JP2714734B2 - How to make insoles for shoes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a shoe insole.

[0002]

2. Description of the Related Art It is important to use sports shoes such as ski boots, skating boots, mountain climbing boots and the like that conform to the shape of the user's foot. Conventionally, polyethylene foams, EVA foams, felts, nonwoven fabrics and the like have been used for these insoles. However, the shape and irregularities of the insole inside the shoe are processed into a standard footprint, and it is difficult to manufacture the shoe according to the footprint of the user. As a manufacturing method similar to this, there is known a step of sewing a cloth that has been subjected to a filling process in a method of manufacturing an inner boot into a foot shape, and injecting a urethane foaming liquid having shape memory into the cloth. (JP-A-2-95388).

[0003]

In the above-mentioned conventional method of manufacturing an inner boot, the polyurethane foam layer is softened at a high temperature and deformed in a softened state, and the deformation is fixed to improve the shape memory property. It is provided. However, this polyurethane foam is characterized in that its glass transition point is lower than the human body temperature, so that it begins to soften at the temperature in the drying room of the ski dormitory (40 to 45 ° C.). It was necessary to repeat the work of deforming according to the feet of the user.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide the following method of manufacturing an insole. <B> Manufacturing method of shoe insole with a shape that matches the user's personal footprint <b> Once transformed into his / her footprint, it does not return to its original shape within the normal operating temperature range, A method of manufacturing insoles that keeps the foot mold.

[0005]

That is, the present invention uses a shape memory polyurethane foam cut into a flat shape on the back side of a human foot as a core material, and the shape memory polyurethane foam is
As a riol component, it has 3 to 5 functional groups and an average hydroxyl group
Polyether poly having a value of 370 to 670 mg KOH / g
All is 95-5 based on the total weight of the polyol component
0% by weight and 5-50% by weight of polymer polyol
Then, the core material is obtained by reacting it with a polyfunctional isocyanate.
℃ heated to soften and impart sectional equal shape of the footprint of the user in a softened state, to produce cured by lowering the temperature to a temperature of use while imparting shape of shoe insoles
It is a manufacturing method. Further, the present invention is a method for producing a shoe insole, wherein the front and back surfaces of the core material of the shape memory polyurethane foam are surrounded by a protective sheet, and the outer periphery thereof is further covered with a film.

[0006]

DETAILED DESCRIPTION OF THE INVENTION In the manufacturing method of the present invention, first, a sheet of a shape memory polyurethane foam is cut in a shape close to a plane shape of a sole of a human foot. Since there are few personal differences in the planar shape, although there are differences in the size, it is sufficient to prepare several types of approximately average shapes having different dimensions. On both sides of the insole, another thin member is attached as a protective sheet to reinforce and adjust friction.

Next, the insole is set inside ski shoes, skating shoes, or the like. And 50 ° C to 120 ° C, preferably 10 ° C from the glass transition point of the polyurethane foam.
The high-temperature hot air is sent into the shoe to soften the polyurethane foam. Once softened sufficiently, the user's foot is inserted into the shoe in that condition and the buckle or string is tightened in the same manner as in use. Since the softened polyurethane foam is deformed, it is left as it is or is blown with cold air to be hardened. In this way, an insole is manufactured that fits exactly into the cross section of the user's individual foot.

An embodiment of the present invention will be described below with reference to the drawings. <A> Insole of polyurethane foam The insole manufactured in the present invention is constituted by a shape memory polyurethane foam. For that purpose, the thickness should be 5-1
A sheet 1 of a plate-shaped shape memory polyurethane foam of about 5 mm is prepared. From the sheet 1, the core material 2 is cut out in a shape close to the planar shape of the sole of the human foot. (FIG. 1) At this time, the thickness of the core material 2 may not be constant, and the toe end direction of the foot may be formed thin. This shape memory polyurethane foam has a glass transition point of 50 ° C to 100 ° C, preferably 60 ° C.
~ 80 ° C is adopted. In order to achieve such an object, the following can be used as the shape memory polyurethane foam.

In the present invention, the glass transition point is from 50 ° C. to 100 ° C.
It must be in ° C. The glass transition point or molding temperature of the polyurethane foam depends on the average hydroxyl value of the raw material polyether polyol. Thus, the lower the average hydroxyl value of the polyether polyol is, the lower the glass transition point of the foam is generally, and the higher the average is, the higher the glass transition point is. Thus, the molding temperature of the foam can be freely changed depending on the average hydroxyl value of the polyether polyol. In the present invention, a polyether polyol having 3 to 5 functional groups and an average hydroxyl value of 370 to 670 mgKOH / g is used.

Specific examples of polyether polyols useful in the present invention include the following: "Boranol" 2025, 2070, 360, 370;
446, 490 (manufactured by DOWCHEMICAL); "ADEKA polyether" P-400, G-300, G-
400, G-700, SP-600, SP-690 (manufactured by Asahi Denka) "ACT CALL" 51-530, 52-460, 21-
56 (manufactured by Takeda Pharmaceutical Co., Ltd.) “San Nix” GP-600, GP-400, PP-
750, HS-209, HR-450P, HA-501
(Manufactured by Sanyo Chemical); The present invention is characterized in that the above-mentioned polyether polyol is used in combination with a general polymer polyol obtained by polymerization of a monomer having a polymerizable unsaturated group, as a polyol component.

The polymer polyol in the present invention is obtained by polymerizing a monomer having a polymerizable unsaturated group in a polyether polyol. The polymer polyol acts as a stabilizer and does not substantially affect the glass transition point of the resulting foam. When used together, the amount of the polymer polyol used is 5 to 50% by weight, preferably 15 to 35% by weight, based on the total weight of the polyol component.
Is suitably within the range. Specific examples of polymer polyols that can be used include the following: "Boranol" 3940, 3943 (DOW CHEMICAL
): "PLURACOL Polyol" 994L
V, 1003, 1055 (manufactured by BASF);

On the other hand, as the polyfunctional isocyanate to be reacted with the polyol component described above, any isocyanate conventionally used in the production of polyurethane can be used, for example, toluene diisocyanate (TDI), Examples include diphenylmethane diisocyanate (MDI), polymeric MDI, naphthylene diisocyanate (NDI), and tolidine diisocyanate (TODI). When the specific polyether polyol and the polymer polyol are used in combination as the polyol component, a polyurethane foam having fine and uniform cells can be easily obtained. The amount of the polymer polyol to be added can be changed depending on the hydroxyl value of the polyether polyol used in combination. Generally, when the amount is too small, coarse bubbles and collapse tend to be generated. When the amount is too large, it tends to be difficult to obtain a good foam.
If the amount of the polymer polyol is increased within the above range, the foam can be made flexible at room temperature while maintaining the desired thermoformability.

As the foaming agent, various foaming agents known in the field of polyurethane foam can be used. As in the prior art, water can be suitably used, and as a foaming aid, for example, chlorofluorocarbon (Freon- 1
1, -12, -113, -123, -141b, -14
3b), methylene chloride, acetone and the like. As the foam stabilizer, a conventionally known foam stabilizer can be used, and it can be appropriately selected from commercially available urethane stabilizers. As the catalyst, those known per se for urethane can be used if necessary. Further, a flame retardant or the like can be added and blended as needed.

The shape memory polyurethane foam of the present invention can be produced by reacting the above-mentioned components by a method known per se. For example, it can be produced by mixing each component other than the polyfunctional isocyanate, adding the polyfunctional isocyanate to the mixture, sufficiently stirring and mixing, and then pouring the mixture into a mold. Examples of foaming are shown in Examples 1 to 4 in Table 1.

[0015]

Next, the present invention will be described more specifically with reference to examples. Examples 1-4 The following were used as a polyol component . Polyol A: propylene oxide ethers of functionality 3, which is derived from glycerin having a hydroxyl value of 374, polyol B: propylene oxide ethers of functionality 3, which is derived from glycerin having a hydroxyl value of 406, polyol C: derived glycerin having a hydroxyl value of 660 Propylene oxide having 3 functional groups .

One or more of the above-mentioned polyol components A to C is blended with a blowing agent, a foam stabilizer, a catalyst and an organic isocyanate shown in FIG. 5 and a blending composition shown in FIG. ) To carry out a polymerization reaction. FIG. 5 also shows the glass transition point (preferably molded at a temperature higher by 10 ° C. or higher), which is a measure of the molding temperature of the obtained foam, and the state of the cells. The above polymerization reaction was carried out under the following conditions: The temperature of the reagent to be used was previously adjusted to 20 to 25 ° C (however, Freon 11 was 15 ° C). After the components other than the isocyanate are blended in accordance with the composition and sufficiently stirred, the isocyanate component is added to the mixture, and the mixture is rapidly stirred with a 3000 rpm mixer for 5 seconds and poured into a mold (box) covered with release paper. When the foaming was completed and cured, it was removed from the mold, cured for one day, and then cut to obtain a sample for measuring physical properties.

<B> Attachment of protective sheet A thin sheet for protecting the polyurethane foam is attached to the front and back surfaces of the core material 2 described above. As the surface material 3 to be attached to the surface, a thin sheet of polyester cloth, cotton pile, artificial leather, real leather, or the like can be used.
Since these surface materials 3 are on the side directly in contact with the socks, it is desirable that the materials have a small coefficient of friction. A thin sheet such as a polyurethane sheet or a vinyl chloride sheet is attached to the back of the insole as the back material 4. The thickness is, for example, about 50 to 100 μm. Since these backing members 4 are on the side directly in contact with the sole of the shoe, it is desirable that the backing members 4 be made of a material having a large coefficient of friction and sufficient elasticity. Any adhesive such as chloroprene rubber, nitrile rubber, SBR, and butyl rubber can be used for attaching the front surface material 3 and the back surface material 4, but in particular, heat resistance, weather resistance, and adhesive strength. It is desirable to use an excellent chloroprene rubber-based adhesive.

<C> Coating with film etc. The periphery of the core material 2 in which the front surface material 3 and the back surface material 4 are thus overlapped is
Furthermore, it may be surrounded by cloth or film and adhered. At this time, a film having a slight elasticity such as a styrene-based film or a polyurethane film is used. The core material 2 in which the front surface material 3 and the back surface material 4 are overlapped can be used as the insole 5 as it is.

<D> Heating The insole 5 configured as described above is laid on the bottom of the shoe 6 to be used. (FIG. 2) Then, heated air having a temperature of 50 ° C. to 120 ° C., preferably 10 ° C. or higher than the glass transition point is blown. Such a temperature can be easily created by, for example, a dryer. For example, the molding temperature of Examples 1 and 2 is 70 ° C, the molding temperature of Example 3 is 95 ° C, and the molding temperature of Example 4 is 120 ° C. (FIG. 5) When the polyurethane foam is sufficiently softened by heating, the user himself puts his / her foot inside the shoe 6 and tightens the buckle 7 and the string to deform it to a state that matches the cross-sectional shape of the foot. The softened shape memory polyurethane foam has a stress (0.1 to 2.0 kgf / c) that can be applied by the buckle 7 or the like.
m ² ) can provide sufficient deformation. When the temperature is lowered to 40 ° C. or less, the feet are removed from the shoes 6, and the insole 5 as shown in FIG. 3 is completed. The glass transition point of the polyurethane foam used here is 50.
Since the temperature is about 100 ° C. to 100 ° C., the deformation of the insole 5 is fixed, and does not return to the original shape under normal use conditions.

Since the present invention has been described above, the following effects can be obtained. <a> This is a method in which a person used for a softened shape memory polyurethane foam presses a foot to give a shape. Therefore, it is possible to manufacture the insole 5 of the shoe 6 having a shape that exactly matches the footprint of the user. <B> Once transformed into their own footprints, they will not return to their original shape within the normal operating temperature range of a dry room in a ski dormitory, and will keep their foot shapes. <C> Since the shape memory polyurethane foam is used, it can be adjusted repeatedly by reheating the insole once molded to fit the footprint. <D> If a protective sheet having an appropriate coefficient of friction is attached to the front and back sides of the polyurethane foam, it is comfortable to use without slippage. Further, since the entire surface is surrounded by the film, the durability of the polyurethane foam is improved, and a decrease in strength can be prevented even under wet heat conditions. <E> Since the glass transition point is 50 ° C. to 100 ° C., when fitted to a footprint, a low modulus of elasticity is exhibited by increasing the temperature, and when used at a low temperature such as on snow, a high modulus of elasticity is exhibited. Thus, a good feeling in use can be obtained in actual use.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a state in which a shape memory polyurethane foam is cut out from a sheet.

FIG. 2 is an explanatory view of a state of being stored in shoes.

FIG. 3 is a sectional view of an insole

FIG. 4 is a plan view of an insole whose periphery is covered with a film.

FIG. 5 is a diagram showing a comparison of glass transition points according to differences in polyols.

Continued on the front page (72) Inventor Kenji Kawamoto 2923 Nisshinbo Spinning Co., Ltd. Nagoya Plant, Toyotamachi, Minami-ku, Nagoya City, Aichi Prefecture Inside the Nagoya Plant (72) Inventor Toshiharu Fukushima 10-1 Nakazawacho, Hamamatsu-shi, Shizuoka Yamaha Inside the Company (72) Inventor Takashi Okada 10-1, Nakazawa-cho, Hamamatsu City, Shizuoka Prefecture Inside the Yamaha Corporation (72) Inventor Takashi Haga 10-1, Nakazawa-cho, Hamamatsu City, Shizuoka Prefecture Inside the Yamaha Corporation (56 References JP-A-3-4802 (JP, A)

Claims (2)

(57) [Claims] 1. A shape memory polyurethane foam cut into a flat shape on the sole side of a human foot is used as a core material, and the shape memory polyurethane foam is used as a polyol component.
The number of functional groups is 3 to 5 and the average hydroxyl value is 370 to 67
0 mg KOH / g polyether polyol
95 to 50% by weight based on the total weight of the
5 to 50% by weight of mer polyol
It is obtained by reacting with anate, and a protective sheet is attached to the front and back surfaces of the core material, and the core material is heated to 50 ° C to 120 ° C and softened. A method of manufacturing shoe insoles, in which the temperature is reduced to the temperature at the time of use and the product is cured while maintaining the shape . 2. The method for producing an insole according to claim 1, wherein a protective sheet is attached to the front and back surfaces of the core material of the shape memory polyurethane foam, and the outer periphery is further covered with a film .