JP2000272023A - Production of pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a specified forming method for a splice which can simplify a molding process and does not deteriorate the durability of a splice part in joining tire member rubber, a different kind of elastomer incapable of direct vulcanization-adhesion, and an adhesive rubber. SOLUTION: In a pneumatic tire in which tire member rubber and a different kind of elastomer material A are adhered to a tire member through an adhesive rubber composition B, sheet-shaped A and B are shifted at a distance of the molded splice length (a) of A or above and laminated stepwise in the order of B/A/B or B/A, the laminate is wound onto a molding drum, and the splices A, B are formed individually and substantially simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a pneumatic tire, and more particularly, to a different kind of elastomeric material which cannot be directly vulcanized and bonded to rubber of a tire member (particularly, hydrogenated NBR is coated with zinc methacrylate and an organic peroxide). The present invention relates to a pneumatic tire manufacturing method capable of manufacturing a high-performance tire by specifying a splice forming method of a high-hardness material containing an oxide) and an adhesive rubber (tie rubber) to a specific method.

[0002]

2. Description of the Related Art A rubber composition obtained by blending zinc methacrylate and an organic peroxide in hydrogenated NBR (hereinafter referred to as "HNBR / zinc methacrylate composite") does not vulcanize and bond general-purpose rubber. Various bonding methods have been proposed (for example, JP-A-5-185805), and the present applicant has already proposed a method of directly vulcanizing and bonding with one layer of adhesive rubber (tie rubber) (JP-A-9-143306). And JP-A-9-295378 and JP-A-9-295379. This has made it possible to apply the HNBR / zinc methacrylate composite to tires. However, for example, when a sheet-like HNBR / zinc methacrylate composite is to be placed inside a tire, tie rubber, HNBR /
Laminating the zinc methacrylate composite and the tie rubber in this order is time-consuming and inefficient in production. Further, when a HNBR / zinc methacrylate composite and a tie rubber previously extruded in two or three layers at the same time are used, the production efficiency is high, but a structure in which a soft tie rubber is sandwiched between the splices of the HNBR / zinc methacrylate composite is obtained. To become
During running of the tire, there is a problem that stress is concentrated on the portion and the splice portion is broken.

[0003]

SUMMARY OF THE INVENTION Accordingly, in the present invention, a method for forming a splice of a dissimilar elastomer material and an adhesive rubber which cannot be directly vulcanized and adhered to a rubber of a tire member is specified, whereby a complicated molding process is performed. It is an object of the present invention to provide some pneumatic tire manufacturing methods capable of manufacturing a high-performance tire without deteriorating the durability of a splice portion.

[0004]

According to the present invention, a pneumatic tire obtained by adhering a different kind of elastomer material A, which cannot be directly vulcanized and bonded to a tire member rubber, to the tire member via an adhesive rubber composition B. In, the sheet-like A and B,
B / A / B shifted by more than the forming splice length (a) of A
And a method of manufacturing a pneumatic tire, wherein the laminate is wound around a forming drum to form splices A and B independently and substantially simultaneously.

Further, according to the present invention, in a pneumatic tire formed by bonding a different kind of elastomer material A which cannot be directly vulcanized and bonded to a tire member rubber to a tire member via an adhesive rubber composition B, A and B are staggered in the order of B / A with a shift of the forming splice length (a) of A or more, and this laminate is wound around a forming drum to splice the A and B splices individually and substantially. At the same time,
In addition, a method for manufacturing a pneumatic tire, in which the member is disposed on the innermost surface of the tire, is provided.

Further, according to the present invention, in a pneumatic tire obtained by bonding a different kind of elastomer material A which cannot be directly vulcanized and bonded to a tire member rubber to a tire member via an adhesive rubber composition B, , A are provided in a two-layered annular shape such that the inner side of the tire is inserted into a forming drum, and the innermost member of the tire is formed.

Further, in the present invention, A and B are wrapped in a pneumatic tire obtained by adhering a tire member rubber and a non-vulcanizable dissimilar elastomer material A to a tire member via an adhesive rubber composition B. Thus, a method for manufacturing a pneumatic tire is provided in which the simultaneously extruded sheets are wound at least two times or more around a forming drum to form a tire member.

Further, in the present invention, the different elastomeric material may be an ethylenically unsaturated nitrile-conjugated diene-based highly saturated rubber having a conjugated diene unit content of 30% or less.
A method for producing the pneumatic tire is provided, which is a rubber composition which is a rubber composition which is mixed with 0 to 120 parts by weight of zinc methacrylate based on 100 parts by weight of rubber containing 0 part by weight or more and crosslinked with an organic peroxide.

Further, in the present invention, the adhesive rubber composition comprises at least one diene rubber selected from natural rubber, polyisoprene rubber, polybutadiene rubber, conjugated diene-aromatic vinyl copolymer rubber, and nitrile rubber. A rubber composition comprising 5-80 parts by weight of an aromatic petroleum resin having an average molecular weight of 300-1500, a softening point of 50-160 ° C., and an iodine adsorption amount of 20 g / 100 g or more, in a total of 100 parts by weight of rubber. A method for producing the pneumatic tire having a thickness of 0.1 mm to 2.0 mm is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As a heterogeneous elastomer material A which cannot be directly vulcanized and bonded to a tire member to which the method of forming a splice according to the present invention can be effectively applied, for example, the above-described HNBR / zinc methacrylate composite is used. This H
The NBR / zinc methacrylate composite contains an ethylenically unsaturated nitrile-containing conjugated diene unit having a content of 30% or less.
Total 10 containing at least 40 parts by weight of a conjugated diene-based highly saturated rubber
The rubber composition is obtained by mixing 0 to 120 parts by weight of zinc methacrylate with respect to 0 parts by weight and crosslinking with an organic peroxide.

As the above-mentioned organic peroxide, those used in the ordinary peroxide vulcanization of rubber can be used. For example, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide,
Benzoyl peroxide, 2,5-dimethyl-2,5
-(T-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-mono (t-butylperoxy) hexane, α, α'-bis (t-butylperoxy-m-isopropyl) benzene and the like.
One or more of these organic peroxides are used, and it is desirable to add 0.2 to 10 parts by weight, preferably 0.2 to 6 parts by weight, per 100 parts by weight of rubber.

The HNBR / zinc methacrylate composite contains other fillers such as carbon black, silica,
Calcium carbonate, talc, etc., triallyl isocyanurate, higher esters of methacrylic acid, diallyl phthalate, m-phenylene bismaleimide, 1,2-
A co-crosslinking agent such as polybutadiene, and other plasticizers, antioxidants, stabilizers, adhesives, resins, processing aids, and colorants commonly used in the rubber industry may be appropriately compounded.

As the HNBR / zinc methacrylate composite, in addition to a rubber composition obtained by mixing zinc methacrylate with hydrogenated NBR, zinc compounds such as zinc oxide and zinc carbonate are first blended with hydrogenated NBR and sufficiently dispersed. After that, methacrylic acid may be mixed or absorbed to form zinc methacrylate in the polymer, and this method is preferred because a very good dispersion of zinc methacrylate is obtained. Further, a composition in which zinc methacrylate and a zinc compound are dispersed in hydrogenated NBR in advance may be used. This is a “ZSC” (trade name) series manufactured by Zeon Corporation, for example, ZSC2295, ZSC2295N, ZSC239.
5, ZSC2298 and the like.

The adhesive rubber composition to which the method for forming a splice according to the present invention can be effectively applied is at least one selected from natural rubber, polyisoprene rubber, polybutadiene rubber, and conjugated diene-aromatic vinyl copolymer rubber. One kind of diene rubber and nitrile rubber total 1
In 100 parts by weight, an average molecular weight of 300 to 1500 and a softening point of 5
A rubber composition containing 5-80 parts by weight of an aromatic petroleum resin having an iodine adsorption amount of 20 g / 100 g or more at 0 to 160 ° C.

[0015] If the amount of the aromatic petroleum resin is less than 5 parts by weight, the adhesive strength is reduced, and if it is more than 80 parts by weight, heat generation is large. It is not preferable to use a compounding amount other than the above. The mixing ratio (weight ratio) of the diene rubber and the nitrile rubber is preferably from 10:90 to 90:10 from the viewpoint of adhesive strength. The thickness of the adhesive rubber layer is 0.1
２．０2.0 mm, more preferably 0.2〜
0.8 mm. If this thickness is less than 0.1 mm, the adhesive rubber layer will be cut during production or processing will be difficult,
On the other hand, when the thickness is more than 2.0 mm, the uniformity of the tire is deteriorated and troubles such as air retention are more likely to occur.

The adhesive rubber layer may further comprise at least one selected from higher esters of methacrylic acid, triallyl isocyanurate, metal salts of methacrylic acid or acrylic acid, diallyl phthalate, and 1,2-polybutadiene.
It is more preferred to include a co-crosslinking agent and to crosslink with an organic peroxide. Further, in addition to the aromatic petroleum resin, a compounding agent generally mixed with rubber, for example, a filler such as carbon black, silica, talc, etc. An inhibitor, a plasticizer, a processing aid, a resin, an adhesive, a crosslinking aid, a vulcanization accelerator, a tackifier, and the like may be appropriately compounded.

In the method for manufacturing a pneumatic tire according to the present invention, a first method for producing a sheet in which the HNBR / zinc methacrylate composite and an adhesive rubber layer are laminated is as follows: HNBR / methacryl cut into a required length first. As shown in FIG. 1, the zinc oxide composite and the adhesive rubber layer are displaced by a splice amount a or more and laminated in a stepwise manner, and then wrapped around the drum so that the member closest to the drum comes to the front as shown in FIG. ,
This is a method in which the HNBR / zinc methacrylate composite and the splice of the adhesive rubber layer are formed substantially simultaneously. Also, H
When the NBR / zinc methacrylate composite is used for the innermost part (inner liner part) and the outermost part (tread part or side part) of the tire, as shown in FIG. 3, HNBR / methacrylic acid is used. The splice amount of the two layers of the zinc composite-adhesive rubber layer may be shifted by a or more, and the adhesive rubber layer may be wound around a drum so as to come to the tire side so that the two splices are formed substantially simultaneously.

The lamination of these members is performed during the cycle of the tire molding process, immediately before the supply of the material to the molding machine, and at the time of molding other members of the tire (at the time of laminating a tread, winding up a carcass end, laminating a belt layer, etc.). It is preferable to carry out simultaneously. The thickness of the adhesive rubber layer is 0.1 mm to 2.0 mm
And If it is too thin, it is impossible to mold, and if it is too thick, the step will increase and the uniformity of the tire will deteriorate,
Failures such as air retention are more likely to occur, which is not preferable.

As shown in FIG. 4, the second method of the present invention is a method in which the HNBR / zinc methacrylate composite and the adhesive rubber are simultaneously extruded in an annular shape and inserted into a drum. This method is applied only to a member that is first inserted into the drum, such as an inner liner. According to this method, since there is no need to form a splice portion, the HN
The BR / zinc methacrylate composite and the adhesive rubber layer can be laminated very uniformly.

As shown in FIG. 5, the third method of the present invention is a method of winding a material obtained by simultaneously extruding the HNBR / zinc methacrylate composite and the adhesive rubber layer two or more times. According to this method, even if the adhesive rubber layer is sandwiched between the HNBR / zinc methacrylate composite, the stress is dispersed at the splice portion, and thus the durability is not impaired, which is effective.

According to any of the above methods, the durability of the HNBR / zinc methacrylate composite portion can be greatly improved without forming a splice shape serving as a fracture starting point. In addition, since two or three splices can be performed simultaneously, compared to the conventional method in which the adhesive rubber layer and the HNBR / zinc methacrylate composite layer are separately wound around a drum,
Significantly reduces molding time. Furthermore, since the respective splices are independent, the adhesive rubber is not inserted between the splices of the HNBR / zinc methacrylate composite, so that the durability is not impaired. The pre-assembly of the adhesive rubber and the HNBR / zinc methacrylate composite does not affect the molding time of the tire if the molding of other components is basically performed during the cycle at the material supply device (servicer) of the tire molding machine. Is more preferable. Further, in the second method of extruding in a ring shape, the member can be formed by the extrusion step, so that the efficiency is further improved. The third method is more effective because the innermost member does not need to have a three-layer structure.

[0022]

EXAMPLES The present invention will be further described with reference to the following examples, but it goes without saying that the scope of the present invention is not limited to these examples.

In the following examples, steps up to the production of a green tire using the molding method of the present invention for forming an inner liner, a carcass cord and a run flat reinforcing liner will be described. The following Table 1 shows the composition of the HNBR / zinc methacrylate composite (formulations 1 to 3) and the adhesive rubber (formulation 4) used in each of the above tire members. The tire sizes shown in the following examples were all 185 / 65R14.

[0024]

[Table 1]

Example 1 (Molding method 1 was used to produce an inner liner) As shown in FIG. 3, an inner liner having a thickness of 0.7 mm (formulation 1) and an adhesive rubber having a thickness of 0.5 mm (formulation 4) Is cut into lengths each corresponding to one tire by a material supply device of a tire molding machine, and these are shifted by 50 mm and laminated.
Crimping was performed with a sponge roll. The laminated sheet was wound around a drum, and the inner liner layer of Formulation 1 and the adhesive rubber layer of Formulation 4 were spliced simultaneously. Next, wrap the carcass, drive in the bead and turn up,
A green tire was completed by laminating the belt layer and the cap tread.

Example 2 (Molding method 2 was used to produce the inner liner) As shown in FIG. 4, concentric circles having a thickness of 0.7 mm and a thickness of 0.5 mm were applied to the inner liner of Formula 1 and the adhesive rubber of Formula 4 respectively. It was simultaneously extruded in a ring shape to form a two-layered ring shape with the inner liner layer (formulation 1) inside and the adhesive rubber layer outside. This was cut to the width of one tire and inserted into the drum. Next, a carcass was wound around, a bead was driven in to turn up, a sidewall, a belt layer, and a cap tread were bonded to complete a green tire.

Example 3 (Molding method 3 was used for producing the inner liner) As shown in FIG.
Simultaneously extrude each adhesive rubber to a thickness of 0.5 mm,
It was made into a two-layer sheet. This sheet was wrapped twice so that the inner liner of Formulation 1 was on the drum side, and the members were cut on the drum. Then, wrap the carcass,
I hit a bead and turned up, the sidewall,
A green tire was completed by laminating the belt layer and the cap tread.

Example 4 (Molding method 1 was used to produce a carcass coat) As shown in FIG. 6, a polyester cord (1650) was used.
dTex × 2) was coated with a 1.2 mm thick carcass coat of Formula 2 to prepare a carcass. This carcass and a sheet of adhesive rubber (composition 4) having a thickness of 0.5 mm are cut into a length for one tire by a material supply device of a tire forming machine, and are cut into an adhesive rubber (composition 4) / carcass / adhesion. The rubber (formulation 4) was laminated stepwise with a displacement of 50 mm.
The laminate was wound around a forming drum after the inner liner, and the carcass and the adhesive rubber layer (formulation 4) were spliced at the same time. Next, a bead was driven in to make a turn-up, and a sidewall, a belt layer, and a cap tread were attached to complete a green tire.

Example 5 (Molding method 1 was used to produce a run flat reinforcing liner and inner liner) As shown in FIG. 7, an inner liner of Formulation 1 was cut into one tire in a material feeder of a molding machine. Then, a reinforcing liner of Formulation 3 extruded into a crescent shape was attached by shifting by 50 mm to form an integral member of the inner liner and the reinforcing liner. 0.5mm thick, shifted by 50mm with this integral member
Was bonded together (formulation 4). This laminate was wound around a forming drum with the inner liner side (formulation 1) as the drum side, and the inner liner, the reinforcing liner, and the adhesive rubber layer were simultaneously spliced. Next, a carcass was wound around, a bead was driven in to turn up, a sidewall, a belt layer, and a cap tread were bonded to complete a green tire.

[0030]

As can be seen from the above embodiment, the method of forming a splice of an adhesive rubber and a dissimilar elastomer material that cannot be directly vulcanized and adhered to a tire member rubber according to the present invention allows complicated molding. A high-performance tire can be manufactured without going through the steps and without impairing the durability of the splice.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a laminated structure in which three layers of an adhesive rubber layer / HNBR / zinc methacrylate composite layer / adhesive rubber layer are each laminated with a splice width a or more.

FIG. 2 is a cross-sectional view showing a state of a splice portion of each layer when an integrated member having a laminated structure shown in FIG. 1 is wound around a drum.

FIG. 3 is a diagram showing a state of bonding two layers of an HNBR / zinc methacrylate composite layer / adhesive rubber layer and a state of a splice when this is wound around a drum.

FIG. 4 is a diagram showing a concentric annular laminated structure of an HNBR / zinc methacrylate composite layer / adhesive rubber layer and an operation for inserting the laminated structure into a drum.

FIG. 5 is a diagram showing a state of bonding two layers of an HNBR / zinc methacrylate composite layer / adhesive rubber layer and a state of a splice when this is wound around a drum two or more times.

FIG. 6 is a diagram showing a state of bonding three layers of an adhesive rubber layer / HNBR / carcass coat layer of zinc methacrylate composite / adhesive rubber layer, and a state of a splice when this is wound around a drum.

FIG. 7 shows a three-layer bonding state of an inner liner layer of a HNBR / zinc methacrylate composite / a crescent-shaped reinforcing liner layer of a HNBR / zinc methacrylate composite / adhesive rubber layer, and a splice when this is wound around a drum. It is a figure showing the state of a part.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 9/00 C08L 9/00 // B29L 30:00 F term (reference) 4F072 AD02 AE02 AF17 AF23 AG16 AK05 AK11 AL18 4F207 AA20 AA22 AA45 AA46 AG03 AH20 KA01 KA17 KK82 4F212 AA20 AA22 AA45 AA46 AG03 AH20 VA02 VA10 VC02 VD20 VK03 VL07 4J002 AC011 AC031 AC061 AC071 AC111 AE052 EG046 EK037 EK047 FD010 FD020 FD010 FD020

Claims (6)

[Claims] 1. A pneumatic tire obtained by bonding a different kind of elastomer material A, which cannot be directly vulcanized and bonded to a tire member rubber, to a tire member via an adhesive rubber composition B,
The sheets A and B are laminated in a stepwise manner in the order of B / A / B with a shift of the forming splice length (a) of A or more, and this laminate is wound around a forming drum to splice the A and B respectively. A method for manufacturing a pneumatic tire, wherein the method is formed independently and substantially simultaneously. 2. A pneumatic tire obtained by adhering a dissimilar elastomer material A, which cannot be directly vulcanized and bonded to a tire member rubber, to a tire member via an adhesive rubber composition B,
The sheets A and B are laminated stepwise in the order of B / A with a shift of the forming splice length (a) of A or more, and this laminate is wound around a forming drum to separate the splices of A and B individually and separately. A method for manufacturing a pneumatic tire, comprising forming the member substantially simultaneously and disposing the member on the innermost surface of the tire. 3. A pneumatic tire obtained by bonding a different kind of elastomer material A, which cannot be directly vulcanized and bonded to a tire member rubber, to a tire member via an adhesive rubber composition B,
A method for manufacturing a pneumatic tire, characterized in that A and B are extruded into a two-layered annular shape such that A is on the inside, and this is inserted into a forming drum to form an innermost member of the tire. 4. A pneumatic tire obtained by adhering a dissimilar elastomer material A, which cannot be directly vulcanized and bonded to a tire member rubber, to the tire member via an adhesive rubber composition B,
A method for manufacturing a pneumatic tire, characterized in that a sheet extruded simultaneously so as to enclose A and B is wound at least twice around a forming drum to form a tire member. 5. The methacrylic rubber based on 100 parts by weight of a total of 100 parts by weight of a rubber containing 40% by weight or more of an ethylenically unsaturated nitrile-conjugated diene-based highly-saturated rubber having a conjugated diene unit content of 30% or less. Zinc acid 0-1
The rubber composition according to any one of claims 1 to 4, wherein the rubber composition is 20 parts by weight and is crosslinked with an organic peroxide.
13. The method for producing a pneumatic tire according to item 13. 6. The adhesive rubber composition according to claim 1, wherein a total of 100 weight parts of at least one diene rubber and a nitrile rubber selected from natural rubber, polyisoprene rubber, polybutadiene rubber, conjugated diene-aromatic vinyl copolymer rubber. In parts, average molecular weight is 300 to 1500, and softening point is 50 to 160.
C., a rubber composition containing 5 to 80 parts by weight of an aromatic petroleum resin having an iodine adsorption amount of 20 g / 100 g or more, and having a thickness of 0.1 mm to 2.0 mm. A method for manufacturing the pneumatic tire according to claim 5.