JP3140602B2 - Manufacturing method of cushion sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion sheet, and more particularly, to a method for manufacturing a cushion sheet such as a heel pad for incorporation into athletic shoes or the like.

[0002]

2. Description of the Related Art Conventionally, as a heel pad, as shown in FIG. 7, a plate-shaped elastic polymer foam having a relatively low density, for example, an upper layer 1 formed of an elastic polyurethane foam into a desired shape, is used. For example, there is a composite laminate obtained by casting a relatively high-density plate-like viscoelastic polyurethane known as a trade name "Sorboscein" into a shape conforming to the desired shape and pressing the lower layer by pressure. . Viscoelastic polyurethanes are characterized in that they have an excellent original recovery power and a large ability to absorb impact energy. For example, Japanese Patent Application Laid-Open No. 58-194913 discloses a polyoxy polyurethane having an average molecular weight of about 1500 to 6000. Alkylene glycol (polyoxyethylene glycol, polyoxypropylene glycol, etc.) and a small amount, a blend of a polyol having an average molecular weight of 500 or less and an aromatic diisocyanate are reacted and crosslinked,
At this time, either OH group or NCO group, preferably NCO / OH is 1 in relation to the elastic polyurethane foam.
In addition, JP-A-60-67524 discloses that a bifunctional or trifunctional polyether polyol or polyester polyol having an average molecular weight of 400 to 6000 is added to an ethylenically unsaturated compound. Are formed by polymerizing a polyol and a polyisocyanate, which are partially graft-polymerized, via an organometallic catalyst. In the composite laminate, as shown in FIG. 4, generally, first, the upper layer 1 is placed on a mold 5, and a liquid viscoelastic polyurethane is injected into the mold 5 to form a lower layer 7. In a state where both members are heated to about 60 to 80 ° C. by the upper and lower heater members 9 and 11, they are pressed against each other for a predetermined time as shown by arrows, and are pressed. The heel pad thus manufactured is characterized in that it has a low average density, is lightweight, has a large energy absorption effect, and does not cause discomfort even when used for a long time.

However, since the composite laminate 13 thus formed is of an integral type, when it is incorporated into athletic shoes or the like, the viscoelastic polyurethane constituting the lower layer 7 is concealed by the upper layer. Cannot be guaranteed or confirmed visually. In order to solve this problem, an upper layer made of an elastic polyurethane foam having a plurality of holes 17 as shown in FIG.
It has been proposed to make a composite laminate 19 in which the lower viscoelastic polyurethane can be seen from the portion 7.

[0004] The composite laminate 19 of such a form is formed in the same procedure as shown in FIG. 4, that is, after the lower layer 7 is formed by injecting a viscoelastic polyurethane in a liquid state into the mold 5, The piercing mold upper layer 15 can be produced by placing the upper layer 15 and then pressing both members. At the time of the pressing, the viscoelastic polyurethane overflows through the plurality of holes 17 onto the upper surface of the piercing mold upper layer 15. It turns out that a new problem arises. This problem can be solved by waiting for the viscoelastic polyurethane to harden to some extent before performing the pressing operation, but this not only weakens the mutual adhesion of the two members, but also increases the perforated upper layer. 1
As a result, the viscoelastic polyurethane is allowed to freely enter each of the holes 17, resulting in uneven heights inside the holes 17, which significantly reduces the commercial value. The above problem can also be solved by attaching the film member 21 to the perforated upper layer 15 as shown in FIG. 7, but such a film member significantly impairs the appearance of the composite laminate 19 as a product.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object to be solved is to solve the above-mentioned problems in the conventional method for producing a cushion sheet or the like and to produce a cushion sheet without impairing the appearance of the product. And to visually assure or confirm the presence of the underlying viscoelastic polyurethane by incorporating the cushion sheet into articles such as shoes.

[0006]

According to the present invention, there is provided a step of preparing a plate-shaped elastic polymer foam in which a plurality of holes having a predetermined size and shape are formed at predetermined intervals.
Injecting a viscoelastic polyurethane into a mold in a liquid state, placing the elastic polymer foam on the mold through a thermoplastic urethane film, and injecting the viscoelastic polyurethane. Pressing the mold and the elastic polymer foam together under heating at 60 to 80 ° C. to provide a cushion sheet.

[0007] The method of the present invention may include the step of adhering a thermoplastic urethane film to one side of the elastic polymer foam, and comprising a composite comprising the elastic polymer foam and the viscoelastic polyurethane pressed together. The method may also include a step of incorporating the laminate into a shoe product or the like with the elastic polymer foam side facing out, and a step of preparing an elastic polymer foam having a color tone distinct from the viscoelastic polyurethane. is there.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, the method of the present invention will be described in detail. FIG. 1 shows a plate-like upper layer 100 made of an elastic polymer foam, preferably an elastic polyurethane foam, used in the present invention. And has a perforated structure in which a large number of holes 17 are formed as in the conventional embodiment as shown in FIG. A thermoplastic urethane film member 120 is bonded to the upper layer 100 on the entire side surface opposite to the lower layer (not shown) made of viscoelastic polyurethane.

Liquid viscoelastic polyurethane is injected into the mold 5 to form the lower layer 7. After the lower layer 7 is cast, the upper layer 100 made of the elastic polyurethane foam described above is placed on the lower layer 7. Next, the upper layer 100 and the lower layer 7 are mutually pressed while being heated to 60 to 80 ° C. by the same heater means as shown in FIG. At this time, the viscoelastic polyurethane constituting the lower layer 7 pushes up the thermoplastic urethane film member 120 of the upper layer 100 at the hole 17 by a pressing force and tries to enter the same. Since the plastic urethane film member 120 elastically absorbs the pressing force and gradually expands into the inside of the hole 17, after all, while pushing up the thermoplastic urethane film member 120 of the viscoelastic polyurethane, The pressure for entering each hole 17 is equalized, and as a result, the height h of the viscoelastic polyurethane inside each hole 17 is constant.

[0010]

The thermoplastic urethane film member strongly adheres the upper layer made of elastic polyurethane foam and the lower layer made of viscoelastic polyurethane to each other, while the viscoelastic polyurethane inside the hole of the upper layer. Since the height h is made constant, a method for producing a cushion sheet which does not cause the problems of the conventional method as described above is provided. In addition, by incorporating this cushion sheet into an article such as shoes, the presence of the lower layer viscoelastic polyurethane can be visually assured or confirmed through the hole in the upper layer, and the color tone of the upper layer and the lower layer can be clearly identified. The distinction can provide an effect that the effect can be further emphasized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a state in which a thermoplastic urethane film member is attached to an upper layer of a perforated mold made of elastic polyurethane, which is used in a method of manufacturing a cushion sheet according to the present invention.

FIG. 2 is an enlarged partial cross-sectional view illustrating a situation in which a perforated upper layer illustrated in FIG. 1 and a lower layer made of viscoelastic polyurethane are pressed against each other.

FIG. 3 is an exploded perspective view of a cushion sheet including an upper layer made of elastic polyurethane and having no holes and a lower layer made of viscoelastic polyurethane.

4 is an exploded cross-sectional side view showing a relative positional relationship between an upper layer, a lower layer, a mold, and a heater member in producing the cushion sheet of FIG.

FIG. 5 is an exploded perspective view of a cushion sheet including a perforated upper layer made of elastic polyurethane and a lower layer made of viscoelastic polyurethane.

FIG. 6 is a cross-sectional view illustrating a situation in which viscoelastic polyurethane overflows from each hole of the upper layer when pressing the upper and lower layers when producing the cushion sheet illustrated in FIG.

FIG. 7 is a cross-sectional view illustrating a state in which a film member is adhered to the upper surface of an upper layer of a punch type.

[Explanation of symbols]

 5: Mold 7: Lower layer 17: Hole 100: Upper layer 120: Thermoplastic urethane film member

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A43B 1/00-23/30

Claims (4)

(57) [Claims] 1. A step of preparing a plate-shaped elastic type polymer foam formed by piercing a plurality of holes having a predetermined size and shape at predetermined intervals, and converting a viscoelastic polyurethane into a liquid in a mold. And placing the elastic polymer foam on the mold with a thermoplastic urethane film interposed therebetween. The mold and the elastic polymer foam in which the viscoelastic polyurethane is injected are provided. Pressing each other under heating at 60 to 80 ° C. 2. The method according to claim 1, further comprising the step of bonding a thermoplastic urethane film to one side of the elastic polymer foam. 3. The method according to claim 1, further comprising the step of incorporating a composite laminate of the elastic polymer foam and the viscoelastic polyurethane, which are pressed together, into a shoe product or the like with the elastic polymer foam side facing out. The method for manufacturing a shock-absorbing member according to the above. 4. The method according to claim 1, further comprising the step of preparing an elastic polymer foam having a color tone distinctly different from that of the viscoelastic polyurethane.