JPH0658466A - Gas rubber tube processed for ratproofing - Google Patents

Abstract

PURPOSE:To prevent any rat-bite damage from occurring by micro-capsulizing a rat-repellent, making a genus of capsaicin an effective ingredient, and adding it to a rubber tube material. CONSTITUTION:A microcapsule agent made up as an effective ingredient after mixing one type or more than two types of capsaicins to be shown in a formula I, is added to rubber tube material, especially to composite rubber tube type outer layer resin 4. This effective ingredient value should be set to 1-2.0wt.%. In this connection, R in the formula I shows an alkyl group of carbon number 7-12, an alkinyl group and an alkenyl group. With this capsaicin micro- capsulized, any drop in resolution and dissipation in a working process is prevented from occurring while its pungent stimulus can be made so as not to give it to an operator, thus its handling becomes facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber tube for gas, which has been rodent-proofed to prevent biting by mice.

[0002]

2. Description of the Related Art A rubber tube for gas is used for connection between a gas plug installed indoors and a gas appliance, such as a multi-layer rubber tube made of all-rubber and a composite rubber tube of inner layer rubber and outer layer resin. To be For such a rubber tube, gas leakage is the most important characteristic. However, conventional rubber pipes are not provided with rodent protection measures or are inadequate, which causes various accidents such as death from gas poisoning and gas explosion caused by rat rubbing the rubber pipes, resulting in great damage. Is brought. An example of a rodent-proof gas pipe using a mouse repellent, cycloheximide, has been reported for the purpose of preventing damage by such a mouse (Japanese Patent Laid-Open No. 47-22473).
issue).

[0003]

However, in the above method, cycloheximide has a low stability, and there are problems in the processing step and the sustaining effect. So, like this method,
When using a repellent agent to impart anti-mouse properties to a rubber tube for gas, it is necessary that the anti-mouse agent is stable during the processing process and the decrease in efficacy is minimized. Although tubes are required to maintain their rodent-proof effect for a long period of time, it is necessary to minimize the decomposition and disappearance of the active ingredient in the product. The rubber tube was unknown.

[0004]

As a result of various investigations to solve the above problems, the present inventors have found that capsaicins are used as active ingredients in rubber tube materials, preferably composite rubber tube type outer layer resins. The present inventors have completed the present invention by finding that such an object can be achieved by adding a microcapsule. The present invention will be described in detail below.

The capsaicins in the present invention are compounds represented by the formula 1 and may be used alone or in combination of two or more.

[0006]

[Chemical 1]

(Wherein R is an alkyl group having 7 to 12 carbon atoms,
Represents an alkynyl group or alkenyl group. ) More preferred R of the formula (1) has a carbon number of 7 to
Examples thereof include those of R of 10 but are not limited to these.

Those in which R is CH ₃ (CH ₂ ) ₆ (caprylic acid vanillyl amide), and R is CH ₃ (CH ₂ )
₇ - one (Noni Rick A Sid vanillylamide), R is CH ₃ (CH _{2) 8} - one (Desi Rick A Sid vanillylamide) of, R is _{(CH 3) 2 CH (CH} 2) 5 - ones (Nordihydrocapsaicin I), R is (CH ₃ ) ₂
CH (CH ₂ ) _6- (dihydrocapsaicin),
R is _{(CH 3) 2 CH (CH} 2) 7 - one (homo dihydrocapsaicin I), R is CH ₃ CH ₂ CH (C
H ₃ ) (CH ₂ ) ₄ − (nordihydrocapsaicin), R is CH ₃ CH ₂ CH (CH ₃ ) (CH ₂ ) ₆ −
(Homodihydrocapsaicin), R is (CH ₃ )
_{2 CHCH = CH (CH 2)} 4 - ones (capsaicin), R is _{(CH 3) 4CHCH 2 CH =} CH (C
H _{2) 4} - ones (homocapsaicin I), R is CH _{3
CH 2 CH (CH 3) CH} = CH (CH 2) 4 - one (homocapsaicin).

[0009] Capsaicins are known as a pungent component of capsicum, and this pungent taste stimulates the taste sensation of rats and exhibits repellent properties. Capsaicins have high heat resistance and little decomposition even in high temperature processing steps. By encapsulating the active ingredient in microcapsules, it is possible to reduce decomposition and disappearance in the processing step. Further, the active ingredient has a strong pungent stimulus, and when it is directly kneaded with the resin, strong irritancy becomes a problem during working, but this irritancy can be reduced by encapsulation with microcapsules. Furthermore, it was confirmed that when capsaicins were made into microcapsules, spiciness and irritancy were suppressed, and the effect of preventing bites on rats was suppressed without being suppressed, although it was easy to handle. It is speculated that this was because the capsule membrane was destroyed when the rats bit the target, and the high concentration of capsaicin inside the capsule stimulated the intense pungency, stimulating it. Even if the amount of the active ingredient to be kneaded into the outer layer resin is 0.01% by weight or more, it shows repellent effect as compared with the case where no rodent-proof treatment is carried out, but 0.1% by weight or more is preferable to expect practical effect. .
The upper limit is preferably 2% mainly because of economy.

In the microencapsulation of the microcapsules containing the capsaicins used in the present invention, the core substance is preferably liquid, and in this case,
Capsaicins may be liquefied by heating even if heated and liquefied. Interfacial polymerization method, in situ method, coacervation method, submerged curing coating method (orifice method), submerged drying method, spraying -Microcapsules having a wall film formed by a method such as a granulation method are preferable. Such solvents include ethers such as butyl ether and ethyl vinyl ether, aliphatic and aromatic hydrocarbons such as heptane and xylene, organic chlorine such as dichloromethane and trichloroethane, mineral oils such as machine oil, vegetable oils and phthalates. Examples thereof include, but are not limited to, solvents mainly used as plasticizers for resins such as low molecular weight epoxy compounds such as adipic acid ester, phosphoric acid ester, and maleic acid ester.

Examples of the capsule wall for microcapsulating the capsaicins include resins such as urea resin, melamine resin, urea / melamine mixed resin, phenol resin, polyamide, polyester, polyurea and polyurethane. Among these, the microcapsules using the melamine resin are characterized by high heat resistance and high resistance to organic solvents.

The microcapsule preparation usable in the present invention is usually a powder containing capsaicins in an amount of at least 1% (by weight), preferably 5-80% (by weight). Is a spray dryer,
Any method such as multi-stage warm air dryer, vacuum dryer, etc.,
There is no particular limitation. The weight ratio of the core substance to the membrane material in the microcapsules is usually 1: 0.01 to 1:10, preferably 1: 0.1 to 1: 2, but is not particularly limited to this range.

Further, the average particle size of the microcapsules can be varied as desired and is usually adjusted to 1 to 150 μm, but in order to further enhance the effect of preventing bites of animals, the particle size is set to 1 μm to 100 μm. 90% or more in the range,
Moreover, it is preferable to adjust the average particle size to 5 μm to 50 μm.

The gas rubber tube according to the present invention comprises an inner layer 1 and an adhesive layer (rubber) surrounding the inner layer 1, as shown in FIG.
2. Further, the outer layer resin 4 surrounds the adhesive layer 2 with the adhesive 3 interposed therebetween, but is not limited to this. Thus, preferably, in the present invention, the capsaicins are
It is added to the outer layer resin. The outer layer resin means any resin used for the outer layer of the rubber tube for gas, but typically, a polyvinyl chloride resin, a polyvinyl chloride thermoplastic elastomer, a polyurethane thermoplastic elastomer and the like can be mentioned. Among them, the polyvinyl chloride-based thermoplastic elastomer has well-balanced properties such as flame resistance, weather resistance, gas resistance, and bending resistance, which are necessary for a rubber tube for gas, and the molding temperature is relatively low. It is preferably used. In this case, the molding temperature is preferably 180 ° C. or lower, and if the temperature is higher than 180 ° C. and the heat is received for a long time, the destruction of the microcapsules increases. When an all-rubber multi-layer rubber tube is added to the outer rubber layer, the shearing force during mixing and the amount of heat received during vulcanization are both large compared to the resin, so the microcapsule residual rate decreases and rodent resistance decreases. .

Although the thickness of the outer layer resin is not particularly limited, it is preferably 0.2 mm or more in order to obtain a stable effect.

The outer layer resin which can be used in the present invention is a resin such as a polyvinyl chloride thermoplastic elastomer, a capsaicin-based microencapsulated murine repellent and, if necessary, a plasticizer such as dioctyl phthalate, a barium-zinc organic composite. Stabilizers such as, and pigments such as titanium oxide are mixed in an appropriate amount, and obtained by mixing these by a conventional method.The outer layer is molded by using a crosshead extruder and coated on the inner layer rubber by a conventional method. It

[0017]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the examples, a microencapsulated murine repellent containing 32% of a synthetic compound of capsaicin (trade name: R-731, manufactured by Nippon Kayaku Co., Ltd.) was used.

(Evaluation method) 1. Rat repellent effect of rubber tube for gas with rodent-proof treatment The rubber tube of Table 1 cut to a length of 20 cm was used as a sample, placed in a cage containing rats, left overnight and collected, and the degree of bite damage was observed.

[0019]

[Table 1]

2. Evaluation as a rubber tube for gas The items specified in JIS K 6348 (rubber tube for gas) were evaluated.

Example 1 The components shown in Table 2 are mixed by a conventional method to obtain a resin composition. Then, using a crosshead extruder, preforming,
The vulcanized inner layer rubber tube was coated to obtain a rat-proof rubber tube for gas according to the present invention. The evaluation test results of the rubber tube are shown in Tables 3 to 4, and the performance was good in all items.

Comparative Example 1 Comparative Example 1 was prepared under the same conditions as in Example 1 except that the components shown in Table 2 were used. These were also evaluated in the same manner as in Example 1. The results are also shown in Tables 3 and 4.

[0023]

[Table 2]

[0024]

[Table 3]

[0025]

[Table 4]

[0026]

Industrial Applicability As described above, the rubber tube according to the present invention is capable of ensuring a stable rodent-proof effect for a long time without deteriorating the characteristics of the rubber tube for gas. It can be suitably used as a tube.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of a rubber tube for gas that has been subjected to rodent-proof processing of the present invention.

[Explanation of symbols]

 1 Inner layer (rubber) 2 Adhesive layer (rubber) 3 Adhesive 4 Outer layer resin

Claims (2)

[Claims] 1. A rubber tube for gas, which is a rubber tube for gas, characterized in that a murine repellent obtained by microencapsulating capsaicin as an active ingredient is added to a rubber tube material. 2. The rubber tube for gas according to claim 1, wherein the amount of the active ingredient is 0.1 to 2.0% by weight.