Patent Application
20230149206
The present disclosure relates to the field of condom materials, and in particular, to a mold for molding a polyurethane condom, a method for manufacturing the mold, and a method for using the mold.
Condoms are simple devices widely used in the world for contraception and prevention of sexually transmitted diseases. The current condom products mainly include natural rubber latex condoms and polyurethane condoms.
In the dip molding process for a natural latex rubber condom, a mold made of glass or a metal material such as stainless steel is mainly used. Since the natural latex rubber material has a surface tension close to that of glass and stainless steel, the film formed from natural latex rubber on the surfaces of these two materials shows relatively weak adhesion. Furthermore, natural latex rubber has a swelling property in an alkaline environment. Therefore, natural latex rubber condoms are demolded by swelling in ammonia water after being molded on the surface of a glass mold or a metal mold.
However, a condom made of a polyurethane material does not have the swelling property of natural latex rubber, and has a surface tension of about 55 mN/m. A dried coating film thereof has a surface tension of about 45 mN/m. A polyurethane emulsion can be spread on molds of glass, ceramic, and stainless steel, and a dried waterborne polyurethane film has very strong adhesion to these molds, causing difficulty in rolling and demolding, preventing these two materials from being directly used for dip molding of polyurethane condoms. In order to solve the problem in molding of polyurethane, two methods are currently used in the world: (1) alkylating the glass surface to bring the surface tension of the glass close to that of a polyurethane material, whereby the problem with film formation and demolding of polyurethane materials on glass can be solved, but the time period available for effective use after alkylation is as short as about 30 h, not allowing continuous production; and the stability of quality of the polyurethane condom products cannot be effectively guaranteed in the production process because the effect of alkylation varies from time to time; and (2) Pre-coating the surface of glass or stainless steel with a layer of a release agent, whereby the problem with continuous production can be solved, but the release agent may be carried into the condom material during the production process, posing a potential risk to the performance and biosafety of the product.
Therefore, there is a need for further improvement and optimization of the mold for molding of polyurethane condoms, which also represents a research hotspot and difficulty in this field.
The present invention is made in view of the above-described drawbacks in the prior art. One of the objectives of the present disclosure is to provide a mold for molding a polyurethane condom, and the polyurethane condom is thin and has excellent flexibility and strength, satisfying the market demand for the product.
Another objective of the present disclosure is to provide a method for manufacturing the mold for molding a polyurethane condom.
Another objective of the present disclosure is to provide a method for using the mold for molding a polyurethane condom.
The present disclosure provides a mold for molding a polyurethane condom, which has a surface roughness of 0.2 or less, and is composed of a thermoplastic polymer having a surface tension of 10-35 mN/m.
In one embodiment, the thermoplastic polymer is any one selected from polyurethane, polymethyl methacrylate, polystyrene, polyethylene, polyvinyl chloride, polypropylene, polystyrene, acrylonitrile-butadiene-styrene, polyamide, polycarbonate, polyoxymethylene, modified polyphenylene oxide, thermoplastic polyester, polyimide, polyphenylene sulfide, polysulfones, aromatic polyamides, polyarylate, polyphenyl ester, polyaryletherketone, a liquid crystalline polymer, fluororesin, and materials obtained by organic modification of the above polymers or by inorganic modification by filling the above polymers with an inorganic material, or any combination thereof.
In an embodiment, the organic modification is any one selected from organosilicon modification, organofluorine modification, silane modification, acrylate copolymerization modification, vinyl monomer modification, and aromatic monomer modification, or any combination thereof.
In an embodiment, the inorganic modification is any one selected from heavy calcium modification, talc modification, graphene modification, water glass modification, attapulgite modification, kaolin modification, light calcium modification, and glass microbeads modification, and any combination thereof.
In one embodiment, the polyurethane condom is a male condom, and the mold comprising: a head portion, and a tail portion connected to the head portion, wherein the head portion has a columnar shape with a gradually increasing diameter, and has a slope greater than 0° and less than or equal to 5°.
In one embodiment, the head portion has a front end provided with a semen pouch.
In one embodiment, the head portion has a length of 200-260 mm.
In one embodiment, the head portion is connected to the tail portion via a transition section.
In one embodiment, the tail portion has a columnar shape with a constant diameter. In one embodiment, the tail portion has a columnar shape with a gradually increasing diameter, and has a slope greater than 0° and less than or equal to 3°.
In one embodiment, the polyurethane condom is a female condom.
In one embodiment, the polyurethane condom is a heterotypic condom, and the mold has a surface provided with floating points or screw threads.
In one embodiment, the mold has a thickness of 2-10 mm, or is a solid mold.
In one embodiment, when the mold is placed vertically, the mold has an angle less than 5° with respect to the vertical line.
The present disclosure also provides a method for manufacturing a mold for molding a polyurethane condom, comprising the steps of:
In one embodiment, the injection molding is carried out by three-shot feed and two-stage injection molding.
The present disclosure also provides a method for using a mold for molding a polyurethane condom, comprising the steps of:
In one embodiment, the polyurethane condom has a 100% tensile modulus of 2.5 N/mm2 or lower.
In one embodiment, the polyurethane condom has a burst pressure of 1 kPa or more, a burst volume of 5 L or more, and a 100% modulus of 3.5 N/mm2 or lower.
The polyurethane condom having an adhesive layer provided according to the present disclosure is prepared by using a mold for molding the polyurethane condom, wherein the mold is composed of a thermoplastic polymer having a surface tension of 10-35 mN/m, so that the polyurethane can uniformly form a film directly on the surface of the mold by dip molding. A film formed therefrom after drying has weak adhesion, allowing uniform demolding without the aid of a release agent, which ensures the uniformity of the polyurethane film and avoids introduction of other substances, thereby sufficiently ensuring the performance and biological safety of the polyurethane condom product. In addition, according to the mold provided in the present disclosure, the polyurethane material can be directly post-treated and shaped on the surface of the mold for raw material properties, without addition of other processes due to demolding, etc., which greatly simplifies the operation procedure, improves the production efficiency and increases the qualification rate of products. The raw materials for the mold of the present disclosure have a low cost and a rich source, and the molding process is simple, safe, and environmentally friendly. Other features, benefits, and advantages will be apparent from the disclosure detailed herein, including the description and claim.
The drawings used in the embodiments will be briefly described below to more clearly describe the technical solutions in the embodiments of the present disclosure. It is to be understood that the following drawings depict only certain embodiments of the invention and are therefore not to be considered limiting its scope. For a person of ordinary skill in the art, other relevant drawings can also be obtained according to these drawings without paying any inventive effort.
The technical solutions of the embodiments in the present disclosure will be clearly and fully described with reference to the accompanying drawings, in order to provide a clear understanding of for the objectives, technical solutions and advantages of the embodiments of the present disclosure. Obviously, it is to be understood that the described embodiments are part of, and not all of, the present disclosure. The components of the embodiments in the present disclosure, which are generally described and illustrated in the drawings herein, can be configured and designed upon different needs.
As shown in
The polyurethane condom 100 having a thickness within the above range has a burst pressure of for example 1 kPa or more, preferably 3 kPa or more, for example, 3 kPa, 4 kPa, or 5 kPa, and a burst volume of for example 5 L or more, for example, 6 L, 8 L, or 10 L.
The polyurethane condom 100 may have a strength, e.g. tensile strength, of for example 30 MPa or more, preferably 70 MPa or more, and a 100% modulus of for example 3.5 N/mm2 or lower, such as 2 N/mm2, 1.8 N/mm2, 1.5 N/mm2, or 1 N/mm2.
It is noteworthy that the emulsion comprising a polyurethane resin has a surface tension for example in a range of 20-80 mN/m, preferably in a range of 30-60 mN/m, such as 32 mN/m, 40 mN/m, 50 mN/m, 55 mN/m, and 58 mN/m. After being molded and dried on the surface of the mold 20 provided in the present disclosure, the polyurethane film has a surface tension in a range of 15-68 mN/m, such as 20 mN/m, 28 mN/m, 45 mN/m, or 50 mN/m. Within the above range, the emulsion containing the polyurethane resin may be uniformly spread on the mold 200, and the dried film has low adhesion, thereby ensuring uniform film formation and demolding.
In some embodiments, the emulsion comprising a polyurethane resin may form, for example, a layer from the emulsion of the polyurethane resin mixed with other auxiliary agents. The auxiliary agents may be, for example, functional auxiliary agents such as a lubricant, a bactericide, a thickener, a wetting agent, an antifoaming agent, water, and the like, but not limited thereto. The polyurethane resin may be any suitable kind of aliphatic polyurethane or aromatic polyurethane, and may be preferably, for example, an anionic, cationic, nonionic, amphoteric, solvent-based or solvent-free polyurethane. The raw materials and preparation process for the polyurethane may be adjusted to prepare a desired polyurethane. Furthermore, from the viewpoint of obtaining excellent film-forming and demolding properties, the polyurethane resin may be selected from, for example, a polyurethane resin synthesized from polyether/polyester polyols, may have a 100% tensile modulus of 3.5 N/mm2 or lower, and a tensile strength of 25 MPa or more, for example. The present invention is certainly not limited thereto.
As shown in
The mold 200 is composed of a thermoplastic polymer having a surface tension in a range of 10-35 mN/m, for example, 25-35 mN/m, such as 35 mN/m, 32 mN/m, 30 mN/m, or 28 mN/m. When the surface tension of the thermoplastic polymer is less than 10 mN/m, it is difficult to spread the polyurethane emulsion uniformly on the mold 200 composed of the thermoplastic polymer; and when the surface tension of the thermoplastic polymer is more than 35 mN/m, the adhesion between a dried film formed from the polyurethane emulsion and the mold 200 composed of the thermoplastic polymer is too strong to allow smooth demolding. Within the above range, when the polyurethane emulsion is molded, for example, dip-molded, on the mold 200, the polyurethane emulsion can uniformly form a film directly on the surface of the mold, and a film formed after drying has low adhesion to allow uniform demolding without the aid of a release agent, which ensures uniformity of the polyurethane film and avoids introduction of other substances, thereby sufficiently ensuring the performance and biological safety of the polyurethane condom product.
In some embodiments, the thermoplastic polymer material may be, for example, ethylene-based polymers, propylene-based polymers, diene-based polymers, aromatic polymers, and polyurethanes, polycarbonates, polymethyl methacrylates, polyamides, thermoplastic polyesters, polyoxymethylenes, and halogenated thermoplastic polymers, such as thermoplastic polyesters.
In some embodiments, the ethylene-based polymer may specifically be polyethylene and copolymers thereof, ethylene-butene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, ethylene-propylene-butene copolymers, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl methacrylate copolymers, chlorinated polyethylene, ethylene-vinyl alcohol copolymers, or the like.
The propylene-based polymer may be polypropylene, polyacrylonitrile, propylene-ethylene copolymers, propylene-butene copolymers, propylene-hexene copolymers, propylene-octene copolymers, or the like.
The diene-based polymer may be polybutadiene, polyisoprene, butadiene-styrene copolymers, butadiene-acrylonitrile copolymers, ethylene-propylene-5-ethylene-2-norbornene copolymers, ethylene-propylene-dicyclopentadiene copolymers, or ethylene-propylene-5-vinyl-2-norbornene copolymers.
The aromatic polymers may be polystyrene, modified polyphenylene ether, or copolymers thereof, such as styrene-acrylonitrile copolymers, styrene-acrylonitrile-butadiene copolymers, acrylic rubber-acrylonitrile-styrene copolymers, or acrylonitrile-chlorinated polyethylene-styrene copolymers.
The above mentioned materials may be further selected from, for example, waterborne polyurethane, polymethyl methacrylate, polystyrene, polyethylene, polyvinyl chloride, polypropylene, polystyrene, butadiene-styrene, polyamide (e.g. polyamide 6, polyamide 11, polyamide 12, polyamide 6.6, polyamide 4.6, polyamide 6.10, and polyamide 6.12, etc.), polycarbonate, polyoxymethylene, modified polyphenylene oxide, thermoplastic polyester, polyimide, polyphenylene sulfide, polysulfones, aromatic polyamides, polyarylate, polyphenyl ester, polyaryletherketone, a liquid crystal polymer, and fluororesin.
In other embodiments, the thermoplastic polymer may also include materials obtained by organic modification of the above polymers or obtained by inorganic modification by filling the above polymers with an inorganic material. Furthermore, the modification may be chemical or physical modification, or in any other suitable manner.
The organic modification may be for example organosilicon modification, organofluorine modification, graphene modification, silane modification, acrylate copolymerization modification, vinyl monomer modification, aromatic monomer modification and the like, but not limited thereto.
The inorganic modification may be for example heavy calcium modification, talc modification, graphene modification, water glass modification, attapulgite modification, kaolin modification, light calcium modification, glass microbeads modification and the like.
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The mold 200 may be obtained, for example, by using an injection molding machine. A multi-shot feed, such as a three-shot feed, may be employed to ensure uniform feeding of the thermoplastic polymer in the injection molding machine. Furthermore, the mold 200 may be obtained by two-stage molding, in which the head portion 210 and the tail portion 220 are separately formed and then assembled to form the mold 200, but not limited thereto. The head portion 210 and the tail portion 220 may also be integrally molded.
When the mold 200 is used to mold a polyurethane condom, the mold 200 is hung vertically, dipped in an emulsion of waterborne polyurethane, and then taken out to allow the polyurethane to form a film on its surface, followed by demolding. The polyurethane film can be demolded smoothly without a release agent, and does not adhere to the mold 200.
In a particular embodiment of the present disclosure, the mold 200 can be manufactured by a method comprising three-shot feeding through the open end of the tail portion 210 and two-stage injection molding, wherein polyethylene (Enable™ performance polyethylene from ExxonMobil Chemical) is formed into a cylindrical tubular body for the mold by injection molding. The head portion 210 has a length H1 of 220 mm, and a slope of 0.2° from the front end to the rear end, such that the diameter of the front end of the head portion 210 is smaller than the diameter of the rear end thereof and of the tail portion. The tail portion 220 has a length H2 which is not limited. The mold 200 has a wall thickness of 2 mm, a surface roughness (Ra) of 0.2 or less, and a verticality, the angle between the vertically placed mold and the vertical line, less than 5°.
In another particular embodiment of the present disclosure, the mold 200 can be manufactured by a method comprising three-shot feeding through the open end of the tail portion 210 and two-stage injection molding, wherein polypropylene (TB54I from Hanwha-Total) is formed into a cylindrical tubular body for the mold by injection molding. The head portion 210 has a length H1 of 230 mm, and a slope of 3° from the front end to the rear end, such that the diameter of the front end of the head portion 210 is smaller than the diameter of the rear end thereof and of the tail portion. The tail portion 220 has a length H2 which is not limited. The mold 200 has a wall thickness of 5 mm, a surface roughness (Ra) of 0.2 or less, and a verticality, the angle between the vertically placed mold 200 and the vertical line, less than 5°.
In another particular embodiment of the present disclosure, the mold 200 can be manufactured by a method comprising three-shot feeding through the open end of the tail portion 210 and two-stage injection molding, wherein polycarbonate (Bayer 2407) is formed into a cylindrical tubular body for the mold by injection molding. The head portion 210 has a length H1 of 240 mm, and a slope of 5° from the front end to the rear end, such that the diameter of the front end of the head portion 210 is smaller than the diameter of the rear end thereof and of the tail portion. The tail portion 220 has a length H2 which is not limited. The mold 200 has a wall thickness of 10 mm, a surface roughness (Ra) of 0.2 or less, and a verticality, the angle between the vertically placed mold 200 and the vertical line, less than 5°.
The above description is merely preferred embodiments of the present disclosure, and is not intended to limit the present disclosure. For a person skilled in the art, the features in the above-described embodiments can be combined with each other as long as there is no conflict, and the present disclosure can also have various modifications and changes. Any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the present disclosure are intended to be included within the scope of the present disclosure. Furthermore, the examples are to be construed as illustrative and not restrictive, while the scope of the present disclosure is defined by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are therefore intended to be included herein. Any reference number used in a claim should not be construed as limiting the claim.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202010242233.8 | Mar 2020 | CN | national |
| 202010430499.5 | May 2020 | CN | national |
| 202010431395.6 | May 2020 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/096323 | 6/16/2020 | WO |
