CN116209368A

CN116209368A - Joint structure

Info

Publication number: CN116209368A
Application number: CN202180060979.XA
Authority: CN
Inventors: 大和亮介; 齐藤晃一; 小宫聪一郎; 久野和树; 末梨佳
Original assignee: Lishennoco Co ltd
Current assignee: Lishennoco Co ltd
Priority date: 2020-09-28
Filing date: 2021-09-27
Publication date: 2023-06-02
Also published as: WO2022065488A1; JPWO2022065488A1; TW202222190A

Abstract

The invention provides a joint structure (1) which is formed by jointing stretchable materials (2, 2) through bonding parts (3) with a prescribed pattern, wherein the bonding parts (3) are based on the extending shaft (P) along the stretching direction (T1) of the stretchable material (2) to extend in a dotted line shape as a whole, and each dotted line part (5) of the bonding parts (3) is intersected with the extending shaft (P).

Description

Joint structure

Technical Field

The present invention relates to a joining structure.

Background

As a conventional joining structure, there is a method of attaching an elastic material described in patent document 1, for example. The conventional bonding structure is a structure in which stretchable materials are bonded to each other by an adhesive (adhesive) in a prescribed bonding pattern. The bonding pattern has bonding portions that continuously bond the stretchable materials to each other. The adhesive portion is continuously provided in the edge direction of the stretchable material by a pattern such as a zigzag shape.

Technical literature of the prior art

Patent literature

Patent document 1: japanese patent laid-open No. 2004-11056

Disclosure of Invention

Technical problem to be solved by the invention

In the above-described joining structure, it is necessary to ensure sufficient joining strength without impairing the stretchability of the stretchable material to be joined. Further, from the viewpoint of cost reduction of the bonding structure, it is desirable to reduce the amount of adhesive required for bonding.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a joining structure capable of sufficiently securing both stretchability and joining strength of a stretchable material while reducing the amount of an adhesive used.

Means for solving the technical problems

The joining structure according to one aspect of the present invention is formed by joining stretchable materials to each other by means of a predetermined pattern of adhesive portions, wherein the adhesive portions are integrally extended in a broken line shape based on an extension axis along the stretching direction of the stretchable materials, and the broken line portions of the adhesive portions intersect with respect to the extension axis.

In this joint structure, the joint structure extends in a broken line based on an extension axis along the expansion and contraction direction of the stretchable material as a whole. Therefore, the bonded portions and the non-bonded portions are alternately arranged with respect to the expansion and contraction direction of the stretchable material. Since the non-bonded portion where the bonded portion is not present serves as an extension margin of the stretchable material, stretchability of the stretchable material can be sufficiently ensured. In the joining structure, the respective broken line portions of the bonded portions intersect with each other about the extension axis. Therefore, the regions where the bonded portions and the non-bonded portions are alternately arranged are formed with a constant width in the direction intersecting the stretching direction of the stretchable material, and the joining hardness of the stretchable material can be sufficiently ensured. The adhesive portion is in a broken line shape, so that the amount of the adhesive used is reduced as compared with the case where the adhesive portion is continuously provided.

In the bonding portion, the positions of the groups of the broken line portions adjacent in the extending axis direction may be reversed with respect to the extending axis. In this case, the arrangement of the bonded portions is symmetrical with respect to the extension axis, so that it is possible to suppress variation in stretchability and bonding strength in the region where the bonded portions and the non-bonded portions are alternately arranged.

In the bonding portion, positions of the broken line portions adjacent to each other in the extending axis direction may be reversed with respect to the extending axis. In this case, the arrangement of the bonded portions is symmetrical with respect to the extension axis, so that it is possible to suppress variation in stretchability and bonding strength in the region where the bonded portions and the non-bonded portions are alternately arranged.

Each of the broken line portions of the adhesion portion may extend in a direction orthogonal to the extension axis. In this case, the joining hardness of the stretchable material can be further sufficiently ensured.

The bonding portion may have a saw tooth shape as a whole. Thus, the bonded portion satisfying the above structure can be formed simply.

The adhesive portion may be constituted by a hot melt adhesive. The hot melt adhesive is solvent-free adhesive and has the advantage of small load on the environment and human body. In addition, the bonding can be performed in a short time, thereby contributing to an improvement in productivity of the bonded structure.

Effects of the invention

According to the present invention, the amount of the adhesive used can be reduced, and both the stretchability and the bonding strength of the stretchable material can be sufficiently ensured.

Drawings

Fig. 1 is a cross-sectional view showing a joint structure according to one aspect of the present invention.

Fig. 2 is a plan view showing an example of a pattern of an adhesive portion.

Fig. 3 is a plan view showing another example of the pattern of the bonded portion.

Fig. 4 is a plan view showing another example of the pattern of the bonded portion.

Fig. 5 is a plan view showing the structure of a sample in the stretchability evaluation.

Fig. 6 is a graph showing evaluation test results of stretchability and adhesive strength in each pattern of an adhesive portion.

Detailed Description

Hereinafter, preferred embodiments of the joining structure according to one aspect of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, the numerical range indicated by the term "to" includes numerical values before and after the term "to" as a minimum value and a maximum value, respectively.

[ Joint Structure ]

Fig. 1 is a cross-sectional view showing a joint structure according to one aspect of the present invention. As shown in fig. 1, the joining structure 1 is a structure in which a pair of

stretchable materials

2 and 2 are joined by an adhesive portion 3. Here, the stretchable material 2 is, for example, stretchable cloth used for casual wear, underwear, or the like. As the stretchable fabric, a stretchable knitted fabric or a stretchable woven fabric can be used. Examples of the material of the stretchable fabric include polyester, polyurethane, acrylic, cotton, nylon, and a composite fabric obtained by compositing these materials. The

stretchable materials

2 and 2 may be the same material or may be different materials.

One direction of the plane direction of the stretchable material 2 is the stretching direction T1 of the stretchable material 2. The degree of stretchability of the stretchable material 2 in the stretch direction T1 is not particularly limited, and any stretchability may be used. The stretchable material 2 may have stretchability in a plurality of directions in the planar direction of the stretchable material 2. In this case, one of the directions is defined as the expansion and contraction direction T1.

The adhesive portion 3 is made of, for example, a hot melt adhesive, and is disposed between the

stretchable materials

2 and 2 in a predetermined pattern. The joining of the

stretchable materials

2, 2 is performed by the adhesive portion 3. In the seamless joining, no suture is used, and therefore stretchability in the joined portion is easily ensured. Further, since loosening or the like of the cloth by the stitch is not generated, the beauty of the joined portion is easily maintained as compared with joining by sewing. In the bonding using the hot-melt adhesive, in addition to the case where the bonded portion is easily applied to bending, the bonding structure 1 after bonding can be improved in reliability because high pressure does not need to be applied at the time of bonding, as compared with the bonding using the conventional adhesive tape.

[ Hot melt adhesive ]

The hot melt adhesive is, for example, a moisture-curable hot melt adhesive containing a polyurethane prepolymer. In general, a moisture curable hot melt adhesive can be increased in molecular weight by chemical reaction and exhibit adhesive force and the like. The polyurethane prepolymer having isocyanate groups is cured by reacting with moisture. Therefore, the moisture curable hot melt adhesive may be composed of a polyurethane prepolymer alone, or may contain an additive or the like used in the field of moisture curable hot melt adhesives in addition to the polyurethane prepolymer.

Polyurethane prepolymers are for example reactants of polyols and polyisocyanates. The polyurethane prepolymer may be, for example, a polyurethane prepolymer having isocyanate groups. Polyurethane prepolymers having isocyanate groups generally have a polymeric chain and isocyanate groups containing structural units derived from a polyol (a compound having 2 or more hydroxyl groups in the molecule) and structural units derived from a polyisocyanate (a compound having 2 or more isocyanate groups in the molecule). The isocyanate groups may be bonded to the ends of the polymeric chains.

The composition and the like of the polyurethane prepolymer can be changed by changing the type and content of the polyol to which the structural unit derived from the polyol is added and the type and content of the polyisocyanate to which the structural unit derived from the polyisocyanate is added. The urethane bond is formed by reacting a polyol and a polyisocyanate, so that the polymeric chain of the polyurethane prepolymer has a urethane bond. By increasing the ratio of the equivalent weight of the polyisocyanate to the equivalent weight of the polyol, an isocyanate group can be introduced at the end of the polymer chain.

[ Pattern of bonded portion ]

Fig. 2 is a plan view showing an example of a pattern of an adhesive portion. In fig. 2, the stretching direction T1 of the stretchable material 2 is set in the up-down direction of the drawing. For convenience of explanation, one of the stretchable materials 2 is illustrated, and the other stretchable material 2 is omitted.

The bonded portion 3A shown in fig. 2 extends in a broken line based on an extension axis P along the stretching direction T1 of the stretchable material 2. More specifically, the adhesion portion 3A has a plurality of broken line portions 5. The broken line portions 5 are each formed in a band shape having a width of about 0.1mm to 50mm, for example. The width of the broken line portion 5 may be 0.5mm to 2.5mm or 1.0mm to 5.0mm. The width of the broken line portion 5 can be set in consideration of, for example, the range that can be applied by the dispenser. The adhesion portion 3A is arranged with these broken line portions 5 on a line L of saw teeth centering on the extension axis P, thereby having a saw tooth shape as a whole.

In the line L, the positions of the groups of the broken line portions 5 adjacent in the extending axis P direction are reversed with respect to the extending axis P. In the example of fig. 2, a group of 2 broken line portions 5 is formed of the broken line portions 5. One of the groups 6A of the broken line portions 5 adjacent in the extending axis P direction extends in a direction connecting the lower right of the drawing plane and the upper left of the drawing plane of fig. 2. The other group 6B of the broken line portions 5 adjacent in the extending axis P direction extends in the direction connecting the upper right and lower left of the drawing plane of fig. 2.

The dashed portions 5 on the line L intersect with respect to the extension axis P, respectively. The intersection angle θ between the dashed line portion 5 and the extension axis P is, for example, about 5 ° to 85 °. The intersection angle θ between the dashed line portion 5 and the extension axis P may be 20 ° to 80 °, or 40 ° to 70 °.

[ Effect of the invention ]

As described above, in the joining structure 1, the adhesive portion 3A extends in a broken line and in a zigzag shape based on the extension axis P along the extension and contraction direction of the

stretchable materials

2, 2 as a whole. Therefore, in the joining structure 1, as shown in fig. 2, the regions 10 in which the bonded portions 3 and the non-bonded portions 7 are alternately arranged with respect to the expansion and contraction direction T1 of the stretchable material 2 are formed along the extension axis P. In the region 10, the non-bonded portion 7 of the bonded portion 3 is not present and becomes an extension margin of the stretchable material 2 with respect to the stretching direction T1, so that the stretchability of the stretchable material 2 can be sufficiently ensured.

In the joining structure 1, the respective broken line portions 5 of the bonded portion 3A intersect with the extension axis P at an intersection angle θ. Therefore, the regions 10 where the bonded portions 3A and the non-bonded portions 7 are alternately arranged are formed with a constant width R in the direction T2 orthogonal to the expansion and contraction direction T1 of the stretchable material 2, and the joining hardness of the stretchable material 2 can be sufficiently ensured. In the example of fig. 2, the width R of the region 10 corresponds to the distance between the points 5a, which become peaks of the amplitude of the saw-tooth in the bonded portion 3A, in the direction T2 orthogonal to the expansion and contraction direction T1.

In the joining structure 1, the adhesive portion 3A is formed in a virtual line shape by the plurality of broken line portions 5, and therefore, the amount of the adhesive used is reduced as compared with the case where the adhesive portion is continuously provided. The reduction in the amount of the adhesive used and the adhesive strength of the

stretchable materials

2, 2 are in a trade-off relationship. In the case where the reduction in the amount of the adhesive to be used is prioritized, for example, the pitch of the serrations of the line L may be increased or the length or width of each of the broken line portions 5 may be reduced. In the case of giving priority to the adhesive strength of the

stretchable materials

2 and 2, for example, the pitch of the serrations of the lines L may be reduced or the length or width of each of the broken line portions 5 may be increased.

[ another example of an adhesion pattern ]

Fig. 3 is a plan view showing another example of the pattern of the bonded portion. The bonded portion 3B shown in fig. 3 is in a broken line shape and a zigzag shape as a whole, which is the same as the bonded portion 3A, but the structure of each broken line portion 5 is different from the bonded portion 3A. Specifically, in the bonded portion 3B, each of the broken line portions 5 arranged on the zigzag line L extends in a direction intersecting (here, orthogonal to) the extension axis P.

The positions of the adjacent

broken line portions

5A, 5B in the extending axis P direction are reversed with respect to the extending axis P. One of the imaginary line portions 5A adjacent in the extending axis P direction extends from a position overlapping the extending axis P to one side (right side in the drawing in fig. 3) of the extending axis P. The other broken line portion 5B adjacent in the extending axis P direction extends from a position overlapping the extending axis P to the other side (left side of the drawing in fig. 3) of the extending axis P.

The intersection angle θ between the

imaginary line parts

5A and 5B and the extension axis P (here, the intersection angle between the line L on which the

imaginary line parts

5A and 5B are arranged and the extension axis P) is, for example, about 5 ° to 85 °. The intersection angle θ between the dashed line portion 5 and the extension axis P may be 20 ° to 80 °, or 40 ° to 70 °.

The arrangement interval of the

imaginary line parts

5A, 5B in the direction of the extension axis P is not particularly limited, but in the example of fig. 3, the

imaginary line parts

5A, 5B are arranged at intervals of the same extent as the width of the

imaginary line parts

5A, 5B in the direction of the extension axis P. That is, the non-bonded portion 7 is present between the

broken line portions

5A, 5B with a width equal to the width in the extending axis P direction in the

broken line portions

5A, 5B.

The adhesive portion 3B also functions in the same manner as the adhesive portion 3A described above, and can sufficiently ensure both stretchability and bonding strength of the stretchable material 2 while reducing the amount of adhesive used. In the bonded portion 3B, the width R of the region 10 in which the bonded portion 3 and the non-bonded portion 7 are alternately arranged corresponds to the distance between the edge 5B on one side of the extension axis P in the broken line portion 5A and the edge 5B on the other side of the extension axis P in the broken line portion 5B in the direction T2 orthogonal to the expansion and contraction direction T1.

Fig. 4 is a plan view showing another example of the pattern of the bonded portion. The bonding portion 3C shown in fig. 4 is different from the bonding portion 3A in that it has a plurality of broken linear and zigzag lines L. Specifically, the bonding portion 3C has 2 lines L1, L2 which are dotted and zigzag. These 2 lines L1, L2 are mutually inverted with respect to the extension axis P.

In each line L1, L2, the repeated pitch of the serrations is constituted by 1 broken line portion 5. The broken line portions 5 intersect the extension axis P similarly to the bonded portions 3A. The intersection angle θ between the dashed line portion 5 and the extension axis P is, for example, about 5 ° to 85 °. The intersection angle θ between the dashed line portion 5 and the extension axis P may be 20 ° to 80 °, or 40 ° to 70 °.

In each line L1, L2, positions of the

imaginary line portions

5A, 5B adjacent to each other in the extending axis P direction are reversed with respect to the extending axis P. In the example of fig. 4, one of the broken line portions 5A adjacent in the extending axis P direction extends in a direction connecting the lower right of the drawing plane and the upper left of the drawing plane of fig. 4. The other broken line portion 5B adjacent in the extending axis P direction extends in a direction connecting the upper right and lower left of the drawing plane of fig. 4.

The dashed

lines

5A and 5B adjacent to each other in the extending axis P direction are separated from each other at positions corresponding to peaks of amplitudes of the saw teeth. On the other hand, at the position of the extension axis P, the edge of the broken line portion 5A of one line L1 and the edge of the broken line portion 5B of the other line L2 are connected. In addition, at the position of the extension axis P, the edge of the broken line portion 5B of one line L1 and the edge of the broken line portion 5A of the other line L2 are connected.

Accordingly, the

broken line portions

5A and 5B arranged in zigzag on the 2 lines L1 and L2 can be regarded as a pattern in which the V-shaped broken line portions 5 are alternately inverted in the extending axis P direction. In the bonded portion 3C, the width R of the region 10 in which the bonded portion 3 and the non-bonded portion 7 are alternately arranged corresponds to the distance between the end points 5C, 5C in the direction T2 orthogonal to the expansion and contraction direction T1 in the V-shaped broken line portion 5. The adhesive portion 3C also plays the same role as the adhesive portion 3A described above, and can sufficiently ensure both stretchability and bonding strength of the stretchable material 2 while reducing the amount of adhesive used.

In fig. 2 to 4, the structure in which the broken line portions 5 are arranged on the line L of the saw teeth is illustrated, but the pattern of the adhesion portion is not limited thereto. The line in which the broken line portions are arranged may have other shapes such as a wave shape, a sine wave shape, a rectangular wave shape, and the like. The shape of the broken line portion is not limited to a band shape, and may take other shapes such as an arc shape, an L-shape, an elliptical shape, and an oblong shape, depending on the shape of the line.

[ test for confirming effect of bonded portion ]

Next, an effect confirmation test of the bonded portion will be described. The test uses the adhesive portions of the respective patterns according to examples and comparative examples to bond stretchable materials to each other and measures the stretchability and bonding strength of the obtained bonded structure.

(preparation of moisture-curable Hot melt adhesive)

An aromatic ring-free amorphous polyester polyol (hydroxyl number: 2, number average molecular weight: 5000) containing dicarboxylic acid (adipic acid and isophthalic acid) and diol (ethylene glycol and neopentyl glycol) as main components, an aromatic ring-containing amorphous polyether polyol (hydroxyl number: 2, number average molecular weight: 2000), an aromatic ring-containing amorphous polyether polyol (bisphenol A. PO system, hydroxyl number: 2, number average molecular weight: 360) and 16 parts by mass of an aromatic ring-free amorphous polyester polyol (hydroxyl number: 2, number average molecular weight: 5000) containing dicarboxylic acid (adipic acid) and diol (neopentyl glycol and 1, 4-butanediol) as main components were dehydrated in advance by a vacuum dryer. Diphenylmethane diisocyanate (product name: MILLIONATE MT, number of isocyanate groups: 2) was added to the reaction vessel so that the equivalent ratio of isocyanate groups of the polyisocyanate to hydroxyl groups of the polyol ((NCO) equivalent/(OH equivalent)) was 1.8, and mixed at 110℃for 1 hour until uniformity was obtained. This was stirred at 110℃for 1 hour under vacuum degassing, whereby a polyurethane prepolymer was obtained. The polyurethane prepolymer obtained was used as a moisture-curable hot-melt adhesive.

In the production of each sample of examples and comparative examples, a moisture-curable hot-melt adhesive melted at 100℃was applied to a stretchable fabric in a predetermined pattern using a non-contact JET dispenser (manufactured by Musashi engineering. Inc.: IMAGE MASTER PC Smart), and an adhesive portion was formed. The outer diameter of the nozzle used for the application of the adhesive was set to 18G, and the application pressure was set to 150kPa. Next, the same stretchable cloth was placed on the formed bonded portion, and the bonded body was obtained by crimping at a temperature of 100 ℃. The above-mentioned pressure-bonded body was allowed to stand in a constant temperature bath at 23℃and 50% RH for 3 days or more, and the adhesive was cured, whereby a bonded structure was obtained.

The stretchability was evaluated in accordance with JIS-L1096 (A method) using the elongation of the joint structure as an index. A tensile tester (Shimadzu Corporation: EZ-test) was used for the evaluation. The samples of examples and comparative examples were set in a tensile tester, and each sample was elongated at a measurement temperature of 25℃and a tensile speed of 300mm/min, and after a load of 14.7N was applied, the load was released.

Fig. 5 is a plan view showing the structure of a sample in the stretchability evaluation. As shown in fig. 5, in each sample S of the examples and comparative examples, a stretchable cloth 11 having a rectangular shape was used, and a stretchable direction T1 was set in a direction connecting short sides. The length of the short side a of the stretchable fabric 11 was 20mm, and the length of the long side B was 150mm. The length C in the expansion and contraction direction T1 of the region 12 forming the pattern of the bonded portion was set to 100mm, and the width (length in the direction orthogonal to the expansion and contraction direction T1) D was set to 9mm. The width D corresponds to the width R of the region 10 in which the bonded portions 3 and the unbonded portions 7 are alternately arranged as shown in fig. 2 to 4.

In each sample S, the grip portions 13 based on the tensile tester were set at both end portions in the expansion and contraction direction T1. The length E of the collet section 13 in the expansion and contraction direction T1 is set to 25mm. The distance between the chucks is set to be 100mm equal to the length C in the expansion and contraction direction T1 of the region 10 where the bonded portion is formed. The elongation (%) of each sample was calculated by the following formula.

Elongation (%) = (elongation (mm) in a state where a load of 14.7N is applied)/distance between chucks (mm)) ×100

The adhesion strength was evaluated by using a tensile tester (manufactured by Shimadzu Corporation: EZ-Test EZ-SX). The samples of examples and comparative examples were each set in a tensile tester, and the test was performed at a measurement temperature of 25℃and a tensile speed of 100mm/min according to the T-peel strength test, and the measurement results were used as adhesive strength.

Fig. 6 is a graph showing evaluation test results of stretchability and adhesive strength in each pattern of an adhesive portion. As shown in fig. 6, embodiment 1 is the same pattern as the bonding portion 3 shown in fig. 2, and embodiment 2 is the same pattern as the bonding portion 3 shown in fig. 3. Embodiment 3 is the same pattern as the adhesive portion 3 shown in fig. 4. Comparative example 1 is a pattern in which no adhesive portion is provided, and comparative example 2 is a pattern in which 4 adhesive portions in a continuous straight line are provided separately from each other in the width D direction.

As shown in fig. 6, in comparative example 1, the elongation was 247%. That is, the original elongation of the stretchable fabric 11 in the state where the bonded portion is not provided was 247%. In comparative example 2, the adhesive strength was 10N/9mm and the elongation was 146%. In contrast, in example 1, the adhesive strength was 5N/9mm, the elongation was 233%, and in example 2, the adhesive strength was 9N/9mm, the elongation was 200%. In example 3, the adhesive strength was 5N/9mm and the elongation was 209%.

From these results, it was found that in examples 1 to 3, the adhesive strength of 5N/9mm or more was obtained, and the adhesive strength was ensured at a level comparable to that of comparative example 2 in which 4 continuous linear adhesive portions were provided. In particular, in example 2, the adhesive strength was 9N/9mm, and it was found that the adhesive strength was almost the same as that of comparative example 2.

Further, it was found that in examples 1 to 3, an elongation of 200% or more was obtained, and stretchability was ensured at a level comparable to that of comparative example 1 in which no adhesive portion was provided. In particular, in example 1, the elongation was 233%, and it was found that almost the same elongation as in comparative example 1 was obtained. From the above results, it was confirmed that both the stretchability and the bonding strength of the stretchable material can be sufficiently ensured by adopting the bonding structure of the present invention.

The amounts of moisture curable hot melt adhesives used in examples 1 to 3 and comparative example 2 are also shown in FIG. 6. In comparative example 2 in which 4 continuous linear adhesive portions were provided, the amount of the adhesive used was 0.17g. In contrast, in examples 1 to 3 in which the adhesive portions having a broken line shape and a zigzag shape were provided, the amounts of the adhesives used were 0.019g, 0.065g and 0.060g, respectively. Therefore, it was confirmed that the amount of the adhesive used in examples 1 to 3 was reduced by about 1/10 to 1/3 relative to comparative example 2.

Symbol description

1-joining structure, 2-stretchable material, 3 (3A-3C) -adhesive portion, 5 (5A, 5B) -broken line portion, 6-broken line portion group, P-extension shaft, T1-stretching direction.

Claims

1. A joining structure in which stretchable materials are joined to each other by an adhesive portion of a prescribed pattern,

the adhesive portion extends in a broken line based on an extending axis along the extending direction of the stretchable material as a whole,

each of the broken line portions of the bonding portion intersects with respect to the extension axis.

2. The joint structure according to claim 1, wherein,

in the bonding portion, positions of groups of the broken line portions adjacent in the extending axis direction are reversed with respect to the extending axis.

3. The joint structure according to claim 1, wherein,

in the adhesion portion, positions of the broken line portions adjacent to each other in the extending axis direction are reversed with respect to the extending axis.

4. The joining structure according to any one of claims 1 to 3, wherein,

the respective broken line portions of the adhesion portion extend in a direction orthogonal to the extension axis.

5. The joining structure according to any one of claims 1 to 4, wherein,

the bonding portion has a saw tooth shape as a whole.

6. The joining structure according to any one of claims 1 to 5, wherein,

the bonding part is composed of hot melt adhesive.