JP2652351B2 - Adhesion method between the shoe upper and the lower peripheral rubber tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding a shoe upper covered with polytetrafluoroethylene and a lower peripheral rubber tape.

[0002]

2. Description of the Related Art In recent years, in the upper of shoes, for example, the upper of cloth shoes, various improvements have been made to improve comfort such as breathability, texture and feel. . In addition, there is a tendency to design in accordance with the fashioning of clothing, that is, a so-called total look.

[0003] Shoes using the above-mentioned upper cover surely satisfy the demands of consumers and help to activate the shoe market, but they are insufficient in terms of water repellency and stain resistance. . In view of such circumstances, shoe uppers that have been surface-treated with a synthetic resin such as silicone have been proposed, and some have been put to practical use, but have not been said to be sufficient. Thus, very recently, a polytetrafluoroethylene surface-treated upper has been proposed.

[0004] The most recently developed upper cover is water repellent,
Although satisfactory results were obtained in both antifouling properties, it had a drawback that it was difficult to adhere to an unvulcanized rubber tape during the shoe manufacturing process. Conventionally, a few methods have been proposed to improve the adhesion between the upper and the unvulcanized rubber tape.

For example, polychloroprene rubber having a large crystallization at a polymerization temperature of 20 ° C. or less is kneaded while adding a rubber compounding agent containing white carbon as a main component, and the kneaded product is dissolved in a solvent to form one solution. Also, apart from the one solution, a natural rubber is kneaded while adding a vulcanizing agent and a rubber compounding agent containing calcium carbonate as a main component, and the kneaded product is dissolved in a solvent to form another solution.

[0006] These two solutions, considering adhesion,
The solids content was adjusted to 20 to 30%, and the Brookfield viscometer was used to measure No. 2 at a temperature of 20 ° C. The viscosity measured at 20 RPM using a 5-rotor is 8000 to
It had been adjusted to be 12,000 centipoise.

[0007] To 100 parts by weight of this one solution, that is, the former solution, 5 parts by weight of an organic solvent solution of thiophenoacidic tris (P-isocyanate phenyl ester) having a solid content of 20% is added and suspended in the last. After being applied once or twice to the lower edge of the upper shell, thiophenoacidic tris (P-isocyanate phenyl ester) having a solid content of 20% is added to another solution, that is, 100 parts by weight of the latter solution.
5 parts by weight of an organic solvent solution was added, and the solution was further coated on the coating surface, heated in hot air at a temperature of 40 ° C. for 3 minutes, and a surface of an unvulcanized rubber tape activated with a solvent was superposed, and the temperature was 130 ° C.
For 60 minutes in the hot air for vulcanization.

[0008]

SUMMARY OF THE INVENTION The conventional bonding method is as follows.
For the upper cover surface treated with polytetrafluoroethylene, the adhesive layer formed by the former solution in order to improve the anchoring effect on the surface, and the unvulcanized rubber lower peripheral tape Although the adhesive layer formed by the latter solution is in contact with each of the above-mentioned surfaces and tries to adhere,
Since the two solutions have different rubbers, there is concern that delamination may occur due to the history after bonding. An object of the present invention is to overcome the above problems.

[0009]

Means for Solving the Problems The present invention provides the following (a) to
(E) A method of bonding a shoe upper covered with polytetrafluoroethylene and a lower peripheral rubber tape, the method comprising the step of (e). (A) Kneading while adding a rubber compounding agent containing no sulfur to natural rubber to prepare a natural rubber kneaded product. (B) kneading a polychloroprene rubber having high crystallinity at a polymerization temperature of 20 ° C. or less while adding a rubber compounding agent containing no zinc oxide to prepare a kneaded product of polychloroprene rubber.

(C) The kneaded product of natural rubber obtained in step (a) and the kneaded product of polychloroprene rubber obtained in step (b) are mixed in a solvent in the same container so that the solid content is 50 to 70% by weight. And stir with cooling until homogeneously dissolved. (D) Sulfur and zinc oxide are added to the solution obtained in step (c), and the mixture is stirred while cooling, and a solvent is added. The viscosity measured at 20 RPM using a 5-rotor is 2000 to 2000.
Stir to 10,000 centipoise.

(E) The solution obtained in the step (d) is applied to the lower periphery of the upper shell surface-treated with polytetrafluoroethylene, heated, and the uncured solution activated with a solvent is applied to the coated surface. The first characteristic is that the peripheral rubber tape is pressed and vulcanized in hot air. The second feature of the present invention is that the stirring time in the step (c) is 13 to 15 hours. Further, the present invention is characterized in that the cooling temperature in the steps (c) and (d) is 30 to 40 ° C. as a third feature.

Further, the present invention is characterized in that the heating in the step (e) is performed in hot air at 40 to 70 ° C. for 3 to 10 minutes. In the step (a), natural rubber is used because the lower peripheral rubber tape is almost always made of natural rubber or a blend rubber thereof, and the affinity for the rubber is considered.

It is desirable to add 20 to 40 parts by weight of a filler such as calcium carbonate to 100 parts by weight of natural rubber in order to increase the affinity, that is, the adhesion. In the step (d), the polychloroprene rubber having a high crystallinity at a polymerization temperature of 20 ° C. or lower was used because it has good affinity for the upper surface treated with polytetrafluoroethylene and at the same time, This is because heat resistance is good at the time of the heat treatment after the two are pressure-bonded, and the adhesive surface is not opened due to stress or the like.

In the step (c), the blending ratio of the natural rubber mixture and the polychloroprene rubber kneaded material in a container in terms of pure rubber is usually 20 to 80 parts by weight for the former. In this range, the adhesive strength can be exerted in a well-balanced manner both on the upper and on the unvulcanized lower peripheral rubber tape. As the solvent, toluene having good solubility in polychloroprene rubber is used.

[0015] The solid content of the rubber kneaded material after the solution is
The reason for setting the amount to 0 to 70% by weight is to uniformly disperse the rubber kneaded material in the solvent and to produce a good solution.
If it exceeds 70% by weight, it becomes too viscous and cannot be stirred. In the stirring step, the kneaded product of polychloroprene rubber generates considerable heat in a normal method,
In the present invention, the reaction is performed while cooling the container so that the temperature is maintained at 30 to 40 ° C.

In this manner, gelation of the kneaded polychloroprene rubber is prevented, and the kneaded material can be uniformly dissolved in the solvent by continuing stirring for 13 to 15 hours. When the stirring time is set to 13 to 15 hours, it is possible to completely and completely dissolve. In the step (d), sulfur as a vulcanizing agent for natural rubber and zinc oxide as a vulcanizing agent for polychloroprene rubber may be added to the solution obtained in step (c) as it is, that is, as a powder. Good,
Usually, it is added as a master batch so that it can be dissolved quickly and completely.

Stirring while cooling is continued for another 1 to 2 hours, and the viscosity is most easily used as a solvent, and its performance is most easily exhibited, that is, NO. The viscosity measured at 20 RPM is 2,000 to 10,000 centipoise using a 5 rotor. In such a case, the state of having good permeability and anchoring property to the surface to be bonded is obtained. A better condition is obtained when the pressure is set to 2000 to 6000 centipoise, and the solid content at this time is 30 to 5 centipoise.
0% by weight.

In the step (e), the surface to which the solution is applied is heated in hot air at a temperature of 40 to 70 ° C. for 3 to 10 minutes so that a so-called seizure-like action is effected. The heating after the surfaces to be adhered is a vulcanization step, which is performed in hot air at about 130 ° C. for about 60 minutes. The lower peripheral rubber tape used in the present invention is mainly composed of natural rubber and kneaded with polybutadiene rubber, polyisoprene rubber, styrene / butadiene copolymer rubber and the like.

[0019]

The present invention relates to the above (a) step and (b)
Since the rubber kneaded material not containing the vulcanizing agent obtained in the step is cooled while being stirred in a solvent in a stirring step, the kneaded material itself is originally difficult to gel and hardly generates heat, as described above,
Even if some heat is generated, it is kept in a cooling state at all times, so that gelation is further prevented. Therefore, the stirring step is performed with the concentration of the kneaded material increased, and shearing is easily applied, and the stirring step can be performed over a long time, so that a more uniform solution can be obtained.

In addition, since the vulcanizing agent is added near the final step of the solution, gelation can be prevented more reliably, and when this is used as an adhesive, there is no variation and stable adhesive strength. Can be obtained.

[0021]

EXAMPLES Kneading is carried out by a roll machine according to Table 1, and after maturation, chips are formed.

[0022]

[Table 1]

According to Table 2, kneading is performed by a roll machine.
After ripening, make chips. Here, neoprene AD manufactured by Showa Neoprene Co., Ltd. is used as the polychloroprene rubber.

[0024]

[Table 2]

Chips obtained from Table 1: Chips obtained from Table 2: Toluol = 142.4: 149: 250
, And the mixture was cooled from the outer peripheral surface of the container and stirred at 30 to 40 ° C. for about 15 hours. After the rubber kneaded material is uniformly dissolved in toluene, sulfur and zinc white 5
Add 4 parts by weight and 10 parts by weight of 0% masterbatch, respectively, and continue cooling for 1 hour 3 hours as described above.
Stirred for 0 minutes. The solid content at this time was about 55% by weight.

At this time, 150 parts by weight of toluene was added, and the mixture was stirred for about 1 hour while cooling was continued. About 4 solids
At 3% by weight, the viscosity measured by the above method was 3500 centipoise. To this solution was added a thiophene maleic acid tris (P-) having a solid content of 20% and a viscosity of 50 centipoise.
5 isocyanate phenyl ester) in organic solvent
Parts by weight and applied to the lower edge of the upper shell surface-treated with polytetrafluoroethylene.
Heated for a minute and baked.

According to Table 3, kneading was carried out using a roll machine. The kneaded product was rolled by a calender, and an unvulcanized rubber tape was obtained through processes such as cutting. One surface of the tape is wiped with a toluene to almost evaporate and activate the solvent, contact the lower edge of the instep, press, place in a device at a temperature of 130 ° C., and stand for 60 minutes. The sulfurization process was completed.

[0028]

[Table 3]

This was used as the bonding method according to the method of the present invention.
On the other hand, according to Table 4, the mixture is kneaded by a roll machine and aged to form chips.

[0030]

[Table 4]

At the same time, kneading is performed according to Table 5 and the mixture is aged to form chips.

[0032]

[Table 5]

The chips obtained in Table 4 were dissolved in toluene to form a solution, and the chips obtained in Table 5 were dissolved in toluene to form a solution. The viscosity was adjusted to 10,000 centipoise by the above-mentioned measurement method. did.
To each of these solutions, 5 parts by weight of an organic solvent solution of thiophenoacidic tris (P-isocyanate phenyl ester) having a solid content of 20% and a viscosity of 50 centipoise was added. The solution is applied, and the latter solution is further applied to the applied surface, an unvulcanized rubber tape whose surface has been activated with toluene is superposed and pressed, placed in a device at a temperature of 130 ° C., and allowed to stand for 60 minutes. The vulcanization process was completed. This was used as a comparative example. The materials obtained by these two bonding methods were compared in terms of adhesion by a peeling test method of JIS K6256, and are shown in Table 6.

[0033]

[Table 6]

Claims (4)

(57) [Claims] 1. A method of bonding a shoe upper covered with polytetrafluoroethylene and a lower peripheral rubber tape, the method comprising the following steps (a) to (e): (A) Kneading while adding a rubber compounding agent containing no sulfur to natural rubber to prepare a natural rubber kneaded product. (B) Kneading a polychloroprene rubber having high crystallinity at a polymerization temperature of 20 ° C. or less while adding a rubber compounding agent containing no zinc oxide to prepare a kneaded product of polychloroprene rubber. (C) The kneaded product of natural rubber obtained in step (a) and the kneaded product of polychloroprene rubber obtained in step (b) are placed in a solvent in the same container so that the solid content is 50 to 70% by weight, With cooling, stir until homogeneously dissolved. (D) Sulfur and zinc oxide are added to the solution obtained in step (c), and the mixture is further stirred while cooling, and a solvent is added. The viscosity measured at 20 RPM using a 5-rotor is 2000 to 2000.
Stir to 10,000 centipoise. (E) coating and heating the solution obtained in the step (d) on the lower periphery of the upper shell surface-treated with polytetrafluoroethylene,
An unvulcanized lower-peripheral rubber tape activated with a solvent is pressed onto the coating surface and vulcanized in hot air. 2. The stirring time in the step (c) is 5-15.
2. The method according to claim 1, wherein the time is a time. 3. The method according to claim 1, wherein the cooling temperature in the step (c) and the step (d) is 30 to 40 ° C. 4. The heating time in the step (e) is from 40 to 7
The method for bonding a shoe upper to a lower peripheral rubber tape according to claim 1, which is performed in hot air at 0 ° C for 3 to 10 minutes.