KR101374924B1 - Cap Ply for Radial Tire and Preparation Method Thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap ply for a radial tire in which a conventional nylon 66 textile cord is replaced with a nylon 66 film, and a method of manufacturing the same. A cap ply for a radial tire that can maintain shape stability can be provided.

Description

Cap ply for radial tire and preparation method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap ply for a radial tire and a method of manufacturing the same. More specifically, by processing and applying a nylon 66 film instead of a conventional nylon 66 textile cord used as a cap ply, productivity is improved and fuel economy of a tire is increased. The present invention relates to a cap ply for a radial tire capable of improving performance and a method of manufacturing the same.

As one of the methods for providing radial tire safety, a method of applying cap plies to tires is widely used. In particular, in recent years, tires using such cap plies have become commonplace. Referring to Figure 1, the cap ply (4) is to maintain the shape stability of the tire by continuously arranging the fiber cord in the circumferential direction of the tire between the bottom of the tire tread (1) and the steel cord for reinforcing the belt (5) In particular, it is generally reinforced using materials exhibiting heat shrinkage at high temperatures.

Radial tires build the market for bias tires, and polyester textile cords are used as carcasses for radial tires, and nylon 66 textile cords are applied to cap fly materials to improve tire performance. In the case of the textile code used in this way, it can be manufactured into a textile code only through several processes. For example, in the case of nylon textile cords, the raw material chips are dried, spun and then stretched, and the yarn thus obtained is subjected to yarn weaving through a weaving machine and weaving. The woven fabric thus passed is passed through a dipping liquid and subjected to a heat treatment at a predetermined temperature range to obtain a finished nylon 66 textile cord. As such, applying the nylon 66 textile cord to the cap ply requires a complicated manufacturing process, resulting in an increase in manufacturing cost. Moreover, rubber is added to ensure that the fabric adheres well to the tire rubber to increase the overall weight of the tire.

The present invention is to overcome the above-mentioned problems of the prior art, an object of the present invention is to provide a cap ply consisting of a nylon film for applying to the cap ply (belt reinforcement layer) of a pneumatic radial tire for passenger cars and a method of manufacturing the same. will be.

One aspect of the present invention for achieving the above object is a cap fly for a radial tire, consisting of a biaxially stretched nylon film having a thickness of 0.1 to 1.0mm made of nylon, and comprises a plurality of perforations, The present invention relates to a cap ply for radial tires, which is dipped by an adhesive resin and a resorcinol formaldehyde latex dipping liquid.

Another aspect of the present invention for achieving the above object is the step of extruding a nylon film having a thickness of 0.1 to 1.0mm through biaxial stretching;

Perforating the extruded nylon film into a predetermined shape using a perforation facility;

Dipping the perforated nylon film into adhesive resin and resorcinol formaldehyde latex dipping solution;

It relates to a method for producing a cap ply comprising the step of heat-treating the dipped nylon film at a temperature of 180 ℃ to 250 ℃.

According to the present invention, the manufacturing process of the reinforcing material is simplified than when applying the existing nylon 66 textile cord, and the rolling process and the cutting process are not required in the tire manufacturing process, thereby improving productivity and price competitiveness of the product.

In addition, the tire to which the film cord of the present invention is applied can reduce the thickness of the cap ply layer, thereby making it possible to reduce the weight of the tire, and further, to provide an effect of significantly improving fuel efficiency by reducing rolling resistance.

1 is a schematic cross-sectional view of a general radial tire.
2 is a schematic diagram of a nylon film perforated into a grid shape constituting the cap ply of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in more detail the present invention.

The cap ply for a radial tire of one embodiment of the present invention is composed of a biaxially stretched nylon film having a thickness of 0.1 to 1.0 mm based on nylon, includes a plurality of perforations, and an adhesive resin and resorcinol formaldehyde. It is characterized in that the dipping treatment by a latex dipping liquid. The nylon film can be applied as a cap ply of a radial tire for a passenger car in a molding process in the same manner as a conventional method.

The biaxially stretched nylon film that satisfies the conditions of the present invention is, for example, biaxially stretched in the longitudinal direction (length direction) and the transverse direction (width direction) of an unstretched film obtained by melt extrusion of a polyamide-based resin chip as a raw material. After that, it can be manufactured by winding up in roll shape and heat-setting.

The cap ply of the present invention is a film manufactured by biaxial stretching after extrusion, or a grid-shaped nylon film manufactured by molding after extrusion, instead of textile cords manufactured through many existing complicated processes. It is applied as a cap ply to radial tires for passenger cars directly without the rolling process.

Since the nylon film can be used for the production of tires simply by extrusion and molding and then subjected to an adhesive treatment process, the nylon film is more economical and productivity than a cap ply using a conventional textile cord.

Although the form of the perforated part is not particularly limited, as shown in FIG. 2, for example, the perforated part may have a grid shape. In addition, the biaxially stretched nylon film includes a copolymer of nylon 6/66. Also here are nylon 46, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66/610 copolymer, nylon MXD6, nylon 6T, nylon 6 / 6T copolymer, nylon 66 / PP copolymer, nylon 66 / PPS copolymers and the like can be used together.

Another aspect of the present invention comprises the steps of extruding a nylon film having a thickness of 0.1 to 1.0mm through biaxial stretching; Perforating the extruded nylon film into a predetermined shape using a perforation facility; Dipping the perforated nylon film into adhesive resin and resorcinol formaldehyde latex dipping solution; And it relates to a method for producing a cap ply comprising the step of heat-treating the dipped nylon film at a temperature of 180 ℃ to 250 ℃.

In more detail with respect to this method, first, the raw material of the nylon 66 reinforcement used in the manufacture of the tire is specifically a copolymer consisting of 90 to 99.9wt% nylon 66 and 0.1 to 10wt% nylon 6 relative sulfuric acid viscosity Extruded into a film of 0.1 to 1.0 mm in thickness and 5 to 20 mm in width using a solid phase polymer chip to reach 3.0 to 3.5 levels (96% sulfuric acid solution). At this time, the extruder used in the manufacture of the film should be an extruder capable of biaxial stretching, and performs an appropriate level of biaxial stretching to extrude into a film of a desired thickness. The film produced should have a machine direction strength of 5.0 to 10.0 g / d.

In order to use the thus prepared film as a tire structure, the film must have adhesion to rubber. First, the film is perforated in a grid (lattice) form so that the film can be physically bonded to rubber. The perforation method can be drilled continuously using a kind of calendar, and the shape of the life preserver should be as long as possible. However, when slitting the film to less than 0.5 cm in width, it is not necessary to perforate.

The perforated portion of the perforated nylon film forms a rubber bridge (Rubber Bridge) inside the tire, thereby suppressing the occurrence and propagation of cracks can have a sufficient peel strength (Peel Strength).

Since the surface of the film thus processed may not yet have adhesive strength, it is possible to sufficiently maintain adhesion to rubber by performing a dipping using Resorcinol Formaldehyde Latex (“RFL”). Unlike the conventional RFL dipping liquid, since the dipping liquid used here must have sufficient adhesiveness with the compounding rubber, it may contain a terpene-based resin as the pressure-sensitive adhesive and may include various other pressure-sensitive adhesives.

The RFL dipping liquid not only has a high reactivity and adhesion to the nylon film, but also can be applied as a cap ply without increasing the thickness. Accordingly, it is possible to reduce the weight of the tire and improve the fuel economy of the vehicle, and to maintain the shape stability of the tire by minimizing the movement of the belt even during repeated deformation of the tire manufacturing process or the vehicle driving process.

The resorcinol-formalin-latex (RFL) -based adhesive may include a condensate of resorcinol and formaldehyde and a latex. The condensate of resorcinol and formaldehyde may be obtained by mixing the resorcinol and formaldehyde in a predetermined molar ratio and then condensation reaction.

The latex may be at least one mixture selected from the group consisting of natural rubber latex, styrene / butadiene rubber latex, acrylonitrile / butadiene rubber latex, chloroprene rubber latex and styrene / butadiene / vinylpyridine rubber latex. In addition, the dipping liquid further contains at least one additive such as a heat-resistant antioxidant, a heat stabilizer, an adhesion promoter, a surface tension modifier heat-resistant agent, an antifoaming agent, and a filler, together with a condensate and latex of resorcinol and formaldehyde. can do.

Examples of other usable pressure-sensitive adhesives for modifying adhesion with rubber may include rosin resins, terpene-phenol resins, aliphatic petroleum resins, aromatic petroleum resins, dicyclopentadiene petroleum resins, and the like.

The heat treatment is carried out at temperatures between 180 ° C. and 250 ° C. below the temperature applied for existing nylon 66 textile cords. If the temperature of the said heat processing is less than 180 degreeC, sufficient heat processing effect cannot be acquired. On the contrary, when the temperature of the heat setting treatment exceeds 250 ° C., the mechanical strength of the film tends to be weak, and the frequency of breakage during the process increases, which is not preferable.

The finished nylon film for cap ply has a strength of 5.0-10.0 g / d, and an axial dry heat shrinkage rate of 4.0-10.0%. Dry heat shrinkage was performed under conditions of 177 ° C x 2 minutes.

Since the cap ply of the present invention composed of a nylon film has adhesiveness, it can be directly applied in a tire forming step without a rolling step. Since weaving, rolling, and cutting processes are not needed like conventional textile tire cords, they are much more economical in the manufacturing process, and the thickness of the cap ply layer can be made thin, which is a great help to reduce the weight of the tire.

Hereinafter, the present invention will be described in detail with reference to Examples, and the present invention is not limited by the following Examples.

Example

A film having a thickness of about 0.5 mm by extruding and biaxially stretching a polymer obtained by copolymerizing a copolymer composed of 90 wt% nylon 66 and 10 wt% nylon 6 to have a relative sulfuric acid viscosity of 3.0 to 3.5 (96% sulfuric acid solution). Extruded. Subsequently, holes of 1 mm × 10 mm were punched at 1 mm intervals using a perforated calender.

17 parts by weight of resorcinol, 5 parts by weight of formaldehyde 37% aqueous solution, 5 parts by weight of 28% aqueous solution of ammonium hydroxide, 20 parts by weight of vinyl pyridine latex having a solid content of 40%, 85 parts by weight of water, 5 parts by weight of 5% sodium hydroxide solution. And a dipping liquid including 10 parts by weight of a terpene resin emulsion. Subsequently, a heat treatment was performed at 200 ° C. to obtain a film, and then applied as a cap ply of the tire by the same process as the existing process to prepare a test tire. The physical properties were evaluated in the following manner, and the results are shown in Table 1 below.

[Property evaluation method]

The 215/60 R15 V tires manufactured according to the Examples and Comparative Examples were mounted on a 2000cc class passenger car and the noise generated in the vehicle was measured while driving at a speed of 60 km / h. The steering stability and ride comfort were evaluated by experienced drivers on a test course in units of 5 out of 100 points.

Comparative Example

Except for using nylon 66 840D / 2 1 ply fiber cord as a cap ply, the tire was manufactured in the same manner as in Example 1, and the physical properties were evaluated in the same manner as in Example. Indicated.

Example Comparative Example Belt structure 1 x 2 (0.30) 1 x 2 (0.30) Bead 0.89 0.89 Steering stability 98 100 Ride comfort 101 100 Noise performance 98 100 Rotation resistance 7.9 7.7 weight 10.2Kg 10.5Kg

As can be seen from the test results of Table 1, the tire according to the present invention (Example 1) can be seen that the weight of the tire is reduced compared to the case of applying a conventional nylon fiber cord (Comparative Example 1), and thus rotation It can be seen that the resistance can be reduced. In addition, in the case of the present invention using a nylon film as a cap ply in terms of performance, it can be confirmed that the effect is excellent in terms of riding comfort, steering stability and noise reduction.

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims. .

1: tread 2: shoulder
3: Side Wall 4: CAP PLY
5: Belt 6: Body Ply
7: Inner Liner 8: APEX
9: BEAD

Claims (7)

A cap ply for a radial tire, comprising a biaxially stretched nylon film having a thickness of 0.1 to 1.0 mm, made of nylon, and comprising a plurality of grid-shaped perforations, and an adhesive resin and a resorcinol formaldehyde latex dipping liquid As dipped by
The nylon film is formed by using a solid-phase polymerized chip having a copolymer of 90 to 99.9 wt% nylon 66 and 0.1 to 10 wt% nylon 6 to have a relative sulfuric acid viscosity of 3.0 to 3.5 (96% sulfuric acid solution). Cap fly for a radial tire, characterized in that produced by extrusion into a film of 0.1 to 1.0mm, width 5 to 20mm.
delete delete Extruding a nylon film having a thickness of 0.1 to 1.0 mm through biaxial stretching;
Perforating the extruded nylon film into a predetermined shape using a perforation facility;
Dipping the perforated nylon film into adhesive resin and resorcinol formaldehyde latex dipping solution;
Heat-treating the dipped nylon film at a temperature of 180 ° C. to 250 ° C.,
In the nylon film extrusion step, a copolymer of 90 to 99.9 wt% nylon 66 and 0.1 to 10 wt% nylon 6 is polymerized using a solid-phase polymerized chip to have a relative sulfuric acid viscosity of 3.0 to 3.5 (96% solution of sulfuric acid). , 0.1 to 1.0mm thick, the step of extruding a film of 5 to 20mm in width, the method for producing a code for a cap fly ply.
delete The method according to claim 4, wherein the extruded film is biaxially stretched so that the machine direction strength is 5.0 to 10.0 g / d.
The method of claim 4, wherein the perforating step comprises perforating the film in a grid form.

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