JP2981620B2 - Manufacturing method of upholstered vibration absorbing sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Purpose of the Invention><Industrial application field> The present invention relates to a sheet-like cushioning material made of silicone gel, for example, provided inside a shoe to reduce external impact.

<Background of the Invention> In recent years, attention has been paid to the vibration-absorbing properties of silicone gels, which are being used, for example, as shoes, supporters, cushioning materials for various protective equipment, and the like. However, if the silicone gel is bare, the surface feel is poor and the strength is low. Therefore, in order to use the silicone gel as a buffer or the like, some surface treatment was required.

<Technical matters attempted to be developed> The present invention has been made in view of such a background, and has been attempted to develop a cloth-covered vibration-absorbing sheet which aims to improve the feel of the surface of the silicone gel and reinforce the same. An attempt was made to develop a method for producing a cloth-absorbing vibration-absorbing sheet in which the elastic gel does not stick to the surface of the elastic cloth when the elastic cloth is provided on the silicone gel.

<< Constitution of the Invention >><Means for Achieving the Object> That is, the method for producing a cloth-absorbing vibration-absorbing sheet according to the first invention of the present application comprises a coating agent application step of applying a water-soluble coating agent to one surface of an elastic cloth, A gel forming step of pouring an undiluted solution of silicone gel so as to be in contact with the other surface of the nonwoven fabric, and then heating and curing the coating solution, and a coating agent eluting step of eluting the water-soluble coating agent into water. Things.

Further, in the method for producing a cloth-absorbing vibration-absorbing sheet according to the second invention according to the present application, in addition to the above requirements, in the gel molding step, granules are mixed in advance in the silicone gel stock solution and cured after the gel molding step. The method is characterized in that a step of forming pores by removing particles in the gel thus formed is provided, or the step of making porous is carried out simultaneously in the step of eluting the coating agent.

The present invention aims to achieve the above object.

<Function of the Invention> In the present invention, since a coating agent application step of applying a water-soluble coating agent to one surface of the elastic cloth is provided, the undiluted solution of the silicone gel oozes on the front surface of the elastic cloth and sticks. There is no.

<Example> Hereinafter, the present invention will be specifically described based on an illustrated example. FIG. 1 shows a state in which the upholstered vibration absorbing sheet 1 is applied to a heel K of an athletic shoe S. This upholstered vibration absorbing sheet 1
As shown in FIGS. 1 and 2, the elastic sheet 4 is provided on both sides of a gel sheet 2 having holes 3 formed continuously therein. Here, the silicone gel constituting the gel sheet 3 will be described. This is composed of dimethylsiloxane component units, and is a diorganopolysiloxane (hereinafter referred to as A) which is a stock solution of a silicone gel used in the following formula [1].
Referred to as _{^{component): RR 1 2 SiO- (R}} 2 2 SiO) n SiR 1 2 R ... [1] [ wherein, R is an alkenyl group, R ¹ is a monovalent no aliphatic unsaturated bonds hydrocarbon R ² is a monovalent aliphatic hydrocarbon group (at least 50 mol% of R ² is a methyl group, and when it has an alkenyl group, its content is
And n is a number such that the viscosity of this component at 25 ° C. is 100 to 100,000 cSt.]
And an organohydrogenpolysiloxane (component B), which is a stock solution of a silicone gel having a viscosity of not more than 5000 cSt at 25 ° C. and having hydrogen atoms directly bonded to at least three Si atoms in one molecule, and The mixture is adjusted so that the ratio (molar ratio) of the total amount of alkenyl groups contained in component A to the total amount of hydrogen atoms directly bonded to Si atoms in component B is 0.1 to 2.0. This is an addition reaction type silicone copolymer obtained by the above method. The component A has a linear molecular structure. The alkenyl group R at both ends of the molecule is added to a hydrogen atom directly bonded to a Si atom in the component B to form a crosslink. A compound capable of forming a structure. The alkenyl group present at the molecular terminal is preferably a lower alkenyl group, and a vinyl group is particularly preferable in consideration of reactivity. R ¹ present at the molecular terminal is a monovalent hydrocarbon group having no aliphatic unsaturated bond, and specific examples of such a group include alkyl groups such as a methyl group, a propyl group, and a hexyl group. , A phenyl group and a fluoroalkyl group. In the above formula [1], R ² is a monovalent aliphatic hydrocarbon, and specific examples of such a group include alkyl groups such as methyl group, propyl group and hexyl group, and vinyl groups. Lower alkenyl groups. However, at least 50 mol% of R ² is a methyl group, when R ² is an alkenyl group is preferably an alkenyl group is the amount of 10 mol% or less. When the amount of the alkenyl group exceeds 10 mol%, the crosslink density becomes too high and the viscosity tends to be high. N is 25 ° C. of the component A
Viscosity is usually 100 to 100,000 cSt, preferably 200
It is set to be within the range of ~ 200,000 cSt. The component B is a crosslinking agent for the component A, and the hydrogen atom directly bonded to the Si atom is added to the alkenyl group in the component A to cure the component A. The B component may have any of the above-mentioned effects, and may have various molecular structures such as a linear, branched chain, cyclic, or network structure. In addition, a hydrogen atom and an organic group are bonded to the Si atom in the B component, and this organic group is usually a lower alkyl group such as a methyl group. Further, the viscosity of the component B at 25 ° C. is usually 5,000 cSt or less, preferably 500 cSt or less. Examples of such a B component include an organohydrogensiloxane in which both molecular terminals are blocked with a triorganosiloxane group, a copolymer of a diorganosiloxane and an organohydrogensiloxane, tetraorganotetrahydrogencyclotetrasiloxane, HR ¹ ₂ SiO
Copolymer siloxane consisting of 1/2 unit and SiO 4/2 unit,
And HR ¹ ₂ SiO 1/2 units and R ¹ ₃ can be exemplified a copolymer siloxane consisting of SiO 1/2 units and SiO 4/2 units. However, in the above formula, R ¹ has the same meaning as described above. The ratio of the molar amount of the alkenyl group in the component A to the total molar amount of the hydrogen atoms directly bonded to Si in the component B is usually 0.1 to 2.0, preferably 0.1 to 1.0. It is manufactured by mixing and hardening the A component and the B component so as to be as follows. The curing reaction in this case is usually performed using a catalyst. As the catalyst used herein, a platinum-based catalyst is preferable, and examples thereof include finely pulverized elemental platinum, chloroplatinic acid, platinum oxide, a complex salt of platinum and olefin, platinum alcoholate, and chloroplatinic acid and vinylsiloxane acid. Can be mentioned. Such a complex salt is A
It is usually used in an amount of 0.1 ppm or more, preferably 0.5 ppm or more, based on the total weight of the component and the component B. The upper limit of the amount of such a catalyst is not particularly limited. For example, when the catalyst is in a liquid state or can be used as a solution, an amount of 200 ppm or less is sufficient. Here, compounds such as sulfur, phosphorus, tin-based compounds, and amines easily react with the platinum-based catalyst, and are so-called catalyst poisons that inhibit crosslinking and curing. These include, specifically, sulfur compounds such as potassium sulfate, ammonium sulfate, ammonium persulfate, sodium persulfate, sodium sulfite,
Sulfates such as hydrosulfide and sulfur hydroxyamine, sulfur, carbon disulfide, thioglycolic acid such as sodium sulfoxylate (Rongalit), butyl thioglycolate and derivatives thereof, mercaptan compounds such as β-mercaptopropionic acid, thioacetic acid Surfactants such as thiourea, sulfonate and sulfate. Examples of the phosphorus-based compound include phosphoric acid, ammonium phosphoric acid phosphorous acid, sodium hypophosphite pyrophosphate, sodium metaphosphate, sodium tripolyphosphate and the like, and salts thereof, trimethyl phosphate, dialkyldithiophosphoric acid, phosphite and the like. Can be Examples of the tin compound include various tin chlorides and tin oxides, and other examples include rhodan salts and stannous sulfate. Examples of the amine compound include iminobispropylamine, triethylamine, 3-dieaminopropylamine, and tetramethylethylenediamine. , 3-methoxypropylamine and the like. Then, the above-mentioned component A, component B and the catalyst are mixed and left to stand at room temperature or heated to be cured to form the silicone gel used in the present invention. When curing by heating, the heating temperature is usually 50 to 160 ° C. The silicone gel thus obtained is JIS K (K-2207-198)
The penetration, measured at 0 g), is usually between 5 and 250.
With the hardness of such a silicone gel, the amount of the component A can form a crosslinked structure with hydrogen atoms directly bonded to Si in the component B. As another method, it can be adjusted by previously adding a silicone oil having methyl groups at both ends in an amount within a range of 5 to 75% by weight based on the obtained silicone gel. The silicone gel can be adjusted as described above, or a commercially available silicone gel can be used. Examples of commercially available products that can be used in the present invention include CF5027, TO
UGH-3, TOUGH-4, TOUGH-5, TOUGH-6 (Toray
Dow Corning Silicone) or X32-902 / cat1300
(Manufactured by Shin-Etsu Chemical Co., Ltd.) and F250-121 (manufactured by Nippon Yunika Co., Ltd.). In addition, in addition to the above-mentioned components A, B and the catalyst, pigments, curing retarders, flame retardants, fillers and the like can be blended within a range that does not impair the properties of the silicone gel. May be used. Silicone gel obtained by mixing Nippon Philite Co., Ltd., or Expancel (registered trademark) sold by Nippon Philite Co., Ltd., Matsumoto Microsphere (Matsumoto Yushi Pharmaceutical Co., Ltd.) Company production and sales). Next, as the stretchable cloth 4, besides a cloth that can be stretched vertically and horizontally, such as a cloth constituting a stocking or a knit-like cloth, a cloth that can expand and contract only in one direction, such as vertical or horizontal, can be used. For convenience of description, the surface of the elastic cloth 4 on the side that adheres to the silicone gel is defined as the back surface, and the opposite surface is defined as the front surface. Further, in the present embodiment, the elastic cloth 4 is provided on one side of the gel sheet 2, but the elastic cloth 4 may be provided on both sides of the gel sheet 2 depending on the application location of the upholstered vibration absorbing sheet 1 and the purpose of use.
May be provided.

Next, a method for manufacturing such a fabric-clad vibration-absorbing sheet 1 will be described. This manufacturing method includes a coating agent application step, a gel molding step, and a coating agent elution step. When the gel sheet 2 is made porous, a porous step is provided after the coating agent elution step, between the gel forming step and the coating agent elution step, or simultaneously with the coating agent elution step. Hereinafter, each step will be described.

Coating Agent Application Step This step is a step of applying a water-soluble coating agent to the front surface of the elastic cloth 4 and is a characteristic step of the present invention. The significance of this step is as follows. That is, when the stock solution of the silicone gel is poured into the back side of the stretchable cloth 4 in the gel forming step described later, if the stock solution remains as it is, the stock solution that has flowed into the front side of the stretchable cloth 4, When this is cured, the front surface of the elastic cloth 4 becomes sticky. Therefore, a water-soluble coating agent is applied so that the undiluted solution of the silicone gel does not seep out to the front side of the elastic cloth 4. As the water-soluble coating agent, polyvinyl alcohol or the like can be applied. In addition, when polyvinyl alcohol oozes on the back surface of the elastic cloth 4, the adhesiveness between the silicone gel and the elastic cloth 4 is reduced.
The application amount of polyvinyl alcohol is set to an extent that does not leach onto the back surface of the elastic cloth 4. In this connection, if a hydrogen siloxane corresponding to the B component of the silicone gel stock solution is applied in advance, the cross-linking of the applied surface is promoted and the tackiness is reduced. In addition, this also strengthens the adhesion. Further, if a primer is applied, the adhesion to the cloth can be strengthened.

Gel Forming Step A stock solution of silicone gel is poured into the back side of the elastic cloth 4 and then heated to cure the silicone gel. As a result, the silicone gel is adhered to the elastic cloth 4.

Coating agent elution step This is a step of immersing a sheet-like product formed in the gel molding step in hot and cold water to elute the coating agent into water. Thereby, a sheet in which the elastic cloth 4 is provided on the surface of the silicone gel is obtained.

Porosity Step This is a step provided when the gel sheet 2 is made porous.
As a method for making the gel sheet 2 porous, a silicone gel stock solution is mixed with a heat-dissipating substance, which is a granule, and cured by heating, and then the heat-dissipating substance is heat-dissipated to form pores in that portion. The heat-dissipation method, drying and shrinking the swollen granules mixed in the silicone gel stock solution, and removing this from the traces of the swollen granules, the volatile volatile liquid having a large dielectric loss coefficient in the silicone gel stock solution The liquid is heated in a high-frequency electric field by dielectric heating, and the liquid is heated, vaporized and expanded, and at the same time, a microwave heating method for cross-linking and curing of the silicone gel stock solution is used. After mixing and curing in the silicone gel stock solution, an elution method or the like in which particles are eluted in a solvent such as water to form pores can be applied. When the elution method is applied, when the solvent is water, sodium polyacrylate, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, polyethylene oxide, polyvinyl pyrrolidone,
Acrylic amide, glue, gelatin, casein, polypeptide, funori, agar, sodium alginate, sodium chloride, glucose, sucrose, natural polysaccharide pullulan, xanthan gum, starch, sodium ascorbate, and acetone, ethanol When methanol or the like is used as the solvent, polyvinyl alcohol, methyl cellulose, ethyl cellulose, water-soluble nylon, shellac, styrene, or the like can be selected as the particles.
Also, when adopting any of these porous methods,
As a prerequisite, in the gel forming step, granules corresponding to the respective porous methods are mixed in advance in the silicone gel stock solution.

Hereinafter, as one example, a method for producing the cloth-absorbing vibration absorbing sheet 1 according to the present invention in which the gel sheet 2 is made porous by applying the elution method will be specifically described with reference to FIG. First, a knitted cloth is used as the elastic cloth 4, and polyvinyl alcohol is applied to the cloth by a roll coater R and dried as shown in FIG. 2 (b). In addition, in the coating agent application process for a thin and easily permeable fabric such as a stocking material, it is desirable to apply a very thin coating on the surface, for example, as in silk printing. Next, this is laid inside the recess A of the bat B with the surface on the side coated with polyvinyl alcohol facing down, as shown in FIG. When a thin sheet is manufactured, the sheet may be flowed on a flat plate such as a glass plate. On the other hand, sodium chloride is distributed and mixed into the component A and the component B so that the weight ratio of the sodium chloride to the stock solution of the silicone gel is 2: 1, and the component A, the component B, and the catalyst are further mixed. As the sodium chloride, a commercially available crystal having a substantially uniform cubic shape of about 0.4 mm was used. Then, a mixture of the sodium chloride and the stock solution of the silicone gel is poured into the recess A of the vat B, which is heated and cured. In addition, in order to remove air taken in at the time of mixing, it is desirable to perform vacuum defoaming before curing. If the amount of the stock solution of the silicone gel is somewhat larger than that of the sodium chloride, the sodium chloride is naturally cured during the curing, and is sequentially deposited from the bottom of the stock solution of the silicone gel. The gel hardens in a state where it is filled with the stock solution of the gel. Alternatively, when pressed from above and below during this time, an excessive amount of the silicone gel stock solution with respect to the sodium chloride is squeezed out, overflows from there, and hardens in a state where an appropriate amount of the silicone gel stock solution exists between the sodium chlorides. Therefore, if left at 80 ° C for 1 hour, for example,
The components react with each other to obtain a cured product in which sodium chloride is substantially densely deposited inside the vat B. When the amount of the stock solution of the silicone gel is larger, a layer composed of only the silicone gel is formed on a part of the surface layer. When the elastic cloth 4 is provided on the side of the layer made of only the silicone gel, the adhesion between the elastic cloth 4 and the silicone gel is enhanced, but the air permeability is reduced by that amount. Also, as in the example, the specific gravity ratio between sodium chloride and the stock solution of silicone gel is
If the ratio is about 2: 1, a layer consisting only of the silicone gel is not formed on the surface layer, and the entire layer is a layer of the silicone gel in which sodium chloride is dispersed. Contrary to this, when the amount of sodium chloride increases, it becomes difficult to mix the silicone gel with the stock solution and vacuum degassing operation, while the occupation of sodium chloride occupying pores increases, so that the net structure becomes thin in the finished state. Things are obtained. In practice, the weight ratio of the weight of sodium chloride to the stock solution of silicone gel is preferably 1.5: 1 to 4: 1, preferably about 2: 1. Next, the cured silicone gel in a state where sodium chloride is dispersed is taken out of the mold, and as shown in FIG. 2 (f), the silicone gel is put into a bath in which warm water is stirred. And after changing the boiling water while changing the hot water several times, cut the hot water and dry it.
As shown in the figures (g, h), pores as traces of removal are formed in the portions of the silicone gel where sodium chloride was present, and a sheet that has been made porous in the form of open cells is obtained.
In general, a skin layer tends to be formed on a portion which is hardened by contact with a molding die, and thereby dissolution of sodium chloride is inhibited. Therefore, the skin layer is peeled off, and the surface layer is pierced or crushed. When the sodium chloride is eluted in the above step, the internal sodium chloride is exposed and the elution can be performed accordingly. In such a porous process, the water-soluble coating agent, polyvinyl alcohol, also dissolves in hot water at the same time, so that the coating agent elution process substantially proceeded at the same time, whereby the upholstered vibration absorbing sheet 1 is obtained. . It should be noted that the porosity step and the coating agent elution step can be allowed to proceed at the same time only when water is used as a solvent in the elution method. When using other porous methods such as the drying method, drying shrinkage method or microwave heating method, a coating agent that elutes the coating agent by immersing the porous sheet in water before or after the porous process It is necessary to provide an elution step.

<< Effect of the Invention >> In the manufacturing method of the cloth-absorbing vibration-absorbing sheet 1 according to the present invention, a coating agent application step of applying a water-soluble coating agent to one surface of the elastic cloth is provided. The upholstered vibration-absorbing sheet 1 having no stickiness on the surface is obtained without leaching to the front surface.

When the gel sheet 2 is made porous by applying an elution method using water as a porous method, a pore forming step of forming pores by removing particles in the gel and eluting a water-soluble coating agent. The coating agent elution step can proceed simultaneously.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment in which the upholstered vibration absorbing sheet is applied to athletic shoes, and FIG. 2 is an explanatory view showing step by step the method of manufacturing the upholstered vibration absorbing sheet of the present invention. 1; Upholstered vibration-absorbing sheet 2; Gel sheet 3; Void 4; Elastic cloth A; Recess B; Bat K; Heel R; Roll coater S; Sports shoes

Claims (2)

(57) [Claims] 1. A coating agent application step of applying a water-soluble coating agent to one side of a stretchable cloth, and a gel forming step of pouring an undiluted silicone gel solution into contact with the other side of the stretchable cloth, and then heating and curing the silicone gel. And a coating agent eluting step of eluting the water-soluble coating agent into water. 2. In the gel forming step, there is provided a porous forming step in which granules are mixed in advance with the silicone gel stock solution, and after the gel forming step, granules in the hardened gel are removed to form pores. The method according to claim 1, wherein the step of providing the porous material and the step of eluting the coating agent are simultaneously performed in the step of dissolving the coating agent.