JP7614579B2 - Flame-retardant hook-and-loop fastener material - Google Patents

Description

The present invention relates to a hook-and-loop fastener material, and more particularly to a hook-and-loop fastener material having excellent flame retardancy and texture.

Hook-and-loop fastener materials are generally used widely in clothing applications, but are also increasingly being used as components for interior materials of houses, vehicles, etc. Various laws and regulations stipulate the required flame retardancy and flame resistance for interior materials of public facilities and vehicles, and particularly for interior materials of railway vehicles, a higher level of flame resistance is stipulated.

Because a high level of flame retardancy is required for the interior materials of railway vehicles, inevitably the hook-and-loop fastener materials used as components of the interior materials of railway vehicles are also required to have high flame retardancy. However, in order to increase the flame retardancy of the hook-and-loop fastener material itself, it is necessary to incorporate a large amount of flame retardant into the hook-and-loop fastener material, which tends to result in problems such as a deterioration in the texture of the hook-and-loop fastener material, the flame retardant becoming more likely to fall off, and the flame retardant becoming more likely to bleed.

In order to solve such problems, the present inventors have succeeded in suppressing various problems such as deterioration of texture and bleeding of flame retardants while ensuring high flame retardancy of the entire railway vehicle seat upholstery material through the combined flame retardant action of each layer, by incorporating specific flame retardants into the skin material, adhesive layer, and hook-and-loop fastener material layer, respectively, even if the content of flame retardant in the hook-and-loop fastener material is suppressed to a certain degree, as described in Patent Document 1.

However, in the above-mentioned method, high flame retardancy can be obtained for the entire railway vehicle seat upholstery material only when each layer of the railway vehicle seat upholstery material is limited to a specific configuration, but the flame retardancy is insufficient when considering the hook-and-loop fastener material alone, and when considering expansion to other applications requiring flame retardancy, it is difficult to directly use this hook-and-loop fastener material for other applications, making it poorly versatile.

JP 2020-66414 A

The present invention has been made in consideration of the above circumstances, and its main object is to provide a hook-and-loop fastener material which has excellent flame retardancy and a good texture even when the content of various organic flame retardants is kept to a relatively small amount.

Means to solve the problem

As a result of research conducted by the inventors in order to solve the problems of the present invention, it was found that by using a hook-and-loop fastener material having a knitted base fabric and engaging elements provided on one side of the base fabric, with an organic flame retardant fixed thereto, wherein the base fabric has a warp knit structure in which first warp knitted fabric sections and second warp knitted fabric sections having different wale densities are arranged alternately in stripes parallel to the wale direction, superior effects in terms of flame retardancy and texture can be obtained compared to hook-and-loop fastener materials using a base fabric composed only of a warp knitted fabric of the same wale density.

As a result of further investigations, the inventors have found that by setting the wale density of the first warp knitted structure portion in the range of 14.0 wale/inch or more and 20.0 wale/inch or less and the wale density of the second warp knitted structure portion in the range of 7.0 wale/inch or more and 13.5 wale/inch or less, it is possible to impart better flame retardancy and texture to the hook-and-loop fastener material while maintaining the strength and elasticity of the hook-and-loop fastener material.

Effect of the Invention

The hook-and-loop fastener material of the present invention has excellent flame retardancy, and can be widely used as a hook-and-loop fastener material for applications requiring flame retardancy. Since the base fabric of the hook-and-loop fastener material itself has the effect of enhancing flame retardancy, it is possible to reduce the amount of organic flame retardant contained in the hook-and-loop fastener material, and as a result, it is possible to suppress deterioration of the texture of the hook-and-loop fastener material caused by the flame retardant and the occurrence of bleeding of the flame retardant. In addition, since the texture of the base fabric itself is good, when used as a hook-and-loop fastener material for vehicle seats, for example, it is possible to suppress deterioration of the texture caused by the hook-and-loop fastener material when sitting.

FIG. 2 is a schematic cross-sectional view showing an example of an embodiment of a hook-and-loop fastener material. FIG. 2 is a schematic plan view showing an example of an embodiment of a surface side of a hook-and-loop fastener material on which engaging elements are not provided. 1 is a schematic plan view showing an example of an embodiment of a surface side on which engaging elements of a hook-and-loop fastener material are provided. FIG. Schematic cross-sectional view showing an example of a method of using the hook-and-loop fastener material. Schematic diagram of the test stand and test specimens used in the flammability testing of railway vehicle materials.

The hook-and-loop fastener material 1 of the present invention has a basic structure having a base fabric 2 made of a knitted fabric and an engaging element 5 provided on one side of the base fabric 2, as shown in Figures 1 to 3, and an organic flame retardant is fixed to the base fabric 2 and the engaging element 5. Furthermore, the base fabric 2 of the hook-and-loop fastener material 1 of the present invention has a warp knit structure in which a first warp knit structure portion 3 and a second warp knit structure portion 4 having different wale densities are arranged alternately in parallel stripes in the wale direction. The wale direction refers to the up-down direction in Figures 2 and 3, and the course direction refers to the left-right direction in Figures 2 and 3. Furthermore, a wale refers to a row of loops that are continuous in the wale direction, and a course refers to a row of loops that are lined up in the course direction. Similarly, the wale density refers to the number of wales per unit length in the course direction, and the course density refers to the number of courses per unit length in the wale direction.

When the hook-and-loop fastener material 1 of the present invention is used for a seat covering member 8 of a vehicle or the like, the seat covering member 8 is created by bonding the hook-and-loop fastener material 1 and a skin material 6 together with an adhesive or the like 7, as shown in Figure 4, and the seat covering member 8 can be fixed to the seat by engaging the engaging element 5 of the seat covering member 8 with an engaging object 9, such as the cushioning material of the vehicle seat or another hook-and-loop fastener material provided on the seat.

<<Components of the hook-and-loop fastener material>>
Next, details of the hook-and-loop fastener material and each component of the present invention will be described below.

<Base fabric>
As the base fabric of the hook-and-loop fastener material, it is preferable to use a knitted fabric having a certain degree of elasticity so that the engaging element is firmly fixed between the engaged object and the engaged object, and even if the engaged object is deformed, it can follow the deformation and fit and engage, and it is more preferable to use a knitted fabric that can maintain excellent elongation in the vertical direction, horizontal direction, and bias direction (diagonal direction) as the hook-and-loop fastener material, but it is particularly preferable to use a knitted fabric having a warp knitting structure from the viewpoint of the elasticity and strength of the base fabric. As the knitted fabric having a warp knitting structure, knitted fabrics knitted by various raschel knitting machines, various tricot knitting machines, various Milanese knitting machines, etc. can be used, and it is more preferable to use a knitted fabric knitted by a double raschel knitting machine, although it is not limited to these.

As a result of extensive research by the present inventors to obtain good flame retardancy in the hook-and-loop fastener material of the present invention, it was found that, compared to using a base fabric with a constant knitting density as the base fabric of the hook-and-loop fastener material, a base fabric with an arbitrarily partially changed knitting density tends to provide better flame retardancy. Although the reason for this is unclear, it is thought that by providing a density difference in the knitting structure of the base fabric used in the hook-and-loop fastener material, a suppression effect is exerted on the spread of fire in the hook-and-loop fastener material in flammability tests, etc., which is advantageous in evaluating the flame retardancy.

As a result of further investigations, the inventors have found that if a base fabric having a warp knitted structure in which first warp knitted structure sections and second warp knitted structure sections having different wale densities are arranged alternately in stripes parallel to the wale direction is used as the base fabric for a hook-and-loop fastener material, not only can better flame retardancy be obtained, but a hook-and-loop fastener material can be obtained which has a good texture and excellent elasticity and strength.

The present inventors have further investigated the details of the first warp knitted structure portion and the second warp knitted structure portion having different wale densities, and as a result have obtained the following findings.

The wale density of the first warp knitted structure portion is preferably in the range of 14.0 wale/inch to 20.0 wale/inch, more preferably in the range of 14.0 wale/inch to 18.0 wale/inch. If the wale density of the first warp knitted structure portion is within the above range, the strength, stretchability and texture of the hook-and-loop fastener material can be maintained in a good state, but if it is below the lower limit of the above range, the strength of the hook-and-loop fastener material tends to decrease, and conversely, if it is above the upper limit of the above range, the knitted structure becomes dense, causing the hook-and-loop fastener material to lose flexibility, resulting in a worsening of the texture and a worsening of the stretchability of the hook-and-loop fastener material.

The wale density of the second warp knitted structure portion is preferably in the range of 7.0 wale/inch to 13.5 wale/inch, more preferably in the range of 9.0 wale/inch to 13.5 wale/inch. If the wale density of the second warp knitted structure portion is within the above range, the strength and texture of the hook-and-loop fastener material can be maintained in a good state while increasing the flame retardancy of the hook-and-loop fastener material. However, if the wale density is below the lower limit of the above range, the strength of the hook-and-loop fastener material tends to decrease, and conversely, if the wale density is above the upper limit of the above range, the flame retardancy and texture of the hook-and-loop fastener material tend to deteriorate.

The inventors have confirmed that by setting the wale density of the second warp knitted structure portion within the above range, the combustion of the hook-and-loop fastener material is weakened at the boundary between the first warp knitted structure portion and the second warp knitted structure portion in flammability tests, etc., and it is believed that the structural flame retardant effect of the specific knitting structure in the base fabric portion of the hook-and-loop fastener material improves the flame retardancy of the hook-and-loop fastener material itself, and as a result, the hook-and-loop fastener material of the present invention makes it possible to reduce the content of flame retardant.

As a result of extensive research by the inventors, it has been found that the hook-and-loop fastener material of the present invention exhibits particularly excellent performance in terms of flame retardancy, texture, strength and elasticity when the wale densities of the first warp knitted structure portion and the second warp knitted structure portion of the base fabric both satisfy the preferred ranges described above.

The width of each of the first warp knitted tissue section and each of the second warp knitted tissue section, which are successively arranged in stripes parallel to the wale direction of the base fabric, in the course direction is not particularly limited, but in order to exhibit the structural flame retardant effect of the hook-and-loop fastener material, the width of each of the second warp knitted tissue sections in the course direction is preferably 3 mm or more, more preferably 5 mm or more. On the other hand, as the width of each of the second warp knitted tissue sections in the course direction increases, the strength of the hook-and-loop fastener material tends to become insufficient, so the width of each of the second warp knitted tissue sections in the course direction is preferably 30 mm or less, more preferably 20 mm or less. Similarly, in order to maintain the strength of the hook-and-loop fastener material, the width of each of the first warp knitted tissue sections in the course direction is preferably 10 mm or more, more preferably 15 mm or more. On the other hand, if the course direction width of each first warp knitted structure portion becomes large, it becomes difficult to obtain the structural flame retardant effect of the hook-and-loop fastener material, and elasticity and texture tend to deteriorate, so it is preferable that the course direction width of each first warp knitted structure portion be 100 mm or less, and more preferably 80 mm or less.

Furthermore, from the viewpoint of maintaining the strength of the hook-and-loop fastener material, it is preferable that the course direction width of each of the first warp knitted tissue sections constituting the first warp knitted tissue section is at least one time the course direction width of each of the second warp knitted tissue sections constituting the second warp knitted tissue section, and from the viewpoint of making it easier to obtain the structural flame retardant effect of the hook-and-loop fastener material, it is preferable that the course direction width of each of the first warp knitted tissue sections is no more than five times the course direction width of each of the second warp knitted tissue sections.

The course density of the base fabric is not particularly limited, but is preferably in the range of 14.0 courses/inch to 28.0 courses/inch, and more preferably in the range of 16.0 courses/inch to 26.0 courses/inch. If the course density of the base fabric is within the above range, the strength, texture, stretchability, etc. of the hook-and-loop fastener material can be well maintained, but if it is below the lower limit of the range, the strength of the hook-and-loop fastener material tends to decrease, and if it is above the upper limit of the range, the knit structure becomes dense, which tends to deteriorate the texture and stretchability of the hook-and-loop fastener material.

As the yarn used for the base fabric, it is preferable to use filament yarn from the viewpoint of the strength of the hook-and-loop fastener material, and it is more preferable to use multifilament yarn from the viewpoint of the texture of the hook-and-loop fastener material. The material of the yarn used for the base fabric is not particularly limited, and various synthetic resins can be used, and it is preferable to use polyester resin, polyamide resin, polyolefin resin, etc., and it is more preferable to use polyester resin or polyamide resin from the viewpoint of the flame retardancy, strength, and processability of the hook-and-loop fastener material.

The yarn count used for the base fabric is preferably in the range of 180 dtex to 500 dtex, and more preferably in the range of 200 dtex to 400 dtex. If the yarn count used for the base fabric is within the above range, the strength and texture of the hook-and-loop fastener material are good, but if the yarn count is below the lower limit of the above range, the strength of the hook-and-loop fastener material tends to gradually become insufficient, and conversely, if the yarn count is above the upper limit of the above range, the yarn becomes thicker and the gaps between the meshes decrease, causing the flexibility of the hook-and-loop fastener material to gradually decrease, and as a result, the texture of the hook-and-loop fastener material tends to deteriorate.

<Engagement element>
The shape of the engaging elements of the hook-and-loop fastener material of the present invention is not particularly limited and may be mushroom-shaped, loop-shaped, hook-shaped or other shapes; although there is no particular limitation, it is preferable to use the mushroom shape for applications where engagement strength is required, such as seat covering materials for vehicles, interior materials for automobiles and homes, and where the engagement strength or engaged state must be maintained for a long period of time.

As the thread used for the engaging element, it is preferable to use filament thread from the viewpoint of the strength of the hook-and-loop fastener material, and it is more preferable to use monofilament thread from the viewpoint of ease of processing of the engaging element and ensuring peel strength. The material constituting the thread used for the engaging element is not particularly limited and various synthetic resins can be used, but it is preferable to use various synthetic resins such as polyester resin, polyamide resin, polyolefin resin, etc. In the case of the mushroom-shaped engaging element as described above, it is more preferable to use polypropylene monofilament thread from the viewpoint of ease of thermal processing of the engaging element.

The thread count used for the engaging element is not particularly limited and may be appropriately selected depending on the various required qualities and intended use. From the standpoint of the strength of the engaging element itself, the ability of the hook-and-loop fastener material to follow deformation of the engaged body, and the feel of the hook-and-loop fastener material, it is preferable to use a thread count in the range of 180 dtex to 500 dtex, and it is even more preferable to use a thread count in the range of 200 dtex to 400 dtex.

The density of the engaging elements in the hook-and-loop fastener material of the present invention is not particularly limited, but is preferably in the range of 40 elements/ ^cm2 to 70 elements/ ^cm2 per unit area of the base fabric. If the density of the engaging elements is within the above range, the texture of the hook-and-loop fastener material, the engagement strength between the hook-and-loop fastener material and the engaged body, and the ability of the hook-and-loop fastener material to follow the deformation of the engaged body can be maintained in a good state, but if the density is below the lower limit of the above range, peeling between the hook-and-loop fastener material and the engaged body tends to occur easily, and conversely, if the density is above the upper limit of the above range, the texture of the hook-and-loop fastener material, the ability of the hook-and-loop fastener material to follow the deformation of the engaged body, and the productivity of the hook-and-loop fastener material tend to deteriorate.

<Flame retardants>
As the flame retardant used in the hook-and-loop fastener material of the present invention, it is preferable to use various organic flame retardants from the viewpoint of being able to impart high flame retardancy and being easily fixed to the hook-and-loop fastener material by post-processing. Examples of organic flame retardants include bromine-based flame retardants (aliphatic bromine compounds, aromatic bromine compounds, brominated polymer type, etc.), organic phosphorus-based flame retardants (aliphatic phosphate ester compounds, aromatic phosphate ester compounds, aromatic aliphatic phosphate ester compounds, aromatic phosphate ester amide compounds, halogen-containing phosphate ester compounds, various organic phosphorus- and nitrogen-containing compounds, various organic phosphorus- and bromine-containing compounds and their metal salts, phosphinic acid metal salts, etc.), and nitrogen-based flame retardants (melamine compounds, melamine cyanurate compounds, melamine phosphate compounds, guanidine compounds, guanylsulfamide compounds, etc.), but are not limited thereto, and can be appropriately selected and used according to the intended use and the required quality. In addition, these organic flame retardants may be used alone, or two or more flame retardants may be mixed and used.

The organic flame retardant used in the present invention is preferably one having a melting point of at least 50° C. or higher, and more preferably one having a melting point of at least 80° C. By using an organic flame retardant having such a melting point, stickiness when touching the hook-and-loop fastener material, bleeding of the flame retardant, and the occurrence of various problems due to these are largely eliminated.

Since the hook-and-loop fastener material of the present invention is expected to be used as a component of various interior materials, from the viewpoint of various environmental regulations, it is preferable to use a halogen-free organic flame retardant among the various flame retardants mentioned above, and it is even more preferable to use a halogen-free organic phosphorus-based flame retardant or a nitrogen-based flame retardant.

The method of adhering the flame retardant to the hook-and-loop fastener of the present invention is not particularly limited, but includes a method of impregnating the entire hook-and-loop fastener with a processing liquid containing various organic flame retardants, followed by hot air drying and, if necessary, heat treatment. The temperature and time of the hot air drying and heat treatment are appropriately selected in consideration of the material of the hook-and-loop fastener. By such a method, the organic flame retardant is adhered to the surface of the base fabric and engaging elements constituting the hook-and-loop fastener, and more preferably, the organic flame retardant is firmly adhered to the surface of the thread constituting the base fabric and engaging elements.

The organic flame retardant to be fixed to the hook-and-loop fastener material is preferably contained in a range of 1.0% by mass or more of the entire hook-and-loop fastener material, more preferably in a range of 3.0% by mass or more. If the content of the organic flame retardant in the hook-and-loop fastener material is below the lower limit of the above range, the flame retardant effect tends to be poor. Conversely, the organic flame retardant to be fixed to the hook-and-loop fastener material is preferably contained in a range of 15.0% by mass or less of the entire hook-and-loop fastener material, more preferably in a range of 10.0% by mass or less. If the content of the organic flame retardant in the hook-and-loop fastener material exceeds the upper limit of the above range, the hook-and-loop fastener material becomes hard, which tends to deteriorate the texture, deteriorate various mechanical properties such as elongation and tensile strength, and cause the flame retardant to bleed. If the hook-and-loop fastener material contains the organic flame retardant in a range that satisfies the above upper and lower limits, the effect of imparting flame retardancy to the hook-and-loop fastener material is sufficiently obtained, and at the same time, the texture of the hook-and-loop fastener material is not significantly impaired.

<Hook-and-loop fastener material>
The hook-and-loop fastener material of the present invention comprises at least a base fabric made of knitted fabric and engaging elements provided on one side of the base fabric, with an organic flame retardant adhered thereto. The base fabric further has a warp knit structure in which first warp knitted structure sections and second warp knitted structure sections having different wale densities are arranged alternately in stripes parallel to the wale direction, thereby making it possible to obtain a hook-and-loop fastener material which has excellent flame retardancy and a good texture even when the content of various organic flame retardants is kept relatively small.

Since the hook-and-loop fastener material of the present invention has excellent flame retardancy, it is expected that it will be used primarily as a component for the interior materials of public facilities and vehicles. Furthermore, if it is used as a seat covering material for vehicles, etc., it can be used preferably because it has a good texture that does not detract from the texture of the seat covering material.

In particular, when the hook-and-loop fastener material of the present invention is used as a seat covering material for a vehicle, etc., it is required that the hook-and-loop fastener material be able to follow the deformation of the cushion material to be engaged, which is made of nonwoven fabric, polyurethane foam, etc. As a result of the inventor's investigation into this point of view, it was found that the elongation percentage of the hook-and-loop fastener material (JIS L1096 Method A (cut strip method)) should preferably be in the range of 15% to 50% in both the longitudinal and lateral directions, and further in the range of 30% to 60% in the bias direction.

When engaging the engaging element side of the hook-and-loop fastener with the object to be engaged, the hook-and-loop fastener must be stretched to engage with the curved surface of the object to be engaged, otherwise wrinkles will form on the hook-and-loop fastener. If the stretch rate in the longitudinal and lateral directions is less than 15%, or the stretch rate in the bias direction is less than 30%, the appearance will be poor due to the occurrence of wrinkles, and the engagement will come loose from those parts, resulting not only in poor appearance, but also in problems such as a decrease in the surface strength of the outer material and peeling, due to the wrinkled parts rubbing against other materials.

On the other hand, if the elongation rate of the hook-and-loop fastener material in the longitudinal and lateral directions is greater than 50%, or the elongation rate in the bias direction is greater than 60%, then when it is engaged with the engageable body, it will have sufficient elongation to engage, and will be engaged with the engageable body while stretching it more than necessary.If left as is after engagement, the engaging elements of the hook-and-loop fastener material will not be able to withstand the shrinkage that occurs after engagement with the engageable body, and problems such as poor appearance due to misalignment between the hook-and-loop fastener material and the engageable body caused by shrinkage will occur.

In addition to the above-mentioned elongation, the hook-and-loop fastener material of the present invention is required to have sufficient strength to withstand installation and long-term engagement, since it is handled together with various interior materials. As a result of the inventor's investigation into such a viewpoint, it was found that the tensile strength of the hook-and-loop fastener material (JIS L1096 A method (cut strip method)) is preferably 200 N/inch or more. If the tensile strength of the hook-and-loop fastener material is less than 200 N/inch, the hook-and-loop fastener material cannot withstand installation of the interior materials or long-term engagement, and the hook-and-loop fastener material tends to be largely distorted or broken, resulting in various defects. With regard to the tensile strength, it is preferable that the hook-and-loop fastener material has a tensile strength of 200 N/inch or more in all of the longitudinal, transverse and bias directions.

When the hook-and-loop fastener material of the present invention is used as a seat covering member for a vehicle or the like, it is required that the texture when seated is good. Specifically, if the hook-and-loop fastener material is too hard when a person sits on the seat, the hook-and-loop fastener material will impair the softness of the skin material and cushion material of the seat covering member, causing the person to feel a so-called "foreign body sensation," and the texture when seated tends to be impaired. In order to address such a problem, the present inventors have conducted extensive research and found that the bending hardness of the hook-and-loop fastener material measured by a pure bending tester: KES-FB2-AUTO-A (manufactured by Kato Tech Co., Ltd.) is preferably 0.60 gf·cm ² /cm or less, and more preferably 0.50 gf·cm ² /cm or less. If the bending hardness is greater than 0.60 gf·cm ² /cm, the effect of the hardness of the hook-and-loop fastener material becomes significant when used as a covering member, and the overall texture of the seat covering member for a vehicle or the like tends to be impaired.

The basis weight of the hook-and-loop fastener material of the present invention is not particularly limited, but is preferably from 150 g/ ^m2 to 450 g/ ^m2 , and more preferably from 200 g/ ^m2 to 400 g/ ^m2 . If the basis weight of the hook-and-loop fastener material is within the above range, the hook-and-loop fastener material can have appropriate strength, stretchability, and texture.

The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto.

<Method of manufacturing hook-and-loop fastener material>

The hook-and-loop fastener material used in Example 1 was produced by the following method. A double raschel knitting machine was used to knit two base fabrics using polyester multifilament yarn (280 dtex/48f) with a uniform course density of 24.0 courses/inch, a first warp knitted fabric part with a wale density of 15.5 wale/inch and a second warp knitted fabric part with a wale density of 11.8 wale/inch in parallel stripes in the wale direction, and the width of each of the first warp knitted fabric parts constituting the first warp knitted fabric part was 16.0 mm, and the width of each of the second warp knitted fabric parts constituting the second warp knitted fabric part was 6.5 mm. The two base fabrics were connected by polypropylene monofilament yarn (280 dtex) to produce a green machine. The monofilament yarn was cut at the middle part between the two base fabrics produced, to produce two base fabrics having monofilament yarn protrusions on one side that will later become engagement elements. The tips of the projections of the monofilament yarns of these base fabrics were heated and melted by a gas burner to produce a hook-and-loop fastener having mushroom-shaped engaging elements.

Next, water was added to flame retardant 1 (nitrogen-based flame retardant) shown in Table 1 below, and the flame retardant was homogeneously diluted with water to prepare a flame retardant-containing processing liquid with a solid content of 10%. The entire hook-and-loop fastener material prepared above was immersed in the flame retardant-containing processing liquid and then squeezed with a mangle roll to adjust the amount of flame retardant-containing processing liquid impregnated. The hook-and-loop fastener material was then dried in a hot air dryer at a temperature of 100°C for 5 minutes to fix the flame retardant to the entire hook-and-loop fastener material so that the adhesion amount after drying was 15 g/ ^m2 , thereby producing the hook-and-loop fastener material used in Example 1 of the present invention.

Regarding the knitting structure of the base fabric of the hook-and-loop fastener material of Example 1, the wale density of the first warp knitted structure portion was changed to 16.0 wale/inch, the wale density of the second warp knitted structure portion was changed to 13.1 wale/inch, the width of each of the first warp knitted structure portions constituting the first warp knitted structure portion was changed to 17.0 mm, and the width of each of the second warp knitted structure portions constituting the second warp knitted structure portion was changed to 10.0 mm.Other than that, the hook-and-loop fastener material used in Example 2 was prepared under the same conditions as the hook-and-loop fastener material of Example 1.

The hook-and-loop fastener material used in Example 3 was prepared under the same conditions as the hook-and-loop fastener material of Example 1, except that the flame retardant adhered to the hook-and-loop fastener material was changed to Flame Retardant 2 (organic phosphorus-based flame retardant).

(Comparative Example 1)
The hook-and-loop fastener material used in Comparative Example 1 was prepared under the same conditions as the hook-and-loop fastener material of Example 1, except that the base fabric portion of the hook-and-loop fastener material of Example 1 was changed to a base fabric made of a warp knitted structure using polyester multifilament yarn (280 dtex/48f) with a course density of 24.0 courses/inch and a wale density of 15.0 wale/inch.

(Comparative Example 2)
The hook-and-loop fastener material used in Comparative Example 2 was prepared under the same conditions as the hook-and-loop fastener material of Comparative Example 1, except that the amount of flame retardant 1 adhered after drying was changed to 50 g/m2.

(Comparative Example 3)
The hook-and-loop fastener material used in Comparative Example 3 was prepared under the same conditions as the hook-and-loop fastener material of Comparative Example 1, except that the flame retardant attached to the hook-and-loop fastener material was changed to Flame Retardant 2.

<<Various evaluation methods for hook-and-loop fastener materials>>
The methods for evaluating the surface fastener materials prepared by the above-mentioned method will now be described.

<Evaluation of the flame retardancy of hook-and-loop fastener materials>
One of the objects of the hook-and-loop fastener material of the present invention is to carry out a flammability test for railway vehicle materials established by the Japan Railway Vehicle and Machinery Technology Association, and to have the results satisfy or exceed the standard for the "flame retardant" category of the flammability standard for railway vehicle materials in the Ministerial Ordinance Prescribing Technical Standards for Railways (Article 83, Paragraph 3). Therefore, the flame retardancy of the hook-and-loop fastener material used in the examples of the present invention is evaluated by carrying out a flammability test for railway vehicle materials and judging, based on the results, which category of the flammability standard for railway vehicle materials it falls into.

The test method for the flammability test of railway vehicle materials is as follows: as shown in FIG. 5, a test stand 8 is used, which is composed of a B5 size hook-and-loop fastener specimen 9, which is inclined at 45 degrees from the horizontal plane with the side of the hook-and-loop fastener material that does not have an engaging element facing downward, an iron alcohol container 10 (diameter φ17.5 mm, depth 7.1 mm), and a container receiving stand 11; i) the alcohol container is placed so that the center of the bottom of the alcohol container is 1 inch vertically below the center of the underside of the specimen, 0.5 cc of pure ethyl alcohol is poured into the alcohol container and ignited, ii) the ignition, flame, smoke generation, and flame state of the specimen during alcohol combustion are observed, iii) the residual flame, residual dust, charring, and deformation state of the specimen after the alcohol combustion are investigated, and then iv) it is judged whether or not the specimen satisfies the flammability criteria shown in each category of the flammability standard for railway vehicle materials (Table 2 below), and finally it is judged which category it falls into, thereby making an evaluation.

<Evaluation of the strength of hook-and-loop fastener materials>
For the hook-and-loop fastener material used in the examples of the present invention, the tensile strength (JIS L1096 Method A (cut strip method)) in the longitudinal direction (the wale direction is the longitudinal direction), lateral direction (the course direction is the lateral direction), and bias direction of the hook-and-loop fastener material was measured under the measurement test conditions shown below, and the strength of the hook-and-loop fastener material was evaluated based on the measurement results and in accordance with the evaluation criteria shown below.
(Measurement test conditions)
Size of the test piece when cut: 25 mm x 200 mm
Width of test piece during measurement: 25 mm
Grip interval during measurement: 100 mm
Tensile speed during measurement: 100 mm/min
(Evaluation Criteria)
○: Tensile strength in all directions is 200 N/inch or more. ×: Tensile strength in any direction is less than 200 N/inch.

<Evaluation of the elasticity of hook-and-loop fastener material>
For the hook-and-loop fastener material used in the examples of the present invention, the elongation percentages (JIS L1096 Method A (cut strip method)) in the longitudinal direction (the wale direction is the longitudinal direction), lateral direction (the course direction is the lateral direction), and bias direction of the hook-and-loop fastener material were measured under the measurement test conditions shown below, and the elasticity of the hook-and-loop fastener material was evaluated based on the measurement results and in accordance with the evaluation criteria shown below.
(Measurement test conditions)
Size of the test piece when cut: 25 mm x 200 mm
Width of test piece during measurement: 25 mm
Grip interval during measurement: 100 mm
Tensile speed during measurement: 100 mm/min
(Evaluation Criteria)
◯: The stretch rate in the longitudinal and transverse directions is within the range of 15% to 50%, and the stretch rate in the bias direction is within the range of 30% to 60%.
x: The stretch rate in either the longitudinal or transverse direction is less than 15% or exceeds 50%, or the stretch rate in the bias direction is less than 30% or exceeds 60%.

<Evaluation of the texture of hook-and-loop fastener materials>
For the hook-and-loop fastener material used in the examples of the present invention, the bending hardness in the vertical and horizontal directions was measured under the measurement conditions shown below using a pure bending tester: KES-FB2-AUTO-A (manufactured by Kato Tech Co., Ltd.), and the texture of the hook-and-loop fastener material was evaluated based on the measurement results and in accordance with the evaluation criteria shown below.
(Measurement test conditions)
Size of test piece: 10cm x 10cm
Clamp spacing: 1.0 cm
(Evaluation Criteria)
◯: The bending stiffness in both the longitudinal and transverse directions is 0.50 gf·cm2/cm or less.
. . . The bending hardness in both the longitudinal and transverse directions is 0.60 gf·cm2/cm or less, and at least one of the bending hardnesses is greater than 0.50 gf·cm2/cm.
× . . . At least one of the bending hardness in the longitudinal direction and the transverse direction is greater than 0.60 gf·cm2/cm.

Details of the various hook-and-loop fastener materials used in the examples and comparative examples and the results of the above-mentioned measurements and evaluations performed on the hook-and-loop fastener materials are shown in Table 3 below.

From the results in Table 3, it can be seen that the hook-and-loop fastener materials of Examples 1 to 3, which have a base fabric made of knitted fabric and engaging elements provided on one side of the base fabric and have an organic flame retardant fixed thereto, and in which the base fabric has a warp knit structure in which first warp knitted structure sections and second warp knitted structure sections having different wale densities are arranged alternately in stripes parallel to the wale direction, have good texture, strength and stretchability, and furthermore, even if the content of the organic flame retardant in the hook-and-loop fastener material is a relatively small amount of about 5 to 6 mass%, it is able to meet the criteria for the "flame retardant" category in the flammability standard for railway vehicle materials when subjected to a flammability test for railway vehicle materials. On the other hand, when a knitted fabric consisting of only a warp knitted structure with approximately the same wale density as the first warp knitted structure portion of Examples 1 to 3 was used as the base fabric, as in Comparative Example 1 and Comparative Example 3, even if the content of the organic flame retardant was the same as in Examples 1 to 3, the criteria for the "flame retardant" category in the flammability standard for materials for railway vehicles could not be met, and all were rated as "slow flame retardant", and the evaluation of the texture of the hook-and-loop fastener material was also worse than in Examples 1 to 3. Regarding Comparative Example 2, which is an example in which the content of the organic flame retardant in the hook-and-loop fastener material of Comparative Example 1 was increased to 15.2%, the content of the organic flame retardant in the hook-and-loop fastener material was increased by about three times compared to Example 1, but the criteria for the "flame retardant" category in the flammability standard for materials for railway vehicles was not met, and the evaluation of the "slow flame retardant" category was worse than in Example 1.

According to the present invention, it is possible to provide a hook-and-loop fastener material having excellent flame retardancy and texture, which can be used not only as interior components for houses and vehicles where flame retardancy is particularly required, but also as a hook-and-loop fastener material for other general purposes.

1; hook-and-loop fastener material 2; base fabric 3; first warp knitted sections 3a to 3d; each of the first warp knitted sections 4; second warp knitted sections 4a to 4c; each of the second warp knitted sections 5; engaging element 6; cover material 7; adhesive, etc. 8; seat cover member 9; engaged body (cushion material, hook-and-loop fastener material, etc.)
10; test stand 11; test specimen 12; alcohol container 13; container receiving stand

Claims (13)

The hook-and-loop fastener material has a base fabric made of knitted fabric and engaging elements provided on one side of the base fabric, and has an organic flame retardant fixed thereto, the hook-and-loop fastener material having a warp knit structure in which a first warp knit structure section and a second warp knit structure section having different wale densities are arranged alternately in stripes parallel to the wale direction. 2. The hook-and-loop fastener material according to claim 1, wherein the wale density of the first warp knitted structure portion is in the range of 14.0 wale/inch or more and 20.0 wale/inch or less, and the wale density of the second warp knitted structure portion is in the range of 7.0 wale/inch or more and 13.5 wale/inch or less. A hook-and-loop fastener material as described in either claim 1 or claim 2, wherein the course-direction width of each of the first warp knitted tissue sections constituting the first warp knitted tissue section is in the range of 10 mm or more and 100 mm or less, and the course-direction width of each of the second warp knitted tissue sections constituting the second warp knitted tissue section is in the range of 3 mm or more and 30 mm or less. A hook-and-loop fastener material according to any one of claims 1 to 3, wherein the course-direction width of each first warp-knitted structure portion constituting the first warp-knitted structure portion is in the range of 1.0 to 5.0 times the course-direction width of each second warp-knitted structure portion constituting the second warp-knitted structure portion. 5. The hook-and-loop fastener material according to claim 1, wherein the yarn used for the base fabric is a multifilament yarn having a fineness in the range of 180 dtex or more and 500 dtex or less. 6. The hook-and-loop fastener material according to claim 1, wherein the material of the thread used in the base fabric is a polyester resin or a polyamide resin. 7. The hook-and-loop fastener material according to claim 1, wherein the thread used for the engaging elements is a monofilament thread having a fineness in the range of 180 dtex to 500 dtex. 8. The hook-and-loop fastener material according to claim 1, wherein the course density of the base fabric is in the range of 14.0 courses/inch or more and 28.0 courses/inch or less. 9. The hook-and-loop fastener material according to claim 1, wherein the organic flame retardant is contained in an amount of 15% by mass or less of the entire hook-and-loop fastener material. 10. The hook-and-loop fastener material according to claim 1, wherein the organic flame retardant is a halogen-free organic flame retardant. The hook-and-loop fastener material according to any one of claims 1 to 10, wherein the elongation percentages in the lateral and longitudinal directions of the hook-and-loop fastener material measured by JIS L1096 A method are in the range of 15% or more and 50% or less, and the elongation percentage in the bias direction is in the range of 30% or more and 60% or less. 12. The hook-and-loop fastener material according to claim 1, wherein the tensile strength of the hook-and-loop fastener material in the transverse, longitudinal and bias directions measured according to JIS L1096 Method A is 200 N/inch or more. 13. The hook-and-loop fastener material according to any one of claims 1 to 12, wherein the bending hardness in the longitudinal and transverse directions measured by a pure bending tester (KES-FB2-AUTO-A) is 0.60 gf·cm2/cm or less.

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