Molded hook-and-loop fastener, method for manufacturing same, and hook-and-loop fastener overlapping body

Abstract

Provided are a molded hook-and-loop fastener and a method for manufacturing the same. The molded hook-and-loop fastener (10) has a substrate (11) and hook-type engagement elements (12) protruding from the surface thereof, both the substrate (11) and the hook-type engagement elements (12) being constituted of a cellulose ester resin composition, the cellulose resin composition containinh a cellulose ester and an adipic acid ester-based compound in a weight ratio of 94 / 6 to 55 / 45 of cellulose ester to adipic acid ester-based compound, and the degree of orientation of the substrate (11) in the machine direction being 0.120‒0.390.

Description

Molded hook-and-loop fastener, its manufacturing method, and hook-and-loop fastener stack Related Applications

[0001] This application claims priority from Japanese Patent Application No. 2024-022408, filed on February 16, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a molded hook-and-loop fastener having biodegradability based on ISO 14851, a method for producing the same, and a hook-and-loop fastener stack including the same.

[0003] Hook-and-loop fasteners can fasten hook-type engaging elements and loop-type engaging elements together by utilizing the physical engaging force between them, and are used in a variety of products, including everyday items. Hook-and-loop fasteners with hook-type engaging elements are broadly classified into woven hook-and-loop fasteners that use woven fabric as a base fabric, and molded hook-and-loop fasteners that use resin molded materials as a base material.

[0004] Molded surface fasteners have the advantage of being highly flexible in terms of the shape of the engaging elements that protrude from the substrate, and therefore have the advantage of being able to increase the engaging force. Molded surface fasteners are further broadly classified into injection-molded types and extrusion-molded types.

[0005] In the injection molding type, a molten resin is forced into a cavity and the shape of the cavity is used to form the engaging elements, whereas in the extrusion molding type, a tape-like material comprising a substrate and engaging element rows is first formed by extrusion molding, and after multiple slits are made in the engaging element rows, the tape-like material is stretched to form the engaging elements.

[0006] Molded hook-and-loop fasteners can be manufactured by molding resins in this way. Plastic products are indispensable in daily life because they are lightweight and inexpensive, but at the same time, there is a growing demand for biodegradable resins that put less strain on the natural environment when discarded.

[0007] For example, Patent Document 1 (JP-A-11-181261) discloses a biodegradable resin molded article that is made from a resin material in which starch is added to a biodegradable resin whose main component is a polybutylene succinate-based and / or polyethylene adipate-based aliphatic polyester.

[0008] Furthermore, Patent Document 2 (WO 2020 / 196722) discloses a hook-shaped molded surface fastener having a substrate and a large number of hook-shaped engaging elements protruding from its surface, wherein the substrate and the hook-shaped engaging elements are both made of a resin mixture having polybutylene succinate as a continuous phase and a specific starch and polyvinyl alcohol as dispersed phases.

[0009] On the other hand, cellulose-based compounds are known to have excellent biodegradability, and Patent Document 3 (WO 2020 / 218271) discloses a cellulose ester composition containing a cellulose ester as component (A), an adipic acid ester compound as component (B), and a citrate ester compound as component (C).

[0010] Japanese Patent Application Laid-Open No. 11-181261 International Publication No. 2020 / 196722 International Publication No. 2020 / 218271

[0011] In Patent Document 1 and Patent Document 2, biodegradability is ensured by using aliphatic polyesters. However, Patent Document 1 assumes biodegradability after composting, while Patent Document 2 targets biodegradability in soil maintained at 40°C. Therefore, there is room for further improvement in terms of biodegradability.

[0012] In Patent Document 3, a cellulose ester composition having excellent biodegradability is obtained, but this document does not describe at all how to produce a hook-and-loop fastener.

[0013] Therefore, an object of the present disclosure is to provide a molded hook-and-loop fastener that is compatible with biodegradability based on ISO 14851 and the engaging force required of a hook-and-loop fastener.

[0014] As a result of investigations aimed at solving such problems, the present inventors discovered that when a molded surface fastener made of a cellulose ester resin composition is manufactured while controlling the orientation degree in the machine direction of the substrate of the molded surface fastener, the resulting molded surface fastener has the engaging force required of a surface fastener and can also have improved biodegradability based on ISO 14851, and thus completed the present invention.

[0015] That is, the present invention can be configured in the following aspects: [Aspect 1] A molded surface fastener having a substrate having a first surface and a second surface, and hook-type engaging elements protruding from at least one of the surfaces, wherein the substrate and the hook-type engaging elements are both made of a cellulose ester resin composition, the cellulose resin composition contains a cellulose ester and an adipic acid ester compound in a weight ratio of cellulose ester / adipic acid ester compound of 94 / 6 to 55 / 45 (preferably 88 / 12 to 60 / 40, more preferably 87 / 13 to 70 / 30), and the orientation degree of the substrate in the machine direction is 0.120 to 0.390 (preferably 0.140 to 0.385, more preferably 0.160 to 0.370, even more preferably 0.185 to 0.360, and particularly preferably 0.200 to 0.340). [Aspect 2] A molded surface fastener according to Aspect 1, wherein the strain in the machine direction of the substrate is 2.5 to 15.0% (preferably 3.0 to 15.0%, more preferably 3.5 to 14.0%, and even more preferably 5.0 to 13.0%). [Aspect 3] A molded surface fastener according to Aspect 1 or 2, wherein the cellulose ester is cellulose acetate and has an average degree of substitution of 2.0 to 2.6 (preferably 2.1 to 2.5, and more preferably 2.3 to 2.5). [Aspect 4] A molded surface fastener according to any one of Aspects 1 to 3, wherein the cellulose ester is cellulose acetate and has a weight average molecular weight (Mw) of 100,000 to 1,000,000 (preferably 100,000 to 500,000, and more preferably 100,000 to 300,000). [Aspect 5] A molded surface fastener according to any one of Aspects 1 to 4, wherein the molded surface fastener is amorphous. [Aspect 6] A hook and loop fastener stack composed of a plurality of hook and loop fasteners, in which a substrate or base fabric of another hook and loop fastener is joined to a substrate of a molded hook and loop fastener described in any one of aspects 1 to 5, and the hook and loop fastener stack has engaging elements of the molded hook and loop fastener on one side and hook and loop fastener on the other side.[Aspect 7] A hook-and-loop fastener stack composed of a plurality of hook-and-loop fasteners, wherein the substrate of one molded hook-and-loop fastener is joined to the substrate of another molded hook-and-loop fastener, and all of the molded hook-and-loop fasteners in the hook-and-loop fastener stack are composed of the molded hook-and-loop fasteners described in any one of Aspects 1 to 5. [Aspect 8] A method for producing a molded hook-and-loop fastener according to any one of Aspects 1 to 5, comprising the steps of: pouring a melt of a cellulose ester resin composition onto the surface of a metal roll having perforated cavities, forcing the melt into the cavities, and forming a sheet-like material of the melt on the metal roll surface; and peeling the sheet-like material from the metal roll surface to obtain a molded hook-and-loop fastener comprising a substrate having a first surface and a second surface, and hook-type engaging elements or precursors thereof protruding from at least one of the surfaces. A method for producing a molded surface fastener according to any one of Aspects 1 to 5, comprising: a step of melt-extruding a cellulose ester resin composition through a slit having a predetermined shape to obtain a substrate precursor and a molded surface fastener precursor comprising a plurality of rows for engaging elements protruding from one surface of the substrate precursor; a step of making a plurality of small slits in the rows for engaging elements in the row direction from the tip of the rows toward the substrate precursor to a predetermined position on the rows; and a step of stretching the molded surface fastener precursor in the row direction to increase the spacing between the slits, thereby obtaining a molded surface fastener comprising a substrate having a first surface and a second surface, and hook-type engaging elements protruding from at least one surface of the rows.

[0016] Here, the machine direction (MD) of the substrate is the direction in which the substrate advances due to the rotation of the metal roll in the case of an injection-molded type, and is the extrusion direction or the row direction of the hook-type engaging elements in the case of an extrusion-molded type. In this specification, the range "X to Y" means "X or more and Y or less." Polyethylene adipate may be excluded from the adipic acid ester-based compound.

[0017] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms, including "at least one," unless the content clearly dictates otherwise. As used herein, the terms "and / or," "at least one," and "one or more" include any and all combinations of the associated listed items.

[0018] It should be noted that any combination of at least two elements disclosed in the claims and / or the specification and / or the drawings is included in the present invention, and in particular any combination of two or more of the claims set forth in the claims is included in the present invention.

[0019] The molded surface fastener of the present disclosure can be provided with biodegradability based on ISO 14851 while satisfying the engagement force required of a surface fastener by controlling the degree of orientation of the substrate in the machine direction.

[0020] This disclosure will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and explanation and should not be used to define the scope of this disclosure. The scope of this disclosure is defined by the accompanying claims. The drawings are not necessarily drawn to scale and are exaggerated to illustrate the principles of the present disclosure. Figure 1 is a diagram schematically showing an example of manufacturing a molded surface fastener of the present disclosure. Figure 2 is a schematic perspective view showing an example of a molded surface fastener of the present disclosure. Figure 3 is a schematic front view illustrating an engaging element of one aspect of the present disclosure. Figure 4 is a schematic partial perspective view illustrating an example of a molded surface fastener precursor. Figure 5 is a schematic partial perspective view showing an example of a molded surface fastener of the present disclosure. Figure 6 is a schematic front view illustrating an engaging element of one aspect of the present disclosure. Figure 7 is a graph illustrating a load-elongation curve obtained in a tensile test.

[0021] The molded surface fastener of the present disclosure is a molded surface fastener having a substrate having a first surface and a second surface, and a hook-type engaging element protruding from at least one of the surfaces, and both the substrate and the hook-type engaging element are composed of a cellulose ester resin composition.

[0022] [Cellulose Ester Resin Composition] The cellulose ester resin composition can use known cellulose esters, such as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, polycaprolactone-grafted cellulose acetate, acetyl methyl cellulose, acetyl ethyl cellulose, acetyl propyl cellulose, acetyl hydroxyethyl cellulose, acetyl hydroxypropyl cellulose, etc. These cellulose esters may be used alone or in combination of two or more.

[0023] Among these, preferred are cellulose ester resin compositions containing at least one selected from the group consisting of cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate, and more preferred are cellulose ester resin compositions containing cellulose acetate.

[0024] The most preferred example, cellulose acetate, will be described below as a representative example. Cellulose acetate is a natural polymer in which at least one of the three hydroxyl groups (—OH) at the 2nd, 3rd, and 6th positions of the glucose ring of cellulose is converted to an acetate ester (—OCOCH ３ Cellulose acetate is a semi-synthetic polymer in which cellulose acetate is substituted with cellulose acetate. Cellulose acetate is a plant-derived polymeric material, and can be made from the inedible parts of plants.

[0025] From the viewpoint of melt moldability, the average degree of substitution of cellulose acetate may be, for example, 2.0 to 2.6, preferably 2.1 to 2.5, and more preferably 2.3 to 2.5. The average degree of substitution is a value measured by the method described in the examples below.

[0026] Furthermore, in cellulose acetate, the degrees of substitution at the 2-, 3-, and 6-positions may or may not be uniform. For example, when the degrees of substitution are uniform, the degrees of substitution at the 2-, 3-, and 6-positions may all exceed 0.70. On the other hand, when the degrees of substitution are nonuniform, either one of the degrees of substitution at the 2- and 3-positions may be 0.70 or less. For example, cellulose acetate having either one of the degrees of substitution at the 2- and 3-positions of 0.70 or less can also be produced with reference to Mokuzai Gakkaishi, Vol. 60, pp. 144-168 (2014) and Biomacromolecules, 13, 2195-2201 (2012).

[0027] The weight average molecular weight (Mw) of the cellulose acetate may be, for example, 100,000 to 1,000,000, preferably 100,000 to 500,000, and particularly preferably 100,000 to 300,000. The weight average molecular weight is a value measured by the method described in the examples below.

[0028] Cellulose acetate can be produced, for example, by reacting a raw cellulose (e.g., various wood pulps, linter pulp, etc.) with an acylating agent such as acetic anhydride or glacial acetic acid in the presence of an acylation catalyst such as sulfuric acid to acetylate it to a desired average substitution degree.

[0029] Common cellulose acetates are commercially available from Daicel Corporation under the trade names "L-20," "L-30," "L-50," and "L-70" as part of the L series.

[0030] The cellulose ester resin composition contains an adipic acid ester compound from the viewpoints of improving the flowability during melt molding and lowering the degree of orientation of the substrate of the surface fastener in the machine direction.

[0031] Examples of the adipic acid ester compound include esters of adipic acid and at least one alcohol selected from the group consisting of aromatic alcohols and aliphatic alcohols. The adipic acid ester compounds may be used alone or in combination.

[0032] Examples of the esters of adipic acid and aliphatic alcohols include dibutyl adipate, dioctyl adipate, dimethoxyethoxyethyl adipate, and dibutoxyethoxyethyl adipate.

[0033] Examples of the esters of adipic acid and aromatic alcohols include diphenyl adipate, dibenzyl adipate, dicresyl adipate, and dixylyl adipate.

[0034] As the mixed ester of adipic acid with an aromatic alcohol and an aliphatic alcohol, benzyl alkyl diglycol adipate is preferred. Benzyl alkyl diglycol adipate may be used alone, or a mixture of an ester of adipic acid with an aromatic alcohol and / or an ester of adipic acid with an aliphatic alcohol containing benzyl alkyl diglycol adipate may be used.

[0035] When a mixture containing benzyl alkyl diglycol adipate is used, it is preferred to use one containing 35% by weight or more of benzyl alkyl diglycol adipate.

[0036] The alkyl group of the benzyl alkyl diglycol adipate may be either linear or branched, but it is preferable to use a linear one.

[0037] The number of carbon atoms in the alkyl group may be, for example, 1 to 20, preferably 1 to 8, and more preferably 1 to 4. Particularly preferred benzyl alkyl diglycol adipates have a linear alkyl group having 1 to 4 carbon atoms, such as benzyl methyl diglycol adipate, benzyl ethyl diglycol adipate, benzyl n-propyl diglycol adipate, and benzyl n-butyl diglycol adipate.

[0038] Adipate ester compounds are commercially available from Daihachi Chemical Industry Co., Ltd. under the trade name "DAIFATTY-101," for example.

[0039] From the viewpoint of bleed-out resistance and melt moldability, the weight ratio of cellulose ester to adipic acid ester compound in the molded surface fastener may be 94 / 6 to 55 / 45, preferably 88 / 12 to 60 / 40, and more preferably 87 / 13 to 70 / 30, in terms of cellulose ester / adipic acid ester compound. By setting the weight ratio of cellulose ester to adipic acid ester compound within the above range, excellent moldability is achieved, making it easier to control the degree of orientation, and as a result, biodegradability can be improved. Furthermore, a certain degree of hardness can be imparted, allowing the surface fastener to exert the required engaging force. On the other hand, if the content of the adipic acid ester compound is too high outside the above range, even if the degree of orientation can be controlled, the surface fastener will be too soft to exert the required engaging force. On the other hand, if the content of the adipic acid ester compound is too low, not only will it be difficult to control the degree of orientation, but the surface fastener will be too hard and brittle to exert the required engaging force.

[0040] The cellulose ester resin composition may be, for example, a pellet-shaped product made of a kneaded mixture obtained by kneading a cellulose ester, an adipic acid ester compound, and optional additives (e.g., plasticizers, flame retardants, heat stabilizers, antioxidants, antistatic agents, coloring inhibitors, matting agents, radical inhibitors, colorants, fluorescent brighteners, antibacterial agents, etc.) under heating in an extruder. Prior to kneading, the cellulose ester, the adipic acid ester compound, and optional other additives may be mixed dry or wet using a mixer such as a Henschel mixer, if necessary. In this case, the temperature inside the mixer may be a temperature at which the cellulose ester does not melt, for example, in the range of 20°C or higher and lower than 200°C.

[0041] The cellulose ester resin composition may contain 50% by weight or more of cellulose ester, preferably 55 to 94% by weight, more preferably 60 to 88% by weight, and even more preferably 70 to 87% by weight. In this specification, the cellulose ester resin composition is a component that constitutes the substrate of the molded surface fastener and the main body of the hook-type engaging element, and adhesives applied to the surface do not fall under the category of components of the cellulose ester resin composition. Note that components that are considered to have bled out are considered to be components of the cellulose ester resin composition.

[0042] [Method for manufacturing molded surface fasteners] Molded surface fasteners may be either injection molded or extrusion molded, and can be manufactured by adjusting the orientation degree of the substrate in the machine direction within a predetermined range depending on the type.

[0043] [Method for manufacturing an injection-molded type molded hook-and-loop fastener] The method for manufacturing an injection-molded type molded hook-and-loop fastener (I) comprises the steps of pouring a molten cellulose ester resin composition onto the surface of a metal roll having a perforated cavity, forcing the molten material into the cavity, and forming a sheet-like material of the molten material onto the surface of the metal roll, and peeling the sheet-like material from the surface of the metal roll to obtain a molded hook-and-loop fastener comprising a substrate having a first surface and a second surface, and hook-type engaging elements or precursors thereof protruding from at least one of the surfaces.

[0044] Fig. 1 shows a schematic diagram of an example of the production of a molded surface fastener of the present disclosure. As shown in Fig. 1, a melt (M) of a cellulose ester resin composition is preferably extruded from a T-die (T) into a gap between a metal roll (R1) having a perforated cavity and another drum roll (R2) located opposite the metal roll (R1). The extruded melt (M) of the cellulose ester resin composition contacts the metal roll (R1) and is simultaneously compressed by the drum roll (R2). As a result, the resin composition is filled into the cavity and adheres to the surface of the metal roll (R1) with a uniform thickness.

[0045] On the other hand, while the metal roll (R1) is rotating, the resin composition present in the cavity and on the surface of the metal roll (R1) is cooled and solidified by the refrigerant constantly circulating within the metal roll (R1), and a sheet-like material (S) can be obtained.

[0046] Thereafter, the sheet-like material (S) is taken up from the surface of the metal roll (R1) at a predetermined take-up speed by a pair of nip rolls (R3, R3) whose gap is adjusted so that the substrate of the obtained molded surface fastener has a uniform thickness, whereby the hook-type engaging element portions are pulled out of the cavities and the sheet-like material (S) is stretched and peeled off from the surface of the metal roll (R1), thereby obtaining a molded surface fastener (10). Figure 2 is a schematic perspective view showing an example of such a molded surface fastener (10).

[0047] The molded surface fastener (10) peeled off from the metal roll (R1) may comprise precursors of hook-type engaging elements. For example, if the pulled-out engaging elements are precursors of hook-type engaging elements, a step of shaping them into hook-type engaging elements may be further carried out. Such a step may include, for example, a step of heating and melting the tip of the precursor of the hook-type engaging element protruding from the substrate to form a mushroom-shaped swollen head.

[0048] Suitable conditions are explained below. The fluidity of the cellulose ester resin composition to be injection molded can be controlled by increasing or decreasing the amount of plasticizer, such as an adipic acid ester compound, and the degree of orientation of the resulting molded surface fastener can be controlled. From the viewpoint of processability in injection molding and control of the degree of orientation, the weight ratio of cellulose ester to adipic acid ester compound (cellulose ester / adipic acid ester compound) is 94 / 6 to 55 / 45, preferably 85 / 15 to 60 / 40, more preferably 80 / 20 to 65 / 35, and even more preferably 75 / 25 to 70 / 30. If the amount of plasticizer is too small and outside the above range, the resin composition will have low fluidity when melted and will remain hard and brittle after solidification, making it prone to cracking in the orientation direction (machine direction). On the other hand, if the amount of plasticizer is too large, the plasticizer may bleed out during molding and when maintained at high temperatures.

[0049] The temperature (or melting temperature) of the melt of the cellulose ester resin composition can be appropriately set depending on the type of resin composition. For example, the nozzle temperature during discharge may be 200 to 280°C, preferably 210 to 260°C, and more preferably 210 to 250°C.

[0050] The molten material that comes into contact with the metal roll is forced into the cavity as the metal roll rotates, while being cooled and solidified, and a sheet-like material can be formed on the metal roll surface. The metal roll surface is controlled to a predetermined temperature from the viewpoint of controlling the orientation of the molten material. From the viewpoint of controlling the degree of orientation of the hook-and-loop fastener (particularly the substrate), the metal roll surface may be, for example, 80 to 135°C (e.g., 80 to 130°C), preferably 90 to 130°C (e.g., 96 to 130°C), more preferably 90 to 120°C (e.g., 95 to 115°C), and even more preferably 100 to 125°C. When molding a hook-and-loop fastener by injection molding, the metal roll surface temperature (mold surface temperature) when the hook-type engaging element portion is pulled out of the cavity of the metal roll (mold roll) and peeled off from the surface of the metal roll has a significant effect on cracking of the sheet-like material in the MD direction. If the metal roll surface temperature during peeling is low, stress is concentrated at the base portion of the hook-type engaging elements or at portions corresponding to the shape of the hook-type engaging elements (for example, the inverted J-shaped bend portion in the case of a wavy cross section as described below), and the forced pulling tends to promote orientation in the MD direction and make cracks in the same direction more likely to occur. The metal roll surface temperature (mold surface temperature) is preferably a temperature just before the running sheet-like material melts and breaks. Although this temperature varies depending on the amount of plasticizer added, a temperature near the glass transition temperature of the cellulose ester resin composition is appropriate. For example, the metal roll surface temperature is preferably 20 to 40°C higher than the metal roll surface temperature when injection molding a general-purpose resin, i.e., molding is preferably performed under conditions of slow cooling relative to the temperature of the molten material.

[0051] Furthermore, from the viewpoint of productivity, the take-up speed from the metal roll by the nip roll may be, for example, 8 to 25 m / min, preferably 10 to 20 m / min, and more preferably 13 to 18 m / min. If the take-up speed by the nip roll is less than 8 m / min, productivity will be poor, and if it exceeds 25 m / min, problems in production will tend to increase, which may result in a decrease in yield.

[0052] The shape of each cavity provided in the metal roll may be any known or conventional shape, and may be, for example, a cavity capable of forming an engaging element having a wavy cross section as shown in Figure 3. Here, "wavy" means that the cross section of the engaging element becomes thinner from the base to the tip of the substrate, gradually curves halfway, and the tip faces in a direction slightly closer to the substrate surface. Alternatively, the shape of the cavity may be approximately cylindrical, and in that case, the protruding portion of the approximately cylindrical shape can be used as a precursor of a hook-type engaging element protruding from the substrate.

[0053] The individual cavities provided in the metal roll may be cavities for forming engaging elements of a single shape, or may be cavities for forming engaging elements of multiple shapes. The cavities are preferably formed using a ring-shaped mold, and although cavities of different shapes may be formed in the ring-shaped mold, it is preferable that multiple cavities of the same shape are formed. The ring-shaped mold may be used alone or in combination of two or more types.

[0054] An example of a cavity for forming a plurality of shapes is, for example, a ring-shaped mold having a hook-type engagement element shape having a first shape carved on its outer circumference, a metal ring not carved in such a shape, a ring-shaped mold having a hook-type engagement element shape having a second shape that is different from the above hook-type engagement element shape carved on its outer circumference, and a metal ring not carved in such a shape, which are stacked one on top of the other in this order, thereby making it possible to prepare a mold roll having a large number of cavities in the shape of hook-type engagement elements having a first shape and cavities in the shape of hook-type engagement elements having a second shape on the outer surface of the metal roll.

[0055] Such a metal roll has on its surface a plurality of cavities curved in the circumferential direction of the roll arranged in rows in the circumferential direction, and there are also a plurality of such rows in the width direction of the metal roll, with the direction of curvature of the cavities being reversed for each row or for each set of rows.

[0056] The thickness of the ring-shaped mold can be set appropriately depending on the shape of the cavity, and may be, for example, 0.2 to 0.5 mm.

[0057] Furthermore, if necessary, a cavity for a hook-type engaging element may be provided on the drum roll (R2) side, thereby obtaining a so-called double-sided surface fastener having hook-type engaging elements on both the first and second surfaces.

[0058] An example of a molded hook-and-loop fastener manufactured by the manufacturing method (I), i.e., by injection molding, is shown in Figure 2. As shown in Figure 2, the molded hook-and-loop fastener (10) may have a substrate (11) and hook-type engaging elements (12) rising from its surface. For example, the hook-type engaging elements (12) shown in Figure 2 satisfy the following (1) and (2): (1) the hook-type engaging elements become thinner from the base to the tip, and are gradually bent halfway so that the tip points in a direction slightly closer to the substrate; (2) a plurality of hook-type engaging elements are lined up in a row in the same direction as the bending direction of the hook-type engaging elements, and further, the bending direction is opposite for each row or for each set of rows.

[0059] The specific extent to which the tip of the hook-type engaging element faces in a direction slightly approaching the substrate is not particularly limited, but it is preferable that the lower end of the tip of the hook-type engaging element is closer to the substrate by 2 to 8% of the height of the hook-type engaging element than the lower end of the top of the hook-type engaging element. This is explained using FIG. １ -H ２ ) / H ０ × 100 = 2 to 8. ０ is the height of the hook-type engaging element from the substrate, H １ is the height of the bottom end of the top of the hook-shaped engaging element from the substrate, H ２ and r respectively mean the height of the lower end of the tip of the hook-shaped engaging element from the substrate. These values ​​are calculated as the average value of 10 arbitrarily selected hook-shaped engaging elements. In addition, the thickness T of the substrate １ It is preferable to measure the thickness of the substrate in a portion where no hook-type engaging element is present.

[0060] Preferably, the width of the hook-type engaging element at the top of the hook-type engaging element is greater than the thickness of the hook-type engaging element. For example, this will be explained using FIG. 4. FIG. 4 is a schematic perspective view showing an enlarged example of a hook-type engaging element constituting a hook-type molded surface fastener. The width (W) of the hook-type engaging element at the top of the hook-type engaging element shown in FIG. 4 is greater than the thickness (T) of the hook-type engaging element at the top. ２ ), i.e., W>T ２ If this requirement is met, it is possible to prevent the hook-type engaging elements from being cut when the hook-type molded surface fastener is pulled out of the cavity during molding, and to prevent cracks from occurring at the bent portions of the engaging elements. These values ​​are also the average values ​​of 10 hook-type engaging elements selected arbitrarily, as above.

[0061] A preferred size of the hook-type engaging element is the height (H ０ ) is, for example, 1.0 to 2.0 mm, the spread (A) of the base (root part) is, for example, 0.7 to 1.3 mm, the spread (B) at a point two-thirds of the height of the engaging element from the base is, for example, 0.15 to 0.4 mm, and the hook-shaped engaging element preferably begins to gradually bend, for example, from about one-half to three-quarters of the height of the engaging element from the base.

[0062] In addition, in the hook-type molded surface fastener, it is preferable that 98% or more of the hook-type engaging elements have tip portions that face in a direction approaching the surface of the base body.

[0063] Furthermore, the width (W) of the hook-type engaging element at the top of the hook-type engaging element shown in Figure 4 is preferably 0.2 to 0.4 mm, and the width of the hook-type engaging element may be the same from the base to the tip of the hook-type engaging element, or may become thinner as it approaches the tip. However, when the ring-shaped mold described above is used, the width of the hook-type engaging element will inevitably be almost the same from the base to the tip of the hook-type engaging element. And the thickness (T) of the hook-type engaging element at the top ２) is preferably 0.15 to 0.35 mm, which is a value smaller than the above W. It is preferable that each hook-type engaging element constituting the hook-type molded surface fastener is a single piece all the way to the tip, which means that it does not split into multiple pieces along the way.

[0064] As shown in Figure 2, in a hook-type molded surface fastener, a plurality of such hook-type engaging elements are arranged in a row in the same direction as the bending direction of the hook-type engaging elements, and the spacing (C) between adjacent hook-type engaging elements in the row direction is preferably 1.2 to 2.2 mm, i.e., one hook-type engaging element is present per row length of 1.2 to 2.2 mm. More preferably, it is one hook-type engaging element per row length of 1.3 to 1.8 mm. Furthermore, the spacing between adjacent rows of engaging elements is preferably in the range of 0.4 to 1.0 mm, i.e., one row of hook-type engaging elements is present on a substrate with a width of 0.4 to 1.0 mm. More preferably, one row of hook-type engaging elements is present in a width of 0.5 to 0.8 mm.

[0065] [Method for manufacturing an extrusion-molded type molded surface fastener] The method for manufacturing an extrusion-molded type molded surface fastener (II) comprises the steps of: melt-extruding a cellulose ester resin composition through a slit having a predetermined shape to obtain a substrate precursor and a molded surface fastener precursor having a plurality of rows for engaging elements protruding from one surface of the substrate precursor; making a plurality of small slits in the rows for engaging elements in the row direction from the tip of the rows toward the substrate precursor to a predetermined position on the rows; and stretching the molded surface fastener precursor in the row direction to increase the spacing between the slits, thereby obtaining a molded surface fastener having a substrate having a first surface and a second surface, and hook-type engaging elements protruding from at least one surface of the rows.

[0066] In manufacturing method (II), first, in the step of obtaining a molded surface fastener precursor, a cellulose ester resin composition is melt-extruded through a slit having a predetermined shape to obtain a substrate precursor and a molded surface fastener precursor having a plurality of engaging element rows protruding from one side of the substrate precursor. The fluidity of the cellulose ester resin composition used in extrusion molding can be controlled by increasing or decreasing the amount of plasticizer, such as an adipate ester compound, thereby controlling the degree of orientation of the resulting molded surface fastener. From the viewpoint of processability in extrusion molding and control of the degree of orientation, the weight ratio of cellulose ester to adipate ester compound is 94 / 6 to 55 / 45, preferably 85 / 15 to 60 / 40, and more preferably 80 / 20 to 70 / 30. If the amount of plasticizer is too small and outside the aforementioned range, the resin composition will have low fluidity when melted and will remain hard and brittle even after solidification, making it prone to cracking in the orientation direction (machine direction). On the other hand, if the amount of plasticizer is too large, the plasticizer may bleed out during molding or when maintained at high temperatures. The temperature (or melting temperature) of the melt of the cellulose ester resin composition can be, for example, within the range described in the above-mentioned production method (I).

[0067] A resin composition for a hook-type molded surface fastener is melt-extruded from a nozzle having a slit formed with a desired cross-sectional shape, and then cooled, thereby obtaining a molded surface fastener precursor having the cross-sectional shape.

[0068] For example, Fig. 5 shows a schematic partial perspective view illustrating an example of a molded surface fastener precursor. In Fig. 5, rows (25, 25) for hook-type engaging elements protrude from the first surface of the substrate precursor (24) in the extrusion direction (X) of the molded surface fastener precursor (20). Here, the rows for hook-type engaging elements are continuous convex portions provided to form the hook-type engaging elements. The extrusion direction (X) of the molded surface fastener precursor (20) is the same as the direction of the rows for hook-type engaging elements. In Fig. 5, the substrate precursor (24) shows a cross section (24') cut between the rows for hook-type engaging elements (25), and the molded surface fastener precursor (20) may have further rows for hook-type engaging elements (25) formed continuously from the same cross section.

[0069] When the direction perpendicular to the extrusion direction (X) is the width direction (Y), the width of the molded surface fastener precursor (20) may be, for example, 20 to 80 mm, preferably 30 to 60 mm. The number of rows for hook-type engaging elements present in the width direction of the molded surface fastener precursor may be, for example, 3 to 8, preferably 4 to 6, per 1 cm of width of the molded surface fastener precursor (20).

[0070] If necessary, the molded surface fastener precursor may have embedding element rows protruding from the side (second surface) opposite the first surface of the substrate precursor (24). Here, the embedding element rows are continuous convex portions provided for forming embedding elements. The embedding element rows may be provided on the second surface of the substrate precursor at positions opposite to the hook-type engaging element rows formed on the first surface. However, from the viewpoint of evenly distributing the tensile force applied to the hook-type engaging elements to the resin molded body, it is preferable that the embedding element rows protrude from the second surface of the substrate precursor at positions corresponding to the spaces between adjacent hook-type engaging element rows on the first surface of the substrate precursor. The number of embedding element rows may also be, for example, 3 to 8, preferably 4 to 6, per cm of width of the molded surface fastener precursor. The number of embedding element rows is preferably the same as the number of hook-type engaging element rows.

[0071] In addition, the substrate precursor may have rows for hook-type engaging elements formed on the first and second surfaces, in which case a so-called double-sided surface fastener having hook-type engaging elements on the first and second surfaces can be obtained.

[0072] Next, a plurality of small slits are made in the rows (25) for hook-type engaging elements in the width direction (Y) of the molded surface fastener precursor (20) from the tip of the rows in the height direction toward the substrate precursor to a predetermined position on the rows. Note that slits may or may not be made in the rows for embedded elements.

[0073] Furthermore, by making the slits in the rows for hook-type engaging elements not to the base of the rows but halfway through, the unslit lower portions of the rows can be used as ridges of the molded surface fastener. In this case, the ridges will be continuous in the extrusion direction of the molded surface fastener. There are no particular restrictions on the spacing of the slits provided in the rows for hook-type engaging elements and, if necessary, rows for embedded elements, but it is preferably 0.20 to 0.60 mm, and more preferably 0.30 to 0.55 mm.

[0074] Next, after the slits are made, the molded surface fastener precursor is stretched in the extrusion direction (X). By stretching, the slits made in each row widen, and the rows become rows of numerous independent hook-type engaging elements, resulting in a surface fastener or its precursor comprising a substrate having a first surface and a second surface, and hook-type engaging elements or their precursors protruding from at least one of the surfaces. Therefore, the extrusion direction (X) is also the row direction of the hook-type engaging elements.

[0075] The stretching ratio (the ratio of the length of the molded surface fastener precursor after stretching to the length of the molded surface fastener precursor before stretching) may be, from the viewpoint of controlling the degree of orientation of the substrate, for example, 1.40 to 2.60 times, preferably 1.50 to 2.50 times, and more preferably 1.60 to 2.45 times.

[0076] The stretching temperature can be appropriately set depending on the softening temperature of the cellulose ester resin composition, and may be, for example, 110 to 180°C, preferably 120 to 170°C, and more preferably 125 to 150°C.

[0077] When the molded surface fastener is manufactured by the manufacturing method (II), i.e., extrusion molding, one embodiment of the molded surface fastener is shown in Figure 6. As shown in Figure 6, the molded surface fastener (30) may have a substrate (31) and hook-type engaging elements (32) rising from its surface. Furthermore, the hook-type engaging elements (32) have stem portions (33) rising from the substrate (31) and protruding portions (36). In addition, the stem portion (33) has ridge portions (38) formed on the substrate (31) side. The protruding portions (36) protrude symmetrically from the stem portion (33) in the left-right direction, with two protruding portions (36) protruding above and below the stem portion (33) in a direction approximately perpendicular to the row direction (X) of the hook-type engaging elements. The tips of the protruding portions (36) are all close to the surface of the substrate (31).

[0078] When the row direction (X) of the hook-type engaging elements is used as a reference, the ratio of the spacing (mm) between the stem portions to the thickness (mm) of the stem portions may be, for example, 0.30 to 0.80, more preferably 0.45 to 0.65. Such spacing is preferable because it can prevent the loop-type engaging elements from engaging with specific hook-type engaging elements in a biased manner, which can prevent such loop-type engaging elements from breaking, and / or prevent the hook-type engaging elements from falling over.

[0079] The cross-sectional shape of the hook-type engaging element may be various, for example, as shown in FIG. 7 , engaging elements having a substantially Y-shaped cross section, engaging elements having an umbrella-shaped cross section, engaging elements having a substantially T-shaped cross section, engaging elements having a mushroom-shaped cross section, engaging elements having an arrowhead-shaped cross section, engaging elements having a two-stage arrowhead-shaped cross section, engaging elements having a wavy cross section, etc. FIG. 7 shows a schematic cross-sectional view of each engaging element protruding from the substrate. Furthermore, as shown in FIG. 8 , the shape of these engaging elements may have ridges in the portion that contacts the substrate, in which case the engaging element may protrude from the ridges. The shape of the hook-type engaging element may also be a precursor shape capable of forming a mushroom-shaped bulging head, as described for the injection molding type.

[0080] [Molded Hook-and-Loop Fastener] The molded hook-and-loop fastener has a substrate having a first surface and a second surface, and hook-type engaging elements protruding from at least one of the surfaces, wherein the substrate and the hook-type engaging elements are both made of a cellulose ester resin composition, and the orientation degree of the substrate in the machine direction is 0.120 to 0.390, preferably 0.140 to 0.385, more preferably 0.160 to 0.370, even more preferably 0.185 to 0.360, and particularly preferably 0.200 to 0.340. Here, the orientation degree is a value measured by the method described in the Examples below.

[0081] If the degree of orientation is too low, it becomes difficult to form the engaging elements of the molded surface fastener, and the surface fastener cannot exhibit the required engaging force. If the degree of orientation is too high, it is undesirable because it reduces the biodegradability according to ISO 14851. Furthermore, if the degree of orientation is too high, the substrate portion of the surface fastener is likely to become brittle, and there is a risk that the engaging force will decrease after repeated use.

[0082] In addition, when the front side of the substrate is the first surface and the back side is the second surface, the hook-type engaging element may protrude only from the first surface, or may protrude from both the first surface and the second surface.

[0083] The molded surface fastener may have a degree of biodegradation after 3 days of 5% or more, preferably 7% or more, and more preferably 9% or more, as determined by ISO 14851. The degree of biodegradation according to ISO 14851 is a value measured by the method described in the examples below.

[0084] From the viewpoints of biodegradability and independence of the engaging elements, the strain in the machine direction of the substrate of the molded surface fastener may be, for example, 2.5 to 15.0%, preferably 3.0 to 15.0%, more preferably 3.5 to 14.0%, and more preferably 5.0 to 13.0%. The strain is a value measured by the method described in the examples below. In the case of extrusion molding, it can be controlled by the stretching ratio, etc. In the case of injection molding, there is no stretching step, but the strain of the substrate can be controlled by the amount of plasticizer added, the surface temperature of the metal roll (mold roll), etc.

[0085] The modulus of elasticity in the machine direction of the substrate of the molded surface fastener may be, for example, 10,000 to 50,000 N, preferably 12,000 to 45,000 N, and more preferably 13,000 to 42,000 N, from the viewpoint of the handleability (flexibility) of the substrate portion. The modulus of elasticity is a value measured by the method described in the Examples section below. The modulus of elasticity of the substrate of the molded surface fastener is primarily affected by the addition ratio and degree of orientation of the cellulose ester and plasticizer in the cellulose ester resin composition; as the amount of plasticizer increases, the modulus becomes lower and the substrate becomes softer, while as the amount of plasticizer decreases, the modulus becomes higher and the substrate becomes hard and brittle. Furthermore, as the degree of orientation increases, the modulus of elasticity tends to increase, and as the degree of orientation decreases, the modulus of elasticity tends to decrease.

[0086] The thickness of the substrate of the molded surface fastener may be, for example, 0.1 to 0.4 mm, preferably 0.2 to 0.3 mm, from the viewpoint of flexibility and strength.

[0087] The density of the hook-type engaging elements present on the substrate of the molded surface fastener is, from the viewpoint of the engaging force, for example, 40 to 160 pieces / cm ２ , preferably 50 to 140 pieces / cm ２ may be in the range of

[0088] [Overlaid Hook and Loop Fastener Material] The present disclosure may include an overlaid hook and loop fastener material. The overlaid hook and loop fastener material is an assembly of multiple hook and loop fasteners, in which a substrate or a base fabric of another hook and loop fastener is joined to a substrate of the molded hook and loop fastener of the present disclosure, and one surface of the molded hook and loop fastener is provided, and the other surface of the other hook and loop fastener is provided. Here, the other hook and loop fastener may be a molded hook and loop fastener or a woven hook and loop fastener.

[0089] In addition, the hook-and-loop fastener stack may have a substrate of one molded hook-and-loop fastener joined to a substrate of another molded hook-and-loop fastener, and all of the molded hook-and-loop fasteners in the hook-and-loop fastener stack may be composed of the molded hook-and-loop fastener of the present disclosure.

[0090] For example, the surface fastener stack may have hook-type engaging elements on both surfaces. For example, two molded surface fasteners of the present disclosure are prepared, and the second surfaces of the substrates of the respective molded surface fasteners (i.e., the surfaces on which engaging elements are not formed) are bonded together by thermocompression bonding with a hot-melt resin (wherein the melting point or softening point of the hot-melt resin is lower than the softening point of the molded surface fastener) or by a biodegradable adhesive or the like, to obtain a molded surface fastener stack having hook-type engaging elements on both the front and back surfaces.

[0091] Alternatively, one molded hook-and-loop fastener of the present disclosure and one loop-type hook-and-loop fastener made of biodegradable fibers may be prepared, and the base fabric of the loop-type hook-and-loop fastener may be bonded to the second surface of the substrate of the molded hook-and-loop fastener by thermocompression or with a biodegradable adhesive, etc., to form a molded hook-and-loop fastener stack having hook-type engaging elements on the front surface and loop-type engaging elements on the back surface.

[0092] These hook-and-loop fasteners may completely overlap each other, or may only partially overlap. For example, when engaging elements are formed on the front and back surfaces, the engaging elements may be formed at the backs of the fasteners. Alternatively, when engaging elements are formed on the front and back surfaces, the engaging elements on the front surface and the engaging elements on the back surface may not overlap but may be formed at a predetermined distance.

[0093] For example, the second surfaces of the substrates of the hook-type molded surface fastener and the loop-type surface fastener are overlapped so that only their ends overlap, and the surface on which the hook-type engaging elements are present is the front side, and the surface on which the loop-type engaging elements are present is the back side, and the two are joined at this overlapping portion by a biodegradable adhesive or thermocompression bonding, so that the hook-type engaging elements are present on the front side and the loop-type engaging elements are present on the back side at a location away from where the hook-type engaging elements are present (i.e., the locations on which the hook-type engaging elements and the loop-type engaging elements are present are not back-to-back, but are sandwiched between the joined location and extend in directions away from each other).

[0094] As the biodegradable loop surface fastener (particularly, a marine biodegradable loop surface fastener) to be used as such an engaging partner, a loop surface fastener made of various biodegradable fibers is preferably mentioned, and a loop surface fastener made of a cellulose ester fiber as the biodegradable fiber is particularly preferred because it has excellent biodegradability and is easy to handle. For example, as the cellulose ester fiber, a cellulose ester fiber obtained by dissolving a resin equivalent to the resin used in the present disclosure in acetone and subjecting it to dry spinning, or a cellulose ester fiber obtained by melt spinning, etc.

[0095] Examples of such loop surface fasteners made of biodegradable fibers include those in which loops made of the same biodegradable fibers are present on the surface of a nonwoven fabric or woven or knitted fabric made of such biodegradable fibers. Specifically, in the case of nonwoven fabrics, examples include nonwoven fabrics in which biodegradable fibers are made into a web, entangled by needle punching or the like, and the surface is raised as necessary to form loops made of the same biodegradable fibers on the surface.

[0096] In the case of woven or knitted fabrics, examples of such loop fasteners include a woven fabric in which a biodegradable fiber is used as a spun yarn, and a woven fabric is made using this spun yarn as the warp and weft, and such spun yarn is woven into the woven fabric parallel to the warp so that loops here and there protrude from the surface of the woven fabric, and a knitted fabric in which a knitted fabric is made using a spun yarn made of such a biodegradable fiber, and the surface of the knitted fabric is raised with card clothing or the like so that loops made of the biodegradable fiber are present on the woven fabric surface.Furthermore, when the biodegradable fiber is a multifilament yarn, a woven fabric can be made using the multifilament yarn as the warp and weft, and a multifilament yarn for loop-type engaging elements can be woven parallel to the warp so that loops here and there protrude from the surface of the woven fabric.

[0097] Furthermore, such biodegradable multifilament yarns may be made into a nonwoven fabric by a spunbonding method, and the surface thereof may be raised to have loops made of biodegradable fibers protruding from the surface. In the case of a loop surface fastener, it is preferable to heat-pressure-bond the back surface or a part of the back surface to fix the fibers together and prevent the loop-type engaging elements from being pulled out of the base fabric. Furthermore, in the case of a biodegradable surface fastener as described above in which hook-type engaging elements are present on the front surface and loop-type engaging elements are present on the back surface, and in the case of a biodegradable surface fastener in which hook-type engaging elements are present on the front surface and loop-type engaging elements are present on the back surface at a location away from the hook-type engaging elements, the biodegradable loop surface fastener is required to have sufficient tensile strength by itself, and therefore the above-mentioned tricot knit fabric is preferred as the biodegradable loop surface fastener.

[0098] The molded hook-and-loop fastener of the present disclosure has sufficient engaging force and is biodegradable in the ocean. Therefore, it can be used in a variety of fields where biodegradability can be utilized, and can be effectively used in many applications, including agricultural materials, forestry materials, fisheries materials, civil engineering materials, clothing materials, household materials, sanitary materials, and medical materials. Furthermore, since such molded hook-and-loop fasteners exhibit good biodegradability in soil, they can be used, for example, for bundling and fastening in various marine aquaculture facilities, and for fastening in soil or earth where agricultural crops are grown. In particular, because they are marine biodegradable, they are suitable because they can exert engaging force when bundling and fastening in various marine aquaculture facilities, and because they decompose with age, they do not pose a threat to marine life.

[0099] By throwing an item secured with a molded hook-and-loop fastener into the ocean or soil, the fastening by the hook-and-loop fastener will disappear after a specified period of time, and the item can also be used in applications where complete biodegradation is required.

[0100] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples. In the following examples, various physical properties were measured by the following methods.

[0101] [Weight-average molecular weight of cellulose acetate] The weight-average molecular weight Mw of cellulose acetate can be determined by GPC analysis under the following conditions: Solvent: NMP Measurement column: Two PolyPore (7.8 mmφ×30 cm) manufactured by Agilent Technologies, Inc., with guard column Flow rate: 0.5 ml / min Temperature: 29°C Sample concentration: 0.5 wt% Injection volume: 50 μl Detection: RI Standard substance: PMMA (molecular weight 675,500, molecular weight 504,500, molecular weight 223,900, molecular weight 66,650, molecular weight 26,550, molecular weight 6,140, ​​molecular weight 1,780)

[0102] [Average Substitution Degree of Cellulose Acetate] The acetyl substitution degrees at the 2-, 3-, and 6-positions of the glucose ring of cellulose acetate can be measured by NMR according to the method of Tezuka (Tezuka, Carbohydr. Res., 273, 83 (1995)). That is, the free hydroxyl groups of a cellulose acetate sample are propionylated with propionic anhydride in pyridine. The obtained sample is dissolved in deuterated chloroform, １３ The C-NMR spectrum is measured. Carbon signals of the acetyl group appear in the region of 169 to 171 ppm in the order of 2-, 3-, and 6-positions from the high magnetic field, and signals of the carbonyl carbon of the propionyl group appear in the same order in the region of 172 to 174 ppm. The degree of acetyl substitution at the 2-, 3-, and 6-positions of the glucose ring in the original cellulose acetate can be determined from the abundance ratio of the acetyl group and the propionyl group at the corresponding positions (in other words, the area ratio of each signal). The degree of acetyl substitution can be calculated as follows: １３ In addition to C-NMR, １ It can also be analyzed by H-NMR. The average degree of acetyl substitution in the present disclosure is the sum of the degrees of acetyl substitution at the 2-, 3-, and 6-positions of the glucose ring of cellulose acetate determined by the above-mentioned measurement method.

[0103] [Orientation Degree] Wide-angle X-ray scattering measurement was performed under the following measurement conditions by setting the molded surface fastener in an apparatus and irradiating the flat surface of the substrate with X-rays, avoiding the engaging elements: <Measurement Conditions> Model: Bruker D8 Discover IμS X-ray source: Cu Collimator diameter: 0.5 mm Voltage: 50 kV Current: 1 mA Detector: 2D PSPC VANTEC-500 Exposure time: 10 minutes / frame

[0104] The two-dimensional diffraction image obtained by the above measurement was converted into an azimuth angle-intensity profile, with the horizontal axis being the azimuth angle (γ) and the vertical axis being the X-ray diffraction intensity, under the conditions of a diffraction angle (2θ) of 7.5 to 8.5°, an azimuth angle (γ) of 0 to 360°, and a step width of 0.5°. The degree of orientation f was calculated from the obtained azimuth angle-intensity profile using the following equations (1) and (2). In formulas (1) and (2), f is the degree of orientation, I ｉ is the azimuth angle θ ｉThis is the peak intensity when <cos ２ θ> is the average value of the orientation state of all molecules, and f=0 in the case of no orientation and f=1 in the case of complete orientation. The integral range i is the azimuth angle from 0 to 90 degrees.

[0105] [Strain (%)] A sample of 25 mm (width) x 200 mm (length) was cut out from the molded surface fastener, with the machine direction (MD) as the length direction, and a tensile test was carried out using an autograph manufactured by Shimadzu Corporation. Then, with reference to JIS K 7127 (1999), the increase in the gauge length until breakage was divided by the initial gauge length to calculate the value using the following formula. The measurement was carried out 10 times and the average value was calculated.

[0106] [Elastic modulus (N)] A sample of 25 mm (width) x 200 mm (length) was cut out from the molded surface fastener, with the machine direction (MD) as the length direction, and a tensile test was performed using an autograph manufactured by Shimadzu Corporation. With reference to JIS L 1013 (2021), as shown in Figure 9, the maximum point A (maximum point of tangent angle) of the load change with respect to the elongation change was determined near the origin from the load-elongation curve obtained in the tensile test, and the average value of 10 times was calculated using the following formula. E: tensile modulus (N) P: load (N) at maximum point A of the tangent angle l: test length (mm) l': length of TH (mm), where H is the intersection of the perpendicular line and the horizontal axis at maximum point A, and T is the intersection of the tangent line and the horizontal axis.

[0107] [Substrate Thickness (mm)] The thickness of the substrate was measured with a dial thickness gauge at a portion of the molded surface fastener where no hook-type engaging elements were present. The thickness was calculated as the average value at 10 points.

[0108] [Processability] The processability when manufacturing molded hook-and-loop fasteners was evaluated according to the following criteria. (Injection molding type) A: Resin is filled up to the tip of the mold, and good hook moldability is achieved. B: There are some areas where hooks are not formed. C: Hooks are not formed. (Extrusion molding type) A: Sufficient cutting is possible in the hook cutting process, sufficient stretching is possible in the stretching process, and individual engaging elements are independent. B: Powdery material due to resin scraping adheres to the take-up roller during the process. C: Breaks during the hook cutting and stretching processes.

[0109] [Initial Engagement Force] (Loop Hook and Loop Fastener) A knitted female hook and loop fastener (E5000C manufactured by Kuraray Fastening Co., Ltd., basis weight: 190±10 g / m) was used, in which multifilament loops serving as loop-type engaging elements were formed on the surface of a tricot knitted fabric base fabric. ２ The molded hook-and-loop fasteners were used. The tensile shear strength and peel strength were measured in accordance with JIS L 3416 (2000). The overlapping area of ​​the hook and loop was measured in a 20 mm x 50 mm (10 cm) square. ２ ) and calculated as an average value in N / cm ２ The average value was calculated by converting the value into N / cm. The average shear value was the average value of the results of measurements made three times (N = 3). The average peel value was also the average value of the results of measurements made three times (N = 3). For the peel measurement results, the average value (N / 20 mm) was calculated with a measurement width of 20 mm, and this was then divided by 2 to convert to N / cm.

[0110] [Repeated engagement retention (engagement force after five peelings)] A molded hook-and-loop fastener was engaged with a knitted female hook-and-loop fastener (E5000C manufactured by Kuraray Fastening Co., Ltd.), and after five repeated manual peelings, the tensile shear strength and peel strength were measured. The engagement force was measured in the same manner as for the initial engagement force.

[0111] [Engagement force after being held under high temperature and high humidity] Using a thermo-hygrostat (ESPEC LHU-112M), the temperature was set to 65°C and the humidity was set to 80% RH, and the molded hook-and-loop fastener was left in this temperature and humidity atmosphere for 1 hour. In accordance with JIS L 3416 (2000), the tensile shear strength and peel strength with a knitted female hook-and-loop fastener (E5000C manufactured by Kuraray Fastening Co., Ltd.) were measured. The engagement force was measured using the same procedure as for the initial engagement force described above.

[0112] [Crack Resistance] When cracks occurred when the hook-and-loop fastener was bent at 90° parallel to the MD direction, the surface fastener was rated as C, and when no cracks occurred, the surface fastener was rated as A.

[0113] [Bleeding Resistance] A molded hook-and-loop fastener was cut into a size of 60 mm x 120 mm to prepare a sample, which was then vacuum-dried at 60°C for 8 hours and then weighed. A thermo-hygrostat (ESPEC PHP-2J) was used to create an environment of 65°C x 85% RH, and the sample was placed in the chamber. After leaving the sample for 30 days, the sample was removed and visually and tactilely inspected for bleedout. The sample was then washed with water and vacuum-dried at 60°C for 8 hours, after which the weight was measured. The amount of bleedout was calculated by calculating the weight loss from the weight before and after placement in the thermo-hygrostat, and the weight loss rate relative to the weight before placement in the thermo-hygrostat was calculated. The results of the visual and tactile evaluations and the weight loss rate were evaluated according to the following criteria. A: No bleedout was observed by visual inspection or tactile inspection, and the weight loss rate was less than 3.0%. B: No bleeding was observed by visual inspection and touch, but the weight loss rate was 3.0% or more. C: Bleeding was observed by visual inspection and touch.

[0114] [Biodegradability according to ISO 14851] In accordance with the biodegradability evaluation method described in ISO 14851, the substrate portion of the molded hook-and-loop fastener sample was cut into a length of 2 mm and a width of 2 mm and added to 300 mL of standard test culture medium containing activated sludge from a sewage treatment plant in Kurashiki City at a concentration of 100 mg / L, so that the concentration was 100 mg / L. This was cultured at 25±1°C, and the amount of oxygen consumed for biodegradation was measured using a BOD meter (WTW's "Oxitop"), and the biodegradability was calculated from the ratio of this value to the theoretical oxygen demand (ThOD), and biodegradability was judged according to the following criteria: A: Biodegradability after 3 days is 5% or more; C: Biodegradability after 3 days is less than 5%.

[0115] Example 1: Hardwood prehydrolyzed kraft pulp with an α-cellulose content of 98.4 wt% was disintegrated into a flocculent state using a disc refiner. 26.8 wt. parts of acetic acid were sprayed onto 100 wt. parts of the disintegrated pulp (moisture content: 8%), mixed thoroughly, and then allowed to stand for 60 hours for activation as a pretreatment. The activated pulp was added to a mixture of 323 wt. parts of acetic acid, 245 wt. parts of acetic anhydride, and 13.1 wt. parts of sulfuric acid, and the mixture was heated to a maximum temperature of 5-40°C over 40 minutes and then acetylated for 90 minutes. A neutralizer (24% aqueous magnesium acetate solution) was added over 3 minutes to adjust the amount of sulfuric acid (amount of aging sulfuric acid) to 2.5 wt. parts. The reaction bath was then heated to 75°C, and water was added to adjust the reaction bath moisture (aging moisture) to a concentration of 52 mol%. The mixture was then aged at 85°C, and the aging was stopped by neutralizing the sulfuric acid with magnesium acetate, yielding a reaction mixture containing cellulose acetate. A dilute aqueous solution of acetic acid was added to the resulting reaction mixture, and the cellulose acetate was separated. The resulting mixture was then washed with water, dried, and stabilized with calcium hydroxide to obtain cellulose acetate with an average acetyl substitution degree of 2.4 and a weight-average molecular weight of 180,000. The resulting cellulose acetate (70% by weight) and an adipate ester compound (manufactured by Daihachi Chemical Industry Co., Ltd., "DAIFATTY-101") (30% by weight) were added to a Henschel mixer and stirred to a temperature of 70°C or higher due to frictional heat within the mixer. The mixture was then fed into a twin-screw extruder (cylinder temperature: 200°C, die temperature: 210°C), extruded, and pelletized.

[0116] Using a nozzle having the same cross-sectional shape as that shown in Figure 5, the obtained cellulose acetate resin composition pellets were extruded at a nozzle temperature of 210°C and cooled to form a molded surface fastener precursor. The obtained molded surface fastener precursor had the shape shown in Figure 5, and specifically, on a substrate precursor (24) made of a cellulose acetate resin composition, rows (25) for hook-type engaging elements, each having two protrusions in the vertical direction, also made of a cellulose acetate resin composition, stood up. The width of the obtained molded surface fastener precursor was 40 mm. The molded surface fastener precursor had a plurality of rows for hook-type engaging elements on its surface that were continuous in the length direction of the tape (machine running direction). The number of rows for hook-type engaging elements was 5 per 1 cm of tape width.

[0117] Then, slits were made in the rows for the hook-type engaging elements at 0.5 mm intervals in a direction substantially perpendicular to the longitudinal direction of the rows, from the tip of the rows in the height direction to 4 / 5 of the height of the rows (1 / 5 from the bottom). Next, the molded surface fastener precursor was stretched 1.88 times in the longitudinal direction at a temperature of 130°C to produce a molded surface fastener.

[0118] The obtained hook-type molded surface fastener (30) had a substrate (31) and hook-type engaging elements (32) rising from its surface, as shown in Figure 6. The hook-type engaging elements (32) had stem portions (33) rising from the substrate, and protrusions (36) protruding from the middle of the stem portions in a direction approximately perpendicular to the row direction of the hook-type engaging elements and symmetrically from the stem portions. Furthermore, the tips of the protrusions (36) were close to the substrate surface, and there were two protrusions (36) present in the vertical direction on one side of the stem portions (33), so that one stem portion (33) had a total of four protrusions (36).

[0119] The thickness of the substrate of the molded surface fastener is 0.3 mm, and the height of the hook-type engaging element from the substrate surface (H ０The thickness of the hook-type engaging elements (in the extrusion direction of the molded surface fastener precursor [the row direction of the hook-type engaging elements]) was 2.4 mm, and the thickness of the hook-type engaging elements (in the extrusion direction of the molded surface fastener precursor [the row direction of the hook-type engaging elements]) was 0.54 mm. Furthermore, when the row direction of the hook-type engaging elements was used as a reference, the ratio of the spacing (mm) between the stem portions to the thickness (mm) of the stem portions was 0.61, and the density of the hook-type engaging elements in the portion where the hook-type engaging elements were present was 51.2 pieces / cm. 2 The molded surface fastener thus obtained was evaluated, and the results are shown in Table 1.

[0120] [Example 2] A molded surface fastener was produced in the same manner as in Example 1, except that the draw ratio was 2.25 times and the take-up speed was 4.73 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 1.

[0121] [Example 3] A molded surface fastener was produced in the same manner as in Example 1, except that the amount of cellulose acetate in Example 1 was changed to 80% by weight and the amount of adipic acid ester compound to 20% by weight, the nozzle temperature was set to 240°C, the stretching temperature to 150°C, the stretching ratio to 2.00, and the take-up speed to 4.20 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 1.

[0122] [Example 4] A molded surface fastener was produced in the same manner as in Example 1, except that the amount of cellulose acetate in Example 1 was changed to 55% by weight and the amount of adipic acid ester compound to 45% by weight, the stretching ratio was changed to 2.00, and the take-up speed was changed to 4.20 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 1.

[0123] [Example 5] A molded surface fastener was produced in the same manner as in Example 1, except that the draw ratio was set to 2.44 times and the take-up speed was set to 5.12 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 1.

[0124] [Example 6] [Preparation of molding die] The die used was a ring-shaped die having a thickness of 0.30 mm and a diameter of 212 mm, with the shape of the hook-type engagement element engraved on its outer circumference; a metal ring having a thickness of 0.30 mm and a diameter of 212 mm and a flat outer circumferential surface without such shapes engraved; a ring-shaped die having a thickness of 0.30 mm and a diameter of 212 mm, with the shape of the hook-type engagement element engraved on its outer circumference but facing in the opposite direction to the shape of the hook-type engagement element; and a metal ring having a thickness of 0.20 mm and a diameter of 212 mm and a flat outer circumferential surface without such shapes engraved. This successively stacked these elements to prepare a die roll having a width of 120 mm, the outer circumferential surface of which had a number of cavities in the shape of the hook-type engagement element and cavities in the shape of the hook-type engagement element facing in the opposite direction.

[0125] [Production of Hook-Type Molded Surface Fastener] A melt of the cellulose acetate resin composition pellets used in Example 1 (melting temperature: 210°C) was extruded into the gap between the mold roll and another drum roll located opposite the mold roll, and the resin composition was filled into the cavity by compression, forming a sheet of uniform thickness on the roll surface. While the mold roll was rotating, the resin composition in the cavity was cooled by water constantly circulating inside the roll, and then the sheet was stretched using nip rolls with the gap adjusted to a substrate thickness of 0.20 mm, and the cooled and solidified sheet was peeled off from the mold roll surface (surface temperature: 100°C), producing a hook-type molded surface fastener. The obtained molded surface fastener was evaluated, and the results are shown in Table 2.

[0126] [Example 7] A molded surface fastener was produced in the same manner as in Example 6, except that the pellets in Example 1 were prepared by changing the amount of cellulose acetate to 75% by weight and the amount of adipic acid ester compound to 25% by weight, the melting temperature was set to 230°C, the surface temperature of the mold roll to 110°C, and the take-up speed to 15.3 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 2.

[0127] [Example 8] A molded surface fastener was produced in the same manner as in Example 6, except that the pellets in Example 1 were prepared by changing the amount of cellulose acetate to 80% by weight and the amount of adipic acid ester compound to 20% by weight, the melting temperature was set to 240°C, the surface temperature of the mold roll to 115°C, and the take-up speed to 15.6 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 2.

[0128] [Example 9] A molded surface fastener was produced in the same manner as in Example 6, except that the amount of cellulose acetate in Example 1 was changed to 55% by weight, the amount of adipic acid ester compound was changed to 45% by weight, and the take-up speed was changed to 13.6 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 2.

[0129] [Example 10] A molded surface fastener was produced in the same manner as in Example 6, except that the pellets in Example 1, in which the amount of cellulose acetate was changed to 94% by weight and the amount of adipic acid ester compound was changed to 6% by weight, the melting temperature was set to 240°C, the surface temperature of the mold roll was set to 125°C, and the take-up speed was set to 14.6 m / min. The obtained molded surface fastener was evaluated, and the results are shown in Table 2.

[0130] Comparative Example 1 A molded surface fastener was produced in the same manner as in Example 1, except that the stretch ratio was 2.65 times and the take-up speed was 5.57 m / min. The obtained molded surface fastener was evaluated. The stretch ratio was high, the orientation degree was 0.410, and the strain was 2.20%, and although molding was possible and the initial engaging force was good, the tape was brittle, cracking occurred in the MD direction, the engaging force had poor peel durability, and the biodegradability was poor. The results are shown in Table 1.

[0131] Comparative Example 2 An attempt was made to produce a molded hook-and-loop fastener in the same manner as in Example 1, except that the pellets in Example 1 were changed so that the amount of cellulose acetate was 95% by weight and the amount of adipic acid ester compound was 5% by weight, and the stretching temperature was 150°C, the stretching ratio was 2.00 times, and the take-up speed was 4.20 m / min. However, the obtained molded hook-and-loop fastener had many cracked engaging elements, parts that were not hook-shaped, and parts where the engaging elements themselves were damaged and absent, and therefore had no engaging force, so no subsequent evaluation of engaging force was made.

[0132] [Comparative Example 3] A molded surface fastener was produced in the same manner as in Example 6, except that the surface temperature of the mold roll was set to 76°C and the take-up speed was set to 5.4 m / min. However, the resulting molded surface fastener had no engaging force due to damage to the engaging elements, so no subsequent evaluation of the engaging force was performed.

[0133] [Comparative Example 4] A molded surface fastener was produced in the same manner as in Example 6, except that the surface temperature of the mold roll was set to 83°C and the take-up speed was set to 14.9 m / min. However, the resulting molded surface fastener had no engaging force due to damage to the engaging elements, so no subsequent evaluation of the engaging force was performed.

[0134] Comparative Example 5 A molded surface fastener was produced in the same manner as in Example 6, except that the pellets used in Example 1 were modified so that the amount of cellulose acetate was 75% by weight and the amount of adipic acid ester compound was 25% by weight, the melting temperature was 230°C, the surface temperature of the mold roll was 85°C, and the take-up speed was 15.4 m / min. The obtained molded surface fastener was evaluated. The orientation degree was 0.402, and molding was possible, but the material was brittle, causing cracks in the MD direction, and biodegradability was poor. The results are shown in Table 2.

[0135] Comparative Example 6 A molded surface fastener was produced in the same manner as in Example 6, except that the pellets used in Example 1 were modified so that the amount of cellulose acetate was 80% by weight and the amount of adipic acid ester compound was 20% by weight, the melting temperature was 240°C, the surface temperature of the mold roll was 90°C, and the take-up speed was 15.4 m / min. The obtained molded surface fastener was evaluated. The orientation degree was 0.411, and molding was possible, but the material was brittle, causing cracks in the MD direction, and biodegradability was poor. The results are shown in Table 2.

[0136] [Comparative Example 7] A molded surface fastener was produced in the same manner as in Example 6, except that the pellets used in Example 1 were changed so that the amount of cellulose acetate was 53% by weight and the amount of adipic acid ester compound was 47% by weight, the melting temperature was 205°C, the surface temperature of the mold roll was 80°C, and the take-up speed was 7.3 m / min. However, the engaging elements of the obtained molded surface fastener were damaged and the fastener had no engaging force, so subsequent evaluation of the engaging force was not performed. Furthermore, because the amount of plasticizer was large, bleeding was confirmed in the test to evaluate bleed-out resistance.

[0137] [Comparative Example 8] A molded surface fastener was produced in the same manner as in Example 6, except that the pellets in Example 1 were changed to contain 95% by weight of cellulose acetate and 5% by weight of adipic acid ester compound, the melting temperature was set to 240°C, the surface temperature of the mold roll was set to 95°C, and the take-up speed was set to 5.5 m / min. However, the obtained molded surface fastener had no engaging force because the engaging elements were broken, so no subsequent evaluation of engaging force was carried out. In addition, the orientation degree was 0.433, and because it was brittle, cracks occurred in the MD direction, and it was poor in biodegradability.

[0138]

[0139]

[0140] As shown in Tables 1 and 2, the orientation degrees of the molded surface fasteners of Examples 1 to 10 ranged from 0.135 to 0.382, and these Examples possessed biodegradability based on ISO 14851, with biodegradation progressing rapidly in a short period of time despite being in a low-enzyme environment of around 25° C. Furthermore, ISO 14851 confirms biodegradability at the low temperatures (around 25° C.) used for biodegradation in the ocean, and therefore these Examples, which exhibited rapid biodegradability in a low-temperature, low-enzyme environment, are predicted to have excellent biodegradability even in the ocean.

[0141] Furthermore, in Examples 1 to 3 and 6 to 8, the engaging force was maintained even after being kept under high temperature and high humidity conditions, and in Examples 1, 2 and 6 to 8, good repeated engagement retention was achieved.

[0142] Furthermore, the molded surface fasteners of Examples 1 to 10 can be suitably used as a surface fastener stack in combination with other surface fasteners (preferably biodegradable surface fasteners, more preferably the molded surface fasteners of the present disclosure).

[0143] On the other hand, in Comparative Example 1, where the degree of orientation is 0.410, although pellets made of the same resin composition as in Example 1 are used, the biodegradability based on ISO 14851 is not good. Furthermore, in Comparative Example 1, the substrate portion is more brittle than in Example 1, possibly due to the higher degree of orientation, and the engaging force under high temperature and high humidity conditions and the durability against repeated engaging are also reduced.

[0144] Furthermore, in Comparative Example 5, which has an orientation degree of 0.402, and Comparative Example 6, which has an orientation degree of 0.411, although pellets made of the same resin composition as in Examples 7 and 8 were used, the biodegradability based on ISO 14851 was not good. Furthermore, in Comparative Examples 5 and 6, the substrate portion became brittle, possibly due to the high orientation degree, and the engaging force after storage at high temperature and high humidity and the repeated engaging retention were also reduced.

[0145] In Comparative Examples 2 to 4, 7 and 8, as mentioned above, it was not possible to produce products with an engaging force sufficient for use as a molded surface fastener, and therefore no further evaluation was carried out.

[0146] The molded surface fastener of the present disclosure has excellent biodegradability and can therefore be suitably used in many applications, including agricultural materials, forestry materials, fisheries materials, civil engineering materials, clothing materials, daily necessities, sanitary materials, medical materials, and the like.

[0147] Although the preferred embodiments of the present disclosure have been described above, those skilled in the art will readily envision various changes and modifications within the scope of the present disclosure upon reading the present specification. Accordingly, such changes and modifications are to be interpreted as falling within the scope of the invention as defined by the claims.

[0148] DESCRIPTION OF SYMBOLS 10, 30: Molded surface fastener 11, 31: Substrate 12: Hook-type engaging element 20: Molded surface fastener precursor 24: Substrate precursor 25: Row for hook-type engaging element 33: Stem portion 36: Projection portion 38: Ridge portion

Claims

1. A molded surface fastener having a substrate having a first surface and a second surface, and hook-type engaging elements protruding from at least one of the surfaces, wherein the substrate and the hook-type engaging elements are both made of a cellulose ester resin composition, the cellulose resin composition contains a cellulose ester and an adipic acid ester compound in a weight ratio of cellulose ester / adipic acid ester compound of 94 / 6 to 55 / 45, and the orientation degree of the substrate in the machine direction is 0.120 to 0.

390.

2. The molded surface fastener according to claim 1, wherein the strain of the substrate in the machine direction is 2.5 to 15.0%.

3. The molded surface fastener according to claim 1, wherein the cellulose ester is cellulose acetate having an average degree of substitution of 2.0 to 2.

6.

4. The molded surface fastener according to claim 1, wherein the cellulose ester is cellulose acetate, the weight average molecular weight (Mw) of which is 100,000 to 1,000,000.

5. The molded surface fastener of claim 1, wherein the molded surface fastener is amorphous.

6. A hook-and-loop fastener stack made up of multiple hook-and-loop fasteners, in which a substrate or base fabric of another hook-and-loop fastener is joined to a substrate of a molded hook-and-loop fastener described in any one of claims 1 to 5, and the hook-and-loop fastener stack has engaging elements of the molded hook-and-loop fastener on one side and hook-type engaging elements or loop-type engaging elements of the other hook-and-loop fastener on the other side.

7. A hook-and-loop fastener stack composed of a plurality of hook-and-loop fasteners, in which the substrate of one molded hook-and-loop fastener is joined to the substrate of another molded hook-and-loop fastener, and all of the molded hook-and-loop fasteners in the hook-and-loop fastener stack are composed of the molded hook-and-loop fasteners described in any one of claims 1 to 5.

8. A method for producing a molded surface fastener according to any one of claims 1 to 5, comprising the steps of: pouring a melt of a cellulose ester resin composition onto the surface of a metal roll having perforated cavities, forcing the melt into the cavities, and forming a sheet of the melt onto the surface of the metal roll; and peeling the sheet from the surface of the metal roll to obtain a molded surface fastener comprising a substrate having a first surface and a second surface, and hook-type engaging elements or precursors thereof protruding from at least one of the surfaces.

9. A method for producing a molded surface fastener according to any one of claims 1 to 5, comprising the steps of: melt-extruding a cellulose ester resin composition through a slit having a predetermined shape to obtain a substrate precursor and a molded surface fastener precursor comprising a plurality of rows for engaging elements protruding from one side of the substrate precursor; making a plurality of small slits in the rows for engaging elements in the row direction from the tip of the rows toward the substrate precursor to a predetermined position on the rows; and stretching the molded surface fastener precursor in the row direction to widen the slit spacing, thereby obtaining a molded surface fastener comprising a substrate having a first side and a second side, and hook-type engaging elements protruding from at least one side of the rows.

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