JPH0362549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an acrylic resin laminate having excellent bending resistance. More specifically, the present invention provides a specially structured woven base fabric, a soft polyvinyl chloride layer, and an acrylic resin layer, which have excellent bending resistance, flexibility, weather resistance, and antifouling properties, especially resistance to cold bending and flex cracking. The present invention relates to a laminate comprising:

Technical background Conventionally, flexible laminated sheets made of a fiber base fabric, especially a plain weave base fabric, coated with a soft polyvinyl chloride resin (hereinafter referred to as PVC) layer on one or both sides, have been used for large tents such as air domes. There is. This product exhibits the essential advantages of PVC in terms of workability, economy, flame resistance, etc. However, these types of tents are exposed outdoors for long periods of time, and even if the stabilizers contained in the PVC layer were carefully examined, they gradually deteriorate over the years.
This causes decomposition of the PVC resin, and the plasticizer migrates to the surface, making the surface gradually sticky.
It had serious drawbacks such as dust and the like adhering to its surface, making it difficult to remove.

As a countermeasure to the above-mentioned drawbacks of conventional laminated sheets, considerable effects have been achieved by forming an acrylic resin film layer on the PVC layer. However, such laminates, if rubbed too hard during their use, will cause cracks in the acrylic resin film layer, which, if further enlarged, will also cause cracks in the underlying PVC layer, and this phenomenon is especially noticeable in cold temperatures. This is sometimes noticeable, and therefore has the drawback of significantly shortening the service life of the laminate.

The present invention was made in view of the above circumstances and to eliminate the drawbacks of conventional laminated sheets. When we examined measures to prevent cracks in this surface layer by dispersing stress, we found that knitted fabrics with a large degree of expansion and contraction under load are unsuitable for such applications due to the required performance, and knitted fabrics with a small degree of expansion and contraction under load are unsuitable. Although a plain woven fabric is advantageous, it has been discovered that when such a woven fabric is made into a laminate as described above, the stress applied to the acrylic layer becomes large, making cracks caused by the base fabric more likely to occur. The present invention has been completed by solving these inconveniences. .

OBJECTS OF THE INVENTION An object of the present invention is to provide an acrylic resin laminate that has excellent bending resistance, particularly in cold weather, and also has excellent flexibility, weather resistance, and stain resistance.

Summary of the Invention The present invention provides a warp layer consisting of a large number of warp threads arranged parallel to each other, and a warp layer that is perpendicular to the warp threads.
A special structure woven fabric base fabric comprising a weft layer consisting of a large number of weft yarns arranged parallel to each other, and a leno yarn that entangles and connects the warp yarns and weft yarns at their intersections; , and includes an intermediate layer made of a soft polyvinyl chloride resin, and a surface layer formed on the intermediate layer and made of an acrylic resin, and the thickness of the surface layer is 10 to 10.
50 microns, and a large number of convex portions and concave portions are formed on the surface of the surface layer, and the height difference between the highest point of each convex portion and the lowest point of each concave portion adjacent to it is To provide an acrylic resin laminate characterized by having a thickness of 5 microns or more.

DETAILED DESCRIPTION OF THE INVENTION The laminate of the present invention comprises a specially structured woven fabric, an intermediate layer made of a soft polyvinyl chloride resin formed on at least one surface thereof, and an acrylic resin formed on the intermediate layer. and a surface layer.

The special structure woven base fabric used in the laminate of the present invention includes natural fibers such as cotton and linen, inorganic fibers such as glass fiber, recycled fibers such as viscose rayon and Kyupra, semi-synthetic fibers, selected from, for example, di- and tri-acetate fibers, and synthetic fibers such as nylon 6, nylon 66, polyester (such as polyethylene terephthalate) fibers, aromatic polyamide fibers, acrylic fibers, polyvinyl chloride fibers, and polyolefin fibers. It consists of at least one species. The fibers in the base fabric may be in any form such as short fiber spun yarn, long fiber yarn, split yarn, or tape yarn. These are arranged in parallel to each other, and the warp and weft layers thus formed are laminated so as to intersect with each other, and are loosely connected by long leno threads at the intersections of the warp and weft threads.

The leno thread is made of polyester, nylon, aromatic polyamide and other known synthetic fibers, glass fiber,
It may be selected from steel fibers and other known inorganic fibers, but polyester filament yarn is particularly suitable.

Now, for example, as warp and warp yarns, we are using tensile strength single yarns.
When 1.3Kg of Vinylon 10S/1 spun yarn is used, the tensile strength per unit denier is as a leno yarn.
20 g of aromatic polyamide filament yarn is used, and if yarns of the same material are used in consideration of ease of sheet processing, for example, polyester filament yarn with a tensile strength of 8 g per unit denier is used as the warp yarn. 10 g of polyester filament yarn is used as the yarn and leno thread.

A particularly preferable structure of the special structure fabric for use in the present invention is disclosed in Japanese Patent Publication No. 57-1979 filed by the present applicant.
30381, a warp layer consisting of a large number of warps arranged in parallel to each other, a weft layer consisting of a large number of wefts arranged in parallel to each other so as to be orthogonal to the warps, and the warp and weft It consists of a tangle of threads that are entangled and connected at their intersections. The leno thread is longer than the warp and weft threads, and therefore,
The warp and weft are loosely connected, and at least one of the tensile strength, tensile elongation, and breaking work is greater than that of the warp and weft, and/or the adhesive strength to the resin material is It is preferable that the diameter is smaller than that of the warp and weft. As the leno yarn, yarns having the characteristics shown below are particularly preferred. That is, () A leno yarn whose strength is 10% or more per unit denier than the warp and weft yarns constituting the base fabric.

() Leno yarn whose breaking work is 10% or more greater than the warp and weft yarns that make up the base fabric.

() Leno yarn whose elongation at break is 5% or more greater than the warp and weft yarns that make up the base fabric.

() A leno yarn that has less adhesion to the resin coating than the warp and weft yarns that make up the base fabric.

Among these, the tangles whose strength per unit denier is 10% or more greater than that of the warp and weft are:
Preferably one that is 20-30% larger is used,
Virtually reduces the progress of tearing that occurs in warp and weft yarns.
It is intended to be stopped by a large leno thread that is 10% stronger or more, and since the leno thread is longer than the warp and warp threads, and therefore has a greater degree of freedom in change and deformation than the warp threads, it is possible to continuously It is capable of flexibly dealing with and absorbing tearing forces acting on the sheet. In other words, even if a tear force acts on the sheet and causes the warp and warp threads to displace and eventually break, the leno threads follow the tear force and are displaced and deformed without being cut, and the energy of the tear is eventually absorbed and the tear occurs. It can be stopped.

Next, as a leno yarn, the breaking work is preferably 10% or more, more preferably 20 to 30%, than the warp and warp yarns.
% yarn can be used. The breaking work here is a value approximately expressed by the product of the strength at the time of cutting the yarn and the elongation at the time of cutting.

Work at break = Tensile strength at break x Tensile elongation at break For example, polyester filament yarn with a tensile strength at break of 8.0 g per unit denier and a tensile elongation at break of 13% per unit denier is used as the warp and warp threads, and as a leno yarn, the unit A polyamide fiber yarn with a denier of 7.0 g and a tensile elongation at break of 18% is used. At this time, the breaking work of the leno yarn is about 21% greater than that of the warp and warp yarns. Furthermore, in consideration of ease of processing, it is desirable to use threads made of the same material.

Furthermore, a leno yarn having a breaking elongation that is preferably 5% or more higher than that of the warp and warp yarns can also be used for the braided connection. When polyester filament yarn is used, the breaking elongation of the warp and warp yarns is preferably 15% or less, especially 8 to 12%, while the breaking elongation of the leno yarn is 15% or more, especially 20% or more, and there is no difference between the two. A difference of at least 5% or more gives good results. When the leno thread is a synthetic fiber, the degree of polymerization of the polymer material is adjusted at the time of manufacture to maintain a desired strength and a desired high elongation at break; A filament with a lower drawing ratio, for example, an undrawn yarn, or a leno yarn having a desired elongation at break can be obtained by crimping during secondary processing.

Furthermore, it is also possible to use leno threads that have a smaller adhesion force to the coating resin material than warp and warp threads. In this case, the leno thread may have its surface subjected to silicon processing or the like. In this case, the warp and warp threads are bonded to the coating resin material,
The degree of freedom for displacement and deformation decreases, but the degree of freedom for the leno thread is greater than that for the warp and warp threads, and when tearing force acts on the base fabric, the leno thread slips and is displaced and deformed. Therefore, tearing of the base fabric can be prevented.

In order to reduce the adhesive strength, as mentioned above, the surface of the leno thread should be subjected to non-adhesive treatment such as silicone treatment or oil treatment, or it should be treated with a material that is inherently adhesive, such as polyethylene thread and polypropylene thread. It is sufficient to use a small thread.

As described above, in the base fabric according to the present invention, it is preferable that the leno yarns for connecting the warp and warp yarns arranged in parallel in the warp and warp directions are substantially longer than the warp and warp yarns, and that the leno yarns are substantially longer than the warp and warp yarns. Even if the yarn is cut or displaced, at least a part of it is long enough not to break, is strong, has a large amount of work at break, and/or has a large elongation at break, or has adhesive strength. The tensile strength is maintained by the warp and warp yarns, and the leno threads are used to resist the impact force at the time of tearing or to absorb the tearing energy. absorb and further
By leaving the leno threads uncut, delamination between the resin coating and the sheet due to tearing can be prevented.

Regarding the special structure fabric according to the present invention, furthermore,
Related to the applicant's earlier application Fabrics described in JP-A-54-139688), JP-A-55-134242, JP-A-56-159165, JP-A-57-14031, JP-A-57-14032, etc. can be suitably used. These textiles typically have a structure as shown in FIG. In the figure, 1 is a warp, 2 is a weft, and 3 is a leno thread.

That is, the base fabric used in the present invention is useful for maintaining the mechanical strength of the resulting laminate at a high level.

In the laminate of the present invention, an intermediate layer made of a soft polyvinyl chloride resin is coated on one or both sides of the special structure woven base fabric. This intermediate layer has a thickness sufficient to give the laminate desired flame retardancy, waterproofness, and mechanical strength, for example, a thickness of 0.05 mm or more, preferably 0.05 to 1.0 mm. It is.

The middle layer is a soft polyvinyl chloride resin film,
Alternatively, it can be formed on the base fabric using a paste, a straight material, or the like, by a conventionally known method such as topping, calendering, coating, dipping, or the like.

The soft polyvinyl chloride resin may contain plasticizers, stabilizers, colorants, ultraviolet absorbers, and other functional agents.

An acrylic resin surface layer is formed on at least one of the intermediate layers. The acrylic resin is preferably one mainly composed of polyalkyl methacrylate. The polyalkyl methacrylate resin is preferably a single polymer of methyl methacrylate, ethyl methacrylate, propyl methacrylate, or butyl methacrylate, or a copolymer of two or more of these. Acrylic resin contains alkyl acrylate, vinyl acetate, vinyl chloride,
A small amount of a single polymer such as styrene, acrylonitrile, methacrylonitrile, or a copolymer of two or more thereof may be mixed, or the above monomer may be copolymerized with the above alkyl methacrylate.

An acrylic resin surface layer is formed on the at least one intermediate layer by methods known in the art.

The important features of the present invention include the use of a specially structured woven base fabric as described above, and the formation of an acrylic film layer on the top surface of the PVC resin layer.

The acrylic film layer provides weather resistance and stain resistance to the laminate. In particular, it prevents the plasticizer contained in the PVC layer from bleeding, and does not cause surface decomposition products of the layer or surface tackiness due to the bleeding. The acrylic film may be made using the T-die method, the inflation method, or any other method. Further, it may be either stretched or unstretched. Usually, the thickness is about 10μ to 50μ.

Such films can be attached using adhesives, but the surface is melted by heating.
It is particularly preferable to melt and tack it onto the surface of the PVC layer while heating it to, for example, about 140°C.

The laminate thus obtained exhibits less cracking in cold weather than laminates made from conventional textiles, such as plain weave fabrics. That is, while the conventional product can be used at approximately 5°C to -5°C, the product of the present invention can be used at -20°C to -25°C. Furthermore, in some cases,
It can also be used at lower temperatures. This seems to be due to the fact that in the product of the present invention, the directionality of bending due to the base fabric structure is not particularly limited and can be bent in all directions, and is flexible. As a result, it seems that one of the reasons for the good results is that even when the acrylic film is attached, the laminate does not become harder than necessary.

In the laminate of the present invention, the acrylic resin surface layer has a thickness within the range of 10 to 50 microns, and a large number of convex portions and concave portions are formed on the surface,
The height difference between the highest point of each convex portion and the lowest point of each adjacent concave portion is 5 microns or more, preferably 7 microns or more.

If the thickness of the surface layer is less than 10 microns, it will not be possible to sufficiently eliminate the defects of the polyvinyl chloride resin intermediate layer, and if the thickness of the surface layer is greater than 50 microns, the flexibility of the resulting laminate will deteriorate. Flexibility becomes unsatisfactory. Furthermore, if the difference in height between the highest point of the convex portion and the lowest point of the concave portion is less than 5 microns, the effect of improving flexibility by forming the unevenness becomes unsatisfactory.

There are no particular limitations on the shape and dimensions of the concave portions and convex portions formed in the surface layer as long as the objective of the present invention can be achieved, but the dimensions per horizontal area cm ² of the surface of the surface layer are not particularly limited.
It is desirable that 100 to 1,000,000 protrusions are formed.

To form the acrylic resin surface layer on the polyvinyl chloride resin intermediate layer, first prepare an acrylic resin film having a desired uniform thickness, and place it on a smooth table or roll with a smooth peripheral surface. This is pressed with a shaping plate or a shaping roll engraved with an uneven pattern of a predetermined shape and size to form desired unevenness on one side of the acrylic resin film. Of course, the uneven pattern may be formed on both sides of the film.

The acrylic resin film prepared as described above and having irregularities on at least one side may be adhered to the polyvinyl chloride resin intermediate layer using an adhesive, or the surface portion of the intermediate layer may be bonded to the polyvinyl chloride resin intermediate layer. For example, 140℃～
This may be heated to 200° C. to melt it, and then an acrylic resin film may be pressed and adhered thereon. Alternatively, an acrylic resin film may be adhered onto the intermediate layer by the method described above, and the resulting acrylic resin surface layer, such as a laminated layer, may be shaped to have concavities and convexities similar to those described above.

The unevenness formed on the shaped surface (peripheral surface) may correspond to the uneven pattern to be imparted to the acrylic resin surface layer, and when forming the unevenness, the acrylic resin surface layer is It is preferable to heat to a temperature within the range of 30° C. above the glass transition point (Tg) to 10° C. below its melting point (Tm). For this purpose, the acrylic resin film (or surface layer) may be heated to a desired temperature in advance and subjected to the shaping process, and/or the shaping plate (roll) may be heated to the desired temperature.

The laminate of the present invention shown in FIGS. 2 and 3 is similar to the laminate shown in FIG.
However, a large number of fine irregularities are formed on the surface of the acrylic resin surface layer 6 formed on the intermediate layer 5.

In the laminate of the present invention shown in FIGS. 2 and 3, the surface layer 6 is formed only on the intermediate layer 5, but other surface layers are formed on the intermediate layer 5'. Good too.

The bonding surface between the intermediate layer and the surface layer may be smooth as shown in FIG. 2, or may be uneven as shown in FIG. 3. In the latter case, the adhesive strength of both layers increases.

Also, a portion of the polyvinyl chloride resin may penetrate into the special structure fabric base fabric. In this case, the adhesive strength between the base fabric and the intermediate layer increases.

The laminate obtained in this way also has excellent flex cracking resistance in cold weather and stability in use, and its performance is approximately -5°C higher than that of a laminate without surface irregularities. It will be improved.

Effects of the Invention In the laminate of the present invention, the acrylic resin surface layer covers the special structured textile base fabric and the polyvinyl chloride resin intermediate layer to improve the weather resistance of the laminate, and Not only does this prevent the plasticizer from bleeding onto the surface of the laminate, thereby improving the antifouling properties of the laminate, but the numerous minute irregularities formed on the surface of the acrylic resin surface layer also improve the resistance of the laminate. Flexibility can be further improved and cracking of the surface layer can be prevented. Therefore, the laminate of the present invention can be used for a long period of time without causing surface cracks or stains.

The laminate of the present invention is based on the above characteristics,
It is suitable for outdoor sheets such as tents, vehicle tops, and outdoor storage tops, and can be subjected to severe bending, especially under strong winds, and can exhibit its remarkable effects.

Further, since the acrylic resin surface layer has a thickness of only 50 microns at most, the laminate of the present invention can be welded.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing one embodiment of the base fabric useful in the present invention, and FIGS. 2 and 3 are cross-sectional explanatory diagrams of one embodiment of the laminate of the present invention, respectively. 1... warp, 2... weft, 3... twine, 4
...Base fabric, 5,5'...PVC intermediate layer, 6...Acrylic resin surface layer.

Claims (1)

[Scope of Claims] 1. A warp layer consisting of a large number of warps arranged parallel to each other, a weft layer consisting of a large number of wefts arranged parallel to each other so as to be orthogonal to the warps, and the warp and weft and leno threads entangled and bonded at their intersections; an intermediate layer formed on at least one surface of the base fabric and made of a soft polyvinyl chloride resin; and an intermediate layer formed on the intermediate layer. and a surface layer made of acrylic resin, the thickness of the surface layer is within the range of 10 to 50 microns, and a large number of convex portions and concave portions are formed on the surface of the surface layer. An acrylic resin laminate with excellent bending resistance, characterized in that the height difference between the highest point of each convex portion and the lowest point of each adjacent concave portion is 5 microns or more. 2. The laminate according to claim 1, wherein the surface layer has 100 to 1,000,000 convex portions per cm ² of horizontal surface area of the surface layer.