Polyethylene terephthalate hook-and-loop fastener

Abstract

To provide a hook-and-loop fastener whose constituent yarns are all recyclable PET yarns, that has no back coat resin on a back side of a textile for fixing looped engagement elements to a textile base fabric, and that although multifilament yarns constituting the looped engagement elements are rigid PET yarns, has flexibility, soft texture and extremely high engagement force.SOLUTION: In a hook-and-loop fastener including a plurality of looped engagement elements made of PET-based multifilament yarns rising from a surface of a textile made of the PET-based multifilament yarns, the PET-based hook-and-loop fastener is characterized in that a cross-sectional shape of each filament constituting the multifilament yarn constituting the looped engagement element has three or more projections radially projecting from a central part, and each projection has a thin root portion and a bulged head portion roundly spread at the tip thereof.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a recyclable hook-and-loop fastener having woven loop-shaped engaging elements made of polyethylene terephthalate (hereinafter abbreviated as PET)-based yarns, a manufacturing method thereof, and a textile product to which such a hook-and-loop fastener is attached. In particular, the present invention relates to a woven hook-and-loop fastener having loop-shaped engaging elements, in which the warp and weft yarns constituting the woven fabric, and the yarns for the loop-shaped engaging elements are all PET-based yarns, there is no backcoat resin layer on the back surface of the woven fabric for fixing the loop-shaped engaging elements to the woven fabric base fabric, and the PET-based multifilament yarns constituting the loop-shaped engaging elements are made of rigid PET-based polyester yarns, yet the woven hook-and-loop fastener is soft, gentle to the touch, and has extremely high engaging strength. [Background technology]

[0002] In recent years, textile products made of PET-based fibers have been widely used as textile products in the fields of clothing, shoes, gloves, textile goods, etc., as well as in the fields of furniture and interiors such as bedding, chairs, sofas, curtains, etc., in the fields of transportation and carrying such as fixing belts, fastening belts, storage bags, etc., in the fields of civil engineering and construction such as protective cloths and ropes, and in the fields of agriculture, forestry, and fisheries such as binding strings and light-shielding sheets, etc. From the viewpoint of environmental issues, a recycling system is being recommended in which such PET-based textile products are collected after use, melted into pellets, and remolded to be used as new textile products or molding materials.

[0003] Hook-and-loop fasteners are also often used as textile products in the fields of clothing, shoes, gloves, textile goods, etc., as well as in the above-mentioned furniture, transportation and conveyance, civil engineering and construction, agriculture, forestry and fisheries, etc., and when these textile products are made of recyclable PET fibers, if the hook-and-loop fasteners attached to these textile products are made of PET, they will be valued in the market because they can be recycled together with the textile product without having to be removed from the textile product when the textile product is recycled.

[0004] As a hook-and-loop fastener to be attached to these textile products, a combination of a so-called woven hook fastener having a plurality of hook-shaped engaging elements made of monofilament yarn on the surface of a woven base fabric, and a so-called woven loop fastener having a plurality of loop-shaped engaging elements made of multifilament yarn on the surface of a woven base fabric that can engage with the hook-shaped engaging elements, is widely used because there is little damage to the engaging elements and little decrease in engaging force even when the engaging and peeling are repeated.

[0005] Conventionally, such woven hook-and-loop fasteners have generally been made from nylon or polyolefin fibers. In the case of these woven hook-and-loop fasteners, a polyurethane or acrylic adhesive known as a back coat resin is applied to the back surface of the woven base fabric to prevent the hook-like or loop-like engaging elements present on the surface from being pulled out of the woven base fabric when the fastener is released from the engagement. However, since these nylon or polyolefin threads and back coat resins are not PET-based, conventional woven hook-and-loop fasteners cannot be recycled.

[0006] Patent Document 1 describes a woven fabric hook-and-loop fastener in which PET-based yarns are used as the yarns constituting the woven base fabric and the engaging elements and which does not require a backcoat resin layer, in which the warp yarns, weft yarns and engaging element yarns constituting the hook-and-loop fastener are all made of PET-based yarns, the weft yarns are made of heat-fusible PET-based fibers and the engaging element yarns are fixed to the woven fabric by fusing the heat-fusible fibers, resulting in a woven fabric hook-and-loop fastener which does not require a backcoat resin.

[0007] Such woven hook-and-loop fasteners made of PET-based yarns and having no backcoat resin can be recycled, but on the other hand, PET-based yarns are stiffer than nylon-based or polyolefin-based yarns, and hook-and-loop fasteners having loop-shaped engaging elements in particular are used on surfaces that come into contact with the skin, so they are required to be gentle to the touch.However, hook-and-loop fasteners having loop-shaped engaging elements made of PET-based yarns have inferior feel to the touch because the loop-shaped engaging elements are stiff, and are not necessarily suitable for applications requiring a soft feel, such as clothing, shoes, gloves, and miscellaneous goods.

[0008] As a woven hook-and-loop fastener that solves the problems resulting from the stiffness of such PET-based threads, Patent Document 2 proposes a woven hook-and-loop fastener in which the PET-based threads used for the loop-shaped engaging elements in the invention of Patent Document 1 are replaced with polybutylene terephthalate (hereinafter abbreviated as PBT)-based threads.

[0009] It is true that PBT resin is more flexible than PET resin, so it can solve the problem of PET yarn being hard to the touch. However, because PBT yarn is made from a different resin than PET, it cannot be included in the PET recycling system and must be removed from the textile product if it is to be recycled. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. WO2005 / 122817 [Patent Document 2] JP 2013-244139 A Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention provides a woven hook-and-loop fastener having loop-shaped engaging elements, in which the warp and weft yarns constituting the woven fabric, and also the yarns for the loop-shaped engaging elements, are all made of recyclable PET-based yarns, there is no backcoat resin on the back surface of the woven fabric for fixing the loop-shaped engaging elements to the woven fabric base, and the PET-based multifilament yarns constituting the loop-shaped engaging elements are flexible, gentle to the touch, and have extremely high engaging strength, despite being made of rigid PET-based yarns. [Means for solving the problem]

[0012] That is, the present invention relates to a hook-and-loop fastener having a plurality of loop-shaped engaging elements made of PET multifilament yarns standing on the surface of a fabric made of PET multifilament yarns, the cross-sectional shape of the filaments constituting the multifilament yarns constituting the loop-shaped engaging elements has three or more protrusions protruding radially from a center, and each protrusion has a thin base and a round, expanding swollen head at the tip. The multifilament yarn constituting the loop-shaped engaging element is a multifilament yarn in which 25 to 72 filaments of 4 to 12 decitex are bundled together. This is a PET-based hook-and-loop fastener characterized by the above.

[0013] and Preferably, the number of the protrusions is four, the angle between the protrusion directions of adjacent protrusions is a right angle, the width of the narrowest point at the base of the protrusions is 0.6 to 0.9 times the width of the bulging point of the swollen head, the protrusion length of the protrusions is 0.25 to 0.40 times the diameter of the smallest circumscribing circle in the cross section of the filament, and the depth of the recess between adjacent protrusions is 0.20 to 0.35 times the diameter of the smallest circumscribing circle in the cross section of the filament.

[0014] And preferably, in the above-mentioned PET-based hook-and-loop fastener, a woven fabric having PET-based multifilament yarns as warp yarns and PET-based heat-bondable multifilament yarns as weft yarns is used as a base fabric, and PET-based multifilament yarns are woven into the base fabric parallel to the warp yarns as yarns for loop-shaped engaging elements, and a plurality of loop-shaped engaging elements are formed from the yarns for loop-shaped engaging elements on the surface of the base fabric and stand up from the surface of the base fabric, and the bases of the engaging elements are fixed to the base fabric by a molten solidified heat-bonding component of the heat-bondable multifilament yarns, and the multifilament yarns constituting the loop-shaped engaging elements have a soft twist with a twist number of 20 to 200 T / m.

[0015] In the present invention, it is preferable that in addition to the loop-shaped engaging elements, a plurality of hook-shaped engaging elements made of PET-based monofilament yarn are present side by side on the surface of the above-mentioned woven fabric, or that a plurality of hook-shaped engaging elements made of the same monofilament yarn are present on the back surface of the woven fabric.

[0016] The present invention provides a multifilament yarn for a loop-shaped engaging element, the multifilament yarn being made of polyethylene terephthalate filaments having a cross-sectional shape that uses polyethylene terephthalate multifilament yarn as a warp yarn, polyethylene terephthalate heat-fusible multifilament yarn as a weft yarn, the multifilament yarn being made of polyethylene terephthalate filaments having three or more protruding parts radially protruding from a center, each protruding part having a thin base part and a round, expanding swollen head part at its tip, The multifilament yarn constituting the loop-shaped engaging element yarn is a multifilament yarn in which 25 to 72 filaments of 4 to 12 decitex are bundled together, This method for producing a polyethylene terephthalate-based hook-and-loop fastener comprises weaving a fabric having a plurality of loop-shaped threads for engagement elements raised from the surface thereof by weaving threads for loop-shaped engagement elements parallel to the warp threads, and heating the fabric to fix the bases of the loops to the fabric by the molten and solidified heat-fusible component of the heat-fusible multifilament threads.

[0017] In the above-mentioned manufacturing method, it is preferable that the multifilament yarn for the loop-shaped engaging element is manufactured by a method in which PET polyester is melt-spun from a spinneret, the spun yarn is once cooled to a temperature below the glass transition point of the polyester, and then, without bundling or winding, the yarn is made to travel through a heating zone, heated to a temperature above the glass transition point, stretched, and then wound at a take-up speed of 3000 m / min or more (hereinafter, this may be referred to as a CR method). be .

[0018] Furthermore, the present invention relates to a case where the above-mentioned PET-based hook-and-loop fastener is attached to a textile product made of PET-based fibers, and also relates to a method for recycling the textile product while the polyethylene terephthalate-based textile product is still attached. Effect of the Invention

[0019] In the present invention, the warp and weft yarns constituting the woven fabric, as well as the yarns for the loop-shaped engaging elements, are all recyclable PET-based yarns, and the bases of the loop-shaped engaging elements are fixed to the base fabric by the molten solid of the heat-fusible component of the heat-fusible multifilament yarn made of PET-based polyester used as the weft yarn, so that the back surface of the woven fabric does not require a backcoat resin that would prevent recycling, as in conventional woven fabric-based hook-and-loop fasteners. Therefore, the woven fabric-based hook-and-loop fastener having the loop-shaped engaging elements of the present invention can be recycled while still attached to the PET-based textile product, eliminating the need for a process of separating the hook-and-loop fastener members, and thus allowing the recycling system to operate efficiently.

[0020] In the present invention, the multifilament yarn constituting the loop-shaped engaging element is a multifilament yarn made of filaments having the special cross-sectional shape as described above, and therefore has the advantages of being flexible, gentle to the touch, and having extremely high engaging strength, despite being a rigid PET-based yarn.

[0021] It is not entirely clear why such a cross-sectional shape results in a gentle feel and high engagement strength, but since the effects of the present invention cannot be obtained if the filament has a normal cross-sectional shape such as a circle, triangle, square, pentagon, flat, or dog-bone shape, it is believed that the multiple large protrusions on the filament surface make the filament act as if it were a bundle of thin filaments, resulting in significantly improved stiffness of the filament and a softer feel to the touch, and that near the base of the loop-shaped engagement element, the large protrusions and the recesses between them become entangled with the protrusions and recesses of adjacent filaments, compensating for the problem of low engagement strength caused by each filament acting as a bundle of thin filaments.

[0022] Furthermore, in the present invention, the multifilament yarn constituting the loop-shaped engaging element is preferably a multifilament yarn consisting of 25 to 72 filaments of 4 to 12 decitex as described above, but considering that the multifilament yarn constituting the loop-shaped engaging element of the conventional PET-based hook-and-loop fastener is a multifilament yarn consisting of 5 to 20 filaments of 25 to 40 decitex as used in the above patent document, it can be said that the multifilament yarn used in the present invention is a bundle of many extremely thin filaments. In this way, since the multifilament yarn constituting the loop-shaped engaging element is a bundle of many extremely thin filaments, the touch of the obtained hook-and-loop fastener becomes even softer and the engaging strength is further improved.

[0023] Generally, in woven hook-and-loop fasteners, when a multifilament yarn consisting of multiple bundles of thin filaments is used as the multifilament yarn constituting the loop-shaped engaging elements, the resulting hook-and-loop fastener has a soft feel to the touch, but on the other hand, the engaging strength is significantly reduced, and further, repeated engaging and peeling causes the filaments constituting the loop-shaped engaging elements to gradually break, resulting in a sudden decrease in engaging strength. However, such problems with engaging strength are eliminated or alleviated by using a multifilament yarn consisting of filaments having a cross-sectional shape as specified in the present invention.

[0024] Furthermore, in the present invention, it is preferable to use a PET-based multifilament yarn produced by the special spinning and drawing method known as the CR method. When a multifilament yarn produced by this method is used, a hook-and-loop fastener having loop-shaped engaging elements that are even gentler to the touch can be obtained due to a further synergistic effect in accordance with the cross-sectional shape and fineness of the filaments. [Brief description of the drawings]

[0025] [Figure 1] 1 shows a cross-sectional shape of one example of a filament constituting a PET-based multifilament yarn used in a loop-shaped engaging element of a PET-based surface fastener of the present invention. [Diagram 2] 3 shows the cross-sectional shape of another example of a filament constituting a PET-based multifilament yarn used in the loop-shaped engaging element of the PET-based surface fastener of the present invention. [Diagram 3] 1 shows the cross-sectional shape (round shape) of a filament constituting a PET-based multifilament yarn used in a loop-shaped engaging element of a conventional PET-based hook-and-loop fastener. [Figure 4] 1 shows the cross-sectional shape (triangular) of an example of a filament not according to the present invention. [Diagram 5] 1 shows the cross-sectional shape (square) of another example of a filament not according to the present invention. [Figure 6] 1 shows a cross-sectional shape (dog-bone type) of another example of a filament not according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Next, the PET-based surface fastener of the present invention and its manufacturing method will be described in detail. The PET-based surface fastener of the present invention may be any of a loop surface fastener having a plurality of loop-shaped engaging elements on the surface of a woven base fabric, a hook-and-loop coexisting type surface fastener having both a plurality of hook-shaped engaging elements and a plurality of loop-shaped engaging elements on the surface of a woven base fabric, and a single-sided hook-and-single-sided loop surface fastener having a plurality of loop-shaped engaging elements on the surface of a woven base fabric and a plurality of hook-shaped engaging elements on the back surface of the woven base fabric.

[0027] Among these, the loop surface fastener is mainly formed from multifilament yarns for loop-shaped engaging elements, warp yarns and weft yarns. Also, a hook-and-loop coexisting type surface fastener in which hook-shaped engaging elements and loop-shaped engaging elements are coexisting on the same surface, and a one-sided hook-and-opposed loop surface fastener are mainly formed from monofilament yarns for hook-shaped engaging elements, multifilament yarns for loop-shaped engaging elements, warp yarns and weft yarns. And, these surface fasteners may have other yarns woven into them as necessary within the scope of the invention.

[0028] The warp threads, weft threads and threads for the engaging elements must all be composed substantially of PET-based polymers because they do not become wavy (a condition in which the base fabric surface of the hook-and-loop fastener moves up and down irregularly and does not form a horizontal surface) due to heat or water / moisture absorption, the threads can be firmly bonded to each other by heat fusion, the engaging elements are not likely to fall over and are not likely to break even if they are repeatedly engaged and disengaged, and they can be recycled.

[0029] The PET polymer is a polyester mainly composed of ethylene terephthalate units, and is a polymer obtained mainly by a condensation reaction of terephthalic acid and ethylene glycol. Polymer units other than terephthalic acid and ethylene glycol may be added as long as they do not interfere with recycling. Recycled PET polymers may also be used. Furthermore, small amounts of other polymers may be added to the polyester.

[0030] Preferably, the warp yarns other than the weft yarn and the yarns for the engaging elements are formed from PET homopolymer. In any case, it is preferable that the main component of the yarn is a PET-based polyester having a melting point that does not melt at the heat treatment temperature for fusing the sheath component of the core-sheath type heat-fusible multifilament yarn constituting the weft yarn described later. In addition, the PET-based multifilament yarn may have other filaments aligned as necessary within a range that does not prevent recycling.

[0031] The thickness of the multifilament yarn constituting the warp is preferably a multifilament yarn consisting of 20 to 60 filaments and having a total decitex of 100 to 300 decitex, and more preferably a multifilament yarn consisting of 24 to 48 filaments and having a total decitex of 150 to 280 decitex.

[0032] In terms of the fixing effect of the engaging elements, it is preferable that the warp yarns undergo heat shrinkage under the conditions for fusing the heat-fusible multifilament yarns of the weft yarns, and specifically, the dry heat shrinkage rate at 180°C is preferably 4 to 20%. Regarding the dry heat shrinkage rate, polyester fiber manufacturers sell yarns with various values, and it is sufficient to select and use a yarn with an appropriate dry heat shrinkage rate from these. In addition, a commercially available PET multifilament yarn can be appropriately heat-treated to obtain a yarn with a desired dry heat shrinkage rate.

[0033] The thickness of the multifilament yarn constituting the weft is preferably a multifilament yarn consisting of 10 to 72 filaments and having a total decitex of 80 to 300 decitex, and more preferably a multifilament yarn consisting of 18 to 56 filaments and having a total decitex of 90 to 260 decitex.

[0034] The weft yarn contains a heat-fusible filament. A typical example of the heat-fusible filament used is a core-sheath type heat-fusible filament in which the sheath component is the heat-fusible component. Since the weft yarn contains a heat-fusible filament, the thread for the engaging element can be firmly fixed to the woven fabric base, and it is not necessary to apply a polyurethane or acrylic backcoat resin to the back surface of the hook-and-loop fastener base to prevent the thread for the engaging element from being pulled out of the woven fabric base, as in the case of conventional hook-and-loop fasteners.

[0035] The above-mentioned core-sheath type heat-fusible filament is preferably made of a PET-based resin, since the sheath component can be melted to firmly fix the base of the multifilament yarn for the loop-shaped engaging element that is in contact with or located nearby the heat-fusible filament to the base fabric, and this does not interfere with the recycled use of the hook-and-loop fastener.For example, there is included a PET-based fiber having a core-sheath type cross section in which the core component does not melt under heat treatment conditions, but the sheath component melts.

[0036] Specifically, a representative example is a multifilament yarn made of a sheath-core type PET filament having a core component of a PET homopolymer and a sheath component of a copolymerized PET, the melting point or softening point of which is significantly lowered by copolymerizing, for example, 20 to 30 mol % of a copolymerization component such as isophthalic acid or adipic acid. The melting point or softening point of the sheath component is 120 to 210°C, and is preferably 20 to 120°C lower than the melting points of the warp yarn, the core component, the multifilament yarn for the loop-shaped engaging element, or the monofilament yarn for the hook-shaped engaging element. The cross-sectional shape of the filaments constituting the sheath-core type heat-fusible multifilament yarn may be a concentric sheath-core type, an eccentric sheath-core type, or an eccentric sheath-core type that appears to be a bimetal-like laminated shape at first glance. Furthermore, it may be a single-core sheath-core type or a multi-core sheath-core type, and a multifilament yarn made of filaments having a single-core sheath-core cross-sectional shape is particularly preferable.

[0037] Furthermore, the ratio of the sheath-core heat-fusible filaments in the multifilament yarn constituting the weft is preferably in the case where the entire weft is substantially made of sheath-core heat-fusible filaments, that is, where the weft is a multifilament yarn made of sheath-core heat-fusible filaments, because both the yarn for the loop-shaped engaging element and the yarn for the hook-shaped engaging element are firmly fixed to the base fabric. The weight ratio of the core component to the sheath component is preferably in the range of 85:15 to 40:60, and more preferably in the range of 80:20 to 60:40.

[0038] Furthermore, in order to firmly fix both the yarn for the loop-shaped engaging element and the yarn for the hook-shaped engaging element to the base fabric, it is preferable that the heat-fusible filament used as the weft yarn heat-fusible and the filament itself heat-shrinks to fasten the bases of the loop-shaped engaging element and the hook-shaped engaging element from both sides, and for this purpose, it is preferable that the heat-fusible filament used as the weft yarn is one that produces a large heat shrinkage under the heat treatment conditions. Specifically, a filament having a dry heat shrinkage rate at 180°C of 8 to 30% is preferably used, and a multifilament yarn made of a filament having a dry heat shrinkage rate of 10 to 25% is particularly preferable.

[0039] What is important in the present invention is that the multifilament yarn constituting the loop-shaped engaging element is made of a PET filament having a cross-sectional shape with three or more protrusions radially protruding from a center, each of which has a thin base and a round, expanding swollen head at its tip. If the cross-sectional shape of the filament is round, elliptical, oval, triangular, or rectangular, or if there are protrusions but the number is less than three, for example, if it is dog-bone shaped, a satisfactory high engaging strength and gentle touch cannot be obtained.

[0040] Preferably, the number of protrusions is three or four, and particularly preferably, the number of protrusions is four, with adjacent protrusions forming a right angle with respect to the protrusion direction, as shown in Figure 1. Each protrusion has the same size and shape as shown in Figures 1 and 2, and is present on the filament surface at equal intervals in cross section, i.e., each protrusion radially protrudes at equal intervals from the center.

[0041] Figure 2 shows the case where there are three protrusions. Even in this case, superior results are obtained compared to cases where the cross-sectional shape is round (Figure 3), triangular (Figure 4), square (Figure 5), or a dog-bone shape with two protrusions (Figure 6). However, the effect is slightly inferior to the case where there are four protrusions (Figure 1).

[0042] In addition, each protrusion must have a thin base and a round, expanding swollen head at the tip, as shown in Figures 1 and 2. This shape results in the filament having a deep recess and a large swollen head, which results in the protrusions and recesses of adjacent filaments intertwining with each other, resulting in high engagement strength and high engagement / peel durability.

[0043] In the present invention, the angle between adjacent protrusions in the protruding direction being a right angle refers to the angle represented by Q in Figure 1. This does not mean that the angle in the protruding direction is 90 degrees in the strict sense, but rather that it may deviate slightly from 90 degrees, for example, within about 90 degrees plus or minus 20 degrees.

[0044] In terms of engagement strength, it is preferable that the width of the narrowest part of the base of the protrusion (W shown in FIG. 1) is 1 ) is the width of the most bulging part of the bulging head (W shown in Figure 1). 2 ), the protrusion length of the protrusion (H in FIG. 1: the distance from the narrowest point of the root of the protrusion to the tip of the protrusion) is 0.25 to 0.40 times the diameter of the smallest circumscribing circle in the cross section of the filament (D in FIG. 1), and the depth of the recess formed by two adjacent protrusions (d in FIG. 1: the distance from the deepest part of the recess to the smallest circumscribing circle) is 0.20 to 0.35 times the diameter of the smallest circumscribing circle in the cross section of the filament (D in FIG. 1). These dimensional ratios are the same in the case of four protrusions as shown in FIG. 1 and in the case of three or five protrusions as shown in FIG. 2. The above dimensions are the average values ​​of 20 points arbitrarily selected from the cross sections of 10 arbitrarily selected filaments.

[0045] Furthermore, the multifilament yarn constituting the loop-shaped engaging element is preferably a multifilament yarn in which 25 to 72 filaments of 4 to 12 decitex are bundled together as described above. When the filament is 4 decitex or more or the number of bundled filaments is 25 or more, a higher engaging strength is likely to be obtained, and when the filament is 12 decitex or less or the number of bundled filaments is 72 or less, the touch becomes good, the hook-shaped engaging element easily enters the loop of the loop-shaped engaging element, and a very high engaging strength is likely to be obtained. More preferably, the multifilament yarn is a multifilament yarn in which 30 to 64 filaments of 5 to 11 decitex are bundled together, and most preferably, the multifilament yarn is a multifilament yarn in which 36 to 60 filaments of 6 to 10 decitex are bundled together.

[0046] In the present invention, as described above, it is preferable that the multifilament yarn constituting the loop-shaped engaging element is a yarn in which each filament is thinner and the number of bundles is greater than that of the yarn for the loop-shaped engaging element used in general hook-and-loop fasteners, but if such a multifilament yarn in which multiple thin filaments are bundled is used as the loop-shaped engaging element, single yarn breakage may occur during the manufacturing stage of the hook-and-loop fastener, or the loop-shaped engaging element may come apart, and the filaments constituting the loop-shaped engaging element may be cut one by one due to repeated engagement and peeling. In order to alleviate this, it is preferable to give a loose twist with a twist number of 20 to 200 T / m to the multifilament yarn constituting the loop-shaped engaging element.

[0047] In conventional loop hook-and-loop fasteners, the multifilament yarn that constitutes the loop-shaped engaging elements is not twisted, but rather the multifilament yarn is allowed to unravel, and in some cases the surface of the loop hook-and-loop fastener is raised with card clothing or the like to make it easier to engage with the hook-shaped engaging elements. Considering this, it must be said that the present invention, which imparts a twist to the yarn for the loop-shaped engaging elements, deviates from conventional common sense.

[0048] In addition, in terms of the fixing effect of the engaging element, it is preferable that the multifilament yarn for the loop-shaped engaging element undergoes thermal shrinkage under the conditions for fusing the heat-fusible filaments of the weft yarn, similar to the warp yarn, and specifically that the dry heat shrinkage rate at 180°C is 8 to 25%.

[0049] Furthermore, in the present invention, it is preferable to use a PET multifilament yarn produced by the above-mentioned special spinning method called the CR method as the multifilament yarn for the loop-shaped engaging element. By using a PET multifilament yarn produced by such a special method, the feel of the loop surface of the obtained hook-and-loop fastener is further improved.

[0050] Conventionally, a typical method for producing a PET multifilament yarn is to melt-spin a PET polyester from a spinneret, pass it through a pair of rollers, and temporarily wind the undrawn yarn (UDY) on a winder, and then draw the wound undrawn yarn (UDY) between a pair of rollers operating at different speeds to obtain a drawn multifilament yarn (FOY). Other methods include a method in which the undrawn yarn spun from the spinneret is continuously drawn between rollers without being wound, that is, a method in which the spinning step and the drawing step are directly connected to draw the yarn in a single step to produce a multifilament yarn (SDY), and a method in which the spun yarn is not drawn between a pair of rollers, but is drawn all at once before being cooled, and then directly wound at a high speed of 5000 m / min or more to produce a multifilament yarn (DSY).

[0051] However, in the case of PET multifilament yarns obtained by these conventional methods, the PET multifilament yarns generally have to be rigid because the yarns are forcibly drawn. In contrast, when a multifilament yarn is produced by melt-spinning PET polyester from a spinneret as a yarn for loop-shaped engaging elements, cooling the spun yarn to a temperature below the glass transition point of the polyester, and then running it through a heating zone without bundling or winding it, heating it to a temperature above the glass transition point, drawing heat treatment, and then winding it up at a take-up speed of 3000 m / min or more, as in the present invention, the drawing is performed in the spinning zone and in a region continuous therewith, so that the spinning process is responsible for part of the drawing, and therefore the drawing is performed without strain during drawing, and as a result, the resulting PET multifilament yarn is flexible. Therefore, when the PET multifilament yarn produced by such a special method is used, a hook-and-loop fastener having loop-shaped engaging elements that are even more gentle to the touch can be obtained, in accordance with the effect of the cross-sectional shape of the filaments and the effect of their thinness. In the present invention, the spinneret temperature is preferably in the range of 280 to 300°C and the spinning speed is preferably 4000 m / min in order to enable easy stretching during stretching, and it is preferable to run the polyester through a heating zone, heat the polyester to a temperature above the glass transition point, and then wind the polyester at a take-up speed of 3000 m / min or more in order to obtain uniform filament and high tenacity. Also, it is preferable to heat the polyester at a temperature 100°C higher than the glass transition point of the polyester in order to improve thermal stability. If necessary, small amounts of pigments such as titanium oxide, dyes, various stabilizers, other resins, and the like may be added to the multifilament yarn for the loop-shaped engaging element.

[0052] In the present invention, when the target hook-and-loop type hook-and-loop fastener is the above-mentioned hook-and-loop parallel type hook-and-loop single-sided hook-and-opposite-side hook-and-loop fastener, in addition to the above-mentioned multifilament yarn for the loop-like engaging element, the PET monofilament yarn for the hook-like engaging element is also woven into the woven base fabric, and is woven into the woven base fabric parallel to the warp yarn in the same manner as the loop-like engaging element.

[0053] The thickness of the PET monofilament yarn for the hook-shaped engaging element is preferably 0.12 to 0.23 mm in diameter in terms of hook shape retention, and more preferably 0.14 to 0.21 mm in diameter. In order to increase the engaging force, the cross-sectional shape of the monofilament may be an irregular cross-sectional shape, typically a polygonal shape such as a triangle or a square. In terms of the fixing effect of the engaging element, it is preferable that such a PET monofilament yarn for the hook-shaped engaging element undergoes heat shrinkage under the conditions for fusing the heat-fusible fiber of the weft yarn, similar to the warp yarn, and specifically, that the dry heat shrinkage at 180°C is 10 to 25%.

[0054] First, a woven fabric for a hook-and-loop fastener is woven from the above-mentioned warp yarns, weft yarns, multifilament yarns for loop-shaped engaging elements, and, in some cases, monofilament yarns for hook-shaped engaging elements. The weaving structure of the woven fabric is preferably a plain weave in which the multifilament yarns for loop-shaped engaging elements and the monofilament yarns for hook-shaped engaging elements are part of the warp yarns, and these engaging element yarns are woven in parallel with the warp yarns and rise from the surface of the woven fabric base fabric midway through the weave, and in the case of a loop hook-and-loop fastener, it is preferable that they form loops without crossing the warp yarns.

[0055] In the case of a hook-and-loop parallel type fastener or a hook-and-loop fastener with one side hook and the other side loop, it is preferable that the hook-shaped engaging element has a weave structure in which it jumps over one to three warp threads while forming a loop and slips between the warp threads, and that the loop-shaped engaging element has a weave structure in which it jumps over one warp thread while forming a loop, because this makes it possible to efficiently cut one side of the loop for the hook-shaped engaging element and also makes it easy for the hook-shaped engaging element and the loop-shaped engaging element to engage with each other.

[0056] The weave density of the warp yarns is preferably 35 to 80 threads / cm after heat treatment, and the weave density of the weft yarns is preferably 12 to 30 threads / cm after heat treatment, since these threads can firmly fix the base of the engaging elements to the base fabric.Furthermore, the weight ratio of the weft yarns is preferably 15 to 40% of the total weight of the yarns for the hook-shaped engaging elements or the yarns for the loop-shaped engaging elements, the warp yarns, and the weft yarns that constitute the surface fastener, for the same reasons.

[0057] The number of threads of the multifilament yarn for the loop-shaped engaging element and the monofilament yarn for the hook-shaped engaging element is preferably about 2 to 8 threads per 20 warp threads (including the multifilament yarn for the loop-shaped engaging element or the monofilament yarn for the hook-shaped engaging element) in terms of the engaging force. In the case of a hook-and-loop side-by-side hook type surface fastener or a one-side hook / opposite side loop surface fastener, the total number of threads of the multifilament yarn for the loop-shaped engaging element and the monofilament yarn for the hook-shaped engaging element is preferably 2 to 8 threads per 20 warp threads (including the multifilament yarn for the loop-shaped engaging element and the monofilament yarn for the hook-shaped engaging element) for the same reason, and the ratio of the number of threads of the multifilament yarn for the loop-shaped engaging element to the monofilament yarn for the hook-shaped engaging element is preferably in the range of 40:60 to 60:40 for the same reason.

[0058] The thus obtained woven fabric for hook-and-loop fastener is then heat-treated. This heat treatment melts the sheath component of the core-sheath type heat-fusible fiber constituting the weft yarn, and at the same time heat-shrinks the warp yarn, the yarn for the engaging element, and the weft yarn, thereby firmly fixing the multifilament yarn for the loop-shaped engaging element and the monofilament yarn for the hook-shaped engaging element to the woven fabric base. At this time, it is preferable to run the woven fabric for hook-and-loop fastener through the heat treatment furnace without applying too much tension so that the fabric can shrink sufficiently while running through the heat treatment furnace.

[0059] This heat treatment fixes the threads for the engaging elements to the woven base fabric, eliminating the need for the application of a backcoat resin liquid and the drying process of the resin liquid that was previously required with woven hook-and-loop fasteners. This prevents problems such as the inability to recycle due to the backcoat resin, problems with the working environment associated with applying a backcoat resin liquid, and performance problems such as loss of flexibility, breathability, and liquid permeability of the hook-and-loop fastener. Furthermore, the heat during the heat treatment makes the loop-shaped engaging element have a uniform shape with a natural spread in the loop shape. In the case of a hook-shaped engaging element, the loop shape of the hook-shaped engaging element is fixed, and even after one leg of the loop for the hook-shaped engaging element is later cut to form a hook-shaped engaging element, the hook shape is maintained and sufficient engagement strength is obtained.

[0060] The temperature for the heat treatment is generally 150 to 250°C, which is a temperature at which the heat-fusible fibers constituting the weft yarn melt or soften but the other yarns do not melt, and at which the multifilament yarn for the loop-shaped engaging element is fixed into a loop shape with a natural spread, more preferably in the range of 175 to 230°C, and even more preferably in the range of 190 to 220°C.

[0061] Next, in the case where the hook-and-loop fastener is a hook-and-loop parallel type hook-and-loop fastener on one side, after cooling the hook-and-loop fastener fabric, one leg side of the loop for the hook-like engaging element protruding from its surface is cut to form the hook-like engaging element.

[0062] In the hook-and-loop fastener of the present invention, the height of the loop-shaped engaging elements is preferably 1.9 to 3.0 mm from the surface of the woven fabric base, and the height of the hook-shaped engaging elements is preferably 1.2 to 2.1 mm from the surface of the woven fabric base, in terms of engaging force and resistance to collapse of the engaging elements. The density of the loop-shaped engaging elements in the loop fastener, and the total density of the hook-shaped engaging elements and the loop-shaped engaging elements in the hook-and-loop coexisting type fastener and the one-sided hook-and-opposed loop fastener, are 35 to 140 pieces / cm, based on the area of ​​the woven fabric base where the engaging elements are present and after heat shrinkage. 2 , 35~90 pieces / cm 2 In the hook-and-loop coexisting type surface fastener and the one-side hook / opposite-side loop surface fastener, the ratio of the number of hook-shaped engaging elements to the number of loop-shaped engaging elements is preferably in the range of 40:60 to 60:40.

[0063] The loop fastener, hook-and-loop coexisting type fastener, or one-sided hook-and-opposed loop fastener of the present invention can be used in fields of application where conventional general woven fabric fasteners are used, particularly in fields where recycling is required, such as shoes, bags, hats, gloves, etc., as well as clothing, blood pressure monitors, supporters, packing bands, binding tapes, various toys, fixing of sheets for civil engineering and construction, fixing of various panels and wall materials, fixing of electrical parts, storage boxes and packing cases that can be assembled and disassembled, small items, curtains, chairs, sofas, beds, etc., and is particularly suitable for fields where the hook-and-loop fastener is attached to PET fabrics or sheets by sewing, such as clothing, shoes, bags, hats, gloves, supporters, etc. The sewing thread used in this case is preferably a thread made of polyethylene terephthalate fiber.

[0064] The present invention will be described in more detail below with reference to examples. In the examples, the engagement force of the hook-and-loop fastener was measured in accordance with JIS L 3416. In the examples and comparative examples, a hook-and-loop fastener A8693Y (manufactured by Kuraray Fastening Co., Ltd.) was used as the mating hook-and-loop fastener when the hook-and-loop fasteners in the examples and comparative examples were loop hook-and-loop fasteners, and the same hook-and-loop fastener was used when the hook-and-loop fasteners in the examples and comparative examples were hook-and-loop fasteners.

[0065] Example 1 The following yarns were prepared as the warp and weft yarns constituting the woven base fabric of the loop surface fastener and the multifilament yarns for the loop-shaped engaging elements. [Warp] Multifilament yarn made of polyethylene terephthalate with a melting point of 260°C Total decitex and filament count: 167 dtex and 30 filaments Dry heat shrinkage at 180℃: 16%

[0066] [Weft yarn (multifilament heat-sealed yarn made of core-sheath composite fiber)] Core component: Polyethylene terephthalate (melting point: 260°C) Sheath component: Polyethylene terephthalate copolymerized with 25 mol% isophthalic acid (Softening point: 190℃) ·Core-sheath ratio (weight ratio): 70:30 Total decitex and filament count: 24 at 110 dtex Dry heat shrinkage at 180℃: 17%

[0067] [Multifilament yarn for loop-shaped engagement elements] It is made of polyethylene terephthalate. When the cross section of the filament is photographed with a scanning electron microscope, the cross section shape is the same as that in Figure 1, with four protrusions protruding radially from the center, the angle between the protrusions in the direction of protrusion is right angles to the adjacent protrusions, each protrusion has a thin base and a rounded, expanding head at the end, and the W of each filament 1 W 2 The shape is 0.8 times D, H is 0.29 times D, and d is 0.295 times D, and the yarn is a multifilament yarn (FD Spacemaster (registered trademark) CR manufactured by Kuraray Saijo Co., Ltd.) with a twist of 80 T / m and 48 bundles of 7 decitex filaments. The yarn has a melting point of 210°C, a glass transition point of 71°C, and a dry heat shrinkage of 8.9% at 180°C.

[0068] The manufacturing method used was the CR method described above. Specifically, PET was melt-spun from a spinneret, and then cooling air at a temperature of 25°C was blown sideways onto the spun yarn at a speed of 0.5 m / min to cool the yarn to 55°C. Without bundling or winding, the yarn was passed through a tube heater (internal temperature 200°C) 1.0 m long, with an inlet diameter of 5 mm and an outlet diameter of 10 mm, located 1.2 m below the spinneret, and stretched within the heater. The yarn emerging from the heater was oiled, and then wound around two rollers at a take-up speed of 4,500 m / min.

[0069] [Manufacturing of loop fasteners] Using the above warp yarns, weft yarns and multifilament yarns for loop-shaped engaging elements, a plain weave was used as the weaving structure, and the weaving density (after heat shrinkage treatment) was 55 warp yarns / cm and 21 weft yarns / cm. The multifilament yarns for loop-shaped engaging elements were woven parallel to the warp yarns without crossing them at a ratio of 1 for every 4 warp yarns, and after the 5 weft yarns were allowed to float and sink, loops were formed on the woven base fabric.

[0070] The tape for loop hook-and-loop fastener woven under the above conditions was subjected to heat treatment by running it through a heat treatment furnace for 50 seconds at 215°C, a temperature at which only the sheath component of the weft yarn is thermally melted and the warp yarn, the multifilament yarn for loop engaging element, and the core component of the weft yarn are not thermally melted, and the weft yarn, the weft yarn, and the multifilament yarn for loop-shaped engaging element were shrunk. As a result, the tape shrunk by 12% in the weft direction and the sheath component was melted to fuse the neighboring yarns. The obtained woven fabric was cooled, and the loop hook-and-loop fastener was wound up. The process from weaving the hook-and-loop fastener fabric to the heat treatment process was carried out continuously without winding in between.

[0071] The density of the loop-shaped engaging elements in the obtained fabric for loop hook-and-loop fasteners was 42 pieces / cm 2 The height of the loop-shaped engaging elements from the surface of the woven fabric base was 2.2 mm. The threads constituting the hook-and-loop fastener were shrunk by the heat treatment process, and became thicker by about 10%. Ten evaluators were then asked to evaluate the feel of the surface of the resulting loop hook-and-loop fastener where the loop-shaped engaging elements were located, and all of the evaluators rated it as being extremely soft and gentle to the touch, something that was hard to imagine coming from a hook-and-loop fastener made of PET fiber.

[0072] Furthermore, when the engagement strength of this loop hook-and-loop fastener was measured, the initial shear strength was 18.2N / cm 2 After 100 engagement and release cycles, the shear strength was 11.4N / cm 2 The initial peel strength was 2.18 N / cm, and the peel strength after 100 repeated engagement and peeling cycles was 1.65 N / cm, demonstrating that the adhesive had extremely excellent engagement strength. This loop hook-and-loop fastener was attached to a shoe upper tightening belt made of PET fiber using PET sewing thread. It was well received by shoe manufacturers because the hook-and-loop fastener can be removed from the belt at the time of disposal and recycled without the need for sorting.

[0073] Comparative Example 1 In the above-mentioned Example 1, the multifilament yarn for the loop-shaped engaging element was a PET multifilament yarn having a twist number of 80 T / m and consisting of 48 bundles of 7 decitex filaments, the cross section of which is circular as shown in Fig. 3, and the dry heat shrinkage rate at 180°C was 8.8%. The manufacturing method of the multifilament yarn was the same CR method as in Example 1. And the manufacturing method of the loop hook-and-loop fastener was the same as in Example 1.

[0074] The resulting loop hook-and-loop fastener had a surface with loop-shaped engaging elements that felt much softer to the touch than a conventional PET loop hook-and-loop fastener, but all of the evaluators rated it as being inferior to that of Example 1. Furthermore, when the engaging strength of this loop hook-and-loop fastener was measured, the initial shear strength was 12.0 N / cm 2 After 100 engagement and release cycles, the shear strength was 10.9N / cm 2 The initial peel strength was 1.32 N / cm, and the peel strength after 100 repeated engagement / peel cycles was 1.06 N / cm, and the engaging force was also inferior to that of Example 1. This loop hook-and-loop fastener was attached to a shoe upper tightening belt made of PET fiber using PET sewing thread, as in Example 1. Although the hook-and-loop fastener could be recycled without being removed from the belt, it was evaluated as being inferior in terms of feel against the skin and as a result was more restricted in its application to the target shoes than Example 1.

[0075] Comparative Example 2 In the above-mentioned Example 1, the multifilament yarn for the loop-shaped engaging element was a multifilament yarn made of PET, which was a bundle of eight 38 decitex filaments having a circular cross-sectional shape and a dry heat shrinkage rate of 8.7% at 180°C. The manufacturing method for the multifilament yarn was the same CR method as in Example 1. And the manufacturing method for the loop hook-and-loop fastener was the same as in Example 1.

[0076] The surface of the obtained loop surface fastener where the loop-shaped engaging elements were present was extremely hard to the touch, and all of the evaluators rated it as being far inferior to that of Example 1. Furthermore, when the engaging strength of this loop surface fastener was measured, the initial shear strength was 10.9 N / cm 2 After 100 engagement and release cycles, the shear strength was 10.8N / cm 2 The initial peel strength was 1.10 N / cm, and the peel strength after 100 repeated engagement / peel operations was 1.05 N / cm, which was inferior in terms of engagement force as in Comparative Example 1, and was significantly inferior in peel strength in particular. This loop hook-and-loop fastener was evaluated by a shoe manufacturer as being completely unsuitable for use as a belt for fastening the upper of a shoe, due to the poor feel of its surface.

[0077] Example 2 In the above-mentioned Example 1, a loop hook-and-loop fastener was produced by the same method as in Example 1, using a PET fiber (manufacturing method was the above-mentioned CR method) with three protrusions having a cross-sectional shape as shown in FIG. 2 as the multifilament yarn for a loop-shaped engaging element. The thickness and number of bundled filaments constituting the multifilament yarn for a loop-shaped engaging element used, as well as the number of twists, dry heat shrinkage rate and manufacturing method were the same as those of the multifilament yarn for a loop-shaped engaging element in Example 1, and when the cross section of the filament constituting the yarn for a loop-shaped engaging element was observed with a scanning electron microscope, it was found that each protrusion has a thin base portion and a round, expanding head portion at the tip, as shown in FIG. 2, and the width of each filament was 100 mm. 1 W 2 0.65 times, H was 0.28 times, and d was 0.29 times. The density of the loop engaging elements in the obtained fabric for loop surface fasteners and the height of the loop engaging elements from the surface of the woven fabric base were also the same as those in Example 1.

[0078] Although the feel of the surface of the obtained loop hook-and-loop fastener where the loop-shaped engaging elements were present was slightly inferior to that of Example 1, it was soft and gentle to the touch, and all ten evaluators rated it as being extremely soft and gentle to the touch compared to conventional types of hook-and-loop fasteners such as Comparative Example 2. Furthermore, when the engagement strength of this loop hook-and-loop fastener was measured, the initial shear strength was 15.8N / cm 2 After 100 engagement and release cycles, the shear strength was 11.1N / cm 2 The initial peel strength was 1.66 N / cm, and the peel strength after 100 repeated engagement and peeling was 1.33 N / cm, indicating that the adhesive had excellent engagement strength. This loop hook-and-loop fastener was attached to a shoe upper tightening belt made of PET fiber using PET sewing thread, as in Example 1. As with Example 1, the hook-and-loop fastener could be removed from the belt when discarding it and recycled without the need for sorting, and this was well received by shoe manufacturers.

[0079] Comparative Example 3 In the above-mentioned Example 1, the multifilament yarn for the loop-shaped engaging element was a multifilament yarn made of PET, which had a twist number of 80 T / m and was composed of 48 bundles of 7 decitex filaments having a rectangular cross section as shown in Fig. 5, and had a dry heat shrinkage rate of 8.6% at 180°C. The manufacturing method for the multifilament yarn was the same CR method as in Example 1. The manufacturing method for the loop hook-and-loop fastener was also the same as in Example 1.

[0080] The obtained loop surface fastener was evaluated as being slightly gentler on the skin on the surface where the loop engaging elements were present than the loop surface fastener of Comparative Example 1, but was far inferior to those of Examples 1 and 2. Furthermore, when the engaging strength of this loop surface fastener was measured, the initial shear strength was 11.1 N / cm 2 After 100 engagement and release cycles, the shear strength was 10.4N / cm 2 The initial peel strength was 1.22 N / cm, and the peel strength after 100 repeated engagement / peel cycles was 1.04 N / cm, and the engaging force was also inferior to that of Example 1. When this loop hook-and-loop fastener was used to fasten the wrist of gloves made of PET fiber, it was evaluated as being inferior to Example 1 in terms of feel to the skin.

[0081] Comparative Example 4 In the above Example 1, the multifilament yarn for the loop-shaped engaging element was a PET multifilament yarn having a twist number of 80 T / m and consisting of 48 bundles of 7 decitex filaments, the cross section of which has a so-called dog-bone shape with bulging ends as shown in Fig. 6, and a dry heat shrinkage rate of 8.8% at 180°C. The manufacturing method for this multifilament yarn was the same CR method as in Example 1, and the manufacturing method for the loop hook-and-loop fastener was also the same as in Example 1.

[0082] The obtained loop surface fastener had a softer feel on the surface where the loop engaging elements were present than the loop surface fasteners of Comparative Examples 1 and 2, but was inferior to those of Examples 1 and 2. Furthermore, when the engaging strength of this loop surface fastener was measured, the initial shear strength was 11.0 N / cm 2 After 100 engagement and release cycles, the shear strength is 10.2N / cm 2The initial peel strength was 1.16 N / cm, and the peel strength after 100 repeated engagement / peel cycles was 1.02 N / cm, and in terms of engagement strength, it was inferior to those of Examples 1 and 2. This loop hook-and-loop fastener was used for a belt for fastening the upper leather of a shoe, like that of Example 1, and although it was recyclable, it was evaluated to be inferior to those of Examples 1 and 2 in terms of touch.

[0083] Example 3 A hook-and-loop simultaneous type surface fastener was manufactured using the same PET multifilament yarns as in Example 1 as the warp yarns, weft yarns and loop-shaped engaging element yarns, and the following monofilament yarn as the hook-shaped engaging element yarn. A plain weave was used as the weave structure of the hook-and-loop simultaneous type surface fastener, with a weave density (after heat shrinkage treatment) of 55 warp yarns / cm and 20 weft yarns / cm, and the multifilament yarn for loop-shaped engaging element or the monofilament yarn for hook-shaped engaging element was used in a ratio of one for every four warp yarns. In the case of the multifilament yarn for loop-shaped engaging element, a loop was formed on the base fabric so that it crossed one warp yarn after three weft yarns had risen and fallen, and a loop was formed on the base fabric so that it crossed three warp yarns after three weft yarns had risen and fallen, and a loop was formed on the base fabric so that it crossed three warp yarns after three weft yarns had risen and fallen. At that time, the multifilament yarn for the loop-shaped engaging element and the monofilament yarn for the hook-shaped engaging element were woven alternately so that two units each were continuously present.The heat treatment temperature was 205°C. [Monofilament thread for hook-shaped engaging elements] ·Polyethylene terephthalate fiber (melting point: 260℃) ·Fineness: 370dtex (diameter: 0.19mm) Dry heat shrinkage at 180℃: 18%

[0084] The density of the hook-shaped engaging elements of the obtained hook-and-loop parallel surface fastener was 32 pieces / cm 2 The density of the loop-shaped engaging elements is 32 pieces / cm 2Furthermore, the height of the hook-shaped engaging elements from the surface of the base fabric was 1.5 mm, and the height of the loop-shaped engaging elements from the surface of the base fabric was 2.3 mm. The feel of the surface of the resulting hook-and-loop coexisting surface fastener on which the engaging elements were present was evaluated by 10 evaluators in the same manner as in Example 1. All of the evaluators rated the surface as soft and gentle to the touch, despite the presence of the coexisting hook-like engaging elements.

[0085] Furthermore, when the engagement strength of this hook-and-loop type hook-and-loop fastener was measured, the initial shear strength was 18.1N / cm 2 After 100 engagement and release cycles, the shear strength was 11.7N / cm 2 The initial peel strength was 2.14 N / cm, and the peel strength after 100 repeated engagement and peeling was 1.73 N / cm, indicating that the adhesive had excellent engagement strength. This hook-and-loop type hook-and-loop fastener was attached to the end of a supporter made of PET fiber using PET sewing thread, and was well received by users because it could be recycled without having to remove the hook-and-loop fastener from the supporter when it was time to discard it.

[0086] Comparative Example 5 In the above-mentioned Example 3, the multifilament yarn for the loop-shaped engaging element was the same as that in Comparative Example 1, which was a multifilament yarn made of PET having a twist number of 80 T / m and consisting of 48 bundles of 7 decitex filaments having a circular cross section, and having a dry heat shrinkage rate of 8.8% at 180° C. The manufacturing method of the hook-and-loop parallel type surface fastener was the same as that in the above-mentioned Example 3.

[0087] All of the evaluators evaluated that the feel of the surface of the obtained hook-and-loop simultaneous type surface fastener where the loop-shaped engaging elements existed was inferior to that of Example 3. Furthermore, when the engaging strength of this hook-and-loop simultaneous type surface fastener was measured in the same manner as in Example 3, the initial shear strength was 10.7 N / cm 2After 100 engagement and release cycles, the shear strength is 10.5N / cm 2 The initial peel strength was 1.92 N / cm, and the peel strength after 100 repeated engagement / peel cycles was 1.65 N / cm, and the engagement strength was also inferior to that of Example 3. [Explanation of symbols]

[0088] W 1 : Width of the narrow part at the base of the protrusion W 2 : Width of the bulging part of the protruding part H: Projection length of the protrusion D: Diameter of the smallest circumscribed circle in the cross section of the filament d: Depth of the recess formed by two adjacent protrusions

Claims

1. A polyethylene terephthalate-based hook-and-loop fastener having a plurality of loop-shaped engaging elements made of polyethylene terephthalate-based multifilament yarn standing on the surface of a woven fabric made of polyethylene terephthalate-based multifilament yarn, characterized in that the cross-sectional shape of the filaments constituting the multifilament yarn constituting the loop-shaped engaging elements has three or more protrusions protruding radially from a center, each protrusion having a thin base portion and a round, expanding swollen head portion at its tip, and the multifilament yarn constituting the loop-shaped engaging elements is a multifilament yarn consisting of 25 to 72 bundles of 4 to 12 decitex filaments.

2. 2. A polyethylene terephthalate-based surface fastener according to claim 1, wherein the number of protrusions is four, and adjacent protrusions protrude at right angles.

3. 3. The polyethylene terephthalate-based surface fastener according to claim 1, wherein the width of the narrowed portion at the base of the projection is 0.6 to 0.9 times the width of the most expanded portion of the expanded head.

4. 4. The polyethylene terephthalate surface fastener according to claim 1, wherein the length of the protrusions is 0.25 to 0.40 times the diameter of the smallest circumscribing circle in the cross section of the filament.

5. 5. A polyethylene terephthalate surface fastener according to claim 1, wherein the depth of the recess formed between adjacent protrusions is 0.20 to 0.35 times the diameter of the smallest circumscribing circle in the cross section of the filament.

6. 6. The polyethylene terephthalate-based hook-and-loop fastener according to any one of claims 1 to 5, comprising a woven fabric having polyethylene terephthalate-based multifilament yarns as warp yarns and polyethylene terephthalate-based heat-fusible multifilament yarns as weft yarns as a base fabric, polyethylene terephthalate-based multifilament yarns being woven into the base fabric in parallel to the warp yarns as yarns for loop-shaped engaging elements, a plurality of loop-shaped engaging elements formed from the yarns for loop-shaped engaging elements and rising from the surface of the base fabric are present on the surface of the base fabric, and the bases of the engaging elements are fixed to the base fabric by a molten solidified product of the heat-fusible multifilament yarns.

7. 7. A polyethylene terephthalate-based surface fastener according to claim 1, wherein the multifilament yarn constituting the loop-shaped engaging element has a loose twist with a twist number of 20 to 200 T / m.

8. A polyethylene terephthalate-based surface fastener according to any one of claims 1 to 7, wherein in addition to the loop-shaped engaging elements, a plurality of hook-shaped engaging elements made of polyethylene terephthalate-based monofilament yarn are co-present on the surface of the woven fabric, or a plurality of hook-shaped engaging elements made of the same monofilament yarn are present on the back of the woven fabric.

9. A method for producing a polyethylene terephthalate-based hook-and-loop fastener, comprising the steps of: using polyethylene terephthalate-based multifilament yarn as warp yarn; using polyethylene terephthalate-based heat-fusible multifilament yarn as weft yarn; using multifilament yarn made of polyethylene terephthalate-based filaments having a cross-sectional shape having three or more protrusions radially protruding from a center, each protrusion having a thin base and a round, expanding swollen head at its tip; and using as yarns for loop-shaped engaging elements, the multifilament yarns constituting the yarns for loop-shaped engaging elements are multifilament yarns consisting of 25 to 72 bundled filaments of 4 to 12 decitex; weaving the yarns for loop-shaped engaging elements in parallel with the warp yarns; weaving a fabric in which the yarns for loop-shaped engaging elements are raised in a plurality of loops from the surface; and heating the fabric to fix the bases of the loops to the fabric by a molten, solidified product of the heat-fusible multifilament yarns.

10. The method for producing a polyethylene terephthalate-based hook-and-loop fastener according to claim 9 uses a multifilament yarn produced by melt-spinning a polyethylene terephthalate-based polyester from a spinneret as the yarn for the loop-shaped engaging element, cooling the spun yarn to a temperature below the glass transition point of the polyester, and then, without focusing or winding, running the yarn through a heating zone to a temperature above the glass transition point, subjecting it to a stretching heat treatment, and then winding it up at a take-up speed of 3000 m / min or more.

11. A polyethylene terephthalate-based textile product comprising a polyethylene terephthalate-based fiber and a surface fastener according to any one of claims 1 to 8 attached to the textile product.

12. A method for recycling textile products, the method being carried out while the polyethylene terephthalate textile product according to claim 11 is still attached.

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