JP5834616B2 - Pneumatic tire manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a pneumatic tire.

More specifically, a laminate sheet in which a sheet made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer, and a rubber that is vulcanized and bonded to the thermoplastic resin or the thermoplastic resin composition is laminated. In a method of cutting a predetermined length, splicing the end of the laminate sheet, and further manufacturing a pneumatic tire through vulcanization molding, after the pneumatic tire manufactured by the method starts running, The present invention relates to a method for producing a pneumatic tire that does not generate cracks in the vicinity of a splice portion of a spliced laminate sheet and that can exhibit the characteristics and performance of the laminate sheet with good durability over a long period of time.

  The laminate sheet typically constitutes an inner liner layer which is one of important members in recent pneumatic tires, for example. In that case, the present invention is a pneumatic tire having an inner liner layer formed from the laminate sheet as described above, and the spliced laminate sheet (inner liner layer) after the running of the pneumatic tire is started. ) And a pneumatic tire manufacturing method and a pneumatic tire excellent in durability of the inner liner layer.

  In addition to the inner liner layer, the laminate sheet can be used at each important position in the tire as a member for weight reduction and reinforcement of the tire, for example, without a significant increase in weight. . In that case, the present invention is a method for manufacturing a pneumatic tire using the reinforcing sheet formed from the laminate sheet as described above, and cracks are not generated in the vicinity of the splice portion of the spliced reinforcing sheet. The present invention relates to a pneumatic tire manufacturing method and a pneumatic tire capable of exhibiting the effect of the reinforcing sheet with high durability.

  In recent years, it has been proposed and studied to use a sheet-like material made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer for an inner liner of a pneumatic tire (Patent Document 1).

  When a sheet-like material comprising a thermoplastic resin composition or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer is actually used for an inner liner of a pneumatic tire, the thermoplastic resin or the thermoplastic resin and the elastomer are usually used. And a laminate sheet of a rubber (tie rubber) sheet that is vulcanized and bonded to the thermoplastic resin or a thermoplastic resin composition blended with a thermoplastic resin and an elastomer. A manufacturing method is adopted in which the product is wound around a molding drum, lap spliced, and used for a tire vulcanization molding process.

  However, the laminated sheet wound in the form of a roll-shaped winding body is cut out by pulling a required length from the roll-shaped winding body, wound around a tire molding drum, and wrapped on the drum. Further, when the tire is manufactured by further vulcanization molding, a sheet of the thermoplastic resin or thermoplastic resin composition constituting the inner liner after starting the tire running, and the thermoplastic resin or thermoplastic resin composition In some cases, the sheet and the vulcanized and bonded tie rubber sheet peeled off.

  This will be described with reference to the drawings. As shown in FIG. 2 (a), a laminate sheet 1 comprising a sheet 2 made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer, and a tie rubber layer 3. Is cut into a required size (length) with a blade or the like, and lap spliced on the tire forming drum so as to form a ring by providing lap splice portions S at both ends thereof. The laminate sheet 1 is formed so that both ends thereof are lap-spliced to form an annular shape when one sheet is used, or the ends of each other are wrapped when used in a plurality of sheets. A plurality of sheets are spliced to form one ring.

  Further, a part material (not shown) necessary for manufacturing the tire is wound and vulcanized with a bladder.

  After the vulcanization molding, as shown in a model diagram in FIG. 2B, an inner liner layer comprising a sheet 2 of a thermoplastic resin composition obtained by blending a thermoplastic resin or a thermoplastic resin and an elastomer, and a tie rubber layer 3 10 is formed, and in the vicinity of the lap splice portion S, a portion where the sheet 2 made of a thermoplastic resin or a thermoplastic resin composition is exposed and a portion embedded in the tie rubber layer is formed.

  The phenomenon in which the above-described thermoplastic resin or thermoplastic resin composition sheet 2 and the vulcanized bonded tie rubber sheet 3 are peeled off is particularly the thermoplastic resin or the heat shown in FIG. The sheet 2 of the plastic resin composition is exposed and is generated in the vicinity of the front end portion 4 and the like. First, a crack is generated, which further proceeds to a peeling phenomenon of the sheet 2.

  In the above description, the case where the laminate sheet 1 made of the thermoplastic resin or the thermoplastic resin composition 2 and the tie rubber layer 3 is used as the inner liner layer has been described. The same applies to the case where the tire is used as a sidewall portion (not shown) of the tire or a reinforcing sheet layer (not shown) disposed in the entire circumferential direction on the tire outer peripheral side of the inner liner layer. In particular, the tire portion in which the laminated sheet as described above is arranged as a reinforcing sheet layer is usually used under severe conditions such as being repeatedly loaded over a long period of time, and cracks and peeling It often involves problems such as the occurrence of

JP 2009-241855 A

In view of the above-described points, an object of the present invention is to provide a sheet made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer, and the thermoplastic resin or thermoplastic resin composition and vulcanized adhesive. An air having an inner liner layer or a reinforcing sheet layer formed from the laminated sheet after wrapping a splice (splicing performed by providing overlapping portions) at the end of the laminated sheet laminated with the rubber to be laminated In the method of manufacturing a filled tire, cracks and separation may occur in the vicinity of the splice portion of the spliced laminate sheet (inner liner layer or reinforcing sheet layer) after starting the travel of the manufactured pneumatic tire. And exhibits the properties and performance of the laminate sheet for a long time with good durability. And to provide a manufacturing method of a pneumatic tire that.

The manufacturing method of the pneumatic tire of the present invention which achieves the object mentioned above has the following composition (1).
(1) An end of a laminate sheet in which a thermoplastic resin or a sheet made of a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer, and a rubber that is vulcanized and bonded to the thermoplastic resin or the thermoplastic resin composition are laminated. In a method for manufacturing a pneumatic tire, the method includes the step of vulcanizing and bonding the rubber and the sheet made of the thermoplastic resin or the thermoplastic resin composition by performing vulcanization molding of the tire after lap splicing by overlapping, after the vulcanization adhesion, production of pneumatic tires, which comprises the above sharpening process cutting the said sheet tip to the buffing in the front end of the sheet made of the thermoplastic resin or the thermoplastic resin composition Method.

Moreover, in the manufacturing method of the pneumatic tire of this invention, it is preferable to take the structure in any one of following (2)-(7).
(2) The thickness T (mm) at the position where the sharpening treatment is located inward by (t × 3) length from the front end of the sheet made of the thermoplastic resin or the thermoplastic resin composition is 0 The manufacturing method of a pneumatic tire according to the above (1), wherein the relationship satisfies .05t ≦ T ≦ 0.8t.

here,
t: tire circumferential direction average thickness (mm) of a non-sharpened portion of a sheet comprising a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer
T: thickness of the sheet (mm) at a position that is inward (t × 3) from the front end of the sheet made of the thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer.

(3) A tire length X (mm) in the tire circumferential direction made of the thermoplastic resin or thermoplastic resin composition scraped by the buffing is a lap length L (mm) in the tire circumferential direction, and the following (a) The method for producing a pneumatic tire according to the above (1) or (2), wherein the relationship satisfies the formula.
X (mm) ≦ L (mm) ......... (a)
(4) The buff depth shaved by the buffing is D (mm), from the thermoplastic resin or thermoplastic resin composition in the overlapping part of the sheet made of the thermoplastic resin or thermoplastic resin composition When the thickness of the rubber sandwiched between the sheets is G (mm) and the thickness of the sheet made of the thermoplastic resin or thermoplastic resin composition is t (mm), they satisfy the following formula (b) The method for producing a pneumatic tire according to any one of the above (1) to (3), characterized in that:
D <(G + t) ......... (b)
(5) The thermoplastic resin comprises at least one of polyamide resin, polyester resin, polynitrile resin, polymethacrylate resin, polyvinyl resin, cellulose resin, fluorine resin, and imide resin. The method for producing a pneumatic tire according to any one of the above (1) to (4), characterized in that:
(6) The above-mentioned (1), wherein the elastomer comprises at least one of diene rubber, hydrogenated diene rubber, halogen-containing rubber, silicon rubber, sulfur-containing rubber, fluororubber and thermoplastic elastomer. )-(5) The manufacturing method of the pneumatic tire in any one of.
(7) One or a plurality of the laminate sheets are used, and in the case of one sheet, both end portions thereof are lap spliced in the case of a plurality of sheets, and (1) )-(6) The manufacturing method of the pneumatic tire in any one of.

The pneumatic tire obtained by the present invention has the following configuration (8).
(8) In a pneumatic tire having a laminated sheet member in which a sheet made of a thermoplastic resin composition obtained by blending a thermoplastic resin or a thermoplastic resin and an elastomer and a rubber layer are laminated and vulcanized and bonded together, ends of the laminated sheet member is wrapped splice, and the leading edge of the sheet made of the thermoplastic resin or the thermoplastic resin composition of the lap splice is, after being the vulcanization, previously sharpness is subjected to buffing A pneumatic tire characterized in that it is treated.

  According to the first aspect of the present invention, a sheet made of a thermoplastic resin composition obtained by blending a thermoplastic resin or a thermoplastic resin and an elastomer, and a rubber that is vulcanized and bonded to the thermoplastic resin or the thermoplastic resin composition. Air produced in a method for producing a pneumatic tire having an inner liner layer or a reinforcing sheet layer formed from the laminated sheet by lap splicing at the end of the laminated sheet and further vulcanization molding After the start of running the tire, there is no occurrence of cracks or peeling near the lap splice portion of the spliced laminate sheet (inner liner layer or reinforcing sheet layer). Provided is a method for producing a pneumatic tire capable of exhibiting good performance with good durability over a long period of time.

  According to the present invention according to any one of claims 2 to 4, there is provided a method for manufacturing a pneumatic tire that has the effects of the method of the present invention according to claim 1 and that can clearly demonstrate the effects. .

  According to the present invention of claim 5, while having the effect of the method of the present invention of claim 1, the thermoplastic resin is appropriately selected to provide gas permeability, durability, flexibility, heat resistance, processing. A sheet made of a thermoplastic resin or a thermoplastic resin composition that satisfies required physical properties such as properties can be produced, and a method for producing a pneumatic tire using the sheet as a member is provided.

  According to the sixth aspect of the present invention, the thermoplastic resin having the effects of the method of the present invention according to the first aspect and satisfying the required physical properties such as durability, flexibility and workability by appropriately selecting an elastomer. A sheet made of the resin composition can be produced, and a method for producing a pneumatic tire using the sheet as a member is provided.

  According to this invention concerning Claim 7, while having the effect of the method of this invention concerning Claim 1, according to the size of a tire, the amount of laps of the lap splice part of a laminated sheet (overlapping portion of tire) The manufacturing method of the pneumatic tire which can manufacture pneumatic tires of various sizes is provided by appropriately changing the circumferential length) and the number of used laminate sheets.

According to the present invention , a laminate sheet in which a sheet made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer, and a rubber that is vulcanized and bonded to the thermoplastic resin or the thermoplastic resin composition are laminated. In the pneumatic tire having the inner liner layer or the reinforcing sheet layer formed from the laminate sheet, after starting the running of the manufactured pneumatic tire, In the vicinity of the lap splice part of the spliced laminate sheet (inner liner layer or reinforcing sheet layer), there is no occurrence of cracks or peeling, and the properties and performance of the laminate sheet have good durability over a long period of time. A pneumatic tire that can be satisfactorily exhibited is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the manufacturing method and pneumatic tire of the pneumatic tire of this invention, (a) is the state (state before sharpening process) after carrying out the vulcanization molding by lap splicing the edge part of a laminated body sheet | seat ) Is a model diagram, and (b) is the front end of the sheet 2 made of the thermoplastic resin composition in the laminate sheet after the vulcanization molding shown in (a) (before the sharpening treatment). It is a model figure which expanded and showed the neighborhood, (c) is buffing near the front-end | tip vicinity of the sheet | seat 2 which consists of a thermoplastic resin or a thermoplastic resin composition in the laminated body sheet | seat shown in (b). it is a model diagram showing a state after the previous sharpening process cutting the. It is a figure explaining the method other than this invention, (a) is the sheet | seat 2 which consists of a thermoplastic resin or a thermoplastic resin composition by which the front-end | tip is not sharpened, and this thermoplastic resin or a thermoplastic resin composition Is a model diagram showing a state in which a laminate sheet 1 in which rubber 3 to be vulcanized and bonded is laminated is cut at a predetermined length, wound around a tire forming drum, and both ends of the laminate sheet 1 are lap-spliced. b) is a model diagram showing a state after vulcanization molding in the state shown in (a). BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially broken perspective view showing an example of a form of a pneumatic tire according to a method for manufacturing a pneumatic tire of the present invention.

  Hereinafter, the present invention will be described in more detail.

The method for producing a pneumatic tire according to the present invention includes a sheet 2 made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer, and a rubber that is vulcanized and bonded to the thermoplastic resin or the thermoplastic resin composition. After the end portion of the laminate sheet 1 laminated with 3 is lapped by overlap, the sheet made of the thermoplastic resin or the thermoplastic resin composition and the rubber are vulcanized and bonded by performing vulcanization molding of a tire. the method of manufacturing a pneumatic tire having a step, the pressure after vulcanization adhesion to the said thermoplastic resin or a thermoplastic resin composition to the buffing in the leading end of the sheet 2 before sharpening process cutting the said sheet tip It is characterized by doing.

The pneumatic tire of the present invention is a laminated sheet in which a sheet 2 made of a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer and a rubber layer 3 are laminated and vulcanized and bonded together. In a pneumatic tire having a member, ends of the laminated sheet member are lap spliced, and a tip of the sheet made of the thermoplastic resin or the thermoplastic resin composition in the lap splice portion is vulcanized and bonded. later, it is characterized in that it is subjected to buffing is previously sharpening process.

  The inventors have disadvantages of the conventional method, for example, a thermoplastic resin constituting an inner liner layer or a thermoplastic resin composition sheet in which an elastomer is blended in a thermoplastic resin, and a thermoplastic resin or As a result of various investigations on the cause of peeling between the thermoplastic resin composition sheet and the vulcanized bonded tie rubber sheet, the following knowledge was obtained.

  That is, when the above-described laminate sheet 1 is prepared by a normal method, the rigidity existing above and below the lap splice portions S at both ends of the laminate sheet 1 shown in FIGS. A large stress is generated in the rubber portion sandwiched between the large thermoplastic resin or the thermoplastic resin composition sheet 2 in which the elastomer is blended with the thermoplastic resin, and therefore, the thermoplastic resin or the thermoplastic resin composition sheet 2 It was considered that cracks occurred in the vicinity of the tip 4 or the like, and that the cracks were further increased and peeling occurred.

On the other hand, in the method for producing a pneumatic tire according to the present invention, the thermoplastic tire or the thermoplastic resin composition is further used for the state shown in FIG. 2B after vulcanization molding. formed by the buffing the leading end of the sheet 2 is to the previous sharpening process cutting the said sheet tip.

  This will be further described with reference to FIG. 1. FIG. 1 (a) shows a state after the end of the same laminate sheet as in FIG. 2 (b) is lap spliced and vulcanized (a state before sharpening treatment). It is the model figure which showed. In this figure, for the overlap spliced portion, the lap length L (mm) in the tire circumferential direction, and the thickness of the rubber 3 sandwiched between the sheets 2 made of a thermoplastic resin or a thermoplastic resin composition are expressed as G ( mm), and t (mm) represents the thickness of the sheet 2 made of a thermoplastic resin or a thermoplastic resin composition.

FIG. 4B is a model diagram of the vicinity of the buffing area shown in an enlarged manner near the front end of the sheet 2 made of the thermoplastic resin or thermoplastic resin composition shown in FIG. and buffing the tip vicinity of a thermoplastic resin or a thermoplastic resin composition consisting of compounds sheet 2 of the stack in the sheet shown in b) shows a state after the previous sharpening process cutting the said sheet tip.

The present invention, by the above sharpening process cutting the said sheet tip buffed such pressurized thermoplastic resin or near the tip of the thermoplastic resin composition consisting of compounds sheet 2 after curing, relief of stress, and cracks The remarkable effect of suppressing the occurrence of a peeling phenomenon between the thermoplastic resin or thermoplastic resin composition sheet 2 and the tie rubber sheet 3 after the start of use of the tire is eliminated. Demonstrate.

  In the present invention, “buffing and sharpening the tip of the sheet” means that the tip of the sheet is physically ground using a buff or file, a grinder, etc. Say. The processing operation may be performed manually as well as by a machine / device. As shown in a model in FIG. 1 (c), for example, by buffing using a rotating buff, when viewed from the side, an arcuate part B is formed, and the leading edge of the sheet is The portion B has a sharpened portion 5 that gradually becomes thinner toward the tip, and buffing is performed on the cut end portion of the sheet 2 so as to have such a side shape. To do.

  The above-mentioned “sharpening process” may be such that some roundness or corners remain in the vicinity of the most leading edge of the sheet 2, and even if such roundness or corners remain, the whole is sharpened. If it is processed so that it can be said that it has a shape, the effect of suppressing the occurrence of cracks and peeling as described above is noticeable.

  As described above, the sharpening process at the front end of the sheet 2 is effective even when the roundness or the corners remain slightly at the front end. In particular, in order to stably obtain a high effect, the sharpening process is performed. However, the thickness T (mm) at the position which is inward by (t × 3) length from the front end of the sheet 2 made of the thermoplastic resin or the thermoplastic resin composition obtained by blending an elastomer in the thermoplastic resin. , 0.05t ≦ T ≦ 0.8t is preferably satisfied.

Where t and T are respectively
t: tire circumferential direction average thickness (mm) of a non-sharpened portion of a sheet comprising a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer
T: the thickness (mm) of the sheet at the position (t × 3) inward from the front end of the sheet made of thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer. This is as shown in FIG.

  Further, as shown in FIGS. 1A and 1C, the sheet length X (mm) in the tire circumferential direction of the sheet 2 made of a thermoplastic resin or a thermoplastic resin composition scraped by buffing is determined as follows. It is preferable that the wrap length L (mm) in the direction and the following formula (a) are satisfied.

That is, the sharpening treatment that the sharpened portion becomes longer than the length of the overlapping portion in the tire circumferential direction may lose the original operation and effect of using the laminated sheet. It is not preferable. For example, in the case of an inner liner, a non-overlapping region may occur, and thus air leakage may deteriorate.
X (mm) ≦ L (mm) ......... (a)

Similarly, the upper and lower thermoplastic resins or thermoplastic resin compositions in the overlapping part of the sheet 2 made of a thermoplastic resin or a thermoplastic resin composition has a buff depth cut by buffing of D (mm). When the thickness of the rubber layer 3 sandwiched between the sheets 2 made of G is (mm) and the thickness of the sheet 2 made of a thermoplastic resin or a thermoplastic resin composition is t (mm), they are the following (b ) It is preferable that the relationship satisfies the formula.
D <(G + t) ......... (b)
A more preferable range of the buff depth D (mm) is a range represented by the following formula (c).
0.7 × t ≦ D ≦ 1.2 × t (c)

  That is, even if the depth D (mm) is slightly shallower than the thickness t (mm) of the sheet 2 made of the thermoplastic resin or the thermoplastic resin composition, the effect of the present invention can be exhibited. The range of the formula is most preferable from the viewpoint of ease of processing, the strength of the laminated sheet, and the like.

  Further, the buffing is not necessarily performed on all the tips of the sheet 2 made of the thermoplastic resin or the thermoplastic resin composition of the lap splice portion, and appropriately, on the portion where the effect of the present invention can be exerted more greatly. You may make it carry out by giving priority only to. Since it is performed after vulcanization molding, it may not be possible to perform buffing well on all the tips, to be performed on the exposed part on the inner and outer surfaces, and to a part of that This is because the effect in that part can be obtained even by performing. The size of the abrasive grains used for buffing (buffing) may be the same as that used for ordinary metal products, rubber products, resin products and the like. Since it is a buffing with respect to a thermoplastic resin or a thermoplastic resin composition and rubber, it is not necessary to use special abrasive grains and abrasives.

  FIG. 3 is a partially broken perspective view showing an example of the form of the pneumatic tire according to the method for manufacturing a pneumatic tire of the present invention.

  The pneumatic tire T is provided so that the sidewall portion 12 and the bead portion 13 are connected to the left and right of the tread portion 11. A carcass layer 14 that is a skeleton of the tire is provided inside the tire so as to straddle between the left and right beads 13 in the tire width direction. Two belt layers 15 made of steel cord are provided on the outer peripheral side of the carcass layer 4 corresponding to the tread portion 11. An arrow Y indicates the tire circumferential direction. An inner liner layer 10 formed by lap splicing according to the method of the present invention is disposed inside the carcass layer 14, and a lap splice portion S (common to S in FIGS. 1 and 2) extends in the tire width direction. Exist.

  In the pneumatic tire according to the present invention, a crack or a thermoplastic resin or a thermoplastic resin composition in which the inner liner layer 10 is formed in the vicinity of the lap splice portion S on the inner peripheral surface of the tire. The occurrence of cracks between the sheet 2 and the tie rubber layer 3 and the occurrence of peeling are suppressed, and the durability is remarkably improved.

  The above-described effects obtained by the manufacturing method of the pneumatic tire of the present invention and the pneumatic tire of the present invention are obtained even when the above-described laminate sheet is used not as an inner liner layer but as a reinforcing sheet in the pneumatic tire. This is the same as long as it has a lap splice portion S. For example, the same applies to the case where the tire is used as a sidewall portion (not shown) of the tire, or a reinforcing sheet layer (not shown) disposed in the entire circumferential direction on the tire outer peripheral side of the inner liner layer.

  Although the overlap length of the lap splice part S depends on the tire size and the place where it is used, it is generally preferably about 7 to 20 mm, more preferably about 8 to 15 mm. This is because if the overlap length is too long, the uniformity of the tire is deteriorated, and if it is too short, the splice portion may open during molding or the like.

  The laminate sheet is not limited to a single sheet, and one or a plurality of sheets are used. In the case of a single sheet, both end portions thereof are lap-spliced. It may be spliced to form one ring. If the overlap length of the lap splice portion S and the number of laminated sheets used are appropriately set, the manufacturing method of the present invention can be applied in the manufacture of pneumatic tires of all dimensions, and the expected effects of the present invention. This can also be said to be a great effect of the present invention.

  Examples of the thermoplastic resin that can be used in the present invention include polyamide resins [for example, nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12). , Nylon 610 (N610), nylon 612 (N612), nylon 6/66 copolymer (N6 / 66), nylon 6/66/610 copolymer (N6 / 66/610), nylon MXD6 (MXD6), nylon 6T, nylon 9T, nylon 6 / 6T copolymer, nylon 66 / PP copolymer, nylon 66 / PPS copolymer] and their N-alkoxyalkylated products, for example, methoxymethylated products of nylon 6, nylon 6 / 610 copolymer methoxymethylated product, nylon 612 methoxymethylated product, polyester Resin [for example, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), PET / PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, poly Aromatic polyester such as oxyalkylene diimide diacid / polybutylene terephthalate copolymer], polynitrile resin [for example, polyacrylonitrile (PAN), polymethacrylonitrile, acrylonitrile / styrene copolymer (AS), (meth) acrylonitrile / Styrene copolymer, (meth) acrylonitrile / styrene / butadiene copolymer], polymethacrylate resins [for example, polymethyl methacrylate (PMMA), polyethyl methacrylate], polyvinylidene Resin [for example, vinyl acetate, polyvinyl alcohol (PVA), vinyl alcohol / ethylene copolymer (EVOH), polyvinylidene chloride (PDVC), polyvinyl chloride (PVC), vinyl chloride / vinylidene chloride copolymer, vinylidene chloride / Methyl acrylate copolymer, vinylidene chloride / acrylonitrile copolymer (ETFE)], cellulose resin [eg, cellulose acetate, cellulose acetate butyrate], fluorine resin [eg, polyvinylidene fluoride (PVDF), polyvinyl fluoride ( PVF), polychlorofluoroethylene (PCTFE), tetrafluoroethylene / ethylene copolymer], an imide resin [for example, aromatic polyimide (PI)] and the like can be preferably used.

  In particular, the thermoplastic resin contains at least one of a polyamide resin, a polyester resin, a polynitrile resin, a polymethacrylate resin, a polyvinyl resin, a cellulose resin, a fluorine resin, and an imide resin. It is preferable because it satisfies the required physical properties such as durability, flexibility, heat resistance, workability, and gas permeability.

  Moreover, what was mentioned above about a thermoplastic resin can be used for the thermoplastic resin and elastomer which comprise the thermoplastic resin composition which can be used by this invention. Examples of the elastomer include diene rubber and hydrogenated products thereof [for example, natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR, high cis BR and Low cis BR), nitrile rubber (NBR), hydrogenated NBR, hydrogenated SBR], olefin rubber [for example, ethylene propylene rubber (EPDM, EPM), maleic acid modified ethylene propylene rubber (M-EPM), butyl rubber (IIR) ), Isobutylene and aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), ionomer], halogen-containing rubber [for example, Br-IIR, CI-IIR, brominated isobutylene-p-methylstyrene copolymer ( BIMS), chloroprene rubber (CR), hydrin rubber (CHR) Chlorosulfonated polyethylene rubber (CSM), chlorinated polyethylene rubber (CM), maleic acid modified chlorinated polyethylene rubber (M-CM)], silicone rubber [eg methyl vinyl silicone rubber, dimethyl silicone rubber, methyl phenyl vinyl silicone rubber ], Sulfur-containing rubber (for example, polysulfide rubber), fluorine rubber (for example, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicon rubber, fluorine-containing phosphazene rubber), heat Plastic elastomers (for example, styrene elastomers, olefin elastomers, ester elastomers, urethane elastomers, polyamide elastomers) and the like can be preferably used. Among them, it is preferable to use an elastomer comprising at least one of diene rubber, hydrogenated diene rubber, halogen-containing rubber, silicon rubber, sulfur-containing rubber, fluororubber and thermoplastic elastomer. It is preferable to satisfy required physical properties such as heat resistance and workability.

  In addition, when blending with the combination of the specific thermoplastic resin described above and the specific elastomer described above, if the compatibility is different, it is possible to compatibilize both using a suitable compatibilizing agent as the third component. it can. By mixing a compatibilizing agent with the blend system, the interfacial tension between the thermoplastic resin and the elastomer is reduced, and as a result, the particle size of the elastomer forming the dispersion layer becomes fine. It will be expressed more effectively. As such a compatibilizing agent, a copolymer having a structure of both a thermoplastic resin and an elastomer or one of them, or an epoxy group, a carbonyl group, a halogen group, and an amino group that can react with the thermoplastic resin or elastomer are generally used. In addition, a copolymer having a oxazoline group, a hydroxyl group and the like can be taken. These may be selected according to the type of thermoplastic resin and elastomer to be blended, but those commonly used include styrene / ethylene butylene block copolymer (SEBS) and its maleic acid modification, EPDM, EPM, EPDM / styrene or EPDM / acrylonitrile graft copolymer and its modified maleic acid, styrene / maleic acid copolymer, reactive phenoxin and the like can be mentioned. The amount of the compatibilizing agent is not particularly limited, but is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymer component (the total of the thermoplastic resin and the elastomer).

  In the thermoplastic resin composition in which the thermoplastic resin and the elastomer are blended, the composition ratio of the specific thermoplastic resin and the elastomer is not particularly limited, and the elastomer is used as a discontinuous phase in the thermoplastic resin matrix. What is necessary is just to determine suitably so that a disperse | distributed structure may be taken, and a preferable range is 90 / 10-30 / 70 by weight ratio.

  In the present invention, the thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer can be mixed with another polymer such as a compatibilizing agent as long as the necessary properties as an inner liner or a reinforcing member are not impaired. The purpose of mixing other polymers is to improve the compatibility between the thermoplastic resin and the elastomer, to improve the molding processability of the material, to improve the heat resistance, to reduce the cost, etc. Examples of the material that can be used include polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS, SBS, and polycarbonate (PC). In addition, fillers (calcium carbonate, titanium oxide, alumina, etc.) generally incorporated into polymer blends, reinforcing agents such as carbon black and white carbon, softeners, plasticizers, processing aids, pigments, dyes, and aging An inhibitor or the like can be arbitrarily blended as long as necessary characteristics as an inner liner are not impaired. The thermoplastic resin composition has a structure in which an elastomer is dispersed as a discontinuous phase in a matrix of a thermoplastic resin. By adopting such a structure, it is possible to provide the inner liner or the reinforcing member with sufficient flexibility and the effect of the resin layer as a continuous phase, and at the same time with molding, regardless of the amount of elastomer. Molding processability equivalent to that of a thermoplastic resin can be obtained.

  The Young's modulus of the thermoplastic resin and elastomer that can be used in the present invention is not particularly limited, but both are preferably 1 to 500 MPa, more preferably 50 to 500 MPa.

Examples 1-7, Comparative Example 1
Hereinafter, the manufacturing method of the pneumatic tire and the pneumatic tire of the present invention will be specifically described with reference to examples and the like.

  As shown in Table 1, as a sheet of the thermoplastic resin composition, N6 / 66 is used as the thermoplastic resin, BIMS is used as the elastomer, and the thickness (t) is made of a thermoplastic resin composition blended at 50/50. ) A sheet having a melting point of 0.13 mm and a melting point of 190 ° C. was prepared.

  On the other hand, a tie rubber having a composition as shown in Table 2 and having a thickness of 0.7 mm was prepared as the tie rubber layer.

The sheet of the thermoplastic resin composition and the tie rubber layer were evaluated using the pneumatic tire as an inner liner layer in the following procedure.
(A) Preparation of the thermoplastic resin composition sheet (t = 0.13 mm),
(B) Production of a rubber layer to be vulcanized and bonded to the thermoplastic resin composition sheet,
(C) Preparation of a laminate by pre-assembling the thermoplastic resin composition sheet and a rubber layer,
(D) Splicing the laminate on a molding drum and vulcanizing to produce a tire;
(E) Buff the tip of the thermoplastic resin composition sheet exposed on the tire lumen side surface under the conditions of Examples and Comparative Examples described in Table 3 (file # 400, manual work). previous sharpening processing by the processing,
(F) After the tire durability test (predetermined running test) for the manufactured tire, the degree of occurrence of cracks and peeling at the splice portion was evaluated.

  In addition, 215 / 70R15 98H was used as the test tire, and two tires were prepared for each example and comparative example, which were attached to a JATMA standard rim 15 × 6.5JJ, and the tire internal pressure was set to JATMA maximum air pressure (240 kPa). It was.

Evaluation of the test tires, as an inner liner layer of the lumen of each test tire, which has adopted the distal destination sharpening laminate sheet according to the present invention, occurrence of cracks in the vicinity of the splice, the occurrence of peeling We compared it with other situations. After running the pneumatic tire at 50,000 km at 7.35 kN, evaluation was made on the occurrence of cracks / peeling and air leakage.

  The results are shown in Table 3. The effect (the effect of suppressing the occurrence of cracks and peeling) was evaluated in four stages: “excellent”, “good”, “good”, and “impossible”. The air leakage is performed by index evaluation with Comparative Example 1 being 100, and the larger the numerical value, the worse the air leakage.

  In each of the embodiments of the present invention, no problem occurred in the vicinity of the splice portion or any other place even after traveling 50,000 km. In Examples 5 and 7, the air leakage was inferior to 105 and 110 as compared with the other examples, but it was sufficiently good compared with the conventional inner liner of butyl rubber, and it can be judged that there is no particular problem. was.

1: Laminate sheet 2: Thermoplastic resin or a thermoplastic resin composition sheet obtained by blending a thermoplastic resin and an elastomer 3: Tie rubber layer 4: Near the tip of the thermoplastic resin or thermoplastic resin composition sheet 2 5: Sharpened portion 10: inner liner layer 11: tread portion 12: sidewall portion 13: bead 14: carcass layer 15: belt layer S: wrap splice portion Y: tire circumferential direction

Claims (7)

Overlay the end of the laminate sheet that is a laminate of a thermoplastic resin or a thermoplastic resin composition blended with a thermoplastic resin and an elastomer, and the thermoplastic resin or rubber that is vulcanized and bonded to the thermoplastic resin composition. In the method for manufacturing a pneumatic tire, the method includes the step of vulcanizing and bonding the rubber and the sheet made of the thermoplastic resin or the thermoplastic resin composition by vulcanizing and molding the tire after lap splicing with a lap. after the vulcanization adhesive, pneumatic tire manufacturing method, characterized by the previous sharpening process to the buffing in the front end of the sheet made of the thermoplastic resin or the thermoplastic resin composition cut the sheet tip. When the sharpening treatment is performed, a thickness T (mm) at a position (t × 3) inward from the front end of the sheet made of the thermoplastic resin or the thermoplastic resin composition is 0.05 t ≦ 2. The method for manufacturing a pneumatic tire according to claim 1, wherein the relationship satisfies T ≦ 0.8t.
here,
t: tire circumferential direction average thickness (mm) of a non-sharpened portion of a sheet comprising a thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer
T: thickness of the sheet (mm) at a position that is inward (t × 3) from the front end of the sheet made of the thermoplastic resin or a thermoplastic resin composition obtained by blending a thermoplastic resin and an elastomer. The tire circumferential direction sheet length X (mm) made of the thermoplastic resin or thermoplastic resin composition scraped by the buffing satisfies the tire circumferential direction lap length L (mm) and the following formula (a): The method for producing a pneumatic tire according to claim 1, wherein the pneumatic tire has a relationship of
X (mm) ≦ L (mm) ......... (a) The buff depth cut by the buffing is D (mm), and the sheet made of the thermoplastic resin or the thermoplastic resin composition in the overlapping portion of the sheet made of the thermoplastic resin or the thermoplastic resin composition is used. When the thickness of the sandwiched rubber is G (mm) and the thickness of the sheet made of the thermoplastic resin or thermoplastic resin composition is t (mm), they satisfy the following formula (b): The method for producing a pneumatic tire according to any one of claims 1 to 3, wherein the method is provided.
D <(G + t) ......... (b)   The thermoplastic resin comprises at least one of a polyamide resin, a polyester resin, a polynitrile resin, a polymethacrylate resin, a polyvinyl resin, a cellulose resin, a fluorine resin, and an imide resin. The manufacturing method of the pneumatic tire in any one of Claims 1-4.   6. The elastomer according to claim 1, wherein the elastomer comprises at least one of diene rubber, hydrogenated diene rubber, halogen-containing rubber, silicon rubber, sulfur-containing rubber, fluororubber and thermoplastic elastomer. The manufacturing method of the pneumatic tire in any one.   7. The laminate sheet according to claim 1, wherein one or a plurality of the laminate sheets are used, and both ends of the laminate sheet are lap-spliced in the case of a single sheet and in the case of a plurality of sheets. The manufacturing method of the pneumatic tire in any one.

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