JPH07283Y2 - Weatherproof composite sheet with uneven pattern - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a composite sheet having a non-film-like appearance and feel formed from a weather-resistant biaxially stretched polyester-based film having an uneven pattern on its surface. .

[Conventional technology]

Conventionally, a biaxially stretched polyester film (hereinafter abbreviated as a biaxially stretched film), in which a polymer chain is highly oriented and crystallized in a stretching direction to form a dense surface and has many excellent physical properties, is rigid, It lacks in flexibility and exhibits so-called film-like luster and texture.

Further, this biaxially stretched film can be provided with a concavo-convex pattern by performing the above-mentioned embossing or the like in a state where it is heated to a temperature equal to or higher than the softening point of the polymer constituting the film, but in this case, by heat, When the biaxially stretched film is strongly shrunk and its form or its excellent physical properties are impaired, or when the biaxially stretched film is laminated with a substrate or the like,
There was a risk that the biaxially stretched film layer would separate from the base material layer.

JP-B-55-51742 discloses a film product having an uneven pattern on its surface, which is obtained by stretching a film made of a polyolefin resin containing inorganic fine particles and forming a large number of voids inside to make it opaque. A pseudo-skin-like product has been proposed in which it is attached to a synthetic paper sheet-shaped base material, and the surface of the attached body is embossed or rubbed. However, the film layer on the surface of this pseudo-dermis is
Since the film layer is poor in crack resistance and abrasion resistance, the film layer is likely to be cracked or fibrillated to form fluff by the embossing process or the rubbing process, which tends to impair the appearance. Furthermore, since this polyolefin-based film usually has poor weather resistance, the pseudo-skin-like product has a problem in terms of its durability,
It could only be used for limited purposes.

[Problems to be solved by the device]

The object of the present invention is to have a pattern consisting of irregularities of arbitrary shape, size, number, etc., to have a non-film-like appearance and texture, to possess the excellent physical properties of a biaxially stretched film, and to be weather resistant. To provide an excellent composite sheet.

[Means for Solving the Problems]

The composite sheet of the present invention is a weather-resistant biaxially stretched film A,
The stretched void film B and the base material C are laminated and integrated in the order of A / B / C, and an uneven pattern is formed on the surface of the biaxially stretched film A.

The figure is a schematic cross-sectional view showing one embodiment of such a composite sheet of the present invention. As shown in the figure, the composite sheet 1 of the present invention
Comprises a biaxially stretched film A layer 2, a stretched void film B layer 3 and a base material C layer 4, and the biaxially stretched film A layer 2 has an uneven pattern.

The biaxially stretched film A used in the present invention needs to have weather resistance in order to maintain and improve the durability of the composite sheet of the present invention.

The weather-resistant biaxially stretched film A has a refractive index in the orientation degree direction of 1.575 or more, preferably 1.59.
The refractive index in the thickness direction is 1.575 or less, preferably
Those having a density of 1.55 or less and a density of 1.390 g / cm ³ or less, and having a breaking elongation in the orientation direction of the film A of 100% or more even when irradiated with a high-pressure mercury lamp for 100 hours (see, for example, JP-A No. No. 52-4574, biaxially stretched film), various organic compounds having ultraviolet absorbing ability or photostability, such as JP-B-55-10203, JP-B-57-6470 and JP-A-53-101045. Hydroquinone-based, benzotriazole-based, benzophenone-based,
There is a film obtained from a polyethylene terephthalate blended with a phenyl salicylate organic compound, preferably an organic compound represented by the following formula.

(In the above formula, R is an alkyl group having 1 to 12 carbon atoms.) The thickness of the biaxially stretched film A is usually 5 μm to
About 150μ is good.

The concavo-convex pattern of the biaxially stretched film A layer of the composite sheet of the present invention is formed by laminating with the stretched void film B described later, and by laminating the biaxially stretched film A with the stretched void film B. It is possible to prevent the stretched void film B from being deteriorated by heat, light, etc., and prevent the strength from being deteriorated due to cracks or abrasion. That is, in the present invention, it can be said that the biaxially stretched film A layer and the stretched void film B layer are inseparable from each other in compensating for their weak points and utilizing the characteristics of both.

Examples of the stretched void film B include synthetic resin such as polyolefin (polypropylene, ethylene-propylene copolymer, etc.), polyester, polyamide, polyvinyl chloride, etc. and inorganic fine particles (hereinafter referred to as filler).
It is preferable to use a film obtained from a resin containing the above-mentioned compound and having a large number of voids formed therein by stretching.

As the filler, calcium carbonate, magnesium carbonate, alumina, aluminum silicate, kaolin, kaolinite, talc, clay, diatomaceous earth, dolomite, titanium oxide, magnesium oxide, a synthetic resin component forming the film or inorganic particles such as zeolite. Include fine particles made of different synthetic resins, and these fine particles may be a simple substance or a mixture, but preferably calcium carbonate as a main component.

In addition to the filler, a heat stabilizer, an antioxidant,
It goes without saying that various additives such as weathering agents, antistatic agents, nucleating agents and the like can be appropriately added.

The amount of the filler to be blended with respect to the resin is 10 to 40% by weight, preferably 15 to 35% by weight.
If the amount is less than 40% by weight, the stretched void film B has sufficient shrinkability, and the biaxially stretched film A layer has insufficient pattern forming properties, and if it exceeds 40% by weight, the resin composition becomes brittle, At times, tearing easily occurs, making it difficult to form a film.

The stretching may be performed under the condition that voids are formed, and either uniaxial stretching or biaxial stretching may be applied.

The stretched void film B has a content of 30% to 70%, preferably
It is desirable to have a void ratio of 30% to 55%.

Here, the void ratio (%) means that the density of a film having voids is ρ ₀ , the film is thermocompression bonded near the melting point of the synthetic resin of the component, and the density of the film in which the voids are filled is ρ , Is a value defined by the following formula. The density of the film is calculated from the weight and the volume (thickness x area) of the film.

Void rate (%) = [(ρ−ρ ₀ ) / ρ] × 100 If the void rate is too small, the concavo-convex formability decreases, while if it is too large, many void portions are present,
Although it is possible to form a permanent strain irregularity, the film becomes brittle and the strength becomes insufficient.

The void ratio is a value before the unevenness is formed on the composite sheet of the present invention. In order to obtain a film having the above-mentioned predetermined void ratio, the void ratio increases when the film forming conditions of the film, for example, the stretching ratio and the stretching temperature are increased, and the void ratio is increased even if the amount of the filler is increased. You can

The void structure of the stretched void film B does not necessarily have to be uniform in the thickness direction of the film, and for example, the void ratio in the vicinity of the surface may be lower than that in the central portion of the film, or voids may not exist. Rather, the presence of voids on the surface reduces the toughness of the surface, reduces the adhesion to the biaxially stretched film A, and is not preferable in terms of durability such as peeling during or after the formation of irregularities. It is preferable that the surface of the stretched void film B used for the above at least the adhesive surface with the biaxially stretched film A has no voids formed therein.

As a method for producing a stretched void film B having no voids on at least one surface of such a film, two or more kinds of synthetic resins having different addition amounts of filler are coextruded in a film form or synthesized by mixing a filler. Coextruding a resin and a resin that does not contain a filler into a film,
It is then obtained by stretching. In addition, a film is made individually from two or more kinds of synthetic resins having different filler addition amounts or a synthetic resin containing a filler and a resin not containing a filler, and one of these resin film layers is vertically formed. It can be obtained by stretching in the transverse direction, laminating other layers and stretching in the transverse direction.

More specifically exemplifying the production method, a synthetic resin such as polypropylene and the like, which is mixed with a filler such as calcium carbonate, and a synthetic resin such as an ethylene propylene block copolymer which is not mixed with the filler, a filler-containing resin. The thickness ratio of the resin layer containing no filler to the layer is co-extruded at a thickness of about 0.01 to 0.2, stretched in both longitudinal and transverse directions, and stretched at a stretch ratio (length × width) of about 50 to 50 times. Then, heat set.

The stretched void film B thus obtained has a surface wetting tension
It is preferable that the joint surface, that is, the surface of the ethylene propylene block copolymer film layer, is subjected to corona discharge treatment in an atmosphere of air or an inert gas so as to be 40 dyne / cm or more.

Biaxially stretched film A for this stretched void film B
The thickness ratio is 1.0 or less, preferably 0.05 to 0.6,
More preferably, it is 0.1 to 0.3. If this thickness ratio becomes too large, it becomes difficult to form irregularities. If the thickness ratio is within the above range, the thickness of each of the biaxially stretched film A and the stretched void film B is not particularly limited, but the thickness of the biaxially stretched film A is 6 to 50 μm, preferably Is
10-40 μm is preferable, and the thickness of the stretched void film B is 30-
The thickness is 150 μm, preferably 60 to 120 μm.

On the other hand, the base material C layer 4 not only supports the composite film layer, but also by appropriately selecting the type and combining it with the uneven pattern, the flexibility, volume and cushion of the composite sheet of the present invention. And mechanical strength,
In particular, the tear resistance and the like can be improved to further improve the non-film-like appearance or touch. As such a flexible substrate, various knitted fabrics, non-woven fabrics, papers,
For example, foam. These base materials C may be used alone or in combination of two or more depending on the application of the composite sheet, but it is preferable to use a knitted fabric that does not impair the flexibility and drapeability of the composite sheet.

As the adhesive for joining and integrating the films constituting the composite sheet of the present invention and between the composite film and the flexible substrate, a reactive or self-crosslinking polyacrylic ester adhesive Examples thereof include synthetic polymer adhesives such as urethane adhesives and epoxy adhesives, and rubber adhesives.

Further, the composite sheet of the present invention may be subjected to metal vapor deposition, printing or the like at the interface between the biaxially stretched film A and the stretched void film B layer.

As a method of manufacturing the composite sheet of the present invention, a biaxially stretched film A and a stretched void film B are polymerized and bonded in advance to form a composite film, and a flexible substrate is formed on the stretched void film surface of the composite film. Generally, the stretched void film B is joined to a flexible substrate, and the biaxially stretched film A is polymerized on the stretched void film B surface.
It can also be joined.

The biaxially stretched film A surface of the composite sheet thus obtained is subjected to embossing using an embossing roll or an embossing plate, mechanical rubbing, wrinkling with a tumbler, creping with crepe paper, pleating, etc. It is applied in combination to give an uneven pattern.

In order to prevent the heat shrinkage of the biaxially stretched film A layer constituting the composite sheet and the deterioration of the physical properties due to the shrinkage, the biaxially stretched film A is not thermally affected but the stretched void film B layer shrinks under temperature conditions. At the same time as imparting mechanical unevenness, the stretched void film B layer can be thermally shrunk. Further, by heat-treating under such conditions, a concavo-convex pattern (wrinkles) resulting from the heat shrinkage of the stretched void film B can be formed on the biaxially stretched film A surface.

The thus-obtained composite sheet of the present invention having an uneven pattern can form an uneven pattern on the surface of the biaxially stretched film A by a simple operation such as hand rubbing. The concavo-convex pattern of can be changed by the user himself.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example Melt index (MI) based on ASTM-D1238 is 1.0
A polypropylene resin having a particle size of 1.7μ and 20% by weight of calcium carbonate was melt-cast by a known method, and biaxially stretched 3.5 times in the vertical direction and 9 times in the horizontal direction. By heat setting, a stretched void film having a thickness of about 60μ was prepared.

On the other hand, to dry polyethylene terephthalate with an [η] of 0.60 (measured at 35 ° C with orthochlorophenol as the solvent) 0.5% by weight of an organic compound represented by was melted at 280 ° C., extruded on a casting drum kept at 40 ° C., rapidly cooled and solidified to prepare an unstretched film. This unstretched film is stretched 3.1 times at a longitudinal stretching temperature of 60 ° C and a transverse stretching temperature of 60
Sequentially stretched 3.4 times at ℃, heat set at 125 ℃ for 15 seconds, thickness
A biaxially stretched film having 100 μ, a density of 1.3750, a breaking strength in the longitudinal direction of 28.5 kg / mm ² , and a breaking elongation of 28.0% was obtained. The biaxially stretched film and the stretched void film are used as a urethane adhesive "SEICA BOND" E260 / manufactured by Dainichiseika Kogyo Co., Ltd.
C26) was used for bonding and lamination to obtain a composite film.

Next, a 50/50 mixed-spun plain fabric of polyester fiber and rayon was bonded to the stretched void film surface of this composite film using the above urethane adhesive.

The obtained composite sheet was embossed at 60 ° C. to form an uneven pattern on the surface of the biaxially stretched film.

On the surface of the resulting composite sheet having an uneven pattern, a high-pressure mercury lamp (H400P type mercury lamp for photochemistry manufactured by Toshiba Corporation)
(Using a 100V power source), the biaxially stretched film layer of the composite sheet is placed in parallel at a position 20 cm away from the rod-shaped radiation source,
The light with the strongest vector of 365 nm was irradiated for 200 hours. The breaking strength before and after irradiation was measured, and the presence or absence of a decrease in strength was examined. As a result, no substantial decrease was observed.

[Effect of device]

The surface of the composite sheet of the present invention has many excellent physical properties, and has a transparent and weather resistant biaxially stretched film A layer made of polyethylene terephthalate, and the biaxially stretched film A layer has an uneven pattern. In spite of the fact that it has the above, it is not substantially affected by the heat at the time of forming this uneven pattern, and therefore it retains the above excellent film characteristics.

And, due to the excellent transparency of the biaxially stretched film A layer,
The metal vapor deposition, printing, etc. described above, which is applied in combination with the uneven pattern, is clear and has excellent durability, and the appearance, gloss and feel of the surface of the composite sheet of the present invention are more complicated, beautiful and precise. And, it can be soft and warm with excellent decoration.

Moreover, since the composite sheet of the present invention can easily form a wrinkle-like concavo-convex pattern by a simple operation, for example, the most simple rubbing by hand, an artificial rubbing treatment can be performed before or after commercialization. It is possible to give wrinkles having different shapes, numbers, sizes, depths, etc. by applying them to change the appearance and gloss of each product, that is, individualize.

Therefore, the composite sheet of the present invention, by itself or in combination with existing materials, can be used as a wall material, floor material, covering material,
In addition to applications as furniture and interior materials for automobiles, it can be applied to fields such as outdoor applications that were previously unusable as films.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of the composite sheet of the present invention. 1 ... Composite sheet, 2 ... Biaxially stretched polyester film A
Layer, 3 ... Stretched void film B layer, 4 ... Substrate C layer.

Claims (1)

[Scope of utility model registration request] 1. A weather-resistant biaxially stretched polyester-based film A, a stretched void film B and a substrate C are laminated and integrated in the order of A / B / C, and the surface of the biaxially stretched polyester-based film A is uneven. A weather-resistant composite sheet having an uneven pattern formed by a pattern.