JP6083132B2 - Release paper for adhesive labels - Google Patents

Description

  The present invention relates to a release paper for adhesive labels.

2. Description of the Related Art Conventionally, release paper for pressure-sensitive adhesive labels having a base paper and a release layer has been widely used for industrial, commercial, and home use in the form of labels, seals, stickers, emblems, and the like. As the base paper for the adhesive label release paper, plain paper such as high-quality paper, glossy paper, kraft paper, and glassine paper are used.
Since the glassine paper is excellent in light transmittance, it is widely used as a base paper for a release paper for adhesive labels. However, the glassine paper is made from chemical pulp that has been subjected to a strong beating process, and since it has been subjected to a calendar process, the freeness is 300 ml CSF or less, and the porosity is also extremely low, 20% to 30%. However, there is a problem that disaggregation (recyclability to recycled paper) is inferior to that of plain paper. In addition, the release paper is preferably inexpensive because it is discarded after use of a label or the like, but the glassine paper has a problem that the price is high.

On the other hand, the plain paper is generally superior in disaggregation and cheaper in price than glassine paper, but has a problem that light transmittance (transparency) is inferior. The plain paper has a problem that it cannot be applied directly because the release agent penetrates. In addition, the adhesive label release paper using the plain paper as the base paper is inferior in light transmission, and may not be used in a label printer that detects a label with a light transmission type sensor.
In the light transmission type sensor, as shown in FIG. 1, a label sheet 10 having a gap 2 made of release paper between adjacent labels 1 and 1 is used, and light transmission between the label 1 and the gap 2 is performed. The label position is detected by measuring the rate difference.
As the light transmission type sensor, there are a method in which light passes through the release paper once as shown in FIG. 2, and a method in which light passes through the release paper twice as shown in FIG.
2 performs sensing of the label 1 that does not transmit light by a mechanism in which light from the light projecting unit 3 reaches the light receiving unit 4 through the gap 2 made of release paper. This method is called “normal light transmission method”.
Further, in the method of FIG. 3, the light emitted from the light projecting unit 3 passes through the gap 2 made of release paper, and the transmitted light is reflected by 90 degrees in the prism 5 and further reflected by 90 degrees (a total of 180 degrees reflected). Then, the label 1 that does not transmit light is sensed by a mechanism in which the obtained reflected light passes through the gap 2 made of release paper and reaches the light receiving unit 4 again. This method is called “light transmission method by prism reflection”. In the “light transmission method by prism reflection” in FIG. 3, since the light has to pass through the gap 2 made of the release paper twice, the light only needs to pass through the release paper once. Compared with the “light transmission method”, a higher light transmittance is required for the release paper.

For this reason, it has been proposed to improve the light transmittance by applying a clearing agent to plain paper (see Patent Document 1 and Patent Document 2).
However, when an emulsion resin is used as the clearing agent and the amount of the emulsion resin attached is large, there is a problem that the disaggregation property becomes insufficient. In addition, if the clearing agent is applied in a large amount, the production cost becomes higher than that of the glassine paper. Therefore, in order to provide a release paper that is excellent in light transmittance and is inexpensive, a release paper in which a sealing layer is formed on plain paper and a release agent liquid is applied to the surface of the sealing layer is used. However, there is a problem that coating defects such as pinholes generated during application of the sealing layer liquid and coating defects due to excessive penetration into plain paper are likely to occur.
If there is a coating failure of the sealing layer, the release agent silicone will not be sealed and will penetrate into plain paper, and after the adhesive layer is formed, the adhesive layer will be peeled off from the release layer forming surface of the base paper There is a problem that proper peelability cannot be obtained.
Therefore, for example, in Patent Document 3, the sealing layer and the intermediate layer are laminated, but depending on the air permeability of the plain paper used, the sealing layer is not formed uniformly, resulting in poor coating and intermediate There is a problem that proper releasability cannot be obtained unless a large amount of layer solution is applied.
Further, in Patent Document 4, a composition mainly composed of a water-soluble polymer is applied to a base paper in a plurality of times, but the amount of adhesion increases when laminated, which is not economical and the amount of adhesion alone. There is almost no difference from the case of increasing.

  Patent Document 5 describes that a coating liquid containing an acetylene glycol compound as a surfactant is used for the undercoat layer. This acetylene glycol compound is added to give stability to the curtain film of the coating solution in the curtain coating method. Moreover, in the said patent document 5, the composite latex of a core shell structure is used as a binder of undercoat. Further, in Patent Document 5, since the undercoat layer contains a pigment, the light transmittance is inferior.

  Therefore, it uses plain paper as the base paper, has excellent light transmission, can be suitably used for a label printer that performs label detection with a light transmission type sensor (especially a light transmission type sensor by prism reflection), and has excellent peelability. Therefore, it is desired to provide an inexpensive release paper for adhesive labels.

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention uses plain paper as a base paper, has improved light transmission, can be suitably used for a label printer that performs label detection with a light transmission type sensor, has excellent peelability, and is inexpensive. The object is to provide a release paper.

The release paper for pressure-sensitive adhesive labels of the present invention as a means for solving the above problems comprises a base paper, a sealing layer, and a release layer in this order on the base paper.
The sealing layer contains a water-soluble resin and an acetylene glycol compound,
The light transmittance at a wavelength of 940 nm is 35% or more.

  According to the present invention, the conventional problems can be solved, the object can be achieved, the plain paper is used as the base paper, the light transmission is improved, and the label printer detects the label by the light transmission type sensor. It is possible to provide an inexpensive release paper for pressure-sensitive adhesive labels that can be suitably used in the present invention.

FIG. 1 is a diagram showing an example of an adhesive label sheet for thermal recording. FIG. 2 is a schematic diagram illustrating an example of the principle of a label printer that performs label detection with a light transmission type (ordinary light transmission type) sensor. FIG. 3 is a schematic diagram showing another example of the principle of a label printer that performs label detection using a light transmission type (light transmission type by prism reflection) sensor. FIG. 4 is a diagram illustrating labels used in continuous issuance in the embodiment.

(Releasable paper for adhesive labels)
The release paper for pressure-sensitive adhesive labels of the present invention comprises a base paper, and a sealing layer and a release layer in this order on the base paper, and preferably has an intermediate layer, and if necessary, other It has the layer of.

<Base paper>
There is no restriction | limiting in particular as the shape, a magnitude | size, and a structure as said base paper, According to the objective, it can select suitably. Examples of the shape of the base paper include a sheet shape. There is no restriction | limiting in particular as a magnitude | size of the said base paper, According to the objective, it can select suitably. The structure of the base paper may be a single layer structure or a laminated structure.

The base paper is not particularly limited as long as it includes at least a base paper, and can be appropriately selected according to the purpose. For example, plain paper such as high-quality paper, glossy paper, and kraft paper is preferably used. .
As the plain paper, print information paper is preferable. Examples of the printing information paper include non-coating printing paper, coating printing paper, and fine coating printing paper. Among these, the non-coated printing paper is preferable because the surface is not coated with a pigment or the like and the light transmittance is good, and the high-quality paper is preferable as the non-coated printing paper. Note that wrapping paper can also be used, and examples of the wrapping paper include pure white roll paper and bleached kraft paper.

-Base paper-
The base paper is preferably made from wood pulp having a freeness of 350 ml CSF to 500 ml CSF. Examples of the wood pulp include hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), and hardwood sulfite pulp (LBSP).
For example, a beater or a refiner can be used for beating the pulp.
Various additives can be added to the pulp slurry obtained after beating the pulp (hereinafter sometimes referred to as “pulp stock”), if necessary. The various additives are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include fillers, dry paper strength enhancers, sizing agents, wet paper strength enhancers, fixing agents, pH adjusters, and the like. And other drugs.

The filler is added for the purpose of improving opacity, whiteness, smoothness, ink absorbability and the like. Examples of the filler include calcium carbonate, clay, kaolin, white clay, talc, titanium oxide, diatomaceous earth, barium sulfate, aluminum hydroxide, and magnesium hydroxide.
The content of the filler is preferably 5% by mass to 15% by mass. When the content of the filler exceeds 15% by mass, the opacity of the base paper may increase.
Since the ash content of the base paper is mainly due to a filler, the ash content is preferably 8% by mass or less, and more preferably 3% by mass or less. When the ash content exceeds 8% by mass, the light transmittance may be lowered.
The ash content can be measured, for example, according to JIS P8251: 2003 “Paper, paperboard and pulp-ash content test method—525 ° C. combustion method”.

Examples of the dry paper strength enhancer include cationized starch, cationized polyacrylamide, anionized polyacrylamide, amphoteric polyacrylamide, and carboxy-modified polyvinyl alcohol.
Examples of the sizing agent include compounds containing higher fatty acids such as fatty acid salts, rosin derivatives such as rosin and maleated rosin, paraffin wax, alkyl ketene dimer, alkenyl succinic anhydride (ASA), and epoxidized fatty acid amide. Is mentioned.
Examples of the wet paper strength enhancer include polyamine polyamide epichlorohydrin, melamine resin, urea resin, and epoxidized polyamide resin.
Examples of the fixing agent include polyvalent metal salts such as aluminum sulfate and aluminum chloride, and cationic polymers such as cationized starch.
Examples of the pH adjuster include caustic soda and sodium carbonate.
As said other chemical | medical agent, an antifoamer, dye, a slime control agent, a fluorescent whitening agent, etc. are mentioned, for example.

The air resistance (Oken) of the base paper is preferably 20 seconds or more, more preferably 20 seconds to 1,000 seconds, and still more preferably 50 seconds to 400 seconds. If the air permeability resistance (Oken) is less than 20 seconds, the sealing layer liquid will permeate, and a sufficient sealing effect may not be obtained. If it exceeds 1,000 seconds, the pulp This is not economical because the manufacturing cost increases because the beating time is increased, applied by at least one of on-machine and off-machine, or processed by a super calender.
Here, the air permeability resistance (Oken) of the base paper is measured in accordance with, for example, JIS P8117: 2009 “Paper and paperboard—Air permeability and air resistance resistance test method (intermediate region) —Gurley method”. can do.

The average thickness of the raw paper is not particularly limited and may be appropriately selected depending on the purpose, basis weight, preferably from ^{10g / m 2 ~200g / m 2} , the light transmitting property is lowered when the basis weight is increased Therefore, 20 g / m ^{2 to} 80 g / m ² is more preferable.

<Seamless layer>
The sealing layer contains a water-soluble resin and an acetylene glycol compound, and further contains other components as necessary.

-Water-soluble resin-
The water-soluble resin is not particularly limited as long as it is a resin that dissolves in water, and can be appropriately selected according to the purpose. The water-soluble resin is easy to disaggregate with water and has good recyclability to recycled paper. Moreover, since the water-soluble resin has a better film forming property than the emulsion resin, it has a high sealing effect and can form a uniform film. Therefore, even if the amount of the release agent attached is small, good release characteristics can be obtained.
The water-soluble resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, casein, dextrin, starch, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, acrylic resin, styrene-butadiene Examples thereof include a copolymer (SBR), an ethylene-vinyl chloride copolymer, a methyl methacrylate-butadiene copolymer, an ethylene-vinyl acetate copolymer, and a (meth) acrylic acid ester copolymer. These may be used individually by 1 type and may use 2 or more types together. Among these, polyvinyl alcohol, acrylic resin, and SBR are preferable, and polyvinyl alcohol is particularly preferable because of a wide selection range of the degree of polymerization and a high sealing effect.
As said polyvinyl alcohol, what was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available products include PVA105, PVA102, PVA103, PVA117, PVA124, PVA110, PVA135H (all manufactured by Kuraray Co., Ltd.), Gohsenol NL-05, NM-11, NM-14, N-300, NH- 18, NH-20, NH-26 (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Denkapoval K-02, K-05, K-17E, K-24E (all manufactured by Denki Kagaku Kogyo Co., Ltd.) , Etc.
The polymerization degree of the polyvinyl alcohol in the sealing layer is preferably 300 to 2,000, and more preferably 500 to 1,500. When the degree of polymerization is less than 300, the base paper is likely to penetrate into the base paper, and the film-forming property of the sealing layer may be lowered. When it exceeds 2,000, the base paper is difficult to penetrate into the base paper, and the peeling is performed. The light transmittance of the paper may be reduced.
The degree of saponification of the polyvinyl alcohol is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 98% or more.
The content of the water-soluble resin in the sealing layer is preferably 0.1% by mass to 30% by mass, and more preferably 1% by mass to 20% by mass.

-Acetylene glycol compound-
By adding an acetylene glycol compound to the sealing layer solution, poor coating is improved. Moreover, the sealing layer liquid containing the acetylene glycol compound improves the light transmittance of the release paper by appropriately soaking the water-soluble resin and the acetylene glycol compound into the base paper.

  Examples of the acetylene glycol compound include an acetylene glycol represented by the following general formula A, an ethylene oxide adduct of acetylene glycol represented by the following general formula B, and the like.

<General Formula A>
However, in the general formula A, R ¹ and R ² both represent an alkyl group.

<General formula B>
However, in the general formula B, R ¹ and R ² both represent an alkyl group. m and n are each a positive number of 0.5 to 25, and m + n is 1 to 40.

In the general formulas A and B, R ¹ and R ² represent an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, and the like. Is mentioned.

Examples of the acetylene glycol represented by the general formula A include 2,5,8,11-tetramethyl-6-dodecin-5,8-diol, 5,8-dimethyl-6-dodecyne-5,8- Diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 4,7-dimethyl-5-decyne-4,7-diol, 8-hexadecine-7,10-diol, 7 -Tetradecin-6,9-diol, 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 3,6-diethyl-4-octyne-3,6-diol, 3,6- And dimethyl-4-octyne-3,6-diol, 2,5-dimethyl-3-hexyne-2,5-diol, and the like. These may be used individually by 1 type and may use 2 or more types together.
As an ethylene oxide adduct of acetylene glycol represented by the general formula B, the number of moles of ethylene oxide units added in the acetylene glycol is 0.5 to 25 moles, and the total number is 1 to 40 moles. is there.

  As said acetylene glycol compound, what was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available products include Surfynol 104 series, Surfynol 400 series, Olfine PD series (all manufactured by Nissin Chemical Co., Ltd.), and the like. Among these, Olfin PD series is particularly preferable from the viewpoint of light transmittance.

  0.05 mass%-15 mass% are preferable, as for content in the said sealing layer of the said acetylene glycol compound, 0.1 mass%-10 mass% are more preferable, and 1 mass%-5 mass% are still more preferable. When the content is less than 0.05% by mass, the coating failure of the sealing layer solution may not be improved. When the content exceeds 15% by mass, the sealing layer solution soaks into the base paper too much. As a result, defects may easily occur in the coating process and the drying process. Specifically, when water penetrates into the paper, the strength of the paper is weakened, and when the tension is applied, the paper may be easily cut, wrinkled, or curled.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a pigment, various adjuvants, etc. are mentioned.
Examples of the pigment include inorganic pigments such as kaolin, clay, calcium carbonate, calcined clay (calcined kaolin), titanium oxide and silica; organic pigments such as urea-formalin resin, styrene-methacrylic acid copolymer and polystyrene resin; Etc.
Examples of the various auxiliary agents include surfactants such as sodium dioctyl sulfosuccinate, sodium dodecylbenzene sulfonate, sodium lauryl alcohol sulfate, sodium dialkyl succinate sulfonate, alginates, and fatty acid metal salts. Can be mentioned.

The sealing layer can be formed by applying a sealing layer solution containing a water-soluble resin and an acetylglycol compound and, if necessary, other components onto the base paper.
There is no restriction | limiting in particular as said application | coating method, According to the objective, it can select suitably, For example, a spin coat method, a dip coat method, a kneader coat method, a curtain coat method, a blade coat method etc. are mentioned.

Adhesion amount of the first stopper layer solution is ^{preferably 0.1g / m 2 ~10g / m 2} , from the viewpoint of film formability as moderate penetration and the sealing layer to the base paper, 0.5 g / m ² to 5 g / ^{m 2} is more preferable. If the adhesion amount is less than 0.1 g / m ² , the sealing layer cannot be formed, and sufficient barrier properties may not be obtained. If it exceeds 10 g / m ² , the production cost increases. It is not economical.

<Intermediate layer>
It is preferable to provide an intermediate layer between the sealing layer and the release layer.
By providing the intermediate layer, it is possible to obtain a sealing effect with a small amount of adhesion, compared to providing a sealing layer on the base paper alone.

The intermediate layer contains a water-soluble resin, and further contains other components as necessary.
-Water-soluble resin-
There is no restriction | limiting in particular as said water-soluble resin, It can select suitably from the thing similar to the water-soluble resin in the said sealing layer. Among these, polyvinyl alcohol, an acrylic resin, and a styrene-butadiene copolymer (SBR) are preferable, and polyvinyl alcohol is particularly preferable because the selection range of the degree of polymerization is wide.
The water-soluble resin of the intermediate layer is the same type as the water-soluble resin of the sealing layer, the interlayer adhesion between the intermediate layer and the sealing layer is good, and if the water-soluble resin is a water-soluble resin, It is preferable in that the interlayer adhesion is improved by swelling the resin of the sealing layer. When polyvinyl alcohol is used as the water-soluble resin of the sealing layer, polyvinyl alcohol is used as the water-soluble resin of the intermediate layer. It is preferable.
The polymerization degree of polyvinyl alcohol in the intermediate layer is preferably 1,000 to 2,400. If the degree of polymerization is less than 1,000, the film formability of the intermediate layer may be inferior, and if it exceeds 2,400, the viscosity of the intermediate layer liquid becomes too high, making it difficult to coat and coating defects. May be more likely to occur.

  The content of the water-soluble resin in the intermediate layer is preferably 0.1% by mass to 30% by mass, and more preferably 1% by mass to 20% by mass.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a pigment, various adjuvants, etc. are mentioned.

The said intermediate | middle layer can be formed by apply | coating the intermediate | middle layer liquid containing a water-soluble resin and another component as needed on the said sealing layer.
There is no restriction | limiting in particular as said application | coating method, According to the objective, it can select suitably, For example, a spin coat method, a dip coat method, a kneader coat method, a curtain coat method, a blade coat method etc. are mentioned.
The coating weight of the intermediate ^{layer, 0.1g / m 2 ~5g / m} 2 is preferred. If the adhesion amount is less than 0.1 g / m ² , the intermediate layer cannot be formed, and sufficient barrier properties may not be obtained. If it exceeds 5 g / m ² , sufficient film formability is obtained. However, it is not economical because the manufacturing cost increases.

<Peeling layer>
The release layer contains at least a release agent, and contains a catalyst and, if necessary, other components.

-Release agent-
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, an emulsion type silicone resin, a solvent type silicone resin, a solventless type silicone resin, a fluororesin, an aminoalkyd resin, a polyester resin, Etc. These may be used individually by 1 type and may use 2 or more types together. Among these, solvent-free silicone resins are preferable from the viewpoints of peel strength, safety, pollution, cost, and the like.
When a solvent-type silicone resin is applied as the release agent, a solvent recovery facility is required to cope with environmental problems. In addition, when an emulsion type silicone resin is applied as the release agent, it is necessary to dry water as a solvent, resulting in poor productivity. On the other hand, the solventless silicone resin is preferable from the viewpoint of productivity because it has little influence on the environment and does not use a solvent.

  Examples of the solventless silicone resin include a polyorganosiloxane having an unsaturated bond and a hydrogen polysiloxane, and a type in which both are subjected to addition polymerization and cured. The solventless silicone resin is cured by heating after coating to form a film.

-Catalyst-
There is no restriction | limiting in particular as said catalyst, According to the objective, it can select suitably, For example, a platinum complex etc. are mentioned.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, various additives etc. are mentioned.

The release layer is formed by applying a release layer solution on the sealing layer or the intermediate layer and then curing by heat, electron beam or ultraviolet ray.
The application method of the release layer liquid is not particularly limited and can be appropriately selected depending on the purpose.For example, a bar coater, a direct gravure coater, an offset gravure coater, an air knife coater, a multi-stage roll coater, a spin coat, Examples include dip coating, kneader coating, curtain coating, and blade coating.

In addition, a calendar process can be performed before application | coating of peeling layer liquid for the smoothness and transparency of a surface.
The calendar processing may be at least one of a soft calendar and a super calendar, or at least one of an on-machine and an off-machine.
The calendering conditions are not particularly limited, and can be appropriately changed according to the target level of paper thickness, smoothness, and the like.

As the coating weight of the release layer solution, in solids, preferably from ^{0.05g / m 2 ~3g / m 2} , more preferably ^{0.4g / m 2 ~3g / m 2} , 0.5g / m 2 ~ 2 g / m ² is more preferable. Adhering amount of the release layer is less than 0.05 g / m ^2, may not sufficient peel properties can be obtained, and when it exceeds 3 g / m ^2, too lightly peelable, label during printer transport Peeling may occur.

The release paper for pressure-sensitive adhesive labels of the present invention has a light transmittance of 35% or more at a wavelength of 940 nm, preferably 36% to 40%. If the light transmittance is less than 35%, the light transmittance may be lowered, and the light may not be used in a label printer that performs label detection with a light transmission type sensor using prism reflection. The light transmittance can be measured using, for example, a spectrophotometer.
The release paper for pressure-sensitive adhesive labels of the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, it is used as a release paper for general pressure-sensitive adhesive labels in the form of labels, seals, stickers, patches, etc. it can.

<Adhesive label>
The pressure-sensitive adhesive label used in the present invention has a pressure-sensitive adhesive layer and a label base material in this order on the release layer in the pressure-sensitive adhesive label release paper of the present invention, and further has other layers as necessary. Become.

-Label substrate-
There is no restriction | limiting in particular as said label base material, According to the objective, it can select suitably, For example, papers, a resin film, cloth, a nonwoven fabric, a metal foil etc. are mentioned. These may be used in a single layer or may be used in a stacked manner. Among these, papers and resin films are preferable.
Examples of the paper include cast-coated paper, art paper, coated paper, high-quality paper, vapor-deposited paper, and synthetic paper. Examples of the resin film include various polymer films such as polypropylene, polyethylene, polyethylene terephthalate, and polyvinyl chloride.
On the label base material, for example, a heat-sensitive recording layer mainly composed of a leuco dye and a developer, an ink jet recording layer, a heat-sensitive transfer recording layer, a heat-sensitive sublimation recording layer, and the like can be provided.

-Adhesive layer-
The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive, and further contains other components as necessary.
The pressure-sensitive adhesive is not particularly limited and can be appropriately selected from known pressure-sensitive adhesives according to the purpose. For example, acrylic pressure-sensitive adhesive, styrene-based pressure-sensitive adhesive, vinyl chloride-based pressure-sensitive adhesive, and vinyl acetate-based pressure-sensitive adhesive Examples thereof include pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, polyurethane-based pressure-sensitive adhesives, polyolefin-based pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives. These may be used individually by 1 type and may use 2 or more types together. Among these, acrylic adhesives are particularly preferable.

  There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, A solvent, various additives, etc. are mentioned.

The pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive layer liquid containing a pressure-sensitive adhesive and other components as required on the release layer of the pressure-sensitive adhesive label release paper. In addition, you may apply to the back surface of the said label base material.
Examples of the method for applying the adhesive layer solution include a roll coater, a knife coater, a bar coater, a slot die coater, and a curtain coater.
There is no restriction | limiting in particular in the average thickness of the said adhesive layer, According to the objective, it can select suitably, Usually, 1 micrometer-100 micrometers are preferable.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example at all.
In the following examples and comparative examples, the air resistance and ash content of the high-quality paper as the base paper were measured as follows.

<Air permeability resistance>
The air resistance is measured according to JIS P8117: 2009 “Paper and paperboard—Air permeability and air resistance test method (intermediate region) —Gurley method”. -55, manufactured by Kumagai Riki Kogyo Co., Ltd.).

<Ash content>
The ash is burned in a muffle furnace (SSTS-26K, manufactured by Isuzu Seisakusho Co., Ltd.) in accordance with JIS P8251: 2003 “Paper, paperboard and pulp-ash content test method—525 ° C. combustion method”, and the residue is electronically balanced. (AEU210, manufactured by Shimadzu Corporation).

( Reference Example 1)
<Preparation of release paper>
Mass after drying a sealing layer solution having the following composition on high-quality paper 1 (basis weight 60 g / m ² , air permeability resistance (Oken) 35 seconds, ash content 1% by mass, manufactured by Nippon Paper Industries Co., Ltd.) as a base paper Was applied so as to be ² g / m ² to provide a sealing layer. Next, the sealing layer was subjected to calendar pressurization (pressure 25 kg / cm ² , speed 15 m / min). Next, a release layer solution having the following composition was applied onto the sealing layer after pressing the calendar so that the mass after drying was 1.0 g / m ² to form a release layer. Thus, the release paper of Reference Example 1 was produced.

[Sealing layer solution]
・ Polyvinyl alcohol (degree of polymerization: 500, manufactured by Kuraray Co., Ltd., PVA105) 10 mass% aqueous solution: 100 mass parts: Acetylene glycol compound (manufactured by Nissin Chemical Industry Co., Ltd., Olphine PD-004): 10 mass% aqueous solution: 0.1 parts by mass

[Peeling layer solution]
Solvent-free silicone resin (Toray Dow Corning, SP7015) ... 100 parts by mass Catalyst (Toray Dow Corning, SP7077R) ... 2 parts by mass

<Preparation of pressure-sensitive adhesive label for thermal recording>
Next, an acrylic pressure-sensitive adhesive (manufactured by Seiden Chemical Co., Ltd., AT1202) was applied to the surface of the prepared release paper so that the mass after drying was 20 g / m ² , dried, and heat-sensitive recording paper (stock) It bonded together with the company Ricoh make, thermal paper type 135LA-1). Thus, the pressure-sensitive adhesive label for thermal recording of Reference Example 1 was produced.

( Reference Example 2)
In Reference Example 1, a heat-sensitive recording pressure-sensitive adhesive label was produced in the same manner as in Reference Example 1, except that 0.1 part by mass of the acetylene glycol compound in the sealing layer solution was changed to 2 parts by mass.

( Reference Example 3)
In Reference Example 1, a heat-sensitive recording pressure-sensitive adhesive label was produced in the same manner as in Reference Example 1, except that 0.1 part by mass of the acetylene glycol compound in the sealing layer solution was changed to 8 parts by mass.

( Reference Example 4)
In Reference Example 1, a pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 1 except that 0.1 part by mass of the acetylene glycol compound in the sealing layer solution was changed to 15 parts by mass.

( Reference Example 5)
In Reference Example 1, the polyvinyl alcohol in the sealing layer solution was replaced with 20.8 parts by mass of SBR resin (manufactured by Nippon A & L Co., Ltd., Nalstar SR-102, solid content 48% by mass) and 79.2 parts by mass of water. Except for this, a pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 1.

( Reference Example 6)
Reference Example 1, the polyvinyl alcohol in the sealing layer solution, an acrylic resin (BASF Corporation, Joncryl 734, solid content 42 wt%) was replaced by 23.8 parts by weight, and water 76.2 parts by weight, Reference In the same manner as in Example 1, a thermosensitive recording adhesive label was produced.

( Reference Example 7)
In Reference Example 2, except that the quality paper 1 was replaced with quality paper 2 (basis weight 60 g / m ² , air permeability resistance (Oken) 15 seconds, ash content 12% by mass, manufactured by Hokuetsu Kishu Paper Co., Ltd.) In the same manner as in Reference Example 2, a heat-sensitive recording adhesive label was produced.

( Reference Example 8)
In Reference Example 2, except that the quality paper 1 was replaced with quality paper 3 (basis weight 60 g / m ² , air permeability resistance (Oken) 1,500 seconds, ash content 1% by mass, manufactured by Nippon Paper Industries Co., Ltd.) In the same manner as in Reference Example 2, an adhesive label for thermal recording was produced.

( Reference Example 9)
<Preparation of release paper>
Fine paper 1 (basis weight 60 g / m ² , air permeation resistance (Oken) 35 seconds, ash content 1% by mass, manufactured by Nippon Paper Industries Co., Ltd.), after drying a sealing layer solution having the following composition, the mass is 1 g / m. ^The coating was applied to form a sealing layer.
Next, an intermediate layer solution having the following composition was applied on the sealing layer so that the mass after drying was 1 g / m ² to provide an intermediate layer. Next, the intermediate layer was subjected to calendar pressurization (pressure 25 kg / cm ² , speed 15 m / min). Next, a release layer solution having the following composition was applied onto the intermediate layer subjected to calendar pressure so that the mass after drying was 1.0 g / m ² to form a release layer. Thus, the release paper of Reference Example 9 was produced.

[Sealing layer solution]
・ SBR resin (Nippon A & L Co., Ltd., Nalstar SR-102, solid content: 48 mass%) 20.8 mass parts Water: 79.2 mass parts Acetylene glycol compound (Nisshin Chemical Industry Co., Ltd.) Manufactured by Olfine PD-004) 10% by mass aqueous solution 2 parts by mass

[Intermediate layer liquid]
-SBR resin (NALSTAR SR-102, manufactured by Nippon A & L Co., Ltd.) 48 mass% solid content 20.8 mass parts

[Peeling layer solution]
Solvent-free silicone resin (Toray Dow Corning, SP7015) ... 100 parts by mass Catalyst (Toray Dow Corning, SP7077R) ... 2 parts by mass

<Preparation of pressure-sensitive adhesive label for thermal recording>
Next, an acrylic pressure-sensitive adhesive (manufactured by Seiden Chemical Co., Ltd., AT1202) was applied to the release layer surface of the prepared release paper so that the mass after drying was 8 g / m ² , dried, and heat-sensitive recording paper (Ricoh Co., Ltd., thermal paper type 135LA-1) was attached. Thus, a heat-sensitive recording adhesive label was produced.

( Reference Example 10)
In Reference Example 9, the SBR resin and the water of the sealing layer liquid and the intermediate layer liquid, 23.8 parts by mass of 42% by mass of an acrylic resin (manufactured by BASF, Joncrill 734), and 76.2 parts by mass of water A thermosensitive recording pressure-sensitive adhesive label was produced in the same manner as in Reference Example 9 except that.

( Reference Example 11)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 200, manufactured by Kuraray Co., Ltd., PVA102), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree 1,700, manufactured by Kuraray Co., Ltd., PVA117) 10% by mass aqueous solution was used.

(Example 12)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 300, manufactured by Kuraray Co., Ltd., PVA103), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree 1,700, manufactured by Kuraray Co., Ltd., PVA117) 10% by mass aqueous solution was used.

(Example 13)
In Reference Example 9, the SBR resin and water of the sealing layer solution were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 1,700, manufactured by Kuraray Co., Ltd., PVA117), and the SBR resin and water of the intermediate layer solution were used. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 1,700, manufactured by Kuraray Co., Ltd., PVA117) was used.

(Example 14)
In Reference Example 9, the SBR resin and water of the sealing layer solution were changed to 100 parts by mass of a 10% aqueous solution of polyvinyl alcohol (degree of polymerization 2,400, manufactured by Kuraray Co., Ltd., PVA124), and the SBR resin and water of the intermediate layer solution were added. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 1,700, manufactured by Kuraray Co., Ltd., PVA117) was used.

(Example 15)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 500, manufactured by Kuraray Co., Ltd., PVA105), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree 300, manufactured by Kuraray Co., Ltd., PVA103) 10 mass% aqueous solution was used.

(Example 16)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 500, manufactured by Kuraray Co., Ltd., PVA105), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree: 1,000, manufactured by Kuraray Co., Ltd., PVA110) 10% by mass aqueous solution was used.

(Example 17)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 500, manufactured by Kuraray Co., Ltd., PVA105), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree 1,700, manufactured by Kuraray Co., Ltd., PVA117) 10% by mass aqueous solution was used.

(Example 18)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 500, manufactured by Kuraray Co., Ltd., PVA105), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree 2,400, manufactured by Kuraray Co., Ltd., PVA124) 10% by mass aqueous solution was used.

( Reference Example 19)
In Reference Example 9, the SBR resin and water of the sealing layer liquid were changed to 100 parts by mass of a 10% by weight aqueous solution of polyvinyl alcohol (polymerization degree 500, manufactured by Kuraray Co., Ltd., PVA105), and the SBR resin and water of the intermediate layer liquid were changed to polyvinyl. A pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 9 except that 100 parts by mass of an alcohol (polymerization degree 3,500, manufactured by Kuraray Co., Ltd., PVA135H) 10 mass% aqueous solution was used.

(Example 20)
In Example 17, a heat-sensitive recording pressure-sensitive adhesive label was produced in the same manner as in Example 17 except that Olfin PD-001 manufactured by Nissin Chemical Industry Co., Ltd. was used as the acetylene glycol compound of the sealing layer solution.

(Example 21)
In Example 17, a heat-sensitive recording pressure-sensitive adhesive label was prepared in the same manner as in Example 17 except that Surfynol 104H manufactured by Nissin Chemical Industry Co., Ltd. was used as the acetylene glycol compound of the sealing layer solution.

(Example 22)
In Example 17, a pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Example 17 except that Surfynol 420 manufactured by Nissin Chemical Industry Co., Ltd. was used as the acetylene glycol compound of the sealing layer solution.

( Comparative Reference Example 1)
In Reference Example 1, a pressure-sensitive adhesive label for thermal recording was prepared in the same manner as in Reference Example 1 except that the sealing layer solution was not applied.

(Comparative Example 2)
In Reference Example 1, a pressure-sensitive adhesive label for thermal recording was produced in the same manner as in Reference Example 1 except that the acetylene glycol compound in the sealing layer solution was removed.

(Comparative Example 3)
In Reference Example 1, the same as in Reference Example 1 except that the diacetyl succinate sulfonic acid Na salt (Nippon Emulsifier Co., Ltd., New Coal 290-A) was used as the acetylene glycol compound of the sealing layer solution. An adhesive label was prepared.

(Comparative Example 4)
In Example 12, a pressure-sensitive adhesive label for thermal recording was produced in the same manner as in Example 12 except that the acetylene glycol compound in the sealing layer solution was removed.

(Comparative Example 5)
In Example 12, except that the acetylene glycol compound of the sealing layer solution was dialkyl succinate sulfonic acid Na salt (manufactured by Nippon Emulsifier Co., Ltd., New Coal 290-A), the same as in Example 12, for thermal recording. An adhesive label was prepared.

(Comparative Example 6)
A pressure sensitive adhesive label for thermal recording was produced in the same manner as in Reference Example 1 except that the following sealing layer solution was used in Reference Example 1.
<Seamless layer solution>
Core-shell type acrylic resin (Taisei Fine Chemical Co., Ltd., Acryt UW-550CS, solid content 10% by mass) ... 100 parts by mass Kaolin (Imeris Minerals Japan Co., Ltd., Conzer 1500) ... 10 parts by mass 10% by mass aqueous solution of acetylene glycol compound (manufactured by Nissin Chemical Industry Co., Ltd., Surfynol 104H) 0.2 mass part

Next, the sealing layer liquid and peeling in Reference Examples 1 to 10, 11, 14 , 15, 19, Examples 12 to 13, 16 to 18 , 20 to 22, and Comparative Reference Example 1 and Comparative Examples 2 to 6 With respect to the paper and the heat-sensitive recording pressure-sensitive adhesive label, the coating property, light transmittance, and peeling property of the sealing layer solution were evaluated as follows. The results are shown in Table 2.

<Coating properties of sealing layer solution>
Each prepared sealing layer solution is applied at a speed of 18 m / min with a wire bar to any of the high-quality papers 1 to 3 used for preparing each release paper, and the coating surface of the sealing layer immediately after coating is applied. Visual observation was made and the following criteria were evaluated.
〔Evaluation criteria〕
◎: No streaking 〇: Small streaks are partly △: Small streaks (streaks with the same width as the wire diameter of the wire bar) are all over the surface ×: Large streaks (the width is clearly larger than the wire diameter of the wire bar) There are wide stripes)

<Light transmission>
Each manufactured release paper was measured for light transmittance at a wavelength of 940 nm to 960 nm with a spectrophotometer (manufactured by Hitachi High-Technologies Corporation, U-4100), and the light transmittance was measured according to the following criteria based on the light transmittance at a wavelength of 940 nm. evaluated.
〔Evaluation criteria〕
○: Light transmittance at wavelength 940 nm is 36% or more Δ: Light transmittance at wavelength 940 nm is 35% or more and less than 36% ×: Light transmittance at wavelength 940 nm is less than 35%

<Peeling characteristics>
Each of the produced pressure-sensitive adhesive labels for thermal recording was cut into a size of 5 cm in length and 20 cm in width, and peeled off under the conditions of a 180 ° tensile angle when the release paper was peeled off from the pressure-sensitive adhesive label and a peeling speed of 0.3 m / min. The peel strength at the time of the measurement was measured with a tensile tester (manufactured by Shimadzu Corp., Autograph) and evaluated according to the following criteria.
〔Evaluation criteria〕
○: Peeling force is 50 mN / 50 mm or more and 200 mN / 50 mm or less Δ: Peeling force is 201 mN / 50 mm or more and 300 mN / 50 mm or less ×: Peeling force is 301 mN / 50 mm or more

From the results of Table 1, the results of comparing Reference Examples 1 to 8, Comparative Reference Example 1 and Comparative Examples 2 to 3 indicate that the sealing layer contains a water-soluble resin and an acetylene glycol compound, thereby providing coating properties and light. It was found that the permeability was good.
From the results of comparing Reference Examples 1 to 10, 11, 14 , 15, 19, Examples 12 to 13, 16 to 18 and Comparative Reference Example 1 and Comparative Examples 2 to 5, an intermediate between the sealing layer and the release layer It was found that the peelability was further improved by providing the layer.

(Example 23)
The heat-sensitive recording pressure-sensitive adhesive label obtained in Example 17 was punched into a heat-sensitive recording pressure-sensitive adhesive label sheet as shown in FIG. FIG. 4 shows a label printer (made by Ishida Co., Ltd., IL2000SA) that performs label detection using a light transmission type sensor (using a wavelength of 940 nm to 960 nm) by prism reflection, using the adhesive label sheet for thermal recording. Labels (kanji, hiragana, katakana, numbers, and barcodes) were issued continuously. When 500 labels were continuously issued, no sensing failure occurred. In addition, the same result was obtained also in the adhesive labels for thermal recording of Reference Examples 1 to 10, 11, 14 , 15, 19 and Examples 12 to 13, 16 to 18 , and 20 to 22.

(Comparative Example 7)
The heat-sensitive recording pressure-sensitive adhesive label obtained in Comparative Example 6 was punched into a heat-sensitive recording pressure-sensitive adhesive label sheet as shown in FIG. FIG. 4 shows a label printer (made by Ishida Co., Ltd., IL2000SA) that performs label detection using a light transmission type sensor (using a wavelength of 940 nm to 960 nm) by prism reflection, using the adhesive label sheet for thermal recording. Labels (kanji, hiragana, katakana, numbers, and barcodes) were issued continuously. When 500 labels were continuously issued, two sensing failures occurred.

The aspect of the present invention is as follows.
<1> A base paper, and a sealing layer and a release layer on the base paper in this order,
The sealing layer contains a water-soluble resin and an acetylene glycol compound,
An adhesive label release paper characterized by having a light transmittance of 35% or more at a wavelength of 940 nm.
<2> The adhesive label release paper according to <1>, wherein the content of the acetylene glycol compound is 0.05% by mass to 15% by mass.
<3> The pressure-sensitive adhesive label release paper according to any one of <1> to <2>, wherein an intermediate layer containing a water-soluble resin is provided between the sealing layer and the release layer.
<4> The release paper for adhesive labels according to <3>, wherein the water-soluble resin in the sealing layer and the intermediate layer is polyvinyl alcohol.
<5> The release paper for pressure-sensitive adhesive labels according to <4>, wherein the degree of polymerization of polyvinyl alcohol in the sealing layer is 300 to 2,000.
<6> The release paper for pressure-sensitive adhesive labels according to <4>, wherein the polymerization degree of polyvinyl alcohol in the intermediate layer is 1,000 to 2,400.
<7> The release paper for pressure-sensitive adhesive labels according to any one of <1> to <6>, wherein the release layer contains a solventless silicone resin.
<8> The pressure-sensitive adhesive label according to any one of <1> to <7>, wherein the base paper includes base paper, the air resistance of the base paper is 20 seconds or more, and the ash content is 8% by mass or less. Release paper for use.

1 Label 2 Gap (release paper)
3 Light Emitting Part 4 Light Receiving Part 10 Label Sheet

JP 2001-271295 A JP 2005-194673 A JP 2008-297653 A JP-A-9-176999 JP 2008-274465 A

Claims (6)

A base paper, and a sealing layer and a release layer on the base paper in this order;
The sealing layer contains polyvinyl alcohol and an acetylene glycol compound,
Between the sealing layer and the release layer, having an intermediate layer containing polyvinyl alcohol,
The degree of polymerization of the polyvinyl alcohol in the sealing layer is 300 to 2,000,
Polymerization degree of the polyvinyl alcohol in the intermediate layer is 1,000～2,400,
A pressure-sensitive adhesive label release paper having a light transmittance of 35% or more at a wavelength of 940 nm.   The release paper for pressure-sensitive adhesive labels according to claim 1, wherein the content of the acetylene glycol compound is 0.05% by mass to 15% by mass. The acetylene glycol compound is at least one selected from an acetylene glycol represented by the following general formula A and an ethylene oxide adduct of acetylene glycol represented by the following general formula B. The release paper for adhesive labels as described.
<General Formula A>
However, in the general formula A, R ¹ and R ² both represent an alkyl group.
<General formula B>
However, in the general formula B, R ¹ and R ² both represent an alkyl group. m and n are each a positive number of 0.5 to 25, and m + n is 1 to 40. In Formula A and B, R ¹ and R ² are adhesive labels for release paper according to claim 3 is an alkyl group having 1 to 10 carbon atoms. The release paper for pressure-sensitive adhesive labels according to any one of claims 1 to 4, wherein the release layer contains a solventless silicone resin. The release paper for pressure-sensitive adhesive labels according to any one of claims 1 to 5, wherein the base paper contains base paper, the air resistance of the base paper is 20 seconds or more, and the ash content is 8 mass% or less.