JP2012214005A - Water-absorbable and easily releasable film, and wall paper or label using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-absorbable and easily releasable film that can easily apply to a matter to be stuck through an adhesive dispensing with a back-up material, can provide a condition easy to again stick on the surface of the matter to be stuck without leaving concavity and convexity after releasing from the matter to be stuck, and can easily recover the released film in a state allowing to be recycled as a material.SOLUTION: The water-absorbable and easily releasable film has a structure obtained by laminating a water-absorbable and easily releasable layer (B) on a base layer (A) including a thermoplastic resin. The water-absorbable and easily releasable layer (B) includes: 30-60 wt.% of a blended material of a crystalline polypropylene resin and a thermoplastic resin immiscible with the crystalline polypropylene resin; and 40-70 wt.% of an inorganic fine powder the surface of which is made hydrophilic by a surface treatment agent, and is stretched at least one axial direction wherein 100 pts.wt. of the crystalline polypropylene resin is blended with 105-300 pts.wt. by weight of the immiscible thermoplastic resin.

Description

  The present invention relates to a water-absorbable easily peelable film useful as a wallpaper that can be bonded to a building material or a label that can be bonded to a glass or resin bottle via an adhesive. In particular, it is easy to apply to a building material or the like directly through an adhesive without using a natural paper backing material, and to a bottle or the like. Since the water-absorbing easily peelable layer remains on the surface side of the adherend, the adherend after peeling does not leave large irregularities on the surface, and the surface is in a state capable of absorbing liquid, so it can be reattached. Easy. Further, the film itself can be easily peeled in a recyclable state, which is useful for reducing waste.

  2. Description of the Related Art Conventionally, polyolefin-based films and calender-molded films mainly composed of vinyl chloride (PVC) resin have been used as base materials for labels of containers such as wallpaper and bottles or resin bottles as architectural decoration materials. Usually, these resin films alone are difficult to absorb the adhesive, and therefore, a water-absorbing resin layer is laminated on the bonding side (for example, Patent Document 1), or backing processing of other materials is performed.

A film on which these water-absorbing layers are laminated can be attached to an adherend with a solvent-based or water-based adhesive. However, when these water-absorbing layers are laminated, the peeled-off surface is uniform because part of the water-absorbing layer left on the adherend side remains or peels off the adherend side when peeled off from the adherend. However, when the wallpaper and the label are reapplied on the adherend side, the unevenness of the foundation is raised on the surface, and the appearance is deteriorated, so that there is a problem that the reattachment cannot be performed.
Further, there is a problem that the film peeled off when the wallpaper and the label are replaced cannot be recycled as a material. In order to recycle the peeled film, the film and the adhesive must be separated or the film and the backing material must be separated, but these are usually difficult to implement because they are firmly bonded.

  For this reason, any type of wallpaper or label that is not recycled is mixed with other materials, causing thermal decomposition and generating foreign matter, and the flow characteristics of the resin fluctuate greatly. This is a major problem and makes material recycling itself difficult.

  In order to solve these problems, a wallpaper and a label that have been devised so that the resin material and the backing material can be separated have been proposed. For example, a wallpaper in which a PVC resin layer is provided with a coating layer mainly composed of a binder containing a water-soluble polymer and a vinyl chloride-based or vinyl acetate-based synthetic resin as a backing, immersed in warm water or an alkaline aqueous solution, A PVC and backing material that can be separated by stirring (for example, Patent Document 2), or a PET film or a PP film laminated between the backing material and a foamed PVC base material (for example, a patent) Document 3) has been proposed. However, since these methods increase the number of steps of separating the backing material using chemicals, there are problems such as an increase in the cost required for recycling and a reduction in the quality of the recycled resin material, which has not been put into practical use. For this reason, most of the wallpaper and labels that have been peeled off are disposed of by landfill or incineration, and are not recycled as resin materials. This is contrary to recent market demands.

  A printable surface layer containing a thermoplastic resin, an inorganic fine powder and / or an organic filler as one that can be attached to an adherend such as a wall or board via an adhesive without using a backing material ( A back surface layer (B) containing a thermoplastic resin containing a hydrophilic thermoplastic resin and a surface-treated inorganic fine powder is laminated on the back surface of A), and the peel strength of the back surface layer (B) is 10 to 200 g. An easily peelable multilayer resin stretched film characterized by / cm is proposed (Patent Document 4). In this document, the back surface layer (B) is 10-30 wt% crystalline polypropylene resin, 2-10 wt% hydrophilic resin, 13-25 wt% thermoplastic elastomer, and the surface is hydrophilized. The aspect which laminated | stacked the layer containing 45 to 65 weight% of inorganic fine powder on the base layer is described concretely. These aspects are preferable in that they can be attached to an adherend via an adhesive without using a backing material, but when peeled from the adherend, the back layer (B) Instability of fracture propagation in the surface, unevenness remains on the adherend surface, hindering re-pasting, and in some cases, the fracture propagation of the back layer (B) may reach the surface layer, There was a need for improvement.

JP 2004-347658 A JP-A-6-173200 JP 11-293600 A JP 2002-200707 A

  An object of the present invention is to solve these problems of the prior art. That is, the present invention does not require a backing material, and has excellent workability to building materials such as walls and boards or excellent applicability to bottles and bottles via an adhesive. When peeled from the adherend, the surface of the adherend does not leave any unevenness and it is easy to re-attach, and the peeled wallpaper and label can be easily recovered in a material-recyclable state. It was an issue to provide.

  As a result of diligent studies to achieve these problems, the present inventors can provide a water-absorbable easily peelable film having desired characteristics by forming a laminated resin film having a specific layer structure. As a result, the present invention has been completed. That is, the present invention is a water-absorbable easily peelable film comprising a laminated resin film of a base layer (A) and a water-absorbable easily peelable layer (B), wherein the base layer (A) contains a thermoplastic resin, (B) 30 to 60% by weight of a crystalline polypropylene resin and a blend of thermoplastic resin that is incompatible with the crystalline polypropylene resin, and inorganic fine powder 40 to 70 whose surface is hydrophilized with a surface treatment agent In the blend, in the thermoplastic polypropylene resin incompatible with the crystalline polypropylene resin at a ratio of 105 to 300 parts by weight with respect to 100 parts by weight of the crystalline polypropylene resin, and The water-absorbable easily peelable layer (B) relates to a water-absorbable easily peelable film characterized by being stretched in at least one axial direction (see FIG. 1).

The crystalline polypropylene resin preferably has a crystallinity of 65% or more.
The thermoplastic resin incompatible with the crystalline polypropylene resin is selected from the group consisting of a polyethylene resin, a styrene resin, a cyclic polyolefin resin, an ethylene-cyclic olefin copolymer resin, a polyamide resin, a polyester resin, and a polycarbonate. It is preferably at least one resin.

The surface treatment agent is preferably a surface treatment agent selected from the group consisting of a water-soluble anionic surfactant, a water-soluble cationic surfactant, and a water-soluble nonionic surfactant.
It is preferable that the water-absorbable easily peelable layer (B) further contains 0.5 to 30 parts by weight of a dispersant for inorganic fine powder with respect to 100 parts by weight of the surface-treated inorganic fine powder. It is preferably at least one of polyolefin and silanol-modified polypropylene.
The easily absorbable release layer (B) may further contain 0.1 to 30% by weight of at least one of an inorganic fine powder and an organic fine powder whose surface is not hydrophilized.

The water-absorbable easily peelable layer (B) preferably has a transfer amount of distilled water measured by “Japan TAPPI No. 51-2000” of 1 to 20 ml / m ² . The water-absorbable easily peelable film can be attached to an adherend by applying a water-based adhesive on the water-absorbable easily peelable layer (B) side.
Moreover, it is preferable that the peeling strength at the time of peeling a laminated resin film from a to-be-adhered body is 50-180 gf / 18mm after sticking this laminated resin film to this to-be-adhered body. The mechanism for peeling the laminated resin film from the adherend proceeds by cohesive failure in the water-absorbing easily peelable layer (B). As a result, a part of the water-absorbing easily peelable layer (B) remains on the surface of the adherend, and this residue can also absorb the liquid on the surface of the adherend after film peeling.
The base layer (A) may have a multilayer structure.

The water-absorbing easily peelable film may be provided with a concealing layer (C) as necessary. The masking layer (C) is a technique such as black printing or gray printing on the surface of the water-absorbing easily peelable layer (B), adding a masking pigment to the base layer (A), or inserting black printing between the base layers (A). Those formed by the above are preferred.
A coating layer (D) may be further laminated on the surface of the base layer (A) in order to cope with various printing methods.
The present invention can be used as a wallpaper or a label by applying a water-based adhesive to the water-absorbing and easy-peeling layer (B) side of the water-absorbing and easy-releasing film.

  The water-absorbable easily peelable film of the present invention can be easily attached to an adherend such as a building material or a container via an adhesive without requiring a backing material. Moreover, since it does not leave an unevenness | corrugation on the to-be-adhered body surface when peeling from these to-be-adhered bodies, it can re-paste from there further easily. Furthermore, the film (wallpaper or label) peeled off from the adherend has an advantage that it can be easily recovered in a state where material recycling is possible.

It is sectional drawing which shows the layer structure of the water absorption easily peelable film of this invention. It is sectional drawing which shows the layer structure of the water-absorbing easily peelable film of an Example.

  The water-absorbing easily peelable film of the present invention will be described in detail below. As described above, the laminated film of the present invention is composed of a base layer (A) and a water-absorbable easily peelable layer (B), and may be provided with a water-based adhesive, a solvent-based adhesive, and a pressure-sensitive adhesive as necessary. Pattern paper and other laminated films may be provided. 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.

[Base layer A]
The base layer (A) contains a thermoplastic resin, and its own strength is higher than the strength of a water-absorbing easily peelable layer (B) described later, and when it is peeled off with the (A) layer, the inside itself is ruptured. It has strength that does not. The base layer (A) may be transparent, translucent, or opaque.
The type of the thermoplastic resin used for the base layer (A) is not particularly limited. For example, polyolefin resins such as high density polyethylene, medium density polyethylene, low density polyethylene, propylene resin, polymethyl-1-pentene, ethylene-cyclic olefin copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer Polymers, functional group-containing polyolefin resins such as maleic acid-modified polyethylene and maleic acid-modified polypropylene, polyamide resins such as nylon-6 and nylon-6,6, polyethylene terephthalate and copolymers thereof, polybutylene terephthalate, polybutylene Thermoplastic polyester resins such as succinate, polylactic acid and aliphatic polyester, polycarbonate, atactic polystyrene, syndiotactic polystyrene and the like can be used. Among these thermoplastic resins, it is preferable to use a polyolefin resin excellent in processability and a functional group-containing polyolefin resin. More specific examples of polyolefin resins include homopolymers of olefins such as ethylene, propylene, butylene, butadiene, isoprene, chloroprene, methyl-1-pentene, cyclic olefin, and two or more of these olefins. And a copolymer.

  A more specific example of the functional group-containing polyolefin resin is a copolymer of a functional group-containing monomer copolymerizable with the olefins. Such functional group-containing monomers include styrenes such as styrene and α-methylstyrene, vinyl acetate, vinyl alcohol, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl laurate, vinyl stearate, vinyl benzoate. , Vinyl esters of carboxylic acid such as vinyl butylbenzoate and vinyl cyclohexanecarboxylate, acrylic acid, methacrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclope (Meth) acrylic acid esters such as tanyl (meth) acrylate, (meth) acrylamide, and N-metalol (meth) acrylamide ((meth) acrylic acid ester refers to acrylic acid ester and methacrylic acid ester), methyl vinyl ether, Particularly representative are vinyl ethers such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, benzyl vinyl ether, and phenyl vinyl ether. From these functional group-containing monomers, one or two or more types appropriately selected and polymerized can be used as necessary. Furthermore, these polyolefin resins and functional group-containing polyolefin resins can be used after being graft-modified if necessary.

  A known technique can be used for graft modification. Specific examples include graft modification with an unsaturated carboxylic acid or a derivative thereof. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and the like. As the unsaturated carboxylic acid derivative, acid anhydrides, esters, amides, imides, metal salts and the like can also be used. Specifically, maleic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, malee Acid monoethyl ester, maleic acid diethyl ester, fumaric acid monomethyl ester, fumaric acid dimethyl ester, itaconic acid monomethyl ester, itaconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethyl Amides, maleic acid-N, N-diethylamide, maleic acid-N-monobutylamide, maleic acid-N, N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoe Luamide, fumaric acid-N, N-diethylamide, fumaric acid-N-monobutylamide, fumaric acid-N, N-dibutylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, Examples include potassium acrylate and potassium methacrylate. The graft-modified product is preferably obtained by graft-modifying the graft monomer with respect to the polyolefin resin and the functional group-containing polyolefin resin, generally 0.005 to 10% by weight, preferably 0.01 to 5% by weight.

  As the thermoplastic resin of the base layer (A), 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. Furthermore, among these polyolefin resins and functional group-containing polyolefin resins, propylene resins are preferred from the standpoints of chemical resistance and cost. The propylene-based resin is a propylene homopolymer and is mainly composed of polypropylene, propylene having isotactic or syndiotactic and various degrees of stereoregularity, and ethylene, 1-butene, 1-hexene, It is desirable to use, as a main component, a copolymer obtained by copolymerizing an α-olefin such as 1-heptene or 4-methyl-1-pentene. This copolymer may be a binary system or a ternary system or may be a random copolymer or a block copolymer. The propylene resin is preferably used by blending 2 to 25% by weight of a resin having a melting point lower than that of the propylene homopolymer. Examples of such a resin having a low melting point include high-density or low-density polyethylene.

  In addition to the thermoplastic resin, an inorganic fine powder, an organic filler, a heat stabilizer (antioxidant), a light stabilizer, a dispersant, a lubricant and the like can be added to the base layer (A) as necessary. When adding an inorganic fine powder, an average particle diameter is 0.01-15 micrometers normally, Preferably it is 0.1-5 micrometers. Specifically, calcium carbonate, calcined clay, silica, diatomaceous earth, white clay, talc, titanium oxide, barium sulfate, alumina, zeolite, mica, sericite, bentonite, sepiolite, vermiculite, dolomite, wollastonite, glass fiber, etc. Can be used.

  When an organic filler is added, it is preferable to select a different type of resin from the thermoplastic resin that is the main component. For example, when the thermoplastic resin film is a polyolefin resin film, examples of the organic filler include polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6, cyclic polyolefin, polystyrene, and polymethacrylate. A polymer having a melting point (for example, 170 to 300 ° C.) or a glass transition temperature (for example, 170 to 280 ° C.) higher than the melting point of the polyolefin resin and incompatible can be used.

  When a heat stabilizer is added, it is usually added within a range of 0.001 to 1% by weight. Specifically, sterically hindered phenol-based, phosphorus-based, amine-based stabilizers, and the like can be used. When a light stabilizer is used, it is usually used within a range of 0.001 to 1% by weight. Specifically, sterically hindered amines, benzotriazole-based, benzophenone-based light stabilizers, and the like can be used. A dispersant or a lubricant is used for the purpose of dispersing inorganic fine powder, for example. The amount used is usually in the range of 0.01 to 4% by weight. Specifically, silane coupling agents, higher fatty acids such as oleic acid and stearic acid, metal soaps, polyacrylic acid, polymethacrylic acid or salts thereof can be used.

The thickness of the base layer (A) is usually 30 to 500 μm, preferably 70 to 300 μm. If it is less than 30 μm, sticking is likely to occur when it is pasted on an adherend as wallpaper or the like, and it is difficult to use practically because it cannot be neatly pasted on the adherend. On the other hand, if it exceeds 500 μm, the water-absorbing easily peelable film becomes high, and the processing and printing suitability deteriorates.
The base layer (A) may have a two-layer structure or a multilayer structure of three or more layers. Various functions such as writability, printability, scratch resistance, and secondary processing suitability can be added by multilayering the base layer (A).

When the base layer (A) has a multilayer structure, the content of at least one of the inorganic fine powder and the organic filler in the (A1) layer that is in contact with the water-absorbing easily peelable layer (B) described later is the water-absorbing easily peelable layer (B 5% by weight or more, preferably 10% by weight or less. Voids in the water-absorbing easily peelable layer (B) and the layer (A1) when the content of at least one of the inorganic fine powder and the organic filler in the (A1) layer is 5% by weight or more lower than the water-absorbing easily peelable layer (B). The rate can be different, and it is possible to propagate the fracture only to the easily absorbable release layer (B). Specifically, the (A1) layer comprises 35 to 100% by weight of a thermoplastic resin, preferably 40 to 100% by weight, and 0 to 65% by weight, preferably 0 to 60% by weight, of at least one of inorganic fine powder and organic filler. %including.
The number of stretching axes of this multilayer structure is, for example, in the case of a two-layer structure, as a surface layer / (A1) layer, unstretched / uniaxial, unstretched / 2-axis, 1-axis / 1-axis, 1-axis / 2-axis, 2 axis / 1 axis, 2 axis / 2 axis can be exemplified.

[Easily water-absorbing release layer (B)]
The water-absorbing easily peelable layer (B) in the present invention is capable of absorbing liquid, so that a water-based adhesive can be applied in particular, and can be adhered to an adherend via the adhesive. At the same time, it is a layer that is more brittle and weaker than the base layer (A), and the film can be easily peeled off in a manner that does not contain an adhesive due to the destruction of the layer (B). In addition, since the same layer (B) can be peeled in a uniform surface as compared with a conventionally known water-absorbing layer, coarse irregularities derived from the same layer (B) are not left on the adherend surface. The appearance does not deteriorate the appearance even if another film is applied again.
In the present invention, the absorption of liquid in the easily absorbable release layer (B) is carried out by blending inorganic fine powder whose surface is hydrophilized with a surface treatment agent and stretching the same layer (B) as a core. This is due to the formation of numerous surface openings and internal vacancies.

Moreover, peeling of the film of this invention is performed by destruction (cohesive failure) of a water absorption easily peeling layer (B). In the present invention, in order to facilitate the destruction of the same layer (B), at least two kinds of resins that are incompatible with each other are blended as a resin material and stretched in a phase-separated state so that the pores Peeling occurred not only at the interface but also at the interface between these resins, and the same layer (B) could be peeled in a uniform plane.
The water-absorbable easily peelable layer (B) of the present invention comprises 30 to 60% by weight, preferably 35 to 50% by weight, of a crystalline polypropylene resin and a blend of thermoplastic resin incompatible with the crystalline polypropylene resin. 40 to 70% by weight, preferably 50 to 65% by weight, of the inorganic fine powder whose surface has been hydrophilized, and the easily absorbable release layer (B) is stretched in at least one axial direction. . If the content of the inorganic fine powder in the water-absorbing easily peelable layer (B) is less than 40% by weight, sufficient peelability cannot be obtained. Conversely, if it exceeds 70% by weight, the molding stability is impaired.

  In the blend, the thermoplastic resin incompatible with the crystalline polypropylene resin is 105 to 300 parts by weight, preferably 120 to 285 parts by weight, more preferably 140 to 270 parts by weight with respect to 100 parts by weight of the crystalline polypropylene resin. Is blended in proportions. Thermoplastic resins incompatible with the crystalline polypropylene resin are polyethylene resin, styrene resin, cyclic polyolefin resin, ethylene-cyclic olefin copolymer resin, nylon-6, nylon-6,6, nylon-6,10, Polyamide resins such as nylon-6, 12, polyethylene terephthalate and copolymers thereof, polyethylene naphthalate, polybutylene terephthalate, polybutylene succinate, polylactic acid, thermoplastic polyester resins such as aliphatic polyester, polycarbonate, etc. It is done. These may be used in combination of two or more. Among these, it is preferable to use a polyethylene resin from the viewpoint of chemical resistance and production cost. Due to the presence of the incompatible thermoplastic resin, interfacial peeling occurs between the crystalline polypropylene resin and the polypropylene resin incompatible with the crystalline polypropylene resin and the polypropylene resin when the stretched film is produced, thereby improving the peelability. If the thermoplastic resin incompatible with the polypropylene resin is less than 105 parts by weight or more than 300 parts by weight, sufficient peelability cannot be obtained.

（上記式（１）中、ρＳは結晶性ポリプロピレン樹脂の密度であり、ρＣは論理的に求められたポリプロピレン樹脂の結晶部の密度（０．９３８ｇ／ｃｍ³）であり、ρＡは論理的に求められたポリプロピレン樹脂の非晶部の密度（０．８５２ｇ／ｃｍ³）である。）
そのため上記の結晶化度を達成するためには、吸水易剥離層（Ｂ）に用いる結晶性ポリプロピレン樹脂の密度が０．９０６ｇ／ｃｍ³以上であることが好ましく、０．９０７ｇ／ｃｍ³以上であることがより好ましく、０．９０８ｇ／ｃｍ³以上であることが特に好ましい。
本発明において「非相溶」とは、結晶性ポリプロピレン樹脂と、非相溶性の熱可塑性樹脂のブレンド物を電子顕微鏡で観察した場合、海島構造のモルフォロジーを有しており、その構造の寸法が０．３〜１０μｍであることを指す。 In the present invention, the crystalline polypropylene resin is the above-mentioned propylene-based resin, and its crystallinity is preferably 65% or more, more preferably 66% or more, and 67 to 80%. Particularly preferred. If the degree of crystallinity is 65% or more, the compatibility between the amorphous part of the crystalline polypropylene resin and the thermoplastic resin is difficult to proceed, and the desired interfacial peeling effect can be easily obtained, and the stress required for peeling (peeling strength) ) Can be made reasonably small. Moreover, if the degree of crystallinity is 80% or less, it is easy to obtain commercially.
In the present invention, the crystallinity of the crystalline polypropylene resin is determined by subjecting the resin sample to an annealing treatment for 90 minutes in an oven set at 105 ° C., and then at a temperature of 23 ° C., a density gradient tube method or an underwater substitution method. It was calculated using the following formula (1) from the density of the crystalline polypropylene resin obtained by (both can be mutually corrected by a conversion formula).

(In the above formula (1), ρS is the density of the crystalline polypropylene resin, ρC is the theoretically determined density (0.938 g / cm ³ ) of the crystal part of the polypropylene resin, and ρA is logically (The density of the amorphous part of the obtained polypropylene resin (0.852 g / cm ³ ).)
Therefore in order to achieve the above crystallinity is preferably the density of the crystalline polypropylene resin used in the water easily-peelable layer (B) is 0.906 g / cm ³ or more, at 0.907 g / cm ³ or more More preferably, it is 0.908 g / cm ³ or more.
In the present invention, “incompatible” means that when a blend of a crystalline polypropylene resin and an incompatible thermoplastic resin is observed with an electron microscope, it has a morphology of a sea-island structure, and the size of the structure is It means 0.3 to 10 μm.

  In the inorganic fine powder whose surface is hydrophilized by the surface treatment agent, the inorganic fine powder includes heavy calcium carbonate, light calcium carbonate, calcined clay, talc, titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, Examples thereof include inorganic fine powder such as silicon oxide, composite inorganic fine powder having aluminum oxide or hydroxide around the core of inorganic fine powder, 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. Examples of the surface treatment agent include water-soluble anionic surfactants, water-soluble cationic surfactants, and water-soluble nonionic surfactants having an average molecular weight of 1,000 to 15,000.

  Specific examples of such surfactants include, for example, water-soluble anionic surfactants, sulfonates having a hydrocarbon group having 4 to 40 carbon atoms, and hydrocarbon groups having 4 to 40 carbon atoms. Examples thereof include phosphoric acid ester salts, salts of mono- or diesters of higher alcohols having 4 to 40 carbon atoms, and alkylbetaines and alkylsulfobetaines having hydrocarbon groups having 4 to 40 carbon atoms. For example, water-soluble cationic surfactants include diallylamine salts, alkyl diallylamine salts and dialkyl diallylamine salts having 1 to 4 carbon atoms, that is, methyl diallylamine salt, ethyl diallylamine salt, dimethyl diallylamine salt, methacryloyloxyethyltrimethylammonium, acryloyl. Epidemic oxyethyltrimerylammonium, methacryloyloxyethyldimethylethylammonium or acryloyloxyethyldimethylethylammonium chloride, bromide, methosulphate or ethosulphate, N, N-dimethylaminoethyl methacrylate or N, N-dimethylaminoethyl acrylate Epoxidation of chlorohydrin, glycidol, glycidyl trimethyl ammonium chloride, etc. Quaternary ammonium salts obtained by alkylation and the like in the object. Among these, preferred are diallylamine salt, methyldiallylamine salt and dimethyldiallylamine salt. For example, water-soluble nonionic surfactants include acrylamide, methacrylamide, N-vinylformamide, N-vinylacetamide, N-vinylpyrodoline, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxy (meta ) Acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, and (meth) acrylic acid butyl ester. Among these, acrylamide and methacrylamide are preferable.

Moreover, in addition to the inorganic fine powder which hydrophilized the said surface, the water absorption easily peeling layer (B) of this invention may mix | blend combining a different kind of inorganic fine powder and organic fine powder. good. Specifically, the water-absorbing easily peelable layer (B) may further contain 0.1 to 30% by weight of at least one of an inorganic fine powder and an organic fine powder whose surface is not hydrophilized. When blended in combination, when the fine powder used in the water-absorbing easily peelable layer (B) is 100% by weight, the inorganic fine powder whose surface is hydrophilized is 50 to 99.9% by weight, and the surface is hydrophilic. It is preferable that at least one of the inorganic fine powder and the organic fine powder not subjected to the hydrotreating is 0.1 to 50% by weight, the surface of the inorganic fine powder whose surface is hydrophilized is 55 to 80% by weight, and the surface is hydrophilic. It is more preferable that at least one of the inorganic fine powder and the organic fine powder not subjected to the chemical treatment is 20 to 45% by weight.
Here, the “inorganic fine powder whose surface is not hydrophilized” refers to an inorganic fine powder that is not intentionally hydrophilized by the above-mentioned surface treatment agent, and includes processes such as normal pulverization, classification, and sedimentation. It refers to the inorganic fine powder obtained through the process. For example, the amount of eluate from the water-absorbing easily peelable layer (B) can be adjusted by mixing a hydrophilic calcium carbonate fine powder and a normal heavy calcium carbonate fine powder. Water absorption can be adjusted by combining calcium fine powder and organic fine powder. Even when blending different types of fine powder in this way, if the total amount of fine powder exceeds 70% by weight, the stretchability of the water-absorbable easily peelable film deteriorates and the molding stability is impaired, which is not preferable. .

Moreover, in order to disperse | distribute inorganic fine powder uniformly finely, it is preferable that the water-absorbing easily peeling layer (B) of this invention contains a dispersing agent.
Examples of the inorganic fine powder dispersant include acid-modified polyolefin and silanol-modified polyolefin.
In the present invention, it is particularly preferable to use maleic acid-modified polyolefin and silanol-modified polypropylene.
The acid-modified polyolefin includes a hydroxyl-free polyolefin obtained by random copolymerization or graft copolymerization of maleic anhydride, or a carboxylic acid group-containing polyolefin obtained by random copolymerization or graft copolymerization of an unsaturated carboxylic acid such as methacrylic acid or acrylic acid. And epoxy group-containing polyolefin obtained by random copolymerization or graft copolymerization of glycidyl methacrylate. Specific examples include maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene, acrylic acid-modified polypropylene, ethylene / methacrylic acid random copolymer, ethylene / glycidyl methacrylate random copolymer, ethylene / glycidyl methacrylate graft copolymer, glycidyl. Examples thereof include methacrylate-modified polypropylene. Among them, maleic anhydride-modified polypropylene and maleic anhydride-modified polyethylene are particularly preferable.

Specific examples of maleic anhydride-modified polypropylene and maleic anhydride-modified polyethylene include Modic AP manufactured by Mitsubishi Chemical Corporation, trade name “P513V”, trade name “M513”, trade name “P928”, Sanyo Chemical Industries, Ltd. Product name “Umex1001”, product name “Umex1010”, product name “Umex2000”, HPR manufactured by Mitsui DuPont Chemical Co., Ltd., and product name “VR101”.
The acid modification rate of the acid-modified polyolefin is preferably 0.01 to 20%, more preferably 0.05 to 15%. If the acid modification rate is 0.01% or more, the effect of dispersing the surface-treated inorganic fine powder in the resin blend can be sufficiently obtained. When the acid modification rate is 20% or less, since the softening point of the acid-modified polyolefin does not become too low, compounding with a thermoplastic resin is relatively easy.

  The content of the dispersing agent when blending the dispersing agent into the water-absorbing easily peelable layer (B) is usually 0.5 to 30 parts by weight, preferably 1 to 20 parts by weight with respect to 100 parts by weight of the surface-treated inorganic fine powder. Part. When the content of the dispersant is 0.5 parts by weight or more, the surface-treated inorganic fine powder is sufficiently dispersed, so that a desired surface opening ratio is easily obtained and the liquid absorption volume is easily improved. Moreover, if it is 30 parts weight or less, a drawability is favorable and it can suppress the draw break at the time of shaping | molding.

  The wall thickness of the easily absorbable release layer (B) is preferably in the range of 1 to 30 μm, more preferably 1.5 to 15 μm. If it is 1 μm or more, sufficient peelability and liquid absorption volume tend to be obtained. In addition, there is no problem with the peeling strength when peeling even if it exceeds 30 μm, but if it is 30 μm or less, the peeling position is stable and the peeling surface is likely to be uniform. There is a tendency that it is difficult to be raised on the surface. The water-absorbing easily peelable layer (B) is a stretched resin film layer that is stretched in at least one axial direction. Forming surface openings and internal vacancies by stretch molding to obtain a layer (B) that is easily peeled uniformly by orientation of the resin, and at the same time obtaining a water-absorbing easily peelable layer (B) that is thin and uniform. Is possible.

  Moreover, it is preferable that the surface opening rate of a water absorption easily peeling layer is 7% or more, and it is more preferable that they are 10%-40%. If the surface opening ratio is 7% or more, sufficient liquid absorbability tends to be obtained.

  The “surface aperture ratio” in the present specification indicates an area ratio occupied by pores in the observation region when the surface on the water-absorbing easily peelable layer (B) side is observed with an electron microscope. Specifically, an arbitrary part is cut out from the laminated resin film sample, pasted on the observation sample stage, gold or gold-palladium or the like is vapor-deposited on the observation surface, and scanning by an electron microscope (for example, manufactured by Hitachi, Ltd.) It can be determined by observing surface vacancies at an arbitrary magnification (for example, magnification of 500 to 3000 times) that is easy to observe using a scanning microscope S-2400). Further, the observed area was photographed, and the holes were traced on the tracing film, and the image filled with the image was processed with an image analysis device (manufactured by Nireco Corporation: model Luzex IID). It can be set as the aperture ratio of the surface of a water absorption easily peeling layer (B).

[Production of film]
It is preferable that the base layer (A) and the easily absorbable release layer (B) are stretched in at least a uniaxial direction after lamination. Since the water-absorbing easily peelable layer (B) of the present invention is low in strength and thin, it is extremely difficult to stretch-mold the water-absorbing easily peelable layer (B) as a single layer. By stretching after laminating the base layer (A) and the water-absorbable easily peelable layer (B), the water-absorbable easily peelable layer (B) can be easily stretched. Therefore, the base layer (A) is also useful as a support for stretching the water-absorbing easily peelable layer (B).
Various known methods can be used for such a laminating method. Specific examples include a multi-layer die method using a feed block and a multi-manifold, and an extrusion lamination method using a plurality of dies. It is also possible to use a combination of multilayer dies and extrusion lamination.

  Various known methods can be used for stretching. The stretching temperature can be carried out within a known temperature range suitable for a thermoplastic resin having a temperature not lower than the glass transition temperature of the thermoplastic resin mainly used for the base layer (A) and not higher than the melting point of the crystal part. Specifically, when the thermoplastic resin of the base layer (A) is a propylene homopolymer (melting point 155 to 167 ° C.), it is 100 to 166 ° C., and when it is a high density polyethylene (melting point 121 to 136 ° C.), it is 70 to 135 ° C. The temperature is 1 to 70 ° C. lower than the melting point. Specific methods of stretching include stretching between rolls utilizing the peripheral speed difference of the roll group, clip stretching using a tenter oven, and the like. According to the inter-roll stretching, there is a risk that the surface treatment agent contained in the water-absorbing easily peelable layer (B), which is the outermost layer, adheres and accumulates on the roll.

  The draw ratio is not particularly limited, and is determined in consideration of the purpose of use of the wallpaper and label of the present invention and the characteristics of the resin used. When the number of stretching axes is uniaxial, the stretching ratio is usually 2 to 11 times, preferably 3 to 10 times. Among these, the draw ratio is more preferably 4 to 7 times. In the case of clip stretching using a tenter oven, stretching is preferably performed 4 to 11 times. When the number of drawing axes is biaxial, the area magnification is usually 2 to 80 times, preferably 3 to 60 times, more preferably 4 to 50 times. If the area magnification is less than 2 times, a predetermined opening ratio cannot be obtained on the surface of the film, and sufficient water absorption cannot be obtained, and it becomes difficult to provide an adhesive layer with good adhesion to the adherend on the surface. Tend. Moreover, when it exceeds 80 times, there exists a tendency for extending | stretching cut | disconnection and coarse perforation to increase.

  It is preferable to heat-treat the laminated resin film after stretching. 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 in the stretching direction is reduced, and squeezing due to shrinkage at the time of product storage and heat and fusing sealing is reduced. The heat treatment is generally performed in a roll or a heat oven, but these 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.

  Further, after the heat treatment, the surface is preferably subjected to oxidation treatment such as corona discharge treatment or plasma treatment. The wettability of the surface is further improved by performing the oxidation treatment, and when the aqueous adhesive layer is provided, the solvent absorption rate of the aqueous adhesive is improved, and the adhesive component is present in the opening on the surface of the water-absorbable easily peelable layer (B). This is desirable because it has the advantage of getting faster and more. Furthermore, there also exists an advantage which the adhesiveness of a water absorption easily peeling layer (B) and a water-system adhesive improves.

The liquid absorption volume of the water-absorbing easily peelable layer (B) produced by the above method is preferably 1 to ²⁰ ml / m ² . This can be adjusted by the internal porosity of the water-absorbable easily peelable layer (B) affected by the blending amount of the surface-treated inorganic fine powder and the draw ratio, and the thickness of the water-absorbable easily peelable layer (B). When the liquid absorption volume is less than 1 ml / m ² , the adhesive does not dry when the laminated resin film is attached to the adherend via the adhesive, and the desired performance of the present invention is not exhibited. In the present specification, “liquid absorption volume” refers to JAPAN TAPPI No. Measured by a Bristow liquid absorbency test in accordance with 51: 2000, using a Bristow tester type II manufactured by Kumagai Riki Kogyo Co., Ltd. in a non-pressurized state with red water. 20 μl of a 20: 1 mixture of ink was added dropwise to determine the liquid transfer amount at 50 ms.

The peel strength of the water-absorbable easily peelable layer (B) is preferably in the range of 50 to 180 gf / 18 mm, and the peel preferably proceeds in a uniform plane due to cohesive failure in the water-absorbable easily peelable layer (B). The peel strength indicates the strength required to peel off the film after being attached to the adherend, but the peeling itself proceeds by destruction of the water-absorbable easily peelable layer (B) where there is no penetration of the adhesive, In the present invention, a pressure-sensitive adhesive tape is artificially attached to the water-absorbing easily peelable layer (B), and the strength required for peeling the adhesive tape is measured and replaced with this.
When the peel strength is less than 50 gf / 18 mm, it is easy to peel off when applied to the adherend, and when the peel strength exceeds 180 gf / 18 mm, depending on the type of adhesive, The strength exceeds the strength, or the surface strength of the adherend exceeds when adhered to the adherend, and cohesive failure does not occur in the water-absorbable easily peelable layer (B). In the present specification, “peel strength” means that an adhesive tape (cellophane tape manufactured by Nichiban Co., Ltd., product name “cello tape”, brand name “CT-18”) is attached to the surface of the easily absorbable release layer (B), Cut to a length of 100 mm, using a tensile testing machine (trade name “AUTOGRAPH” manufactured by Shimadzu Corporation), and at a pulling speed of 300 mm / min, the angle between the base layer (A) and the adhesive tape is 180 °. Peeling was generated in the easily absorbable peelable layer (B), and the stress when the peeling was stable was measured with a load cell, and obtained from the average value in the horizontal and vertical directions.

[Concealment layer (C)]
When the water-absorbable easily peelable film of the present invention is used as wallpaper or the like, the film is preferably opaque so that the base is not seen through. In order to make the water-absorbable easily peelable film opaque, the water-absorbable easily peelable film preferably has a concealing layer (C).
Specific examples of the concealing layer (C) of the present invention include colored printing such as black printing or gray printing on the surface of the easily absorbable release layer (B). These can be easily applied to a water-absorbing easily peelable film, but it is preferable to carry out the coating so as not to hinder the application of the adhesive described later.

  Another specific example of the masking layer (C) is one that improves the opacity of the base layer (A). For example, a method of increasing the opacity by adding a pigment having strong concealment to the raw material composition of the base layer (A), for example, titanium oxide powder, aluminum powder, carbon black, etc., or forming the base layer (A) as a multilayer structure between the layers A method of inserting black printing is mentioned. The method of inserting black printing between the layers is to perform black printing on one or both surfaces of the layers constituting the layer in advance, and stack them so that the black printing is sandwiched by a method such as dry lamination using an adhesive. Good.

[Application of easily absorbable water-releasing film]
The water-removable easily peelable film of the present invention can be added with various functions such as writing property, printability, scratch resistance, and secondary processing suitability by making the base layer (A) multilayer. In particular, since the product of the present invention is used as a wallpaper or container label, printability is particularly required. For imparting printability to the film, a conventionally known method such as lamination of a coat layer can be used. As printing, gravure printing, offset printing, flexographic printing, screen printing, ink jet printing, electrophotographic printing, etc., the pattern on the label, barcode, manufacturer, sales company name, character, product name, usage, etc. Designs and information can be given.

When the water-absorbable easily peelable film of the present invention is used as wallpaper, it is preferable to use the film in the form of a long roll (roll), and the printing mode includes gravure printing, flexographic printing, inkjet printing using a plotter, etc. Is preferred.
When the water-absorbable easily peelable film of the present invention is used as a label, it is preferable that higher-definition printing can be performed, and the printing mode is preferably offset printing.
When printing on a water-absorbing easily peelable film of the present invention by a technique such as ink jet printing, a coating layer (in accordance with the printing technique) is used in order to immobilize the color material on the surface on the base layer (A) side serving as the printing surface. D) is preferably provided.

[Coat layer (D)]
The coating layer (D) suitable for the water-releasable easily peelable film of the present invention is particularly applicable to ink jet printing including aqueous ink jet, solvent ink jet, UV ink jet, latex ink jet and the like. Is preferably a coating layer (D) containing polyvinyl alcohol to which silica is added, or a polyether urethane to which silica is added for UV inkjet.

  The water-absorbing easily peelable film of the present invention is obtained by directly applying an adhesive to the back surface (water-absorbing easily peelable layer (B) side), wood wall material, gypsum board, various composite materials (resin decorative board, wood plywood, etc.) ), Iron plate, aluminum plate, glass, earthenware, and an adherend made of resin, and can be directly bonded together. For this reason, when using the easily absorbable peelable film of this invention for a wallpaper, a label, etc., it is not necessary to lining the back material (natural paper etc.) on the back surface. For this reason, when the water-absorbing easily peelable film of the present invention constructed as wallpaper and labels is peeled off from the adherend and recycled, the backing material (natural paper, etc.) is not mixed into the recycled raw material, and has a uniform surface shape. Since all the adhesive remains on the adherend side by peeling and does not remain on the film side, the material can be recycled.

  The adhesive used for laminating the water-removable easily peelable film of the present invention is not particularly limited, and protein-based adhesives, water-containing carbon-based adhesives, synthetic resin-based adhesives, solvent-based adhesives, and the like can be used. it can. Here, adhesives that use water as a medium, such as protein adhesives, water-containing carbon adhesives, and synthetic resin adhesives, are collectively referred to as aqueous adhesives. The adhesive may be either water-based or solvent-based, but it is preferable to use a water-based adhesive from the viewpoint of workability and safety (poisoning due to solvent scattering, fire, etc.).

  A water-based adhesive has a property of dissolving or swelling in water. Examples of protein-based adhesives include gelatin, glue, and casein. Examples of the water-containing carbon adhesive include starch and derivatives thereof, and examples of the cellulose derivative include hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose (CMC), and viscose. Other examples include arabic rubber and tragacanth rubber.

  Examples of the synthetic resin adhesive include polyvinyl alcohol, polyvinyl ether, and polyvinyl pyrrolidone. In addition, polyacrylamide, polyethylene oxide, polyvinyl amide, water-soluble polyurethane, polyacrylic acid resin and salts thereof, and the like can be given. Furthermore, the adhesive agent using the emulsion obtained by emulsion polymerization etc., such as vinyl acetate, acrylic acid ester, ethylene vinyl acetate, vinyl chloride, is also mentioned.

  Among them, as an aqueous adhesive used for bonding the water-absorbable easily peelable film of the present invention to an adherend, starch and its derivatives, polyacrylic acid, polyacrylamide, polyethylene oxide, polyvinyl alcohol, from the viewpoint of workability and adhesiveness. , Carboxymethylcellulose (CMC), vinyl acetate, and polyvinylamide are preferable, and starch and derivatives thereof are more preferably used.

After the water-absorbable easily peelable film of the present invention is peeled off from the wall surface or bottle, the water-absorbable easily peelable layer (B) having water absorption performance remains on the wall surface or bottle. If you apply water-based adhesive directly to the water-absorbable easily peelable layer (B) of another water-absorbable easily peelable film and apply it from above the water-absorbable easily peelable layer (B) remaining on the wall or bottle Sufficient adhesion can be obtained. In other words, when applying a new wallpaper or label to the adherend, it is necessary to work after peeling off the water-absorbable release layer (B) remaining on the wall or bottle after peeling off the previous wallpaper or label. However, it is possible to repeatedly apply the water-absorbing easily peelable layer (B) remaining on the wall surface or the bottle.
The adhesive and the water-absorbable easily peelable layer (B) remain and accumulate on the wall surface or bottle as the adherend each time due to the adhesion / peeling cycle of the water-absorbable easily peelable film of the present invention. Since B) peels into a thin and uniform surface, non-uniform unevenness does not occur and appearance deterioration hardly occurs.

  Hereinafter, the present invention will be described more specifically with reference to examples and test examples. The material, amount used, ratio, processing content, processing procedure, and the like employed in the embodiments can be changed as appropriate without departing from the spirit of the present invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Examples 1-19, Comparative Examples 1-7]
Laminated resin films (Examples 1 to 19 and Comparative Examples 1 to 7) were produced according to the following procedure. Table 1 shows details of the materials used. “MFR” in the table means melt flow rate. Tables 2 and 3 list the type and amount (% by weight) of materials used in the production of each laminated resin film, stretching conditions, total thickness and thickness of the [B] layer, and the presence or absence of the [C] layer. The material numbers listed in Tables 2 and 3 correspond to the material numbers listed in Table 1.

In Examples 1 to 18 and Comparative Examples 1 to 5, the compound [A1] described in Table 2 or Table 3 was melt-kneaded with an extruder set at 250 ° C. and extruded into a sheet through a die. And it cooled to 70 degreeC with the cooling device, and obtained the unstretched sheet | seat of the single layer. The unstretched sheet was heated to 145 ° C. and then stretched 5 times between rolls in the longitudinal direction to obtain a longitudinally uniaxially stretched film. Next, the compound [A2] described in Table 2 or Table 3 was melt-kneaded with an extruder set at 250 ° C. and extruded into a sheet shape through a die, and laminated on one surface of the longitudinally uniaxially stretched film, Further, the blend [B] shown in Table 2 or Table 3 was melt-kneaded with another extruder set at 250 ° C. and extruded into a sheet shape through a die, and was applied to the other surface of the longitudinally uniaxially stretched film. Laminated. The laminate was heated to 158 ° C. and stretched 9 times in the transverse direction using a tenter stretching machine to obtain a laminated resin film having a three-layer structure that was uniaxially stretched / biaxially stretched / uniaxially stretched (see FIG. 2). ).
In particular, in Example 9, gravure ink (trade name: XS-756, manufactured by DIC Graphics Co., Ltd.) and a gravure printing machine were used on the surface of the laminated resin film obtained in Example 2 on the [B] layer side. Gray printing was performed to obtain a laminated resin film provided with a concealing layer (C).

In Example 19, the blend [A2], the blend [A1] and the blend [B] shown in Table 3 were melt-kneaded with three extruders set at 250 ° C., respectively, to feed block, multi-manifold Was laminated in a die through a multi-layer die using the same, and this was coextruded into a sheet shape and cooled to 70 ° C. with a cooling device to obtain a three-layer unstretched sheet. This unstretched sheet was heated to 145 ° C., then stretched 5 times between rolls in the machine direction, then heated to 158 ° C. and stretched 9 times in the transverse direction using a tenter stretching machine, biaxially stretched / 2 A laminated resin film having a three-layer structure obtained by axial stretching / biaxial stretching was obtained (see FIG. 2).
In Comparative Example 6, the compound [A1] and the compound [B] shown in Table 3 were melt-kneaded with two extruders set at 250 ° C., respectively, to produce a multilayer die using a feed block and a multi-manifold. Then, it was laminated in a die, and this was coextruded into a sheet and cooled to 70 ° C. with a cooling device to obtain a two-layer unstretched sheet. The unstretched sheet was heated to 145 ° C. and then stretched 5 times between rolls in the longitudinal direction to obtain a longitudinally uniaxially stretched film. Next, the blend [A2] shown in Table 3 was melt-kneaded with an extruder set at 250 ° C., extruded into a sheet through a die, and laminated on the [A1] side of the longitudinally uniaxially stretched film. The laminate was heated to 158 ° C. and stretched 9 times in the transverse direction using a tenter stretching machine to obtain a laminated resin film having a three-layer structure that was uniaxially stretched / biaxially stretched / biaxially stretched (see FIG. 2). ).
When obtaining the laminated resin film of Example 2, the laminate obtained by laminating the compound [A2] and the compound [B] on both sides of the longitudinally uniaxially stretched film while changing the resin discharge amount of the extruder, The laminated resin film of Comparative Example 7 was obtained.

[Example 20]
The surface of the laminated resin film obtained in Example 2 on the [A2] side is coated with a coating liquid having the following composition using a gravure coater so that the solid content is about 2.0 g / m ^2. And dried to form a coat layer (D) suitable for aqueous inkjet printing.
<Coating solution composition>
Synthetic silica powder 100 parts by weight (trade name “Mizukasil P-78D”, average particle size 8 μm, manufactured by Mizusawa Chemical Co., Ltd.)
30 parts by weight of polyvinyl alcohol (trade name “Kuraray Poval PVA-117”, manufactured by Kuraray Co., Ltd.)
10 parts by weight of an epichlorohydrin adduct of polyamide polyamine (trade name “WS4082”, manufactured by Seiko PMC Co., Ltd.)
Polyacrylic acid soda 5 parts by weight (reagent, manufactured by Wako Pure Chemical Industries, Ltd.)
1600 parts by weight of water

[Example 21]
A metal foil was transferred and deposited on the surface of the laminated resin film obtained in Example 2 on the [A2] layer side, and a coating liquid containing a polyamidopolyamine resin (trade name “Topaz” was used on the surface of the metal foil using a gravure coater. 17 liquid ", manufactured by Toyo Ink Mfg. Co., Ltd., so that the solid content is about 0.5 g / m ^2, and dried to be a wet electrophotographic printing machine (for example, trade name“ Indigo WS4000 ”, A coat layer (D) suitable for printing by Hewlett-Packard Co. was formed.

  In any of the manufactured laminated resin films, the ratio of the thicknesses of the [A1] layer and the [A2] layer was 1:24.

[Test example]
For each laminated resin film produced in Examples and Comparative Examples, printing characteristics, opacity, liquid absorption volume, peel strength, peelability to gypsum board, adhesiveness / peelability to bottles, concealability, re-sticking workability, recycling Suitability was evaluated. Details of each test are as follows.

[Printability]
[A2] Adhesive tape (made by Nichiban Co., Ltd., trade name “Cerotape”, brand name “CT-18”) is pasted on the ink surface of each laminated resin film gravure-printed on the side surface, and pressed sufficiently with fingers After that, the adhesive tape is manually peeled off at a speed of about 1000 mm / sec by pulling the non-adhered part while keeping the angle between the non-adhered part of the adhesive tape and the laminated resin film at 90 degrees, and the ink is removed. The manner of evaluation was evaluated according to the following criteria, and evaluated according to the following four levels.
◎: Ink does not peel off at all ○: Some of the ink is peeled off as the material part of the film breaks, but there is no practical problem △: Although there is resistance when peeling, most of the ink is peeled off, causing practical problems Yes X: The whole amount of ink is peeled off, there is no resistance when peeling, and it cannot be used practically

[Opacity]
Based on JIS-P-8149, the ratio of the reflectance of light measured by applying a black and white standard plate to the back of each laminated resin film ([B] side) (single sheet luminous reflectance / intrinsic luminous reflection) Rate) as a percentage.

[Liquid absorption volume]
JAPAN TAPPI No. It measured by the Bristow liquid absorptivity test based on 51: 2000. Specifically, 20 μl of a mixture of 20: 1 red water-based ink was added to ion-exchanged water in a non-pressurized state using a Bristow tester type II manufactured by Kumagai Riki Kogyo Co., Ltd. The amount of liquid transfer at 50 ms was determined.

[Peel strength]
After each laminated resin film is stored in a temperature-controlled room (temperature 20 ° C., relative humidity 65%) for 12 hours, an adhesive tape (made by Nichiban Co., Ltd., trade name “Cello Tape”, Name “CT-18”) was cut out to a length of 100 mm, and a tensile tester (trade name “AUTOGRAPH”) manufactured by Shimadzu Corporation was used at a tensile speed of 300 mm / min. The base layer (A) and the adhesive tape were peeled off at an angle of 180 °, and the stress when stable was measured with a load cell. This measurement was performed in the horizontal direction and the vertical direction of each laminated resin film, and the average value of these values was taken as the peel strength. An adhesive tape having a width of 18 mm was used.

[Peelability on gypsum board]
Each laminated resin film is cut into a 10 cm × 10 cm square, and a water-based adhesive mainly composed of starch on the water-absorbing easily peelable layer (B) side (manufactured by Yayoi Chemical Industry Co., Ltd., trade name “Loua Mild” and Yayoi Chemical Industries). Co., Ltd., trade name “Prazole 100S” and water mixed at 5: 1: 4 respectively) with an automatic wallpaper pasting machine (manufactured by Kyokuto Sangyo Co., Ltd.), the solid content becomes 8 g / m ² Then, it was applied onto a plaster board (manufactured by Yoshino Gypsum Co., Ltd., trade name “Tiger Board”). After storing this at room temperature for one week, the following (1) peeling initiation property and (2) peeling propagation property were evaluated.

(1) Peeling startability After peeling off one side of the four sides of each laminated resin film with a nail from the gypsum board by 1 cm from the end, hold the peeled side by hand, peel it off the gypsum board, and easily absorb water The state until peeling due to cohesive failure of the release layer (B) was observed from the distance, and evaluated in the following four stages. In addition, when peeling off from a gypsum board by hand, it peeled off by pulling the peeling part of a laminated resin film, maintaining the angle which the gypsum board surface and the peeling part of a base layer (A) make about 135 degrees.
A: Release of the water-absorbing easily peelable layer (B) starts immediately (less than 1 mm). O: 1-2 mm is required until the water-absorbing easily peelable layer (B) starts to peel. Δ: Water-absorbing easily peelable layer (B) 3 to 9 mm is required until the peeling of the film starts. ×: It takes 10 mm or more to start the peeling of the water-absorbable easy peeling layer (B).

(2) Peel-propagating property Adhesive tape (made by Nichiban Co., Ltd., trade name “Cerotape”, brand name “CT-18”) is applied to one side of the four sides of each laminated resin film along the side over the entire length of the side. Put the base layer (A) on the gypsum board by pulling the peeled part of the base layer (A) while keeping the angle between the plaster board surface and the peeled part of the base layer (A) at about 135 °. I peeled off more. The peeling propagation state and peeling force of the water-absorbing easily peelable layer (B) at this time were evaluated in the following four stages.
◎: Peeling force is light and peeling is propagated cleanly. ○: Peeling force is slightly heavy, but peeling is propagated cleanly. △: Peeling force is very heavy, but peeling is propagated cleanly. ×: Peeling Cannot be propagated to the entire surface and cut off

[Adhesion and peelability to bottles]
Each laminated resin film is cut into a 5cm x 5cm square, and a commercially available water-based adhesive (trade name "Fujiat AL-8L", manufactured by T & K TOKA Co., Ltd.) is automatically glued on the water-absorbing easy release layer (B) side. The coating was applied so that the solid content was 8 g / m ² (manufactured by TY Seiki) and adhered to a glass bottle. After storage at room temperature for one week, (1) adhesiveness to the bottle, (2) peel initiation, and (3) peel propagation were evaluated.

(1) Adhesiveness to bottles After peeling off one of the four sides of each laminated resin film with a nail from the bottle by 1 cm, hold the peeled side by hand and peel it off the bottle to facilitate water absorption. The state until peeling of the release layer (B) started was observed and evaluated in the following three stages. In addition, when peeling off by hand from a bottle, it peeled off by pulling the peeling part of a laminated resin film, maintaining the angle which the bottle surface and the peeling part of a laminated resin film make at about 135 degrees.
○: The substrate peels easily or breaks when peeling. Δ: Only the label edge peels easily or breaks. ×: Adhesive does not dry and does not adhere to the bottle. ) About the peel propagation property, it evaluated by the method and judgment criteria similar to the test ((1) peeling startability and (2) peel propagation property) with respect to the above-mentioned gypsum board.

[Concealment]
26 letters of alphabet of 10-point character size are printed on government-made postcards, and water-based adhesive (manufactured by Yayoi Chemical Industry Co., Ltd. “Ruair Mild” and Yayoi Chemical Industry Co., Ltd., trade name “Prazole 100S” mixed with water 5: 1: 4) were applied so that the solid content was 8 g / m ² . Pasted on top. The concealability of the characters seen through each laminated resin film was judged visually and evaluated in the following four stages.
◎: The character is completely unknown and good ○: The character cannot be read at all slightly good △: A part of the character is slightly read ×: The whole character is unreadable

[Re-sticking workability]
A water-based adhesive (manufactured by Yayoi Chemical Industry Co., Ltd., trade name "Ruair Mild" and Yayoi) on each laminated resin film on the water-absorbing easily peelable layer (B) side (if the backing paper is used, the backing paper surface). Chemical Co., Ltd., trade name “Prazole 100S” and water mixed at 5: 1: 4) with an automatic wallpaper pasting machine (manufactured by Kyokuto Sangyo Co., Ltd.) with a solid content of 8 g / m ² It was applied so as to be attached to a gypsum board (trade name “Tiger Board” manufactured by Yoshino Gypsum Co., Ltd.). After storing at room temperature for 1 week, each laminated resin film was peeled off from the gypsum board in the same manner as the peel initiation test for the gypsum board. Next, the same water-based adhesive was applied to the peeled surface of each laminated resin film with an automatic wallpaper pasting machine (manufactured by Kyokuto Sangyo Co., Ltd.) so that the solid content was 8 g / m ^2. It was made to re-adhere on the plaster board which has not been affixed, and the external appearance was evaluated. Also, after storing this at room temperature for 1 week, peel one side out of the 4 sides of each laminated resin film with a nail again, and peel it off from the plaster board by 1 cm from the end, and then hold the peeled side by hand. It peeled off more and observed the state of the peeling surface of a water absorption easily peeling layer (B), and evaluated in the following three steps. In addition, when peeling off from a gypsum board by hand, it peeled off by pulling the peeling part of a laminated resin film, maintaining the angle which the gypsum board surface and the peeling part of a laminated resin film make about 135 degrees.
○: The laminated resin film after re-adhesion shows no irregularities in appearance, and when it is peeled off, it peels off again from the water-absorbing layer (B) of the film. △: The laminated resin film after re-adhesion In addition, the uneven appearance of the unevenness is seen on the surface, and the peeling of the easily absorbable release layer (B) from the rebonding surface is non-uniform and has practical problems. X: The appearance of unevenness in the laminated resin film after reattachment And peeling from the rebonding surface is very uneven because it occurs from both the film side and the adherend side,
Cannot be used practically

[Recyclability]
Each wallpaper constructed in the above [Wallpaper Adhesiveness] evaluation was peeled off from the wall surface after one month in the same manner as the peel initiation test on the gypsum board, and the peeled wallpaper was put into a chip by using a grinder. This was set at 225 ° C. and remelted and kneaded and extruded in a twin screw extruder equipped with a 100 mesh screen pack. Whether or not remelt extrusion (resin regeneration) is possible was determined from the screen pack clogging, smoke generation, and discoloration. The state in which the screen pack was not clogged, smoked, or discolored and remelting extrusion (resin regeneration) was possible was judged as “good”.

  The test results of the above evaluation items are summarized in Table 4.

  The easily peelable multilayer resin stretched film described in the examples of JP-A-2002-200707 is reproduced and the same test as described above is performed. The re-pasting workability and recyclability of Examples 1 to 19 of the present invention are clearly superior to the examples of JP-A-2002-200707, and the other evaluation results are equivalent.

A Base layer B Water-absorbing easy release layer

Claims (18)

A water-absorbing easily peelable film comprising a laminated resin film of a base layer (A) and a water-absorbing easily peelable layer (B),
The base layer (A) contains a thermoplastic resin,
The water-absorbable easily peelable layer (B) is an inorganic material whose surface is hydrophilized with a surface treatment agent and a blend of 30 to 60% by weight of a crystalline polypropylene resin and a thermoplastic resin incompatible with the crystalline polypropylene resin. 40 to 70% by weight of fine powder,
In the blend, a thermoplastic resin incompatible with the crystalline polypropylene resin is blended at a ratio of 105 to 300 parts by weight with respect to 100 parts by weight of the crystalline polypropylene resin, and
The water-absorbable easily peelable layer (B) is stretched in at least one axial direction.   The water-absorbable easily peelable film according to claim 1, wherein the crystallinity of the crystalline polypropylene resin is 65% or more.   The thermoplastic resin incompatible with the crystalline polypropylene resin is selected from the group consisting of polyethylene resin, styrene resin, cyclic polyolefin resin, ethylene-cyclic olefin copolymer resin, polyamide resin, polyester resin, and polycarbonate. The water-absorbing easily peelable film according to claim 1, wherein the film is at least one kind of resin.   The surface treatment agent is a surface treatment agent selected from the group consisting of a water-soluble anionic surfactant, a water-soluble cationic surfactant, and a water-soluble nonionic surfactant. The water easily peelable film according to any one of 1 to 3.   5. The water-absorbing easily peelable layer (B) further contains 0.5 to 30 parts by weight of a dispersant for inorganic fine powder with respect to 100 parts by weight of the surface-treated inorganic fine powder. The water easily peelable film according to claim 1.   The water-absorbing easily peelable film according to claim 5, wherein the dispersant is at least one of maleic acid-modified polyolefin and silanol-modified polypropylene.   7. The water-absorbing easily peelable layer (B) further contains at least one of an inorganic fine powder and an organic fine powder whose surface is not hydrophilized, in an amount of 0.1 to 30% by weight. The water easily peelable film according to claim 1. The liquid absorption volume measured by “Japan TAPPI No. 51-2000” of the water-absorbing easily peelable layer (B) is 1 to 20 ml / m ² , according to any one of claims 1 to 7 Water-absorbable easily peelable film.   The water-absorbable easily peelable film according to any one of claims 1 to 8, further comprising a water-based adhesive layer on the water-absorbable easily peelable layer (B) side of the laminated resin film.   The adhesion strength when peeling the laminated resin film from the adherend after adhering the laminated resin film to the adherend is 50 to 180 gf / 18 mm. Water-absorbable easily peelable film   11. The water-removable easily peelable film according to claim 10, wherein, when the laminated resin film is peeled from the adherend, the peeling proceeds by cohesive failure in the water-absorbable easily peelable layer (B).   12. A part of the easily absorbable release layer (B) remains on the surface of the adherend after peeling the laminated resin film from the adherend, and the residue absorbs the liquid. The water-absorbing easily peelable film described in 1.   The water-absorbable easily peelable film according to any one of claims 1 to 12, wherein the base layer (A) has a multilayer structure.   The water-absorbing easily peelable film according to any one of claims 1 to 13, further comprising a concealing layer (C).   The concealing layer (C) is selected from the group consisting of black printing or gray printing on the water-absorbing easily peelable layer (B) side surface, addition of concealing pigment to the base layer (A), and black printing insertion between the base layers (A). The water-removable easily peelable film according to claim 14, comprising at least one of the methods described above.   The water-absorbable easily peelable film according to any one of claims 1 to 15, further comprising a coat layer (D) on the surface of the base layer (A).   The wallpaper which gave the water-system adhesive to the water absorption easy peeling layer (B) side of the water easy release film as described in any one of Claims 1-16.   The label which gave the water-system adhesive to the water-absorbing easily peelable layer (B) side of the water easily peelable film as described in any one of Claims 1-16.

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