JPS6226901B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aromatic polyamide fiber laminate sheet with improved tear strength. Conventionally, one or both sides of a base fabric made of synthetic fiber threads, such as polyester fiber threads or vinylon fiber threads, are coated with synthetic resin, such as polyvinyl chloride, or synthetic rubber, such as polyurethane. Sheets, such as waterproof sheets, are known. Such synthetic fiber laminated sheets are widely used for truck canopies, tent fabrics, and the like. In this case, a woven fabric made of synthetic fiber filament yarn is generally used as the base fabric. However, if this base fabric becomes thin (lightweight), the tensile strength of the resulting laminated sheet becomes unsatisfactory, and if the texture of the base fabric is made dense to prevent this drawback, the resulting laminated sheet may tear. There were problems such as unsatisfactory strength and the tendency to tear the key. Furthermore, when the base fabric is thick, there are problems in that the weight of the resulting laminated sheet becomes excessively large, making it inconvenient to handle, and its tear strength is not very high. Furthermore, the surface of the thick base fabric has large irregularities, and in order to smooth it, a large amount of synthetic resin or synthetic rubber must be used for coating, which has the disadvantage of increasing manufacturing costs. apart from,
This results in disadvantages in that the weight of the resulting laminated sheet increases and its tear strength decreases. In view of the current situation as described above, it has been thought that it is almost impossible to simultaneously satisfy the three requirements of reducing the weight of a laminated sheet, improving its tensile strength, and improving its tear strength. However, in recent years, there has been a strong demand for laminated sheets such as waterproof sheets to be lighter and thinner while maintaining satisfactory tensile strength and tear strength. This has become one of the important issues. One possible way to meet the above demands is to use aromatic polyamide fibers. Aromatic polyamide fibers (for example, Kevlar (trademark) manufactured by DuPont) have a tensile strength of 20 to 25 g/d and an elongation at break of 3 to 5%.
A laminated sheet whose base fabric is a woven fabric made of yarns mainly composed of high-strength aromatic polyamide fibers has excellent tensile strength, and therefore is practically satisfactory even if the base fabric is made lightweight and thin. A laminated sheet having the desired tensile strength can be obtained. However, it has been found that such a laminated sheet has the drawback of being susceptible to key tearing. It is known that the resistance of a laminated sheet to tearing corresponds approximately to its tear strength. Therefore, in order to increase the resistance of an aromatic polyamide fiber laminate sheet to tearing, it is necessary to improve its tear strength. In order to improve the above-mentioned tear strength, the present inventors have already proposed a laminated sheet based on a fabric made of aromatic polyamide fiber threads and different types of fiber threads. However, the heat resistance of the different fiber yarns is inferior to that of the aromatic polyamide fiber yarns, so the heat resistance of the resulting laminated sheet depends on the low heat resistance of the different fiber yarns. For this reason, in the case of laminated sheets containing different types of fiber threads, there has been a problem in that the processing conditions and selection of processing materials are restricted by the low heat resistance of the different types of fiber threads. An object of the present invention is to provide an aromatic polyamide fiber laminate sheet that not only has excellent tear strength but also excellent heat resistance. The above objects are achieved by the present invention. The aromatic polyamide fiber laminate sheet of the present invention comprises aromatic polyamide fiber yarns () having a mixing ratio of 60 to 99% by weight, a tensile strength of 15 to 40 g/d, and a breaking elongation of 1 to 8%. , mixing ratio 40-1% by weight
A base fabric made of a knitted fabric made of aromatic polyamide fiber yarn () having a tensile strength of 10 g/d or less and a breaking elongation of 10% or more, and at least one surface of the base fabric. formed of synthetic resin or
A covering layer made of synthetic rubber is included. In the laminated sheet of the present invention, the low-strength aromatic polyamide fiber yarn () mixed with the high-strength aromatic polyamide fiber yarn () has a tensile strength considerably higher than that of the yarn (). Even if it is small, for example, 1/2 or less, if the elongation at break is 10% or more, for example, 2.5 times or more the elongation at break of the yarn (), surprisingly, it can be obtained. The resulting laminated sheet exhibits extremely high tear strength. The laminated sheet obtained by controlling the mixing ratio of low-strength aromatic polyamide fiber threads () from 1 to 40%, for example, from 1 to 8 fibers per 2.54 cm, has a tensile strength that is practically satisfactory. can be retained. In the laminated sheet of the present invention, the base fabric may be either a knitted fabric or a woven fabric, but in the case of a woven fabric, its warp and/or weft are those mainly composed of aromatic polyamide fiber threads (). It is. This aromatic polyamide fiber thread () is 15~
It has a tensile strength of 40 g/d and a breaking elongation of 1 to 8%, and although there is no particular limitation on its fineness, it is generally preferable to have a fineness of 100 to 1500 deniers. The yarn may be spun yarn, monofilament yarn, multifilament yarn, or tape yarn, but is generally made from filament with a single fiber fineness of 1 to 15 deniers, more preferably 1.5 to 5 deniers. Preferably, it is a multifilament yarn. The aromatic polyamide constituting the aromatic polyamide fiber yarn () and/or () is at least
70 mol% of the following formulas () and (): (-Ar ₁ -CONH)- () and (-Ar ₁ -CONH-Ar ₂ -NHCO)- () [However, Ar ₁ and Ar ₂ are divalent represents an aromatic group, which may be the same or different. ] Preferably, the main repeating group is at least one selected from the following repeating groups. At this time, in the above formulas () and (), the divalent aromatic groups represented by Ar ₁ and Ar ₂ are:

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

[expression] and

[However, A represents -O-, -S-, -SO-, -SO ₂ -, -CO-, -CH ₂ -, or -C(CH ₃ ) ₂ -]

Preferably, it is selected from the group of aromatic residues represented by the following. These aromatic residues may contain inert substituents such as halogens, alkyl groups, nitro groups, and the like. Generally, the aromatic polyamide constituting the yarn () has the following repeating units: Preferably, it has as a main component. In general, the aromatic polyamide constituting the yarn () has the following repeating units: Preferably, it has as a main component. The base fabric used in the laminated sheet of the present invention is preferably made of a woven fabric containing aromatic polyamide fiber threads as a main component in the warp and/or weft. Although there are no particular limitations on the basis weight and structure of this fabric, it generally has a basis weight of 30 to 200 g/m ² and a warp density of 5 to 150 pieces/2.54 cm.
A woven fabric, particularly a plain woven fabric, having a weft density of 5 to 150 pieces/2.54 cm is preferred. Aromatic polyamide fiber yarn () is 10g/d
Tensile strength of preferably 3 to 10 g/d and 10
% or more, preferably 10 to 50%, and the elongation at break is particularly preferably at least 2.5 times the elongation at break of the aromatic polyamide fiber yarn (). The elongation at break of the yarn () is
If it is less than 10% or its tensile strength is 10g/d
In the above cases, the tear strength of the resulting laminated sheet becomes unsatisfactory. The shape of the yarn () may be spun yarn, monofilament yarn, multifilament yarn, or tape yarn, but generally it is composed of filaments with a single fiber fineness of 1 to 15 deniers and has a total fineness of 100 to 15. Preferably a 1500 denier multifilament;
Further, it is preferable that the thickness of the yarn (2) and the thickness of the yarn (2) mixed therewith are approximately equal, thereby making it possible to obtain a laminated sheet having a flat surface. In a base fabric made of a woven fabric, the threads () are inserted between the threads () one by one or in groups of two to five adjacent threads at intervals. At this time, the blending rate of yarn () is 1 to 40%,
Preferably 5 to 20%, especially 1 to 2.54 cm
The number is preferably 8, and more preferably 1 to 5. When the blending rate of yarn () is less than 1%, the tear strength of the resulting laminated sheet will be unsatisfactory. In addition, the blending rate of yarn () is 40
%, the resulting laminated sheet may have an unsatisfactory tensile strength. In particular, when the yarn () has a small total fineness (for example, 100 to 250 deniers), the mixing ratio of the yarn () is 1
% or more, but when the yarn () has a large total fineness (for example, 500 to 1500 deniers), the blending rate of the yarn () is preferably 5.0% or more. Also yarn () and ()
may each be a single yarn, or may be a twisted yarn of two or more single yarns, or may be a drawn yarn. Further, each single yarn may be a non-twisted yarn or a twisted yarn. The yarn ( ) may be twisted together with the yarn ( ), or may be aligned. The woven structure of the base fabric used in the present invention is not particularly limited, but plain weave, oxford weave, leno weave, or other fabrics containing leno threads are generally used. Insertion of threads () between threads () is performed by inserting one thread () or two to five threads () adjacent to each other in parallel.
A group of threads () of a book are each a single thread ()
It is preferable that the fibers are arranged by separating the yarns or groups of 2 to 150 yarns (2 to 150 yarns) that are arranged adjacent to each other in parallel. In the laminated sheet of the present invention, a covering layer made of synthetic resin or synthetic rubber is formed on one side or both sides of the base fabric. The amount of the coating layer can be determined arbitrarily depending on the purpose of the coating and the type of coating material, but in general
Preferably the weight is between 20 and 500 g/ ^m2 , and 50
It is more preferable that it is ~300g/ ^m2 . The synthetic resin and synthetic rubber that form the coating layer can be arbitrarily selected depending on the purpose of the coating, but in general, polyvinyl chloride, ethylene-vinyl acetate copolymer, polyester, polyamide (such as nylon 12) are used for waterproofing. ), polyolefin (polyethylene, polypropylene), polyimide, polyamideimide, polyether, polyketone, thermoplastic polymer such as polysulfone, silicone resin, polyphosphazene and polyurethane, synthetic rubber such as fluorine-containing resin, etc. are used. be able to. The synthetic resin or synthetic rubber forming the coating layer is generally highly elastic and flexible, but thermosetting resins such as phenolic resins, epoxy resins, unsaturated polyester resins,
It may be made of one or more of polyimide resins, triazine resins, melamine resins, bisdiene polymer resins, etc., or it may be a mixture of these and thermoplastic resins. At this time, if a highly heat-resistant synthetic resin such as silicone resin, polyimide resin, polyamide-imide resin, polyphosphite resin, or fluorine-containing resin is used, the overall heat resistance will be improved along with the highly heat-resistant aromatic polyamide fiber base fabric. A laminated sheet with extremely good properties can be obtained. To form the coating layer on the base fabric, a solution or emulsion, sometimes a dispersion, or a film of the desired resin is applied to the desired surface of the base fabric using a conventional impregnation method, adhesion method, or coating method. All you have to do is give it to . Next, the present invention will be further explained by examples. Example: As aromatic polyamide fiber yarn ()
400d/267f Kevlar 29(TM) fiber yarn (cutting strength: 22 g/d, breaking elongation: 4%), and 400d/48f Nomex(TM) fiber (Dupont) yarn (cutting Strength: 5.5 g/d, elongation at break: 20%) were used to weave six types of plain woven fabrics with the following structures by varying the mixing ratio. 400d/1×400d/1/30/25.4mm
×30/25.4 mm threads () were inserted between the threads () at intervals, and the mixing ratio was as shown in Table 1. The obtained plain woven fabric was used as a base fabric, and after scouring and drying it by a conventional method, RTV silicone rubber (Toshiba Silicone Corporation) was applied to the surface as a base coating agent.
A mixture of 10 parts by weight and 1 part by weight of crosslinking agent was coated using a knife coater to give a coating weight of 90 g/m ² . Next, heat this to 140℃
A heating cylinder heated to , and a linear pressure of 10
The sample was passed through a heating calendar consisting of a pressure roll that was pressed at a pressure of Kg/cm, and was kept in contact with the surface of the heating calendar for 45 seconds. A top coat finishing agent having the same composition as the base coat finishing agent was further applied to the obtained base coat layer at a coating amount of about 10 g/m ² to adjust the surface condition, and heat treatment was performed at 180°C. Table 1 shows the tensile strength and tear strength of the obtained laminated sheet.

[Table] As is clear from Table 1, a laminated sheet (sample 6) using a base fabric composed only of threads ()
Both the tensile strength and tear strength of the laminated sheet (sample 5) using a base fabric containing 50% of threads () and yarns () and the tear strength of the laminated sheet using a base fabric composed only of threads () It is clearly inferior to those of the sheet (sample 1). However, yarn ()
When mixed in the yarn () at a mixing rate of 5 to 40% (Samples 2, 3, and 4), surprisingly, the resulting laminated sheets were improved and improved compared to Samples 1, 5, and 6. It exhibited tear strength, and the tensile strength was also practically satisfactory. In addition, the obtained laminated sheets of Samples 2, 3, and 4 according to the present invention are composed of a base fabric with excellent heat resistance and a silicone resin coating layer, so they exhibit excellent heat resistance as a whole, and Since it was thin, it was excellent in practical use as a welding apron, not only in terms of heat resistance but also in workability.

Claims (1)

[Claims] 1. Aromatic polyamide fiber yarn () having a blending ratio of 60 to 99% by weight, a tensile strength of 15 to 40 g/d, and a breaking elongation of 1 to 8%, and a blending ratio of 40%. A base fabric made of a knitted fabric made of ~1% by weight of aromatic polyamide fiber yarn () having a tensile strength of 10 g/d or less and a breaking elongation of 10% or more, and a small amount of the base fabric. 1. An aromatic polyamide fiber laminate sheet comprising: a coating layer formed on one side of the polyamide fibers, and a coating layer made of synthetic resin or synthetic rubber. 2. The base fabric is made of a woven fabric having the yarn () as a main component in the warp and/or weft, and the yarn ()
The longitude and/or latitude is 2.54cm.
The laminated sheet according to claim 1, comprising 1 to 8 said yarns () per sheet. 3 Between the yarns (), one of the yarns ()
Or, groups of 2 to 5 yarns () arranged adjacent to each other are inserted at intervals,
A laminated sheet according to claim 2. 4. The laminated sheet according to claim 1, wherein the elongation at break of the yarn ( ) is 2.5 times or more the elongation at break of the yarn ( ). 5 The yarn () and/or the aromatic polyamide constituting the yarn () has at least 70 mol% of the following formula () and (): (-Ar ₁ --CONH)- () and (-Ar ₁ —CONH—Ar ₂ —NHCO)— () [However, Ar ₁ and Ar ₂ represent divalent aromatic groups, and these may be the same or different. ] The laminate sheet according to claim 1, which has at least one type selected from the following repeating groups. 6 In the above formulas () and (), the divalent aromatic group represented by Ar ₁ is [formula] [formula] [formula] [formula] [formula] [formula] [formula] [formula] and [formula] [However, A is -O-, -S-, -SO-, -SO ₂
-, -CO-, -CH ₂ -, or -C(CH ₃ ) ₂ -] The laminate sheet according to claim 5, which is selected from the group of aromatic residues represented by the following. 7 In the above formulas () and (), the divalent aromatic group represented by Ar ₂ is [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] ] [However, A is -O-, -S-, -SO-, -SO ₂
-, -CO-, -CH ₂ -, or -C(CH ₃ ) ₂ -] The laminate sheet according to claim 5, which is selected from the group of aromatic residues represented by the following. 8. The laminated sheet according to claim 1, wherein the yarn ( ) has a tensile strength of 15 to 30 g/d and a breaking elongation of 1 to 8%. 9 The yarns () and () are each
The laminated sheet according to claim 1, having a fineness of 100 to 1500 deniers. 10. The laminated sheet according to claim 1, wherein the yarns () and () are each a spun yarn, a monofilament yarn, a multifilament yarn, or a tape yarn. 11 The above-mentioned single thread () or a group of 2 to 5 threads () arranged adjacently in parallel each other, or a group of 2 to 5 threads arranged adjacently in parallel 150
The laminated sheet according to claim 1, wherein the laminated sheet is arranged to separate the groups of threads of the book.