JPH0847994A - Lightweight ultra-strong sheet and production thereof - Google Patents

Abstract

PURPOSE:To obtain a lightweight inexpensive ultra-strong sheet by constituting the sheet of a two-layered laminated structure of a stretched material selected from a biaxial or multi- axial yarn laminated nonwoven fabric obtained from a tape with tensile strength of a specific value or more composed of ultra-high mol.wt. polyethylene with intrinsic viscosity of a specific value or more and a longitudinal and lateral laminated nonwoven fabric of wide reticulated webs and a sheet material. CONSTITUTION:Ultra-high mol.wt. polyethylene with intrinsic viscosity of 5dl/g or more (measured in a decalin soln. at 135 deg.C) is stretched to form a stretched material with tensile strength of 1.0 GPa or more and this stretched material is formed into a tape form and a number of the obtained stretched tapes are laminated so that the orientation axes of them cross each other at a right angle and thermally fused at intersecting points to obtain a biaxial or multiaxial yarn laminated nonwoven fabric 2. The stretched material is split under tension by a splitter to be formed into a reticulated web shape and a number of the obtained wide split webs are laminated longitudinally and laterally through an adhesive to form a nonwoven fabric 2. Non-combustion or fire-retardant sheet materials 3, 4 are laminated to both surfaces of the yarn laminated nonwoven fabric 2 or the longitudinally and laterally laminated nonwoven fabrics of the wide reticulated webs through an adhesive to obtain an ultra-strong sheet 1.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is applied to canvases that can be used for tents, yachts, flexible containers, etc., or protective sheets, explosion-proof sheets, etc. used at construction sites, construction sites, demolition of buildings such as concrete, etc. Lightweight, high-strength seats.

[0002]

2. Description of the Related Art Conventionally, construction sites, construction sites, high-strength sheets such as protective sheets for concrete dismantling or explosion-proof sheets have been made of tarpaulins obtained by coating resin on a fabric made of polyester fiber or polyamide fiber. There were problems such as low strength and low elastic modulus. In recent years, woven fabrics of highly elastic fibers made of liquid crystal fibers such as drawn yarns of ultra-high molecular weight polyethylene, Kepler fibers, and Vectran fibers, or tarpaulins obtained by coating the woven fabrics with resin have been used. However, since they are all formed from woven fabric, the threads intersect, and if the weave density of the woven fabric is not densely woven, laughter will occur in the tissue, resulting in thickening,
It has the drawback of poor handling and workability. Also,
Not only is the cost of weaving a woven fabric of high elastic fibers high, but it is difficult to weave due to its high elastic modulus, and the amount of high elastic modulus yarns used is large, which causes a problem of high cost.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of intensive studies for solving the above-mentioned problems, and provides an ultra-high molecular weight polyethylene ultra-stretched body of high strength, high elastic modulus and lightweight. Taking advantage of the rupture resistance to cutlery, cement debris, metal debris, etc., and the flatness and thinness of ultra-high molecular weight polyethylene stretched tape and reticulated web,
The purpose of the present invention is to provide an ultra-strong sheet that is inexpensive, thin, flexible, and easy to handle and work.

[0004]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in view of the above-mentioned object, as a result of integrating an ultra-high molecular weight polyethylene ultra-stretched body and a sheet material with an adhesive, it is possible to reduce the weight. The present invention has been accomplished by finding that an inexpensive super-strong sheet can be obtained.

That is, the present invention has a tensile strength of at least 1.0 GPa made of ultra high molecular weight polyethylene having an intrinsic viscosity of 5 dl / g or more when measured in a 135 ° C. decalin solution.
It is characterized by comprising a laminated structure of at least two layers of at least one kind of stretched material selected from biaxial or multiaxial yarn laminated non-woven fabric composed of the above tapes and wide-mesh web-woven latitudinal laminated non-woven fabric. It is a lightweight and super strong sheet that does.

In the present invention described above, the sheet material is preferably a non-combustible or flame-retardant sheet, and in the yarn-laid nonwoven fabric and the weft-laid nonwoven fabric of web, the porosity of the laminated structure is 30. %, And it is more preferable that the sheet material has a large number of fine holes of 5 mm or less.

In the present invention described above, since the filaments forming the yarn and the web intersect linearly, there is no bending of the yarn unlike woven cloth or random nonwoven cloth, and the strength and elastic modulus of the filament are effective. As a result, a sheet having sufficient strength and elastic modulus can be obtained even if it is thin.

Since the filaments of the non-woven fabric of the present invention intersect linearly, various structures can be obtained.
Despite its small amount of fibers, it has high strength and high dimensional stability, and therefore it is lightweight and can sufficiently fulfill its purpose as a protective sheet. With conventional woven fabrics and random nonwoven fabrics, it is difficult to make such a coarse structure, and in order to make a coarse woven fabric, a means such as a entangled weave is required, but it only increases the cost. However, the disadvantage is that the thickness of the woven fabric increases.

Further, the thin web is not only lightweight in itself, but also the film for laminating it is thin, which makes the web lighter and less expensive as a whole. In particular, it is desirable that the film to be laminated of the present invention be flame-retarded, and as a result, thinning has a great effect of reducing the cost.

The present invention will be described in detail below.

The ultrahigh molecular weight polyethylene of the present invention has an intrinsic viscosity of 5 dl / g or more (measured with a decalin solution at 135 ° C.), preferably in the range of 5 to 50 dl / g, preferably 5 to 40 dl / g. , And more preferably 10
It has a viscosity average molecular weight in the range of 500,000 to 12,000,000, preferably 900,000 to 9,000,000, and more preferably 1,200,000 to 6,000,000.

When the intrinsic viscosity is less than 5 dl / g, the mechanical properties of the stretched product deteriorate, and when it exceeds 50 dl / g, the workability is deteriorated, which is not preferable.

The shape of the ultra-high molecular weight polyethylene is not particularly limited, but in order to obtain a homogeneous film by post-processing, normally, granular or powdery one is preferably used.

The particle size of these is 2000 μm or less, preferably 1 to 2000 μm, more preferably 10 to 100.
0 μm is desirable. Further, it is preferable that the particle size distribution is narrow, because there are few defects when compression-molding to form a sheet.

The ultra-high-molecular-weight polyethylene of the present invention comprises at least one compound selected from compounds containing transition metals of Groups IV to VI of the periodic table such as titanium compounds, vanadium compounds, chromium compounds, zirconium compounds and hafnium compounds. It is produced by homopolymerizing ethylene or copolymerizing ethylene with an α-olefin having 3 or more carbon atoms, etc. in the presence of a catalyst obtained by combining the contained catalyst component and, if necessary, an organometallic compound.

The α-olefin has 3 to 1 carbon atoms.
2, preferably 3 to 8 are preferably used. Specifically, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-
Dodecene etc. are mentioned.

Of these, propylene, 1-butene, 4-methyl-1-pentene and 1-hexene are particularly preferable. Other comonomers include butadiene, 1,4
-Dienes such as hexadiene, vinyl norbornene and ethylidene-norbornene may be further used in combination.

The α-olefin content of the ethylene / α-olefin copolymer is 0.001 to 10 mol%, preferably 0.01 to 5 mol%, more preferably 0.1.
It is used in the range of ˜1 mol%.

As a method for producing the ultra-high molecular weight polyethylene yarn and the reticulated web constituting the present invention, the present inventors' previous invention, Japanese Patent Laid-Open No. 63-159408, Japanese Patent Laid-Open No. 3-130116, and Japanese Patent Laid-Open No. 5-116116. It can be produced by the method shown in No. 214657.

The method for producing the ultra-high molecular weight polyethylene yarn and the reticulated web constituting the present invention is not limited to the above-mentioned method, but is also a method of super-drawing formed from a melt film or a yarn of a solvent method formed and ultra-drawn. Can also be manufactured from.

Further, as the yarn of the present invention, multifilament yarn, monofilament yarn, tape-shaped filament yarn, split yarn and the like can be used. The reticulated web of the present invention includes not only a wide split web (Figs. 2c and 2f) and a weft laminate (Fig. 2g), but also a weft laminate of webs stretched with zigzag slits at regular intervals before stretching. Including the body (Fig. 2d) and the like.

The biaxial or multiaxial yarn laminated non-woven fabric of the present invention has the structure illustrated in, for example, FIGS. 2a, 2b and 2c, wherein ultra-high molecular weight polyethylene ultra-stretched high-strength, high-modulus yarns are used. It is a structure that intersects with each other at right angles or diagonally. As a method for producing these laminated non-woven fabrics, methods such as JP-B-53-38783, JP-B-62-54904, and JP-B-3-80911 can be used.

A non-woven fabric in which a wide reticulated web is cross-laminated in a weft direction is obtained by splitting an ultra-stretched wide film of ultrahigh molecular weight polyethylene shown in FIGS. 2e and 2f, and expanding the web as shown in FIGS. 2d and 2g. The structure which laminated | stacked the history is shown. The manufacturing method of these split webs and widened laminates thereof are described in JP-B-45-10778 and JP-B-49.
-36048, JP 61-55456, JP 60-
It can be manufactured by means such as 32573.

The strength of the yarn constituting the biaxial or multiaxial laminated nonwoven fabric of the present invention is at least 1.2 GPa.
It is preferable that the above is present, and more desirably 1.5G
Pa or more, and more preferably 1.8 GPa or more.

The reticulated web of the present invention cannot exhibit sufficient strength depending on the method of slitting or splitting, but the filament itself is sufficiently strong. Therefore, as the strength of the web constituting this reticulated web, the value measured by twisting is preferably 1.0 GPa or more, and more preferably 1.5 GPa or more. The strength after twisting depends on the number of twists, and the optimum number of twists is
Depends on the denier when measuring. Generally 1000
The optimum number of twists for a denier filament is around 100 turns / m.

The strength of the yarn and the strength of the web specified in the present invention are the prior inventions of the present inventors, such as JP-A-3-
As shown in No. 130116, for a yarn having a low molecular weight adhesive layer on its surface, a value calculated by the cross-sectional area excluding those adhesive layers is used.

As the sheet material used in the present invention, a thermoplastic resin sheet, a rubber sheet, an inorganic sheet, a metal foil or the like is used. Among these, sheet materials such as non-combustible or flame-retardant sheets and metal foils are preferable. Specifically, high, medium density polyethylene, low density polyethylene, linear polyethylene, ultra low density polyethylene, ethylene-
Vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polypropylene, polyolefin such as propylene-ethylene copolymer, polyamide, thermoplastic resin such as polyester or ethylene-propylene copolymer rubber,
Sheets made by blending ethylene-propylene-diene copolymer rubber, rubber such as SBR with inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide, and organic flame retardants such as chlorine, bromine and phosphorus, polyvinyl chloride , Halogen-containing sheets such as chlorinated polyethylene, and inorganic flexible sheets mainly composed of ultrafine ceramic particles.

The lightweight / super-strength sheet of the present invention is often used in a construction site or the like, and for that purpose, it is desirable that the sheet material used is made flame-retardant or non-combustible.

The method for measuring the non-combustibility and flame retardancy of a sheet is JI
The degree of flame retardancy or noncombustibility can be expressed by the oxygen index at the time of combustion, although it is also defined by S321 of S, etc., and the oxygen index is preferably at least 35 or more, preferably 40 or more, and more preferably 50 or more. .

The laminate of the ultra-high molecular weight polyethylene yarn or web of the lightweight / ultra-strong sheet of the present invention preferably has a porosity of 30%, more preferably 50% or more. By using such a laminate, it is possible to manufacture a sheet having a large number of fine holes. As a construction sheet, a sheet having a structure having a large number of fine holes has a small resistance to a natural wind or a blast, and therefore not only the sheet itself is less damaged but also the entire structure of an object supporting the sheet is damaged. Less. Even if the sheet has fine holes (for example, 5 mm or less), concrete fragments do not penetrate therethrough, and there is no practical problem.

The lightweight / super-strength sheet of the present invention is a thin, light-weight sheet having resistance to cutting force against crushed concrete fragments. The sheet of the present invention is 300 g / m ²
The following light weight, thinness, and lightness make the workability significantly better for transportation at construction sites and sheet folding work.

The flame-retardant sheet for construction up to now is 500
Since it is g / m ² or more, workability is poor. The sheet of the present invention can be easily adjusted to 300 g / m ² or less.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view of an ultra-strength sheet according to an embodiment of the present invention. In FIG. 1, a biaxial or multiaxial yarn laminated nonwoven fabric 2 made of a stretched tape of ultrahigh molecular weight polyethylene or a wide split web is used. The super-strength sheet 1 is obtained by laminating the sheet materials 3 and 4 on both surfaces of the weft-laid nonwoven fabric 2 with the use of an adhesive. The biaxial or multiaxial yarn laminated nonwoven fabric 2 and the wide split web warp-weft laminated nonwoven fabric 2 may be laminated with a sheet material 3 or 4 on only one surface, or a plurality of laminated nonwoven fabrics 2 or 3 And 4 may be combined.

The biaxial or multiaxial yarn laminated nonwoven fabric of the present invention is a yarn laminated nonwoven fabric consisting of biaxial, triaxial, and tetraaxial yarns, and FIGS. 2a to 2g show the ultrahigh molecular weight polyethylene of the present invention. Fig. 2a shows various biaxial or multiaxial yarn laminated nonwoven fabrics and wide reticulated nonwoven fabrics composed of the ultra-stretched body of Fig. 2a. FIG. 2c shows an array diagram of a triaxial yarn laminated nonwoven fabric of ultra-high molecular weight polyethylene drawn tape, and FIG. 2c shows a 4-axis yarn laminated nonwoven fabric of ultra-high molecular weight polyethylene drawn tape. Also,
2d-f are latitudinal and weave nonwovens of various wide reticulated webs of ultra high molecular weight polyethylene.

The above-mentioned lightweight / ultra-strong sheet is produced by A) a step of producing a material for drawing ultra-high molecular weight polyethylene, B) a step of drawing a drawing material, C) a step of forming a drawing material into a tape, and D) drawing. A step of laminating the tape on a biaxial or multiaxial yarn laminated non-woven fabric, E) a step of laminating the laminated non-woven fabric and a sheet material, or A) a step of producing a material for stretching ultra high molecular weight polyethylene , B) a step of stretching a stretching material, C ') a step of forming a stretched film into a wide reticulated web, D') a step of laminating a wide reticulated web on a weft and a weft to produce a nonwoven fabric, E ') a wide reticulated web and a sheet material It can be manufactured by a step of laminating and.

The step A) of the present invention for producing a material for drawing ultra-high molecular weight polyethylene includes a method for producing a film such as an inflation method, a T-die method, a skive method, etc., and a yarn or film after being dissolved in a solvent. Method, compression molding ultra high molecular weight polyethylene powder in the solid state,
Then, a method of forming into a sheet by roll forming and the like can be mentioned. The compression method may be a batch method, a continuous method, or the like.
The batch type includes slide type, rotary type, etc., and the continuous type compression method is, for example, compression molding while moving the endless belt by sandwiching the ultra high molecular weight polyethylene powder between a pair of vertically facing endless belts. And the like.

B) The step of stretching the stretching material includes
Although not particularly limited, hot-air stretching, cylinder stretching, roll stretching, hot plate stretching and the like can be mentioned. Since stretching of the ultra-high molecular weight polyethylene material is slippery, it is desirable to stretch by applying stretching tension between nip rolls, clover rolls, multi-stage rolls, Nelson rolls and the like.

The stretching temperature is in the range below the melting point of the stretching material, usually 20 to 160 ° C., preferably 60 to 150 ° C.,
More preferably, it is 90 to 145 ° C. The drawing process is 1
It is preferable to carry out not only stages but also multiple stages. In this case, it is desirable to raise the temperature sequentially to perform stretching.

The stretching speed can be appropriately selected depending on the stretching method, the molecular weight of the polymer, the composition ratio, etc., but is usually 1 mm.
˜500 m / min. More specifically, in the case of batch-type stretching, it is 1 to 500 mm / min, preferably 1 to 500 mm / min.
The range is 100 mm / min, more preferably 5 to 50 mm / min. On the other hand, in the case of continuous stretching, it is usually 0.1
˜500 m / min, preferably 1 to 200 m / min, more preferably 10 to 200 m / min. In addition,
The high speed setting is more preferable in consideration of economy.

The higher the draw ratio, the higher the strength of the stretched material that can be obtained. Therefore, it is desirable to increase the draw ratio as much as possible. In order to stretch at a high ratio, it is desirable to perform stretching in a solid state, and examples of these methods include a method in which rolling and tensile stretching are used in combination, a gel stretching method, and the like.

In the present invention, the total stretching ratio, which is the total stretching ratio of rolling and rolling, is 20 times or more, preferably 30 times or more, more preferably 50 times or more, and further preferably 60 to 200 times. desirable.

In the present invention, the stretched material after stretching has a tensile strength of 1.0 GPa or more, preferably 1.5.
GPa or more, more preferably 2 GPa or more, and the tensile elastic modulus is 60 GPa or more, preferably 80 Gpa.
Pa or more, more preferably 120 to 150 GPa.

In the step C) of forming the drawing material into a tape according to the present invention, the drawing material may be cut into a tape shape in advance and used for drawing, or may be cut into a tape shape after drawing.

The step D) of laminating the stretched tape of the present invention on the biaxial or multiaxial yarn laminated nonwoven fabric means that the stretched tape is cross-laminated so that the orientation axes are orthogonal to each other as shown in FIG.
This is a process for obtaining a biaxially or multiaxially yarn-laminated non-woven fabric and heat-sealing the intersections. Similarly, as shown in FIG. 2b or 2c, the yarns are arranged and laminated in the triaxial or tetraaxial directions to form a nonwoven fabric.

The step E) of laminating the laminated non-woven fabric and the sheet material of the present invention is a step of laminating and laminating the laminated non-woven fabric and the sheet material with an adhesive such as hot melt.

C ') a step of producing a wide split web of a stretching material is a method of tapping the stretching material,
To form innumerable minute cuts by any one method of twisting method, sliding rubbing method, mechanical method such as brushing method, air jet method, ultrasonic method, laser method, etc. A rotary mechanical method is particularly preferable. Examples of such rotary mechanical methods include the adoption of various types of splitters such as a tap screw type splitter, a file-shaped rough surface splitter, and a needle roll type splitter. For example, the tap screw type splitter shown in FIG. 3 is usually a pentagonal or hexagonal prism, and is 10 to 40, preferably 15 to 1 inch.
Those with ~ 35 threads are preferred. Further, as the file-like rough surface splitter shown in FIG.
Those disclosed in JP-A No. 1-38980 are preferable. This file-like rough surface splitter is a round file for ironwork or a rough surface similar to this with the surface of the circular cross-section axis having two spiral grooves cut at equal pitches on the surface.

The method for producing the wide reticulated web of the present invention is not particularly limited, but as a typical example, as shown in FIG. 5, a splitter 7 is arranged between the nip rolls 5 and 5'and the nip rolls 6 and 6'and stretched. The working material 20 is moved along the splitter 7 while applying tension, and is brought into sliding contact with a splitter rotating at high speed to split (split) to form a reticulated web.

As shown in FIG. 4, the splitter 7 has a surface 9 of a circular cross-section shaft 8 of the splitter 7 formed into a roughened surface having a file-like shape, and two spiral grooves 10 and 10 'are cut at equal pitches. The grooves 10 and 10 'are formed as square grooves having a depth equal to or higher than the height of the blade on the surface. 6 and 7
4 shows a part of the AA ′ cross section and the axial cross section when the drawing material 20 is split into pieces by bending the drawing material 20 on the splitter of FIG. 2c, which is fitted into the spiral grooves 10 and 10 'of FIG. 2 and is in contact with the perforations on the surface 9, receives a large pressing force due to the concentration of tension, and also receives a force to be pulled in the width direction to split the fibers. Alternatively, it is reticulated as shown in FIG. 2f.

The moving speed of the stretching material is usually from 1 to 100.
It is 0 m / min, preferably 10 to 500 m / min. The rotation speed indicated by the peripheral speed of the splitter can be appropriately selected depending on the physical properties of the stretching material, the moving speed, and the properties of the target reticulated film.
~ 3000 m / min, preferably 50-1000 m / min. The contact angle between the drawing material and the splitter is 3
It is desirable that the angle is 0 to 180 degrees, preferably 60 to 90 degrees. Since the stretching material is slippery, it may be difficult to hold the stretching material at a predetermined speed in the nip rolls installed before and after the splitter, so that a nip roll and a clover roll may be used together, or It is desirable to take slip prevention by using Nelson rolls or by combining these.

In the brushing method and the method using a rotary splitter, the operation is preferably performed by applying tension to the stretching material. The tension is preferably such that the stretching material is deformed by an elongation of 0.1 to 3%, preferably 0.5 to 2%. Further, a controller such as a dancer roll may be installed to keep the tension of the film constant during the split.

The temperature during splitting is usually -20 to +1.
00 ° C., preferably −5 to + 50 ° C., more preferably 0 to 20 ° C. is desirable, and the splitting process may be performed not only in one step but also in multiple steps, and for a material having a large thickness. Alternatively, split processing may be performed from the front and back.

It is also possible to press the drawing material with a rotary baking blade heated above the melting point of the resin and form slits in a zigzag pattern to form a net.

D ') The step of producing a nonwoven fabric by laminating wide split webs in a weft direction is a step of laminating the wide split webs in a weft direction with an adhesive such as hot melt to obtain a nonwoven fabric.

E ') The step of laminating the wide split web of the weft-laid nonwoven fabric and the sheet material is a step of laminating the wide split web of the weft-laid nonwoven fabric and the sheet material with an adhesive and pasting them together.

As the above-mentioned adhesive, high / medium / low density polyethylene, linear low density polyethylene, ultra low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-
Acrylic acid copolymers and ethylene-methacrylic acid copolymers, ethylene-acrylic acid ester copolymers such as ethylene-ethyl acrylate copolymers and ethylene-methacrylic acid ester copolymers, ethylene-maleic acid or its ester copolymers Polymers: polypropylene, propylene-based polymers such as propylene-ethylene copolymers; polyolefins modified with unsaturated carboxylic acids, hot melt adhesives, emulsions and the like.

The sheet material of the present invention includes a weather resistance agent, an antioxidant, an ultraviolet protection agent, and the like, within a range not departing from the gist of the present invention.
You may mix | blend additives, such as a crosslinking agent and a coloring agent.

[0058]

EXAMPLES The present invention will be further described with reference to the following examples.

Examples 1 to 3 (A) Process for producing drawing material (compression roll forming apparatus) Roll: Diameter 500mmφ Face length 300mm 2. Steel belt: wall thickness 0.6mm width 200mm 3. Small diameter roller: Diameter 12mmφ Face length 250mm 4. Pressure plate: length 1000 mm width 200 mm 5. Hydraulic cylinder: Diameter 125 mmφ Using the above device, 1 ultra high molecular weight polyethylene powder having an intrinsic viscosity of 14 dl / g (viscosity average molecular weight of about 2,000,000) was used.
Heated to 30 ℃, the average pressure on the material is about 6kg / c
A sheet having a thickness of 1.1 mm and a width of 100 mm was continuously compression-molded at a speed of 1 mm / min by pressurizing at m ² . Next, this sheet is supplied between a pair of rolls having a diameter of 150 mm, a face length of 300 mm, and a roll distance of 30 μm which rotate in the opposite direction at the same peripheral speed of 1 m / min whose surface temperature is adjusted to 140 ° C. A film having a draw ratio of 7 times was obtained.

(B & C) Rolling process & tape forming process (stretching and sending) 1. Heater: 3 preheating metal rolls, diameter 250mmφ, face length 200mm 1 drawing metal roll, diameter 125mmφ, face length 200mm Circulating the heat medium oil inside the roll. 2. Cooling metal rolls: 3 rolls, diameter 250mmφ, face length 200mm Water circulates inside the rolls. 3. Nip roll Inlet side: 200mmφ Silicon rubber roll nips with two metal rolls for preheating.

Outlet side: 200 mmφ silicon rubber roll is nipped against two cooling metal rolls.

The rolled sheet is slittered to a width of 20 mm.
Was cut into a tape shape, and this was stretch-stretched using the stretching device. The tensile stretching was repeated 3 times under the following conditions. The obtained tape has a width of 6.5 mm and a thickness of 60 μ.
m, and the total draw ratio of the pressure and the draw was 105 times.

Number of times of stretching Metal roll temperature (° C.) Nip roll peripheral speed (m / min) Stretching ratio For preheating Stretching Inlet side Outlet side (times) 1 135 140 1 4 4 2 140 145 4 10 5 2.5 3 140 140 150 10 15 1.5 Total 15 times (D) Yarn laminated non-woven fabric manufacturing process Biaxially, triaxially and axially in which the stretched tapes are laminated so that the orientation axes intersect and the intersections are bonded with a hot melt adhesive. A laminated non-woven fabric of four-axis yarns was prepared and wound into a raw fabric.

(E) Lightweight / super-strength sheet making process The yarn laminated non-woven fabric is unwound from the original roll of the biaxial, triaxial and tetraaxial yarn laminated non-woven fabrics described above, and polyurethane adhesive is applied to both sides of the yarn laminated non-woven fabric. To bond a polyvinyl chloride resin sheet to create a super strong sheet,
The evaluation results of the super strong sheet are shown below.

As the polyvinyl chloride resin sheet, a sheet of 65 μm which has been subjected to a flame retardant treatment with an antimony oxide flame retardant was used.

Example 4 (C ') Process for producing split web The stretched tape of Example 1 was split by a splitter under tension with a speed difference of 1.2% between nip rolls according to the split method shown in FIG. , Created a wide split web. The conditions are as follows.

Film speed: Inlet side roll 20 m / min Outlet side roll 20.24 m / min Splitter: Hexagonal bar edge provided with 32 thread / inch tap screw-like protrusions (maximum diameter 25 mmφ) Contact angle: 90 Degree Rotational speed: 800 rpm (Surface speed 62.8 m / min) Sliding ratio: 3.14 (Splitter rotation speed / Film speed) (D ') Manufacturing process of laminated non-woven fabric composed of split web In this way, a wide split web-woven-woven laminated non-woven fabric was prepared by laminating as described above and adhering the intersections thereof with a hot melt adhesive, and the obtained nonwoven fabric was wound. (E ') Lightweight / ultra-strong sheet making process A wide split web / weft laminated non-woven fabric is unwound from the raw material of the above wide split web / woven laminated non-woven fabric, and a polyvinyl chloride resin is applied to both sides of this non-woven fabric via polyurethane adhesives. The sheets were pasted together to prepare a super-strong sheet, and the evaluation results of the sheet are shown in Table 1.

[0068]

[Table 1]

[0069]

EFFECTS OF THE INVENTION The lightweight / ultra-strong sheet of the present invention has a structure utilizing the flatness of ultra-high molecular weight polyethylene ultra-stretched tape and reticulated web. It has rupture resistance against a blade, cement debris, metal debris, etc. of an ultra-stretched body, is evaluated to be thin, is inexpensive, flexible, and is excellent in handling and workability.

When the lightweight, super-strong sheet of the present invention was used for protection such as concrete crushing work, it was possible to achieve the purpose of protection without being damaged by scattered concrete fragments. However, if the strength of the yarns constituting the sheet of the present invention is 1.0 GPa or less in the case of split yarns, reticulated webs, flat yarns, monofilament yarns or multifilament yarns, the damage as a protective sheet is severe and the practicality is high. Was few.

The triaxial laminate (pitch interval of 5 mm) of the present invention (FIG. 2b) was dipped in polyvinyl chloride plastisol and dried while blowing hot air to give 1-2.
The sheet could have a hole with mm holes.

[Brief description of drawings]

FIG. 1 is a perspective view of a super-strong sheet of the present invention.

FIG. 2 (a) is a schematic view of a biaxial yarn-laminated nonwoven fabric made of an ultra-high molecular weight polyethylene ultra-rolled tape. (B) Similarly, it is a schematic array diagram of a triaxial yarn laminated nonwoven fabric. (C) Similarly, it is an array diagram of a 4-axis yarn laminated nonwoven fabric. (D) A schematic view of a weft-laid nonwoven fabric of ultra-high molecular weight polyethylene wide reticulated web. (E) Similarly, it is a schematic diagram of another weft-laid nonwoven fabric. (F) A schematic view of another laminated weft nonwoven fabric. (G) Similarly, it is a schematic view of another weft-laid nonwoven fabric.

FIG. 3 is a schematic diagram of a tap screw splitter.

FIG. 4 is a schematic view of a file-like rough surface splitter.

FIG. 5 is a main schematic view of a mesh web manufacturing process.

FIG. 6 is a view showing a contact state between the file-like rough surface splitter of FIG. 4 and a stretching material.

7 is a cross-sectional view of the file-like rough surface splitter of FIG.

[Explanation of symbols]

1 Lightweight / super-strength sheet 2 Yarn laminated non-woven fabric or wide-weave mesh web weft laminated non-woven fabric 3,4 Sheet material 5,5 'Entrance side nip roll 6,6' Exit side nip roll 7 Splitter 8 Shaft 9 Surface 10, 10 'Groove 20 Rolling Material

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuhiko Kurihara 3-11-5-1002 Takashimadaira, Itabashi-ku, Tokyo

Claims (4)

[Claims] 1. A biaxial or multiaxial yarn laminated non-woven fabric and a broad reticulated web made of a tape having an ultimate viscosity of 5 dl / g or more and an ultrahigh molecular weight polyethylene having a tensile strength of at least 1.0 GPa in a decalin solution measurement at 135 ° C. A lightweight, super-strong sheet comprising a laminated structure of at least two layers of at least one kind of stretched material selected from a warp-weft laminated nonwoven fabric and a sheet material. 2. The lightweight / super-strength sheet according to claim 1, wherein the sheet material is a non-combustible or flame-retardant sheet. 3. The yarn laminated non-woven fabric and the web weft laminated non-woven fabric according to claim 1 or 2, wherein the laminated structure has a porosity of 30% or more and a sheet material of 5 m.
A protective sheet having a large number of fine holes of m or less. 4. The lightweight / ultra-strong sheet according to claim 1 or 2, wherein the weight of the sheet is 300 per square meter.
A protective sheet characterized by being g or less.