JPH0647788B2 - Tile carpet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a tile carpet, and more specifically, the present invention is excellent in aesthetics and foot feeling,
The present invention relates to an improved tile carpet which has good workability, softness, flexibility and fit to a floor surface, and has no fear of delamination in a backing and which can be used by simple laying.

[Conventional technology]

Conventionally, a plastic material tile called a so-called vinyl tile has been used as a floor covering material for offices and houses. This vinyl tile was hard, cold, had a bad foot feeling, and was easily tired, and had a poor aesthetic appearance. For this reason, instead of vinyl tiles, long carpets having an upper surface layer formed of a fiber material have been used. However, such a long carpet is troublesome to carry, carry in, and construct, and when it is locally soiled, it cannot be locally replaced, and local repair causes a problem that the appearance is significantly impaired. There is a point.

In recent years, tile carpets of various shapes, for example, squares, rectangles, and rhombuses have come to be used as bedding materials for solving the above problems. Such a tile carpet is easy to carry, carry in, and construct,
It has the advantages that it can be replaced locally and that a desired pattern can be formed by combining tile carpets of various colors. Such a conventional tile carpet is composed of an upper surface layer made of a fiber material and a backing layer provided on the back surface thereof, and the backing layer is made of a thermoplastic material such as bitumen or atactic polypropylene at room temperature. It consists of a layer of adhesive material that is likely to be permanently deformed and a back surface layer of paper or the like that is attached to the back surface of the adhesive material. It adhered to the floor surface to give the tile carpet a fit to the floor surface,
This causes contamination of the floor surface, and the effect of the tile carpet as a simple replacement carpet has not been fully utilized.

Recently, a backing layer formed of a polyvinyl chloride resin has also appeared, and its demand is increased due to its excellent fit to a floor surface and ease of use.

As described above, the conventional tile carpet generally expects an adhesive fit to the floor surface, but if the adhesive layer is not used and therefore it can be used simply by laying it without contamination of the floor surface, the demand will be high. It is expected to grow even larger.

In order to use the tile carpet without the above-mentioned drawbacks, the tile carpet can be fixed simply by placing it on the floor surface without slipping, and by a light shock such as a kick foot or a trip. It is necessary that the carpet does not slip on the floor. For such a purpose, it is effective to increase the weight of the backing layer of the tile carpet, and for this reason, a large amount of inorganic filler is mixed in the backing layer. However, in the conventional tile carpet, the adhesiveness between the backing layer and the upper surface layer formed of the material, or the adhesiveness tends to be lowered by the use of a large amount of the inorganic filler, and therefore, the upper surface layer. There is a problem that the pile is easily pulled out.

In order to solve the above problems, a base material made of a thermoplastic polymer material or a rubber material on the back surface side of the upper surface layer formed of a fiber material, and 300% or less by weight of the inorganic filler, A tile carpet formed with one polymer layer, a base material made of a thermoplastic polymer material or a rubber material, and a second polymer layer containing 250% or more by weight of the inorganic filler, and the first carpet. Proposed is a tile carpet in which a fiber cloth intermediate layer is provided between a polymer layer and a second polymer layer, and / or a fiber cloth back surface layer is provided under the back surface of the second polymer layer (Japanese Patent Laid-Open No. Sho-62-62). 61-119780, and JP-A-61-275484
issue).

However, after that, it has been considered that it is necessary to prevent delamination between the first polymer layer and the second polymer layer, and further improve the fitting property to the floor surface. It was

[Problems to be Solved by the Invention]

In a tile carpet having a fiber upper surface layer and a backing layer, the present invention maintains good aesthetics, a feeling of footsteps, workability, softness and flexibility, and fitability to a floor surface while at the same time performing delamination of the backing layer. The present invention aims to provide a tile carpet that is preventable and can be simply placed and used.

[Means for Solving the Problem and Its Action] The tile carpet of the present invention comprises: an upper surface layer formed of a fiber material; a base material made of a flexible polymer material;
A first polymer layer comprising an inorganic filler of about 300% by weight and formed under the upper surface layer, a base material made of a flexible polymer material, and its weight relative to the first polymer layer. 300
% Of an inorganic filler, and a second polymer layer formed under the first polymer layer, wherein the first polymer layer and the second polymer layer A third polymer layer containing a base material made of a flexible polymer material and 0 to 50% by weight of the inorganic filler is formed between the second polymer layer and the second polymer layer. It is a feature.

The tile carpet of the present invention also includes the third polymer layer and the second polymer layer between the first polymer layer and the third polymer layer.
At least one fiber material is provided between the polymer layer and at least one location selected from the back of the second polymer layer.
The fabric layer of the layer may be formed. The fabric layer disposed adjacent to the third polymer layer as described above will be referred to as a fabric intermediate layer, and the fabric layer disposed on the back side of the second polymer layer will be referred to as a fabric back layer. As will be apparent from the above, the fabric intermediate layer may be disposed on either side of the third polymer layer, or on both sides thereof.

Hereinafter, the tile carpet of the present invention will be described in more detail with reference to the accompanying drawings.

The tile carpet shown in FIG. 1 is laminated in order from the top and is bound to each other. The upper surface layer 1, the first polymer layer 2, the third polymer layer 6 and the second polymer layer 3 are laminated. It consists of The first, third and second polymer layers 2, 6, 3 integrally form a backing layer 7.

In the tile carpet shown in FIG. 2, the first
The fabric intermediate layer 4 is formed between the polymer layer 2 and the third polymer layer 6, and the first, second, and third polymer layers 2, 3, 6
The backing layer 7a is formed by the cloth intermediate layer 4 and the cloth intermediate layer 4.

In the tile carpet shown in FIG. 3, the cloth back surface layer 5 is formed on the back surface of the second polymer layer 3, and the first, second and third polymer layers 2, 3, 6 and the cloth back surface are formed. Layer 5
Form a backing layer 7b.

In the tile carpet shown in FIG. 4, the cloth intermediate layer 4 is formed between the third polymer layer 6 and the second polymer layer 3, and the cloth back surface layer 5 is formed on the back surface of the second polymer layer 3. The backing layer 7c is formed by the first, second, and third polymer layers 2, 3, and 6, the cloth intermediate layer 4, and the cloth back surface layer 5.
Are formed.

As mentioned above, the fabric layer is the first, third polymer layer, the third, second polymer layer.
It is provided in one or more places between the polymer layers and the back of the second polymer layer. The fabric layer is composed of one or more fiber fabrics.

In the tile carpet of the present invention shown in FIG. 2, the fabric intermediate layer 4 includes the second polymer layer 3 and the third polymer layer 6.
May be disposed between the two layers, or two fabric intermediate layers may be disposed on both upper and lower sides of the third polymer layer 6.

Further, in the tile carpet of the present invention shown in FIG. 4, the fabric intermediate layer 4 may be disposed between the first polymer layer 2 and the third polymer layer 6, or Two cloth intermediate layers may be arranged on both upper and lower sides of the third polymer layer 6.

The upper surface layer 1 is made of a fibrous material, and there is no particular limitation on the configuration or shape thereof, and it may be any of woven fabric, knitted fabric, non-woven fabric, a composite of these, or a napped fabric.
However, napped fabrics having a pile layer are generally preferred. In the embodiment shown in FIGS. 1 to 4, the upper surface layer 1
Is formed of a napped fabric composed of an upper surface base cloth layer 1b and a pile layer 1a extending from the upper surface base cloth layer 1b.

There is no particular limitation on the type of fiber forming the upper surface layer 1,
One or more of natural fibers such as cotton, hemp, and wool, synthetic fibers formed from synthetic polymers such as polyester, polyethylene, polypropylene, nylon 6, nylon 66, acrylic polymers, and semi-synthetic fibers such as cellulose acetate May be used, and further, glass fibers, carbon fibers or metal fibers may be mixed. These fibers are cotton-like or yarns (spun or multifilament yarns), tape yarns, split yarns or
It may be used in any shape such as a monofilament having a circular or irregular cross section or a flat monofilament. The napped cloth used for the upper surface layer 1 may be any known napped cloth such as cut pile cloth, loop pile cloth, needle punch, napped cloth, and tufted napped cloth. The upper surface layer 1 may contain a conductive material such as carbon fiber or metal fiber.

First polymer layer 2, second polymer layer 3 and third polymer layer 6
Is formed of a flexible polymer material as a base material. Such polymer materials include polyvinyl chloride resin (PVC), polyurethane resin, ethylene-vinyl acetate copolymer resin, isotactic polypropylene resin, vinyl chloride-vinyl acetate copolymer resin, natural rubber, and synthetic rubber. It is preferable to use one or more selected from the group such as SBR and chlorosulfonated polyethylene rubber. The most preferred polymeric material is PVC, which may contain plasticizers, fillers, colorants, stabilizers and / or other modifiers. The base material may contain a filler such as atactic polypropylene and / or bitumen.

The first polymer layer 2 contains 100 to 300%, preferably 100 to 200%, of the inorganic filler by weight of the base material, and the second polymer layer 3
Is 300% or more, preferably 350% to 70% by weight of the base material.
It contains 0%, more preferably 400 to 600% inorganic filler. The third polymer layer 6 has a base material weight of 0.
It is preferable that the content of the inorganic filler is ˜50%, and the content of the inorganic filler is zero. The third polymer layer 6 can firmly adhere the first and second polymer layers 2 and 3 and prevent delamination between them. Also, the third polymer layer 6
Is flexible because the content of the inorganic filler is a small amount of 50% or less based on the weight of the base material. Therefore, the tile carpet obtained has good elasticity and flexibility, and gives a feeling of stepping. It has the effects of improving the pressure, facilitating bending, and buffering the compression impact.

The first polymer layer 2 and the second polymer layer 3 each independently have a weight within the range of 1000 to 3000 g / m ² , independently of each other, and
Preferably it has a thickness in the range of 5 to 3 mm, the third
The polymer layer 6 preferably has a weight in the range of 100 to 2000 g / m ²² .

The third polymer layer 6 may be colored differently from the first and second polymer layers 2 and 3. This coloring is effective in terms of manufacturing process control, aesthetics, quality control, and the like.

There is no particular limitation on the inorganic filler used for the first, second and third polymer layers 2, 3 and 6, and any inorganic filler can be used as long as it is conventionally used for a backing layer of a tile carpet. It may be wood. Generally, as inorganic fillers, mica, calcium silicate, magnesium carbonate, iron oxide, white carbon, silica stone, magnesium hydroxide, aluminum hydroxide, zinc oxide, basic magnesium carbonate, asbestos, zeolite, white sinter, molybdenum, titanium oxide. , Sericite, shirasu, graphite, calcium hydroxide, calcium sulfite, gypsum and fiber, synthetic silicic acid fiber (processed mineral fiber: PM
F), quartz powder, bentonite, metal whiskers, sodium sulfate, calcium carbonate, aluminum silicate, clay,
Talc, silica (silica dioxide), diatomaceous earth, silica sand,
Pumice powder, slate powder, mica powder, alumina, alumina white, aluminum sulfate, barium sulfate, lithopone, calcium sulfate, molybdenum disulfide, graphite, glass powder, beads, hollow spheres and fibers, and carbon (black) powder and At least one selected from fibers and the like can be used.

The fiber cloth used for forming the cloth intermediate layer and the cloth back surface in the tile carpet of the present invention is effective in imparting appropriate deformation resistance and hardness to the tile carpet and enhancing its workability. These base fabrics can be woven, knitted and non-woven fabrics, and composites thereof, but coarse woven or knitted fabrics or non-woven fabrics are most preferred. The type of fiber forming these cloths is not particularly limited, and may be any of glass fiber, polyester fiber, polyamide fiber, polypropylene fiber, rayon fiber and the like, but glass fiber and polyester fiber are preferable. The fabric weight of the fabric intermediate layer and the fabric back surface layer, and the thickness is not particularly limited, but generally, the fabric weight of the fabric intermediate layer is 10 to 200 g / m ² ,
Is preferable, and more preferably 50 to 150 g / m ² . The fabric weight of the fabric backside layer is 10
Is preferably to 100 g / m ^2, and still more preferably from 20 to 70 g / m ^2.

The fabric having the above basis weight is impregnated with a part of the polymer material forming the polymer layer to have appropriate hardness and rigidity. Further, in general, the fabric forming the back surface layer of the fabric has a relatively small basis weight (g / m ² ), so that a part of the polymer material forming the second polymer layer 3 penetrates into the back surface layer of the fabric. It is preferable that it is easy and can provide appropriate hardness and rigidity. In some cases, a portion of the polymeric material may exude to the backside to form a thin polymeric layer.

Furthermore, in the cloth intermediate layer arranged in the middle of the backing layer,
A polymer material having the same composition as the third polymer layer may be impregnated.

That is, as described above, each polymer layer and each fabric layer are not simply attached to each other, but a part of the polymer material forming the polymer layer penetrates into the fabric layer. It is preferable that the coalescence layer is firmly bound.

In order for the tile carpet to fit the floor surface, it must have a suitable weight. For this, it is preferred that the total weight of the backing layer is in the range of 2.0~6.0kg / m ^2, and still more preferably in the range of 3.0~5.0kg / m ^2. When the total amount of these is less than 2.0 kg / m ² , the tile carpet obtained even when the third polymer layer is formed has poor fit to the floor surface, and when the total amount is more than 6.0 kg / m ² , construction is difficult. Tend to be difficult and economically disadvantageous.

In order to produce the tile carpet of the present invention, a release agent is applied, and the cloth for forming the cloth back surface layer is placed on the wire mesh base heated to a predetermined temperature (150 to 200 ° C.), or A polymer material for directly forming the second polymer layer without placing a cloth, for example, a paste composed of polyvinyl chloride, DOP (plasticizer), an inorganic filler, a pigment, and a stabilizer, for example, a fabric weight 13
Apply so that it becomes 00g / m ² .

A fabric for forming a fabric intermediate layer on the second polymer layer,
For example, a non-woven fabric having a basis weight of 80 g / m ^{2 made} of polyester fiber is laminated, or a material (paste) for directly forming the third polymer layer is formed without forming such a cloth intermediate layer,
For example, it is applied so that the basis weight is 500 g / m ² . Then, a polymer material for forming a first polymer layer is further laminated thereon, or a fabric for an intermediate layer is further laminated directly or without such a fabric, for example, polyvinyl chloride, a plasticizer, Inorganic filler,
A paste containing a stabilizer or the like is applied so as to have a basis weight of 200 g / m ² .

An example of the composition of the composition for forming the first, second and third polymer layers is shown below.

Next, on the first polymer layer, a fibrous material for forming the upper surface layer, for example, a polyester fiber non-woven fabric having a basis weight of 120 g / m ² is used as a base fabric, and a 100% nylon multifilament yarn is tufted on the base fabric. And the cut pile fabric having a basis weight of about 1.5 kg / m ² is laminated. At this time, it is preferable that a part of the polymer paste forming the first polymer layer penetrates into the cloth forming the upper surface layer to enhance mutual adhesive strength. Further, it is preferable that the polymer of the polymer layer in contact with the cloth forming the cloth intermediate layer and the cloth back surface layer also permeate, thereby strengthening the mutual adhesion. The thus obtained laminate is subjected to a solidification step of the polymer material, for example, for polyvinyl chloride, a gelation step at 180 ° C. for a desired time, for example 10 minutes. Thereby, the laminated layers are bound to each other.

When forming the cloth back surface layer, a cloth for the cloth back surface layer, for example, a non-woven fabric made of polyester fiber having a basis weight of 80 g / m ² is placed on the wire netting base, and the above operation may be performed thereon. When the polymer is permeated and exuded on the back surface of the fabric back surface layer, or when the polymer is applied thinly on the back surface, it may be embossed in a desired pattern. Next, the obtained laminate is cut into a square having a desired shape and size, for example, 50 cm × 50 cm to obtain a tile carpet.

When the fiber material forming the upper surface layer is a napped cloth, in order to prevent the napped fibers from falling off, the
You may perform an adhesive treatment for adhesion with a base cloth.

There is no particular limitation on the type of adhesive as long as it is effective for its intended use. Generally, an ethylene-vinyl acetate copolymer and / or an adhesive mainly composed of polyvinyl chloride is used. It is desirable that the amount of adhesive used is as low as possible, generally 300-1300 g / m ² , 500-1000
It is preferably g / m ² . The applied adhesive may be evenly distributed on the back surface of the pile cloth, or may be unevenly distributed according to the structure of the pile cloth. Further, the adhesive may be applied discontinuously only to the root portion of the pile. Furthermore, the adhesive layer may be foamed, which has the effect of reducing the applied weight of the adhesive layer.

In the tile carpet of the present invention, a conductive fiber is mixed in the upper surface layer, or a conductive substance is mixed in the first, second and third polymer layers, thereby preventing the carpet from being charged, and If appropriate conditions are selected, it is possible to positively make the carpet conductive.

〔Example〕

 The invention is further described by the following examples.

[Example 1 and Comparative Example 1] A tile carpet having layers laminated in the order described in Table 1 from above was produced by the above-described production method. The performance of the resulting carpet is shown in Table 2.

The performance of the obtained tile carpet was as shown in Table 2.

[Example 2] The same operation as in Example 1 was carried out to produce a tile carpet, but without using a fabric layer. The performance of the obtained tile carpet was as shown in Table 3.

Example 3 A liquid having the following composition was applied to a fabric in which a glass mesh fabric (60 g / m ² ) was superposed on a polyester nonwoven fabric (50 g / m ² ).

Composition PVC 100 (parts by weight) DOP 90 CaCO ₃ 0 Pigment (green) 5 Triclen (solvent) 10 Dry this coating liquid layer at 120 ° C, and deposit 300 g / m ² ,
A layered product was prepared which was composed of a third polymer layer in which PVC was not gelled and a first fabric intermediate layer made of a fiber fabric.

Next, according to the original procedure, with the same configuration as in Example 1, the release agent was applied, and the cloth for forming the back surface layer of the cloth (glass mesh cloth, on the wire mesh base heated to a predetermined temperature (200 ° C.), 60 g / m ² ), and the following polymer material for forming the second polymer layer, composition PVC 100 (parts by weight) DOP 90 CaCO ₃ 450 pigment (black) 5 trichlene (solvent) 10 It was applied so as to be m ² .

On the second polymer layer, a fabric forming the second fabric intermediate layer (the same as the fabric for the first fabric intermediate layer) and a material forming the third polymer layer are applied and not yet gelled. A polymer material for forming the first polymer layer on top of the above-prepared laminated materials, PVC 100 (part by weight) DOP 90 CaCO ₃ 200 Pigment (black) 5 Triclen ( Solvent) 10 was applied to have a basis weight of 1800 g / m ² .

Next, as a fibrous material for forming the upper surface layer on the first polymer layer, a polyester fiber nonwoven fabric having a basis weight of 120 g / m ² is used as a base fabric, and a multifilament yarn of 100% nylon is tufted on the base fabric. Approximately 1.
A 5 kg / m ² cut pile fabric was laminated. At this time, a part of the polymer paste forming the first polymer layer penetrated into the cloth forming the upper surface layer to enhance mutual adhesive strength. Further, the polymer of the polymer layer in contact therewith also penetrates into the fabric forming the intermediate fabric layer and the back fabric layer,
As a result, mutual adhesion was strengthened. The thus obtained laminate was subjected to a solidifying step of the polymer material, that is, a gel step at 180 ° C. for 10 minutes. Thereby, the laminated layers were bound to each other.

Next, the obtained laminated body is formed into a desired shape and dimensions (50 cm × 50
cm square) to obtain a tile carpet.

The performance of the tile carpet thus obtained was almost the same as the result of Example 1 and was preferable.

〔The invention's effect〕

The tile carpet of the present invention has less pile pull-out due to friction of the upper and lower layers, has a good feeling of stepping, low fatigue, placement stability, dimensional stability and resistance to deformation, is flexible and has excellent flexibility. It has a good fit and is easy to apply. Moreover, there is no delamination or floating phenomenon of the packing layer and it is extremely good in practical use.

[Brief description of drawings]

1, 2, 3 and 4 are cross-sectional explanatory views showing the configuration of an embodiment of the tile carpet of the present invention. 1 ... upper surface layer, 1a ... pile layer, 1b ... base cloth layer, 2
... first polymer layer, 3 ... second polymer layer, 4 ... fabric intermediate layer, 5 ... fabric back layer, 6 ... third polymer layer, 7,7a, 7b, 7c ... backing layer.

Claims (17)

[Claims] 1. An upper surface layer formed of a fibrous material, a base material made of a flexible polymer material, and 100 based on the weight thereof.
A first polymer layer comprising an inorganic filler of about 300% by weight and formed under the back surface of the upper surface layer, a base material made of a flexible polymer material, and its weight. For 300
% Of an inorganic filler, and a second polymer layer formed on the back surface side of the first polymer layer, and the first polymer layer and the second polymer layer. A third polymer layer containing a base material made of a flexible polymer material and an inorganic filler of 0 to 50% based on the weight of the base material is formed between the third polymer layer and the polymer layer. And tile carpet. 2. The flexible polymer material contained in the first, second, and third polymer layers is a polyvinyl chloride resin, a polyurethane resin, an ethylene-vinyl acetate copolymer, which is independent for each layer. The tile carpet according to claim 1, which contains at least one selected from a resin, a vinyl chloride-vinyl acetate copolymer resin, a polypropylene resin, natural rubber, SBR, and chlorosulfonated polyethylene rubber as a main component. . 3. The inorganic filler contained in each of the first, second and third polymer layers comprises, for each layer, mica, calcium silicate, magnesium carbonate, iron oxide, white carbon, silica stone independently of each other. Magnesium hydroxide, aluminum hydroxide, zinc oxide, basic magnesium carbonate, asbestos, theolite, white barley, molybdenum, titanium oxide, sericite, shirasu, graphite, calcium hydroxide, calcium sulfite, gypsum and fiber, synthetic silicate fiber (Processed mineral fiber: PMF), quartz powder, bentonite, metal whiskers, sodium sulfate, calcium carbonate, aluminum silicate, clay, talc, silica (silicon dioxide), diatomaceous earth, silica sand, pumice powder, slate powder , Mica powder, alumina, alumina white, aluminum sulfate, barium sulfate, lithium Pont, calcium sulfate, molybdenum disulfide, graphite, glass powder, beads,
The tile carpet according to claim 1, comprising at least one selected from hollow spheres and fibers, carbon (black) powder and fibers, and the like. 4. The tile according to claim 1, wherein the content of the inorganic filler in the first polymer layer is in the range of 100 to 200% based on the weight of the flexible polymer material. carpet. 5. The weight of the first polymer layer is 800 to 3000 g / m ^2.
The tile carpet according to claim 1, wherein the tile carpet is within the range. 6. The tile carpet according to claim 1, wherein the content of the inorganic filler in the second polymer layer is in the range of 350 to 700% based on the weight of the flexible polymer material. . 7. The weight of the second polymer layer is 800 to 3000 g / m 2.
The tile carpet according to claim 1, which is in the range of ² . 8. The tile carpet according to claim 1, wherein the content of the inorganic filler in the third polymer layer is zero. 9. The weight of the third polymer layer is 100 to 2000 g / m ^2.
The tile carpet according to claim 1, wherein the tile carpet is within the range. 10. A tile carpet according to claim 1, wherein the total weight of said first, second and third polymer layers is in the range 2000-6000 g / m ² . 11. The tile carpet of claim 1, wherein the third polymer layer has a different color than the first and second polymers. 12. The tile carpet according to claim 1, wherein the back surface of the upper surface layer is treated with an adhesive. 13. An upper surface layer formed of a fibrous material, a base material made of a flexible polymer material, and 100 based on the weight thereof.
A first polymer layer comprising an inorganic filler of about 300% by weight and formed under the back surface of the upper surface layer, a base material made of a flexible polymer material, and its weight. For 300
% Of an inorganic filler, and a second polymer layer formed on the back surface side of the first polymer layer, and the first polymer layer and the second polymer layer. A third polymer layer is formed between the polymer layer and a base material made of a flexible polymer material, and an inorganic filler of 0 to 50% based on the weight thereof, and Between the first polymer layer and the third polymer layer, between the third polymer layer and the second polymer layer, and at least one location selected from the back of the second polymer layer, A tile carpet, wherein at least one fabric layer made of a fiber material is formed. 14. The tile carpet according to claim 13, wherein the weight of the fabric layer is in the range of 10 to 200 g / m ² . 15. The first, second and third polymer layers,
The tile carpet according to claim 13, wherein the total weight of the tile carpet and the fabric layer is in the range of 2000 to 6000 g / m ² . 16. Formed in at least one location selected from between the first polymer layer and the third polymer layer and between the third polymer layer and the second polymer layer. 14. The tile carpet according to claim 13, wherein the existing fabric layer is impregnated with a polymer material having the same composition as the third polymer. 17. The tile carpet according to claim 13, wherein the back surface of the upper surface layer is treated with an adhesive.