MXPA05011805A - Process for manufacturing flexible solid monolithic inner tubes hermetically closed useful for tyres, and products obtained therewith. - Google Patents

Abstract

The invention relates to a method of producing solid semi-flexible monolithic inner tubes hermetically closed for tyres which are made from polyurethane elastomer material and which are characterised in that they can recover the original shape thereof, with the self-sealing of punctures, and to inner tubes thus obtained. The inventive method comprises the following steps consisting in: 1) heating a polymer resin having a viscosity varying between 1000 and 25000 centipoises to a temperature varying between 25 and 120 DEG C; 2) placing the hot resin in a vacuum chamber with a vacuum of between 1 and 32 inches of mercury for between 5 and 390 minutes; 3) mixing the hot resin with another mixture of isocyanate- and amine-type catalysts at a concentration of between 10 and 80 wt.- % of any mixture selected from said type of catalysts for between 5 and 20 minutes at a velocity of between 60 and 6500 revolutions per minute; 4) producing the inner tube in two separate parts which are subseque ntly joined, by emptying the mixture, which occupies 10 to 50% of the mould volume, into two moulds which have been prepared with a mould release agent and which have been pre-heated to a temperature of between 20 and 130 DEG C, each mould being made from a metal material or different suitable resins for manufacturing moulds useful for pouring plastic resins; the mould is placed into a mould carrier pertaining to a roto-moulding machine which has two different spins rotating in a perpendicular direction with respect to each other, each spin being performed at a speed of 10 to 200 revolutions per minute for about 15 to 90 minutes, the resin being adjusted at a temperature of 20 to 130 DEG C; 5) producing the inner tube in a single part by pouring an amount of mixture occupying from about 10 to 50% of the tyre inner volume into the pre-heated at a temperature of 20 to 130 DEG C, the side aperture of the tyre inner circle being closed with a cap made of any metallic material, wood or any plastic resin, then placing the tyre into the mould carrier of a roto-moulding machine which has two different spins rotating in a perpendicular direction with respect to each other, each spin being performed at a speed of 10 to 200 revolutions per minute for about 15 to 90 minutes, the resin being adjusted at a temperature of 20 to 130 DEG C; 6) leaving the part to cure at ambient temperature or heating same to a maximum temperature of 120 DEG C for a period of 6 to 24 hours; 7) following said period, stripping the part and leaving same to rest for 24 hours; 8) attaching an air valve to the inner tube by means of a pipe or a hose. 9) inserting the inner tube into a normal vehicle tyre and, subsequently, inserting the tyre into the rim of the vehicle and filling same with pressurised air in accordance with that specified for the tyre of the vehicle. The tyre inner tubes thus produced have the following properties: any section of the inner tubes can be repeatedly extended or compresse d, such as to return to the original shape and dimensions thereof, with the self-sealing of perforations caused by impacts from bullets, sharp metal parts or sharp rigid parts, thereby preventing air from being released from the tyre and enabling the continued use of said tyre.

Description

PROCEDURE TO MANUFACTURE FLEXIBLE SOLID CASES, OF A SINGLE PIECE CLOSED HERMETIC HOLES FOR TIRES, AND RESULTING PRODUCTS.

FIELD OF THE I NVENTION The present invention relates to a novel rotational molding process using liquid polyurethane resins to make tire protectors and, more particularly, to a rotomoulding process of liquid resin for the manufacture of a solid, semi-flexible, fully enclosed, hollow, hermetic shell. for a rim, made of polyurethane elastomeric material, which when perforated either by bullet impact, sharp or sharp parts, etc. , has the peculiarity of self-sealing said perforations, thus preventing the release of air and allowing its filtration to continue.

BACKGROUND OF THE INVENTION Various types of processes are known for the manufacture of chambers, covers and rims for vehicles, whose chambers, covers and rims are manufactured by processes other than the rotomolding of liquid resin, with materials of different chemical formulations, which do not have the peculiarity of being a semi-flexible solid that self-punches the punctures caused by bullets or sharp objects.

Likewise, there are pasty flowing compounds, not rigid or liquid, that are encapsulated between two layers that are inside a rim, being a different process to the rotomolding of liquid resin, these pasty compounds are of different physical structures and have different chemical formulations, providing another type of sealing mechanism. Examples of these pasty compounds are those of Mexican patent 183,487 entitled "Sealant formulation of Perforations"; US Patent Application 9022001992/06/22 in which high molecular weight low molecular weight liquid elastomer polymers and a crosslinking agent are claimed; European application 01917627 entitled "Anti-perforation sealing agent, tires without air chamber and pneumatic air chamber"; Chinese Patents 1350493, 1350494 and 1425051; American application series 10 / 239,872; US Patent 6,868,881 B1; European Patents 1 18058A1, 1065042A1, 0816, 132A, 1281 741 A1; and European application 99901959 entitled "Procedure for manufacturing tires with sealing agents and tires with oil sealing", etc. Summing up in these patents and applications encapsulated sealants are claimed that cover only the bottom of the rim, that is, viscous pastes that flow in the holes, sealing the punctures of a rim by another different mechanism. There are sealants of punctures that are some emulsions of mixtures of liquids and solids of chemical formulation and different physical structures, with manufacturing process different from rotomolding of liquid resin, such as those of the North American patent applications 200300674 and European 00948709 and 991 18293; application P2000302719, patent LP 10017051; Japanese patents 2000104042, 57063374, 54008307, 2003193030; U.S. Patent Nos. 5,705,604, 5,124,395, 6,063,837, 6,283, 1 72B 1, 5,856,376 and 6,454,892; U.S. Patent Application 2004 / 0048962A1 European Patent 1270188A1; international applications PCT / US92 / 00405, PCT / US00 / 19401, PCT / EP98 / 05807; British Patent 2370574; Japanese patent 2001301050, French patents 2735486 and 2727978; and applications PCT / US01 / 19548 and PCT / AU95 / 00487 etc. These patents and applications claim emulsions of mixtures of solids and liquids that are placed inside the tire, which serve to fill the punctures of the tire by a mechanism of sealed different. Other puncture sealers are sticky materials that do not flow, have a different physical structure and chemical compositions that are made by a process other than rotomolding of liquid resin, such as those of European application 90001 124, Chinese patents 1569501, North American 6864.305B2; European 1291 156 and 0867494A2, etc. In these patents and applications, sticky coatings are described that do not flow in the inner layer of the tire, to seal punctures of the tire by another different mechanism. Still more other sealants are made from solid powder mixtures having different chemical compositions and physical structures and are made by a process other than liquid resin rotomolding, such as those of the US 6,506,730B1 and Taiwanese 472004 patents, which describe mixtures of powders that are placed inside the tire sealing the punctures by a different mechanism. There are sealants that are manufactured with a process different from the rotomolding of liquid resin, which consist of layers of mixtures of butyl rubber, isoprene and different varieties of rubber of different chemical composition and physical structure, for sealing punctures in tires by a mechanism different; such as those of the North American patents 2004/0159386 and 2003/3230376 and European 1457308A1. There are chambers that are manufactured with an elastomeric material of similar composition by a traditional molding process completely different to the rotomolding of liquid resins and whose shape resulting from the traditional molding does not turn out to be a completely closed and hermetic piece; such as that of the Mexican patent application PA / a / 2005/010181. OBJECTIVES OF THE INVENTION An object of this invention is to provide a novel rotomoulding process of liquid resins for making flexible, one-piece, flexible, hollow-sealed, flexible tires, for tires, of polyurethane elastomeric material or the like, which when perforated by bullet impact , metal sharp pieces, such as screws, nails, etc., and sharp pieces such as glass, sharp points, etc. , have the peculiarity of self-sealing. Another objective is to provide a process for making solid, one-piece flexible closed hollow shells that cover the entire interior of the tires. Still another object is to provide a process for manufacturing flexible, one-piece, flexible, hollow-sealed, solid tires for tires, which is simple, easy to carry out, and of minimum duration of time and cost. DESCRIPTION A process for the manufacture of a flexible solid one-piece hollow closed hermetic tire sleeve is described, said sheath is made by a rotomolding process of liquid resin to form a polyurethane elastomer that has the peculiarity of self-sealing perforations. Said cover is inserted inside the normal rim of a vehicle, to avoid leakage of air caused by punctures allowing the filming to continue. This procedure consists of the following steps: 1) heating a polymeric resin which is a mixture of the type used for the manufacture of flexible polyurethane elastomers, with an appropriate viscosity and temperature; 2) place the hot resin in a desired vacuum chamber; 3) mixing the hot resin with another mixture of isocyanate and amine type catalysts, in a specific amount of any selected mixture of catalysts of this type, for a determined time at a desired speed; 4) to manufacture the semi-flexible, solid, one-piece, hermetically sealed hollow sleeve in a mold of two separate pieces that will be subsequently joined, emptying an appropriate amount of the mixture into the previously prepared mold with a release agent and preheating to a specific temperature, the mold is made of any type of metal material or various resins suitable for the manufacture of molds for emptying plastic resins, close and place the mold in the mold holder of a rotomolding machine that has two different turns in the perpendicular direction one with respect to the other and each turn with a specified speed and time adjusting a suitable temperature for the resin; 5) to manufacture the solid, semi-flexible, one-piece, hermetically sealed hollow sleeve inside the rim without using a mold, emptying within the preheated rim at a specific temperature an appropriate amount of the mixture, closing the lateral opening of the inner circle of the rim with a lid made of any metallic material, wood or various plastic resins, place this rim in the mold holder of a rotomoulding machine that has two turns in a perpendicular direction with respect to each other with a specified speed and time setting a suitable temperature for the resin; 6) allow the piece to cure at room temperature or by heating to a maximum temperature, for a desired period; 7) After this period, unmold the piece and let it rest for an appropriate period; 8) attach a valve for air to the sheath by means of a tube or hose assembled in the valve and sheath; 9) Insert the semi-flexible, solid, one-piece, hermetically sealed hollow sleeve inside a normal vehicle tire, then insert the tire into the vehicle's wheel and fill it with pressurized air, as specified on the vehicle's rim .

PREFERRED MODALI DADES OF THE I NVENTION In these embodiments, a method is described for making one-piece solid watertight closed shells for tires, made of elastomeric polyurethane material, and chambers obtained by said process. The process for manufacturing said semi-flexible closed one-piece sheath solid shells for rims of elastomeric material having the peculiarity of self-sealing punctures, in this embodiment is constituted by the steps of: 1) heating a polymer resin which is a mixture of the type which is used for the manufacture of flexible polyurethane elastomers, with a viscosity ranging from 1000 to 25,000 centipoise, and at a temperature ranging from 25 to 120 ° C. degrees Celsius; 2) place the hot resin in a vacuum chamber, with a vacuum ranging from 1 to 32 inches of mercury, for a time ranging from 5 to 390 minutes; 3) mixing the hot resin with another mixture of catalysts of the socianato and amine type, in an amount of 10 to 80% by weight of any selected mixture of catalysts of this type, for 5 to 20 minutes, at a rate of 60 at 6500 revolutions per minute; 4) to manufacture the semi-flexible, solid, one-piece, hermetically sealed hollow sheath in a mold of two separate pieces that will be joined later, empty a quantity of mixture that occupies 10 to 50% of the volume of the previously prepared mold with a mold release agent and pre-heated at a temperature of 20 to 130 degrees Celsius, the mold is made of any type of metal material or various resins suitable for the manufacture of molds for the emptying of plastic resins, placing the mold in the mold holder of a rotomolding machine that has two different turns in a perpendicular direction with respect to each other and each turn with a speed of 10 to 200 revolutions per minute for a time of 15 to 90 minutes and adjusting the resin to a temperature of 20 to 130 degrees centigrade; 5) to manufacture the semi-flexible solid one-piece closed hollow tight sleeve inside the rim without using a mold, emptying within the preheated rim at a temperature of 20 to 130 degrees centigrade an amount of mixture that occupies 10 to 50% of the inner volume of the rim, closing the lateral opening of the inner circle of the rim with a cover made of any metallic material, wood or various plastic resins, place this rim in the mold holder of a rotomolding machine that has two turns in a perpendicular direction one with respect to another with a speed of 10 to 200 revolutions per minute for a time of 15 to 90 minutes by adjusting the temperature of the resin from 20 to 130 degrees centigrade; 6) let the piece cure at room temperature or heating up to a maximum of 120 degrees centigrade, for a period of 6 to 24 hours; 7) After this period, unmold the piece and let it rest for a period of 24 hours; 8) attach a valve for air to the sheath by means of a tube or hose assembled in the valve and sheath; 9) Insert the semi-flexible, solid, one-piece, hermetically sealed hollow sleeve inside a normal vehicle tire, then insert the tire into the vehicle's wheel and fill it with pressurized air, as specified on the vehicle's rim . With this procedure, semi-flexible solid one-piece closed hermetically sealed tires for tires are obtained, made of polyurethane elastomeric material, with the following properties: any section of the covers can be extended or compressed repeatedly, returning to its shape and size original, self-sealing perforations caused by bullet impacts, metal sharp pieces and sharp pieces of rigid materials, preventing air from escaping from inside said rim, and allowing the running of these tires to continue. In other words, these cases have the peculiarity of self-sealing punctures caused by sharp or sharp objects in said cameras. It will be apparent to those skilled in the art that modifications may be made to this invention, without deviating from or departing from the scope of the following claims:

Claims (9)

R E I V I N D I C A C I O N S

1 .- Procedure for the manufacture of a semi-flexible solid one-piece closed hollow tight cover for a rim, which is made of elastomeric polyurethane material, where any section of the chamber can be extended or compressed repeatedly returning to its original shape and measurements, self-sealing perforations in it caused by bullet impacts, metal sharp pieces and sharp pieces of rigid materials, preventing air from escaping from inside said rim; the process being characterized by the following steps: 1) heating the polymer resin, which is a mixture of the type used for the manufacture of flexible polyurethane elastomers, and having a viscosity ranging from 1000 to 25,000 centipoise, at a temperature which varies from 25 to 120 ° C; 2) placing the hot polymeric resin in a vacuum chamber, which has a vacuum ranging from 1 to 32 inches of mercury, for a time ranging from 5 to 390 minutes; 3) Mix the hot polymer resin with another mixture of isocyanate and amine type catalysts, in an amount of 10 to 80% by weight of any selected mixture of catalysts of this type, for a period of 5 to 20 minutes, at a speed of 60 to 6500 revolutions per minute; 4) to manufacture the semi-flexible, solid, one-piece, hermetically sealed hollow sheath in a mold of two separate pieces that will later be joined, emptying a quantity of mixture that occupies 10 to 50% of the volume of the previously prepared mold with a release agent and preheated at a temperature of 20 to 130 degrees Celsius, the mold is made of any type of metal material or various resins suitable for the manufacture of molds for the emptying of plastic resins, placing the mold in the mold holder of a rotomolding machine that has two different turns in the perpendicular direction one with respect to the other and each turn with a speed of 10 to 200 revolutions per minute for a time of 1 5 to 90 minutes and adjusting the resin at a temperature of 20 to 130 degrees centigrade; 5) to manufacture the semi-flexible solid one-piece closed hollow tight sleeve inside the rim without using a mold, emptying within the pre-heated rim at a temperature of 20 to 130 degrees centigrade an amount of mixture that occupies 10 to 50% of the inner volume of the rim, closing the lateral opening of the inner circle of the rim with a cover made of any metallic material, wood or various plastic resins, place this rim in the mold holder of a rotomolding machine that has two turns in a perpendicular direction one with respect to the other with a speed of 10 to 200 revolutions per minute for a time of 15 to 90 minutes adjusting the temperature of the resin from 20 to 130 degrees centigrade; 6) allow the piece to cure at room temperature or heating up to a maximum temperature of 120 ° C, for a period of 6 to 24 hours; 7) After this period, unmold the piece and let it rest for a period of 24 hours; 8) attach a valve for air to the sheath by means of a tube or hose assembled in the valve and sheath; and 9) insert the camera inside a normal vehicle tire, then insert the tire into the vehicle's wheel and fill it with pressurized air, as specified on the vehicle's rim;

2.- The procedure in accordance with the claim 1, characterized in that the polymeric resin is a mixture of the type of resins used in the manufacture of flexible polyurethane elastomers, with a viscosity ranging from 100 to 25,000 centipoise.

3. The process according to claim 1, characterized in that the resin is heated to a temperature ranging from 25 to 120 ° C. A.- The procedure in accordance with the claim 1, characterized in that the resin is placed in a vacuum chamber having a vacuum ranging from 1 to 32 inches of mercury, during a time that varies from 5 to 390 minutes. 5. The process according to claim 1, characterized in that the isocyanate is any of the isocyanates used in the manufacture of flexible polyurethane elastomers. 6. The process according to claim 1, characterized in that the amine is of the type of amines used in the manufacture of flexible polyurethane elastomers. The process according to claim 1, characterized in that the resin mixture and the catalyst mixture are stirred for a period of 5 to 20 minutes, at a speed of 60 to 6500 revolutions per minute. 8. The method according to claim 1, characterized in that in order to manufacture the semiflexible solid one-piece closed hermetically sealed sleeve in a mold of two separate pieces that will be subsequently joined, a quantity of mixture occupying 10 cm is emptied. to 50% of the volume of the mold previously prepared with a release agent. 9. The procedure according to the claim 1, characterized in that the mold is preheated to a temperature of 20 to 130 degrees centigrade, the mold is made of any type of metallic material or of various resins suitable for the manufacture of molds for the emptying of plastic resins. 10.- The procedure of compliance don the claim 1, characterized in that the mold is placed in the mold holder of a rotomolding machine having two different turns in a perpendicular direction with respect to each other and each rotation with a speed of 10 to 200 revolutions per minute for a time of 15 to 90 minutes 1 .- The method according to claim 1, characterized in that the temperature of the resin inside the mold is adjusted from 20 to 130 degrees centigrade. 12. The method according to claim 1, characterized in that a vehicle rim preheated to a temperature of 20 to 130 degrees centigrade is used instead of casting to make the semiflexible solid one-piece closed hermetically sealed case. 13. The method according to claim 1, characterized in that a quantity of mixture is emptied inside the rim that occupies 10 to 50% of the inner volume of the rim, closing the lateral opening of the inner circle of the rim with a cover made of any metallic material, wood or various plastic resins. 1

4. The procedure according to the claim 1, characterized in that this rim is placed in the mold holder of a rotational molding machine having two turns in a perpendicular direction with respect to each other with a speed of 10 to 200 revolutions per minute for 15 to 90 minutes. 1

5. -The procedure in accordance with the claim 1, characterized in that the temperature of the resin inside the rim is adjusted from 20 to 130 degrees centigrade 1

6. -The procedure in accordance with the claim 1, characterized in that the piece is allowed to cure at room temperature or heating up to a maximum temperature of 120 ° C, for a period of 6 to 24 hours. 1

7. The procedure according to the claim 1, characterized in that after curing the piece, it is demoulded and left to rest for a period of 24 hours. 1

8. The method according to claim 1, characterized in joining an air valve to the sheath by means of a tube or hose assembled in the valve and sheath. 1

9. The procedure according to the claim 1, characterized in that the chamber is inserted in a normal vehicle rim and subsequently the rim is inserted in the wheel of the vehicle and filled with air under pressure, according to what is specified in the vehicle rim. 20.- A solid, semi-flexible, one-piece sealed, hermetic shell for a polyurethane elastomeric rim that self-pierces the perforations caused by sharp objects, which is inserted inside the normal rim of a vehicle, to avoid the air leakage caused by punctures, characterized in that this chamber is obtained by the method of claim 1. SUMMARY OF THE NONVENTION A procedure is described for manufacturing semi-flexible solid shells of a single piece, hermetically sealed hollow for tires, made of polyurethane elastomeric material, which have the peculiarity of recovering their shape, self-sealing punctures, and covers obtained by said procedure. The method is constituted by the steps of: 1) heating a polymeric resin with a viscosity ranging from 1000 to 25,000 centipoise, and at a temperature ranging from 25 to 120 ° C; 2) place the hot resin in a vacuum chamber, with a vacuum ranging from 1 to 32 inches of mercury, for a time ranging from 5 to 390 minutes; 3) mixing the hot resin with another mixture of catalysts of the socianato and amine type, in an amount of 10 to 80% by weight of any selected mixture of catalysts of this type, for 5 to 20 minutes, at a rate of 60 at 6500 revolutions per minute; 4) to manufacture the semi-flexible, solid, one-piece, hermetically sealed hollow sheath in a mold of two separate pieces that will be joined later, empty a quantity of mixture that occupies 10 to 50% of the volume of the previously prepared mold with a mold release agent and pre-heated At a temperature of 20 to 130 degrees Celsius, the mold is made of any type of metal material or various resins suitable for the manufacture of molds for the emptying of plastic resins, placing the mold in the mold holder of a rotomolding machine that has two different turns in a perpendicular direction with respect to each other and each rotation with a speed of 10 to 200 revolutions per minute for a time of 15 to 90 minutes and adjusting the resin to a temperature of 20 to 130 degrees centigrade; 5) to manufacture the semi-flexible solid one-piece closed hollow tight sleeve inside the rim without using a mold, emptying within the pre-heated rim at a temperature of 20 to 130 degrees centigrade an amount of mixture that occupies 10 to 50% of the inner volume of the rim, closing the lateral opening of the inner circle of the rim with a cover made of any metallic material, wood or various plastic resins, place this rim in the mold holder of a rotomolding machine that has two turns in a perpendicular direction one with respect to the other with a speed of 10 to 200 revolutions per minute for a time of 15 to 90 minutes adjusting the temperature of the resin from 20 to 130 degrees centigrade; 6) let the piece cure at room temperature or heating up to a maximum of 120 ° C, for a period of 6 to 24 hours; 7) After this period, unmold the piece and let it rest for a period of 24 hours; 8) attach a valve for air to the sheath by means of a tube or hose assembled in the valve and sheath; 9) Insert the semi-flexible, solid, one-piece, hermetically sealed hollow sleeve inside a normal vehicle tire, then insert the tire into the vehicle's wheel and fill it with pressurized air, as specified on the vehicle's rim; The one-piece solid watertight closed semi-flexible solid sleeves for tires manufactured with this procedure have the following properties: any section of the chambers can be extended or compressed repeatedly, returning to their original shape and dimensions, self-sealing the perforations caused by bullet impacts, metallic sharp pieces and sharp pieces of rigid materials, preventing air from escaping from inside said rim, and allowing the running of these rims to continue.