JPH11300898A - Label paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a label paper which can reduce curling amount after printing using a heat-roll fixing electrophotographic printer and achieve good passableness by printing using the heat-roll fixing electrophotographic printer by selecting a thermoplastic resin film base having 2% or lower shrinkage factor at 130 deg.C in 30 min. for the label paper. SOLUTION: A self-adhesive layer and a release paper are sequentially provided on one side of a base composed of a thermoplastic resin film. A heat shrinkage factor of the base at 130 deg.C in 30 min. is 2% or lower. Thereby, a label paper having suitability for a heat-roll fixing electrophotographic printer, specially excellent curling after printing can be obtained by using a polyolefin, specially a polypropylene film base for the label paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label paper based on a thermoplastic resin film which can be used in a heat roll fixing type electrophotographic printer. The label paper obtained by the present invention has excellent strength and water resistance as compared with plain paper labels, and therefore, a label for an outdoor advertising sticker or a frozen food container label, or a name for an industrial product (how to use,
It is useful as a paper for a label with a note.

[0002]

2. Description of the Related Art Conventionally, as a sticker for outdoor advertising stickers or containers for frozen foods, coated paper used as the sticker or label paper has poor water resistance, so that a thermoplastic resin having good water resistance is used. Films, especially polyolefin synthetic papers, are used. Such a resin film is known, and for details thereof,
For example, JP-B-46-40794, JP-B-49-178
No. 2, JP-A-56-11837, JP-A-57-12
No. 642 and JP-A-57-56224. However, such polyolefin-based synthetic paper has a heat roll surface temperature of 140 to 190.
When used as a print label with a heat roll fixing type electrophotographic printer that becomes a high temperature of ℃, shrinkage due to heat is large compared to the release paper to be bonded, the curl generated after printing is large, and it is rolled into a cylindrical shape, There is a problem that it is difficult to peel off when peeling from release paper, and it has been difficult to use it in a heat roll fixing type electrophotographic printer.

[0003]

SUMMARY OF THE INVENTION According to the present invention, a thermal curl generated when used as a print label by a heat roll fixing type electrophotographic printer is smaller than in the past, and the paper does not curl into a cylindrical shape after passing the paper. Another object of the present invention is to provide a label paper that can be easily peeled from release paper.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a heat roll fixing type electronic device is selected by selecting a thermoplastic resin film substrate (i) having a shrinkage ratio of 2% or less at 130 ° C. for 30 minutes as label paper. An object of the present invention is to provide a label paper which has a reduced curl height after printing by a photographic printer and realizes a good paper-passing property by printing with a heat roll fixing type electrophotographic printer.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention uses a thermoplastic film substrate (i) having a small shrinkage rate at 130 ° C. for 30 minutes with an adhesive layer (ii) and a release paper (iii) bonded thereto. Yes, and will be described in detail below. (1) Thermoplastic resin film substrate (i) In the thermoplastic resin film substrate (i) of the present invention, the thermoplastic resin used includes high-density polyethylene,
Ethylene resin such as medium density polyethylene, or polyolefin resin such as propylene resin, polymethyl-
1-pentene, ethylene-cyclic olefin copolymer, nylon-6, nylon-6,6, nylon-6,10,
Polyamide resins such as nylon-6,12, nylon-6, T, polyethylene terephthalate and copolymers thereof,
Examples thereof include thermoplastic polyester resins such as polyethylene naphthalate and aliphatic polyester, and thermoplastic resins such as polycarbonate, atactic polystyrene, syndiotactic polystyrene, and polyphenylene sulfide. These may be used in combination of two or more. Among these, it is preferable to use a polyolefin resin. Further, among the polyolefin resins, a propylene resin is preferable in terms of chemical resistance, cost, and the like.

The propylene resin is mainly composed of propylene homopolymer, polypropylene or propylene having isotactic or syndiotactic properties and various degrees of stereoregularity, and ethylene, butene-1, Hexene-1, heptene-1,4-
A copolymer with an α-olefin such as methylpentene-1 is used. These copolymers may be binary, ternary or quaternary, and may be random copolymers or block copolymers.

The inorganic fine powder used together with the thermoplastic resin for molding the base material (i) includes calcium carbonate, calcined clay, silica, diatomaceous earth, talc, titanium oxide,
Barium sulfate, alumina or the like having an average particle size of 0.01 to 15 μm is used. When the thermoplastic resin film is a polyolefin resin film, as the organic fine powder, polyethylene terephthalate, polybutylene terephthalate, polycarbonate,
Nylon-6, Nylon-6,6, Nylon-6, T,
Those having a melting point (for example, 170 to 300 ° C.) or a glass transition temperature (for example, 170 to 280 ° C.) higher than the melting point of a polyolefin resin such as a cyclic olefin polymer are used.

If necessary, stabilizers, light stabilizers, dispersants, lubricants and the like may be added. As the stabilizer, a sterically hindered phenol-based, phosphorus-based, amine-based stabilizer or the like may be used.
0.01 to 1% by weight, as a light stabilizer, 0.001 to 1% by weight of a sterically hindered amine, a benzotriazole-based or benzophenone-based light stabilizer, a dispersant of inorganic fine powder, for example, a silane coupling agent, olein A higher fatty acid such as an acid or stearic acid, metal soap, polyacrylic acid, polymethacrylic acid or a salt thereof may be blended in an amount of 0.01 to 4% by weight. The thermoplastic resin film forming the base material (i) may have a single-layer structure, a two-layer structure of a base layer and a surface layer, or a three-layer structure in which a surface layer exists on the front and back surfaces of the base layer. Or a multi-layer structure in which another resin film layer is present between the base layer and the surface layer, and those which do not contain inorganic fine powder and / or organic fine powder. But it is good.

When the thermoplastic resin film forming the base material (i) is a single-layer polyolefin resin film and contains an inorganic and / or organic fine powder, the polyolefin resin is usually 40 to 99.5% by weight. %, 60-0.5% by weight of inorganic and / or organic fine powder,
Preferably, it comprises 50 to 97% by weight of a polyolefin resin and 50 to 3% by weight of an inorganic and / or organic fine powder. When the thermoplastic resin film has a multilayer structure and the base layer and the surface layer contain inorganic and / or organic fine powder, the base layer usually has a polyolefin-based resin of 40 to 9
9.5% by weight, inorganic and / or organic fine powder 60-
0.5% by weight, the surface layer is composed of 25 to 100% by weight of polyolefin resin, and 75 to 0% by weight of inorganic and / or organic fine powder. Preferably, the base layer is composed of 50 to 97% by weight of polyolefin resin, And / or 50 to 3% by weight of organic fine powder, the surface layer of which is 30 to 97% by weight of a polyolefin resin, and 70 to 70% of inorganic fine powder.
Consists of 3% by weight.

If the content of the inorganic and / or organic fine powder contained in the base layer having a single-layer structure or a multilayer structure exceeds 60% by weight, the stretched resin film is liable to break at the time of transverse stretching performed after longitudinal stretching. If the amount of the fine inorganic and / or organic powder contained in the surface layer exceeds 75% by weight, the surface strength of the surface layer after the transverse stretching is low, and the surface layer is broken due to mechanical impact during use after recording on a printer. It is not preferable because it becomes easy.

[Formation of Resin Film] The method of forming the thermoplastic resin film for forming the base material (i) is not particularly limited, and various known methods can be used. Cast molding, calender molding, roll molding, inflation molding, extruding molten resin into a sheet using a single-layer or multilayer T-die or I-die, cast molding of a mixture of a thermoplastic resin and an organic solvent or oil, or Removal of a solvent or oil after calender molding, molding from a solution of a thermoplastic resin and removal of the solvent may be mentioned. In the case of stretching, various known methods can be used, and specific examples include longitudinal stretching using a difference in peripheral speed between roll groups, and transverse stretching using a tenter oven.

[Stretching] Various known methods can be used for stretching. As a specific example, in the case of an amorphous resin, the temperature is equal to or higher than the glass transition temperature of the thermoplastic resin used, and in the case of a crystalline resin, It can be carried out in a known temperature range suitable for each thermoplastic resin from the glass transition point temperature of the non-crystalline part to the melting point of the crystalline part or less, and the longitudinal stretching using the peripheral speed difference of the roll group, using a tenter oven Horizontal stretching, rolling,
Simultaneous biaxial stretching using a combination of a tenter oven and a linear motor is exemplified.

The stretching ratio is not particularly limited, and is appropriately selected depending on the purpose and the characteristics of the thermoplastic resin used. For example, when polypropylene or a copolymer thereof is used as the thermoplastic resin, it is about 1.2 to 12 times, preferably 2 to 10 times when stretched in one direction, and in the case of biaxial stretching, 1.5 to 60 times, preferably 1 in area magnification
It is 0 to 50 times. When another thermoplastic resin is used, it is 1.2 to 10 times, preferably 2 to 5 times when stretched in one direction.
It is 5 to 20 times, preferably 4 to 12 times. Further, a heat treatment at a high temperature is performed as necessary.

The stretching temperature is 2 to 60 ° C. lower than the melting point of the thermoplastic resin to be used. When the resin is a propylene homopolymer (melting point: 155 to 167 ° C.), the stretching temperature is 152 to 164.
110 ° C. for high-density polyethylene (melting point 121-134 ° C.), and 104-115 ° C. for polyethylene terephthalate (melting point 246-252 ° C.). The stretching speed is from 20 to 350 m / min.

When the thermoplastic resin film uses a polypropylene homopolymer and includes a transverse stretching step using a tenter oven, a heat setting zone is provided in the latter half, the set temperature is set as high as possible, and the stretched polypropylene Increasing the temperature of the film to the vicinity of its melting temperature at the highest is effective in reducing the heat shrinkage. For this purpose, the set temperature of the heat set zone can be variously selected depending on the line speed of the stretching step, the flow rate and flow rate of the hot air blown in the heat set zone, the structure of the heat set zone, and the like. 158-165 ° C
Range. When the thermoplastic resin film contains an inorganic fine powder or an organic filler, fine cracks are formed on the film surface and fine pores are formed inside the film. The thickness of the stretched thermoplastic resin film is 20 to
It is 350 μm, preferably 35 to 300 μm.

[Formation of Surface Modified Layer] In order to improve the toner adhesion of the thermoplastic resin film forming the base material (i) and to prevent electrification, at least the printing surface or both surfaces of the printer are subjected to a surface treatment to improve the surface modified layer. Is preferably formed. The surface treatment method is a combination of a surface oxidation treatment and a surface treatment agent. As the surface oxidation treatment, a corona discharge treatment, a flame treatment, a plasma treatment, a glow discharge treatment, an ozone treatment and the like generally used for a film are used alone or in combination. Among these, corona treatment and frame treatment are preferable, and the amount of treatment is 600 to 12,000 J / m ² (10 to 10 in case of corona treatment).
200 W · min / m ² ), preferably 1,200 to 9.0
00J / m ² (20~180W · min / m ^2), when the frame processing, 8,000~200,000J / m ^2, preferably 20,000~100,000J / m ² is used. .

[Surface Treatment Agent] The surface treatment agent in the former stage is mainly selected from the following primers and antistatic polymers, and may be used alone or as a mixture of two or more components. From the standpoints of toner adhesion and antistatic properties, a preferred surface treatment agent is a primer or a combination of a primer and an antistatic polymer.

Primers Examples of the primer include polyethyleneimine, alkyl-modified polyethyleneimine having 1 to 12 carbon atoms, poly (ethyleneimine-urea), an ethyleneimine adduct of polyamine polyamide, and an epichlorohydrin adduct of polyamine polyamide. Polyethyleneimine polymer, acrylamide-acrylate copolymer, acrylamide-acrylate-methacrylate copolymer, polyacrylamide derivative, oxazoline group-containing acrylate polymer,
Acrylate-based polymers such as polyacrylates, polyvinylpyrrolidone, polyethylene glycol,
Water-soluble resins such as polyvinyl alcohol and resins, and water-dispersible resins such as polyvinyl acetate, polyurethane, ethylene-vinyl acetate copolymer, polyvinylidene chloride, chlorinated polypropylene, and acrylonitrile-butadiene copolymer are used.

Of these, preferred are polyethyleneimine-based polymers, urethane resins, polyacrylates, etc., more preferred are polyethyleneimine-based polymers, and further preferred are those having a degree of polymerization of 20 to 3,000. Polyethyleneimine, an ethyleneimine adduct of polyamine polyamide, or a modified polyethyleneimine modified with an alkyl halide, alkenyl halide, cycloalkyl halide or benzyl halide group having 1 to 24 carbon atoms.

Antistatic Polymer Examples of the antistatic polymer include cationic, anionic, and amphoteric polymer types. Examples of the cationic type include polymers having a quaternary ammonium salt structure or a phosphonium salt structure, and nitrogen-containing acrylic. Acrylic or methacrylic polymer having nitrogen having a quaternary ammonium salt structure, acrylic or methacrylic polymer having nitrogen having a betaine structure as an amphoteric system, and styrene-maleic anhydride as a cationic system. Polymer or alkali metal salt thereof, alkali metal salt of ethylene-acrylic acid copolymer or ethylene-
Examples thereof include an alkali metal salt of a methacrylic acid copolymer, and an acrylic or methacrylic polymer having nitrogen having a quaternary ammonium salt structure is particularly preferable. The molecular weight of the antistatic polymer can be set at an arbitrary level depending on polymerization conditions such as polymerization temperature, type and amount of polymerization initiator, amount of solvent used, and chain transfer agent. Generally, the molecular weight of the obtained polymer is 1,000 to 1,000,000,
Among them, the range of 1,000 to 500,000 is preferable.

The surface treatment agent at the first stage of the present invention may contain the following optional components as required. Optional Component 1: Crosslinking Agent By adding a crosslinking agent, the coating film strength and water resistance can be further improved. Examples of the crosslinking agent include epoxy compounds such as glycidyl ether and glycidyl ester, epoxy resins, and water-dispersible resins such as isocyanate, oxazoline, formalin, and hydrazide. The amount of the cross-linking agent to be added is usually within a range of 100 parts by weight or less based on 100 parts by weight of the active ingredient excluding the solvent of the surface modifier.

Optional component 2: alkali metal salt or alkaline earth metal salt As the alkali metal salt or alkaline earth metal salt, water-soluble inorganic salts such as sodium carbonate, sodium hydrogencarbonate, potassium carbonate, sodium sulfite, and others Alkaline salts and sodium chloride, sodium sulfate, sodium nitrate, sodium tripolyphosphate, sodium pyrophosphate, ammonium alum and the like. The amount of the optional component is usually the amount of the active ingredient 1 excluding the solvent of the above-mentioned surface modifier.
It is 50 parts by weight or less with respect to 00 parts by weight. Optional component 3: The surface modifier further includes a surfactant,
Defoamers, water-soluble or water-dispersible finely divided powdered substances and other auxiliaries can also be included. The amount of the optional component is usually 20 parts by weight or less based on 100 parts by weight of the active ingredient excluding the solvent for the surface modifier.

[Formation of Surface Treatment Layer] Each component of the above surface treatment layer is used after being dissolved in water or a hydrophilic solvent such as methyl alcohol, ethyl alcohol, or isopropyl alcohol. Usually used. The solution concentration is usually about 0.1 to 20% by weight, preferably about 0.1 to 10% by weight. The coating method is performed by a roll coater, blade coater, bar coater, air knife coater, size press coater, gravure coater, reverse coater, die coater, lip coater, spray coater, etc. After that, excess water and hydrophilic solvent are removed. The coating amount is 0.005 to 5 g / m ² , preferably 0.01 to 5 g / m ² as a solid content after drying.
２2 g / m ² . When the thermoplastic resin film forming the base material (i) is a stretched film, the surface treatment layer may be coated in one step or in multiple steps regardless of before or after longitudinal or transverse stretching.

(Physical Properties of Stretched Film) In the stretched thermoplastic resin film, the base portion has a porosity represented by the following formula of 5 to 60%, preferably 8 to 35%, more preferably 8 to 25%. If it is less than 5%, it is difficult to reduce the weight, and if it is more than 60%, the strength of the label tends to be difficult.

(Equation 2) The density based on JIS P8118-1976 is 0.6
5 to 1.3 g / cm ³ , preferably 0.8 to 1.1 g / cm ³
cm ³ . If it is less than 0.65, difficulties are likely to occur in terms of substrate strength, and if it exceeds 1.3 g / cm ³ , the weight will be large when many sheets are stacked, making it difficult to carry. In addition, opacity 6 based on JIS P8138-1976
It has physical properties of 0% or more and a Beck smoothness of 50 to 25,000 seconds.

The average thermal shrinkage of this film after heating at 130 ° C. for 30 minutes is within 2%, preferably within 1.5%, both in the vertical and horizontal directions. If it exceeds 2%, the curl after passing through the electrophotographic printer in a state of being bonded to the release paper is large, and the paper is more likely to be curved or cylindrical, and is more difficult to peel off than the release paper. This heat shrinkage ratio is determined by cutting the film into a square having a certain size, for example, 100 mm in both length and width, measuring the size in a constant temperature and humidity room at a temperature of 23 ° C. and a relative humidity of 50%. In the same constant temperature and humidity chamber, the mixture is allowed to cool for 1 hour, and its dimensions are measured and calculated by comparison with those before oven heat treatment.

[Formation of Scratch-Improving Layer] A scratch-improving layer comprising an inorganic and / or organic pigment and a binder is provided on the toner receiving surface side of the base material (i) to improve the scratch resistance of the toner after printing. May be. The thickness of the abrasion improving layer is generally 0.1 to 10 μm, preferably 0.2 to 6 μm. [Pressure-sensitive adhesive layer] The type and thickness (coating amount) of the pressure-sensitive adhesive layer (ii) provided on one side of the substrate (i) may vary depending on the type of the adherend, the environment in which it is used, the strength of adhesion, and the like. Choice is possible. A commonly used aqueous or solvent-based pressure-sensitive adhesive can be applied and dried to form a natural rubber-based, synthetic rubber-based, or acrylic-based pressure-sensitive adhesive. It can be used in the form dispersed in water, such as John or emulsion. In order to improve the opacity of the label, an adhesive containing a pigment such as titanium white can be used.

[Formation of Pressure-Sensitive Adhesive Layer] The pressure-sensitive adhesive layer (ii) is formed by applying a solution on the silicon-treated surface of the release paper (iii). Coating is performed by a roll coater, blade coater, bar coater, air knife coater, gravure coater, reverse coater, die coater, lip coater, spray coater, etc. (Ii)
To form In some cases, the pressure-sensitive adhesive layer (ii) can be formed by directly applying the pressure-sensitive adhesive layer (ii) to the substrate (i). The thickness of the pressure-sensitive adhesive layer (ii) can be variously selected depending on the purpose of use of the label, but is usually 2 to 30 μm, preferably 5 to 30 μm.
20 μm.

[Release Paper] Release paper (iii), which is provided with an adhesive layer sandwiched on the substrate (i), is used to improve the releasability from the adhesive layer (ii) when sticking and using label paper. ,
In general, the surface in contact with the pressure-sensitive adhesive layer (ii) is subjected to silicon treatment. As the release paper (iii), generally used general paper can be used, and high-quality paper or kraft paper can be used as it is, or can be calendered, resin-coated or film-laminated, glassine paper, coated paper, plastic film, etc. Those that have been subjected to silicon processing can be used.

(7) Printing Thermoplastic resin film substrate (i) obtained in this manner
Is used as a base material for electrophotographic printing labels, letterpress printing, gravure printing, flexographic printing, solvent-based offset printing, UV-curable offset printing, and roll-type printing in sheet form and roll form. Can also be used. (Curl after printing on electrophotographic printer) The label to which the release paper obtained as described above was bonded was measured at least 2 minutes after printing on the electrophotographic printer measured in a constant temperature and humidity room at 23 ° C. and a relative humidity of 50%. Preferably, the average value of the curl heights at the four corners of A4 size (210 mm × 297 mm) paper measured within 2 minutes to 2 days is within 100 mm, preferably 80 m
m. If it exceeds 100 mm, or if it is rounded into a cylindrical shape, it is difficult to peel it off when it is peeled off from release paper.

[0030]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The raw materials and evaluation methods used in the examples are as follows.
Further, “parts” in the component mixing ratio indicates “parts by weight”. <Example 1> (Thermoplastic resin film substrate) Melt flow rate (M
FR) 3.5 g / 10 min polypropylene blended with 15 wt% of heavy calcium carbonate having an average particle size of 1.3 μm, titanium white 0.7 wt%, and 5 wt% of high density polyethylene having an MFR of 10 g / 10 min. Composition (C ′)
After kneading with an extruder set at 0 ° C., the mixture was extruded into a sheet shape from a T-die connected to an extruder set at 240 ° C., and cooled with a cooling device to obtain a non-stretched sheet.

The composition extruded in the form of a sheet and the composition used for extrusion and lamination described below are based on 100 parts of the total amount of polypropylene and calcium carbonate used, and 3-methyl-2,6- 0.05 parts of di-t-butylphenol, 0.05 parts of Irganox 1010 (trade name, manufactured by Ciba-Gaiky) as a phenolic stabilizer, and Weston 618 (trade name, manufactured by BorgWarner) as a phosphorus-based stabilizer 0.05 part was blended. 14 this sheet
It was heated to a temperature of 2 ° C. and stretched 4.5 times in the machine direction by a longitudinal stretching machine composed of roll groups having different peripheral speeds.

Polypropylene 4 having an MFR of 8 g / 10 min
6% by weight, 4% by weight of maleic acid-modified polypropylene, 5% of high-density polyethylene (MFR 10g / 10min), 44.3% by weight of calcium carbonate having an average particle diameter of 1.3 μm, and 0.7% by weight of titanium white The composition (A ′) was melt-kneaded with an extruder set at 240 ° C., 50% by weight of polypropylene having an MFR of 10 g / 10 min and 45% by weight of calcium carbonate having an average particle size of 1.3 μm,
5% of high-density polyethylene (MFR 10 g / 10 min),
A composition (B ') mixed with 0.7% by weight of titanium white was melt-kneaded by another extruder set at 240 ° C., and the mixture was laminated in a die. As described above, the resin composition of (C ′) is extruded and stretched, and is co-extruded on both sides of a 4.5-fold stretched sheet obtained by stretching to obtain a five-layer laminate (A ′ / B ′ / C ′ / B '/ A').

(Stretching) A five-layer laminate obtained by oxidizing and coating the sheet obtained above was subjected to a tenter oven for 1 hour.
After heating to 57 ° C, the film was stretched 9.4 times in the transverse direction,
Then, it was passed through a heat setting zone (set temperature: 165 ° C.) following the tenter oven, and a 5-layer laminated film having a thickness of 100 μm (thickness of each layer was 5 μm / 20 μm / 50 μm /
20 μm / 5 μm). (Formation of Surface Treatment Layer) Both surfaces of this film were subjected to corona discharge treatment at an applied energy density of 100 W · min / m ² . Then, on both sides of the film, butyl-modified polyethyleneimine, an ethyleneimine adduct of polyamine polyamide, and an alkyl acrylate-based polymer containing a group having a quaternary ammonium salt structure represented by the following general formula in the molecular chain: The coating amount after drying the aqueous solution containing an equal amount mixture of the coalesced using a roll coater is about 0.1 g per side.
/ M ² and dried to form a surface treatment layer.

[0034]

Embedded image

The base material (i) thus obtained was treated with J
The basis weight based on IS P8118-1976 is 82 g /
m ² and density were 1.03 g / cm ³ . Further, this film was cut into single sheets, left in a ventilation oven at 130 ° C. for 30 minutes, and then allowed to cool for 1 hour in a constant temperature and humidity room at a temperature of 23 ° C. and a relative humidity of 50%, and then cooled in a ventilation oven. The dimensions before and after the heat treatment were measured, and the average value of the vertical and horizontal shrinkage was calculated to be 1.3%. [Stacking with pressure-sensitive adhesive and release paper] Solvent-based acrylic pressure-sensitive adhesive was applied to a coated paper with a thickness of 150 μm,
Coating with a comma coater on a silicon-treated surface of a release paper (iii) having a density of 1.2 g / m ³ (hereinafter abbreviated as a coat type) so that the coating amount after drying is 8 g / m ² . It was dried to form a pressure-sensitive adhesive layer (ii), and was bonded to the substrate (i) shown in Example 1 above to obtain a label sheet.

[Evaluation] The obtained label paper was A-4 (2
(10 mm width x 297 mm flow), 23 ° C, relative humidity 5
After leaving it in a 0% constant temperature and humidity room for one day, a commercially available heat roll fixing type electrophotographic printer, laser shot A40
Printing was performed with 4GII (trade name, manufactured by Canon Inc.) using a paper passing method (face-up paper passing) with the printing surface facing upward. After the paper was passed through the printer, the label was left on a flat table at room temperature, and the average of the curl heights at the four corners two minutes after the paper was passed was 76 mm. The print reproducibility was evaluated by visual inspection. If the print reproducibility was equivalent to that printed on PPC pulp paper commercially available for ordinary laser printers, there was no problem (（), the fatness or deformation of the print, Defective (x) if stain, insufficient print density, etc. were noticeable. Example 1 was at a good level. Table 1 shows the evaluation results of Example 1.

<Comparative Example 1> The same operation as in Example 1 was carried out except that Yupo FPG-80 (Oji Yuka Synthetic Paper Co., Ltd .: trade name) was used for the thermoplastic resin film. Label paper was prepared by laminating release paper and evaluated.
The results are shown in Table 1. <Example 2> The same operation as that of Example 1
μm five-layer laminated film substrate (i) (thickness of each layer is 6 μm
/ 24 µm / 60 µm / 24 µm / 6 µm). A label sheet was prepared by performing the same surface treatment as in Example 1 and pasting with an adhesive and release paper, and the evaluation was performed. The results are shown in Table 1.

Example 3 (Thermoplastic resin film substrate) Melt flow rate (M
FR) 3.5 g / 10 min polypropylene mixed with 15 wt% of heavy calcium carbonate having an average particle diameter of 1.3 μm, 8 wt% of high density polyethylene having an MFR of 10 g / 10 min, and 0.7 wt% of titanium white Composition (D ')
The mixture was kneaded with an extruder set at 0 ° C. and extruded into a strand to obtain pellets. The above composition (E ') was applied to the front and back layers from the center layer using a three-layer T-die connected to a center layer extruder set to 240 ° C and a front and back layer extruder also set to 250 ° C. In addition, 12% by weight of calcium carbonate having an average particle diameter of 1.3 μm and 0.7% by weight of titanium white
MFR 4 g / 10 min polypropylene mixed with
It was extruded into a sheet having a layered structure and cooled by a cooling device to obtain an unstretched three-layer laminated sheet (E ′ / D ′ / E ′). This sheet was heated to a temperature of 142 ° C. and stretched 4.5 times in the machine direction by a longitudinal stretching machine including rolls having different peripheral speeds.

(Stretching) The above-mentioned oxidized and coated 5
After heating the layer laminate to 157 ° C. in a tenter oven, it was stretched 9.6 times in the transverse direction, and then a heat setting zone (set temperature: 165 ° C.) following the tenter oven
To obtain a three-layer laminated film substrate (i) having a thickness of 90 μm (thickness of each layer: 7 μm / 76 μm / 7 μm). The obtained thermoplastic resin film was subjected to the same surface treatment as in Example 1 and the bonding of an adhesive and a release paper to prepare a label paper, which was evaluated. The results are shown in Table 1.

[0040]

[Table 1]

[0041]

As described above, according to the present invention, a label paper using a polyolefin-based, particularly polypropylene-based film base material which is suitable for a heat roll fixing type electrophotographic printer and has particularly good curl after printing is provided. I got it.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G09F 3/10 G09F 3/10 B // B29K 23:00 105: 04 105: 16

Claims (9)

[Claims] 1. A pressure-sensitive adhesive layer (ii) and a release paper (iii) are sequentially provided on one side of a substrate (i) made of a thermoplastic resin film, and the substrate (i) is heated at 130 ° C. for 30 minutes. Label paper having a heat shrinkage of 2% or less. 2. An average of curl heights of four corners in two minutes or more after printing on A-4 size (210 mm × 297 mm) paper by a heat roll fixing type electrophotographic printer is 100.
The label paper according to claim 1, which is not more than mm. 3. The method according to claim 1, wherein the base material (i) is a thermoplastic resin
0 wt%, inorganic and / or organic fine powder 65 to 0 w
3. The label sheet according to claim 1, comprising t%. 4. The label sheet according to claim 1, wherein the base material (i) has a porosity represented by the following formula of 5 to 60%. (Equation 1) 5. The label paper according to claim 1, wherein the thermoplastic resin is a polyolefin resin. 6. The label paper according to claim 5, wherein the polyolefin resin is a propylene resin. 7. JIS P8138-19 for base material (i)
The label paper according to any one of claims 1 to 6, wherein the opacity based on No. 76 is 60% to 100%. 8. The label paper according to claim 1, wherein the base material (i) is provided with a surface treatment layer on at least the surface opposite to the pressure-sensitive adhesive layer. 9. The label paper according to claim 1, wherein the base material (i) is provided with an ink receiving layer at least on a surface opposite to the pressure-sensitive adhesive layer.