JPH0632095Y2 - condom - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a condom.

(Prior Art) A conventional condom is formed by the sulfur method using a vulcanization accelerating aid for metal oxides such as sulfur and zinc oxide.

(Problems to be solved by the invention) However, according to the above-mentioned conventional technique, since sulfur and zinc oxide which are powders are used, pinholes are easily generated, and vulcanization proceeds even after molding. As the vulcanization progresses and the quality may change over time, such as deterioration of quality, not only the wearability and the feeling of wearing may deteriorate, but also the condom may cause small cracks due to change over time. There was plenty of room for improvement.

The present invention has been made in view of the above problems of the above-mentioned prior art, and the purpose thereof is to reliably suppress the occurrence of pinholes, to provide more flexibility, and to improve the aging after molding. It is to prevent change and maintain constant quality for a long time.

(Means for Solving the Problems) The technical means of the present invention to achieve the above object is to add a latex solution to which n-butyl acrylate is added,
That is, it is formed by using a main raw material that is formed by irradiating ionizing radiation.

(Function) When the rubber is cross-linked by ionizing radiation without adding a vulcanization accelerator for metal oxides such as sulfur and zinc oxide by the above-mentioned technical means, pinholes are less likely to be generated, and the post-molding addition is difficult. Sulfur does not proceed, does not change with time, and has a low modulus and becomes soft.

In addition, n-butyl acrylate accelerates the crosslinking rate, no rubber solvent is used together, and there is no residual monomer.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings.

The illustrated condom (A) has a conventionally well-known form, and contains rubber latex as a main component, and a radiation crosslinking agent that crosslinks by ionizing radiation is added thereto to form a latex solution. The main raw material is constituted by irradiating with radiation, a condom molding die (not shown) is dipped in the main raw material to form a thin film, and then dried.

As the rubber latex, use natural rubber latex or synthetic rubber latex whose main component is polyisoprene,
These latices are used alone or in an appropriate combination.

Additives such as a plasticizer, a stabilizer, an antiaging agent, a filler, a reinforcing agent, a viscosity imparting agent, and a pigment are added to the rubber latex in an appropriate ratio, if necessary.

The radioactive cross-linking agent has an action as a cross-linking accelerator that accelerates the cross-linking speed when cross-linking the rubber component of the rubber latex by ionizing radiation as described above, and reduces the irradiation dose of the above-mentioned radiation, One C = in one molecule
Acrylic acid n-, which is a monofunctional monomer having a C bond
Limited to butyl.

Then, a latex solution is formed by adding the radiation crosslinking agent to the liquid containing rubber latex as the main component.

That is, in a polyfunctional monomer system that also uses a rubber solvent,
Since the solvent is absorbed by polyisoprene, there is a risk that pinholes may be formed on the rubber surface during drying, and even with a monofunctional monomer that has an alkyl group with a smaller molecular weight than the butyl group, rubber latex It is not practical because it has poor reactivity to.

Thus, when n-butyl acrylate is used,
Residual monomer that swells rubber and deteriorates its physical properties is not detected, and the occurrence of pinholes, which are fatal to a condom with a very thin wall, is significantly reduced. In addition, with monofunctional monomers that have an alkyl group with a higher molecular weight than the butyl group, the residual monomer is 200 to 1
Approximately 000 ppm remains, which may cause a problem of toxicity that causes skin irritation.

The rubber latex is added in an amount of 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the rubber content.

As the anti-aging agent, those usually used in this technical field are used.

The amount of antioxidant added is 0.5 to 100 parts by weight of rubber.
A ratio of about 2.0 parts by weight is suitable.

If this antioxidant is added before the irradiation of ionizing radiation, it is decomposed by γ-rays and loses its effect, so that it is added after the above irradiation.

Ionizing radiation includes α-rays, β-rays, γ-rays, x-rays, electron rays, etc. Among them, γ-rays, electron rays and x-rays are industrially more practical.

The radionuclide nuclide used as the source of this radiation is not limited, but Co60 is industrially practical.

The irradiation dose of ionizing radiation does not need to be particularly limited, but is 0.
A range of 5-10 Mrad is practical, and 1.0-8 Mrad is more preferable.

The condom (A) of the present invention is formed from the main raw material constituted by irradiating the latex solution with the above-mentioned ionizing radiation.

The latex solution may optionally contain additives such as plasticizers, stabilizers, antioxidants, fillers, reinforcing agents, viscosity imparting agents, pigments, etc., which are usually used in the art, as required in the prior art. It is possible to mix them in various proportions.

Here, the outline of the process of molding the condom (A) of the present invention by the dip molding method and an example of the conditions are as follows: condom molding die → latex liquid (main raw material) dipping → drying (80 ° C, 10 minutes) → Mouth roll → Main drying (80 ° C, 20 minutes) → Peeling of molded product → Extraction with dilute alkaline solution (ammonium hydroxide, sodium hydroxide, potassium hydroxide, etc.) → Adhesion prevention treatment → Drying (80 ° C, 60 minutes) Therefore, except for the constitution of the latex liquid (main raw material) and the drying conditions of the main drying which are the features of the present invention, it is completely the same as the case of the conventional sulfur method.

The composition of the main raw material in the present invention is that sulfur, which has been conventionally used in the sulfur method, and metal oxides such as zinc oxide as a vulcanization accelerator are not added, and that radiation crosslinking that acts by ionizing radiation causes crosslinking. It is characterized in that the agent is added and pre-crosslinked by the above-mentioned radiation, and in the case of the sulfur method, the drying conditions for the main drying in the above step are 60 minutes at 80 ° C. because the vulcanization step is included. However, the present invention has the advantage that 20 minutes is sufficient.

Further, in the case of the radiation crosslinking method, there is an advantage that pinholes are extremely reduced because powdery sulfur and zinc oxide are not used.

In addition, when the condom is incinerated at the time of disposal, the present invention remarkably reduces generation of various harmful gases as compared with the conventional sulfur method.

That is, since sulfur used as a vulcanizing agent in the sulfur method is not mixed, there is little generation of SO _{X that} causes pollution such as air pollution and acid rain, corrosion of incinerators, etc. In this case, the organic nitrogen compounds such as proteins present in natural rubber generate NO _X , hydrogen cyanide, carbon monoxide, etc. which cause photochemical smog.
In the case of the present invention, since the organic nitrogen compound is decomposed by the irradiation of ionizing radiation, most of the gas is extracted by extraction with a dilute alkaline solution in the condom (A) forming step described above. The occurrence is significantly reduced (see test results in Table A).

In the sulfur method, metal oxides such as zinc oxide used as a vulcanization accelerator do not burn even when incinerated, so the entire amount remains as ash, that is, waste, and the ceramic filter in the incinerator is clogged. However, in the case of the present invention, since this metal oxide is not contained, the amount of ash after incineration, that is, the amount of waste can be reduced (see the test results in Table A), and the ceramic filter as described above can be used. It is possible to prevent clogging.

Furthermore, the condom (A) molded according to the present invention is
Because of its low modulus and flexibility, it has better wearability and fit compared to the sulfur method (see test results in Table B), and since it does not use a dithiocarbamate system as a vulcanizing agent. No worries about a rash. .

Next, an example of a specific method for molding the condom (A) of the present invention will be described.

The main raw materials are compounded as follows: (a) 100 parts by weight of natural rubber latex (rubber content) (b) 5 parts by weight of n-butyl acrylate (c) 2,2'-methylenebis (4-methyl-6-t-)
Butylphenol) 1.0 part by weight, but first add (b) to (a) and add 1
A latex solution is prepared by stirring for a period of time, and this latex solution is irradiated with 5 Mrad γ-rays using Co60. Then, (c) is added.

Using the main raw material configured as described above, molding is performed according to the molding process of the above-mentioned dip molding method to obtain a condom (A) as illustrated.

Table A shows measurement results of various harmful gases and ash content when the condom (A) thus formed is incinerated.
In addition, the measurement results of the physical property test (500% modulus) are shown in Table B in comparison with the conventional sulfur method (see the above description touching both measurement results).

(Effects of the Invention) Since the present invention has the configuration as described above, it has the following effects.

Since it was formed by cross-linking with ionizing radiation without adding a vulcanization accelerating aid for metal oxides such as sulfur and zinc oxide, pinholes are suppressed from occurring, and vulcanization proceeds after molding as before. Since there is no fear that the rubber will change over time, it is possible to maintain a certain quality for a long period of time, that is, there is no risk of fine cracks in the condom due to change over time. Therefore, contraception can be reliably performed, and it can be offered as a very useful and highly reliable product.

Further, although not particularly for condoms, there are latex compositions which are generally crosslinked by radiation crosslinking by adding a polyfunctional monomer as described in JP-A-57-153034. The rubber solvent is also used, and it causes pinholes because the solvent flies with the passage of time. However, the present invention uses n-butyl acrylate, which has no residual monomer among the monofunctional monomers. Since it is used, there is no worry of toxicity such as skin irritation.

Further, since the modulus is low and soft, the wearability at the time of wearing and the feeling of wearing after wearing can be improved.

In addition, in the case of the conventional sulfur method for incineration at the time of disposal, a large amount of harmful gases such as sulfur oxides (SO _X ), nitrogen oxides (NO _X ), hydrogen cyanide and carbon monoxide, which cause pollution, are generated. Since it was not possible to incinerate because of this, since the generation of these harmful gases is significantly reduced, it is possible to incinerate and it is hygienic, and since it does not contain metal oxides such as zinc oxide, The amount of ash as waste is reduced, and clogging of the ceramic filter in the incinerator can be eliminated.

In addition, since there is no need for heat vulcanization in a conventional film state, the cost is reduced and it is very useful.

[Brief description of drawings]

1 is a plan view showing an embodiment of a condom constructed according to the present invention. In the figure A: Condom

Claims (1)

[Scope of utility model registration request] 1. A condom formed from a main raw material which is formed by irradiating a latex solution containing n-butyl acrylate with ionizing radiation.