JP2010005986A - Method of molding green tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of molding green tires which facilitates handling of a gas-barrier thin film inner liner formed from single layer or laminated structure of a thermoplastic resin film, does not require coating, transfer lamination or the like of a special adhesive layer for bonding a laminate of a film inner liner and a rubber sheet, effectively prevents increase of the number of working processes and the amount of an adhesive used, also simplifies the positioning of the winding start end of the laminate. <P>SOLUTION: When winding the gas-barrier thin inner liner 1 registered in width and an unvulcanized adjacent rubber sheet 3 around the whole circumference of a mold, the winding of the laminate 4 is started in the state where projection part of the edge of unvulcanized adjacent rubber sheet 3 projecting from the inner liner 1 is made to be a part of a winding starting end part 4a to the mold, and the projection part is stuck to the surface of the mold, and bonding its winding termination part 4b to the mold while inserting it into the inner circumference side of the winding starting end part 4a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a green tire molding method, and more particularly to a green tire molding method for manufacturing a tire using a gas barrier thin film film inner liner made of a thermoplastic resin material as an inner liner of a product tire. In particular, the present invention proposes a technique in which a thin film inner liner is wound appropriately and simply and quickly at a predetermined position on a mold.

  As an inner liner that is applied to the inner surface of a tire and functions as an air permeation preventive layer, a rubber layer mainly composed of butyl rubber has been widely used in the past, but in recent years, the weight of the tire has been reduced, etc. For this purpose, for example, as disclosed in Patent Document 1, it is proposed that the inner liner is formed of a gas barrier thin film thermoplastic resin film.

  However, when a belt-shaped thermoplastic resin film having a flat shape is wound around a mold to form an inner liner material, a joining portion of the thermoplastic resin film is generated at one or more locations on the circumference. Thus, since there is a risk of air leakage from the joint portion, Patent Document 2 proposes a technique for forming a thermoplastic resin film forming the inner liner material into a cylindrical shape without the joint portion.

  By the way, when the thermoplastic resin film that forms the inner liner material is pre-formed into a cylindrical shape without a joint, a thermoplastic resin film having various cylindrical dimensions corresponding to the circumference of the green tire to be molded is prepared in advance. In addition to inevitably increasing the cost of the cylindrical thermoplastic film, it is inevitable that many types of film are in stock, and in addition to an increase in inventory management costs, production efficiency is inevitably reduced. There was another problem of being.

  After solving these problems, it is easy to handle a thin resin film in the form of a strip, and the resin film is wound around the mold properly and simply and quickly around the entire circumference. As a conventional technique to be applied, as described in Patent Document 3, at least one end of a laminate formed by joining a layer including at least a resin film layer and a rubber-like elastic body layer via an adhesive layer In addition, there is a technique of using, as a tire member, a circular pipe obtained by transferring and laminating another adhesive layer prepared in advance and overlaying and bonding the other end of the laminate to the other adhesive layer. .

According to this, the layer including the thin resin film layer is backed by the rubber-like elastic body layer, thereby facilitating the handling of the layer including the thin resin film layer and winding the laminate on the mold. Can be performed under excellent workability, so that the efficiency of molding the green tire is improved, and the other end of the laminate is connected to one end via the other adhesive layer. By laminating and laminating to the part, it is possible to advantageously remove the fear of unintentional peeling of the layered joint including the resin film layer, and inventory and inventory management of many types of resin films There is an advantage that it can be made unnecessary.
Japanese Patent No. 3126148 JP 2002-283808 A JP 2007-276631 A

  However, in the prior art described in Patent Document 3, upon bonding one end of the laminate to the other end, the other adhesive layer is attached at the time of bonding or in advance. In addition to the work process that requires transfer and lamination to one of the ends of the laminate and the amount of adhesive used, the layer of the laminate including the resin film layer When starting winding on the molding die peripheral surface with the inner surface side, it is difficult to reliably position and arrange the winding start end of the laminate at a predetermined position on the peripheral surface of the molding die. there were.

  The present invention has been made to solve such problems of the prior art, and the object of the present invention is, for example, a gas barrier that has a single-layer or laminated structure of a thermoplastic resin film. As well as facilitating the handling of the thin film film inner liner, the laminate of the film inner liner and the rubber sheet can be used to join the winding start end portion and winding end portion to the peripheral surface of the mold. This eliminates the need for special adhesive layer application, transfer lamination, etc., effectively preventing an increase in the number of work steps and the amount of adhesive used, and at the same time, the mold peripheral surface at the winding start of the laminate An object of the present invention is to provide a green tire molding method in which a predetermined positioning arrangement on the top is sufficiently simple.

The raw tire molding method according to the present invention includes, for example, a gas barrier thin film film inner liner and an unvulcanized adjacent rubber sheet, both of which have the same width, and their respective edge positions in the length direction. In a state where they are shifted from each other in the extending direction, one or a plurality of laminates that are stuck under the adhesive layer of the film inner liner, over the entire circumference of the mold, When winding it in the circumferential direction, the protruding portion of the unvulcanized adjacent rubber sheet, the edge of which protrudes from the film inner liner, is defined as a part of the winding start end portion of the laminate on the mold. The winding of the laminate is started with the protruding portion directly or indirectly adhered to the surface of the mold, and the winding end portion of the laminate with respect to the mold is the same or other Laminate winding Insert into the inner peripheral side of the start end, and directly connect the end portions of the thin film inner liner and the end portions of the unvulcanized adjacent rubber sheet at positions spaced in the circumferential direction of the mold. In particular, it is in superposition or butt joining.
This molding method is also possible when the width of the thin film inner liner and the unvulcanized rubber sheet are not uniform.

  In this case, the direct overlap bonding between the end portions of the film inner liner is an adhesive on the winding end portion side formed on the film inner liner so that the film inner liner is adhered to the unvulcanized adjacent rubber sheet. It can be performed by joining the winding start end portion side on the layer.

  Then, the overlapping joining of the end portions of the unvulcanized adjacent rubber sheet is performed on the winding end portion side of the unvulcanized adjacent rubber sheet under the adhesive force inherent to the rubber sheet. By joining the protruding portions, butt joining can also be performed by joining the respective end faces of the beginning and end to each other under the adhesive force inherent to the rubber sheet.

  Here, the gas barrier thin film film inner liner is obtained by adding an adhesive layer, for example, over the entire surface of the single layer or laminated structure of the thermoplastic resin film to the rubber sheet. More specifically, the resin material of the film inner liner has a Young's modulus at 23 ° C. in a matrix composed of a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer. Preferably comprises at least a layer made of a resin composition in which a soft resin smaller than the modified ethylene-vinyl alcohol copolymer is dispersed, and further made of an elastomer adjacent to the layer made of the resin composition. Provide one or more auxiliary layers, the thickness of the layer composed of the resin composition It shall be 00 μm or less, and shall have one or more adhesive layers in at least one place between the layer made of the resin composition and the auxiliary layer and between the auxiliary layer and the auxiliary layer. preferable.

  Here, as an adhesive layer which is added to such a thin film inner liner and mainly administers adhesion to an unvulcanized adjacent rubber sheet, it reacts in the molecule with respect to 100 parts by mass of the rubber component. It is preferable to use an adhesive composition in which at least one part of at least one of a maleimide derivative having two or more sites and poly-p-dinitrosobenzene is blended.

By the way, when winding a plurality of laminates composed of a thin film inner liner and an unvulcanized adjacent rubber sheet sequentially around the entire circumference of the mold, The projecting part as a part of the winding start end part is directly attached to the surface of the mold, while the projecting part as a part of the winding start end part of the other laminate is first molded. The thin film-like film inner liner at the winding end portion of one laminate and the non-added film are adhered to the surface of the mold indirectly through the winding end portion of the laminate wound in the circumferential direction. For each end portion of the adjacent rubber sheet, the thin film-like film inner liner at the winding start end portion of the other laminate and each end portion of the unvulcanized adjacent rubber sheet are spaced apart in the circumferential direction of the mold. Directly overlaid Or butt be joined is preferable for the one of the laminate, and when winding over the entire circumference of the mold, to reduce the differences in junction structure.
Here again, the end portions of the film inner liner are directly joined to each other by superimposing the winding start end portion side on the adhesive layer on the winding end portion side of the inner liner. Can do.

  In this case, the unvulcanized adjacent rubber sheet can be used only for ensuring the ease of winding of the thin film-like film inner liner on the mold, etc., but it is adjacent to the film inner liner. Preferably, the rubber sheet is a rubber sheet with an inner liner rubber sheet, a squeegee rubber sheet, or a carcass ply cord embedded therein, which also functions as a functional member of the tire.

  Preferably, each of the joining region between the end portions of the unvulcanized rubber sheet and the joining region between the end portions of the thin film inner liner in the same laminate or between different laminates. The circumferential length of the mold is in the range of 0 to 20 mm and 0 to 60 mm, and the separation distance in the circumferential direction of the mold in their respective joining areas is in the range of 0 to 60 mm. It is preferable.

  In the molding method of the present invention, at the winding start end portion of the laminated body composed of the thin film-like film inner liner and the unvulcanized adjacent rubber sheet that are adhered to each other, the protrusion protrudes from the edge of the thin film-like film inner liner. By sticking the protruding part of the unvulcanized adjacent rubber sheet to the peripheral surface of the mold with the film inner liner facing inward, and winding the laminate around the mold, a thin film film The inner liner is handled easily and easily under the backing of an unvulcanized adjacent rubber sheet, and the required winding around the mold of the film inner liner is performed efficiently and with excellent workability. be able to.

  And in this case, by sticking the protruding portion of the unvulcanized adjacent rubber sheet from the film inner liner to the mold, the laminate, and eventually the winding start of the thin film inner liner, on the mold peripheral surface The positioning and positioning at a predetermined position can be made simple enough, and excellent positioning accuracy can be realized.

Furthermore, in this method, the winding end portion of the laminated body with respect to the mold is inserted into the inner peripheral side of the winding start end portion that is pre-adhered to the peripheral surface of the molding die of the same or another laminated body. Therefore, the end portions of the thin film inner liner and the end portions of the unvulcanized adjacent rubber sheets are overlapped and joined, for example, directly at positions spaced in the circumferential direction of the mold. Therefore, the film inner liners can be joined by the adhesive layer provided in advance on the adjacent rubber sheet side, and the adjacent rubber sheets can be joined by the adhesive force of the rubber sheet itself. It is no longer necessary to newly attach an adhesive to one of the ends, and it is possible to effectively prevent an increase in the number of work steps and an increase in the amount of adhesive used. That.
Therefore, here, the joining region between the end portions of the film inner liner and the joining region between the end portions of the adjacent rubber sheets are located at an interval in the circumferential direction of the mold.

  In order to carry out the above-described method, when a plurality of laminates are used around the mold to wind the laminate around one round, one of the winding start end portions of one laminate is used. While the protruding portion as a part is directly adhered to the peripheral surface of the mold, the winding end of the laminate in which the protruding portion as a part of the winding start end portion of another laminate is wound first Adhering indirectly to the surface of the mold through the part, the other end of the thin film-like film inner liner and the unvulcanized adjacent rubber sheet at the end of winding of one laminate When the end portions of the thin film-like film inner liner and the unvulcanized adjacent rubber sheet at the winding start end portion of the body are directly joined at positions spaced in the circumferential direction of the mold, as described above Can bring about the same effect as The film inner liner is easily and easily handled, and the film inner liner can be easily and quickly wound around the mold with high workability and the film inner liner can be wound. It is possible to easily perform highly accurate positioning on the peripheral surface of the mold at the starting end.

  And here again, it is not necessary to add a new adhesive when joining the winding end portion of one laminate to the winding start end portion of another laminate.

  In the above description, the unvulcanized adjacent rubber sheet is an inner liner rubber sheet, a squeegee rubber sheet, or a rubber sheet in which a carcass ply cord is embedded, which also acts as a functional member of the tire. Sometimes, the purpose is to back the thin film inner liner only, and it is possible to reduce the tire weight compared to the case of using a non-vulcanized adjacent rubber sheet that cannot be a functional member of the tire. In addition, the yield of the rubber material can be improved.

In addition, the circumferential length of the mold was set in the range of 0 to 20 mm in the joining region between the end portions of the unvulcanized adjacent rubber sheets in the same laminated body or between different laminated bodies. When it is possible to sufficiently secure the adhesive bonding allowance between the rubber sheets, when the similar length of the bonding area between the end portions of the thin film inner liner is in the range of more than 0 mm to 60 mm or less, Even when the tire or the like undergoes diameter expansion deformation during shaping, vulcanization, and the like, it is possible to effectively prevent the occurrence of peeling, cracking, and the like at the joint.
On the other hand, if the joining area of the unvulcanized adjacent rubber sheet exceeds 20 mm, the thickness of the rubber sheet in the overlap joining area increases, so that the uniformity and balance of the product tire cannot be denied, and the thin film shape When the bonding area of the film inner liner exceeds 60 mm, there is no particular problem in terms of performance, but a film material is used unnecessarily, and a decrease in material yield, a decrease in economic efficiency, etc. cannot be denied.

  In addition, when the separation distance between the respective joining regions in the circumferential direction of the mold is in the range of 0 to 60 mm, the work for reattaching the rear end portion of the laminate on the mold is performed. Can be made easier. On the other hand, if the peeling distance exceeds 60 mm, the portion previously attached to the mold is peeled off and re-attached, so that workability is deteriorated and the attaching accuracy may be lowered.

  FIG. 1 is a perspective view illustrating a laminate that can be used in the practice of the present invention. In the figure, 1 can be, for example, a single layer or a laminated structure of a thermoplastic resin film. A gas barrier thin film inner liner is shown, and 2 is an adhesive that is applied over the entire surface or a part of the thin film inner liner 1 to the surface of an unvulcanized adjacent rubber sheet to be described later. Indicates the layer.

  Reference numeral 3 denotes a non-added rubber sheet that can be attached to the film inner liner 1 via the adhesive layer 2 and can be a rubber sheet for an inner liner, a rubber sheet for a squeegee rubber, a carcass ply cord embedded therein, or the like. The sulfur adjacent rubber sheet is shown.

This laminated body 4 shown here is in a state in which the widths of the film inner liner 1 and the rubber sheet 3 are made uniform while the end positions in the length direction of both of them are shifted from each other in the extending direction. The film inner liner 1 and the rubber sheet 3 are bonded together with the adhesive layer 2 interposed therebetween.
In addition, the width | variety of the film inner liner 1 and the rubber sheet 3 may not align.

  In carrying out the present invention, in one or a plurality of the laminates 4 as described above, the protruding portion of the rubber sheet 3 from the film inner liner 1 is used as the winding start end of the laminate 4 around the mold. As a part of the portion 4a, for example, when one of the laminates 4 is wound around the peripheral surface of the mold 5 as shown in FIG. As the posture in which 2 is the inside, the projecting portion of the winding start end portion 4a is adhered to position the winding start end of the laminated body 4 on the surface of the molding die, and the molding die 5 is subjected to the rotational displacement under the rotational displacement. On the peripheral surface of the mold 5, the laminate 4 is wound over the entire circumference of the mold 5, and the laminate is wound in advance on the surface of the mold 5 at the end of the winding around the circumference of the mold 5. A state in which the starting end portion 4a is peeled off from the end portion 4a The winding end portion 4b of the laminate 4 is inserted into the inner peripheral side of the winding start end portion 4a as schematically shown in FIG. 3, where the end portions of the thin film inner liner 1 are connected to the adhesive layer. Under the action of 2, for example, they are directly overlapped and joined, and the end portions of the unvulcanized adjacent rubber sheet 3 are directly overlapped and joined, for example, directly under the adhesive force inherent to the rubber sheet 3. These two joints are positioned at intervals in the circumferential direction of the mold 5.

  The gas barrier thin film film inner liner 1 is wound around the peripheral surface of the mold 5 in this manner, thereby facilitating the handling of the thin film film inner liner 1 and applying it to the mold 5. The required winding can be easily performed under high work efficiency, and the protruding portion of the rubber sheet 3 at the winding start end portion of the laminate 4 is adhered to the surface of the mold 5, The winding start end of the laminated body 4, and thus the winding start end of the film inner liner 1 can be accurately positioned at the expected position.

  Further, here, the end portions of the film inner liner 1 are joined to each other through the adhesive layer 2 for adhering the unvulcanized adjacent rubber sheet 3 to the film inner liner 1, and the unvulcanized adjacent rubber sheet. There is an advantage that it is possible to eliminate the need for providing a new adhesive for joining the end portions of the laminated body by joining the end portions of the three pieces to the rubber sheet 3 with an inherent adhesive force.

  By the way, in the place mentioned above, the resin material of the thin film inner liner 1 is at 23 ° C. in a matrix made of a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer. It is preferable to include at least a layer made of a resin composition in which a soft resin having a Young's modulus smaller than that of the modified ethylene-vinyl alcohol copolymer is dispersed. Further, an elastomer is further adjacent to the layer made of the resin composition. An auxiliary layer composed of one or more layers, a thickness of the layer composed of the resin composition of 100 μm or less, and between the layer composed of the resin composition and the auxiliary layer, and the auxiliary It is preferable to provide one or more adhesive layers in at least one place between the layer and the auxiliary layer. .

  The adhesive layer 2 for adhering the unvulcanized adjacent rubber sheet 3 is a maleimide derivative having two or more reactive sites in the molecule and poly-p-dinitrosobenzene with respect to 100 parts by mass of the rubber component. It is preferable to use an adhesive composition in which at least one of these is blended in an amount of 0.1 parts by mass or more.

  Here, when a plurality of laminated bodies 4, for example, two laminated bodies 4 are wound around the circumferential surface of the mold 5 over the entire circumference thereof, the respective laminated bodies 4 are as shown in FIG. When formed, the protruding portion of the rubber sheet 3 as a part of the winding start end portion 4a of one laminated body 4 is directly adhered to the surface of the mold 5, and the laminated body 4 is molded. While winding around the peripheral surface of the mold 5, the protruding portion of the rubber sheet 3 as a part of the winding start end portion 4 a of the other laminate 4 is molded via the winding end portion 4 b of the one laminate 4. By indirectly adhering to the surface of the mold 5, the other end portion of the winding end portion 4 b of one laminate 4 with respect to the respective end portions of the thin film inner liner 1 and the unvulcanized adjacent rubber sheet 3 is The thin film-like film of the winding start end portion 4a of the laminate 4 of FIG. One end of the inner liner 1 and the unvulcanized adjacent rubber sheet 3 can be directly laminated and joined, for example, at positions spaced in the circumferential direction of the mold 5. 4 is preferable in reducing the structural difference between the case where 4 is wound around the entire circumference of the mold 5.

  And even in the case of adopting any of these winding modes, the circumferential length of the mold 5 in the joining area a between the unvulcanized adjacent rubber sheets 3 is in the range of 0 to 20 mm, The similar length of the joining area b between the end portions of the thin film inner liner 1 is preferably in the range of 0 <b ≦ 60 mm.

In addition, the mutual separation distance c in the circumferential direction of the molding die 5 between each of the bonding regions as described above is in the range of 0 to 60 mm, when the rear end portion of the laminate is re-applied. Workability can be improved.
That is, when it exceeds 60 mm, there is a high possibility that the paste may be damaged or the accuracy may be reduced.

It is a perspective view which straddles the laminated body which can be used for implementation of this invention. It is a winding process figure which shows embodiment of this invention. It is a schematic diagram which shows the insertion state of the winding termination | terminus part to the inner peripheral side of the winding start end part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thin film inner liner 2 Adhesive layer 3 Unvulcanized adjacent rubber sheet 4 Laminate 4a Winding start end part 4b Winding end part 5 Mold a, b Joint part c Separation distance

Claims (5)

  A gas barrier thin film inner liner and an unvulcanized adjacent rubber sheet, with their respective edge positions in the length direction being shifted from each other in the extending direction, with the adhesive layer When winding one or more laminates, which are pasted in the middle of the mold, around the mold with the thin film film inner liner inside, the edges are The protruding portion of the unvulcanized adjacent rubber sheet that protrudes from the film inner liner is used as a part of the winding start end portion of the laminate on the mold, and the protruding portion is adhered to the surface of the mold Then, the winding of the laminated body is started, and the winding end portion of the laminated body with respect to the mold is inserted into the inner peripheral side of the winding start end portion of the same or another laminated body to form a thin film inner liner. End portions of the , Each each other end portion of the unvulcanized adjacent rubber sheets directly, the overlay or butt green tire methods molding for joining in spaced locations in the circumferential direction of the mold.   When winding a plurality of laminates around the mold around the entire circumference, the protruding portion as a part of the winding start end portion of one laminate is directly applied to the surface of the mold. While adhering, the protruding portion as a part of the winding start end portion of the other laminate is indirectly adhered to the surface of the mold through the winding end portion of the laminate wound earlier, The thin film film inner liner and the non-vulcanized film inner liner at the winding start end of the other laminate are respectively attached to the end portions of the thin film film inner liner and the unvulcanized adjacent rubber sheet at the winding end portion of one laminate. The raw tire molding method according to claim 1, wherein the respective end portions of the sulfur adjacent rubber sheet are directly overlapped or butted and joined at positions spaced in the circumferential direction of the molding die.   The raw tire molding method according to claim 1 or 2, wherein the unvulcanized adjacent rubber sheet is a rubber sheet for an inner liner, a rubber sheet for a squeegee rubber, or a rubber sheet in which a carcass ply cord is embedded.   Overlap or butt joint area between end parts of unvulcanized rubber sheet and end part of thin film inner liner in the same laminate or between different laminates The method for molding a raw tire according to any one of claims 1 to 3, wherein the length of each of the regions in the circumferential direction of the mold is in the range of 0 to 20 mm and more than 0 mm to 60 mm or less.   The circumferential distance of the mold is set in the range of 0 to 60 mm between the joining region between the end portions of the unvulcanized adjacent rubber sheet and the joining region between the end portions of the thin film inner liner. 4. The method for molding a green tire according to any one of 4 above.

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