JP5312232B2 - Peelable film and adhesive tape or adhesive label using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a releasable film which combines good releasability and good printing properties, to provide an adhesive tape using the releasable film, and to provide an adhesive label using the releasable film with good deaeration when attached to an adherend. <P>SOLUTION: The releasable film has a laminate structure which includes an easy to print layer (A), a thermoplastic resin film layer (B), and an exfoliation layer (C) in this order, wherein the surface of the exfoliation layer (C) has a flat surface (c1) and a boring structure (c2), the boring structure (c2) is regularly arranged in at least one direction at an interval of 50-400 &mu;m on a surface of the exfoliation layer (C), an area ratio of the flat surface (c1) occupying the surface of the exfoliation layer (C) is in a range of 5-40%, a depth from the flat surface (c1) to a boring structure (c2) bottommost portion is in a range of 5-20 &mu;m, a cross-sectional configuration of the boring structure (c2) seen from a parallel direction with the flat surface (c1) is at least one of a lozenge shape and an ellipse, and a diagonal ratio (major axis/minor axis) of the cross-sectional configuration is in a range of 3-10. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  Conventionally, a biaxially oriented polypropylene film provided with a release agent layer on one side has been widely used industrially as a peelable film. Furthermore, the surface of the peelable film that is opposite to the peeled surface is coated with a pressure-sensitive adhesive, and in addition, after the pressure-sensitive adhesive is coated on the peelable film, the surface is printed. What was pasted with the film etc. which are upper papers is used as an adhesive label.

Adhesive tapes using a peelable film are not easily torn even when pulled and have high strength, and are widely used for, for example, cardboard packaging. However, if a silicone-based release agent that is widely used in various fields as a release agent is used, the writing property with a writing instrument such as magic and the adhesion of ink during printing to the release surface are poor. A release agent made of a long-chain alkyl-modified ethylene-vinyl alcohol copolymer resin as described in Document 1 has been used for many years as a release agent for pressure-sensitive adhesive tapes.
However, such a non-silicone release agent has the disadvantage that the force required for peeling between the adhesive surface and the release surface is greater than that of the silicone release agent, and in addition, the adhesive tape is stored at a high temperature for a long time. In such a case, there is a drawback that the force required for peeling is further increased. As a release agent with improved writability and printability, a technique using a peelable polymer such as a styrene-modified acrylic resin as described in Patent Document 2 is also mentioned, but for improving writability and printability. Accordingly, this also has the disadvantage that the force required for peeling increases.

  Another application of the peelable film is a pressure-sensitive adhesive label separator. In this case, since the release surface coated with the release agent does not come out on the outer surface, writing property and printability on the same surface are not particularly required, and a silicone release agent is usually used. The invention described in Patent Document 3 relates to a pressure-sensitive adhesive label, and in particular, a printing paper is bonded to a release-processed paper having a surface uneven shape, and the uneven shape is transferred to the pressure-sensitive adhesive surface, and applied to an adherend. The present invention relates to a pressure-sensitive adhesive label with good air escape. In the present invention, a release-processed paper having surface irregularities is obtained by embossing the release-processed paper. However, in this method, when the uneven shape is imparted to the release-processed paper by embossing, the processed paper is partially broken due to high-temperature and high-pressure conditions, and the yield tends to decrease. Therefore, if the release-processed paper is thinned for the purpose of cost reduction, troubles that break during processing under high-temperature and high-pressure conditions occur. Therefore, the release-processed paper needs to be thick, and the release-processed paper tends to be expensive. There is room for improvement.

  As a method for producing a release-processed paper having an uneven surface shape, a method of obtaining a release-processed paper by applying a silicone agent to a processed paper having an uneven surface shape is considered. Since the agent tends to accumulate, the silicone agent coating amount is likely to be distributed (uneven), and as a result, the force required for peeling becomes unstable. When the force required for peeling increases in the adhesive label, especially when using a flexible plastic polyvinyl chloride film such as the upper paper for printing in the following patent document, If the adhesive label is to be peeled off after being stuck to the adherend, the film as the upper paper for printing is stretched and the appearance of the paper is greatly impaired.

Japanese Patent Laid-Open No. 55-142096 Utility Model Registration No. 3032012 Japanese Patent No. 3950115

Therefore, in conventional peelable films used for pressure-sensitive adhesive tapes and pressure-sensitive adhesive labels, the force required for peeling of the peeled surface is stable without increasing (hereinafter referred to as good peelability), and further writing on the peeled surface. Actually, no material having good printability and printability (hereinafter referred to as good printability) and capable of being thinned has not been found.
The object of the present invention is to provide a peelable film that achieves both good peelability and printability in order to solve this problem in view of the above-mentioned problems of peelable films used for conventional adhesive tapes and adhesive labels. In addition, another object of the present invention is to provide an adhesive tape using the peelable film, or to provide an adhesive label with good air escape when an adherend is pasted using the peelable film.

In order to solve the above problems, the present inventors have made extensive studies from the viewpoint of a peelable film, and as a result, can use the peelable film having the following constitution to solve the above problems in the pressure-sensitive adhesive tape and pressure-sensitive adhesive label. As a result, the present invention has been completed.
That is, the present invention
1. A peelable film having a laminate structure including an easily printable layer (A), a thermoplastic resin film layer (B), and a release layer (C) in this order, and the surface of the release layer (C) is a flat surface (c1) And a perforated structure (c2), and using a non-contact three-dimensional surface shape roughness measuring device, the surface direction three-dimensional surface shape is measured with a measurement area: 2 mm × 2 mm, objective lens: 20 times, wavelength of 14 μm or less When the measurement is performed under the condition of cutting, the perforated structure (c2) on the surface of the release layer (C) is regularly arranged in at least one direction at intervals of 50 to 400 μm, and is formed on the surface of the release layer (C). The area ratio of the occupied flat surface (c1) is in the range of 5 to 40%, the depth from the flat surface (c1) to the bottom of the perforated structure (c2) is in the range of 5 to 20 μm, and the flat surface (c1) The cross-sectional shape of the perforated structure (c2) viewed in the direction parallel to the rhombus and ellipse Peelable film is at least one, and diagonal ratio of the cross-sectional shape (major axis / minor axis) is equal to or in the range of 3 to 10,

2. The release layer (C) is a resin layer (c3) in which a flat surface (c1) and a perforated structure (c2) are formed with a polyolefin resin as a main component, and a silicone release agent provided on the resin layer (c3) by coating. The peelable film according to 1 above, which is formed from the layer (c4),
3. The resin layer (c3) is made of a resin composition containing a thermoplastic resin and an additive, and the bleedout amount of the additive from the resin layer (c3) to the surface of the same layer is 10 to 200 mg / m ^2. The peelable film according to 2 above, characterized by:
4). Before the silicone release agent layer (c4) is provided on the resin layer (c3), the surface of the resin layer (c3) is subjected to corona discharge treatment with a discharge density of 10 to 50 W · min / m ^2. The peelable film according to 2 or 3,

5. In the release layer (C), the silicon abundance ratio (s1 / s2) determined from the Si amount (s1) observed on the flat surface (c1) and the Si amount (s2) observed in the perforated structure (c2) portion. The peelable film as described in any one of 2 to 4 above, wherein is in the range of 0.8 to 1.2,
6). The gravure ink is solid-printed on the surface of the release layer (C) in an amount of ² g / m ² , and the same surface after drying the ink is subjected to Gakushin type friction tester and No. 3 in accordance with JIS-L-0849: 2004. The peelable film as described in any one of 1 to 5 above, wherein the residual ink ratio after the friction test is performed 50 times with a load of 500 g is 60 to 100%,
7). The peelable film according to any one of the above 1 to 6, wherein the thermoplastic resin film layer (B) comprises a polyolefin resin and at least one of an inorganic filler and an organic filler as a main constituent material,

8). The easily printable layer (A) is a layer provided on the thermoplastic resin film layer (B) by coating, contains a polymer type antistatic agent, and has a surface resistivity (JIS-K-6911: 1995) is 10 ⁸ to 10 ¹³ Ω / m ² , the surface water contact angle (JIS-R-3257: 1999) is 60 to 100 °, and the arithmetic average surface roughness Ra (JIS-B-0601). : 1994) is 0.2 to 0.9 μm, the peelable film according to any one of the above 1 to 7,
9. A pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer (D) on the easily printable layer (A) of the peelable film according to any one of 1 to 8 above,
10. After the peelable film is rolled up continuously in the longitudinal direction, the pressure-sensitive adhesive layer is coated on the easily printable layer (A) while being unwound, and dried to obtain a pressure-sensitive adhesive layer (D). The pressure-sensitive adhesive tape as described in 9 above, wherein the pressure-sensitive adhesive tape is rolled up again.

11. After adjusting the pressure-sensitive adhesive tape at 23 ° C. for 2 weeks, the pressure-sensitive adhesive layer (D) was contact bonded to the surface of a flat SUS304 plate, and further pressure-bonded for 1 hour under a load of 10 g / cm ² under the condition of 23 ° C. Thereafter, 180 ° peel strength (JIS-K-6854-2: 1999) measured at a peel rate of 300 mm / min using a tensile tester was taken as room temperature adhesive force (N / 50 mm),
Separately, the pressure-sensitive adhesive tape was adjusted at 70 ° C. for 20 hours, then cooled at 23 ° C. for 30 minutes, and the pressure-sensitive adhesive layer (D) was contact bonded to the flat SUS304 plate surface. After applying pressure for 1 hour under a load of / cm ² , 180 ° peel strength (JIS-K-6854-2: 1999) measured at a peel rate of 300 mm / min using a tensile tester was applied to the high-temperature adhesive force (N / 50 mm). )
10. The pressure-sensitive adhesive tape according to 10 above, wherein the adhesive force retention determined by the following formula (1) is in the range of 80 to 99%.
Adhesive strength retention rate (%) = high temperature adhesive strength / room temperature adhesive strength × 100 (1)
12 A pressure-sensitive adhesive label in which a pressure-sensitive adhesive layer (D) and a label paper (E) are provided in this order on the release layer (C) of the peelable film according to any one of 1 to 8 above, wherein JIS-K- 7133: The ratio of the heat shrinkage rate of the thermoplastic resin film layer (B) measured in accordance with 1999 and the heat shrinkage rate of the label upper paper (E) is in the range of 0.7 to 1.3. Features adhesive labels,

13. 13. The pressure-sensitive adhesive label as described in 12 above, wherein the label upper paper (E) is a resin film containing a polyolefin resin as a main constituent material,
14 13. The label upper paper (E) is a synthetic paper comprising a polyolefin-based resin and at least one of an inorganic filler and an organic filler as a main constituent material and formed by stretching, Adhesive label,
15. 13. The pressure-sensitive adhesive label as described in 12 above, wherein the label upper paper (E) is a paper containing natural pulp as a main constituent material.

  The present invention eliminates the problems of peelable films used in conventional pressure-sensitive adhesive tapes and pressure-sensitive adhesive labels, and provides a peelable film that achieves both good peelability and printability. Furthermore, the peelable film It is possible to provide a pressure-sensitive adhesive tape using the above-mentioned adhesive label, and to provide a pressure-sensitive adhesive label with good air escape when the adherend is stuck using the peelable film.

Sectional drawing which shows the example of an aspect of the peelable film of this invention. The schematic diagram which shows the structure in the cross-sectional direction of the peeling layer (C) of the peelable film of this invention. The schematic diagram which shows the structure in the bird's-eye view direction of the peeling layer (C) of the peelable film of this invention.

Below, the peelable film, adhesive tape, and adhesive label of this invention are demonstrated in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
"Peelable film"
The configuration of the peelable film of the present invention will be described.
The peelable film of the present invention is a film having a laminated structure including an easily printable layer (A), a thermoplastic resin film layer (B), and a peelable layer (C) in this order. Hereinafter, each component will be described.

"Thermoplastic resin film layer (B)"
The peelable film of the present invention includes a thermoplastic resin film layer (B). The thermoplastic resin film layer (B) serves as a core material for the peelable film to facilitate the production of the peelable film, and imparts characteristics such as water resistance, strength, and rigidity to the peelable film. The thermoplastic resin film layer (B) contains a thermoplastic resin as its main constituent material. The thermoplastic resin film layer (B) preferably contains at least one of an inorganic filler and an organic filler in addition to the thermoplastic resin as the main constituent material. The structure of the thermoplastic resin film layer (B) may be a single layer or a laminated film composed of two or more layers.

[Thermoplastic resin]
The thermoplastic resin is used as a main constituent material (matrix resin) of the thermoplastic resin film layer (B).
Examples of the thermoplastic resin that can be used for the thermoplastic resin film layer (B) include ethylene resins such as high density polyethylene, medium density polyethylene, and low density polyethylene, and polyolefin resins such as propylene resin and polymethyl-1-pentene. Polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12, polyethylene terephthalate mainly composed of ethylene glycol and terephthalic acid, and copolymers of ternary or higher, Examples thereof include thermoplastic polyester resins such as aliphatic polyesters such as polyethylene naphthalate, polylactic acid, and polybutylene succinate, 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, from the viewpoint of chemical resistance and production cost, it is preferable to use a polyolefin resin as the thermoplastic resin, and it is more preferable to use a propylene resin.
As the propylene-based resin, it is preferable to use an isotactic polymer or a syndiotactic polymer obtained by homopolymerizing propylene. Also, propylene-based compounds having various stereoregularities mainly composed of propylene and copolymerized with α-olefins such as ethylene, 1-butene, 1-hexene, 1-heptene and 4-methyl-1-pentene. Copolymers can also be used. The copolymer may be a binary system or a ternary or higher multi-element system, and may be a random copolymer or a block copolymer.

[Inorganic filler and / or organic filler]
The inorganic filler and / or organic filler is added as a constituent material of the thermoplastic resin film layer (B) for the purpose of forming pores when imparting whiteness and stretching.
Examples of inorganic fillers that can be used for the thermoplastic resin film layer (B) include heavy calcium carbonate, light calcium carbonate, calcined clay, talc, titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, and silicon oxide. Examples thereof include inorganic fillers, composite inorganic fillers having inorganic fillers as the core and aluminum oxide or hydroxide around them, and hollow glass beads. Among them, heavy calcium carbonate, calcined clay, and diatomaceous earth are preferable because they are inexpensive and can form many pores during stretching.

  Further, usable organic fillers are selected from resins having a melting point or glass transition point higher than that of the thermoplastic resin used as a matrix and incompatible with the thermoplastic resin for the purpose of pore formation. And preferably used. Specific examples of the organic filler include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polystyrene, polycarbonate, acrylic acid ester or methacrylic acid ester homopolymer or copolymer, melamine resin, polyimide, polyethylene sulfide, Examples thereof include polyphenylene sulfide, polyethyl ether ketone, homopolymers of cyclic olefins, and copolymers (COC) of cyclic olefins and α-olefins such as ethylene. When a crystalline polyolefin-based resin is used as the thermoplastic resin, as an organic filler, in particular, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polystyrene, polycarbonate, cyclic olefin homopolymer, cyclic olefin It is preferable to use one selected from a copolymer (COC) with ethylene or the like.

[Combination ratio]
The raw material composition of the thermoplastic resin film layer (B) includes 20 to 90% by weight of the above thermoplastic resin and 10 to 80% by weight of at least one of an inorganic filler and an organic filler, preferably the thermoplastic resin 40. -80 wt% and at least one of inorganic filler and organic filler 20-60 wt%, more preferably thermoplastic resin 50-80 wt%, and at least one inorganic filler and organic filler 20-50 wt% % Is included.

[Production method]
The thermoplastic resin film layer (B) can be produced by various methods known to those skilled in the art as an unstretched film or a stretched film, and combinations thereof. Any thermoplastic resin film produced by any method is included within the scope of the present invention as long as it satisfies the conditions described in the present invention.
When the thermoplastic resin film layer (B) used in the present invention is a stretched film, the thermoplastic resin and the inorganic filler and / or the organic filler are mixed at a predetermined ratio, melt-kneaded, and then extruded. The film is formed and then stretched in a uniaxial direction or biaxial direction under a temperature lower than the melting point of the thermoplastic resin, preferably 5 to 60 ° C. after film formation.
In the present invention, when two or more kinds of thermoplastic resins are mixed and used, the stretching is performed at a temperature lower by 5 ° C. or more than the melting point of the thermoplastic resin in which the blending amount (% by weight) of the thermoplastic resin to be used is maximum. preferable.

  In the present invention, when a multilayer film is used as the thermoplastic resin film layer (B), the layer (B) may be obtained by laminating each layer individually and then laminating them. It may be obtained by stretching. The thermoplastic resin film layer (B) is formed, for example, by laminating the resin composition of the surface layer (A) on the front and back surfaces of the base layer (A) to obtain a multilayer structure of A / A / A, and then uniaxial or biaxial By stretching in the direction, it can be obtained as a multi-layer film oriented in all layers uniaxial direction or all layers biaxial direction. In addition, after extending the base layer (a) in the uniaxial direction, the front and back surfaces (a) are laminated on the front and back surfaces to form a multi-layer structure of A / A / A, and the uniaxial stretching is performed again on a different stretching axis from the previous stage. By doing so, it can also be obtained as a multilayer film oriented in a uniaxial / 2 biaxial / 1 uniaxial direction.

Although it is possible to laminate after each layer is stretched separately, it is simpler to stretch the layers after laminating each layer as described above, because the number of steps is small and the manufacturing cost is low. It is preferable to obtain the thermoplastic resin film layer (B) of the present invention by these methods.
Various methods known to those skilled in the art can be used for stretching.
As specific methods of stretching, inter-roll stretching using the peripheral speed difference of the roll group, clip stretching using a tenter oven, simultaneous biaxial stretching using a tenter oven and a linear motor, tenter oven and pantograph were used. Examples thereof include simultaneous biaxial stretching and inflation (simultaneous biaxial stretching) formation using a tubular method. According to the roll-to-roll stretching, it is easy and preferable to obtain a thermoplastic resin film layer (B) having arbitrary rigidity, cushioning properties, opacity, and lightness by arbitrarily adjusting the stretching ratio.

The draw ratio is not particularly limited, and is determined in consideration of the physical properties desired for the thermoplastic resin film layer (B) of the present invention and the properties of the thermoplastic resin used. The stretching between rolls is usually preferably 4 to 11 times, more preferably 4 to 10 times, and further preferably 5 to 7 times. In the case of clip stretching using a tenter oven, it is preferably 4 to 11 times, and more preferably 6 to 9 times. The combined biaxially stretched area ratio is usually 4 to 80 times, preferably 4 to 60 times, and more preferably 5 to 50 times. By making the area magnification 4 times or more, there is a tendency that it becomes easier to produce the thermoplastic resin film layer (B) having a lower density, more voids, and prevention of uneven stretching, and a more uniform thickness. is there. Further, by making it 80 times or less, there is a tendency that it is possible to more effectively prevent stretch breaks and coarse perforations.

  It is preferable to heat-treat the stretched thermoplastic resin film layer (B). The temperature of the heat treatment is preferably selected within the range of a temperature 30 ° C. higher than the stretching temperature from the stretching temperature. By performing the heat treatment, the thermal shrinkage rate due to the stretching stress in the stretching direction is reduced, and sheet undulation and the like resulting from tightening during product storage and shrinkage due to heat are reduced. The heat treatment is generally performed by roll heating or a heat oven, but may be combined. In these treatments, it is preferable to heat-treat the stretched film in a state where the stretched film is held under tension because a higher treatment effect can be obtained.

"Easily printable layer (A)"
In the peelable film of the present invention, an easily printable layer (A) is provided on one surface of the thermoplastic resin film layer (B) in order to impart surface printability and antistatic property thereto. The easily printable layer (A) is preferably provided on the thermoplastic resin film layer (B) by coating.
The easy-printing layer (A) contains a polymer type antistatic agent, particularly for the purpose of preventing the generation of static electricity during printing, and is measured according to JIS-K-6911: 1995 on the surface. The surface specific resistance value is preferably 10 ⁸ to 10 ¹³ Ω / m ² , and more preferably 10 ⁹ to 10 ¹² Ω / m ² . When the specific resistance value on the same surface exceeds 10 ¹³ Ω / m ² , the antistatic effect at the time of printing becomes insufficient, and the runnability of the peelable film on the printing press paper supply side deteriorates during printing. The paper alignment on the paper discharge side may deteriorate. On the other hand, if it exceeds 10 ⁸ Ω / m ² , the number of polar groups increases on the same surface, and the adhesiveness of the printing ink may decrease, which is not preferable.

Furthermore, the surface of the easily printable layer (A) preferably has a water contact angle of 60 to 100 ° measured in accordance with JIS-R-3257: 1999 in order to maintain the offset printability. More preferably, the angle is 95 °. When the water contact angle exceeds 100 °, it is not preferable because the ink wettability is lowered or the ink adhesion is lowered. Conversely, when the water contact angle is less than 60 °, a water loss phenomenon during offset printing occurs, and the printed appearance such as halftone dots deteriorates, which is not preferable.
Furthermore, it is preferable that arithmetic mean surface roughness Ra measured based on JIS-B-0601: 1994 of the surface of an easily printable layer (A) is 0.2-0.9 micrometer, 0.3-0 More preferably, it is 8 μm. When the surface roughness Ra exceeds 0.9 μm, the surface unevenness becomes too large, so that the halftone dot reproducibility is lowered and the appearance of the printed matter is deteriorated. A surface roughness Ra of less than 0.2 μm is not preferable because the ink adhesion improvement effect (anchor effect) due to surface irregularities is reduced.

[Polymer binder]
In the peelable film of the present invention, the easily printable layer (A) contains a polymer binder in order to improve the fixing property of the printing ink and the adhesion to the thermoplastic resin film layer (B).
Specific examples of the polymer binder include polyurethane resin, polyester resin, vinyl acetate resin, acrylic ester resin, styrene-acrylic ester copolymer, vinyl acetate-acrylic ester copolymer, styrene-butadiene. Copolymers, aqueous emulsions such as methyl methacrylate-butadiene copolymer, polyvinyl alcohol, ethylene / vinyl alcohol copolymers containing silanol groups, polyethyleneimine, polyamine polyamide, polyvinyl acetal, polyvinyl pyrrolidone, methyl ethyl cellulose, polyacrylic acid Water-soluble polymers such as soda, various starches and various gelatins can be mentioned.

（式中、Ｒ^１とＲ^２はそれぞれ独立して水素原子または炭素数１〜１０の範囲の直鎖または分岐状のアルキル基、脂環式構造を有するアルキル基、アリル基であり、Ｒ^３は水素原子または炭素数１〜２０の範囲のアルキル基、アリル基、脂環式構造を有するアルキル基、アリル基乃至はこれらの水酸化物であり、ｍは２〜６の範囲の整数であり、ｎは２０〜３０００の範囲の整数であり、これらを単独または数種類複合させても良い。） Among the above polymer binders, a polyethyleneimine polymer represented by the following general formula (I) or an ethyleneimine of a polyamine polyamide is represented by the following general formula (I) from the viewpoint of improving ink fixing properties and adhesion to the thermoplastic resin film layer (B). Adducts are preferred.

Wherein R ¹ and R ² are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, an alkyl group having an alicyclic structure, or an allyl group, and R ³ Is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, an allyl group, an alkyl group having an alicyclic structure, an allyl group or a hydroxide thereof, and m is an integer in the range of 2 to 6. , N is an integer in the range of 20 to 3000, and these may be used alone or in combination.

[Polymer type antistatic agent]
In the peelable film of the present invention, the easily printable layer (A) contains a polymer antistatic agent for the purpose of preventing the generation of static electricity during printing.
Examples of the polymer type antistatic agent that can be used include cationic type, anionic type, amphoteric type, and nonionic type. Examples of the cationic type include those having an ammonium salt structure or a phosphonium salt structure. Anionic types include alkali metal salts such as sulfonic acid, phosphoric acid and carboxylic acid, for example, alkali metal salts such as acrylic acid, methacrylic acid and (anhydrous) maleic acid (for example, lithium salt, sodium salt, potassium salt, etc. ) Having a structure in the molecular structure.
The amphoteric type contains both the above cation type and anion type structures in the same molecule, and examples include betaine type. Examples of the nonionic type include an ethylene oxide polymer having an alkylene oxide structure and a polymer having an ethylene oxide polymerization component in a molecular chain. In addition, a polymer type antistatic agent having boron in the molecular structure can be given as an example. Among these, a nitrogen-containing polymer type antistatic agent is preferred, and an acrylic polymer containing tertiary nitrogen or cationic quaternary nitrogen is more preferred.

[Filler component]
As long as the adhesiveness with the thermoplastic resin film layer (B) does not decrease, it is possible to incorporate a filler component in the easily printable layer (A) as an ink fixing component or a whiteness improving component. Specific examples of the filler component include synthetic silica, colloidal silica, alumina hydrosol, aluminum hydroxide, talc, calcium carbonate, clay, barium sulfate, titanium dioxide, plastic pigment, etc. Among them, calcium carbonate, silica, It is preferable to use an inorganic filler such as clay or barium sulfate.

[Other ingredients]
The easy-printing layer (A) may contain an epoxy-based, isocyanate-based, formalin-based, or oxazoline-based crosslinking agent. When these resins are added, the water-resistant adhesion between the easily printable layer (A) and the printing ink can be further improved. As the cross-linking agent, bisphenol A-epichlorohydrin resin, polyamine polyamide epichlorohydrin resin, aliphatic epoxy resin, epoxy novolac resin, alicyclic epoxy resin, brominated epoxy resin are preferable, and polyamine polyamide epichlorohydrin adduct or monofunctional Particularly preferred are polyfunctional glycidyl ethers and glycidyl esters. In addition, you may add an antifoamer, another adjuvant, etc. as needed to the easily printable layer (A) which comprises this invention in the range which does not impair printability and adhesiveness.

[Combination ratio]
The blending ratio of the easily printable layer (A) is 20 to 90% by weight of the polymer binder, 1 to 60% by weight of the polymer type antistatic agent, 0 to 60% by weight of the filler component, and other components 0 such as a crosslinking agent. It is preferably ˜40% by weight.

[Activation processing]
Before providing the easy-printable layer (A) on the thermoplastic resin film layer (B) by coating, various activation treatments are performed on the surface of the thermoplastic resin film layer (B) in order to improve the adhesion between them. May be. The activation treatment is at least one treatment method selected from corona discharge treatment, flame treatment, plasma treatment, glow discharge treatment and ozone treatment, preferably corona discharge treatment. An appropriate processing amount in the corona discharge treatment is 5 to 200 W · min / m ² , preferably 10 to 100 W · min / m ² . If it is less than 5 W · min / m ² , the effect of the corona discharge treatment is insufficient, and when the easy-printable layer (A) is provided by subsequent coating, repellency tends to occur, which is not preferable. If it exceeds 200 W · min / m ² , the effect of the treatment reaches its peak, and 200 W · min / m ² or less is sufficient. After providing the easily printable layer (A), the surface may be further subjected to the above activation treatment.

[Coating method]
As an easy printing layer (A), as a coating method for providing an aqueous solution (hereinafter referred to as a coating agent) containing the above polymer binder and antistatic agent on the thermoplastic resin film layer (B), A coating method such as a die, a bar, a roll, a gravure, a spray, a blade, an air knife, and a size press and a method combining these coating methods can be employed. Depending on the viscosity, coating amount, and coating speed of the coating agent, a specified amount of coating agent can be measured using a die, roll, gravure, spray, etc. and transferred to a roll or size press for coating. After transferring a specified amount of coating agent with a die or roll, scrape off the excess coating agent with a bar, blade, air knife, etc., and apply a specified amount of coating agent, die, spray, etc. It is possible to apply a prescribed amount of coating agent directly using As a more specific example, the coating agent is applied at a viscosity of 10 to 1000 cP (0.01 to 1 Ns / m ² ), a coating amount of 1 to 20 g / m ² and a coating speed of 300 m / min or less. As the coating method, an offset gravure method, a spray system, or rotor dampening can be used. The offset gravure method is a combination of gravure and roll. The coating agent is transferred from the gravure plate to the roll, and when the liquid is transferred between the rolls, the gravure plate is removed and the coating agent is smoothed. After being broken, it is transferred to the surface of each layer.

In addition, the spray system that combines the spray and the size press allows the coating agent to form a uniform coating agent film on the size press from the supply device through the spray coating device, and from the size press to the thermoplastic resin film layer (B). Since it is transferred, it is preferable as a method for applying a small amount of coating agent. Rotor dampening is a type of spray coating, in which the coating agent is atomized by a rotor that rotates at high speed by driving a belt and sprayed directly onto the surface of each layer. After coating the coating agent on the thermoplastic resin film layer (B), smoothing (surface smoothing treatment) is performed as necessary, and excess water and hydrophilic solvent are removed through a drying process. A printable layer (A) is obtained.
In the present invention, the polymer antistatic agent in the easy-printable layer (A) provided on the surface of the thermoplastic resin film layer (B) is 0.001 to 10 g as a solid content per unit area (m ² ), preferably Is 0.002 to 8 g, more preferably 0.002 to 5 g, and particularly preferably 0.005 to 0.1 g. When the polymer type antistatic agent distribution amount is less than 0.001 g, the antistatic effect does not sufficiently appear, and when it exceeds 10 g, the adhesion of the printing ink tends to be insufficient.

[Additional surface treatment]
When printability and antistatic properties are insufficient with the above-described easily printable layer (A), a coating layer containing a pigment can be further provided. This pigment coat layer can be formed by performing pigment coating on the easily printable layer (A) according to a general method for producing coated paper. Examples of pigment coating agents used for the pigment coating layer include pigments such as clay, silica, talc, calcium carbonate, magnesium carbonate, calcium silicate, aluminum hydroxide, and plastic pigment used in general coated paper 30 to 80% by weight. And latex composed of 20 to 70% by weight of an adhesive.
In addition, as an adhesive used in this case, latex such as SBR (styrene / butadiene copolymer rubber), MBR (methacrylate / butadiene copolymer rubber), acrylic emulsion, starch, PVA (polyvinyl alcohol), CMC (carboxymethylcellulose), methylcellulose, etc. can be mentioned. Furthermore, these pigment coating agents can be blended with a dispersing agent such as special sodium polycarboxylate such as acrylic acid / sodium acrylate copolymer and a crosslinking agent such as polyamide urea resin. These pigment coating agents are usually used as a water-soluble coating agent having a solid content of 15 to 70% by weight, preferably 35 to 65% by weight.

"Peeling layer (C)"
The peeling layer (C) in this invention is a layer provided in the surface on the opposite side to the surface which provides an easily printable layer (A) among the both sides | surfaces of the thermoplastic resin film layer (B) of the peelable film of this invention. It is a layer in contact with the pressure-sensitive adhesive when the pressure-sensitive adhesive layer is provided to form a pressure-sensitive adhesive tape or a pressure-sensitive adhesive label. The feature is that the outer surface has a flat surface (c1) and a perforated structure (c2), the perforated structures (c2) are regularly arranged on the surface, and the area ratio of the flat surface (c1) is within a certain range. In addition, the sectional shape of the perforated structure (c2) is defined. Due to these characteristics, distribution (unevenness) in the coating amount of the silicone agent is difficult to be achieved, and good peelability of the release surface is obtained, and good printability (writing property) is obtained by providing unevenness, and both are compatible. Became possible.
The release layer (C) of the present invention comprises a resin layer (c3) in which a flat surface (c1) and a perforated structure (c2) are formed in advance, and a silicone release agent layer (c3) provided on the resin layer (c3) by coating ( c4). According to this method, the perforated structure (c2) can be easily imparted to the peelable film, and the peelable film can be thinned.
As long as the release layer (C) to the resin layer (c3) provided on the thermoplastic resin film layer (B) are produced by any method, they satisfy the conditions described in the present invention. Included within the scope of the present invention.

[Flat surface (c1) and perforated structure (c2)]
A flat surface (c1) and a perforated structure (c2) are formed on the surface of the release layer (C) in the present invention. The perforated structure (c2) is regularly arranged on a plane, and the area ratio of the flat surface (c1) on the plane (similarly, the area ratio of the portion of the perforated structure (c2) on the plane) is in a certain range. .
The perforated structure (c2) is regularly arranged in at least one direction at intervals of 50 to 400 μm on the surface of the release layer (C), and the area ratio of the flat surface (c1) occupying the surface of the release layer (C) is 5 to 5. The range is 40%, preferably 10 to 30%.
If the distance between the perforated structures (c2) is less than 50 μm, or if the area ratio of the flat surface (c1) is less than 5%, the silicone release agent is concentrated on the perforated structure (c2). This is not preferable because the peelability tends to decrease. Conversely, when the interval between the perforated structures (c2) exceeds 400 μm, or when the area ratio of the flat surface (c1) exceeds 40%, the printability, in particular, the adhesion of the printing ink tends to be reduced, which is preferable. Absent. On the other hand, when the distance exceeds 400 μm, the uneven pattern becomes clear and tends to be poor in appearance or poor in writing.

The formation method of the flat surface (c1) and the perforated structure (c2) is a metal roll in which a surface irregularity pattern is attached to a cooling roll when the resin layer (c3) for forming the release layer (C) is formed by T-die extrusion or the like. It is preferable to employ an embossing roll processing method, which is a molding method using (embossing roll).
In forming the perforated structure (c2), the release layer (C) having the perforated structure (c2) may be formed by various methods known to those skilled in the art and combinations thereof, even if the embossing roll processing method described above is employed. Can be manufactured. For example, a drilling method such as a mechanical drilling method using a roller with diamond particles, a hot needle, a punching blade, a laser beam punching method, an electron irradiation punching method, a plasma punching method, a high-pressure discharge punching method, etc. can be applied. ) Can be appropriately selected according to the material, thickness, passage speed, and perforation diameter of the resin layer (c3).

[Shape of perforated structure (c2)]
In the present invention, the shape of the perforated structure (c2) in the release layer (C) is linear, broken line, wavy, circular, elliptical, triangular, or n-gonal (n is a natural number of 5 or more), arbitrary However, in order to achieve both peelability and printability, the cross-section of the perforated structure (c2) viewed in a direction parallel to the flat surface (c1) has a rhombus shape. It was found that at least one of a shape and an elliptical shape is an essential condition.
For example, when the concave structure is linear, it is not preferable because the writing property is greatly different in the parallel direction or the vertical direction to the linear shape. Furthermore, in the case of squares, hexagons and arbitrary shapes, the writing property is good regardless of the writing direction, but the release property tends to decrease because the silicone release agent is concentrated in the perforated structure. It is not preferable.

In the present invention, the depth from the flat surface (c1) to the lowest part of the perforated structure (c2) is in the range of 5 to 20 μm. When the depth is less than 5 μm, the adhesion of the printing ink is lowered. Conversely, when it exceeds 20 μm, the printability is good, but the uneven pattern becomes clear and the appearance is poor, or the silicone peels off. Since the agent is intensively applied (flowed in) to the perforated structure (c2) portion, the distribution of the release agent becomes unstable, which tends to cause poor writing performance.
Furthermore, in the present invention, the diagonal ratio (major axis / minor axis) of the cross-sectional shape of the perforated structure (c2) is in the range of 3-10. The diagonal ratio (major axis / minor axis) is preferably 5-10.

The cross-sectional shape of the perforated structure (c2) viewed in the direction parallel to the flat surface (c1) is at least one of a rhombus and an ellipse, and the diagonal ratio (major axis / minor axis) of the shape is in the range of 3 to 10, It becomes easy to achieve both releasability and printability. When the diagonal ratio of the perforated structure (c2) is less than 3, the silicone release agent tends to be concentrated on the perforated structure, resulting in an uneven distribution of the silicone release agent coating amount, resulting in unstable release properties. This is not preferable. On the other hand, when the diagonal ratio exceeds 10, there is no problem in the stability of peeling, but the pattern of the perforated structure (c2) becomes clear and the rhombus shape is conspicuous when the label is visually observed as an adhesive label. Since it becomes easy, it is not preferable.
In the present invention, the perforated structure (c2) in the release layer (C) has a minor axis of the cross-sectional diagonal line in the running direction of the film and a major axis of the diagonal line orthogonal to the film as shown in FIG. It is preferable to arrange along the direction. That is, when the shape deviates from the above conditions, the silicone release agent tends to be deteriorated due to the silicone release agent being concentrated in the longitudinal direction of the perforated structure when the resin release agent (c3) is applied. Therefore, it is not preferable.

[Composition and formation of resin layer (c3)]
It is preferable that the resin layer (c3) mainly contains the same kind of thermoplastic resin as the thermoplastic resin film layer (B) and does not substantially contain a filler (inorganic filler and organic filler). Here, “substantially free” means that it is not intentionally included as a raw material blend, and the observed amount is preferably in the range of 0 to 1% by weight. Therefore, as the thermoplastic resin constituting the resin layer (c3) that forms the release layer (C), it is preferable to use a resin mainly composed of a polyolefin resin, similarly to the thermoplastic resin film layer (B).
The resin layer (c3) can also be formed by a method similar to the aforementioned manufacturing method. In consideration of industrial production, the resin layer (c3) is preferably produced in the same process as the thermoplastic resin film layer (B). For example, a laminate in which both are laminated by a co-extrusion method may be formed in a sheet shape, or may be laminated after the both are individually formed in a sheet shape.

The peelable film of the present invention may be composed of a stretched stretched film. For example, the easy-printable layer (A) or the resin layer (c3) is laminated before the thermoplastic resin film layer (B) is stretched, and stretched uniaxially or biaxially, so that all layers are uniaxially or All layers can be obtained as a laminated structure oriented in the biaxial direction. Further, the easily printable layer (A) and the resin layer (c3) can be laminated after the thermoplastic resin film layer (B) is stretched, and can be obtained by stretching all together after the lamination.
When the thermoplastic resin film layer (B) is a multilayer film, the base layer (a) is formed into a sheet shape and stretched in the uniaxial direction, and then formed into a sheet shape on the front and back surfaces (A). Are further laminated, and a release layer (C) to a resin layer (c3) are laminated on one of the surface layers (A), and are uniaxially stretched to different stretching axes, thereby being uniaxial / biaxial / uniaxial direction. It can also be obtained as a laminated structure oriented in the direction.

Each layer can be stretched and laminated separately, but it is simpler and the production cost is cheaper to stretch the layers after laminating them as described above. It is preferable to obtain the peelable film of the present invention using these methods.
Moreover, even when the resin layer (c3) is made of a resin composition containing a thermoplastic resin and an additive, the bleed-out amount of the additive from the resin layer (c3) to the layer surface is 10 to 200 mg / m ² . It is preferable to adjust the range. It said amount is more preferably in the range of 20 to 100 mg / ^{m 2.} The bleed-out amount of the additive on the surface of the resin layer (c3) is determined by considering the curing rate of the silicone release agent by applying the silicone release agent after embossing and providing the silicone release agent layer (c4). In order to maintain, it is preferable to reduce as much as possible. When the bleed-out amount of the additive exceeds 200 mg / m ² , the silicone release agent curing rate is remarkably lowered, which is not preferable. However, if the bleed-out amount of the additive is less than 10 mg / m ² , the thermal stability of the resin layer (c3) is remarkably lowered. Therefore, it is preferable to make the addition amount as low as possible within the above range. Examples of the additive that inhibits the curing of the silicone release agent herein include a radical scavenger, an ultraviolet absorber, and an antioxidant.
As specific means for adjusting the bleed-out amount of the additive to the surface of the resin layer (c3) within the above specific range, for example, the addition amount itself is made as low as possible, or the high molecular weight that is difficult to migrate In the present invention, an additive that is easy to migrate is made as low as possible in the present invention, such as selecting an additive for the resin, and selecting a structure designed to improve compatibility with the thermoplastic resin. Adjusted to do.

In the present invention, before the silicone release agent layer (c4) is provided on the resin layer (c3), the surface of the resin layer (c3) is subjected to a corona discharge treatment with a discharge density of 10 to 50 W · min / m ^2. Is preferable, and it is more preferable to perform the corona discharge treatment with an intensity of ^{20 to} 40 W · min / m ² .
By performing corona discharge treatment on the surface of the layer, in addition to improving the adhesion of the silicone release agent, it is possible to remove additives that have bleeded out to the surface of the layer, which is also an inhibitor when curing silicone It becomes. If the amount of corona discharge treatment is less than 10 W · min / m ² , the effect of the above-mentioned corona discharge treatment is insufficient. Conversely, if it exceeds 50 W · min / m ² , the effect of the treatment reaches a peak, and resin It tends to promote bleeding out of the additive in the layer (c3), and coating unevenness due to charging of the film surface is not preferable.

[Composition and formation of silicone release agent layer (c4)]
The release layer (C) of the present invention comprises a resin layer (c3) in which a flat surface (c1) and a perforated structure (c2) are previously formed, and a silicone release agent layer (by coating on the resin layer (c3)) ( c4)
It is preferable to form from.
As the silicone release agent constituting the silicone release agent layer (c4), those described in the Silicone Handbook (published by Nihon Kogyo Shimbun, pages 518 to 530) can be used. Widely used products that are sold as release silicone agents for films, such as curable silicones and silicone-modified thermosetting resins, can be used. Furthermore, a reaction control agent, a release adjusting agent, a slip improver and the like may be added to these raw materials as appropriate.
The coating amount of the above resin layer of a silicone release agent (c3) above, 0.03~5g / ^{m 2} as a solid content, preferably 0.05 to 1 g / ^{m 2.} If it is less than 0.03 g / m ² , most of it is intensively applied (flowed in) to the perforated structure (c2), and the distribution of the release agent becomes unstable, and the peelability from the adhesive tape or adhesive label is low. It tends to be insufficient. If it exceeds 5 g / m ² , the silicone release agent layer (c4) becomes too thick, and the adhesion between the resin layer (c3) and the release agent layer (c4) is unfavorable.

For the coating of the silicone release agent on the resin layer (c3), a die coater, bar coater, lip coater, roll coater, gravure coater, spray coater, blade coater, air knife coater, size press coater, etc. are used. Construction equipment can be used. However, in the present invention, in order to achieve stable peelability, a coating method in which a silicone release agent is applied equally to the flat surface (c1) and the perforated structure (c2), and a drying method are selected. Need to adopt.
The amount distribution of the silicone release agent in the release layer (C) is determined from the Si amount (s1) observed on the flat surface (c1) and the Si amount (s2) observed in the perforated structure (c2) portion. The silicon abundance ratio (s1 / s2) is preferably 0.8 to 1.2, more preferably 0.9 to 1.1. If it is out of the above range, distribution (unevenness) is likely to occur in the coating amount of the silicone agent, and as a result, the force required for peeling becomes unstable. In particular, when the silicon abundance ratio is less than 0.8, the silicone coating amount in the perforated structure (c2) portion becomes excessive, and the force required for peeling on a flat surface tends to increase. In addition, the perforated structure (c2) portion is not preferable because the adhesion between the resin layer (c3) and the release agent layer (c4) is lowered. Conversely, when the silicon abundance ratio exceeds 1.2, the silicone coating amount of the perforated structure (c2) portion is insufficient, and the force required for peeling at the portion tends to increase. In addition, it is not preferable because silicone easily migrates to the easily printable layer (A) which is the opposite surface, and the ink adhesion of the same layer is greatly impaired.

The peelable film of the present invention has good printability on the surface of the peelable layer (C) by achieving the above perforated structure (c2) and silicon abundance ratio. For example, as an evaluation of the adhesion of the printing ink, the gravure ink is solid-printed on the surface of the release layer (C) at an amount of ² g / m ² , and the same surface after drying the ink is JIS-L-0849: 2004. The residual ratio of ink on the surface after 50 times of friction test with a load of 500 g using a Gakushin type friction tester and gold width No. 3 is as good as 60 to 100%, more preferably 80 to 95%. It is clear from some. If the ink residual ratio is less than 60%, the adhesion of the printing ink cannot be said to be sufficient, and the printability cannot be said to be good.

  Moreover, it is preferable that the peeling force with the adhesive of a peeling layer (C) is the range of 0.01-2.0N / 50mm, and it is more preferable that it is the range of 0.1-1.0N / 50mm. . The peeling force is a value determined according to JIS-K-6854-2: 1999 using a commercially available adhesive tape as a reference, as described in detail in the section of (peeling force) described later. When the peeling force exceeds 2.0 N / 50 mm, the force required for peeling of the peelable film tends to increase when the pressure-sensitive adhesive tape or pressure-sensitive adhesive label is used, and the commercial value thereof decreases. When the peeling force is less than 0.01 N / 50 mm, it is not preferable because the residual adhesion rate described later tends to decrease. The peel force can be adjusted by factors such as the degree of the perforated structure of the release layer (C) and the selection of the silicone release agent.

  Moreover, a residual adhesive rate is mentioned as one parameter | index which shows the performance of a peeling layer (C). This is because when the pressure-sensitive adhesive of the pressure-sensitive adhesive tape is brought into contact with the release layer (C) and peeled off, the release agent is removed from the release layer (C), that is, the release agent layer from the resin layer (c3) ( It is quantified that the pressure-sensitive adhesive surface is contaminated with the release agent due to the release of c4) and the adhesive force is lowered. The residual adhesion rate calculated by the method described in detail in the section (Residual adhesion rate) described later is preferably in the range of 70 to 100%, and more preferably in the range of 80 to 100%. When it is less than 70%, it means that the adhesiveness of the silicone release agent to the resin layer (c3) is low, and the adhesive on the opposite surface is contaminated with silicone when processed into an adhesive tape or the like. This is not preferable. The residual adhesion rate can be adjusted by complex factors such as the corona discharge treatment described above, the bleed-out amount of the additive on the surface of the resin layer (c3), and the selection of the silicone release agent.

"Adhesive tape"
In the peelable film of the present invention, an adhesive tape (D) is further provided on the easy-printable layer (A) and rolled up, whereby an adhesive tape excellent in peelability and printability / writing property on the peeled surface is obtained. can get. The present invention includes such an adhesive tape.
"Adhesive layer (D)"
Examples of the pressure-sensitive adhesive that can be used for forming the pressure-sensitive adhesive layer (D) in the present invention include pressure-sensitive adhesives described in pages 20 to 88 of the pressure-sensitive adhesive handbook 3rd edition (issued by Japan Pressure-sensitive Tape Industry Association).
Specific examples of the adhesive include polyisobutylene rubber, butyl rubber, a rubber adhesive obtained by dissolving a mixture thereof in an organic solvent such as benzene, toluene, xylene and hexane, or rosin abietic acid in these rubber adhesives. A blend of tackifiers such as ester, terpene / phenol copolymer, terpene / indene copolymer, or 2-ethylhexyl acrylate / n-butyl acrylate copolymer, 2-ethylhexyl acrylate / ethyl acrylate / methacryl Examples thereof include an acrylic pressure-sensitive adhesive prepared by dissolving an acrylic copolymer having a glass transition point of −20 ° C. or lower such as an acid methyl copolymer in an organic solvent, and an emulsion pressure-sensitive adhesive having the same composition.

The coating amount of the pressure-sensitive adhesive is usually 3 to 40 g / m ² , preferably 10 to 30 g / m ² in terms of solid content. The thickness of the pressure-sensitive adhesive layer (D) after the pressure-sensitive adhesive coating / drying is generally 10 to 50 μm in the case of the acrylic pressure-sensitive adhesive and 80 to 150 μm in the case of the rubber-based pressure-sensitive adhesive. . When the adhesive force between the peelable film on the easy-printable layer (A) side and the pressure-sensitive adhesive is small, before applying the pressure-sensitive adhesive, apply an anchor coating agent on the easy-printable layer (A). It is preferable. Examples of the anchor coating agent include polyurethane, polyisocyanate / polyether polyol, polyisocyanate / polyester polyol / polyethyleneimine, and alkyl titanate. These are generally used as a coating agent by being dissolved in water, an organic solvent such as methanol, ethyl acetate, toluene or hexane. Easily print layer (A) coating amount of the anchor coating agent to the above, usually 0.01-5 g / ^{m 2} by solid content after coating and drying, is preferably from 0.05 to 2 g / ^{m 2} .

In addition, in the present invention, after adjusting the pressure-sensitive adhesive tape at 23 ° C. for 2 weeks, the pressure-sensitive adhesive layer (D) is contact-bonded to the flat SUS304 plate surface, and further 10 g / cm ² load is applied at 23 ° C. Pressure bonding for 1 hour, and then the 180 ° peel strength measured at a peel rate of 300 mm / min using a tensile tester in accordance with JIS-K6854-2: 1999 was taken as the room temperature adhesive strength (N / 50 mm). Was adjusted for 20 hours under the condition of 70 ° C., then cooled for 30 minutes under the condition of 23 ° C., the pressure-sensitive adhesive layer (D) was contact-bonded to the flat SUS304 plate surface, and further 10 g / cm ² under the condition of 23 ° C. After pressure-bonding for 1 hour under load, the 180 ° peel strength measured at a peel rate of 300 mm / min using a tensile tester in accordance with JIS-K6854-2: 1999 was defined as the high temperature adhesive strength (N / 50 mm). , Is 80% to 100% adhesion retention of adhesive layer obtained by the following formula (1) (D), more preferably in the range of 90% to 100%.
Adhesive strength retention rate (%) = high temperature adhesive strength / room temperature adhesive strength × 100 (1)

When the adhesion retention is less than 80%, it means that the adhesiveness between the peelable film and the silicone release agent, that is, the resin layer (c3) and the silicone release agent layer (c4) is insufficient, It is not preferable. In such a case, countermeasures such as the corona discharge treatment described above are required.
The pressure-sensitive adhesive tape of the present invention is obtained by winding an adhesive on the easy-printable layer (A) of the peelable film of the present invention and drying it. When winding the adhesive tape, it is important to wind the tape under an appropriate winding tension so as not to cause wrinkles or sagging. In addition, depending on the type of pressure-sensitive adhesive, it is preferable to perform aging in an oven set at 30 to 50 ° C. after the winding to stabilize the quality during use.

"Adhesive label"
In the peelable film of the present invention, the same pressure-sensitive adhesive layer (D) as described above on the release layer (C), and further by laminating the label upper paper (E) in order, the air release is good, An adhesive label with little curling and which can be re-attached is obtained. The present invention includes such an adhesive label.
"Paper for label (E)"
The label upper paper (E) used in the present invention is mainly made of paper containing natural pulp such as plain paper or coated paper as a main constituent, and thermoplastic resin such as thermoplastic resin film or synthetic paper. Paper containing as a component can be used. In consideration of outdoor use of the adhesive label, it is preferable to use a thermoplastic resin film or synthetic paper from the viewpoint of water resistance of the substrate.

  The thermoplastic resin film used as the label top paper (E) is made of ethylene resin such as high density polyethylene or medium density polyethylene, or polyolefin resin such as propylene resin, polymethyl-1-pentene, ethylene / cyclic olefin copolymer Thermoplastics such as coalescence, nylon-6, nylon-6,6, nylon-6, T and other polyamide resins, polyethylene terephthalate and copolymers thereof, polybutylene terephthalate, polylactic acid, polybutylene succinate, aliphatic polyester, etc. A polyester resin, polycarbonate, atactic polystyrene, syndiotactic polystyrene or the like can be used. As the thermoplastic resin, one type may be selected from the above thermoplastic resins and used alone, or two or more types may be selected and used in combination. Among these thermoplastic resins, it is preferable to use a polyolefin-based resin as a main constituent material from the viewpoints of cost, flexibility of labels, and reattachment.

  The propylene-based resin that can be used in the present invention is a propylene homopolymer, isotactic or syndiotactic and polypropylene having various degrees of stereoregularity, or propylene as a main component, ethylene, A copolymer obtained by copolymerization with an α-olefin such as 1-butene, 1-hexene, 1-heptene, 4-methyl-1-pentene can be used. The copolymer may be a binary system or a ternary system or may be a random copolymer or a block copolymer. When a propylene homopolymer is used as the propylene-based resin, 2 to 25% by weight of a resin having a melting point lower than that of the propylene homopolymer can be used. Examples of such a resin having a low melting point include high-density or low-density polyethylene.

Synthetic paper used as the label upper paper (E) includes the above-described polyolefin resin and at least one of an inorganic filler and an organic filler as a main constituent, and is formed by stretching. These are produced in the same manner as the above-mentioned thermoplastic resin film layer (B), and those added with a stabilizer, a light stabilizer, a dispersant, a lubricant and the like can be used as necessary.
The label upper paper (E) used in the present invention is the same as the thermoplastic resin film layer (B) in consideration of wrinkle prevention at the time of adhesive label processing, curl prevention at the time of use, and recyclability at the time of disposal. It is preferable that it is a main raw material, and also it is preferable to manufacture by the same manufacturing method.
When the adhesive label of the present invention is used, for example, by printing, by bonding the thermoplastic resin film (thermoplastic resin film layer (B) and label paper (E)) manufactured by the same main raw material and the same manufacturing method. It becomes easy to reduce curl at the time.

As a more specific numerical target, thermoplasticity measured according to JIS-K-7133: 1999 is used to prevent curling due to the thermal history of the pressure-sensitive adhesive label of the present invention (for example, thermal drying after printing, UV drying). Ratio obtained from the heat shrinkage rate of the resin film layer (B) and the heat shrinkage rate of the label paper (E) (heat shrinkage rate (%) of the label paper (E) / thermoplastic resin film layer ( The thermal contraction rate (%) of B) is preferably in the range of 0.7 to 1.3. When the heat shrinkage ratio is less than 0.7, it is not preferable because when the pressure-sensitive adhesive label is dried after printing, it largely curls to the peelable film side. On the contrary, when the heat shrinkage ratio exceeds 1.3, when the adhesive label is dried after printing, it is unfavorably curled to the label upper paper (E) side.
In addition, the label top paper (E) used in the present invention has an appropriate tensile strength and tensile modulus in conjunction with the selection of the pressure-sensitive adhesive layer (D) so that reattachment after adhesion to the adherend becomes easier. It is preferable to have.

Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples and Test Examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in each example and comparative example can be appropriately changed without departing from the present invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.
The details of the materials used in each example and comparative example are shown in Table 1. “MFR” in the table means melt flow rate. Moreover, the kind and compounding quantity (weight%) of the material used in manufacture of the thermoplastic resin film layer (B) of each Example and a comparative example were described in Table 2, and stretching conditions and the basic weight of the layer were described in Table 3. . The material names described in Tables 2, 5, and 6 correspond to the material names described in Table 1.

(Comparative Example 1)
A compound having the composition shown in Table 2 was melt-kneaded with an extruder set at 250 ° C. as a base layer (a), extruded into a sheet form from a die, and then cooled to 70 ° C. with a cooling device. A stretched film was obtained. This unstretched film was heated to the stretching temperature shown in Table 3, and then stretched in the longitudinal direction by stretching between rolls to obtain a longitudinally uniaxially stretched film.
Next, a compound having the composition shown in Table 2 was melt-kneaded as a surface layer (ii) with an extruder set at 250 ° C., extruded into a sheet form from a die, and laminated on both the front and back surfaces of the longitudinal uniaxially stretched film. Then, this was passed between nip rolls composed of a smooth metal roll and a rubber roll (backup roll), and each layer was pressure bonded to obtain a laminated film (surface layer (I) / base layer (A) / surface layer (I)). . In this example, the surface layer (A) on the surface side corresponds to the resin layer (c3).

After heating this laminated film to the stretching temperature shown in Table 3, it was stretched 9 times in the transverse direction using a tenter stretching machine, and further subjected to an annealing treatment at a temperature 20 ° C. higher than the stretching temperature (2). A uniaxially stretched / biaxially stretched / uniaxially stretched thermoplastic resin film layer (B) was obtained.
Furthermore, the both sides of this thermoplastic resin film layer (B) are subjected to corona discharge treatment with an intensity of 40 W · min / m ² , and the coating solution shown in Table 2 is applied to the back side of the layer (B) by a gravure coating method. Was applied and dried to provide an easily printable layer (A). Furthermore, the silicone release agent liquid shown in Table 2 was applied to the surface side of the layer (B) by a gravure coating method and dried to provide a silicone release agent layer (c4) to obtain a release film.

Example 1
When the laminated film of Comparative Example 1 was obtained, the compound having the composition shown in Table 2 was melt kneaded with an extruder set at 250 ° C. as the surface layer (A), and extruded into a sheet form from a die. Laminated on the surface side of a uniaxially stretched film, this is passed between an embossing roll made of a metal roll (specifications are listed in Table 3) and a nip roll made of a rubber roll, and pressure-bonded, and the surface side of the layer (B) A peelable film was obtained by the same production method as in Comparative Example 1 except that a laminated film having a concave structure was used. The performance evaluation results as a peelable film are shown in Table 4.

(Examples 2-15, Comparative Examples 2-14)
A peelable film was obtained by the same production method as in Example 1 except that the composition having the composition shown in Table 2 and the production conditions shown in Table 3 were changed. The performance evaluation results as a peelable film are shown in Table 4.

(Example 16, comparative example 15)
A compound having the composition shown in Table 2 was melt-kneaded with an extruder set at 250 ° C. as a base layer (a), extruded into a sheet form from a die, and then cooled to 70 ° C. with a cooling device. A stretched film was obtained.
Next, a compound having the composition shown in Table 2 was melt-kneaded with an extruder set at 250 ° C. as a surface layer (ii), extruded into a sheet form from a die, and this was laminated on the back side of the unstretched film, This was passed between nip rolls composed of a smooth metal roll and a rubber roll (backup roll), and both layers were pressure-bonded. Then, a compound having the composition shown in Table 2 was added to the surface layer (I) (resin layer (c3 )) Is melt-kneaded with an extruder set at 250 ° C., extruded into a sheet form from a die, laminated on the surface side of the unstretched film, and this is an embossed roll made of a metal roll (specifications are shown in Table 3). The laminated film having a concave structure on the surface side was obtained by passing between a nip roll comprising a rubber roll and a rubber roll.
Furthermore, both sides of this laminated film were subjected to a corona discharge treatment with an intensity of 40 W · min / m ² , and the coating solution shown in Table 2 was applied to the back side of the film by a gravure coating method and dried. An easily printable layer (A) was provided. Furthermore, the silicone release agent liquid shown in Table 2 was applied to the surface side of the film by a gravure coating method and dried to provide a silicone release agent layer (c4) to obtain a release film. The performance evaluation results as a peelable film are shown in Table 4.

(Examples 17 to 19, Comparative Examples 16 and 17)
The adhesive (adhesive 1) shown in Table 5 was applied to the easy-printable layer (A) side of the peelable film produced in Examples 1, 8, 9 and Comparative Examples 2, 8 by a comma coater method. The adhesive tape was obtained by winding the peelable film after drying in a heat oven. Details of the manufacturing conditions are shown in Table 5. Furthermore, the performance evaluation result of this adhesive tape is also shown in Table 5.

(Example 20)
When obtaining the peelable film of Comparative Example 1, the same manufacturing method as Comparative Example 1 was used except that the same coating agent solution as that of the back side was applied to the surface side of the layer (B). An upper label paper (E) having an easily printable layer (A) was obtained. This is not provided with a silicone release agent layer (c4).
Next, the adhesive (adhesive 2) shown in Table 6 was applied to the release layer (C) side of the peelable film obtained in Example 1 by a comma coater method, dried in a hot oven, and then used for the label. An adhesive label was obtained by pasting the upper paper (E). Details of the manufacturing conditions are shown in Table 6. Furthermore, the performance evaluation result of this adhesive label is also shown in Table 6.

(Example 21)
In Example 16, after the corona discharge treatment was applied to both surfaces of the laminated film with an intensity of 40 W · min / m ² , the same coating agent solution as that on the back side was applied to the front side of the film. From the same production method as in Example 16, an upper label paper (E) having an easily printable layer (A) on both the front and back surfaces was obtained. This is not provided with a silicone release agent layer (c4).
Next, the adhesive (adhesive 2) shown in Table 6 was applied to the release layer (C) side of the peelable film obtained in Example 16 by a comma coater method, dried in a thermal oven, and then used for the label. An adhesive label was obtained by pasting the upper paper (E). Details of the manufacturing conditions are shown in Table 6. Furthermore, the performance evaluation result of this adhesive label is also shown in Table 6.

(Example 22, Comparative Examples 18-21)
A pressure-sensitive adhesive label was obtained in the same manner as in Example 21 except that the peelable film shown in Table 6 and the label top paper were used. The performance evaluation results of the pressure-sensitive adhesive label are also shown in Table 6.

(Comparative Example 22)
In order to reproduce the peelable film of Example 1 of Japanese Patent No. 3950115, an adhesive label was prepared by the following method.
That is, a grooved embossing roll having an embossing interval of 126 μm, an embossing height of 16 μm, a groove upper side length of 34 μm, and a groove bottom surface length of 17 μm is heated to 110 ° C. and used. The polyethylene-treated paper processed with silicone was embossed to obtain a peelable film.
Using the peelable film, an adhesive label was prepared using the adhesive shown in Table 6 and an upper label paper. The performance evaluation results of the pressure-sensitive adhesive label are also shown in Table 6.

(Comparative Example 23)
An adhesive label was prepared in the same manner as in Comparative Example 22 except that the peelable film used in Comparative Example 22 was used and the upper printing paper was changed to the upper labeling paper shown in Table 6. Table 6 shows the performance evaluation results of the pressure-sensitive adhesive label.

[Test example]
(Surface resistivity)
In accordance with JIS-K-6911: 1995, the peelable film was conditioned for 2 hours or more in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, and then the surface specific resistance of the surface of the easily printable layer (A) of the film The value (Ω / m ² ) was measured using an insulation meter (model number: DSM-8103, manufactured by Toa Denpa Kogyo Co., Ltd.).
(Surface roughness)
In accordance with JIS-B-0601: 1994, the surface average roughness (Ra) (μm) of the surface of the easily printable layer (A) of the peelable film is measured with a three-dimensional roughness measuring device (model number: SE-3AK, ( Measurement was performed using a Kosaka Laboratory Co., Ltd.) and an analyzer (model number: SPA-11, manufactured by Kosaka Laboratory Co., Ltd.).

(Water contact angle)
Based on JIS-R-3257: 1999, the water contact angle (°) on the surface of the easily printable layer (A) of the peelable film is measured with a contact angle measuring device (model number: CA-D, manufactured by Kyowa Interface Science Co., Ltd.). ) Was used, and pure water was dropped on the surface of the layer (A) and measured from the water contact angle after 1 minute. This measurement was performed 10 times (replaced with an unmeasured film whose surface was not wet for each measurement), and the average value of the measured values was obtained as the water contact angle.
(Ink residual ratio)
2 g of solvent-based gravure ink (model number: Pan-Echo Indigo, manufactured by Toyo Ink Manufacturing Co., Ltd.) is used on the surface of the release layer (C) of the peelable film using a gravure aptitude tester (model number: NO.2270, manufactured by Kumagai Riki Co., Ltd.). A solid print pattern with 175 gravure lines was printed at an amount of / m ² and left to dry at room temperature for 3 days to obtain a print sample. According to JIS-L-0849: 2004, the printed sample was attached to a Gakushin friction tester (manufactured by Suga Test Instruments Co., Ltd.), and the printed surface was subjected to a friction test 50 times with a load of 500 g using a gold width No. 3. The Macbeth color density before and after rubbing was measured with a Macbeth densitometer (manufactured by Macbeth Co., Ltd.), and the ink residual ratio was determined from the following formula (2).
Ink residual ratio (%) = (Macbeth density after rubbing) ÷ (Macbeth density before rubbing) × 100
... (2)

(Ink adhesion)
1000 sheets of a peelable film of a chrysanthemum half version (636 mm × 470 mm) were prepared.
Next, using an offset printing machine (model number: OF-4, manufactured by Mitsubishi Heavy Industries) and UV ink (model number: BC-161 Sumi, manufactured by T & K TOKA) in an environment of a temperature of 23 ° C. and a relative humidity of 30%, peeling A pattern containing 50% halftone dots and 100% solids was continuously printed on the surface of the easily printable layer (A) of the adhesive film at a speed of 6000 sheets / hour. Then, adhesive tape (model number: cello tape (registered trademark) CT-18, manufactured by Nichiban Co., Ltd.) is pasted by hand after the ink is dried by irradiating ultraviolet rays having an intensity of 100 mj / cm ^{2 with} a UV irradiator. The condition when worn and peeled by hand was observed and evaluated according to the following criteria.
○: The ink is hardly peeled off, and the material of the peelable film may be destroyed.
Δ: There is resistance when peeling off, but most of the ink is peeled off, causing a problem in practical use.
X: All the ink peeled off, and there was almost no resistance when peeling off.

(Halftone dot reproducibility)
The 50% halftone dot portion of the peelable film printed by the ink adhesion evaluation was enlarged and magnified at a magnification of 50 using a digital microscope (model number: VH-8000, manufactured by Keyence Corporation), and the screen was observed.
Evaluation was made according to the following criteria.
○: There are no more than 5 missing dots in the screen.
Δ: There are 6 or more halftone dots and 20 or less in the screen.
X: There are 21 or more halftone dots in the screen.
(Heat shrinkage)
The thermoplastic resin film layer (B) and the label paper (E) used in Examples 20 to 22 and Comparative Examples 19 to 24 are cut off at 10 cm square, and the length of four sides is a digital reader (model number: DR- 565D, manufactured by Dainippon Screen Mfg. Co., Ltd.), and then suspended and heated in an oven (model number: DN-43, manufactured by Yamato Chemical Co., Ltd.) set at 100 ° C. for 2 hours, and four sides after oven heating The length was measured again with a digital reader, and the average value of the dimensional change rate was calculated as the heat shrinkage rate (%).

(Additive bleed-out amount)
The peelable film is cut off at a 10 cm square, and two sheets are placed on the side of the 500 ml beaker with the release layer (C) side facing inward. Pour 500 ml of chloroform into this beaker and stir with a stirrer for 2 minutes to dissolve the surface bleed-out product in chloroform. After concentrating this chloroform extract 10 times (50 ml) using an evaporator, solid content such as filler and silicone cured product is once removed with glass fiber filter paper (model number: GF / F, manufactured by Whatman). The solvent was completely vaporized again with an evaporator, and the additive that had bleed out to the surface of the release layer (C) was extracted as a solidified product. From the weight of the solidified product and the surface area of the sample, the additive bleed-out amount (mg / m ² ) per certain area was calculated.

(Peeling layer (C) surface shape)
With respect to the release layer (C) surface shape of the peelable film, the non-contact 3D surface shape roughness measuring instrument (model number: NewView 5010, manufactured by Zygo Co., Ltd.) was used to measure the surface direction 3D surface shape. : 2 mm × 2 mm, objective lens: 20 times, measurement was performed under the condition of cutting a wavelength of 14 μm or less, and the following four points were analyzed using analysis software (model number: MetroPro, manufactured by Zygo Corporation).
1) Distance between perforated structures (c2) (film running direction / perpendicular direction)
2) Area ratio of flat surface (c1) occupying release layer (C) 3) Depth from flat surface (c1) to perforated structure (c2) bottom 4) Perforated structure (c2) sectional shape and diagonal ratio ( (Long diameter / short diameter)
In addition, the surface uneven shape of the embossing roll used for the production of the peelable film is transferred from the embossing roll to a replica film (manufactured by Oken Shoji Co., Ltd.), and the evaluations 1) to 4) above are performed in the same manner as the peelable film. Went.

(Silicone release agent coating amount distribution)
In the release layer (C) of the peelable film, the Si amount (s1) observed on the flat surface (c1) and the Si amount (s2) observed on the perforated structure (c2) portion are the row time type secondary ions. Using a mass spectrometer (TOF-SIMS), the measurement was performed as the Si positive ion intensity at each location. The measurement conditions are as follows.
Model name: IONTOF TOF-SIMS IV
Primary ion: Bi ³⁺ , acceleration voltage 25 kV, irradiation current 0.2 pA
Secondary ion: Positive ion collection, analysis area 2mm square, integration time 209sec
The silicon abundance ratio (s1 / s2) was obtained from the ratio between the observed Si amount (s1) and the Si amount (s2).

(Love-off evaluation)
In the release layer (C) of the peelable film, the adhesion of the silicone release agent layer (c4) on the resin layer (c3) was qualitatively evaluated from the following methods and standards.
That is, after the surface of the release layer (C) of the release film was rubbed strongly 10 times with the index finger, the surface was rubbed and non-rubbed with a red oily magic (model number: Magic Ink Thick, Teranishi Chemical Co., Ltd.). The chemical surface was written, and the degree of ink repelling was judged visually.
○: The ink repelling degree of the rubbed surface and the non-rubbed surface is the same, and the silicone release agent is strongly adhered.
Δ: The degree of ink repellency on the rubbed surface is slightly weak and a difference is observed, so the adhesion of the silicone release agent is slightly weak and a part is peeled off.
×: A large difference was observed in the ink repellency between the rubbed surface and the non-rubbed surface, and the ink repellency was not felt on the rubbed surface, so the adhesion of the silicone release agent was weak and completely peeled off. .

(Peeling power)
In accordance with JIS-K-6854-2: 1999, a commercially available adhesive tape (model number: 31B, manufactured by Nitto Denko Corporation, tape width 25 mm) is bonded to the release layer (C) of the peelable film, and 10 g / cm. ^After applying ² loads and allowing to stand for 1 hour in a constant temperature room at 23 ° C., the peelable film and the adhesive tape of the sample were pulled using a tensile tester (model number: Autograph AGS-5KND, manufactured by Shimadzu Corporation). Then, the strength at the time of 180 ° peeling was measured at a peeling speed of 300 mm / min, and this was taken as the peeling force.

(Residual adhesion rate)
After the adhesive tape after the peeling force measurement used in the above peeling force measurement was contact-bonded to a flat SUS304 stainless steel plate and left at 23 ° C. in a constant temperature room for 1 hour under a load of 10 g / cm ² and adhered. The 180 ° peel strength between the pressure-sensitive adhesive tape and the SUS plate is measured under the same conditions as the above-described peel force measurement, and the blank pressure-sensitive adhesive tape is similarly contact-bonded to a flat SUS304 stainless steel plate, and a load of 10 g / cm ^{2 is} applied. And then left in a constant temperature room at 23 ° C. for 1 hour to make a close contact, and when the 180 ° peel strength between the pressure-sensitive adhesive tape and the SUS plate is measured under the same conditions as the above peel force measurement, the residual adhesion rate is expressed by the following formula (3 ).
Residual adhesion rate (%) = peel strength after measurement of peel force / peel strength of blank × 100 (3)

(Adhesive strength and adhesive strength retention)
After adjusting the pressure-sensitive adhesive tapes obtained in Examples 17 to 19 and Comparative Examples 17 and 18 under the condition of 23 ° C. for 2 weeks, the pressure-sensitive adhesive layer (D) was contact bonded to the flat SUS304 plate surface, and further 23 ° C. After pressure-bonding for 1 hour under a load of 10 g / cm ² under the conditions, the 180 ° peel strength measured at a peel rate of 300 mm / min using a tensile tester in accordance with JIS-K6854-2: 1999 was measured at room temperature adhesive force ( N / 50mm)
Separately, the pressure-sensitive adhesive tape was adjusted at 70 ° C. for 20 hours, then cooled at 23 ° C. for 30 minutes, and the pressure-sensitive adhesive layer (D) was contact bonded to the flat SUS304 plate surface. After pressure bonding for 1 hour under a load of / cm ² , 180 ° peel strength measured at a peel rate of 300 mm / min using a tensile tester in accordance with JIS-K6854-2: 1999 is a high-temperature adhesive force (N / 50 mm). When
The adhesive strength retention was calculated by the following formula (1).
Adhesive strength retention rate (%) = high temperature adhesive strength / room temperature adhesive strength × 100 (1)

(Label curl judgment)
The adhesive labels obtained in Examples 20 to 22 and Comparative Examples 19 to 24 were cut off at 10 cm square, and the samples were suspended in an oven (model number: DN-43, manufactured by Yamato Chemical Co., Ltd.) set at 60 ° C. for 2 hours. After heating, place the sample on a horizontal laboratory table in a room temperature environment so that the convex curl is on the lower side, and after standing for 30 minutes, measure the amount of curl lifted from the table at the four corners of the sample. Judgment was performed from the average value according to the following criteria.
○: The curl average amount is within 5 mm and good. △: The curl average amount exceeds 5 mm and within 10 mm. Bad: The curl average amount exceeds 10 mm.

(Air leak appearance judgment)
The adhesive labels obtained in Examples 20 to 22 and Comparative Examples 19 to 24 were cut off at 30 cm square, and bonded to a glass plate using a 2 kg roller.
The degree of air loss of the label paper after pasting was determined from the appearance according to the following criteria.
○: No blister (blowing due to air entrainment), good air removal △: 1-2 blisters are found, poor air removal ×: 3 or more blisters are seen, poor air removal

(Re-paste suitability)
The corner portion of the label upper paper used in the above-described air leakage appearance determination was pulled up by hand, pulled up a 5 cm square portion from the glass plate, and then bonded to the glass plate again. Judgment was made based on the following criteria from the positional deviation of the label paper before and after re-sticking.
○: Position deviation is within 5 mm and good △: Position deviation is over 5 mm and within 10 mm and defective x: Position deviation exceeds 10 mm and defective

Claims (15)

A peelable film having a laminate structure including an easily printable layer (A), a thermoplastic resin film layer (B), and a release layer (C) in this order,
The surface of the release layer (C) has a flat surface (c1) and a perforated structure (c2);
When measuring the three-dimensional surface shape in the planar direction using a non-contact three-dimensional surface shape roughness measuring instrument under conditions that cut the wavelength of measurement area: 2 mm × 2 mm, objective lens: 20 times, 14 μm or less ,
The perforated structure (c2) on the surface of the release layer (C) is regularly arranged in at least one direction at intervals of 50 to 400 μm,
The area ratio of the flat surface (c1) occupying the surface of the release layer (C) is in the range of 5 to 40%,
The depth from the flat surface (c1) to the bottom of the perforated structure (c2) is in the range of 5 to 20 μm,
The cross-sectional shape of the perforated structure (c2) viewed in the direction parallel to the flat surface (c1) is at least one of a rhombus and an ellipse;
And the diagonal ratio (major axis / minor axis) of the same cross-sectional shape is the range of 3-10, The peelable film characterized by the above-mentioned.   A release layer (C) is a resin layer (c3) in which a flat surface (c1) and a perforated structure (c2) are formed with a polyolefin resin as a main component, and a silicone release provided on the resin layer (c3) by coating. It forms from an agent layer (c4), The peelable film of Claim 1 characterized by the above-mentioned. The resin layer (c3) is made of a resin composition containing a thermoplastic resin and an additive, and the bleedout amount of the additive from the resin layer (c3) to the surface of the same layer is 10 to 200 mg / m ^2. The peelable film according to claim 2. Before the silicone release agent layer (c4) is provided on the resin layer (c3), the surface of the resin layer (c3) is subjected to corona discharge treatment with a discharge density of 10 to 50 W · min / m ^2. Item 4. The peelable film according to item 2 or 3.   In the release layer (C), the silicon abundance ratio (s1 / s2) obtained from the Si amount (s1) observed on the flat surface (c1) and the Si amount (s2) observed on the perforated structure (c2) Is in the range of 0.8 to 1.2, the peelable film according to any one of claims 2 to 4. The surface of the release layer (C) is solid-printed with gravure ink in an amount of ² g / m ² , and the dried surface is compliant with JIS-L-0849: 2004 using a Gakushin type friction tester and No. 3 The peelable film according to any one of claims 1 to 5, wherein an ink residual ratio after 50 times friction test with a load of 500 g is 60 to 100%.   The peelable film according to any one of claims 1 to 6, wherein the thermoplastic resin film layer (B) contains at least one of a polyolefin-based resin and an inorganic or organic filler as a main constituent material. The easily printable layer (A) is a layer provided by coating on the thermoplastic resin film layer (B), contains a polymer antistatic agent, and measured according to JIS-K6911: 1995 The specific resistance value is 10 ⁸ to 10 ¹³ Ω / m ² , the water contact angle of the surface measured according to JIS-R3257: 1999 is 60 to 100 °, and according to JIS-B0601: 1994. The peelable film according to claim 1, wherein the measured arithmetic average surface roughness Ra is 0.2 to 0.9 μm.   A pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer (D) provided on the easily printable layer (A) of the peelable film according to claim 1.   The peelable film is in the form of a roll wound up continuously in the longitudinal direction, and while being unwound, an adhesive is applied onto the easy-printable layer (A) and dried to form an adhesive layer (D) The pressure-sensitive adhesive tape according to claim 9, wherein the pressure-sensitive adhesive tape is rolled up again after being wound. After adjusting the pressure-sensitive adhesive tape at 23 ° C. for 2 weeks, the pressure-sensitive adhesive layer (D) was contact bonded to the surface of a flat SUS304 plate, and further pressure-bonded for 1 hour under a load of 10 g / cm ² under the condition of 23 ° C. Thereafter, the 180 ° peel strength measured at a peel rate of 300 mm / min using a tensile tester in accordance with JIS-K6854-2: 1999 was the room temperature adhesive force (N / 50 mm),
Separately, the pressure-sensitive adhesive tape was adjusted at 70 ° C. for 20 hours, then cooled at 23 ° C. for 30 minutes, and the pressure-sensitive adhesive layer (D) was contact bonded to the flat SUS304 plate surface. After pressure bonding for 1 hour under a load of / cm ² , 180 ° peel strength measured at a peel rate of 300 mm / min using a tensile tester in accordance with JIS-K6854-2: 1999 is a high-temperature adhesive force (N / 50 mm). The pressure-sensitive adhesive tape according to claim 10, wherein the adhesive strength retention determined by the following formula (1) is in the range of 80 to 100%.
Adhesive strength retention rate (%) = high temperature adhesive strength / room temperature adhesive strength × 100 (1)   A pressure-sensitive adhesive label in which a pressure-sensitive adhesive layer (D) and a label paper (E) are provided in this order on the release layer (C) of the peelable film according to claim 1, wherein JIS-K -7133: The ratio of the heat shrinkage rate of the thermoplastic resin film layer (B) measured in accordance with 1999 and the heat shrinkage rate of the label top paper (E) is in the range of 0.7 to 1.3. Adhesive label characterized by.   The pressure-sensitive adhesive label according to claim 12, wherein the label upper paper (E) is a resin film containing a polyolefin resin as a main constituent material.   14. The pressure-sensitive adhesive according to claim 13, wherein the label upper paper (E) is a synthetic paper containing a polyolefin-based resin and at least one of an inorganic and organic filler as a main constituent material and stretched and formed. label.   The pressure-sensitive adhesive label according to claim 12, wherein the label upper paper (E) is natural pulp paper.

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