JP2003291521A - Recording sheet - Google Patents

Abstract

(57) [Problem] To provide a recording sheet suitable for both a dot matrix printer and a thermal transfer printer. SOLUTION: In a recording sheet in which a coating layer containing a pigment and an adhesive is formed on at least one surface of a sheet-like substrate, the coating layer has a pore volume of 3 to 30 ml and a pore volume of 3 to 30 ml. The specific surface area is adjusted to 150 to 1000 m ² / g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet having a recording layer having both dot matrix printer suitability and thermal transfer printer suitability.

[0002]

2. Description of the Related Art Conventionally, bar code printing has been used for product management in label printing for industrial purposes. A dot matrix printer, a thermal transfer printer, etc. are mainly used for the barcode printing and the designation of the product name. In general, the paper used for printing with a dot matrix printer has good ink absorption and drying properties, and in order to obtain good print coloring, the coating layer of the paper contains a pigment with a high oil absorption amount. Has been. In addition, the paper used for printing with a thermal transfer printer is required to have high smoothness on the surface of the coating layer of the paper in order to obtain good printing without line breaks. Therefore, the paper used for printing by the dot matrix printer uses a pigment having a high oil absorption amount, and thus it is difficult to obtain high smoothness. When a coating layer contains a highly oil-absorptive pigment and therefore has a low smoothness for printing by a thermal transfer printer, line breaks occur and it is difficult to obtain satisfactory printing.

In addition, pigments such as kaolin and light calcium carbonate, which easily exhibit high smoothness, are used in the paper used for printing by a thermal transfer printer, and these pigments are used in the coating layer. When the contained paper is printed using a dot matrix printer, the ink absorbency is poor and the print colorability is insufficient. Further, since the ink absorbency of the coating layer is poor, when the printed matter is pasted on a drum containing a chemical, the print density is largely reduced due to the adhesion of the solvent. Therefore, there has been a strong demand for the development of a recording paper which can be used for both a dot matrix printer and a thermal transfer printer and has excellent printing quality.

[0004]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems, that is, it is suitable for use in both a dot matrix printer and a thermal transfer printer and has excellent printing quality. It is intended to provide a recording sheet having layers.

[0005]

The present invention adopts the following constitution in order to achieve the above object. That is, the recording sheet of the present invention has a sheet-shaped substrate and a coating layer formed on at least one surface thereof and containing a pigment and an adhesive as a main component, and the coating layer is Pore volume of 3 to 30 ml per 1 g and 150 to 1000 m ²
It has a pore specific surface area of / g. In the recording sheet of the present invention, the coating amount of the coating layer is preferably ³ to 16 g / m ² . Also,
In the recording sheet of the present invention, the surface smoothness of the coating layer (according to JAPAN TAPPI No. 5) is preferably 300 seconds or more.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION
In order to achieve the object, the coating layer has 3 g / g.
Pore volume of ~ 30 ml and 150-1000 m
² It is necessary to have a pore specific surface area of / g. Also
The coating amount of the coating layer is 3 to 16 g / m. ² Like to be
Good Furthermore, the smoothness of the surface of the coating layer (JAPAN TAPP
I No. 5) is preferably over 300 seconds
Yes.

The pore volume in the coating layer is less than 3 ml,
And / or pore specific surface area of 150 m ² If less than
Printed recording sheet with a dot matrix printer.
When used for printing, the ink absorbency of the coated layer is poor and
Inadequate printing and coloring may not be obtained. Also, the coating layer
The pore volume inside is larger than 30 ml or the pore specific surface area
Is 1000m² / G, the recording sheet obtained
To print with a dot matrix printer
And the ink absorption of this coating layer is good,
On the other hand, it is difficult for the ink to be retained on the surface layer of the coating layer, which is why
Inadequate printing and coloring may not be obtained.

When the coating amount of the coating layer is less than 3 g / m ² ,
The unevenness on the surface of the sheet-shaped substrate may not be sufficiently flattened. On the other hand, the coating amount of the coating layer is 16 g / m ²
When it exceeds the above, the time required for coating becomes long, or the amount of energy increases, the drying property becomes poor, and the operating efficiency may become insufficient, so the manufacturing cost may be too high. There is.

Smoothness of coating layer surface (JAPAN TAPPI No. 5
Is less than 300 seconds, line breaks are likely to occur in printing with a thermal transfer printer, and it is difficult to obtain satisfactory printing. The surface of the coating layer of the recording sheet of the present invention preferably has a smoothness of 300 seconds or more as described above. The surface of the recording layer having the above-mentioned smoothness is effective for improving the properties of ink transferability during offset printing, misdot rate during gravure printing, transferability for thermal transfer printing, and ink transferability for dot matrix printing.

The pigment to be mixed in the coating layer of the recording sheet of the present invention is not particularly limited, but examples thereof include heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, deramie kaolin, talc and sulfuric acid. Calcium, barium sulfate, titanium dioxide, zinc oxide, alumina, magnesium carbonate, magnesium oxide, silica, magnesium aluminosilicate, particulate calcium silicate, particulate magnesium carbonate, particulate light calcium carbonate, spherical light calcium carbonate, white carbon, bentonite , Mineral pigments such as zeolite, sericite, smectite, and hollow type such as polystyrene resin, styrene-acrylic copolymer resin, urea resin, melamine resin, acrylic resin, vinylidene chloride resin, benzoguanamine resin, etc. , Solid type It may be used one or more selected from organic pigments such as through-hole type resin. The blending amount of the pigment can be appropriately set according to the application, but generally, it is preferably 30 to 90% by mass relative to the total mass of the coating layer.

In the recording sheet of the present invention, the coating layer contains an adhesive (binder) together with the pigment. The type of adhesive (binder) is not particularly limited, and a water-soluble and / or water-dispersible polymer compound can be used. Examples of such an adhesive (binder) include cationic starch, amphoteric starch, oxidized starch,
Enzyme-modified starch, thermochemically modified starch, esterified starch, etherified starch and other starches, carboxymethyl cellulose,
Cellulose derivatives such as hydroxyethyl cellulose, natural or semi-synthetic polymer compounds such as gelatin, casein, soybean protein and natural rubber, polydienes such as polyvinyl alcohol, isoprene, neoprene and polybutadiene,
Polyalkenes such as polybutene, polyisobutylene, polypropylene, polyethylene, vinyl halides, vinyl acetate, styrene, (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, methyl vinyl ether, styrene-acryl, etc. Synthetic rubber latex such as polymers and copolymers, styrene-butadiene type, methylmethacrylate-butadiene type, polyurethane type resin, polyester type resin, polyamide type resin,
From the synthetic polymer compounds such as olefin-maleic anhydride resin and melamine resin, one kind or two or more kinds thereof can be appropriately selected and used according to the purpose.
In addition, a cross-linking agent such as a polyamide polyamine-based compound may be appropriately added to the binder, if necessary.

In the recording sheet of the present invention, in the coating liquid used for forming the coating layer, in addition to the pigment, the binder and, if necessary, a crosslinking agent, various auxiliaries are further added if necessary. , For example, surfactants, pH adjusters, viscosity adjusters, softeners, gloss imparting agents, waxes, dispersants, flow modifiers, antistatic agents, stabilizers, antistatic agents, sizing agents,
One or more of a fluorescent whitening agent, a colorant, an ultraviolet absorber, an antifoaming agent, a water resistant agent, a plasticizer, a lubricant, an antiseptic, and a fragrance may be appropriately contained.

The sheet-shaped base material of the recording sheet of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, in the case of using paper, there is no particular limitation on the manufacturing method or kind of pulp used there, and K
Chemical pulp such as P, SGP, RGP, BCTMP,
Mechanical pulp such as CTMP, waste paper pulp such as deinking pulp, or non-wood pulp such as kefna, bamboo, straw, hemp, etc. can be used, and polyamide fiber, polyester fiber, polynosic fiber, etc. can be used together with pulp. One or more types of inorganic fibers such as organic synthetic fibers, glass fibers, ceramic fibers, carbon fibers and the like can be used.

As the pulp used for the sheet-shaped base paper, chlorine-free pulp such as ECF pulp and TCF pulp is preferably used. A filler may be blended in the sheet-shaped substrate paper, if necessary. In this case, the filler is not particularly limited, but various pigments generally used in high-quality paper, for example, kaolin, calcined kaolin, calcium carbonate, calcium sulfate, barium sulfate, titanium dioxide, talc, zinc oxide, alumina, magnesium carbonate. , Mineral oxides such as magnesium oxide, silica, white carbon, bentonite, zeolite, sericite, smectite, and polystyrene resin, urea resin, melamine resin, acrylic resin, vinylidene chloride resin, etc. Hollow particles,
Also, one or more of solid-type and through-hole type organic pigments can be used.

The sheet-shaped substrate of the recording sheet of the present invention is
It may be selected from synthetic resin films or synthetic papers. As the synthetic resin film, polyethylene (PE), ethylene vinyl acetate (EVA), PE-EVA, linear low density PE (LLDPE), high density PE (HDPE), polypropylene (PP), unstretched PP (CPP). , Stretched PP
(OPP), polyvinyl alcohol (PVA), ethylene vinyl alcohol (EVOH), polyvinyl chloride (P
VC), polyvinylidene chloride (PVDC), polystyrene (PS), polyester (PET) and other transparent films, foam type films, and white films obtained by kneading a white pigment into these films can be used. . As synthetic paper, PE, PP, PET, PV
A synthetic paper or the like manufactured based on a material such as C or PS can be used.

Among the above-mentioned synthetic papers for base materials, PP
A synthetic paper (for example, YUPO (trademark, manufactured by YUPO Corporation)) containing a resin and an inorganic filler as main raw materials and obtained by a biaxially stretched film forming method has high durability. It is one of the preferred sheet-like base materials for the recording sheet of the present invention because it has high conformability to adherends required as an adhesive label and curved surface adhesiveness. Examples of the synthetic paper that can be used as the sheet-like base material of the recording sheet of the present invention include YUPO-FPG, YUPO-FGS, YUPO-GFG, YUPO-SGS, YUPO-KPK (all are trademarks), and the like.

A barrier layer and / or an undercoat layer may be provided on each of the above-mentioned papers, films and synthetic papers. Also, a laminated sheet material such as paper / paper composite paper, paper / film composite sheet, film / film composite film, synthetic paper / synthetic paper composite sheet, synthetic paper / paper composite sheet, or synthetic paper / film composite sheet can be used. Good.

In the coating step for forming the coating layer, generally known coating equipment such as blade coater, air knife coater, roll coater, reverse roll coater, bar coater, curtain coater, die slot coater, gravure coater, chan. Plex coater, brush coater, two-roll or metering blade type size press coater, bill blade coater, short dwell coater,
A lip coater, a gate roll coater, or the like is used as appropriate.

In the present invention, the coating layer is formed on one side or both sides of the sheet-like substrate, and if necessary, one or two or more intermediate layers are provided between the surface of the sheet-like substrate and the coating layer. Layers may be provided to form a multi-layer structure. When forming the double-sided coating or multilayer structure, the coating liquids may have the same composition and / or the same coating amount, but they are different from each other. The laminated structure and the coating amount of these may be appropriately adjusted according to the desired quality level of the recording sheet of the present invention.
When a coating layer is provided on one surface of the sheet-shaped substrate, a synthetic resin layer, a coating layer including a pigment and an adhesive, and / or an antistatic layer may be provided on the back surface of the substrate. The recording sheet thus obtained is improved in curl prevention, printability imparting, and / or paper feeding / discharging aptitude. Further, various processing such as adhesion, magnetism, flame retardancy, heat resistance, water resistance, oil resistance and / or slip resistance is applied to the sheet-like base material, especially the back surface of the base paper. It is also possible to add the suitability for use of the recording sheet.

In the recording sheet of the present invention, a desired recording layer coating liquid is applied onto a sheet-shaped substrate and dried, and then the surface of the formed coating layer is subjected to a surface treatment, if necessary. For example, smoothing processing may be performed. When performing this smoothing process, a normal super calender, gross calender,
It is possible to perform smoothing on machine or off machine using a smoothing processing device such as a soft calendar. The form of the pressurizing device in the smoothing treatment, the number of pressurizing nips, the degree of heating, and the like can be appropriately selected according to an ordinary smoothing treatment device.

The recording sheet obtained by the above-mentioned method is used in a field in which both dot matrix printer suitability and thermal transfer printer suitability are required. Also, sheets for gravure printing, sheets for offset printing,
It can also be used as a base material of metal vapor-deposited paper, a label top sheet for smudge proof such as a drum or a can, an ink jet recording type recording sheet, and an electrophotographic recording sheet. After printing, a transparent film may be overlaminated to protect the recording surface.

[0022]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto. In addition, "part" and "%" in an example show "part by mass (solid content)" and "mass%" unless otherwise specified.

Example 1 As a sheet-shaped substrate, a thickness of 80 μm and a density of 0.77 g /
A cm ³ biaxially stretched PP (polypropylene) synthetic paper (trademark: FPG80, manufactured by Yupo Corporation) was used, and a coating liquid having the following composition was applied to one side of the coated liquid at a coating amount of 7 g /
Coating was performed using a bar coater so as to have m ² (dry solid mass) and dried to form a coating layer, and a recording sheet was produced. Composition of coating liquid Pigment: composition; calcined kaolin (trademark: Ansilex 93, manufactured by Engelhard) 70 parts by mass: composition; light calcium carbonate (trademark: TP123CS, manufactured by Okutama Industry Co., Ltd.) 30 parts by mass Binder: composition; water-based Urethane resin (trademark: UX125, manufactured by Asahi Denka Kogyo Co., Ltd.) 50 parts by mass Preparation of coating liquid 70 parts of calcined kaolin (Ansilex 93) and 30 parts of light calcium carbonate (TP123CS) are added to a pigment as a dispersant. 2 parts of sodium acrylate (trade name; Aron A-9, manufactured by Toagosei Co., Ltd.) was added, and this mixture was dispersed in water using a Choles disperser to prepare a pigment slurry. Binder (UX125) to this pigment slurry
50 parts was added and stirred, and water was further added to prepare a coating liquid having a solid content concentration of 20%. [Printing test] The pore volume, pore specific surface area, coating amount and smoothness of the coating layer of the recording sheet thus obtained are shown in Table 1. Using this recording sheet, a dot matrix printer,
And a thermal transfer printer were used for printing, and the performance was evaluated. The results are shown in Tables 1 and 2. These test methods will be described later.

Example 2 A recording sheet was prepared in the same manner as in Example 1. However,
The coating amount of the coating layer was changed to 4 g / m ² (dry solid mass). The obtained recording sheet was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Example 3 A recording sheet was prepared in the same manner as in Example 1. However,
The coating amount of the coating layer was changed to 15.0 g / m ² (dry solid mass). The obtained recording sheet was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Example 4 A recording sheet was prepared in the same manner as in Example 1. However,
The following pulp sheet was used in place of the biaxially oriented PP synthetic paper used as the sheet-shaped substrate in Example 1, and the compounding amounts of the binder and the crosslinking agent were changed as follows. The obtained recording sheet was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2. [Preparation of Pulp Sheet for Sheet-like Base Material] 100 parts of LBKP (freeness (CSF) = 450 ml) pulp slurry was used as an internally added sizing agent for alkenyl succinic anhydride (trade name; Fibran 81K, manufactured by Arakawa Chemical Industry Co., Ltd. ) 0.0
5 parts, cationized starch as a fixing agent (trade name; Cato
F, manufactured by Nippon NSC Co., Ltd.), and 0.7 part of sulfuric acid band.
Add 5 parts and add 1 part of calcium carbonate as a filler.
0 parts were added, and the mixture was diluted with white water to prepare a stock slurry having a pH of 7 and a solid content concentration of 0.8%. This stock slurry is used to make paper using a Fourdrinier paper machine, and the wet paper thus obtained is coated with a size press solution having a concentration of 6% of oxidized starch (trade name; Ace A, manufactured by Oji Corn Starch Co., Ltd.). The amount is 2 g / m ² in terms of dry mass, coated with a size press device, dried, and smoothed by a machine calender to have a smoothness of 50 seconds, and a basis weight of 80 g / m 2.
^A pulp sheet for sheet-like paper base material ² was obtained. "Coating liquid" Pigment: composition; calcined kaolin (trademark: Ansilex 93, manufactured by Engelhard) 70 parts by mass: composition; light calcium carbonate (trademark: TP123CS, manufactured by Okutama Industry Co., Ltd.) 30 parts by mass Binder: composition; water-based Urethane resin (Trademark: UX125, manufactured by Asahi Denka Kogyo Co., Ltd.) 50 parts by mass [Formation of coating layer on sheet-shaped paper substrate] The obtained coating liquid is applied to both sides of the sheet-shaped paper substrate as described above. The liquid to be coated is coated using a bar coater so that the dry mass is 12 g / m ² per side to form a coating layer, which is passed through a pressure nip composed of a metal roll and an elastic roll. , Smoothness,
It was adjusted to 1000 seconds. Basis weight is 104 g / m
^Two recording sheets were obtained. The obtained recording sheet was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Comparative Example 1 A recording sheet was prepared and evaluated in the same manner as in Example 1. However, the composition of the coating liquid was changed as follows. The results are shown in Tables 1 and 2. "Coating liquid" Pigment: Composition; Light calcium carbonate (trademark: Brilliant S-15, manufactured by Shiraishi Calcium Industry Co., Ltd.) 30 parts by mass: Composition; Light calcium carbonate (trademark: TP123CS, manufactured by Okutama Industry Co., Ltd.) 60 parts by mass: Composition Kaolin (trademark: UW-90, manufactured by Engelhard) 10 parts by mass Binder: Composition; Water-based urethane resin (trademark: UX125, manufactured by Asahi Denka Kogyo Co., Ltd.) 50 parts by mass

Comparative Example 2 A recording sheet was prepared and evaluated in the same manner as in Example 1. However, the composition of the coating liquid was changed as follows. The results are shown in Tables 1 and 2. "Coating liquid" Pigment: composition; light calcium carbonate (trademark: Brilliant S-15, manufactured by Shiraishi Calcium Industry Co., Ltd.) 50 parts by mass: composition; silica (trademark: Fineseal X-30, manufactured by Tokuyama Co., Ltd.) 35 parts by mass: Composition: Kaolin (trademark: UW-90, manufactured by Engelhard) 15 parts by mass Binder: Composition: water-based urethane resin (trademark: UX125, manufactured by Asahi Denka Co., Ltd.) 60 parts by mass

Comparative Example 3 A recording sheet was prepared in the same manner as in Example 4. However,
After forming a coating layer on both sides of the sheet-shaped substrate, the sheet was passed through a pressure nip composed of a metal roll and an elastic roll, and the smoothness was adjusted to 200 seconds. The obtained recording sheet was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Evaluation Method [Measurement of Pore Volume and Pore Specific Surface Area of Coating Layer] It was determined by mercury porosimetry using Micrometrics Pore Sizer 9320 (manufactured by Shimadzu Corporation). The sample was sealed with viscose tape (trademark: Cellotape) on the back side of the paper to prevent the influence of the back side. [Measurement of smoothness of recording sheet] The smoothness of the coating layer surface is
JAPAN TAPPI No. It measured based on 5.

[Dot Matrix Printer Test] (Evaluation of Print Quality) PC-PR101 / 63 manufactured by NEC Corporation
Ribbon: PC201G-01 was used to print on the test recording sheet, and the print density and character readability were visually evaluated. The evaluation results are shown in Table 2. A: High print density and excellent readability. ◯: Print density is slightly high and readability is good. Δ: The print density is low, the readability is slightly poor, and there may be a problem in practical use. X: Low print density and poor readability, which is a practical problem.

[Thermal Transfer Printer Test] (Evaluation of print quality) B-30 ribbon manufactured by TEC: TR4
085 (manufactured by Sony Chemical Co., Ltd.) was used to print on a test recording sheet, the printed area was magnified 30 times with an optical microscope, and the degree of dot omission and bleeding was visually evaluated according to the following evaluation criteria. ⊚: It is extremely excellent with no missing dots or bleeding. ◯: There is almost no dot omission or bleeding, which is good. Δ: Incomplete due to missing dots and fogging. There is a problem in practical use. X: Lots of dots and lots of bleeding and markedly inferior.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

INDUSTRIAL APPLICABILITY The recording sheet of the present invention can be used both as a dot matrix printer and a thermal transfer printer, and is extremely useful in practice in a field where a recording layer having excellent printing quality is required. .

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuya Tanaka             Made by Oji 1-10-6 Shinonome, Koto-ku, Tokyo             Paper Co., Ltd. Shinonome Research Center F-term (reference) 2C056 EA04 FC06                 2H086 DA01                 2H111 CA03 CA14 CA30 CA41

Claims (3)

[Claims] 1. A sheet-like base material, and a coating layer formed on at least one surface thereof and containing a pigment and an adhesive as a main component, wherein the coating layer has 3 to 30 ml per 1 g thereof. And a pore specific surface area of 150 to 1000 m ² / g. 2. The coating amount of the coating layer is 3 to 16 g / m ^2.
The recording sheet according to claim 1, wherein 3. The surface smoothness of the coating layer (JAPAN TAPP
The recording sheet according to claim 1 or 2, wherein I No. 5) is 300 seconds or more.