JPH11348192A - Multilayer resin stretched film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the surface strength, emboss workability and ink adhesion of a film by a method wherein the surface layer of the base material layer includes specified amounts of a thermoplastic resin and of inorganic or organic fine powders and its rear surface includes specified amounts of a thermoplastic resin and of inorganic fine powders and the voids of the respective layers and of the stretched film are specified. SOLUTION: On the surface of a base material layer including 40-85 wt.% thermoplastic resin and 60-15 wt.% inorganic or organic fine powders, a surface layer including 30-90 wt.% thermoplastic resin and 70-10 wt.% inorganic or organic fine powders is arranged. At the same time, on its rear surface, a rear surface layer including 30-70 wt.% thermoplastic resin and 70-30 wt.% inorganic fine powder is arranged. Further, the voids, which are calculated by the formula; (ρ0-ρ1)/ρ0μ100, when ρ0 is the true density of the film or the layer and ρ1 is the density of the film or the layer, are set to satisfy the conditional formulae: the voids of the rear surface layer < that of the base material layer < that of the front surface layer and 5% <= the voids of a multilayer resin stretched film <= 60%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretched multilayer resin film which has excellent suitability for printing, embossing and backing and has high surface strength. The multilayer resin stretched film of the present invention can be used for various applications including architectural decorative materials having fine pores.

[0002]

2. Description of the Related Art Vinyl chloride resins such as vinyl chloride resins and vinyl chloride / vinyl acetate copolymer resins are known as thermoplastic resins having excellent printability and embossability. Vinyl chloride-based resins are widely used in industry because their hardness can be easily adjusted by a plasticizer and they are inexpensive. For this reason, many films mainly composed of a vinyl chloride resin are also used as resin films used for architectural decoration materials. However, the vinyl chloride-based resin has a problem that harmful gases such as chlorine gas and hydrogen chloride gas are generated at the time of waste treatment or fire, which causes deterioration of the incinerator and environmental pollution. There is also a problem that the interior of the room is contaminated by bleeding of the plasticizer, and the use thereof tends to be regulated worldwide.

In order to solve these problems, materials using polyolefin resins instead of vinyl chloride resins have been actively developed in recent years. However, a material using a polyolefin resin has a disadvantage that it has crystallinity. Further, in the case of a stretched film, there is also a problem that embossing is worse than that of a vinyl chloride film due to the orientation of molecules by stretching. Also,
When printing a pattern by gravure printing, silk screen printing, offset rotary printing, aqueous flexographic printing, or the like, it has been pointed out that the ink has poor adhesion, and that multicolor printing causes a shift in the pattern.

[0004] In order to improve the ink adhesion, an anchor treatment or the like is generally performed on the film surface, but this is not practical because the production cost is increased. Further, for example, in the case of performing multicolor printing using a polyolefin-based unstretched film, since the tensile strength in the printing direction is low, the printing must be performed with a low film tension, which causes the film to meander. In order to prevent such meandering, when the tension of the film is increased, the film is easily stretched to cause a dimensional change. Therefore, when printing the first color and the second and subsequent colors, the pattern is shifted and high-definition printing cannot be performed. There is also a disadvantage.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems of the prior art. That is, an object of the present invention is to provide a multilayer resin stretched film having high surface strength, excellent embossability, and good ink adhesion. Another object of the present invention is to provide an inexpensive multilayer resin stretched film which has excellent backing suitability and can be effectively used as a building decoration material or the like. Further, the present invention has no risk of causing environmental pollution,
An object of the present invention is to provide a multilayer resin stretched film that does not deteriorate an incinerator during waste treatment.
Another object of the present invention is to provide an architectural decorative material having the above characteristics.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, control the porosity of the multilayer resin stretched film and the porosity of each layer constituting the film. As a result, it has been found that excellent characteristics meeting the purpose of the present invention can be imparted to the film, and the present invention has been completed.

That is, the present invention relates to
Thermoplastic resin 30 on the surface of the base material layer (A) containing 5% by weight and 60 to 15% by weight of inorganic or organic fine powder.
~ 90% by weight and inorganic or organic fine powder 70 ~ 10
Back surface layer (C) having a surface layer (B) containing 30% by weight of a thermoplastic resin and 70-30% by weight of an inorganic fine powder on the back surface of the base material layer (A). And the porosity calculated by the equation (1) is as follows: The porosity of the back layer (B) <the porosity of the base material layer (A) <the porosity of the surface layer (C). An object of the present invention is to provide a stretched multilayer resin film satisfying a porosity of 5% ≦ porosity of the stretched multilayer resin film ≦ 60%.

[0008]

(Equation 2) ρ0: True density of film or layer ρ1: Density of film or layer

In a preferred embodiment of the present invention, the average particle diameter of the inorganic or organic fine powder of the base layer (A) is larger than the average particle diameter of the inorganic or organic fine powder of the surface layer (B). The average particle diameter of the inorganic or organic fine powder of the base layer (A) is in the range of 0.6 to 3 μm, and the average particle diameter of the inorganic or organic fine powder of the surface layer (B) is 0.1.
It is preferable that the average particle diameter of the inorganic or organic fine powder of the back surface layer (C) is in the range of 0.6 to 3 μm.

The thermoplastic resin of the surface layer (B) has a melting point lower than that of the thermoplastic resin of the base layer (A) by 10 ° C. or more, and the back layer (C) has an inorganic fine particle whose surface has been hydrophilized. It preferably contains a powder. The thermoplastic resin of the base layer (A), the surface layer (B) and the back layer (C) may be a polyolefin resin, an olefin thermoplastic elastomer, or a mixture of a polyolefin resin and an olefin thermoplastic elastomer. Mixtures can be used. The mixture of the polyolefin-based resin and the olefin-based thermoplastic elastomer is obtained by adding 5 to 5 parts by weight of the olefin-based thermoplastic elastomer to 100 parts by weight of the polyolefin-based resin.
Preferably, it is contained in a proportion of 100 parts by weight. The contact angle of the back surface layer (C) with water is preferably in the range of 10 to 80 °. The surface layer (B) can be embossed. The present invention also provides an architectural decorative material using the above-described stretched multilayer resin film.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The stretched multilayer resin film of the present invention has a surface layer (B) on the surface of the base material layer (A) and a back surface layer (C) on the back surface of the base material layer (A). The base layer (A), the surface layer (B) and the back layer (C) each contain a thermoplastic resin and an inorganic or organic fine powder.

The type of the thermoplastic resin used for the base layer (A), front layer (B) and back layer (C) is not particularly limited. For example, polyolefin resin; polyamide resin such as nylon-6, nylon-6,6, nylon-6, T; heat of polyethylene terephthalate or a copolymer thereof, polybutylene terephthalate or a copolymer thereof, or aliphatic polyester. Plastic polyester-based resin; polycarbonate, atactic polystyrene, syndiotactic polystyrene and the like can be used.

Above all, it is preferable to use a non-polar polyolefin resin. Examples of the polyolefin resin include ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1.
-Carbon number 2 such as pentene and 3-methyl-1-pentene;
And a copolymer of 2 to 5 kinds of these α-olefins. The copolymer may be a random copolymer or a block copolymer.
Specifically, the density is 0.89 to 0.97 g / cm ³ , and the melt flow rate (190 ° C., 2.16 kg load) is 1 to
Branched polyethylene, linear polyethylene at 10 g / 10 min; propylene homopolymer having a melt flow rate (230 ° C., 2.16 kg load) of 0.2 to 8 g / 10 min;
Propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 4-methyl-1-pentene copolymer,
Propylene / 3-methyl-1-pentene copolymer, poly (1-butene), poly (4-methyl-1-pentene),
A propylene / ethylene / 3-methyl-1-pentene copolymer is exemplified. Among them, propylene homopolymer, propylene / ethylene random copolymer, and high-density polyethylene are preferable because they are inexpensive and have good moldability.

For the base material layer (A), the surface layer (B) and the back surface layer (C), a thermoplastic elastomer can be particularly selected and used as the thermoplastic resin. As used herein, the term “thermoplastic elastomer” includes both a rubber component having elasticity in a molecule (soft segment) and a molecular constraint component (hard segment) for preventing plastic deformation. While the hard segment acts as the point of flow of the flowable rubber and exhibits rubber-like properties, the hard segment is melted by heating to exhibit flow characteristics as a thermoplastic resin. In the present specification, other thermoplastic resins are referred to as “thermoplastic non-elastomers”.

[0015] As the thermoplastic elastomer, a large number of thermoplastic elastomers having different types, molecular weights, arrangements, and the like of the soft segments and the hard segments are known. For example, examples of the styrene-based thermoplastic elastomer include Tuftec (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. and Lavalon (trade name) manufactured by Mitsubishi Chemical Corporation. Examples of the olefin-based thermoplastic elastomer include Mirastomer (trade name) manufactured by Mitsui Petrochemical Industries, Ltd. and Thermolan (trade name) manufactured by Mitsubishi Chemical Corporation.
As polyester-based thermoplastic elastomer, Toray
Hytrel (trade name) manufactured by DuPont, Toyobo
There is Pelprene (trade name). In addition, polyurethane thermoplastic elastomers and the like are known.

For the base material layer (A), the surface layer (B) and the back surface layer (C), one of the above thermoplastic resins may be selected and used alone. At least one species may be selected and used in combination. When two or more kinds are used in combination, it is preferable to use a mixture of a thermoplastic non-elastomer and a thermoplastic elastomer. The mixing ratio is preferably 5 to 100 parts by weight of the thermoplastic elastomer per 100 parts by weight of the thermoplastic non-elastomer. Particularly, the blending amount of the thermoplastic elastomer is 5 to 50 parts by weight in the base layer (A) and 20 to 100 parts by weight in the surface layer (B).
In terms of parts by weight, the amount of pores in the base material layer (A) is
It is preferable because the content can be increased to improve embossability, printability, and surface strength of the surface layer (B).

The same thermoplastic resin or different thermoplastic resins may be used for the base layer (A), front layer (B) and back layer (C). The thermoplastic resin can be appropriately selected according to the properties required for each layer. In order to use it as an architectural decoration material or the like, the surface layer (B) is often subjected to various types of printing, and then to a processing such as embossing. For this reason,
The surface layer (B) is required to have high-definition printability by various printing methods and ink adhesion strength capable of preventing ink dropout during embossing. In order to sufficiently meet these requirements, it is preferable to use a thermoplastic resin having a lower melting point than the base material layer (A) for the surface layer (B). In particular, it is preferable to use a thermoplastic resin having a melting point of at least 10 ° C. lower than that of the base material layer (A). The melting point of the thermoplastic resin used for the back layer (C) is not particularly limited, and may be the same as the melting point of the thermoplastic resin of the base layer (A) or the surface layer (B). May be different from the melting point of.

The kind of the organic or inorganic fine powder used for the base material layer (A), the surface layer (B) and the back layer (C) is not particularly limited. Examples of the inorganic fine powder include heavy calcium carbonate, light calcium carbonate, clay, talc, titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, and silicon oxide. Of these, heavy calcium carbonate, clay, and diatomaceous earth are preferred because they are inexpensive and have good porosity during stretching.

Examples of the organic fine powder include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, polystyrene, melamine resin, polyethylene sulphite, polyimide, polyethyl ether ketone, polyphenylene sulphite and the like. Among them, it is preferable to use incompatible fine powder having a melting point higher than that of the thermoplastic resin to be used from the viewpoint of pore formation.

For the base material layer (A), the surface layer (B) and the back surface layer (C), one of the above fine powders may be selected and used alone, or two of them may be used alone. The above may be selected and used in combination. When two or more kinds are used in combination, an organic fine powder and an inorganic fine powder may be mixed and used. Further, the same fine powder or different fine powders may be used for the base material layer (A), the surface layer (B) and the back layer (C). However, it is preferable to select a fine powder having a smaller average particle diameter than the fine powder of the surface layer (A) as the fine powder of the base material layer (B). By adjusting the average particle diameter in this way, surface protrusions are reduced and the surface smoothness and the like are improved, and as a result, higher-definition printing becomes possible.

The preferable range of the average particle size of the fine powder used in the base material layer (A) is 0.6 to 3 μm. If the average particle diameter is 0.6 μm or more, more sufficient voids (voids) can be formed by stretching. If the average particle size is 3 μm or less, the pores can be controlled to an appropriate size, and the occurrence of wrinkles in the film can be more effectively prevented. The preferable range of the average particle diameter of the fine powder used for the surface layer (B) is 0.1 to 2 μm. By setting the average particle diameter within the above range, fine cracks can be formed on the surface to improve the adhesiveness of the ink, and white spots during printing can be more effectively prevented. Further, in the surface layer (B), the content of coarse particles having a particle diameter of 44 μm or more which causes surface projections of the multilayer resin stretched film is preferably set to 10 ppm or less.

The preferable range of the average particle size of the fine powder used for the back layer (C) is 0.6 to 3 μm for the same reason as that for the fine powder of the base material layer (A). However, it is preferable to use an inorganic fine powder whose surface has been subjected to a hydrophilic treatment for the back surface layer (C). The hydrophilization treatment can be performed by treating the inorganic compound with a water-soluble anionic or cationic or nonionic polymer surfactant having an average molecular weight of 1,000 to 150,000 when wet-milling. In addition, it can also be carried out by treating the inorganic compound with an anion, a cation or a non-ionic antistatic agent during wet pulverization. Both of these processes may be performed in two stages. Preferred examples of the hydrophilized inorganic fine powder include those described in JP-A-7-300568.

The above two-stage treatment is carried out by applying an average particle diameter of 0.6 to 3
The use of the hydrophilic fine inorganic powder applied to the fine inorganic powder of μm makes it possible to adjust the contact angle (water contact angle) of the back surface layer (C) to water within a preferable range. The preferred range of the water contact angle is 10 to 80 °, and the more preferred range is 20 to 80 °.
70 °. If the contact angle with water is less than 10 °, the penetration rate of water becomes too high, and when an aqueous paste is used, the paste component itself permeates too much inside. For this reason, the amount of glue to be applied increases and the production cost increases. On the other hand, if the contact angle exceeds 80 °, the permeation rate of water is low and the drying property of the paste is low, so that the productivity is reduced and the production cost is increased. Further, since the permeation of the adhesive component itself is small, the adhesiveness between the adhesive and the stretched multilayer resin film is also reduced. In addition, the water contact angle in this specification shows what was measured using the contact angle meter (Kyowa Interface Chemical Co., Ltd. make, model CA-D).

As described above, by using the inorganic fine powder subjected to the hydrophilic treatment for the back layer (C) and improving the wettability with water, the adsorbability of the aqueous adhesive or the like to the back layer (C) is improved. And drying properties are improved. Further, by using the inorganic fine powder treated with the antistatic agent, the back surface layer (C) can be provided with an antistatic property. Therefore, it is possible to obtain a stretched multilayer resin film which is free from charging trouble at the time of applying an adhesive or a pressure-sensitive adhesive such as a backing and has excellent drying properties and excellent adhesiveness.

In order to produce the stretched multilayer resin film of the present invention, the thermoplastic resin and the fine powder are mixed to form each layer. In the base material layer (A), the thermoplastic resin is
８５85% by weight, and 60-15% by weight of inorganic or organic fine powder. If the amount of the fine powder exceeds 60% by weight, it is difficult to form a multilayer resin stretched film having a uniform thickness, and if the amount is less than 15% by weight, the amount of pores formed by stretching is small, so that embossability is poor. turn into.

In the surface layer (B), a thermoplastic resin is used in an amount of 30 to
90% by weight, and 70 to 10% by weight of inorganic or organic fine powder. When the amount of the fine powder exceeds 70% by weight, it is difficult to uniformly stretch the film, and the surface film of the produced multilayer resin stretched film is liable to be cracked, which is not practical. If the amount of the fine powder is less than 10% by weight, ink adhesion will be poor. In the back surface layer (C), 30 to 70% by weight of a thermoplastic resin and 70 to 30% by weight of an inorganic or organic fine powder are blended. If the amount of the fine powder exceeds 70% by weight, it becomes difficult to form a multilayer resin stretched film having a uniform thickness. In particular, the inorganic fine powder subjected to the hydrophilization treatment is preferably used in an amount of 10% by weight or more for exhibiting hydrophilicity.

When the fine powder is mixed and kneaded in the thermoplastic resin, a dispersant, an antioxidant, a compatibilizer, a flame retardant, an ultraviolet stabilizer, a coloring pigment, and the like can be added as required. In particular, it is preferable that the base layer (A) and the surface layer (B) are colored to a desired color by using an inorganic or organic coloring pigment. When the stretched multilayer resin film of the present invention is used as a durable material, it is preferable to add an antioxidant, an ultraviolet stabilizer and the like. Furthermore, when an organic fine powder is used, the type and amount of the compatibilizer are important because they determine the particle form of the organic fine powder. Preferred examples of the compatibilizer include maleic acid-modified polypropylene (trade name: Umex, manufactured by Sanyo Chemical Industries, Ltd.). The amount of the compatibilizer is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the organic fine powder.

The multilayer resin stretched film of the present invention is produced by using a blend containing a thermoplastic resin, fine powder and other additional components. The thickness of each layer of the multilayer stretched resin film to be produced is as follows: surface layer (B) / base layer (A) / backside layer (C) = (1-3) / (8-4) / (1-3) It is preferable to prepare so that By setting the thickness of each layer in this range, a multilayer resin stretched film having excellent surface strength, printability, embossability, and emboss return can be obtained. When the thickness configuration of the base material layer (A) is 4 or less, it is not preferable because embossing is deteriorated.

The stretched multilayer resin film of the present invention can be manufactured by combining various methods known to those skilled in the art. The stretched multilayer resin film produced by any method is included in the scope of the present invention as long as it satisfies the conditions described in claim 1.
Therefore, the base material layer (A), the surface layer (B) and the back surface layer (C) may be manufactured by separately stretching and then laminating, or the base material layer (A), the surface layer ( It may be manufactured by laminating B) and the back layer (C) and then stretching them together. Further, it may be manufactured by laminating the base material layer (A) and the surface layer (B) and then stretching, and then laminating the stretched or unstretched back layer (C). These methods can be appropriately combined.

A preferred production method includes a step of laminating the base material layer (A), the front surface layer (B) and the back surface layer (C) and then stretching them together. Compared to the case of separately stretching and laminating, it is simpler and the cost is lower. Further, the control of the holes formed in the base material layer (A) and the surface layer (B) becomes easier. In particular, the base layer (A) is controlled so that more holes are formed by stretching than the surface layer (B), and the base layer (A) effectively functions as a layer capable of improving the embossability. Is preferred.

For stretching, various known methods can be used. The stretching temperature may be set to be equal to or higher than the glass transition temperature of the thermoplastic resin to be used in the case of the non-crystalline resin, or to be equal to or lower than the melting point of the crystal part in the case of the crystalline resin. it can. The stretching temperature is preferably at least 5 ° C. lower than the melting point of the thermoplastic resin of the surface layer (B), and at least 15 ° C. lower than the melting point of the thermoplastic resin of the base layer (A). Unless the temperature is set in this manner, the sheet is stuck on the roll surface, and the sticking pattern appears on the surface of the multilayer resin stretched film, particularly when performing inter-roll stretching, which is not preferable. Further, the number of cracks formed in the surface layer (B) is reduced, so that the ink adhesion is reduced.

Specific examples of the stretching method include inter-roll stretching using a peripheral speed difference between roll groups, and clip stretching using a tenter oven. Among them, uniaxial roll stretching is preferable because the stretching ratio can be arbitrarily adjusted and the size and number of pores formed can be controlled. In particular, by uniaxially stretching all the layers, holes and cracks are formed in the shape of a football, so that a larger number of fine holes can be formed than in biaxial stretching. In addition, since the resin is stretched and oriented in the flow direction of the film, it is possible to obtain a multilayer resin stretched film having higher tensile strength and less dimensional change due to tension during printing or processing than a non-stretched film.
Furthermore, since the orientation of the resin is less than in biaxial stretching,
A multilayer resin stretched film having good resistance to emboss return can be obtained.

The stretching ratio is not particularly limited, and is appropriately determined in consideration of the intended use of the stretched multilayer resin film of the present invention, the characteristics of the thermoplastic resin used, and the like. For example, when a propylene homopolymer or a copolymer thereof is used as the thermoplastic resin, when it is stretched in one direction, about 1.2 to 12
2 times, preferably 2 to 7 times. Further, heat treatment at a high temperature is performed as necessary. The stretching speed is preferably from 20 to 350 m / min.

The stretched multilayer resin film of the present invention has a porous structure having fine pores, and the porosity calculated by the above formula (1) is in the range of 5 to 60%. If the porosity is less than 5%, embossing will be poor. On the other hand, if the porosity exceeds 60%, the material strength of the film decreases, and the surface is easily broken by cellophane tape or the like. The porosity of each layer must satisfy the relationship of back layer (B) <base layer (A) <surface layer (C). While not being bound by any theory, by satisfying such porosity conditions, it becomes possible to absorb the thermal deformation of the resin portion that occurs during embossing, and to improve the embossability and return resistance. Is considered to be good. Further, since fine cracks are formed in the surface layer (B), printability is improved.

In formula (1), ρ0 represents the true density of the stretched multilayer resin film or each layer, and ρ1 represents the density of the stretched multilayer resin film or each layer. Unless the material before stretching contains a large amount of air, the true density is approximately equal to the density before stretching. The density of the multilayer resin stretched film of the present invention,
It is preferably in the range of 0.60 to 1.20 g / cm ³ .

The stretched multilayer resin film of the present invention may be used as it is, or may be used after being laminated on another thermoplastic film or the like. When further laminating, it can be laminated on a transparent or opaque film such as a polyester film, a polyamide film and a polyolefin film. The thickness of the stretched multilayer resin film of the present invention is not particularly limited. For example, 30-4
The thickness can be adjusted to 00 μm, preferably 60 to 200 μm. Further, by laminating the film with another film as described above, the overall thickness can be reduced to about 1 mm.

The stretched multilayer resin film of the present invention can be used for various applications. For example, it is useful for wallpaper for architectural decoration, decorative paper for decorative plywood, flooring, interior materials for automobiles, tack labels that have been subjected to adhesive processing, and the like.

The surface layer (B) of the stretched multilayer resin film of the present invention can be printed according to the purpose of use. The type and method of printing are not particularly limited. For example, printing can be performed using a known printing means such as gravure printing using an ink in which a pigment is dispersed in a known vehicle, aqueous flexo, silk screen, UV offset rotary printing, or the like. In addition, printing can be performed by metal deposition, gloss printing, mat printing, or the like. The pattern to be printed can be appropriately selected from natural patterns such as stones, wood, lattices, polka dots, and floral patterns, abstract patterns, characters, and the like.

The multilayer resin stretched film of the present invention can be embossed. Embossing is generally performed after printing, but printing may be further performed after embossing. The embossing can be performed, for example, by using a known various press such as a lithographic press, a roll embossing machine, or an embossing machine to shape the concavo-convex shape of the embossing plate by heat or pressure. The roll embossing method is a method in which the concavo-convex shape of a cylindrical embossing plate is formed on a target material by hot pressing. The hot pressing is performed by heating the resin used for the surface layer (B) of the multilayer resin stretched film between the heat deformation temperature and the melting temperature, and pressing the embossing plate against the surface of the multilayer resin stretched film. After shaping, cooling is performed to fix the shape. As the heating method, for example, a method such as infrared irradiation, hot air blowing, conduction heat from a heating roller, dielectric heating, or the like is used. It should be noted that embossing can be performed simultaneously with film formation before or after stretching without using an embossing machine.

When the stretched multilayer resin film of the present invention is used as a decorative plywood, the design can be improved by wiping after embossing and filling the recess with wiping ink. In particular, it is suitable for reproducing the appearance of the conduit portion of the grain.

It is desirable to form a surface protective layer made of a transparent resin layer on the outermost layer. The surface protective layer has a function of protecting the surface layer and imparting a three-dimensional effect to the design such as a pattern or emboss of the lower layer. Therefore, the surface protective layer is particularly useful when the stretched multilayer resin film of the present invention is used as a decorative board or wallpaper. The surface protective layer can be formed by coating or bonding. In order to further improve the surface physical properties, it is preferable to use a colorless transparent or colored transparent resin having excellent surface physical properties such as weather resistance, abrasion resistance and stain resistance. Preferred as such a resin is
For example, various types of acrylates, polyesters and the like, ionizing radiation curable resins, polyurethanes, two-pack curable resins such as unsaturated polyesters, fluororesins, polysiloxane resins, and the like. The surface protective layer may contain known antibacterial agents, antifungal agents, fragrances and the like.

Other materials can be attached to the back surface of the multilayer resin stretched film which has been subjected to various printing and embossing processes. For example, when used as wallpaper or flooring, backing paper or the like can be attached. The material used for the backing is not particularly limited, for example, thin paper, paper such as kraft paper, inorganic fiber such as glass fiber and carbon fiber, woven fabric, nonwoven fabric, resin film or sheet, metal foil, and simple substance such as woody material. Alternatively, a composite material obtained by laminating the above materials by a known means such as adhesion or heat fusion can be used.

In addition, a laminated resin stretched film of the present invention is laminated on a metal plate such as an iron plate or an aluminum plate using an adhesive or heat fusion to produce a resin decorative plate lined with a plate-like material. Can also. Further, a resin decorative plywood can also be manufactured by laminating the multilayer resin stretched film of the present invention on various types of wood plywood with an adhesive. Furthermore, a tack seal type wallpaper can be manufactured by laminating an adhesive layer or a laminate of the adhesive layer and a release sheet on the backing.

[0044]

The present invention will be described more specifically with reference to the following Examples, Comparative Examples and Test Examples. The materials, usage amounts, ratios, operations, and the like shown below can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. The materials used are summarized in the table below. In addition, MFR in a table | surface means a melt flow rate.

[0045]

[Table 1]

(Examples and Comparative Examples) According to the following procedure, the stretched multilayer resin film of the present invention (Examples 1 to 5)
And a multilayer stretched resin film for comparison (Comparative Examples 1 to 3)
Was manufactured, and wallpaper was manufactured using these. Table 2
Table 1 summarizes the types and amounts of materials used in the production of each film, stretching conditions, and the state of the produced films. Formulations [A], [B] and [C] were prepared by mixing thermoplastic resin, elastomer and fine powder. These compounds were melt-kneaded with three extruders set at 250 ° C., respectively, and the compound [B] was laminated on the front side of the compound [A] and the compound [C] was laminated on the back side in a die. Then, the resultant was extruded and cooled to 70 ° C. by a cooling device to obtain a three-layer unstretched sheet. After heating this sheet to a predetermined temperature, it was stretched at a predetermined ratio between rolls in the longitudinal direction. Next, a corona treatment of 50 W / m ² · min was performed on both surfaces of the obtained stretched film using a discharge treatment machine (manufactured by Kasuga Electric Co., Ltd.) to obtain a multilayer resin stretched film having a three-layer structure. Porosity of each layer of the obtained multilayer resin stretched film,
The overall porosity, thickness and density were as shown in Table 2.

Next, gravure printing of a floral pattern (ink: manufactured by Toyo Ink Co., Ltd., trade name: “CCST”) was applied to the surface layer (B) of the stretched multilayer resin film, and then 100 ° C.
Was embossed with a heated embossing roll. Further, a UV curable resin (manufactured by Dainichi Seika) was applied on the surface so as to be 3 g / m ^2, and a high-pressure mercury lamp (8
(0 W, 10 m / min). Furthermore, 5 g of a water-soluble starch-based paste is applied to the back layer (C) of the multilayer resin stretched film.
/ M ² using a roll coater, and 8
After performing a drying treatment in a dryer set at 0 ° C., a release paper was backed to produce a wallpaper.

[0048]

[Table 2]

(Test Example) The following tests and evaluations were performed on the produced multilayer stretched resin film and wallpaper.

1) Embossability (hanging) The embossing formed on the surface of the wallpaper was visually observed and evaluated according to the following criteria. ：: Three-dimensional effect and sharpness △: Slightly lacking sharpness but three-dimensionality, no problem in practical use ×: Neither depth nor sharpness. Unavailable for practical use

2) Emboss return resistance The backing paper of the wallpaper was removed, and an appropriate amount of water was applied to the starch paste-coated surface with a brush, and the resultant was adhered to the surface of the plywood to prevent air from entering, thereby obtaining a wall plate. Immediately superimpose the two wall plates so that the surfaces on which the wallpapers are stuck are in contact with each other, and place them in a dryer at 60 ° C. for 30 minutes.
A pressurization of 0 kg / m ² was performed for 3 minutes. Thereafter, the wallboard was taken out, and the state change of the emboss was visually observed and evaluated according to the following criteria. ：: No change ：: The three-dimensional effect was slightly reduced, but there was no problem in practical use. Chipping, apparent embossing return, and practical problem x: Emboss is almost completely lost and cannot be used practically

3) Adhesiveness of ink on surface layer (B) Adhesive tape (trade name "Cellotape" manufactured by Nichiban Co., Ltd.) is applied to the surface of the gravure-printed wallpaper and pressed sufficiently. The film was peeled off at a constant speed in a direction at 90 degrees to the adhesive surface. The manner in which ink was removed from the wallpaper surface was visually observed and evaluated according to the following criteria. ：: The ink was not peeled at all. ○: The material portion of the film was destroyed, but there was no problem in practical use. ：: Tape There is resistance at the time of peeling, but most of the ink is peeled off, and there is a problem in practical use.
Unavailable for practical use

4) Surface Strength of Surface Layer (B) An adhesive tape (trade name “Cellotape” manufactured by Nichiban Co., Ltd.) was applied to the surface layer (B) of the multilayer resin stretched film, and pressed sufficiently with a finger. Use a tensile tester (manufactured by Shimadzu Corporation: trade name "Autograph") to apply 100
Peeling was performed at a speed of 0 mm / min. The state change of the surface layer (B) after peeling was observed with the naked eye and evaluated according to the following criteria. 変 化: No change ：: Very slight fluffing of the surface, but no problem in practical use △: Many fluffing of the surface There is a problem in practical use. ×: Peeling occurs from inside the film layer, and it cannot be used practically.

5) Water contact angle of back surface layer (C) The contact angle of the back surface layer (C) of the multilayer resin stretched film was measured using a contact angle meter (made by Kyowa Interface Chemical Co., Ltd .: Model CA- D).

6) Paste Drying Property of Back Layer (C) Starch paste (manufactured by Tokiwa Chemical Co.) is coated on the back layer (C) of the stretched multilayer resin film using a rod bar so that the solid content is 5 g / m ^2. Then, the time required for the coated starch paste to change its surface gloss was measured.

7) Adhesive Adhesion of Backside Layer (C) Adhesive tape (trade name “Cellotape” manufactured by Nichiban Co., Ltd.) is applied to the dried coated surface of the starch paste of 6), and after sufficiently pressing, the adhesive is applied. The tape was peeled off at a constant speed in a direction at 90 degrees to the adhesive surface. The manner in which the glue was removed was visually observed and evaluated according to the following criteria. ：: The adhesive is cohesively broken. ○: The material portion of the film is destroyed. ：: There is resistance when the tape is peeled off, but the glue is partially peeled off from the back layer (C), and there is a practical problem. X: Tape peeling Occasionally there is no resistance and the entire amount of glue peels off from the back layer (C), making it impractical

The results of the above tests are summarized in the following table.

[Table 3]

As is clear from Table 3, the multilayer resin stretched film of the present invention has an embossability, an emboss return resistance, an ink adhesion and a surface strength of the surface layer (B), and a water contact angle of the back layer (C). , Glue drying and glue adhesion are all good (Examples 1 to 5). On the other hand, a film in which the porosity of each layer does not satisfy the relationship of (B) <(A) <(C) or a film in which the total porosity is out of the range of 5 to 60% is obtained. Is inferior and not practical.

[0059]

The multilayer resin stretched film of the present invention is excellent in printing suitability, embossing suitability and backing suitability, and has high surface strength. Therefore, the stretched multilayer resin film of the present invention can be effectively provided for various uses including architectural decoration materials.

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[Procedure amendment]

[Submission date] July 6, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Multi-layer stretched resin film

[Claims]

(Equation 1) ρ0: True density of film or layer ρ1: Density of film or layer

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretched multilayer resin film which has excellent suitability for printing, embossing and backing and has high surface strength. The multilayer resin stretched film of the present invention can be used for various applications including architectural decorative materials having fine pores.

[0002]

2. Description of the Related Art Vinyl chloride resins such as vinyl chloride resins and vinyl chloride / vinyl acetate copolymer resins are known as thermoplastic resins having excellent printability and embossability. Vinyl chloride-based resins are widely used in industry because their hardness can be easily adjusted by a plasticizer and they are inexpensive. For this reason, many films mainly composed of a vinyl chloride resin are also used as resin films used for architectural decoration materials. However, the vinyl chloride-based resin has a problem that harmful gases such as chlorine gas and hydrogen chloride gas are generated at the time of waste treatment or fire, which causes deterioration of the incinerator and environmental pollution. There is also a problem that the interior of the room is contaminated by bleeding of the plasticizer, and the use thereof tends to be regulated worldwide.

In order to solve these problems, materials using polyolefin resins instead of vinyl chloride resins have been actively developed in recent years. However, a material using a polyolefin resin has a disadvantage that it has crystallinity. Further, in the case of a stretched film, there is also a problem that embossing is worse than that of a vinyl chloride film due to the orientation of molecules by stretching. Also,
When printing a pattern by gravure printing, silk screen printing, offset rotary printing, aqueous flexographic printing, or the like, it has been pointed out that the ink has poor adhesion, and that multicolor printing causes a shift in the pattern.

[0004] In order to improve the ink adhesion, an anchor treatment or the like is generally performed on the film surface, but this is not practical because the production cost is increased. Further, for example, in the case of performing multicolor printing using a polyolefin-based unstretched film, since the tensile strength in the printing direction is low, the printing must be performed with a low film tension, which causes the film to meander. In order to prevent such meandering, when the tension of the film is increased, the film is easily stretched to cause a dimensional change. Therefore, when printing the first color and the second and subsequent colors, the pattern is shifted and high-definition printing cannot be performed. There is also a disadvantage.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems of the prior art. That is, an object of the present invention is to provide a multilayer resin stretched film having high surface strength, excellent embossability, and good ink adhesion. Another object of the present invention is to provide an inexpensive multilayer resin stretched film which has excellent backing suitability and can be effectively used as a building decoration material or the like. Further, the present invention has no risk of causing environmental pollution,
An object of the present invention is to provide a multilayer resin stretched film that does not deteriorate an incinerator during waste treatment.
Another object of the present invention is to provide an architectural decorative material having the above characteristics.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, control the porosity of the multilayer resin stretched film and the porosity of each layer constituting the film. As a result, it has been found that excellent characteristics meeting the purpose of the present invention can be imparted to the film, and the present invention has been completed.

That is, the present invention relates to
Thermoplastic resin 30 on the surface of the base material layer (A) containing 5% by weight and 60 to 15% by weight of inorganic or organic fine powder.
~ 90% by weight and inorganic or organic fine powder 70 ~ 10
Back surface layer (C) having a surface layer (B) containing 30% by weight of a thermoplastic resin and 70-30% by weight of an inorganic fine powder on the back surface of the base material layer (A). And the porosity calculated by the formula (1) is as follows: The porosity of the surface layer (B) <the porosity of the base material layer (A) <the porosity of the back surface layer (C). An object of the present invention is to provide a stretched multilayer resin film satisfying a porosity of 5% ≦ porosity of the stretched multilayer resin film ≦ 60%.

[0008]

(Equation 2) ρ0: True density of film or layer ρ1: Density of film or layer

In a preferred embodiment of the present invention, the average particle diameter of the inorganic or organic fine powder of the base layer (A) is larger than the average particle diameter of the inorganic or organic fine powder of the surface layer (B). The average particle diameter of the inorganic or organic fine powder of the base layer (A) is in the range of 0.6 to 3 μm, and the average particle diameter of the inorganic or organic fine powder of the surface layer (B) is 0.1.
It is preferable that the average particle diameter of the inorganic or organic fine powder of the back surface layer (C) is in the range of 0.6 to 3 μm.

The thermoplastic resin of the surface layer (B) has a melting point lower than that of the thermoplastic resin of the base layer (A) by 10 ° C. or more, and the back layer (C) has an inorganic fine particle whose surface has been hydrophilized. It preferably contains a powder. The thermoplastic resin of the base layer (A), the surface layer (B) and the back layer (C) may be a polyolefin resin, an olefin thermoplastic elastomer, or a mixture of a polyolefin resin and an olefin thermoplastic elastomer. Mixtures can be used. The mixture of the polyolefin-based resin and the olefin-based thermoplastic elastomer is obtained by adding 5 to 5 parts by weight of the olefin-based thermoplastic elastomer to 100 parts by weight of the polyolefin-based resin.
Preferably, it is contained in a proportion of 100 parts by weight. The contact angle of the back surface layer (C) with water is preferably in the range of 10 to 80 °. The surface layer (B) can be embossed. The present invention also provides an architectural decorative material using the above-described stretched multilayer resin film.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The stretched multilayer resin film of the present invention has a surface layer (B) on the surface of the base material layer (A) and a back surface layer (C) on the back surface of the base material layer (A). The base layer (A), the surface layer (B) and the back layer (C) each contain a thermoplastic resin and an inorganic or organic fine powder.

The type of the thermoplastic resin used for the base layer (A), front layer (B) and back layer (C) is not particularly limited. For example, polyolefin resin; polyamide resin such as nylon-6, nylon-6,6, nylon-6, T; heat of polyethylene terephthalate or a copolymer thereof, polybutylene terephthalate or a copolymer thereof, or aliphatic polyester. Plastic polyester-based resin; polycarbonate, atactic polystyrene, syndiotactic polystyrene and the like can be used.

Above all, it is preferable to use a non-polar polyolefin resin. Examples of the polyolefin resin include ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1.
-Carbon number 2 such as pentene and 3-methyl-1-pentene;
And a copolymer of 2 to 5 kinds of these α-olefins. The copolymer may be a random copolymer or a block copolymer.
Specifically, the density is 0.89 to 0.97 g / cm ³ , and the melt flow rate (190 ° C., 2.16 kg load) is 1 to
Branched polyethylene, linear polyethylene at 10 g / 10 min; propylene homopolymer having a melt flow rate (230 ° C., 2.16 kg load) of 0.2 to 8 g / 10 min;
Propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 4-methyl-1-pentene copolymer,
Propylene / 3-methyl-1-pentene copolymer, poly (1-butene), poly (4-methyl-1-pentene),
A propylene / ethylene / 3-methyl-1-pentene copolymer is exemplified. Among them, propylene homopolymer, propylene / ethylene random copolymer, and high-density polyethylene are preferable because they are inexpensive and have good moldability.

For the base material layer (A), the surface layer (B) and the back surface layer (C), a thermoplastic elastomer can be particularly selected and used as the thermoplastic resin. As used herein, the term “thermoplastic elastomer” includes both a rubber component having elasticity in a molecule (soft segment) and a molecular constraint component (hard segment) for preventing plastic deformation. While the hard segment acts as the point of flow of the flowable rubber and exhibits rubber-like properties, the hard segment is melted by heating to exhibit flow characteristics as a thermoplastic resin. In the present specification, other thermoplastic resins are referred to as “thermoplastic non-elastomers”.

[0015] As the thermoplastic elastomer, a large number of thermoplastic elastomers having different types, molecular weights, arrangements, and the like of the soft segments and the hard segments are known. For example, examples of the styrene-based thermoplastic elastomer include Tuftec (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. and Lavalon (trade name) manufactured by Mitsubishi Chemical Corporation. Examples of the olefin-based thermoplastic elastomer include Mirastomer (trade name) manufactured by Mitsui Petrochemical Industries, Ltd. and Thermolan (trade name) manufactured by Mitsubishi Chemical Corporation.
As polyester-based thermoplastic elastomer, Toray
Hytrel (trade name) manufactured by DuPont, Toyobo
There is Pelprene (trade name). In addition, polyurethane thermoplastic elastomers and the like are known.

For the base material layer (A), the surface layer (B) and the back surface layer (C), one of the above thermoplastic resins may be selected and used alone. At least one species may be selected and used in combination. When two or more kinds are used in combination, it is preferable to use a mixture of a thermoplastic non-elastomer and a thermoplastic elastomer. The mixing ratio is preferably 5 to 100 parts by weight of the thermoplastic elastomer per 100 parts by weight of the thermoplastic non-elastomer. Particularly, the blending amount of the thermoplastic elastomer is 5 to 50 parts by weight in the base layer (A) and 20 to 100 parts by weight in the surface layer (B).
In terms of parts by weight, the amount of pores in the base material layer (A) is
It is preferable because the content can be increased to improve embossability, printability, and surface strength of the surface layer (B).

The same thermoplastic resin or different thermoplastic resins may be used for the base layer (A), front layer (B) and back layer (C). The thermoplastic resin can be appropriately selected according to the properties required for each layer. In order to use it as an architectural decoration material or the like, the surface layer (B) is often subjected to various types of printing, and then to a processing such as embossing. For this reason,
The surface layer (B) is required to have high-definition printability by various printing methods and ink adhesion strength capable of preventing ink dropout during embossing. In order to sufficiently meet these requirements, it is preferable to use a thermoplastic resin having a lower melting point than the base material layer (A) for the surface layer (B). In particular, it is preferable to use a thermoplastic resin having a melting point of at least 10 ° C. lower than that of the base material layer (A). The melting point of the thermoplastic resin used for the back layer (C) is not particularly limited, and may be the same as the melting point of the thermoplastic resin of the base layer (A) or the surface layer (B). May be different from the melting point of.

The kind of the organic or inorganic fine powder used for the base material layer (A), the surface layer (B) and the back layer (C) is not particularly limited. Examples of the inorganic fine powder include heavy calcium carbonate, light calcium carbonate, clay, talc, titanium oxide, barium sulfate, zinc oxide, magnesium oxide, diatomaceous earth, and silicon oxide. Of these, heavy calcium carbonate, clay, and diatomaceous earth are preferred because they are inexpensive and have good porosity during stretching.

Examples of the organic fine powder include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, polystyrene, melamine resin, polyethylene sulphite, polyimide, polyethyl ether ketone, polyphenylene sulphite and the like. Among them, it is preferable to use incompatible fine powder having a melting point higher than that of the thermoplastic resin to be used from the viewpoint of pore formation.

For the base material layer (A), the surface layer (B) and the back surface layer (C), one of the above fine powders may be selected and used alone, or two of them may be used alone. The above may be selected and used in combination. When two or more kinds are used in combination, an organic fine powder and an inorganic fine powder may be mixed and used. Further, the same fine powder or different fine powders may be used for the base material layer (A), the surface layer (B) and the back layer (C). However, it is preferable to select a fine powder having a smaller average particle diameter than the fine powder of the base material layer (A) as the fine powder of the surface layer (B). By adjusting the average particle diameter in this way, surface protrusions are reduced and the surface smoothness and the like are improved, and as a result, higher-definition printing becomes possible.

The preferable range of the average particle size of the fine powder used in the base material layer (A) is 0.6 to 3 μm. If the average particle diameter is 0.6 μm or more, more sufficient voids (voids) can be formed by stretching. If the average particle size is 3 μm or less, the pores can be controlled to an appropriate size, and the occurrence of wrinkles in the film can be more effectively prevented. The preferable range of the average particle diameter of the fine powder used for the surface layer (B) is 0.1 to 2 μm. By setting the average particle diameter within the above range, fine cracks can be formed on the surface to improve the adhesiveness of the ink, and white spots during printing can be more effectively prevented. Further, in the surface layer (B), the content of coarse particles having a particle diameter of 44 μm or more which causes surface projections of the multilayer resin stretched film is preferably set to 10 ppm or less.

The preferable range of the average particle size of the fine powder used for the back layer (C) is 0.6 to 3 μm for the same reason as that for the fine powder of the base material layer (A). However, it is preferable to use an inorganic fine powder whose surface has been subjected to a hydrophilic treatment for the back surface layer (C). The hydrophilization treatment can be performed by treating the inorganic compound with a water-soluble anionic or cationic or nonionic polymer surfactant having an average molecular weight of 1,000 to 150,000 when wet-milling. In addition, it can also be carried out by treating the inorganic compound with an anion, a cation or a non-ionic antistatic agent during wet pulverization. Both of these processes may be performed in two stages. Preferred examples of the hydrophilized inorganic fine powder include those described in JP-A-7-300568.

The above two-stage treatment is carried out by applying an average particle diameter of 0.6 to 3
The use of the hydrophilic fine inorganic powder applied to the fine inorganic powder of μm makes it possible to adjust the contact angle (water contact angle) of the back surface layer (C) to water within a preferable range. The preferred range of the water contact angle is 10 to 80 °, and the more preferred range is 20 to 80 °.
70 °. If the contact angle with water is less than 10 °, the penetration rate of water becomes too high, and when an aqueous paste is used, the paste component itself permeates too much inside. For this reason, the amount of glue to be applied increases and the production cost increases. On the other hand, if the contact angle exceeds 80 °, the permeation rate of water is low and the drying property of the paste is low, so that the productivity is reduced and the production cost is increased. Further, since the permeation of the adhesive component itself is small, the adhesiveness between the adhesive and the stretched multilayer resin film is also reduced. In addition, the water contact angle in this specification shows what was measured using the contact angle meter (Kyowa Interface Chemical Co., Ltd. make, model CA-D).

As described above, by using the inorganic fine powder subjected to the hydrophilic treatment for the back layer (C) and improving the wettability with water, the adsorbability of the aqueous adhesive or the like to the back layer (C) is improved. And drying properties are improved. Further, by using the inorganic fine powder treated with the antistatic agent, the back surface layer (C) can be provided with an antistatic property. Therefore, it is possible to obtain a stretched multilayer resin film which is free from charging trouble at the time of applying an adhesive or a pressure-sensitive adhesive such as a backing and has excellent drying properties and excellent adhesiveness.

In order to produce the stretched multilayer resin film of the present invention, the thermoplastic resin and the fine powder are mixed to form each layer. In the base material layer (A), the thermoplastic resin is
８５85% by weight, and 60-15% by weight of inorganic or organic fine powder. If the amount of the fine powder exceeds 60% by weight, it is difficult to form a multilayer resin stretched film having a uniform thickness, and if the amount is less than 15% by weight, the amount of pores formed by stretching is small, so that embossability is poor. turn into.

In the surface layer (B), a thermoplastic resin is used in an amount of 30 to
90% by weight, and 70 to 10% by weight of inorganic or organic fine powder. When the amount of the fine powder exceeds 70% by weight, it is difficult to uniformly stretch the film, and the surface film of the produced multilayer resin stretched film is liable to be cracked, which is not practical. If the amount of the fine powder is less than 10% by weight, ink adhesion will be poor. In the back surface layer (C), 30 to 70% by weight of a thermoplastic resin and 70 to 30% by weight of an inorganic or organic fine powder are blended. If the amount of the fine powder exceeds 70% by weight, it becomes difficult to form a multilayer resin stretched film having a uniform thickness. In particular, the inorganic fine powder subjected to the hydrophilization treatment is preferably used in an amount of 10% by weight or more for exhibiting hydrophilicity.

When the fine powder is mixed and kneaded in the thermoplastic resin, a dispersant, an antioxidant, a compatibilizer, a flame retardant, an ultraviolet stabilizer, a coloring pigment, and the like can be added as required. In particular, it is preferable that the base layer (A) and the surface layer (B) are colored to a desired color by using an inorganic or organic coloring pigment. When the stretched multilayer resin film of the present invention is used as a durable material, it is preferable to add an antioxidant, an ultraviolet stabilizer and the like. Furthermore, when an organic fine powder is used, the type and amount of the compatibilizer are important because they determine the particle form of the organic fine powder. Preferred examples of the compatibilizer include maleic acid-modified polypropylene (trade name: Umex, manufactured by Sanyo Chemical Industries, Ltd.). The amount of the compatibilizer is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the organic fine powder.

The multilayer resin stretched film of the present invention is produced by using a blend containing a thermoplastic resin, fine powder and other additional components. The thickness of each layer of the multilayer stretched resin film to be produced is as follows: surface layer (B) / base layer (A) / backside layer (C) = (1-3) / (8-4) / (1-3) It is preferable to prepare so that By setting the thickness of each layer in this range, a multilayer resin stretched film having excellent surface strength, printability, embossability, and emboss return can be obtained. When the thickness configuration of the base material layer (A) is 4 or less, it is not preferable because embossing is deteriorated.

The stretched multilayer resin film of the present invention can be manufactured by combining various methods known to those skilled in the art. The stretched multilayer resin film produced by any method is included in the scope of the present invention as long as it satisfies the conditions described in claim 1.
Therefore, the base material layer (A), the surface layer (B) and the back surface layer (C) may be manufactured by separately stretching and then laminating, or the base material layer (A), the surface layer ( It may be manufactured by laminating B) and the back layer (C) and then stretching them together. Further, it may be manufactured by laminating the base material layer (A) and the surface layer (B) and then stretching, and then laminating the stretched or unstretched back layer (C). These methods can be appropriately combined.

A preferred production method includes a step of laminating the base material layer (A), the front surface layer (B) and the back surface layer (C) and then stretching them together. Compared to the case of separately stretching and laminating, it is simpler and the cost is lower. Further, the control of the holes formed in the base material layer (A) and the surface layer (B) becomes easier. In particular, the base layer (A) is controlled so that more holes are formed by stretching than the surface layer (B), and the base layer (A) effectively functions as a layer capable of improving the embossability. Is preferred.

For stretching, various known methods can be used. The stretching temperature may be set to be equal to or higher than the glass transition temperature of the thermoplastic resin to be used in the case of the non-crystalline resin, or to be equal to or lower than the melting point of the crystal part in the case of the crystalline resin. it can. The stretching temperature is preferably at least 5 ° C. lower than the melting point of the thermoplastic resin of the surface layer (B), and at least 15 ° C. lower than the melting point of the thermoplastic resin of the base layer (A). Unless the temperature is set in this manner, the sheet is stuck on the roll surface, and the sticking pattern appears on the surface of the multilayer resin stretched film, particularly when performing inter-roll stretching, which is not preferable. Further, the number of cracks formed in the surface layer (B) is reduced, so that the ink adhesion is reduced.

Specific examples of the stretching method include inter-roll stretching using a peripheral speed difference between roll groups, and clip stretching using a tenter oven. Among them, uniaxial roll stretching is preferable because the stretching ratio can be arbitrarily adjusted and the size and number of pores formed can be controlled. In particular, by uniaxially stretching all the layers, holes and cracks are formed in the shape of a football, so that a larger number of fine holes can be formed than in biaxial stretching. In addition, since the resin is stretched and oriented in the flow direction of the film, it is possible to obtain a multilayer resin stretched film having higher tensile strength and less dimensional change due to tension during printing or processing than a non-stretched film.
Furthermore, since the orientation of the resin is less than in biaxial stretching,
A multilayer resin stretched film having good resistance to emboss return can be obtained.

The stretching ratio is not particularly limited, and is appropriately determined in consideration of the intended use of the stretched multilayer resin film of the present invention, the characteristics of the thermoplastic resin used, and the like. For example, when a propylene homopolymer or a copolymer thereof is used as the thermoplastic resin, when it is stretched in one direction, about 1.2 to 12
2 times, preferably 2 to 7 times. Further, heat treatment at a high temperature is performed as necessary. The stretching speed is preferably from 20 to 350 m / min.

The stretched multilayer resin film of the present invention has a porous structure having fine pores, and the porosity calculated by the above formula (1) is in the range of 5 to 60%. If the porosity is less than 5%, embossing will be poor. On the other hand, if the porosity exceeds 60%, the material strength of the film decreases, and the surface is easily broken by cellophane tape or the like. Further, the porosity of each layer must satisfy the relationship of surface layer (B) <base layer (A) <backside layer (C). While not being bound by any theory, by satisfying such porosity conditions, it becomes possible to absorb the thermal deformation of the resin portion that occurs during embossing, and to improve the embossability and return resistance. Is considered to be good. Further, since fine cracks are formed in the surface layer (B), printability is improved.

In formula (1), ρ0 represents the true density of the stretched multilayer resin film or each layer, and ρ1 represents the density of the stretched multilayer resin film or each layer. Unless the material before stretching contains a large amount of air, the true density is approximately equal to the density before stretching. The density of the multilayer resin stretched film of the present invention,
It is preferably in the range of 0.60 to 1.20 g / cm ³ .

The stretched multilayer resin film of the present invention may be used as it is, or may be used after being laminated on another thermoplastic film or the like. When further laminating, it can be laminated on a transparent or opaque film such as a polyester film, a polyamide film and a polyolefin film. The thickness of the stretched multilayer resin film of the present invention is not particularly limited. For example, 30-4
The thickness can be adjusted to 00 μm, preferably 60 to 200 μm. Further, by laminating the film with another film as described above, the overall thickness can be reduced to about 1 mm.

The stretched multilayer resin film of the present invention can be used for various applications. For example, it is useful for wallpaper for architectural decoration, decorative paper for decorative plywood, flooring, interior materials for automobiles, tack labels that have been subjected to adhesive processing, and the like.

The surface layer (B) of the stretched multilayer resin film of the present invention can be printed according to the purpose of use. The type and method of printing are not particularly limited. For example, printing can be performed using a known printing means such as gravure printing using an ink in which a pigment is dispersed in a known vehicle, aqueous flexo, silk screen, UV offset rotary printing, or the like. In addition, printing can be performed by metal deposition, gloss printing, mat printing, or the like. The pattern to be printed can be appropriately selected from natural patterns such as stones, wood, lattices, polka dots, and floral patterns, abstract patterns, characters, and the like.

The multilayer resin stretched film of the present invention can be embossed. Embossing is generally performed after printing, but printing may be further performed after embossing. The embossing can be performed, for example, by using a known various press such as a lithographic press, a roll embossing machine, or an embossing machine to shape the concavo-convex shape of the embossing plate by heat or pressure. The roll embossing method is a method in which the concavo-convex shape of a cylindrical embossing plate is formed on a target material by hot pressing. The hot pressing is performed by heating the resin used for the surface layer (B) of the multilayer resin stretched film between the heat deformation temperature and the melting temperature, and pressing the embossing plate against the surface of the multilayer resin stretched film. After shaping, cooling is performed to fix the shape. As the heating method, for example, a method such as infrared irradiation, hot air blowing, conduction heat from a heating roller, dielectric heating, or the like is used. It should be noted that embossing can be performed simultaneously with film formation before or after stretching without using an embossing machine.

When the stretched multilayer resin film of the present invention is used as a decorative plywood, the design can be improved by wiping after embossing and filling the recess with wiping ink. In particular, it is suitable for reproducing the appearance of the conduit portion of the grain.

It is desirable to form a surface protective layer made of a transparent resin layer on the outermost layer. The surface protective layer has a function of protecting the surface layer and imparting a three-dimensional effect to the design such as a pattern or emboss of the lower layer. Therefore, the surface protective layer is particularly useful when the stretched multilayer resin film of the present invention is used as a decorative board or wallpaper. The surface protective layer can be formed by coating or bonding. In order to further improve the surface physical properties, it is preferable to use a colorless transparent or colored transparent resin having excellent surface physical properties such as weather resistance, abrasion resistance and stain resistance. Preferred as such a resin is
For example, various types of acrylates, polyesters and the like, ionizing radiation curable resins, polyurethanes, two-pack curable resins such as unsaturated polyesters, fluororesins, polysiloxane resins, and the like. The surface protective layer may contain known antibacterial agents, antifungal agents, fragrances and the like.

Other materials can be attached to the back surface of the multilayer resin stretched film which has been subjected to various printing and embossing processes. For example, when used as wallpaper or flooring, backing paper or the like can be attached. The material used for the backing is not particularly limited, for example, thin paper, paper such as kraft paper, inorganic fiber such as glass fiber and carbon fiber, woven fabric, nonwoven fabric, resin film or sheet, metal foil, and simple substance such as woody material. Alternatively, a composite material obtained by laminating the above materials by a known means such as adhesion or heat fusion can be used.

In addition, a laminated resin stretched film of the present invention is laminated on a metal plate such as an iron plate or an aluminum plate using an adhesive or heat fusion to produce a resin decorative plate lined with a plate-like material. Can also. Further, a resin decorative plywood can also be manufactured by laminating the multilayer resin stretched film of the present invention on various types of wood plywood with an adhesive. Furthermore, a tack seal type wallpaper can be manufactured by laminating an adhesive layer or a laminate of the adhesive layer and a release sheet on the backing.

[0044]

The present invention will be described more specifically with reference to the following Examples, Comparative Examples and Test Examples. The materials, usage amounts, ratios, operations, and the like shown below can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. The materials used are summarized in the table below. In addition, MFR in a table | surface means a melt flow rate.

[0045]

[Table 1]

(Examples and Comparative Examples) According to the following procedure, the stretched multilayer resin film of the present invention (Examples 1 to 5)
And a multilayer stretched resin film for comparison (Comparative Examples 1 to 3)
Was manufactured, and wallpaper was manufactured using these. Table 2
Table 1 summarizes the types and amounts of materials used in the production of each film, stretching conditions, and the state of the produced films. Formulations [A], [B] and [C] were prepared by mixing thermoplastic resin, elastomer and fine powder. These compounds were melt-kneaded with three extruders set at 250 ° C., respectively, and the compound [B] was laminated on the front side of the compound [A] and the compound [C] was laminated on the back side in a die. Then, the resultant was extruded and cooled to 70 ° C. by a cooling device to obtain a three-layer unstretched sheet. After heating this sheet to a predetermined temperature, it was stretched at a predetermined ratio between rolls in the longitudinal direction. Next, a corona treatment of 50 W / m ² · min was performed on both surfaces of the obtained stretched film using a discharge treatment machine (manufactured by Kasuga Electric Co., Ltd.) to obtain a multilayer resin stretched film having a three-layer structure. Porosity of each layer of the obtained multilayer resin stretched film,
The overall porosity, thickness and density were as shown in Table 2.

Next, gravure printing of a floral pattern (ink: manufactured by Toyo Ink Co., Ltd., trade name: “CCST”) was applied to the surface layer (B) of the stretched multilayer resin film, and then 100 ° C.
Was embossed with a heated embossing roll. Further, a UV curable resin (manufactured by Dainichi Seika) was applied on the surface so as to be 3 g / m ^2, and a high-pressure mercury lamp (8
(0 W, 10 m / min). Furthermore, 5 g of a water-soluble starch-based paste is applied to the back layer (C) of the multilayer resin stretched film.
/ M ² using a roll coater, and 8
After performing a drying treatment in a dryer set at 0 ° C., a release paper was backed to produce a wallpaper.

[0048]

[Table 2]

(Test Example) The following tests and evaluations were performed on the produced multilayer stretched resin film and wallpaper.

1) Embossability (hanging) The embossing formed on the surface of the wallpaper was visually observed and evaluated according to the following criteria. ：: Three-dimensional effect and sharpness △: Slightly lacking sharpness but three-dimensionality, no problem in practical use ×: Neither depth nor sharpness. Unavailable for practical use

2) Emboss return resistance The backing paper of the wallpaper was removed, and an appropriate amount of water was applied to the starch paste-coated surface with a brush, and the resultant was adhered to the surface of the plywood to prevent air from entering, thereby obtaining a wall plate. Immediately superimpose the two wall plates so that the surfaces on which the wallpapers are stuck are in contact with each other, and place them in a dryer at 60 ° C. for 30 minutes.
A pressurization of 0 kg / m ² was performed for 3 minutes. Thereafter, the wallboard was taken out, and the state change of the emboss was visually observed and evaluated according to the following criteria. ：: No change ：: The three-dimensional effect was slightly reduced, but there was no problem in practical use. Chipping, apparent embossing return, and practical problem x: Emboss is almost completely lost and cannot be used practically

3) Adhesiveness of ink on surface layer (B) Adhesive tape (trade name "Cellotape" manufactured by Nichiban Co., Ltd.) is applied to the surface of the gravure-printed wallpaper and pressed sufficiently. The film was peeled off at a constant speed in a direction at 90 degrees to the adhesive surface. The manner in which ink was removed from the wallpaper surface was visually observed and evaluated according to the following criteria. ：: The ink was not peeled at all. ○: The material portion of the film was destroyed, but there was no problem in practical use. ：: Tape There is resistance at the time of peeling, but most of the ink is peeled off, and there is a problem in practical use.
Unavailable for practical use

4) Surface Strength of Surface Layer (B) An adhesive tape (trade name “Cellotape” manufactured by Nichiban Co., Ltd.) was applied to the surface layer (B) of the multilayer resin stretched film, and pressed sufficiently with a finger. Use a tensile tester (manufactured by Shimadzu Corporation: trade name "Autograph") to apply 100
Peeling was performed at a speed of 0 mm / min. The state change of the surface layer (B) after peeling was observed with the naked eye and evaluated according to the following criteria. 変 化: No change ：: Very slight fluffing of the surface, but no problem in practical use △: Many fluffing of the surface There is a problem in practical use. ×: Peeling occurs from inside the film layer, and it cannot be used practically.

5) Water contact angle of back surface layer (C) The contact angle of the back surface layer (C) of the multilayer resin stretched film was measured using a contact angle meter (made by Kyowa Interface Chemical Co., Ltd .: Model CA- D).

6) Paste Drying Property of Back Layer (C) Starch paste (manufactured by Tokiwa Chemical Co.) is coated on the back layer (C) of the stretched multilayer resin film using a rod bar so that the solid content is 5 g / m ^2. Then, the time required for the coated starch paste to change its surface gloss was measured.

7) Adhesive Adhesion of Backside Layer (C) Adhesive tape (trade name “Cellotape” manufactured by Nichiban Co., Ltd.) is applied to the dried coated surface of the starch paste of 6), and after sufficiently pressing, the adhesive is applied. The tape was peeled off at a constant speed in a direction at 90 degrees to the adhesive surface. The manner in which the glue was removed was visually observed and evaluated according to the following criteria. ：: The adhesive is cohesively broken. ○: The material portion of the film is destroyed. ：: There is resistance when the tape is peeled off, but the glue is partially peeled off from the back layer (C), and there is a practical problem. X: Tape peeling Occasionally there is no resistance and the entire amount of glue peels off from the back layer (C), making it impractical

The results of the above tests are summarized in the following table.

[Table 3]

As is clear from Table 3, the multilayer resin stretched film of the present invention has an embossability, an emboss return resistance, an ink adhesion and a surface strength of the surface layer (B), and a water contact angle of the back layer (C). , Glue drying and glue adhesion are all good (Examples 1 to 5). On the other hand, a film in which the porosity of each layer does not satisfy the relationship of (B) <(A) <(C) or a film in which the total porosity is out of the range of 5 to 60% is obtained. Is inferior and not practical.

[0059]

The multilayer resin stretched film of the present invention is excellent in printing suitability, embossing suitability and backing suitability, and has high surface strength. Therefore, the stretched multilayer resin film of the present invention can be effectively provided for various uses including architectural decoration materials.

Claims (10)

[Claims] The surface of a base layer (A) containing 40 to 85% by weight of a thermoplastic resin and 60 to 15% by weight of an inorganic or organic fine powder is coated with 30 to 90% by weight of a thermoplastic resin and an inorganic or organic fine powder. A surface layer (B) containing 70 to 10% by weight of a powder; and 30 to 70% by weight of a thermoplastic resin and 70 to 3% of inorganic fine powder on the back surface of the base material layer (A).
It has a back layer (C) containing 0% by weight, and the porosity calculated by the formula (1) is as follows: The porosity of the back layer (B) <the base layer (A) Porosity of the surface layer (C) 5% ≦ porosity of the multilayer resin stretched film ≦ 60%. (Equation 1) ρ0: True density of film or layer ρ1: Density of film or layer 2. The multilayer according to claim 1, wherein the average particle size of the inorganic or organic fine powder of the base layer (A) is larger than the average particle size of the inorganic or organic fine powder of the surface layer (B). Stretched resin film. 3. The average particle diameter of the inorganic or organic fine powder of the base layer (A) is in the range of 0.6 to 3 μm, and the average particle diameter of the inorganic or organic fine powder of the surface layer (B) is The multilayer resin stretched film according to claim 1 or 2, wherein the average particle diameter of the inorganic or organic fine powder of the back surface layer (C) is 0.6 to 3 µm. 4. The melting point of the thermoplastic resin of the surface layer (B) is 10 ° C. lower than the melting point of the thermoplastic resin of the base layer (A).
The multilayer resin stretched film according to any one of claims 1 to 3, which is lower than the above. 5. The stretched multilayer resin film according to claim 1, wherein the back layer (C) contains an inorganic fine powder whose surface has been subjected to a hydrophilic treatment. 6. The thermoplastic resin of the base layer (A), the front layer (B) and the back layer (C) is a polyolefin resin, an olefin thermoplastic elastomer, or a polyolefin resin and an olefin heat. The multilayer resin stretched film according to any one of claims 1 to 5, which is a mixture with a plastic elastomer. 7. The composition according to claim 6, wherein the mixture of the polyolefin resin and the olefin thermoplastic elastomer contains 5 to 100 parts by weight of the olefin thermoplastic elastomer based on 100 parts by weight of the polyolefin resin. Multilayer resin stretched film. 8. The contact angle of the back surface layer (C) to water is 1
The stretched multilayer resin film according to any one of claims 1 to 7, which is within a range of 0 to 80 °. 9. The stretched multilayer resin film according to claim 1, wherein the surface layer (B) is embossed. 10. An architectural decorative material using the stretched multilayer resin film according to any one of claims 1 to 9.