JP4917826B2 - Antifouling film for wallpaper - Google Patents

Description

Even if the vinyl chloride layer contains a high-boiling plasticizer, the present invention maintains a strong adhesive force with the base material layer, and has antifouling properties, antiblocking properties and low temperature adhesiveness. The present invention relates to an antifouling film for wall paper and a wall covering material which are excellent in water resistance.

As wallpaper used by being attached to indoor walls, closets, furniture, and the like, vinyl chloride wallpaper including a vinyl chloride layer is frequently used because of its excellent physical properties, good moldability and low cost. However, there is a problem that the vinyl chloride wallpaper is easily soiled, and that once it is soiled, it is difficult to remove the soil. In addition, since the vinyl chloride wallpaper generally contains a plasticizer, the plasticizer bleeds on the surface, and there is a problem that dirt easily occurs due to adhesion of suspended matters in the air.

Therefore, as one of the means for imparting antifouling properties to vinyl chloride wallpaper, an antifouling film having an adhesive layer formed on a base material layer made of a resin having antifouling properties is applied to the surface of the vinyl chloride layer of the vinyl chloride wallpaper. A method of laminating and bonding to each other is known. Conventionally, as such a base material layer, ethylene-vinyl acetate copolymer saponified product (EVOH) or an acrylic film has been used, and in particular, an EVOH film has been widely used.
For example, Patent Document 1 discloses an antifouling film using a transparent biaxially stretched polyester film as a base material layer. For example, Patent Document 2 uses a copolymerized polyester film as a base material layer. An antifouling film was disclosed.

Properties required for such an antifouling film include strong adhesion to the surface of the vinyl chloride layer in addition to the antifouling property of the base material layer. In particular, when the surface of the vinyl chloride wallpaper is embossed to form fine irregularities and give three-dimensional design, the antifouling film is lifted from the surface of the vinyl chloride layer, and the appearance of the vinyl chloride wallpaper is improved. Therefore, strong adhesion to the surface of the vinyl chloride layer has been required.

However, the conventional antifouling film has insufficient adhesion to the surface of the vinyl chloride layer at a low temperature, so that the antifouling film is firmly bonded to the surface of the vinyl chloride layer at a high temperature of 100 ° C. or higher. Had to be processed. However, when the vinyl chloride layer containing a plasticizer is heated to 100 ° C. or higher, there is a problem that the plasticizer bleeds out on the surface of the vinyl chloride layer.

Therefore, the present inventors disclosed in Patent Document 3 an antifouling film for wallpaper having a base material layer made of polypropylene and an adhesive layer containing a polyester polyol-acrylic copolymer, isocyanate, or the like, Among them, a method using a block isocyanate is disclosed for the purpose of exerting adhesive force even at a relatively low temperature. Such an antifouling film for wallpaper has antifouling properties and strong adhesion to the surface of the vinyl chloride layer at a low temperature, and has high antiblocking properties and excellent handleability.

However, in recent years, plasticizers with a high boiling point have been used in the vinyl chloride layer as a countermeasure against volatile organic compounds (VOC) such as toluene and xylene, and the plasticizer tends to remain in the wallpaper. Even when an antifouling film for wallpaper is used, the adhesive strength may decrease after a long period of time.
Therefore, when the vinyl chloride layer contains a high-boiling plasticizer while having antifouling properties, antiblocking properties, adhesion to the base material layer and low-temperature adhesiveness required as an antifouling film for wallpaper. Even if it exists, the antifouling film for wallpaper which the adhesive force does not fall over a long period of time was calculated | required.
Japanese Patent Application Laid-Open No. 07-232415 JP 07-290667 A JP 2004-332367 A

In view of the above situation, the present invention maintains strong adhesive strength with the base material layer even when the vinyl chloride layer contains a high-boiling plasticizer, and has antifouling properties, antiblocking properties, and low-temperature adhesion. It aims at providing the antifouling film for wallpaper and wall covering material which are excellent in property.

The antifouling film for wallpaper of the present invention is an antifouling film for wallpaper having a base material layer made of polypropylene and an adhesive layer formed on the base material layer, and the adhesive layer is made of polyester polyol-acrylic An antifouling film for wallpaper containing a copolymer, a block isocyanate, an active isocyanate, a vinyl chloride-vinyl acetate copolymer and a wax.
The present invention is described in detail below.

As a result of intensive studies, the inventors have found that when a conventional antifouling film for wallpaper is bonded to a vinyl chloride wallpaper containing a high-boiling plasticizer, the cause of the decrease in the adhesive strength of the antifouling film for wallpaper is The present inventors have found that such a plasticizer has a decrease in cohesive strength of the adhesive and a decrease in adhesion between the base material layer and the adhesive layer. As a result of further intensive studies, the present inventors have found that not only the adhesion to the wallpaper but also the adhesion between the base material layer and the adhesive layer is achieved by adding an active isocyanate to the adhesive layer in addition to the block isocyanate. Even when used for vinyl chloride wallpaper containing a high-boiling point plasticizer, it can be improved for a long time, and the decrease in the cohesive strength of the adhesive can be suppressed. It has been found that an antifouling film for wallpaper that can maintain high adhesive strength can be obtained, and the present invention has been completed.

The antifouling film for wallpaper of the present invention has a base material layer made of polypropylene and an adhesive layer formed on the base material layer.
The base material layer made of polypropylene has antifouling properties in the same manner as the resin base material made of EVOH described above, and by forming an adhesive layer made of a specific composition described later on the base material layer. Thus, an antifouling film for wallpaper having excellent antifouling properties, antiblocking properties and adhesion to a vinyl chloride layer at a low temperature can be obtained.

The antifouling film for wallpaper of the present invention has a base material layer made of polypropylene.
Although it does not specifically limit as a polypropylene which comprises the said base material layer, It is preferable that it is a crystalline polypropylene. Since this crystalline polypropylene has excellent antifouling properties as well as embossability, the synergistic effect of the embossing characteristics of crystalline polypropylene and the adhesiveness of the adhesive layer described later, for example, the vinyl chloride layer of foamed vinyl chloride wallpaper. Even if it is to the surface of this, it can adhere | attach firmly.
The crystalline polypropylene is not particularly limited, and examples thereof include a homopolypropylene resin, a block copolymer of ethylene and propylene, a copolymer of one or more monomers copolymerizable with ethylene and the like, and the like. It is done. Amorphous polypropylene does not have sufficient antifouling properties against oily dirt.
Here, the “crystallinity” refers to a property inherent in the resin, in which a raw material pellet or film is once heated and melted and then slowly cooled to be crystalline.

The base material layer may be non-stretched or stretched, but is not stretched in terms of embossability of the vinyl chloride wallpaper to which the wallpaper antifouling film of the present invention is adhered. It is preferable.

In addition, the base material layer has a flame retardant, an antifungal agent, an antibacterial agent, a moistureproof agent, an antistatic agent, an antiblocking agent, a lubricant, as long as the properties of the antifouling film for wallpaper of the present invention are not impaired. Additives such as fillers and colorants may be added, and other resins may be blended depending on the purpose.

In the antifouling film for wallpaper of the present invention, the thickness of the base material layer is not particularly limited and is appropriately determined in consideration of the performance, price, etc. of the base material layer, and is about 1 to 100 μm. Is preferred. If it is less than 1 μm, it may be easily damaged by an external impact or the like, and sufficient antifouling properties may not be exhibited. When the thickness exceeds 100 μm, the manufacturing cost increases, and the design such as the design shown on the surface of the vinyl chloride layer is concealed, or the flexibility of the antifouling film for wallpaper of the present invention is reduced. May be inferior.

In the antifouling film for wallpaper of the present invention, the adhesive layer contains a polyester polyol-acrylic copolymer, a block isocyanate, an active isocyanate, a vinyl chloride-vinyl acetate copolymer, and a wax.

The said polyester polyol-acrylic copolymer is a material which mainly comprises the said contact bonding layer, and plays the role which ensures the adhesiveness with respect to a vinyl chloride layer. Examples of such polyester polyol-acrylic copolymers include those produced using a known polyester polyol-based compound and an acryloyl group-containing hydroxy compound as main raw materials.

As said polyester polyol type compound, the well-known compound which has 2 or more of hydroxyl groups in the molecule | numerator used when manufacturing a urethane resin is mentioned, for example. Such polyester polyol compound is not particularly limited, for example, adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, Dicarboxylic acids such as pimelic acid, suberic acid, azelaic acid, ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-propanediol, 1,3 Polyester polyols obtained from polyhydric alcohols such as propanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, tripropylene glycol, trimethylolpropane, glycerin; polycaprolactone polyol, Polylactone polyester polyols such as Li β- methyl -δ- valerolactone.

In the antifouling film for wallpaper of the present invention, a known polyol compound other than the polyester polyol compound, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, Polypropylene glycol, butylene glycol, 1,4-butanediol, polybutylene glycol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, polycaprolactone, trimethylolethane, trimethylolpropane, polytrile Methylolpropane, pentaerythritol, polypentaerythritol, sorbitol, mannitol, arabitol, xylitol , Galactitol, glycerin, polyglycerin, polytetramethylene glycol and other polyhydric alcohols; polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and other polyether polyols; polybutadiene polyol or hydrogenated products thereof; polycarbonate polyols; polythioether polyols Polyacrylic ester polyols and the like can also be used.

It does not specifically limit as said acryloyl group containing hydroxy compound, For example, well-known (meth) acrylate is mentioned. Such an acryloyl group-containing hydroxy compound is not particularly limited, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 2- (meth) acrylic. Examples include leuoxyethyl-2-hydroxypropyl phthalate, glycerin di (meth) acrylate, and 2-hydroxy-3-acryloyloxypropyl (meth) acrylate. Furthermore, a compound obtained by ring-opening addition of ε-captolactone to the acryloyl group-containing hydroxy compound may be used.

The polyester polyol-acrylic copolymer may have a molecular weight increased by reacting diisocyanate. In this case, the polyester polyol-acrylic copolymer has a structure having a urethane group in part.
In addition, the polyester polyol-acrylic copolymer having a structure having a urethane group in part can be obtained by any known method, and commercially available ones can also be used.

In the antifouling film for wallpaper of the present invention, the blending amount of the polyester polyol-acrylic copolymer in the adhesive layer is not particularly limited, but the preferred lower limit is 10 parts by weight with respect to the total amount of the material constituting the adhesive layer. The upper limit is 95 parts by weight. If it is less than 10 parts by weight, strong adhesion to the surface of the vinyl chloride layer may not be obtained, and if it exceeds 95 parts by weight, the antiblocking property of the adhesive layer may be lowered. A more preferred lower limit is 30 parts by weight and an upper limit is 60 parts by weight.

The adhesive layer contains a block isocyanate as an isocyanate.
By using the block isocyanate in combination with the polyester polyol-acrylic copolymer, the softening point of the adhesive layer is lowered, and the adhesive property to the surface of the vinyl chloride layer is low even at a low temperature of about 80 to 90 ° C. can get. The reason is considered as follows. That is, the adhesive layer immediately after the formation is low because the polyester isocyanate-acrylic copolymer is not cross-linked because the block isocyanate blocked with the blocking agent does not react with the polyester polyol-acrylic copolymer. Holds the softening point. When this adhesive layer is attached to the surface of the vinyl chloride layer and subjected to hot pressing at about 90 ° C., the isocyanate is activated by the blocking agent, the polyester polyol-acrylic copolymer is crosslinked and cured, and vinyl chloride is obtained. It is thought that the adhesiveness with respect to the surface of a layer is shown.
In the present specification, the blocked isocyanate refers to an isocyanate blocked with a blocking agent that activates the isocyanate by heating.

Moreover, the said block isocyanate can also prevent the time-dependent fall of the adhesive strength with respect to the vinyl chloride layer of the antifouling film for wallpaper of this invention. This is because the polyester polyol-acrylic copolymer and the block isocyanate do not react when the adhesive layer is coated on the base material layer, and the softening point of the lowered adhesive layer can be maintained. Conceivable.

The method for producing the block isocyanate is not particularly limited. For example, the isocyanate and the blocking agent are mixed and heated to a predetermined reaction temperature, or either the isocyanate or the blocking agent is predetermined. And the like, and the other is added to the reaction temperature. In addition, when manufacturing the said block isocyanate by the latter method, generally the method of heating the isocyanate to reaction temperature and dripping the blocking agent in this is taken.
The reaction temperature is usually 50 to 80 ° C., and the blocked isocyanate is reacted with the isocyanate until the isocyanate blocked with the blocking agent reaches a target amount. Can be obtained.

The blocking agent is not particularly limited. For example, oxime systems such as acetone oxime and methyl ethyl ketone oxime; amide systems such as ε-caprolactam; active methylene systems such as dimethyl malonate and methyl acetoacetate; 3,5-dimethylpyrazole And the like. In addition, blocking agents such as phenols, alcohols, imidazoles, and ureas can also be used. These blocking agents may be used alone or in combination of two or more.

The adhesive layer contains an active isocyanate in addition to the block isocyanate as an isocyanate.
As described above, the block isocyanate has the property of lowering the softening point and improving the adhesion to the vinyl chloride layer, but has a small contribution to the adhesion to the base material layer made of polypropylene. It was. However, the above-mentioned active isocyanate is extremely excellent in adhesion to the base material layer made of polypropylene, and also reacts with the polyester polyol-acrylic copolymer to increase the resistance to the plasticizer. Even when bleed-out, the adhesive strength of the antifouling film for wallpaper can be maintained by preventing a decrease in the cohesive strength of the adhesive. In addition, unlike the block isocyanate, the active isocyanate reacts at room temperature and exhibits sufficient adhesiveness, so that the low-temperature adhesiveness of the antifouling film for wallpaper can be further improved.
In the present specification, the active isocyanate means an isocyanate that is not blocked by a blocking agent.

The content ratio of the active isocyanate to the block isocyanate is preferably in the range of 10 to 120% of active isocyanate / block isocyanate. If it is less than 10%, the amount of the active isocyanate is too small, and the adhesiveness with the base material layer may be lowered or the cohesive strength of the adhesive due to the plasticizer may be lowered. If it exceeds 120%, the softening point may increase and the low-temperature adhesiveness may decrease. More preferably, it is in the range of 20 to 70%.

Further, the content ratio of the active isocyanate to the polyester polyol-acrylic copolymer is preferably within a range of 0.5 to 8% of the active isocyanate / polyester polyol-acrylic copolymer. If it is less than 0.5%, the adhesiveness with the base material layer may be lowered, or the cohesive strength of the adhesive due to the plasticizer may be lowered. If it exceeds 8%, the low-temperature adhesiveness may be lost. More preferably, it is in the range of 1 to 6%.

The isocyanate used as the block isocyanate and the active isocyanate functions as a crosslinking agent that crosslinks the polyester polyol-acrylic copolymer. For example, a known organic used in producing a urethane resin. Isocyanates. Specifically, for example, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 3-isocyanate methyl-3,5,5 -Trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexyl-2,4-diisocyanate, methylcyclohexyl-2,6-diisocyanate, xylylene diisocyanate, 1,3-bis (Isocyanate) Aliphatic diisocyanates such as methylcyclohexane, tetramethylxylylene diisocyanate, transcyclohexane-1,4-diisocyanate, lysine diisocyanate; 2,4-toluylene diisocyanate, 2,6 -Toluylene diisocyana Diphenylmethane-4,4′-diisocyanate, 1,5′-naphthene diisocyanate, tolidine diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4′-dibenzyldi Aromatic diisocyanates such as isocyanate and 1,3-phenylene diisocyanate; lysine ester triisocyanate, triphenylmethane triisocyanate, 1,6,11-undecane triisocyanate, 1,8-isocyanate -4,4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, adducts of trimethylolpropane and toluylene diisocyanate, trimethylolpropane and 1,6-hexene Tri isocyanates such adducts, etc. and methylene diisocyanate.

The preferable lower limit of the softening point of the adhesive layer is 50 ° C., and the preferable upper limit is 180 ° C. If it is lower than 50 ° C., the anti-blocking property is lowered, and if it exceeds 180 ° C., sufficient adhesion may not be obtained when it is bonded to the surface of the vinyl chloride layer. A more preferred lower limit is 65 ° C., and a more preferred upper limit is 100 ° C.

In the antifouling film for wallpaper of the present invention, the polyester polyol compound, the acryloyl group-containing hydroxy compound and the isocyanate compound may be those commercially available as single substances, or a combination of two or more. A commercially available copolymer may be used.

The vinyl chloride-vinyl acetate copolymer plays a role of improving the adhesion to the surface of the vinyl chloride layer while ensuring the antiblocking property of the antifouling film for wallpaper of the present invention. This is considered due to the excellent antiblocking property of the vinyl chloride-vinyl acetate copolymer itself.

The blending amount of the vinyl chloride-vinyl acetate copolymer in the adhesive layer is not particularly limited, but since the adhesive strength of the adhesive layer to the surface of the vinyl chloride layer is increased, the blending of the polyester polyol-acrylic copolymer is performed. It is preferable that the same amount is blended.

Although it does not specifically limit as said wax, For example, natural systems, such as paraffin wax microcrystalline wax, synthetic systems, such as polyethylene wax and Fischer-Tropsch wax, are mentioned.

The blending amount of the wax in the adhesive layer is not particularly limited, but the preferable lower limit is 0.5 parts by weight and the upper limit is 15 parts by weight with respect to the total amount of the material constituting the adhesive layer. If it is less than 0.5 part by weight, blocking may not be sufficiently prevented, and if it exceeds 15 parts by weight, the adhesive force to the surface of the vinyl chloride layer may be greatly reduced. A more preferred lower limit is 1.5 parts by weight and an upper limit is 7.5 parts by weight.

In addition to the above-described materials, the adhesive layer constituting the antifouling film for wallpaper of the present invention may further include an antistatic agent, an anti-blocking agent, and a lubricant as long as the properties as the adhesive layer are not impaired. Additives such as fillers and colorants may be added, or other resins may be blended depending on the purpose. Examples of the resin to be blended include binary copolymers and ternary copolymers composed of polyethylene, ethylene and monomers such as acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester.

Although it does not specifically limit as thickness of the said contact bonding layer, A preferable minimum is 0.1 micrometer and an upper limit is 20 micrometers. If it is less than 0.1 μm, the adhesion of the antifouling film for wallpaper of the present invention to the surface of the vinyl chloride layer may be insufficient, and the adhesion tends to vary. If it exceeds 20 μm, the manufacturing cost will increase, and the base material layer made of polypropylene will be warped, the design such as the design shown on the surface of the vinyl chloride layer may be concealed, or the antifouling for wallpaper of the present invention The flexibility of the film may decrease.

Furthermore, the adhesive layer is preferably 0.05 times or more the thickness of the base material layer, and more preferably 0.1 times or more. If it is less than 0.05 times, the embossability imparted to the substrate layer tends to be insufficient.

The antifouling film for wallpaper of the present invention comprises, for example, a polyester polyol-acrylic copolymer, a block isocyanate, an active isocyanate, a vinyl chloride-vinyl acetate copolymer on a base material layer made of polypropylene produced by a melt extrusion method or the like. By applying an adhesive prepared by mixing a polymer and wax in a solvent by a known coating method using a doctor blade, bar coater, gravure coater, comma coater, reverse coater, etc., to form an adhesive layer Can be produced.
The solvent used in preparing the adhesive is not particularly limited. For example, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, cyclohexanone, tetrahydrofuran, toluene, Examples include xylene, dimethylformamide, dimethyl sulfoxide, butyl cellosolve; alcohols such as methanol, ethanol, and isopropyl alcohol.

Moreover, before forming an adhesive layer on the base material layer, the adhesive layer forming surface of the base material layer may be subjected to corona treatment. By performing the corona treatment, it is possible to further improve the adhesion between the base material layer and the adhesive layer. In addition, the manufacturing method of the antifouling film for wallpaper of this invention is not limited to said method, You may produce using any well-known method.

By laminating vinyl chloride wallpaper on the antifouling film for wallpaper of the present invention, a wall covering material can be obtained. Such a wall covering is also one aspect of the present invention.

As a vinyl chloride layer of the said vinyl chloride wallpaper, what is used for a well-known vinyl chloride wallpaper can be mentioned, A foam or a non-foam may be sufficient. In particular, in the present invention, even a vinyl chloride wallpaper containing a high-boiling point plasticizer can be suitably used, so that the types of wallpaper that can be used are greatly expanded.
The vinyl chloride layer may be foamed after laminating the wallpaper antifouling film of the present invention. In addition, when printing on the said vinyl chloride layer, printing ink may be used normally. For example, those obtained by mixing and dissolving colorants such as pigments and dyes, dispersants, solvents and the like in acrylic, ethylene-vinyl acetate, urethane, and cellulose resins. The printing can be performed by a known method.

When producing the wall covering material of the present invention, the method for adhering the antifouling film for wallpaper of the present invention to the surface of the vinyl chloride layer is not particularly limited, but it is preferable to adhere by the thermocompression bonding method. Since the thermocompression bonding method does not use organic solvents, solve the problems caused by organic solvents, such as impacts on the natural environment, fire hazards, health effects on workers and waste of resources. Can do.

In addition, the treatment conditions when the antifouling film for wallpaper of the present invention is adhered to the surface of the vinyl chloride layer by the thermocompression bonding method are not particularly limited, and the material constituting the adhesive layer of the antifouling film for wallpaper of the present invention Although it is determined as appropriate depending on the formulation and the like, if the antifouling film for wallpaper of the present invention is used, the treatment can be suitably performed even in a low temperature atmosphere of about 90 ° C.
Moreover, when embossing is performed on the vinyl chloride wallpaper, the embossing may be performed simultaneously with the thermocompression bonding of the wallpaper antifouling film of the present invention and the vinyl chloride layer, or may be performed in a subsequent step.

According to the present invention, by adding an active isocyanate in addition to a block isocyanate to the adhesive layer, not only the adhesiveness to the wallpaper but also the adhesiveness between the base material layer and the adhesive layer is greatly improved. Wallpaper that can maintain a high adhesive strength over a long period of time, even when used for vinyl chloride wallpaper containing a high-boiling point plasticizer. An antifouling film and a wall covering material using such an antifouling film for wallpaper can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of adhesive 27.5 parts by weight of polyester polyol and acrylic copolymer (manufactured by Nippon Polyurethane Industry Co., Ltd., “SH538”, solid content 40%) is blended uniformly with 65.9 parts by weight of methyl ethyl ketone. 1.83 parts by weight of polyisocyanate (Nippon Polyurethane Industry Co., Ltd., “Coronate 2507”), which is a block isocyanate, was added to the solution dissolved in the solution and uniformly dispersed at room temperature to prepare a mixed solution. 9 parts by weight of a vinyl chloride-vinyl acetate copolymer (“Solvine C5R” manufactured by Nissin Chemical Industry Co., Ltd.) and 0.6 part by weight of a synthetic wax (“FTP1005” manufactured by Nippon Seiki Co., Ltd.) are added to this mixed solution. And uniformly dispersed. Thereafter, 0.84 part by weight of active isocyanate (Nippon Polyurethane Industry Co., Ltd., “Coronate HX” NCO content 21%) was added and stirred sufficiently to obtain an adhesive.

(2) Production of antifouling film for wallpaper Next, the prepared adhesive was coated on a substrate made of crystalline polypropylene having a thickness of 15 μm with a bar coater and dried under conditions of 65 ° C. and 1 minute. After forming a 1.8 μm thick adhesive layer, the film was further cured at 40 ° C. for 72 hours to prepare an antifouling film for wallpaper.

(Example 2)
An antifouling film for wallpaper was prepared in the same manner as in Example 1 except that the amount of active isocyanate added was 2.0 parts by weight.

(Example 3)
An antifouling film for wallpaper was prepared in the same manner as in Example 1 except that the amount of active isocyanate added was 0.20 part by weight.

(Comparative Example 1)
An antifouling film for wallpaper was prepared in the same manner as in Example 1 except that no active isocyanate was added.

(Evaluation)
The softening point of the adhesives produced in Examples 1 to 3 and Comparative Example 1, and the change over time in the adhesive strength of the antifouling film for wallpaper, the low-temperature adhesiveness, and the plasticizer resistance were evaluated by the following methods. The results are shown in Table 1.

(Softening point of adhesive)
A No. 2 dumbbell-shaped test piece (JIS K 6251) obtained by molding the adhesives obtained in Examples and Comparative Examples and curing at 40 ° C. for 1 week was subjected to a load of 500 g / cm and about 5 ° C. The temperature at which the elongation rate becomes maximum when the temperature was increased at a rate of 1 minute was defined as the softening point.

(Change in adhesive strength over time)
The adhesive layer of the antifouling film for wallpaper obtained in the examples and the comparative examples and the vinyl chloride wallpaper were superposed on each other at 130 ° C., 0.26 MPa for 1 second using a heat gradient heat seal machine (manufactured by Toyo Seiki Seisakusho). Under conditions, heat sealing was performed with an area of 1 cm × 2.5 cm.
Next, the heat-sealed sample was left in a constant temperature bath at 50 ° C. for 72 hours, and was cut out so that the seal portion was 1 cm × 1 cm to produce a strip-shaped sample.
The portion of the strip-shaped sample thus obtained that was heat-sealed was subjected to tensile strength measurement with an autograph (AGS-100A, manufactured by Shimadzu Corporation), and the value was taken as the adhesive strength. For reference, the adhesive strength before putting in a thermostatic bath was also measured.

(Low temperature adhesion)
The adhesive layer of the antifouling film for wallpaper obtained in the examples and the comparative examples and the vinyl chloride wallpaper were superposed on each other at 90 ° C., 0.26 MPa, and 1 second using a heat gradient heat sealing machine (manufactured by Toyo Seiki Seisakusho) Under conditions, heat sealing was performed with an area of 1 cm × 2.5 cm.
Next, the heat-sealed sample was left in a constant temperature bath at 50 ° C. for 72 hours, and was cut out so that the seal portion was 1 cm × 1 cm to produce a strip-shaped sample.
The portion of the strip-shaped sample thus obtained that was heat-sealed was subjected to tensile strength measurement with an autograph (AGS-100A, manufactured by Shimadzu Corporation), and the value was taken as the adhesive strength. For reference, the adhesive strength before putting in a thermostatic bath was also measured.

(Plasticizer resistance)
The antifouling film for wallpaper obtained in Examples and Comparative Examples is immersed in dioctyl phthalate (DOP), which is generally used as a plasticizer for vinyl chloride resin, at 40 ° C. for 24 hours to dissolve the adhesive layer. It was confirmed visually whether or not.

The antifouling films for wallpaper according to Examples 1 to 3 had sufficient adhesive strength and high low-temperature adhesiveness in both the initial and aging cases. This means that the antifouling film for wallpaper does not peel off unless the force that destroys the vinyl chloride wallpaper is applied, and the antifouling film for wallpaper and the vinyl chloride wallpaper according to Examples 1 to 3 It can be said that the adhesive strength is sufficiently practical. Moreover, although the adhesive agent used for the antifouling film for wallpaper according to Examples 1 to 3 has the desired plasticizer resistance, the plasticizer resistance is improved particularly when the amount of active isocyanate added is large. It was observed.
On the other hand, it was found that the antifouling film for wallpaper according to Comparative Example 1 is particularly low in adhesive strength over time and has low plasticizer resistance.

According to the present invention, even when the vinyl chloride layer contains a high-boiling plasticizer, it maintains a strong adhesive force with the base material layer, and is antifouling, antiblocking and low temperature. An antifouling film for wall paper and a wall covering material excellent in adhesiveness can be provided.

Claims (3)

An antifouling film for wallpaper having a base material layer made of polypropylene and an adhesive layer formed on the base material layer,
The antifouling film for wallpaper, wherein the adhesive layer contains a polyester polyol-acrylic copolymer, a block isocyanate, an active isocyanate, a vinyl chloride-vinyl acetate copolymer, and a wax. The antifouling film for wallpaper according to claim 1, wherein the content ratio of the active isocyanate to the block isocyanate is 20 to 70%. A wall covering material comprising the antifouling film for wallpaper according to claim 1 or 2, and a vinyl chloride wallpaper.