KR101664891B1 - Cork-synthetic rubber vulcanized product - Google Patents

Abstract

The present invention relates to a process for preparing a master batch of an unvulcanized rubber by adding a vulcanizing agent to a mirrorblock synthetic rubber, The master batch and crushed cork pieces are mixed in a mixing roll or a kneader at an upper limit temperature of 155 DEG C to form a cork synthetic rubber mixture, wherein the cork synthetic rubber mixture contains 30 to 150 wt% A second step of additionally mixing; Wherein the cork synthetic rubber mixture is vulcanized to form a vulcanized product, wherein the vulcanized rubber product is vulcanized and vulcanized to form a plurality of vent holes in the vulcanized product, A third step of performing air venting a plurality of times from a time point when the viscosity value is increased to a time point when the viscosity value is increased to 75; , And a cork synthetic rubber vulcanized product in which a plurality of ventilation holes are formed in the vulcanized product and the density thereof is 1 or less uniform and floating in water.

Description

CORK-SYNTHETIC RUBBER VULCANIZED PRODUCT}

The present invention relates to a cork composition for a dynamic field using a high strength of a cork composition, that is, a cork composition for use in a sole, and a static field using the disruption property of a cork composition, that is, Manufacturing technology.

Conventional cork plates (hereinafter referred to as "conventional corks") have the following categories of density of 0.5 ± 0.1 g / mm ³ .

A cork crushing piece as shown in Fig. 1 (A) was coated with a binder of a natural synthetic rubber and a thermoplastic polymer as shown in Fig. 1 (B), mixed without containing a vulcanizing agent and a crosslinking agent, As shown in Fig. 1C, blocks are cemented to each other, and then the cork which has been blocked is sliced to be referred to as "cork plate ".

This is not a vulcanized product but is cured by the pointed force. As shown in Fig. 2C, when the elongation in the directions a and b in Fig. 2, the joint finally breaks down and is dynamically weak.

Therefore, a resin film or a coating has been applied to reinforce the cork surface.

Further, vulcanized rubber containing a cork called "rubber cork" has a specific gravity of 1 ± 0.1 (density: g / mm ³ ), and its end face (including slice plate) There is an increasing number of islands of cork in the sea, and its properties are dominated by rubber, so the inherent characteristics of cork have not been demonstrated.

In addition, in the case of static building materials, the combustibility of the binder is a problem. Combustion of a flame retardant agent, which is a halogen compound, causes oxygen deficiency (carbon monoxide poisoning) in case of fire. Antimony oxide is harmful to human body. And obstructed the spread to the field of architecture.

On the other hand, although the above-mentioned thermoplastic polymer binder is disclosed in Chinese patent application No. 00119861.0 (Japanese Patent Application Laid-Open No. 1285367 (published on February 22, 2001) "Crushed natural wood and rubber synthetic and making method thereof" It is weak and flammable.

China Patent Application No. 00119861.0 Patent Publication No. 1285367 (published Feb. 28, 2001) "Crushed natural wood and rubber synthetic and making method thereof"

The volume of natural cork particles accounts for 95% of the total gas, only 5% of the solids, and is a rare structure with 20 to 40 million cell walls per cubic centimeter (cm ³ ) .

In the " plastic compounding agent " (revised edition of 1974 (digestion 49 years)), in the items of " Properties of the organic filler ", the external appearance has a specific gravity of 0.05 to 0.06, which is very light, excellent in abrasion resistance, oil resistance and compressibility, Which is poorly absorbed and has low volume cost.

The effect is that the cork is extremely porous, so when filled with rubber or vinyl chloride, it is in the same state as "hardened air ". Therefore, it is described that it is useful for weight reduction such as bottom material, cushioning material, soundproofing material, hockey ball, and the like.

However, the cork product with the compounding ratio of 100 phr of the bonded rubber: 100 phr of the cork is still made up of Michalai type and has been limited to use in the static field. The reason is in the suberic acid (suberic acid) (45%) mainly composed of a cork, which is a form of mixed formula C ₆ Hl ₂ (COOH) ₂ of the dicarboxylic acid, cork acid, octane-2 acid.

This carboxyl group (-COOH group) reacts strongly with the inorganic substance and the metal due to heating, so that it is impossible to demold from the mold (conventionally, the explanation of the cause is not reached) The mold is inevitably used. Therefore, conventionally, long-time heating and long-term cooling are required in high crystallinity and thermoplastic unvulcanized polymers.

In the present invention, the cork vulcanized product is a vulcanized rubber composition having a strong block as a whole due to vulcanization, does not require a cooling step, can be easily demoulded, and the production process and production time can be greatly shortened.

In order to solve the above problems, the present invention provides a cork synthetic rubber composition comprising 100 parts by weight of a synthetic rubber, which is a mirrorbapped synthetic rubber, and 30 to 150 parts by weight of a crushed cork kneaded with a crosslinking or vulcanizing agent (Hereinafter referred to as "solids") having a density (g / cm 3) (hereinafter referred to as "specific gravity") of not more than 1 are suspended in water, characterized in that the cork synthetic rubber vulcanizate .

Wherein the synthetic rubber is a group A of a mirror-bladed urethane rubber (hereinafter referred to as 'M / PU') or a diene polymer rubber, and the crushed cork has a particle diameter of 0.2 to 3 mm Fine cork '), and the particle distribution may be in the region of 70 ± 20% (by weight).

As described above, a product obtained by curing a cork synthetic rubber mixture obtained by mixing Group A and crushed cork pieces has a shoe window application in a dynamic field which mainly emphasizes high strength, abrasion resistance, and slip resistance.

In the above description, the synthetic rubber is a chloroprene rubber (hereinafter referred to as "CR") or a group B which is a halogenated rubber, and the crushed cork piece has a particle diameter of 3 to 10 mm (hereinafter referred to as "fine cork" , And the particle distribution may be in the region of 70 +/- 20% (by weight).

As described above, a product obtained by curing a cork synthetic rubber mixture comprising a mixture of Group B and crushed cork fragments has a use for building materials, which is a static field emphasizing mainly weatherability, flame retardancy, heat insulation, soundproofing and sterilization.

In the above, the cork synthetic rubber mixture may be prepared by adding a vulcanizing agent, a reinforcing material, a filler, and other drugs having a specific gravity of 1 or more to the synthetic rubber, and mixing the crushed synthetic rubber with the crushed cork.

As another aspect of the present invention, a mirror-type urethane rubber (hereinafter referred to as 'M / PU') or a group A of a diene polymer rubber and a chloroprene rubber (hereinafter referred to as 'CR' (Hereinafter referred to as 'M / B') of a unvulcanized rubber by adding a vulcanizing agent to a synthetic rubber generally classified into Group B, which is a halogenated rubber, or a vulcanized rubber, C or less at a mixing roll or a kneader to form a cork synthetic rubber mixture by mixing the master batch and the crushed cork pieces, wherein the cork synthetic rubber mixture is mixed with 100 parts by weight of the synthetic rubber, And 30 to 150 parts by weight of the cork synthetic rubber mixture is vulcanized to produce a cork synthetic rubber vulcanized product.

In the above, the cork synthetic rubber mixture may be added with various synthetic rubbers, resin blend, combination of crushed cork particles, blending ratio, synthetic fiber, natural fiber and various chemicals; A transparent flame retardant polymer coating may be provided on the surface of the cork synthetic rubber vulcanized product; Group A may include a vulcanizable block copolymer; The group B may include a flame-retardant silicone rubber and a liquid (one- or two-part) silicone paint.

The following effects are expected by the present invention.

The following are the main drawbacks of the polyurethane sponge (hereinafter referred to as " PU sponge ") used as a conventional shoe sole.

① When the floor is worn out, the bubble becomes a concave part, and on the wet road surface, the water is compressed and exhibits a 'bearing action', which is extremely dangerous in the rain, ice and snow. Regardless of wet road surface, icy snow, or bottom material, the corks take up the menstrual flow through the perforated holes and improve the frictional resistance dramatically.

② It is indispensable to add silica, titanium, and filler which are nuclei of bubbles to the sponge, and these hard fine particles generate an unpleasant sound when they are brushed against the floor. The cork composition of the present invention is expected to provide a solid lightweight substitute for a sponge without generating a fricative.

<Refractory, flame retardant, assembled house>

Conventionally, the use of cork was overwhelmingly building material, and it was heat insulation, soundproofing, cushioning, moisturizing, wall and flooring. However, the architectural standards of flame retardancy have become obstacles to its spread. In the present invention, refractory and flameproofing are formulated by adding no flame retardant, and the ease of transportation is ensured by the lightweight of natural cork together with the general housing material, and it is possible to carry out air discharge (lightweight, ), It is expected that new use of emergency assembled houses (stockpile / withdrawal / expedition / etc.) will be expected.

According to the present invention, it is possible to achieve complete detoxification by the addition of antimony oxide without addition of reinforcement to the surface of the cork, to increase the original exposed cross-sectional area of the cork, to eliminate the factors (adhesive, solvent) It is expected to use new building materials that improve insulation, moisturizing, soundproofing, buffering, insectproofing, anti-mold, anti-static, anti-rust and deodorizing effects.

Conventional plywood for a building material has a permanent hole (scratch) when a nail is stuck. The cork of the present invention is an elastic body of vulcanized rubber (with a low permanent deformation) tightening an open hole, automatically restoring the wound marks, preventing leakage, and maintaining the original aesthetic appearance. Therefore, when a conventional honeycomb, a concrete panel and a tinplate are integrally formed, for example, hot melt is performed simultaneously in the manufacturing process of a conventional product without requiring an adhesive, The product is expected.

1 is a view for explaining a conventional cork plate,
2 is a view for explaining a conventional cork plate,
3 is a view for explaining a honeycomb structure and a brick structure of a natural cork,
4 is a schematic view showing the relationship between the cork and rubber of the present invention,
5 is a sectional view of the flame-retardant testing apparatus of the present invention,
6 shows a test apparatus for evaluating the durability (flexibility) of the present invention,
7 is a cross-sectional view of the impact test apparatus of the &quot; human fracture prevention protector &
8 is a sectional view of a conventional used mold,
9 is a view of a sole window made by the present invention,
Fig. 10 shows the structural formula of naphthalene as a sublimation material,
11 is a curvature curve.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention in the drawings, portions not related to the description are omitted, and like reference numerals are given to similar portions throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

First, the contribution of the cork component to the present invention will be described.

<Cork composition and chemical reaction>

Table 1: Excerpts from the "Cork Ingredients" report of Ken Bridge University in 1981

Cork component constitutional formula Composition ratio (%) Suberic acid
Serine
Friedelin
Wax COOH (CH _{2) 6} COOH
C ₃ H ₇ NO ₃
C ₃₀ H ₅₀ O
CH ₃ (CH _{2) 14} COOH 45%, melting point > 144 DEG C


Melting point 80 ~ 100 ℃ Lignin It is also called phenol-based macromolecule. 27% Cellulose (C ₆ H ₁₀ O ₅ ) n 12% Tannin A plurality of polyphenolics 6% Glycerin C ₃ H ₅ (OH) ₃ 6% Ash Na, Ka, Mg 4%

Suberic acid (suberic acid) is, the present formula C ₆ Hl ₂ (COOH) dicarboxylic acid of _2, cork acid of _{C 8 H 14 O 4, CH} 3 (CH 2) a ₆ COOH octane-2 acid is a mixture of (-COOH group) of the present invention causes a strong bonding reaction to the metal by heating and vulcanization (already well-known), and the carboxyl group (-COOH group) as a main component is taken into the vulcanization apparatus of the present invention And other ingredients were also used for the expression of new functions.

Lignin (27%) Phenolic polymer has flame retardancy and gives tackiness to the unvulcanized rubber as a tackifier. In addition, when added with sulfur, it shows strong adhesion when it is heated. "Lignin rubber" .

In addition, the following three drugs with sulfur added to lignin are marketed (in parentheses, the effect corresponding to rubber is described).

(1) dimethylsulfide / (CH ₃ ) ₂ S (consisting of organic sulfur which is insoluble in water and is responsible for the curing of M / PU and CR of the present invention).

(2) Dimethyl sulfoxide / (CH ₃ ) ₂ SO (It has extremely high hygroscopicity, moisturizes cork porcelain, and increases antistatic function.)

③ Methanethiol / CH ₃ SH

In the present invention, lignin builds a strong bridge at the interface between the cork cells and the vulcanized rubber.

The polygons (12%) are mainly starch and cellulose, and the porous thin wall of Fig. 3 is constructed of the honeycomb structure of e in Fig. 3 and the brick shape of f in Fig. Natural cork is the lightest substance on the ground and is a rare substance with no other similarities. The present invention makes full use of this characteristic.

Tannin (6%) is a polyphenol compound and imparts flame retardancy. The term "tannin" refers to tanning leather in English, indicating the tanning properties of the leather used in tanning, thereby making it possible to save the texture and smell of real leather in the dynamic field of the present invention, .

Nitrocellulose and camphor in the cellulose (5%) ingredient show intense aggressive combustion when ignited. The content of this ingredient is calculated to be only 0.025%. When it approaches the flame, it disappears like a momentary flame. The cells are isolated one by one so that no chain combustion occurs. In the present invention, each unit of cork particles is divided into fire walls of self-inflammation (in particular, CR). By using this special phenomenon and structure, It is realized by burning completely unburned instantly, and it is realized out of common sense.

Historically, camphor (aka: naphthalene) (Naphtalen / C ₁₀ H ₈ ) acts as a natural insect repellant, cellulose (aka celluloid) is the first artificial plastic, celluloids are waterproof and resilient The porous pores of the cells exhibit naphthalene-like antifungal properties. Therefore, the cell wall deformed in the kneading process, the thermal history of the vulcanization (above 100 ° C), the vapor pressure expands the porous hole to restore the cavity, the insecticide is sealed in the cavity, The product exhibits stiffness and insecticidal and sterilizing properties as shown in the structural formula of naphthalene (C ₁₀ H ₈ ) in FIG.

It is regarded as a 'flame retardant substance' as an inverted conception for the phenomenon of intense combustion when ignited for the main component of cork (about 90% of 95%), and other mineral water of 5%, glycerin, It has a water vapor pressure of 4.6 kgf / cm ² at 155 ° C and promotes the chemical reaction of each component in the mold.

<Principle of solution of task>

The mechanism of introduction of a carboxyl group (hereinafter referred to as "X conversion") in the curable (crosslinked) rubber system of the present invention will be described.

As shown in Table 7, A group of synthetic rubbers of claim 2 include commercially available X NBR (Nipol-1072J, DN631) and hydrogenated (hereinafter referred to as "H") HNBR and HSBR, Rollers, adhesives, and adhesives, and the present invention is based on the fact that the use of this product is under consideration. The vulcanized rubber of the present invention is made into a mechanism of high physical property expression by corking and vulcanizing.

In the present invention, it has been clarified that the vulcanized rubber method can not be applied in the prior art because the strong functional bonding of the X functional group contained in the cork component with the metal surface has been explained. Thus, M / PU of group A of claim 2; 10.0 (cal / cm &lt; ³ &^gt;) ^1/2 and CR of group B; σ10.0 solubility constant of (cal / cm ^{3) 1/2,} the preceding paragraph, X and H Chemistry Chemistry NBR; (SP value: sigma) of 9.90 to 9.83 (cal / cm ³ ) ^1/2 (SP value: sigma), which tend to easily melt and mix with each other and are extremely easy to introduce X and Y groups into the polymer And is a basis for the mechanism of high physical property expression of the vulcanization system of the present invention. And selects M / PU and CR shown in Tables 2 to 5 where the SP value is approximate.

The mineral water of 5% is steamed at the time of vulcanization, and the cell hole of the crushed cork is automatically restored without adding a new foaming agent. The cell wall is restored elasticity, Even if bent at 180 degrees of the bending strength, the bending number of times is more than 20 times.

Since the CR composition of the present invention is mixed with a coarse cork (crushed cork having a particle diameter of 3 to 10 mm), the granular region shown in Table 6 is used at 70 to 93 占 폚, Mixing work was employed to prevent cork destruction in unloaded agitation, such as mixing jars with sugar.

Conventionally, cork products require a long time from heating to cooling. However, there is a history that molding has been made using wood molds. This is because the reaction of X and H is not known and the wood mold has been empirically used. The present invention is accomplished by a single vulcanization in the molding of a mold, and realizes a considerable reduction in time. In addition, the problem of demoulding was solved at the same time by adopting a new method of heating the uncooked raw material in a heat oven (accelerating the vulcanization) and molding it in the compression type of "super engineering plastics".

The second component, lignin (27%), imparts an appropriate tackiness to the unvulcanized rubber as a tackifier and facilitates bonding with the cork particles, especially when sulfur is added to heat the tackifier to become a strong adhesive , Which has traditionally been regarded as "lignin rubber ", which was introduced into the cork dispersion and particle interlocking strengthening of the present invention as a means of strengthening the cork vulcanizates of the present invention.

The third component, tannin (6%), is applied to high-class shoe sole that imparts the color and smell of leather (tanned leather) and realizes the texture of leather. The cut surface is modified by the difference between the mix and the color tone of the particle size distribution shown in Fig. 4 as an array (Fig. 3) g of the spores hole (2000 man ~ 4000 man / cm ³⁾ of the fine cork particles, natural texture and lightness Thus, each portion of genuine leather is different in quality, thickness and hardness, but the present invention has a uniform hardness and thickness, resulting in economical effect of effective cutting area.

The polymeric catalyst of CR and M / PU of the present invention, the chlorine group of CR, and the metal ions of ZnO, MgO, which are common compounding agents, are the components (5%) of the cork of the present invention, protein in tannin, complex of alkaloid Complexes), Na, Ka, and Mg ash are deeply related to the polymers listed in Table 7, which is a catalyst for the formation of H (M / PU and CR) functional groups.

In addition, cellulose (5%) is a waterproofing agent that is commonly present in the vegetable field. In the present invention, it is a waterproof wall that combines restoration of rigidity and elasticity by bubble expansion action and is a component responsible for the fire resistance of instantaneous combustion.

Complex aromatic compounds and proteins with many phenolic hydroxyl groups are decomposed at the vulcanization temperature and the color of the crushed fiber changes subtly over several turns to give rise to the frost descending type peculiar to natural leather, The wax (WAX) treatment allows the wax (WAX) to penetrate into the cross section and add gloss and water repellency.

Conventionally, the cork has a construction interior that is mainly used, but in the present invention, in principle, it is not necessary to reinforce the film (impregnated resin) and exposes the cross section of the cork particles. In the indoor use, the wall material breathe, (Active) action.

The 'rubber solids floating on the water' floor has been considered to be unreasonable in modern technology, but it is possible to provide a light weight of the 'solid' of the present invention in place of the sneaker (sponge) do.

The mold used in the press forming of the present invention may be in use or used. However, since it is recognized as inorganic and metal when it is contaminated or rusted, it is treated as a mold release agent, abrasive, surface active, and fluorine type release agent by sand blast, and even new products, such as machine oil, are attached to polytetrafluoroethylene tetrafluoroethylene) processing is also applied.

Description of Means for Solving the Problems [

M / PU 'M / B' (specific gravity 1.2) and CR 'M / B' (specific gravity 1.3) of the basic formulation are assumed to be 0.2, The weight of the cork was calculated as 30 parts by weight of the lower limit weight of cork per 100 parts by weight of M / B 'and 150 parts by weight of the upper limit weight. The weight of cork was 1 or less as specified in claim 1 (specifically, 0.96 to 0.5 g / cc ) And becomes a solid vulcanization product floating in water.

The term "millable type" as used in claim 1 or 2 means a rollable polymer in the rubber industry. M / B of the present invention requires calendaring, sheet forming and roll operations, The M / PU and CR of Table 3 and Table 4 have abrasion resistance and dynamic strength in the dynamic field, and Table 3 and Table 7 show that the M / PU and CR of the polymer satisfy the conditions of kneading The CR in Table 5 has excellent bonding properties to the balance of flame retardancy, weatherability, chemical resistance and durability of the present invention in static fields, and is a polymer representative of the use of Group B of the present invention .

The 'synthetic rubber' of claims 1 and 2 refers to chlorinated rubber such as chlorosulphonated polyethylene (CSM), vinylidene fluoride (FKM), tetrafluoromethyl vinyl ether FFKM), tetrafluoroethylene-propylene-based, epichlorohydrin rubber (CO), and the like, and fluorine-based and silicone-based paints and coatings of Group B of Table 12 are used for outdoor purposes for outdoor use.

In Table 7, there are shown representative commercial carboxyl-containing and hydrogenated (commercially available) commercially available rubber products of Japan, which significantly modify M / PU and CR, and the CR (Skyprene) carboxyl group denaturing grade of TOSOH CORPORATION and the Latex type GLF -280 and 890 are said to have an excellent effect on the use of the adhesive of the product of the present invention. Group A and Group B of the present invention are broadly referred to as 'synthetic rubber'. The parentheses show the ASTM abbreviation.

The M / B produced in the first step of the fifth aspect of the present invention is intended to complete the dispersion of the vulcanizing agent and the compounding agent in the cooling roll. In the rubber composition of the present invention, in the vulcanization system, If the cork system in which the cork particles are mixed in advance is added later, it takes time to disperse, the cork is broken, the roll is raised and lowered by the shear friction, scorch (initial corking) If the roll gap is wide, the raw paper is not wound and the dispersion is poor. If the roll interval is narrow, the cork is destroyed and the hot history of the high temperature is burned, and the sheet can not be realistically realized. Therefore, in order to solve this problem, the present invention employs a two-step dough process of the first and second processes.

In the present invention, the cork particles once cracked and compressed in a roll and a kneader are thermally expanded in the press so as to be sealed in the mold. As the vulcanization progresses, the combined rubber retains the mesh structure And then hardened. In the present invention, first, the press pressure is reduced several times within a time of t _s 35M to t _s 85M rising from Vm showing the lowest value of the Mooney viscosity in the curvature curve of the vulcanization temperature, and the internal residual gas is completely released (Air depressed), and continues to pressurize to full vulcanization.

In the present invention, when the rubber film concealing the cork is in the state of vulcanization, the residual gas at high pressure breaks through the concealing film and simultaneously releases the gas in the cell, and the gas locus of the semi- . In addition, the inside of the molded article is stored and completely vulcanized to the central portion with the lapse of time. The product at room temperature can also be solidified and processed by a woodworking machine. (In the past, cork exhibited sticking while the binder was thermally softened and this work was impossible.)

On the other hand, halogenated IIR and Polynor-Boonen (NOX) can be used as synthetic rubber for impact absorption (low rebound material). Specific examples of applications include a landing mat for gymnastics and a protector for preventing human fracture. Table 10 shows the processing conditions in the example formulations and reference columns.

If the sea (low rebound rubber) shown in Fig. 4 (g) slowly attenuates the impact of high energy and reaches a compressibility of 50% and the island (cork) is densified, this time, It becomes a repulsive action, and the skeleton inside the protector is protected. In other words, it becomes a cork product for cushioning which has no precedent in absorbing and repelling.

When manufactured for shock absorbing purposes, it can be used as a safety cover for various supports such as steel bars, baskets and golf net of schools, as a buffer underlayment mat for induction mat, and as an armor for kendo. Also, a ball with a high air resistance and no flying, light and hard ball can be an indoor training ball, a narrow ground ball, and a safety ball for young children. That is, the conventional cushioning material is in the form of a soft gel or a thick sponge, whereas the present invention is the opposite of the conventional cushioning. This unprecedented 'cork cushion material' is a high-load, high-impact sports glove (soccer shin guards, kendo's face, torso, arm cover, helmet), human body protection, etc., which are not stretched, distorted, distorted, And to contribute to the creation of

BEST MODE FOR CARRYING OUT THE INVENTION <

When the cross section of the cork particle is exposed by grinding and slicing the surface of the cork, the perforated hole is calculated as 20 ^{x 10} to 40 ^{x 10} per square meter. The perforated holes in Fig. 3 (e) are responsible for respiration of humidification and drying, and are harmless to human beings and livestock. The light properties of flame retardancy are: ① inside of ship, interior of submersible, ② floor plate, wall, Insulation, bending elasticity) are suitable for building materials of earthquake-proof property, and ③ coat the coating of the present invention if necessary.

This cork has a characteristic that it can be formed into a multilayer without any adhesive, and if a certain number of aramid fiber net is installed between these layers, high strength of the level of ④ bulletproof vest can be obtained, and ⑤ a small mesh The electromagnetic waves interfere with each other, for example, as an electromagnetic interference material of a linear train, and (6) when applied to an aluminum foil, it shields the radiation of the spacecraft, , And ultrasound shielding, and if combined, it becomes a defensive system by disturbing the direction of the reflected wave without interfering with the radar, instead of being caught by radar instead of ⑦ stealth, ⑧ contributing to the highest level of shelter structure or new field of space development .

This cork has new uses in the methane hydrate, natural gas and petroleum mining plants of marine facilities due to its non-sinking and floating nature. ⑩ If a combination of carbon fibers or a pipe-shaped hollow steel material is contained in a cork, (12) It is hard to bend when it is thickened in the high pressure press, and it has high elasticity at high stress, and it is a high-strength holding material excellent in durability. (13) Although artificial synthetic materials are considered to be 100% impossible in the present technology due to the tsunami countermeasures, deep seas, lifeboats, boats, etc., natural cork contributes to deep sea space industry by creating the technology of the present invention.

The slip resistance on the wet road surface is caused by a physical law called &quot; water film interposed between mutually abrading materials reduces friction. &Quot; In the cork perforation holes of n units (e and f in Fig. ⑭ It has the same frictional resistance as when dried (no water intervening). ⑭ It prevents slippage of the shoe soles, pool sides and hot springs of fishing boat workers, and the disinfection of regular disinfectants to food and medicine factories. There is an obligation, and it is possible to cope with the safety of hazardous wet tiles.

<Examples>

Table 2 shows the master arrangement of the embodiment of the present invention.

M / PU uses MILLATHANE (# 6010), and Table 3 shows a representative commercial product Mirasen (TES.Industries, INC product) of A group. The name of the product.

The present invention is also applicable to any commercially available mirror-bladed urethane of sulfur or peroxidic vulcanization other than the above.

The CR of group B in Table 2 is the trade name of Dupont Dow Elastomers, LLC of Showa Denki, USA, and trade name: Neoprene (trade name) available from Showa Denko Co., Etc. may be applied.

Table 2 shows the basic composition of the master batches of M / PU and CR of the present invention, and Table 2-1 shows an example of the formulation.

Basic blend of group A PHR Basic combination of group B PHR The polymer shown in Table 12 100 The polymer shown in Table 12 100 ZnO (activator) 5 to 50 ZnO (activator) 5 to 50 Stearic acid 0.2 to 2 Stearic acid 0.2 to 2 Sulfur or peroxide 0.5 to 4 Sulfur or peroxide 0.5 to 4 Vulcanization accelerating agent 0-5 Vulcanization accelerating agent 0-5 reinforcement 0 to 60 reinforcement 0 to 60 filling 0-100 filling 0-100 Other 0-100 Other 0-100

<Table 2-1>

Group A is mixed with 30 to 150 parts by weight of crushed cork pieces having a diameter of 0.2 to 3 mm with respect to 100 parts by weight of the polymer and 30 to 150 parts by weight of crushed cork pieces having a diameter of 3 to 10 mm with respect to 100 parts by weight of the polymer.

<Table 3> Miracene Mirrorb Type Polyurethane Series

Product Name Furtherance Vulcanizer Mirasen 76 Polyester type Sulfur / peroxide Mirasen HT Polyester type Sulfur / peroxide Mirachen 66 Polyester type peroxide Mirasen 5004 Polyester type peroxide Mirachen E-34 Polyether type Sulfur / peroxide Mirachen 97 Polyether type peroxide Mirasen CM Polyether type Sulfur / peroxide Mirachen E Polyether type Sulfur / peroxide Mirasen 26 Polyether type peroxide Mirasen 28 Polyester type peroxide

<Table 4> SAKAI CHEMICAL CORPORATION Mirror Beam Urethane Rubber Series

Product Name Furtherance Vulcanizer UN-168 Polyester type peroxide 557 Urutoruru Polyester & Polycarbonate peroxide UN-560 Polyester & Polycarbonate peroxide UN-278 Polyether type Sulfur / peroxide

<Table 5> Grade of showplan (Showa Denko Co., Ltd.)

grade Mooney viscosity
[ML1 + 4/100 DEG C] Crystallization speed Remarks G type (sulfur-modified) GS 40-54 Slightly slow It is the basic grade among sulfur-modified type. Dynamic specificity such as tear strength and flexural strength is good GRT 40-54 Slow It is suitable for friction because the tuck is the best in the good G type of low temperature. SND16 32-52 Slow Low viscosity grade of GTR GW 34-52 Slow As one of the sulfur-denatured types, grades having improved heat resistance and compression set resistance W type (general) W 42-51 Middle The most common grade WM1 34-41 Middle W has a low viscosity grade and has good fluidity WHV 100-130 Middle W as a high viscosity grade for high filling formulation and adhesive WHV100 95-105 Middle WHV low grade grade W type (preferable crystallinity) WXJ 42-51 Abnormally slow Good W type with low temperature. Standard Edition SND6 67-78 Abnormally slow High viscosity grade of WXJ. Adhesion improvement SND8 32-37 Extremely slow W type with the best low temperature flexibility W type (extrusion, calendering) WB 42-51 Middle Excellent grade of extrusion and calendering WXK 73-89 Slightly slow High viscosity grade with good low temperature properties and good extrusion processability. WXKT 106-117 Slightly slow As a high viscosity grade of WXK, SND37 73-89 Slightly slow The extrusion processability is better than that of WXK and the mold staining property is good W type (preferable mold staining property) WK 42-51 Middle A grade that improved the stain resistance of my mold. Roll processability is good WXJK 42-51 Abnormally slow WXJ has improved the mold stain resistance. Roll processability is good
Improved low temperature and WRT grade SND35 63-73 Extremely slow High durability with high viscosity type of SN35, good mold stain resistance SND43 78-88 Extremely slow Grade with improved low-temperature embrittlement property of SN35.It is excellent in mold stain resistance than SND35 and suitable for injection molding. SND45 60-73 Extremely slow Good extrusion, calendering processability, good strength TTVPES (extrusion, calendering / preferred strength) TW 42-51 Middle High viscosity grade of TW TW100 85-102 Middle Grade with better workability than TW with lower temperature SND22 42-51 Abnormally slow Good grade with resistance to crushing (crushing) SND48 85-100 Abnormally slow Excellent in extrusion, calendering TRT 42-51 Extremely slow The most excellent low temperature and good processability

Table 6 shows the characteristics of the temperature range of CR. It is possible to avoid shear fracture of the crushing cork piece by employing the dough processing inherent to the present invention.

<Table 6> Properties of temperature range of chloroprene rubber (Rubber Industry Guide: 4th edition) 269P, Table 10-10

Area Characteristics Sulfur-modified type Non-sulfur modified type Elastic phase 20 ~ 70 ℃ 20 ~ 80 ℃ Mouth imagination 70 ~ 93 ℃ 80 ~ 93 ℃ Plasticity phase 93 ℃ or higher 93 ℃ or higher

The vulcanization of CR is the same as that of the diene monomer unit (-CH ₂ -CH = CH-CH ₂ -), and the compounding agent shown in Table 2 is kneaded while cooling water to 20-80 ° C or lower in an open roll The sheet was placed in a sheet having a thickness of 5 mm to prepare the M / B of the present invention.

<Table 7> shows the typical commercial rubber of carboxyl group and hydrogenation (water addition), and notes the characteristic use contributing to the remarks in the remarks column.

Carboxyl group
XNBR Features or uses Hydrogenation (water addition)
HNBR & HSBR Features or uses Nipol 1072j
Nipol DN631
Nipol DN601
Nipol FN3703 Abrasion and high strength
O-rings, belts, rollers, adhesives, modifiers Zetpol 0020
Zetpol 1020
Zetpol 2020
Zetpol 3120 Sulfur / peroxide
Organic solvent, fuel hose, belt, roller, ozone Carboxyl group XCR
Skyprene (TOSOH CORPORATION)
510 (L) 580 (H) Excellent in high temperature adhesive strength and heat resistance. HSBR 1320P
HSBR 1910P Resin modifier, impact resistance
Improvement, softening, transparency (TOSOH CORPORATION)
XCR-Latex
GFL-280
GLF-890 High Adhesive (Adhesion after Drying) Propylene / water (water) addition SBR H4800N
H4900N
H4100N Excellent transparency, flexibility, calendering, stationery, food containers, medical supplies

<Kneading of fine cork>

In the mixing method of the fine cork, first, an open roll of 16x42 (in) was used, the gap between the two rolls was set to 2 mm or less, 5 kg of M / PU (M / B) was wrapped around the entire roll, , 5 kg of fine cork was divided into five equal parts, and 2 kg was added to the first part. The mixture was kneaded without kneading, and 1 kg of the second part was kneaded at a roller interval of 3 mm. 1 kg (roll interval: 4 mm) 1 kg (roll interval: 5 mm) of the fourth turn was added, and a total amount of 5 kg was put therein. While the dough was being changed, the dough was removed from the roll without leaving the dropped cork on the receiving dish, 4 (g) shows a state in which the island (cork) is finely ground with respect to the sea (rubber), and the gaps It shows dispersed state in distance.

<Molding type of fine cork>

Fig. 8 shows a conventional used mold "shinshairu" (pollution wiping, surface treatment). In each mold size, 1/2 of the weight of the molded bottom (one foot) of the master batch of the present invention is the injection amount of the present invention , The specific gravity of the sole of the shoe sole is 0.5 + - 0.1. In the case of the No.1 formulation of Table 13, the seat-sheeting sheet is fine-adjusted to 70 g / The vulcanization was performed at a pressure of 150 kgf / cm ² at 165 ° C for 7 minutes and 30 seconds to prepare a sole. The vulcanization procedure was carried out twice from 30 seconds to twice to 6 minutes, and after 7 minutes and 30 seconds in total, each size was demolded in the form of bari.

Immediately thereafter, the molding window was placed on a steel plate, and a heavy lid (steel plate / 2 mm like the size of the mold) was applied from the top and cooled to the next molding to prevent deformation. This was repeated ten times, and the average of each group was 40 ± 2 g (the measured value was written in), and the specific gravity of this product was finished to about 0.6.

&Lt; Kneading of coarse cork &

12.5 kg of CR (M / B) was stopped by stopping the water cooling of the kneader (50 L), instead, steam was passed through at a temperature of 100 ° C or more and heat was applied. 12.5 kg of a cork Kneaded for 10 minutes while controlling the temperature at 80 캜. At this time, the mixed form shows that the CR is attached to the cork surface of Fig. 4 h in a granular state as a whole. This is taken out into a large box made of polyethylene and rolled up to an elastic phase at a temperature of 70 DEG C or lower when the roll gap is made 4 mm and once passed through an open roll. The sea (rubber) in Fig. 4I is a mesh- ) And an island (cork) are joined and fall down to the bottom of the roll in a sheet form. The sheet of the injection-molded cork composition was divided into four equal parts, which were formed into a cloth shape, and were formed into sheets having a thickness of 4.5 mm and a width of 910 mm by two to four roll passes.

 When the sheet came into contact with air, the surface became barely touchable within a few minutes, and it was cut into a square of 908x908x4.5mm (the weight of one sheet was 3710g ±).

<Molding Type of Coarse Coil>

The inside dimension of the mold frame is 910x910x20mm, and the upper and lower (lid and bottom) plate dimensions are 100x100x5mm aluminum steel mold combined with PTFE surface treatment.

<Insertion amount of entry point cork>

The mold volume was 16,562 cc, the specific gravity of the cork molded article was 0.455, and the scale of the scale was set to 7453 g, and the cork was adjusted in two pieces of the cut sheets. All weights of the present invention are weighted.

<Molding of the cork plate>

<Jomok formulated amount of cork> in the metering sheet press pressure and formulated in <jomok mold of cork>, using a larger (5) Steam pressing of myeonban 1200x1200 150Kgf / cm ^2, the vapor pressure in 4.6Kgf / cm ² in accordance with (10 minutes to 15 minutes to 20 minutes / 2 times each) were taken for 22 minutes. The extruded plate was 910x910x20mm and the reduction after natural cooling (10 hours) was 1.2% . (In the example, three times in one-stage press).

The cork plate aged for 10 hours in the previous section left warmth and it was easy to skydive by slicing (20 pieces) in the skyder machine for sponge. However, when the band saw blade marks appear in a wave shape, the 2 mm thick sheet is changed to a 1.5 mm thick mold under the same conditions as the preceding press, and the vulcanization for 90 seconds is further performed, so that the blade marks and the partial pinholes disappear , And the surface was smoothed, and it was possible to unify to a thickness of about 2 mm.

A hot-melt sheet was attached to both sides of the cork 2 mm plate to form a square of 900 x 900 mm in the pull-out type. It is mainly provided for wall and veneer plates and is made to be the size of a veneer plate called a 90x180 cm triple plate of 900x1800 mm (3 characters x 6 characters) by two pieces.

In the examples, a CR latex (Showa Denko Co., Ltd.) showprene (LD) grade / SD78) was applied with a brush and dried to prepare a vulcanized flame-retardant test piece (100x200 mm).

5 is a cross-sectional view of the flame-retardant testing apparatus of the present invention. A candle (2) (length 60 mm, deep 10 mm, 6 mm?) Was installed in the glass water tank 1, and the tip of the flame was contacted with the cork test piece (3) The interval 4 was set to 10 mm, and the circulation of the air was ensured by interposing the round bar 5 therebetween.

The candle is manufactured by Kameyama Co. (burning time: about 19 minutes), and it is ignited as a lighter in the core, the flame spreads in the form of a circle in the form of a cork, (About 20 minutes), and the combustion test of the present invention was conducted.

Table 8 shows the results obtained in accordance with the above test method.

No. (Abbreviation for ASTM) Polymer molecular structure Salt (A to D) Remarks No.1 market (NBR)

D
Complete combustion (collapse) Cork diameter 3mm No.2 market (TPA)

D
Complete combustion (collapse) China patent disclosure CN1285367 No.3 Example (CR)

A
Carbonization trace Small diameter 22mm The present invention (static use) NO.4 Embodiment (M / PU)
R, R ', R "alkyl group
R '''phenylnaphtho

C ~ D
Flame through hole. Invention (Dynamic use): Solid lightweight window No.5 PolynorBoonen (NOX)

B to C
Carbonized trail 35mm diameter
Some through holes. The present invention (Examples): High shock absorption

Fig. 6 shows a test apparatus for evaluating the durability (flexibility) of the present invention. Sectional view in which a wooden base 1, a transparent acrylic plate 2 and a hinge 3 are attached to each other and a test piece is fixed inside and both ends are fixed by a CR latex 5. Sectional view in a state of bending in the direction of the arrow.

In the present invention, a specimen having a thickness of 1.5 mm (50 x 100 mm) was bent 180 °, and the breakage occurred and the number of cuts was evaluated as durability. The upper transparent plate is for observing the shape of breakage on the way.

Table 9 shows the results obtained in Fig.

No. (sample) Particle Diameter / Thickness Broken
collection Observation of course progress No. 1A commercial Diameter 2mm / thickness 3mm plate 1 time 90 ° cracking / Cutting into two parts at 180 °       B commercial Diameter 3mm / thickness 3mm plate 1 time Homology / homology       C marketed product Diameter 5mm / thickness 3mm plate 1 time Same as above / Same as above + Rubber white papers       D commercially available Diameter 2 ~ 5mm / thickness 3mm plate 1 time Same as above / Same as above + Rubber white papers No.2 (TPA) Diameter 5mm / thickness 3mm plate More than 20 times clear NO.3 (CR): The present invention Diameter 5mm / thickness 3mm plate More than 20 times Part of the cork tends to have a tendency to crack and bend No.4 (MPU): Original invention Diameter 2mm / thickness 3mm plate More than 20 times clear No.5 (NOX) Example Diameter 2mm / thickness 3mm plate More than 20 times No abnormality (tend to bake)

Table 10 shows the NORSOREX formulation of the unprecedented "new cork cushioning material" and the process of making a slice plate of 245x345x5 mm showing the machining and vulcanization conditions in the remarks column.

Compound material PHR Remarks (Processing conditions) NOX NS 70 Niddle (1ℓ) Moriyama Works
- Blending and kneading
417 g x 2 = 832 g except for the vulcanization system
The mixture was kneaded at a storage temperature of 90 ° C for 5 minutes
to the next,
10.5 g of the residual vulcanizing agent in an 8 x 16 in water-
Mix and knead,
300 g of fine cork were mixed at a roll interval of 5 mm,
The sheet was sheeted in a 5 mm sheet at a roll temperature of 110 占 폚.
- Vulgar condition
Mold dimensions: 245x345x20mm to 845g
Were weighed and used as injection quantity.
Press condition: 165 DEG C x20 minutes
The molded plate was sliced to a thickness of 5 mm. Chiorobutyl 2245 30 Naphthene shintaku HA35 250 En-Para K-65 30 Stearic acid 5 Aluminum hydroxide
(Heidi Light H-40) 2 Zno # 3 5 VN-3 30 CZ 3 D One brimstone 1.5 Sum
427.5 Micro cork 300 total
727.5

Table 11 shows the Japanese peroxide cure of the preferred half life temperature of the M / PU of the present invention and is particularly applicable to the incorporation of polyurethane sponge sole.

product name Half-life (℃) Company Name Phexa 3M 90-95 NOF CORPORATION Fabtil D 126-124 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK) Fabtil C 120 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK) Park Meiru D / Kayakumiru 117 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK) Pakhexa 25B / Kayahekisa AD 118 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK) Pakhexa 2,5B / Kaya Heckisa YD 127-135 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK) Peroximone F / Parkadox 14 127 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK) Fabtil I / Kayakarbon BIC 98-98 NOF CORPORATION, KAYAKU AKZO CORPORATION (AKZO KK)

Table 12 shows the base polymers of group A and group B as set forth in claim 2, and Table 13 shows a list of the results of the test results for each application. Inspection institution: Korea Institute of Footwear & Leather Technology, "KSM" standard. In the running formulation, 100 parts by weight of cork (0.2 mm in diameter and 3 mm in diameter) were mixed with 100 parts by weight of the base polymer in the master batch of Table 1.

Table 13 shows a list of physical properties of the polymer blends (100 phr of cork at 100 phr of Table 2 and Table 2-1), a test of changing the polymer type, cork phr and particle diameter It shows the physical properties of the material.

The test institute is Korea Institute of Footwear & Leather Technology and tested according to KSM standard.

Conventionally, cork was not measurable in the dynamic test items of KS M ISO 1798: 2007, KS M 6783: 2009, KS M 6625: 2003.

This demonstrates the robustness of the mechanical strength of the main body.

Group A diene polymer (ASTM abbreviation) Group B halogenated polymers (ASTM abbreviation) Styrene butadiene copolymer (SBR) Polychloroprene (CR) High sis polybutadiene JSR (RB) Fluorocarbon rubber (FKM) (FFKM) Acrylonitrile butadiene copolymer (NBR) Epichlorohydrin rubber (CO) Ethylene propylene copolymer (EPM, EPDM) Silicone rubber (platinum catalyst crosslinking) Polyisoprene (IR) Monomethyl-based silicone varnish Isopentylene isoprene copolymer (IIR) Fluoro silicone rubber (UL approved) Mirrored urethane rubber (U) PVC (polyvinyl chloride) * For poly blending with NBR

Base polymer HS
(C) TB
(MPa) EB
(%) TR
(N / mm) Sg
(kg / m3) Abrasion:
NBS TEST
(KSN :) No.1 CR (WHV) 79 0.95 47 8.59 0.60 18 6518: 2007 No.2
XNBR 75 2.14 63 9.96 0.58 23 6518: 2007 No.3 HNBR / PVC 75 1.55 202 17.8 0.66 39 1798: 2007 No.4
M / PU 80 1.35 35 10.3 0.55 26 1798: 2007 Diameter 3mm Cork No.1, No.4 Diameter 0.2mm Cork No.2, No.3

sample PHR Hardness
KS M 6518: 2008 Tensile Strength
KS M ISO 1798: 2007 Elongation
KS M ISO 1798: 2007 Tear strength
KS M 6783: 2009 Specific gravity
KS M 6660: 2006 ABRASION
KS M 6625: 2003 CR: WHV
Cork (3mm) 100
100 C79 0.95
(MPa) 47% 8.59
(N / mm) 0.60 18% xNBR (A)
xNBR (B)
Liquid xNBR
Cork (0.2mm) 60
40
3
100 C75 2.14
(MPa) 63% 9.95
(N / mm) 0.58 23% HNBR
PVC
Cork (0.2mm) 100
50
100 C75 1.55
(MPa) 202% 17.8
(N / mm) 0.66 39% * 1 Asahikasei
TuprenA
Tupren435
Cork (5mm)
50
50
70 C87 4.01
(MPa) 38% 20.3
(N / mm) 0.79 32% * 2 Asahikasei
TuprenA
Tupren435
Cork (5mm)
50
50
30 C92 3.33
(MPa) 45% 25.4
(N / mm) 0.87 44% MILLATHANE: CM
TiO ₂
Cork (3mm)
Dicumylpreoxide (40%) 100
50
100
2 C80 1.35
(MPa) 35% 10.3
(N / mm) 0.56 16%

The transparent flame retardant polymer of claim 6 is useful for outdoor use because the surface is not contaminated and the fireproof and waterproof layer is strengthened by the coating of the coating of the group B silicone rubber with the platinum compound and the coating of the monomethyl silicone varnish.

7 is a cross-sectional view of the impact test apparatus of the &quot; human fracture prevention protector ".

Comparative samples: gel rubber, foam sponge, CR sponge, conventional cork, base cork,

A glass plate "JIS-3203-1999" 440x440x2 mm was placed under a test plate (dimension 170 × 115 × 5 mm), and the weight of the weight of the lower glass plate was determined as the breaking energy by using each pinch (light to heavy).

DESCRIPTION OF THE DRAWINGS [

1: Bundle (Replacement)

(Diameter: 50 mm, 90 g), rods (2400 g / 3 mm diameter) (4270 g / 4 mm diameter) (6670 g / 5 mm diameter)

2: Drop position: Adjustable up to 120cm or less

3: Transparent container (acrylic material: inner diameter 55mm)

4: Test version

5: Glass plate

6: Urethane open-cell foam sponge (30 times foaming, thickness 20 mm)

7: Base (iron 30mm)

8,

Size 25cm: It shows the cross section of the used mold of the sole.

1: cover, 2: lower mold body, 3 and 5: design, 4: knock, 6: knock guide, 7:

9 is a cross-sectional view of a molded sole according to the present invention.

1: a floor plan of a heel design, and 2: a sole chair.

<Fig. 10> shows a structural formula of naphthalene which is a sublimation material. Wardrobe insecticide, and zine insecticide, the following operations are carried out in order to further maintain the effect of insecticidal and sterilizing described in claim 4.

A curvature curve is shown in Fig. The vertical axis M shows the rise (viscosity) of the Mooney viscosity, and the horizontal axis shows the vulcanization time.

The normal air purge is to purge the residual air contained in the raw paper in the low viscosity region within t1 to t35.

On the other hand, it is preferable that the present invention is carried out in the range of t35 to t85 (from the lowest value of the ununiformity viscosity at the time of vulcanization to the time when the ununnity viscosity value is increased from 35 to 85) (Operation from the time t55 to t75) (from the lowest value of the Mooney viscosity at the time of vulcanization to the time when the Mooney viscosity value increased from 55 to 75) Conduct. That is, the present invention aims to make a number of ventilation holes in a film containing the coke-containing particles without purposing for ventilation.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the embodiments described above are intended to be illustrative, but not limiting, in all respects. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (2)

A first step of preparing a master batch of unvulcanized rubber by adding a vulcanizing agent to the mirrorblock synthetic rubber;
The master batch and crushed cork pieces are mixed in a mixing roll or a kneader at an upper limit temperature of 155 DEG C to form a cork synthetic rubber mixture, wherein the cork synthetic rubber mixture contains 30 to 150 wt% A second step of additionally mixing;
Wherein the cork synthetic rubber mixture is vulcanized to form a vulcanized product, wherein the vulcanized rubber product is vulcanized and vulcanized to form a plurality of vent holes in the vulcanized product, A third step of performing air venting a plurality of times from a time point when the viscosity value is increased to a time point when the viscosity value is increased to 75;
And a second step of forming a second layer on the second layer,
Characterized in that a plurality of ventilation holes are formed in the vulcanization-molded product, and the density is 1 g / cm ³ or less, and the product is floatable in water.
The method according to claim 1,
Wherein the mirrorblock synthetic rubber is any one of a group A of a mirror-bladed urethane rubber or a diene polymer rubber and a group B of a chloroprene rubber or a halogenated rubber.

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