JP2002361749A - Air-permeable waterproof rubber molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded product which sufficiently exhibits air- permeability and waterproofness regardless of the shape and thickness of the molded product and also high practical strength, can be certainly and efficiently manufactured with the described characteristics, and further, is provided with an easy-to-wear shoe sole highly durable, air-permeable and waterproof. SOLUTION: This air-permeable waterproof rubber molded product is composed of a composition obtained by blending 100 pct.wt. of pulverized granule of vulcanized rubber having a grain size distribution of 0.5 to 1.8 mm, with 5 to 15 pct.wt. of liquid rubber. In addition, the product is a compression-molded product with communicating pores 3 consisting of gaps, between the granules 1, which are formed in a three-dimensional reticular fashion. Further, the molded product has a water-repellent skin 4 formed on the inside of the communicating pores 3 by impregnating the molded product with a water repellent for air- permeablity and waterproofness. The shoe sole is partially or totally formed of the rubber molded product, and thus is made air-permeable between the outside and the inside of the shoe through the rubber molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breathable waterproof rubber molded product, a shoe formed using the same, and a method of manufacturing the breathable waterproof rubber molded product.

[0002]

2. Description of the Related Art Generally, in sports clothing and the like,
Reduces humidity by dissipating water vapor such as sweat from inside the clothes,
In addition, there is known a garment fabric in which a breathable waterproofing process is performed to prevent rain and dew from penetrating from the outside of the garment, and for example, a porous synthetic resin film (porous film) is laminated on a base fabric and integrated. .

As an example of such a synthetic resin film,
A stretched polytetrafluoroethylene resin film has so-called microporous film having fine pores with a pore diameter of 1 μm or less, and this film has both air permeability and excellent waterproofness (water pressure resistance). It shows physical properties.

[0004] In addition, in a shoe that covers the upper of the foot, the inside of the shoe tends to be stuffy with sweat, and in order to prevent this, ventilation for introducing air from the outside of the shoe to the inside of the shoe at key points in the shoe sole. Japanese Unexamined Patent Publication No. Hei 6-1 provides a passage and a check valve for forced ventilation.
No. 09097.

[0005]

However, since the above-mentioned conventional breathable waterproof film made of a microporous film is a material having no strength that can be formed by itself, it is usually laminated with a cloth or other strength. It is used as a composite with a material having a certainty, and it is difficult to form a three-dimensional form by itself.

Further, since the breathable waterproof film is apt to be peeled or abraded and torn, it is difficult to use the film under sliding friction. Was not considered a practical embodiment.

[0007] A ventilation mechanism that requires a ventilation path and a check valve at key points in the shoe sole is not preferable because it complicates the structure of the shoe and thereby complicates the manufacturing process.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a sufficiently breathable and waterproof material when used in daily life, regardless of the shape and thickness of a three-dimensional or planar material. In other words, the purpose is to provide a breathable waterproof rubber molded article having the required strength and practical strength, or to efficiently produce a breathable waterproof rubber molded article having such characteristics reliably.

Another object of the present invention relating to the shoe of the present invention is to solve the above-mentioned problems, to provide a durable shoe sole with durable air permeability and waterproofness, and to have a simple structure. The aim is to provide shoes that are easy to manufacture.

[0010]

In order to solve the above-mentioned problems, in the invention relating to the breathable waterproof rubber molded article of the present invention, the liquid rubber 5 is used for 100 parts by weight of the pulverized particles of the vulcanized rubber.
１５15 parts by weight, and the composition was compression-molded so that continuous air holes formed by gaps between the crushed particles were formed in a three-dimensional network. It was impregnated with a liquid agent to provide a breathable waterproof rubber molded article having a water-repellent film provided inside the continuous ventilation holes.

As shown in FIG. 1, the air-permeable waterproof rubber molded article of the present invention configured as described above has a predetermined amount of pulverized rubber vulcanized rubber particles partially containing liquid rubber as a binder. It is a porous body bonded like a sintered body, and continuous air holes are formed in a three-dimensional mesh shape by continuously forming gaps (gap) where pulverized particles of the vulcanized rubber are partially separated from each other. Of the molded product communicates from one side to the other side.

When a molded article is impregnated with a water-repellent agent to provide a water-repellent film inside the continuous ventilation holes, usually,
As shown schematically in FIG. 2, the vent hole is a thin tube, where water should enter the thin tube by capillary action (FIG. 2).
b), the water is excluded from the capillary (FIG. 2a).

The mechanism will be described in detail. If the thin tube shown in FIG. 2 is a circular tube having a radius a and a contact angle of θ, when the liquid surface can be approximately approximated by a spherical surface having a radius of curvature a / cos θ, the surface tension If the magnitude of γ is γ, the pressure difference is 2γ cos θ / a. Therefore, the length h of the rise or fall of the liquid surface is represented by the following equation, where g is the gravitational acceleration, and ρ is the density of the liquid. Is done. h = 2γcosθ / ρga As is clear from this equation, when the contact angle between water and the inner wall of the pipe is an acute angle, h> 0 and the liquid level rises, and when the contact angle is an obtuse angle, that is, Since the contact angle becomes obtuse on the inner surface of the vent hole impregnated with the liquid agent, h <0, and the liquid surface falls, the waterproofness is exhibited according to the above formula.

In order to solve the above-mentioned problems, in the invention according to the shoe of the present application, a part or the whole of a shoe sole is formed by a breathable waterproof rubber molded article having the above-described structure, and the breathable waterproof rubber is formed. The outside and inside of the shoe could be ventilated through the molded body.

[0015] In the shoe of the present invention configured as described above, since the inside of the shoe communicates with the vent hole of the breathable waterproof rubber molded body from the sole, the required air permeability is ensured, and the inside of the shoe is secured. It will not be stuffy with sweat. In addition, since water droplets do not enter from the air holes impregnated with the water repellent, water does not infiltrate from the soles of the shoe, and the shoe has a waterproof sole that is necessary at the time of rain or the like.

Further, in order to solve the above-mentioned problems, the invention according to the method for producing a breathable waterproof rubber molded article of the present invention relates to a method for producing a vulcanized rubber pulverized particle having a particle size distribution of 0.5 to 1.8 mm.
A mixture of 0 parts by weight and 5 to 15 parts by weight of liquid rubber is filled in a mold, and the compression ratio is set to (1 / 2.35) to (1 / 2.18).
Then, the molded article is molded by pressurizing and heating, and then the molded article is impregnated with a water-repellent agent to form a water-permeable waterproof rubber molded article in which a water-repellent film is formed inside the continuous ventilation hole.

According to the manufacturing method comprising the above steps,
The pulverized vulcanized rubber particles having a predetermined particle size distribution and the liquid rubber are homogeneously mixed and filled into the cavity in the mold, so that the waterproofness and the air permeability are appropriately balanced. Further, in this way, it is possible to manufacture a compression-molded body having a three-dimensional network structure in which continuous air holes formed by gaps between the pulverized particles are reliably communicated from one surface to the other surface of the molded body.

When the molded article is impregnated with a water repellent, a water repellent film is formed from the whole inside or the surface of the continuous vent to the deep part of the pore, so that the waterproof property can be surely exhibited.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The pulverized particles of vulcanized rubber used in the present invention are not particularly limited to the type of rubber, but may be any vulcanized, ie, crosslinked, elastic rubber. As a preferable material because it is available as a low-cost reusable resource, a rubber forming a casing of a tire of an automobile or the like, that is, a rubber of a so-called used waste tire, and a specific rubber used for this is used. Typical rubber types include natural rubber, butyl rubber, nitrile rubber, isoprene rubber,
Butadiene rubber, styrene-butadiene rubber, and the like. When oil resistance is required, acrylonitrile-
It is preferable to use butadiene rubber (NBR), and ethylene-propylene-diene rubber (EPDM) when weather resistance is required.

The pulverized particles of the vulcanized rubber are particles obtained by mechanically pulverizing a molded and vulcanized rubber product, and have a particle size distribution of 0.5 to 1.8 mm. It has been found that when adopted, a material excellent in breathability and waterproofness can be reliably obtained.

The liquid rubber used in the present invention has a function of binding particles when the above-mentioned crosslinked rubber is employed, and has a terminal isocyanate group (-NCO).
Liquid polybutadiene having an isocyanate group (-NCO) at the terminal, and the like, are preferred because they can well bind the pulverized particles of vulcanized rubber derived from waste tires.

Such liquid rubber is blended in an amount of 5 to 15 parts by weight based on 100 parts by weight of the pulverized rubber vulcanized particles. This is because, if the amount is less than the predetermined range, the size of the communication hole becomes too large and the waterproof performance is inferior to the expected level. This is because the airflow resistance becomes too small and the airflow resistance becomes lower than expected.

A mixture of 100 parts by weight of the pulverized vulcanized rubber and 5 to 15 parts by weight of the liquid rubber is filled into a mold at a ratio of 91 to 98% of the cavity volume, and the volume is reduced to 1/2.
Compress to 4 and heat to form. That is, the above mixture is filled in a mold, and a compression ratio (1 / 2.35) to
Pressing and heating at (1 / 2.18) and molding.

If the compression ratio is less than the predetermined range, the size of the communication hole becomes too large, and the waterproof performance is inferior to the expected level. If the volume ratio exceeds the above-mentioned predetermined range, the size of the communication hole becomes too small, and the ventilation resistance becomes lower than expected.

The water repellent to be impregnated into the compression-molded body thus obtained is not particularly limited in its kind, and may be, for example, a liquid silicone resin (which may contain silicone oil) or. A liquid fluorine resin (a resin containing a fluorine oil) may be used. These liquid resins are obtained by diluting the resin in an organic solvent such as toluene, xylene or n-hexane. For example, a preferable result is obtained by using a dispersion or a solution having a resin concentration of about 10% by weight. ing. The liquid resin used for the water repellent is preferably a resin having a functional group having adhesiveness to rubber, and a commercially available silicone-based coating agent (HS-3, HS-4, manufactured by Toshiba Silicone Co., Ltd.). ) Can also be used.

In the treatment with the water repellent, the compression molded body is immersed, or preferably, is immersed in a reduced pressure state, or is impregnated into a rubber compression molded body having continuous ventilation holes by applying a well-known coating method such as spraying. Normally, it is sufficient to impregnate a 10% resin concentration liquid of 1/10 volume of the volume ratio of the rubber compression molded body, and the impregnation amount is appropriately increased or decreased according to the rubber material and other conditions. You can do it, for example, 3%
The preferred result was obtained by impregnating 3 ml of a dispersion having a resin concentration of about 10% by weight into a rubber compression molded article having a volume ratio of 1000 ml and a volume ratio of 1000 ml.

After impregnating such a water repellent, it is usually heated and dried, and the resin is further cured. Silicone coating agent (HS-3, HS, manufactured by Toshiba Silicone Co., Ltd.)
When -4) is used, it is dried at 25 ° C. for about 3 minutes,
It is preferable to heat and cure at 100 ° C. for 5 to 10 minutes or at 150 ° C. for about 2 to 5 minutes.

As shown in FIG. 3, in order to manufacture a shoe in which the outside and the inside of the shoe can be ventilated, it is preferable to form a part or the whole of the sole with a breathable waterproof rubber molded body.

In the embodiment of the shoe shown in the figure, the sole 5 is formed integrally with a breathable waterproof rubber molded body, and the upper part 7 is integrally formed thereon with an insole 6 by bonding or sewing. Become

In the sole of the shoe, only the arch portion may be formed of a breathable waterproof rubber molded body, and the other portion may be formed of another material. In this way, the waterproof rubber molded article can be used while avoiding the portion where the waterproof property is easily lost due to the pressurization by the body weight.

[0031]

[Examples and Comparative Examples] [Examples 1 to 3, Comparative Examples 1 and 2] 100 parts by weight of pulverized waste tire powder (Muraoka Rubber Co., Ltd.) having a particle size of 0.5 to 1.7 mm was mixed with liquid 11.5 parts by weight of polybutadiene rubber (MC50, manufactured by Idemitsu Petrochemical Co., Ltd.) and 0.1 part by weight of water were mixed, put into a mold, and placed in a mold.
Compression (0.285 kg / cm ² )
Heat at 20 ° C for 30 minutes, thickness 50mm, diameter 299mm
Of a disk-shaped material, and 10% by weight of a silicone-based water repellent (dispersion manufactured by Toshiba Corporation) was cut into a 6 mm-thick disc at a space ratio of 1%. / 10 volume was used as a guide, and the sample was soaked by dipping, drained, dried and heat-cured.

With respect to each of the obtained test pieces, the waterproof pressure and the ventilation pressure were measured using the test apparatus shown in FIG. 4, and the results are shown in Table 1.

The test apparatus shown in FIG. 4 and the method of measuring the waterproof pressure and the ventilation pressure are as follows.

The test apparatus is a cylindrical pressure vessel 1 having an open top.
0 is fixed to a base (not shown), and a pressure-resistant cylinder 11 for fixing a sample is provided above the base, which can be moved up and down by an air cylinder (not shown). The pressure vessel 10 can measure 0 to 100 hPa. A micro pressure gauge 12 is connected, and an auxiliary pressure vessel 14 is connected via a pipe 13 communicating from the vessel bottom,
An exhaust pipe 16 having an exhaust valve 15 and an air supply pipe 19 for introducing air supplied from a low-pressure air pump 17 of 100 hPa through a pressure reducing valve 18 are connected to the exhaust pipe 16.

<Measurement of waterproof pressure> To measure the waterproof pressure of a test piece (Example and Comparative Example) using this test apparatus,
After the exhaust valve 15 is opened and the pressure vessel 10 is filled with water and water is introduced into the auxiliary pressure vessel 14 through the pipe 13, the exhaust valve 15 is closed. Then, the test piece 20 is placed so as to cover the opening on the upper surface of the pressure vessel 10, the pressure-resistant cylinder 11 for fixing the sample is lowered by an air cylinder, and the test piece 20 is sandwiched between the pressure vessel 10 and the pressure-resistant cylinder 11. Was fixed such that the end faces of the test piece 20 were in close contact with the front and back of the test piece 20 in an airtight manner. Next, the air pump 17 is operated and the pressure reducing valve 1 is operated.
5 was adjusted, and the pressure (hPa) indicated by the micromanometer when water droplets appeared on the surface of the test piece was measured.

<Measurement of Ventilation Pressure> With the exhaust valve 15 closed, the test piece 20 is placed so as to cover the opening of the pressure vessel 10, and the pressure-resistant cylinder 11 is lowered by the operation of the air cylinder, thereby obtaining the test piece. The sample 20 was sandwiched between the pressure vessel 10 and the pressure-resistant cylinder 11, and the end faces were tightly fixed to the front and back surfaces of the test piece 20 in an airtight state. Next, water is poured into the pressure-resistant cylinder 11 to a depth of about 5 mm, and the air pump 17 is started while the pressure reducing valve 18 is squeezed to the maximum. Then, the pressure reducing valve 18 is gradually opened to open the surface of the test piece 20. The pressure at which bubbles began to emerge from almost the entire surface of the sample was measured with a micro-pressure gauge.

[0037]

[Table 1]

As is clear from the results in Table 1, Comparative Examples 1 and 2 in which the compression ratio was out of the predetermined range showed a large variation in the values when the ventilation pressure was less than 5 hPa or more than 30 hPa. In Comparative Examples 1 and 2, the waterproof pressure was less than 20 hPa or 6
The values varied widely beyond 0 hPa.

On the other hand, in Examples 1 to 3 in which the compression ratio was within the predetermined range, the ventilation pressure was appropriately low and the waterproof pressure was high, and it was recognized that the air permeability and the waterproofness were sufficiently exhibited. .

[0040]

As described above, the invention relating to the air-permeable waterproof rubber molded article of the present application is a compression-molded article in which continuous pores are formed by a composition comprising pulverized particles of vulcanized rubber and liquid rubber, Since it is a breathable waterproof rubber molded body with a water-repellent film inside the ventilation hole, it exhibits sufficient breathability and waterproofness regardless of the shape and thickness of the molded body, and it has a practical strength Become.

Further, in the shoe-related invention of the present application, since a part or the whole of the sole is formed by the above-described breathable waterproof rubber molded body, the shoe sole which is easily worn has good durability and breathability. There is an advantage that a shoe that can exhibit waterproofness, has a simple structure, and is easy to manufacture can be provided.

In the invention according to the method for producing a breathable waterproof rubber molded article of the present invention, a prescribed amount of a mixture of pulverized vulcanized rubber particles having a prescribed particle size distribution and a liquid rubber is filled in a mold in a prescribed amount. In addition, since it is a method of compression and compression molding, it has the advantage of being able to efficiently produce a molded body having high practical strength, exhibiting sufficient air permeability and waterproofness regardless of the shape and thickness of the molded body. There is.

[Brief description of the drawings]

FIG. 1A is a partial cross-sectional view of a breathable waterproof rubber molded article according to an embodiment. FIG. 1B is a cross-sectional view showing an enlarged part of the breathable waterproof rubber molded article according to an embodiment.

FIG. 2 is an explanatory view of a waterproof action of a breathable waterproof rubber molded body.

FIG. 3 is an exploded perspective view of the shoe showing the embodiment.

FIG. 4 is an explanatory view of a test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulverized particle 2 Liquid rubber 3 Continuous ventilation hole 4 Water-repellent coating 5 Sole 6 Insole 7 Upper part 10 Pressure vessel 11 Pressure-resistant cylinder 12 Micro pressure gauge 13 Pipe 14 Auxiliary pressure vessel 15 Exhaust valve 16 Exhaust pipe 17 Low pressure air pump 18 Pressure reducing valve 19 Air tube 20 test piece

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 9/42 CEQ C08J 9/42 CEQ // C08J 9/24 9/24 B29K 21:00 B29K 21:00 103: 00 103: 00 B29L 31:50 B29L 31:50 C08L 21:00 C08L 21:00 (72) Inventor Hitoshi Ishikawa 4-4-159-506 Nakaochiai, Suma-ku, Kobe-shi, Hyogo Prefecture (72) Inventor Yama ▼ Saki ▲ Kiyoshi 2014 Futami-cho, Futami-cho, Akashi-shi, Hyogo No.823, San Heights Tsuchiyama No.823 Iida351-7 F term (reference) 4F050 AA01 AA06 BA04 BA25 BA38 HA37 HA53 HA80 4F074 AA05L AA09M AC17 CA52 CC04Y CC32Y CC34Y CE15 CE66 CE83 DA13 DA45 DA59 4F204 AA45 AC01 AC04 AC06 AG20 AH67 AR20 FA01 FB0 1 FF01 FN11 FN16 FW31 FW37 4F212 AA45 AB09 AC04 AG20 AH67 UA04 UB01 UK09 UW26 UW32

Claims (3)

[Claims] 1. A composition in which 5 to 15 parts by weight of liquid rubber is blended with 100 parts by weight of pulverized rubber vulcanized rubber. A breathable waterproof rubber molded article which is compression-molded so as to be formed into a shape and impregnated with a water-repellent agent to form a water-repellent coating inside the continuous ventilation hole. 2. A shoe in which a sole or the whole of a shoe sole is formed from the breathable waterproof rubber molded article according to claim 1, and the outside and the inside of the shoe can be ventilated through the breathable waterproof rubber molded article. . 3. A mold is filled with a mixture of 100 parts by weight of pulverized vulcanized rubber having a particle size distribution of 0.5 to 1.8 mm and 5 to 15 parts by weight of a liquid rubber, and a compression ratio (1 / 2.35). )-(1 /
2.18) A method for producing a gas-permeable waterproof rubber molded article in which the molded article is molded by applying pressure and heating, and then impregnated with a water-repellent agent to form a water-repellent film inside the continuous ventilation hole.