific examples include, for example, acrylic, vinyl, urethane, epoxy, polyester, polypropylene, melamine, carbonate, butyral, etc., and copolymers and mixtures thereof.

In the present invention, the water resistance, solvent resistance,
From the viewpoint of heat resistance, abrasion resistance, mechanical strength, and the like, it is preferable to use a thermosetting resin, and more preferably, a resin which can be crosslinked by using a well-known crosslinking agent. In addition, examples of the organic solvent include, for example, alcohols, carboxylate esters, ketones, aliphatic hydrocarbons, alicyclic or aromatic hydrocarbons, and mixtures thereof, and do not adversely affect coating properties and the like. The choice of one is preferred.

[0025] The white hidden pay pigment referred to in the present invention is an inorganic or organic pigment exhibiting a white receiving layer. Examples of the inorganic pigment include zinc carbonate, zinc oxide, zinc sulfide, and the like.
Talc, carion, 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. Examples of organic pigments include, for example, polystyrene, polymethylstyrene, polymethoxystyrene, polyvinyl chloride, polyethylene, polypropylene, polyvinylidene chloride, polymethacrylate, polymethylmethacrylate, polychloroacrylate, and the like. At least one kind selected from the following is applied, but is not particularly limited. The pigment may be in a hollow porous or non-hollow porous state. Further, the pigment may be subjected to a treatment such as adding a functional group such as glycidyl or methylol group to the surface in order to improve dispersibility in the resin.

The average particle size of the white hidden pay pigment is 0.1 to 25.
μm, preferably in the range of 1.0 to 10 μm, is preferred in terms of handleability, coatability and the like. Further, the content of the white hidden pay pigment in the receiving layer is preferably 0.1 to 70% by weight, more preferably 5 to 50% by weight. Content is 0.
If it is less than 1% by weight, the white concealing payability is sufficient, and if it is 70% by weight or more, the adhesion between the receiving layer and the film base material is liable to decrease.

In the present invention, the adhesion, solvent resistance,
In order to further improve the heat resistance, it is preferable that the receiving layer contains a crosslinking agent.

The cross-linking agent referred to in the present invention is a functional group present in a polymer resin binder, for example, a hydroxyl group,
It is not particularly limited as long as it is a cross-linking agent for performing a cross-linking reaction with a carboxyl group, a glycidyl group, an amide group, etc., and finally as a receiving layer having a three-dimensional network structure. Examples include urea-based, melamine-based, acrylamide-based, and polyamide-based resins, and epoxy compounds, isocyanate compounds, and aziridine compounds.

These crosslinking agents may be used alone or in combination of two or more in some cases. The amount of the cross-linking agent to be added is appropriately selected depending on the type of the cross-linking agent, but is usually preferably 0.01 to 50 parts by weight, more preferably 0.1 to 30 parts by weight, per 100 parts by weight of the solid content of the polymer resin. preferable. Further, it is more preferable to use a crosslinking catalyst in combination with the crosslinking binder because crosslinking proceeds more. Known catalysts such as salts, inorganic substances, organic substances, acid substances, and alkaline substances can be used as the crosslinking catalyst. The amount of the crosslinking catalyst to be added is 0.001 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the solid content of the polymer resin. The polymer resin to which the cross-linking agent is added is cross-linked by heating, ultraviolet rays, electron beams or the like after being applied to the film support, but the heating method is generally used.

The receiving layer constituting the recording sheet of the present invention comprises:
Its smoothness is 2 to 3000 seconds, preferably 10 to 150 seconds.
Desirably, the range is 0 seconds. When the smoothness is out of this range, for example, when printing is performed using a fabric ribbon, the ink permeability does not match, the printing becomes lighter, and the ink tends to remain on the surface of the receiving layer. In the present invention, the hunter whiteness of the receiving layer is 40% or more,
Preferably, it is 60% or more. If the Hunter whiteness is less than 40%, the hidden payability becomes insufficient, and the resolution and sharpness of the type and the like on the surface of the receiving layer are reduced, and reading errors such as in the case of a bar code are liable to occur. The layer thickness of the receiving layer is not particularly limited, but is preferably 0.5 to 50 μm,
Those having a size within the range of from 20 to 20 μm are desirable from the viewpoint of uniform formation of the receiving layer, adhesion and the like. In addition, if necessary, known additives such as an antifoaming agent, a coating improver, a thickener, an antistatic agent, an ultraviolet absorber, and a dye may be added to the receiving layer in an amount that does not impair the effects of the present invention. May be contained.

Next, the method for producing a recording sheet according to the present invention will be described, but is not necessarily limited thereto.

First, the porous layer of the present invention is obtained by mixing a water-dispersible polymer and a specific colloidal silica in a specific range, applying the mixture, and drying. Here, the water-dispersible polymer may be an aqueous dispersion of various polymers. Specific examples include an acrylic polymer, an ester polymer, a urethane polymer, an olefin polymer, a vinylidene chloride polymer,
An aqueous dispersion such as an epoxy polymer, an amide polymer, a modified product thereof, or a copolymer can be used. Use of an acrylic polymer or urethane polymer is preferred because the pore size distribution is sharp and the pore area is large, and an acrylic polymer is particularly preferred in view of the mechanical stability of the coating film and the strength of the coating film.

The polymer used in the present invention is preferably dispersed in water and has a particle shape. When the particles do not have a particle shape, that is, a polymer dissolved in a water-soluble polymer, an organic solvent, or the like, it is difficult to make the particles porous.
The particles are preferably dispersed in primary particles, but need not necessarily be dispersed in primary particles, and may include secondary aggregated particles.

The acrylic polymer suitable as the porous layer-forming polymer of the present invention is at least 40 mol% or more of an acrylic monomer, and / or a methacrylic monomer and their ester-forming monomer, and an acrylic monomer having various functional groups such as acrylic. Acid, methacrylic acid,
Alkyl acrylate, alkyl methacrylate (the alkyl group is a methyl group, an ethyl group, an n-propyl group,
Isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, lauryl, stearyl, cyclohexyl, phenyl, benzyl, etc.), and 2-hydroxyethyl acrylate,
Hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, hydroxy-containing monomers such as 2-hydroxypropyl methacrylate, acrylamide,
Amide group-containing monomers such as methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylol methacrylamide, N-methylolacrylamide, N, N-dimethylolacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide , N, N-diethylaminoethyl methacrylate, N, N-diethylaminoethyl acrylate, etc., amino group monomers, glycidyl acrylate, epoxy group-containing monomers such as glycidyl methacrylate, acrylic acid, methacrylic acid salts (sodium salt, potassium salt, ammonium salt) And the like, and these can be used in combination with various monomers. Examples of the various monomers include monomers containing an epoxy group such as allyl glycidyl ether, sulfonic acid groups such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) or salts thereof. A monomer containing a carboxyl group or a salt thereof, such as crotonic acid, itaconic acid, maleic acid, fumaric acid, and salts thereof, a monomer containing an acid anhydride such as maleic anhydride, itaconic anhydride, vinyl isocyanate, allyl isocyanate , Styrene, vinyl methyl ether, vinyl ethyl ether, vinyl trisalkoxysilane, alkyl maleate monoester, alkyl fumarate monoester, acrylonitrile, methacrylonitrile, alkyl itaconate monoester, salt Vinyl, vinyl acetate, vinylidene chloride and the like. The above-mentioned monomers are copolymerized using one kind or two or more kinds.

The above water-dispersible polymer water dispersion 20 to 20
As the colloidal silica mixed with 90 parts by weight, the following silica is suitable for causing undulation in the porous layer. That is, those having a long chain structure in which spherical colloidal silicas are connected in a bead shape (a shape in which a plurality of spherical colloidal silicas are connected in a chain), and those in which the connected silica is branched and / or bent are used. In this case, a porous film having a undulating structure on the surface can be obtained. The above-mentioned colloidal silica is obtained by connecting primary particles of spherical silica with a metal ion having a valence of 2 or more and connecting the particles to each other, and connecting at least 3 or more, preferably 5 or more, and more preferably 7 or more. And further includes those in which beads connected in a bead shape are branched and / or bent.

Also, colloidal silica and other inorganic particles,
For example, it may be a composite or mixed particle with alumina, ceria, titania, or the like, or may be a particle in which these are interposed. The metal ion to be interposed is preferably a divalent or higher valent metal ion, for example, Ca ²⁺ , Zn ²⁺ , M
g ²⁺ , Ba ²⁺ , Al ³⁺ , Ti ⁴⁺ and the like. Especially Ca ²⁺
In the case of the above, it is suitable for producing colloidal silica linked and branched in a bead shape. The primary particle size of the colloidal silica is from 5 nm to 100 nm, preferably from 7 nm to
When the thickness is 50 nm, more preferably 8 nm to 30 nm, it is preferable in terms of increasing the pore forming property and the pore area ratio. Further, the undulation of the porous layer is manifested when the silica particles are linked and branched in a rosary, and it is preferable that the number of linked primary particles of the silica is large, but usually 3 or more and less than 100, preferably 5 or more and less than 50, more preferably 7
It is desirable that the number is at least 30 and less than 30. When the number is two or less, the expression of undulation is insufficient, and when the number is 100 or more, the content of the beads in the porous coating film of the beads linked and / or branched is 3 to 80 parts by weight, preferably 10-7
0 parts by weight, more preferably 20 to 60 parts by weight. If the content is less than 3 parts by weight, there is no porosity formation and no undulation is exhibited, so that the ink absorption rate tends to be slow. If the content is more than 80 parts by weight, the porous formability is reduced, the pore size is reduced, the pore area ratio is reduced, the ink absorption rate is reduced, and the coating film strength is inferior. Defects such as dust at the time are easily generated.

The porosity varies depending on the ratio of the average particle diameter of the water-dispersible polymer and the colloidal silica. The average particle diameter of the colloidal silica must be smaller than the average particle diameter of the water-dispersible polymer. Cannot be made porous. In the case of the colloidal silica linked in a rosary, the length in the minor axis direction of the connected particles observed by an electron microscope is defined as the particle diameter, and the average value of 100 measured lengths is defined as the average particle diameter.

The average particle size ratio of the water-dispersible polymer / colloidal silica is 2/1 to 1000/1, preferably 5/1.
It is particularly preferably from 500/1, more preferably from 10/1 to 200/1 from the viewpoint of the pore formability of the porous layer. In particular an average particle size ratio in relation to an average particle size of colloidal silica and (a ₁₎ and the average particle size of the water-dispersible polymer (a ₂₎ is in the above range, and complete one surface water-dispersible polymer particles The minimum number of particles of colloidal silica required for coating on the surface is α [α = 2π (a ₁ + a ₂ ) ² / (3 ^1/2 ·
when the a ₁ ^2)], water-dispersible polymer particles per range 0.3Arufa～10arufa, preferably 0.5α~6
α, more preferably 0.7% to 3α, is preferable because the effects of the present invention are more remarkably exhibited.

As a coating method, any known method such as a gravure coat, a reverse coat, a bar coat, a kiss coat, and a die coat can be used.

Although the thickness of the porous layer is not particularly limited, it is generally 0.1 to 50 μm, preferably 1 to 30 μm, and more preferably about 3 to 20 μm. If the thickness is too thin, the absorption performance of the hot melt ink is insufficient, and if it is too thick, the strength of the coating tends to be insufficient.

A layer of the hot melt ink as described above is formed on the porous layer of the surface porous film thus obtained, and a receptor layer as described above is provided on the surface on the side opposite to the porous layer. The method for forming the hot melt ink layer is not particularly limited, and a known method can be used.

[0042]

According to the recording sheet of the present invention, a receiving layer is provided on one side of a film support, a porous layer is provided on the other side, and a hot melt ink layer is provided on the porous layer. As a result, the following excellent effects were obtained.

First, since the recording sheet of the present invention is excellent in the adhesiveness and abrasion resistance of the hot melt ink layer, the hot melt ink layer can be easily formed into a desired layer, and the copy record is clear and easy to see.

Further, since the recording sheet of the present invention has excellent adhesiveness of the hot melt ink layer, it has excellent handleability in post-processing.

Further, the receiving layer of the recording sheet of the present invention comprises a fabric ribbon, an electrophotographic toner, an oil-based ink,
Excellent printability with various inks such as V ink.

Since the recording sheet of the present invention has the above-mentioned excellent characteristics, it can be applied to various uses for which copying and recording is required. It is suitable.

[Measurement and Evaluation Methods] The characteristic values in the present invention are based on the following measurement methods and evaluation criteria. (1) Pore size distribution curve Mark the pores in the electron micrograph taken at 10,000 times and perform image processing using a QUAnt: met-720 type image analyzer (manufactured by Image Analyzing Computer Co., Ltd.). When converted to a perfect circle, the area between the minimum pore diameter and the maximum pore diameter was divided in units of 10 μm, and the number of holes in each division was measured. From this measured value, a pore diameter distribution curve was drawn with the vertical axis being the number of holes per unit area and the horizontal axis being the pore diameter, and the pore diameter at the peak was determined.

(2) Pore area ratio The area occupied by pores per unit area was calculated from the above pore diameter distribution curve by the following equation (1).

[0049]

(Equation 1)

In the above equation 1, the symbols are as follows. a _i: average pore diameter n _i in each of the divided portions when the pore diameter in the measuring area was partitioned 10mμ Unit: number of holes in each of the divided portions when the pore diameter in the measuring area was partitioned 10mμ Unit A: Measurement area

(3) Center Line Average Roughness The cut-off of the center line average roughness is in accordance with JIS-B-0601-1976.
Measured at 25 mm.

(4) Wave height, wave number, and wave index Scanning electron microscope ESM-32 with cross section measuring device PMS-1
The surface irregularities observed at 3000 × magnification were measured using a 00 (manufactured by Elionix Inc.), and the nearest valley and valley of the peak having a height of 0.2 μm or more from the surface roughness curve were measured. When the portions were connected by a straight line, the number of the peaks in the measurement length of 40 μm was measured, and the number was set to the number of undulations having a undulation height of 0.2 μm or more. In addition, the cutoff 10
Center line average roughness in μm (Ra ₁₀ ), cutoff 1
The center line average roughness (Ra ₁ ) in μm was obtained, and the swell index was calculated by the following equation. The undulation index (μm) = Ra ₁₀ −Ra _{1 The} above undulation index and undulation index were average values of 50 measurement points.

(5) Average particle diameter The particle diameter was determined by a light scattering method using a laser using a COULTER, N4 type, submicron particle analyzer (manufactured by Nikkaki Co., Ltd.), and the average value was obtained by 10 measurements. When measurement was not possible by this method, it was determined from a 200,000 magnification electron micrograph.

(6) Average Number of Particles From the average particle diameter a determined as described above and the particle specific gravity ρ determined by the density gradient method, the average number of particles contained in 1 ml of a water dispersion of V wt% is determined by the following equation (2). Was.

[0055]

(Equation 2)

(7) Smoothness Smoothness was measured by an Oken-type air permeability smoothing tester “Model KB15” (Asahi Seiko Co., Ltd.).

(8) Hunter whiteness Using Macbeth 2000 manufactured by Kolmorgen, L
a and b were measured, and Hunter whiteness (W) was calculated by the following formula (measured at 550 nm). W = 100 [(100−L) ² + a ² + b ² ] ^1/2

(9) Recording Property of Receptive Layer Serial printer “PC-PR20” manufactured by NEC Corporation
1U ", and the character pattern is changed to the fabric ribbon" O
AR-NF-2 "(manufactured by Pilot Co., Ltd.), and the print quality and ink absorbency were evaluated, and the recordability was determined as follows.The print quality was evaluated by visual observation and the ink absorption was evaluated. Immediately after printing, the character pattern was rubbed back and forth five times with a finger, and evaluated based on the degree of contamination of the receiving layer with the ink: O: Both print quality and ink absorbency were good Δ: Print quality and ink absorbency were slightly inferior. ×: Both printing quality and ink absorbency are poor

(10) Ink Adhesion [I] Cellotape: CT-24 (Nichiban Co., Ltd.) on the ink layer
Was adhered and pressed back and forth 5 times with a load of 2 kg using a hand roller. Then, the cellophane tape was forcibly peeled by hand in the 180 ° direction, and the degree of peeling of the ink layer was observed and evaluated. The criteria were: ：: good (peeling area less than 5%), Δ: slightly poor (peeling area 5% or more and less than 20%), ×: bad (peeling area 20% or more).

(11) Ink Adhesion [II] The ink layer was evaluated by a Gakushin type friction fastness test. The number of times of abrasion was set to once and five times, and the ink layer after abrasion was visually observed and determined as follows. Good adhesion: ○, slightly poor adhesion:
Δ, poor adhesion: ×.

[0061]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples. Example 1 A film support had a center line average roughness of 0.053 μm,
The following coating material was applied to one surface of a biaxially stretched polyethylene terephthalate film having a whiteness of 93% and a thickness of 50 μm so that the thickness after drying became 10 μm, and dried at 130 ° C. for 2 minutes to obtain a porous film. The surface coated with the polyethylene terephthalate film was subjected to corona discharge treatment in air. [Coating material composition] 70 parts by weight (solid weight ratio) of acrylic polymer emulsion (methyl methacrylate / ethyl acrylate / acrylic acid (60/35/5% by weight) copolymer) having an average particle diameter of 0.2 μm Beaded colloidal silica (for example, Snowtex U manufactured by Nissan Chemical Co., Ltd.)
P, an average particle diameter of 0.015 μm), 30 parts by weight (solids weight ratio) was diluted with water to obtain a 30% by weight coating material.

Next, on the uncoated surface of the film, toluene / ethyl acetate (mixing ratio: 1: 1) was used as a diluting solvent, and this was added to a heat-crosslinkable acrylic resin “Cotax” LH-613.
(Manufactured by Toray Industries, Inc.) and a white hidden pay pigment having an average particle size of 1.
A uniformly dispersed coating material having a concentration of 25% by weight in which 0 μm of titanium oxide was added at 40% by weight based on the solid content was applied.
After drying at 0 ° C. for 1 minute, a receiving layer having a thickness of 3.0 μm was provided. After setting the thus obtained film on a hot plate set at 125 ± 5 ° C., a hot-melt ink “HTS66S” manufactured by Teikoku Ink Co., Ltd. was applied on the porous layer by using a rubber black bar method. A recording sheet having a thickness of 0.0 μm was prepared. The properties of the recording sheet were as shown in Table 1 and were excellent in ink adhesion.

Comparative Examples 1 and 2 In the coating material for forming the porous layer of Example 1, spherical colloidal silica having an average particle diameter of 0.015 μm (Comparative Example 1) was used in place of the branched beaded colloidal silica. 2
A recording sheet was obtained in the same manner except that spherical colloidal silica having a thickness of μm (Comparative Example 2) was used. As shown in Table 1, in Comparative Examples 1 and 2, the ink adhesion of the recording sheet was inferior due to insufficient properties of the porous layer.

Examples 2 and 3 and Comparative Examples 3 and 4 In the coating material for forming the porous layer of Example 1, the average particle size of the acrylic polymer emulsion and the branched beaded colloidal silica and the mixing ratio of the solid component were changed. Except for the above, a recording sheet was prepared in the same manner. Those having a porous layer within the scope of the present invention (Examples 2 and 3) have excellent ink adhesion,
Those not satisfying the scope of the present invention (Comparative Examples 3 and 4)
It can be seen that the ink adhesion is poor.

Example 4 Based on Example 1, the same polymer resin binder as in Example 1 was used as the receiving layer, and the average particle size was 0.5 as a white hidden pay pigment.
30% by weight of solid titanium oxide and 10% by weight of porous amorphous silica having an average particle size of 4.0 μm.
A recording sheet was obtained in the same manner as in Example 1 using the uniformly dispersed coating material having a concentration of 30% by weight. As shown in Table 1, the properties of the recording sheet were all excellent.

[0066]

[Table 1]

Continuation of the front page (56) References JP-A-60-234880 (JP, A) JP-A-61-197285 (JP, A) JP-A-3-15795 (JP, A) JP-A-4-47487 (JP) JP-A-5-5956 (JP, U) JP-A-56-56565 (JP, U) JP-A-61-186470 (JP, U) JP-A-62-1971 (JP, U) JP 63-136957 (JP, U) JP50-5601 (JP, B1) JP50-14164 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 27/16 B32B 27/20 C09D 11/02 B42D 11/00 B42D 15/00 B42D 15/04

Claims (9)

(57) [Claims] 1. A recording sheet comprising: a receiving layer provided on one side of a film support; a porous layer provided on the other side; and a hot melt ink layer provided on the porous layer. 2. The porous layer has a peak pore size in a pore size distribution curve of 0.06 to 2.0 μm, and the surface of the porous layer has 5/40 μm undulations having a height of 0.2 μm or more.
The recording sheet according to claim 1 having the above. 3. The porous layer has a pore area ratio of 20 to 85%.
The recording sheet according to claim 1, wherein: 4. The undulation index of the surface of the porous layer is 0.0
The recording sheet according to claim 1, wherein the recording sheet has a thickness of 35 to 0.3 μm. 5. The recording sheet according to claim 1, wherein a center line average roughness of the surface of the porous layer is 0.5 μm or less. 6. The recording sheet according to claim 1, wherein the holes in the porous layer are through holes, and the roundness of the holes observed from the surface is in the range of 1 to 5. . 7. The layer according to claim 1, wherein the porous layer is a layer mainly composed of a mixture of a water-dispersible polymer and colloidal silica which is linked and / or branched in a bead shape. Recording sheet. 8. The recording sheet according to claim 1, wherein the receiving layer has a smoothness of 2 to 3000 seconds. 9. The recording sheet according to claim 1, wherein the receiving layer has a Hunter whiteness of 40% or more.