JPH02196643A - Flexible laminate - Google Patents

Abstract

PURPOSE:To manufacture a fluorine resin flexible laminate of superior flexing resistance, particularly in the cold season, elasticity, resistance to weather, resistance to oils and antifouling by forming a thick polyurethane resin layer or layers on a surface or the surface and rear surface of a base cloth of a special structure fabric constituted of warp layers consisting of a number of warps in parallel, weft layers consisting of a number of wefts in parallel crossing warps and interlocking yarns interlocking and connecting crossings and forming a thick fluorine resin film layer on the upper surface of a surface layer. CONSTITUTION:A laminate includes a special structure fabric base cloth, a polyurethane intermediate layer formed on one surface of the base cloth and a fluorine resin surface layer formed on said intermediate layer. The base cloth is constituted of natural fibers such as cotton and linene and synthetic fibers such as nylon 6 and others, and the fibers are arranged respectively in parallel, and laminated in a manner that warp layers and waft layers formed with the fibers are crossed with each other and connected loose at the crossings of warps and wefts by means of long interlocking yarns. The interlocking yarns are selected out of synthetic fibers such as polyester and nylon and inorganic fibers such as glass fibers and steel fibers. The generation of cracks in the cold season for the laminate thus prepared is less than for a laminate using plain weave fabric as base cloth this arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a fluororesin laminate having excellent bending resistance. More specifically, the present invention relates to a flexible laminate having excellent bending resistance, flexibility, weather resistance, oil resistance, stain resistance, and durability. The present invention relates to a laminate comprising a specially structured woven base fabric, a polyurethane layer, and a fluororesin layer, which has excellent resistance to flex cracking especially in cold weather.

[Conventional technology]

Conventionally, flexible laminated sheets made of fiber base fabrics, especially plain woven base fabrics, coated with a polyurethane resin layer on one or both sides, have been used for oil-resistant aprons, tarpaulins, etc. due to their versatility, oil resistance, economic efficiency, and other aspects. ing.

Although this sheet essentially has the advantages of polyurethane resin, such as processability, economy, and oil resistance, on the other hand, during long-term use, sufficient consideration must be given to stabilizers, etc. However, the resin gradually decomposes, causing discoloration from the surface layer, and furthermore, a large amount of dust adheres to the surface, resulting in severe contamination, etc., and has serious drawbacks in terms of weather resistance, stain resistance, etc. Met.

As a countermeasure to the above-mentioned drawbacks of conventional laminated sheets, the present applicant discovered that considerable effects could be achieved by forming a fluorine-based resin film layer on the polyurethane layer. I applied. However, even in such a laminate, if it is rubbed very strongly during use, cracks will occur in the thin resin film layer, and if this is further expanded, cracks will also occur in the underlying polyurethane layer. It has been found that this phenomenon is particularly noticeable in cold weather, and therefore has drawbacks such as significantly shortening the service life of the laminate.

[Problem to be solved by the invention]

In view of the above circumstances, the present invention was made in order to eliminate the drawbacks of conventional laminated sheets.
We investigated ways to prevent cracks in the surface layer by dispersing the stress applied to the resin layer, especially the surface layer made of fluorine-based resin, due to Knitted fabrics with a high degree of expansion and contraction are unsuitable, and plain weave fabrics with a low degree of expansion and contraction under load are advantageous, but when such a woven fabric is made into a laminate as described above, the stress applied to the fluororesin layer is large. The inventors have discovered that this makes it easy for cracks to occur due to the base fabric, and have completed the present invention by solving such inconveniences.

An object of the present invention is to provide a fluororesin flexible laminate that has excellent bending resistance, especially in cold weather, and also has excellent flexibility, weather resistance, oil resistance, and stain resistance. be.

[Summary of the invention]

According to the present invention, a fluororesin laminate with excellent bending resistance is provided, and this laminate has a warp layer consisting of a large number of warp threads arranged parallel to each other, and a warp layer arranged perpendicularly to the warp threads. A polyurethane resin is applied to the surface or front and back surfaces of a base fabric of a special structure fabric consisting of 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 and weft yarns at their intersections. A thin fluororesin film layer is formed at least on the upper surface of the surface layer.

The laminate of the present invention comprises a specially structured woven fabric base fabric, an intermediate layer made of a polyurethane resin formed on at least one surface thereof, and a fluororesin surface layer formed on this intermediate layer. It is something.

The special structure fabric 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, etc.
cupro, semi-synthetic fibers such as g- 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 polyolefins. It is made of at least one type selected from fibers, etc. 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 yarn is selected from polyester, nylon, aromatic polyamide and other known synthetic fibers, glass fiber, steel fiber and other known inorganic fibers, and polyester filament yarn is particularly preferred.

For example, for warp and warp yarns, tensile strength of single yarn is 1 or 3.
If kg of Vinylon 103/1 spun yarn is used, an aromatic polyamide filament yarn with a tensile strength of 20 g per unit denier is used as the leno yarn, and
When using threads of the same material in consideration of ease of fabrication, for example, polyester filament yarn with a tensile strength of 8 g per unit denier is used as the warp and warp threads, and polyester filament yarn with a tensile strength of 8 g per unit denier is used as the leno yarn. Use yarn.

A particularly preferable structure of the special structure fabric for use in the present invention is as described in Japanese Patent Publication No. 30381/1989 filed by the present applicant, including a warp layer consisting of a large number of warp threads arranged in parallel to each other; It consists of a weft layer consisting of a large number of weft yarns arranged in parallel to each other so as to be perpendicular to the warp yarns, and a leno yarn that entangles and connects the warp yarns and weft yarns at their intersections. The leno threads are longer than the warp and weft threads, and therefore,
The warp and weft are loosely connected (and at least one of their tensile strength, tensile elongation, and breaking work is greater than that of the warp and weft, and/or adhesive strength to the resin material) is preferably smaller than that of the warp and weft. As the leno yarn, yarn having the characteristics shown below is particularly preferable. Namely, (i) its strength is lower than that of the warp and weft constituting the base fabric. However, it is a 10% or more large leno yarn per unit denier.

(ii) A leno yarn whose breaking work is 10% or more greater than that of the warp layer and weft that make up the base fabric.

(iii) A leno yarn whose elongation at break is 5% or more greater than that of the warp and weft yarns constituting the base fabric.

(iv) A leno yarn that has a lower adhesion force to the resin coating than the warp and weft yarns constituting the base fabric.

Among these, leno yarns with a tenacity per unit denier of at least 10% greater than that of the warp and weft are preferably used by at least 20 to 30%, so as to substantially prevent the progress of tearing that occurs in the warp and weft. The purpose is to use large leno threads that are 10% stronger or more strong, and the leno threads are longer than the warp and warp threads, so they have a greater degree of freedom in change and deformation than the warp threads. It flexibly deals with and absorbs the tearing force that acts on the material.

In other words, even if a tearing force acts on the sheet, causing the warp and warp threads to displace and eventually break, the leno threads follow the tearing force, displace and deform without being cut, and eventually absorb the tearing energy and stop tearing. can be done.

Next, as the leno yarn, a yarn whose breaking work is preferably 10% or more, more preferably 20 to 30% higher than the warp and warp yarns 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
A polyester filament yarn having a tensile elongation of 18% and a tensile elongation of 7.0 g per unit denier is used as the leno yarn. At this time, the breaking work of the leno yarn is approximately 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 elongation at break of the warp and warp threads is preferably 15% or less, particularly 8 to 12%, while the elongation at break of the leno thread is preferably 15% or more, especially 20%.
In the above, a difference of at least 5% between the two 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 leno yarn having a desired elongation at break can be obtained by lowering the drawing ratio of the filament, for example, an undrawn yarn, or a leno yarn having a desired elongation at break 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
Due to adhesion with the coating resin material, its degree of freedom of displacement and deformation is reduced, but the degree of freedom of the leno yarn is greater than that of the warp and warp yarns, and when a tearing force is applied to the base fabric, the leno yarn slips. It can be moved and deformed, and thus prevents the base fabric from tearing.

In order to reduce the adhesive force, the surface of the leno thread should be treated with non-adhesive treatments such as silicone treatment or oil treatment, or the surface of the leno thread should be treated with a non-adhesive treatment such as polyethylene thread and polypropylene thread (which are essentially small threads with adhesive properties). You can use the article.

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, it is long enough that at least a part of it will not 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 force is maintained at high strength by the warp and warp threads, and the leno threads are used to resist the impact force at the time of tearing or absorb the tear energy. Furthermore, 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, please refer to Utility Model Publication No. 52-50234 (Utility Model Application Publication No. 50-1668) related to the applicant's earlier application.
, Japanese Patent Publication No. 57-30381 (Japanese Patent Publication No. 57-67446)
No.), Special Publication No. 55-24415 (Japanese Patent Publication No. 54-139)
Fabrics described in JP-A-55-134242, JP-A-56-159165, JP-A-57-14031, and JP-A-57-14032 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 obtained laminate at a high level.

In the laminate of the present invention, one or both sides of the special structure fabric base fabric is coated with an intermediate layer made of polyurethane resin.

The shape of the polyurethane resin used in the present invention can be freely selected, and plasticizers, stabilizers, colorants, lubricants, and various other tactile agents can be freely added within known ranges.

An example of polyurethane resin, particularly thermoplastic polyurethane elastomer resin, will be shown below.

As the polyurethane elastomer, one obtained by reacting an organic polyisocyanate with a polymeric polyol and, if necessary, a chain extender is used.

Organic polyisocyanates include aliphatic, cycloaliphatic or aromatic polyisocyanates, such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexylene diisocyanate, dicyclohexylmethane diisocyanate, inphorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate,
Examples include phenylene diisocyanate, diphenylmethane diisocyanate (MDI), biphenylene diisocyanate, and naphthylene diisocyanate. MDI or an organic diisocyanate mainly composed of MDI is preferred.

Polyether polyols include polyether polyols,
Mention may be made of polyester polyols, polyether ester polyols, polymer polyols and mixtures of two or more thereof.

Polyether polyols include those obtained by polymerizing or copolymerizing (block or random) alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.), heterocyclic ethers (tetrahydrofuran, etc.), such as polyethylene glycol, polypropylene glycol. , polyethylene-propylene (block or random) glyconepolytetramethylene ether glycol, polyhexamethylene ether glycol, polyoctamethylene ether glycol and mixtures of two or more thereof. Examples of polyester polyols include dicarboxylic acids (adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycols (ethylene glycone propylene glycol, 1,4-butane dione, 1°6-hexane). Diol, 1,8-octamethylene diol, neopentyl glycol, bishydroxymethylcyclohexane, bishydroxyethylbenzene,
(alkyl dialkanolamine, etc.), such as polyethylene adipate, polybutylene atovate, polyhexamethylene adipate, polyethylene/propylene adipate: polylactone diol, such as polycaprolactone diol: and two types thereof. Mixtures of the above may be mentioned. As the polyether ester polyol, ether group-containing diols (the polyether diols, diethylene glycol, triethylene glycol, triethylene glycol, etc.) or mixtures of these with other glycols are combined with the dicarboxylic acids or dicarboxylic anhydrides (phthalanhydride, etc.). acid, maleic anhydride, etc.) and alkylene oxide, such as poly (polytetramethylene ether) adipate.

In addition, as a polymer polyol, a polymer polyol (
Examples include those obtained by polymerizing ethylenically unsaturated monomers (acrylonitrile, styrene, etc.) in the above-mentioned polyether polyols, polyester polyols, and/or polyether ester polyols) or mixtures of these and medium- to low-molecular-weight diols. .

Average molecular weight of polymer polyol (by hydroxyl value titration)
is usually 500 to 50 (10, preferably 700 to 400
0, particularly preferably 2000 to 3500.

As a chain extender, low-molecular polyols with a molecular weight of less than 500, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1°6-hexanecyonopediethylene glycol, triethylene glycol, thiodiglycol (thiodiethanol), etc. etc.): polyamines, for example aliphatic diamines such as ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, cycloaliphatic polyamines such as piperazine, 1,4-diaminopiperazine, 1,3-cyclohexylene diamine, dicyclohexylmethane diamine, etc. , aromatic polyamines such as diphenylmethanediamine, tolylenediamine, phenylenediamine, aromatic-aliphatic polyamines such as xylylenediamine, hydrazine and monoalkylhydrazine: alkanolamines, such as ethanolamine, propatoolamine: and two of these.
Examples include mixtures of more than one species. Preferred are low molecular weight diols (especially ethylene glycol).

However, any other thermoplastic polyurethane resin can be used without being limited to the above examples. This intermediate layer has a thickness sufficient to give the laminate the desired oil resistance, waterproofness, and mechanical strength, for example, 0.05 mm or more, preferably 0.05 to 1.0 mm. It has a thickness of 0 mm.

The polyurethane resin formed on the surface or front and back surfaces of the base fabric is not only used as an adhesive, but also has a sufficient thickness, for example, 0.05 to 1.5 mm, in order to maintain oil resistance, abrasion resistance, and other necessary physical properties. It is necessary to have a thickness of 0 mm. It may be thicker if it is financially acceptable. The polyurethane resin layer is formed by topping, calendering, coating, or other methods. The shape of the polyurethane resin when used can be freely selected, and it goes without saying that plasticizers, stabilizers, colorants, lubricants, and various other tactile agents can be freely added to the resin within known ranges.

The polyurethane resin may contain air bubbles.

Furthermore, depending on the application, the base fabric and the polyurethane resin intermediate layer may each be composed of a plurality of pieces.

A fluorine-based resin film surface layer is formed on at least one of the intermediate layers. Next, this fluorine-based resin film, which is the most important feature contributing to the present invention, will be explained.

In general, fluorine-based resins are nonflammable and have excellent chemical resistance, so they can be used for backings, tubes, sheets, etc.
In addition to products, it is also used for electrical equipment parts, linings, etc. However, this resin has a high degree of crystallinity and is not compatible with ordinary plastic adhesives, so it is extremely difficult to adhere it to the surface of a synthetic resin as it is.

In the present invention, a fluorine-based resin film is subjected to a surface corona discharge treatment or the like to activate the surface as rough as possible, thereby producing a resin adhesive such as vinyl chloride, epoxy, acrylic, polyester, etc., or a mixture of these resins. It may also increase compatibility with adhesives. Usually, the above-mentioned treatment results in roughening of the surface portion of the fluororesin film having a thickness of 2 to 10 microns. For this purpose, the discharge treatment is performed under the conditions of 100 to 200 V DC, 40 to 100 μF, and 1 to 2 A short final current. Such discharge treatment allows the fluorine-based resin film to obtain the desired adhesion ability, but the surface treatment of the fluorine-based resin film used in the present invention is not limited to this, and other surface treatments can be used to obtain the same or higher effect. It is fine as long as it plays.

The fluorine-based resins constituting the fluorine-based resin film include various polyfluoroethylenes synthesized from monomers in which one or more hydrogen atoms of ethylene are replaced with fluorine atoms, such as:
Polytetrafluoroethylene or various polyfluorochloroethylenes containing some chlorine, such as polytrifluorochloroethylene, but also polyvinyl fluoride, polyvinylidene fluoride, polydichlorodifluoroethylene, and others is also included. All of these fluorine-based resins have high melting points, so normal calendar processing cannot be performed, so they are generally melted and then extruded, or powdered resin is heated under pressure and molded into a sheet. However, there are no particular limitations on the film forming method. The thickness of the fluororesin film layer is preferably 50 μm or less, but it may be thicker than the above or It can be made thinner.

In the present invention, a fluorine-based resin in the form of a film with a substantially smooth surface may be adhered to the upper surface of the polyurethane resin layer, but it is also possible to apply a fluorine-based resin solution such as an emulsion or solinyion. There is a way. With this method, the paint film is thin and it is difficult to apply the thickness uniformly, which often results in uneven coating, and some areas are left uncoated, making it impossible to expect a complete effect and causing stains. It also adheres easily. Furthermore, since the strength of the coating film is weak, the fluororesin film may be partially damaged by scratching or the like during use, which poses a problem in terms of durability. The film strength of the fluororesin film according to the present invention is usually preferably 100 kg/cI11 or more.

The fluorine-based resin surface layer is coated with at least one layer by a conventionally known method.
formed on two intermediate layers. The important features of the present invention include the use of a specially structured woven base fabric as described above, and the formation of a fluororesin film layer on the top surface of the polyurethane resin layer.

The fluororesin film layer also imparts weather resistance and stain resistance to the laminate. In particular, bleeding of the plasticizer contained in the polyurethane resin layer is suppressed, and the formation of surface decomposition products of the core layer and surface tackiness due to the bleeding are not caused. The fluororesin film may also be produced by the T-die method, the inflation method, or any other method. Further, it may be either stretched or unstretched, and its thickness is usually about 3 μm to 50 μm.

As mentioned above, such a film can be attached using an adhesive, but it can be attached to the surface of a polyurethane resin layer whose surface has been melted by heating, for example, by applying a melt tack to the surface of the polyurethane resin layer heated to about 200°C. You can also attach it.

FIG. 2 shows a specific example of the laminate according to the present invention, in which polyurethane resin layers 5 and 5' are formed on both sides of the base fabric 4. A fluororesin film layer 6 is provided on the upper surface. The polyurethane resin layer 5' on the back surface may be omitted, or the fluorine-based resin film layer 6 may be provided also on the back resin layer 5'. The laminate thus obtained exhibits less cracking in cold weather than laminates made from conventional textiles, such as plain weave fabrics. In other words, for conventional products, the standard operating conditions are approximately 5 to -5 degrees Celsius, but
The product of the present invention can be used even at -20°C to -25°C. Furthermore, depending on the case, it can be used even 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. In addition, Scott type bending test (JrS-
-6328-1981, 5, 3, 8) results are also favorable, with the number of cracks occurring approximately 5 to 10 times.

In particular, it is preferable for the fluorine-based resin film to be thin for practical purposes.
The fact that this effect is remarkable in the range of ~20μ is an epoch-making effect compared to conventional products.

As a result, it is thought that one of the reasons for the good results is that the laminate does not become harder than necessary even when a fluororesin film is applied.

[Effects of the Invention] In the laminate of the present invention, the fluororesin surface layer coats the special structured woven fabric base fabric and the polyurethane resin intermediate layer to improve the weather resistance of the laminate, and the fluororesin surface layer covers the special structure textile base fabric and the polyurethane resin intermediate layer, and Prevents plasticizer from bleeding to the body surface, thereby improving the stain resistance of the laminate.

Since the present invention is based on the above-described structure, the present invention does not impair the advantages of conventional polyurethane sheets, and furthermore, a polyurethane resin is formed on a base fabric, and a fluorine-based resin film is further formed on the top surface of the base fabric. In this case, a laminate with significantly superior flexibility, durability and strength will be constructed. The laminate of the present invention can be used for tents, canopies, sheets, flexible containers, wide belts, food conveyance belts, aprons, cloaks,
It has a particularly remarkable effect when used for leather, oil fences, and other industrial materials. In particular, the effect can be particularly exhibited in canopies, seats, etc., which are subjected to severe bending action under strong winds, and belts, etc., which are subject to many bending actions.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the base fabric useful in the present invention, and FIG. 2 is a cross-sectional explanatory diagram of one embodiment of the laminate of the present invention. 1... warp, 2... weft, 3...
Leno thread, 4... Base fabric, 5.5'... Polyurethane intermediate layer, 6... Fluorine resin surface layer.

Claims (1)

[Scope of Claims] 1. 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 perpendicular to the warps, and the warp and weft. and,
A sufficiently thick layer of polyurethane resin on the surface or front and back surfaces of a specially structured woven base fabric consisting of leno threads that are entangled and bonded at their intersections, and at least on the surface of the polyurethane resin layer formed on the surface side. A flexible laminate having a fluorine-based resin film layer. 2. The laminate according to claim 1, wherein the fluororesin film layer has a thickness of 50 microns or less. 3. The laminate according to claim 1, wherein the fluorine resin film is a fluorine resin film made of polyvinyl fluoride, polyvinylidene fluoride, or polytetrafluoroethylene.