JPH08112110A - Bonding method between instep cover of shoe and lower peripheral rubber tape - Google Patents

Abstract

PURPOSE: To stabilize the bonding force by mixing a natural rubber kneaded material, polychloroprence rubber kneaded material, sulfur, zinc, and a solvent for obtaining a solution of a specific viscosity, and by applying this solution to the lower periphery of the instep cover that has been surface-treated by polytetrafluoroethylene for heating, and by pressedly vulcanizing an unvulcanized lower peripheral rubber tape. CONSTITUTION: When a surface-treated instep cover of a shoe and a lower peripheral rubber tape are bonded by polytetrafluoroethylene, a natural rubber kneaded material is obtained by natural rubber and a compounding agent not including sulfur. A polychloroprene rubber kneaded material is obtained both by polychloroprene rubber whose crystallization is large when the polymerization temperature is 20 deg.C or less, and by a rubber compounding agent not including zinc oxide. A natural rubber kneaded material and a polychloroprene rubber kneaded material are put into a solvent inside a vessel and are dissolved so that 50 to 70 parts by weight of a solid matter can be obtained. Sulfur and zinc oxide and a solvent are added to this solution so that the viscosity becomes 2000 to 10000 cp. The solution is applied to the lower periphery of the instep cover and is heated, and an unvulcanized lower peripheral rubber tape is pressedly brought into contact with the applied surface, and is vulcanized by hot air.

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, a shoe upper having a surface treated with a synthetic resin such as silicone has been proposed and partially put into practical use, but it has not been sufficient yet. However, very recently, an instep with a polytetrafluoroethylene surface treatment 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, in order to improve the adhesion between the instep and the unvulcanized rubber tape, 2. Three methods have been proposed.

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 solid content is adjusted to 20 to 30% and the viscosity measured by a Brookfield viscometer at a temperature of 20 ° C. using a No. 5 rotor at a rotational speed of 20 RPM is 8000 to 12.
It was adjusted to be 000 centipoise.

[0007] To this one solution, that is, 100 parts by weight of the former solution, was added 5 parts by weight of thiophospholic acid tris (P-isocyanate phenyl ester) having a solid content of 20%, and the solution was suspended in the last shell. After being applied to the lower peripheral portion once or twice, another solution, that is, 100 parts by weight of the latter solution, is applied to 100 parts by weight of the latter solution of thiophosphalic acid tris (P-).
5 parts by weight of isocyanate phenyl ester),
The coated surface is further coated and heated in hot air at a temperature of 40 ° C. for 3 minutes, the surfaces of the unvulcanized rubber tape activated by the solvent are overlapped, and the mixture is allowed to stand for 60 minutes in hot air at a temperature of 130 ° C. It was sulfur.

[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]

The present invention includes the following (a)-
(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 natural rubber kneaded product obtained in step (a) and the polychloroprene rubber kneaded product obtained in step (b) are mixed in a solvent in the same container so that the solid content is 50 to 70 parts by weight. And stir with cooling until homogeneously dissolved. (D) Sulfur and zinc oxide were added to the solution obtained in the step (c), and the mixture was stirred while cooling, and the solvent was added. The mixture was rotated by a Brookfield viscometer at 20 ° C. using a NO.5 rotor and rotated. Viscosity measured at several 20 RPM is 2000-1
Stir to reach 0000 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. In the present invention, the stirring time in the step (c) is 13 to 15
The second characteristic is that it is time. Furthermore, the present invention has a third feature that the cooling temperature in the step (c) and the step (d) is 30 to 40 ° C.

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 amount of 0 to 70 parts by weight is for the rubber kneaded material to be uniformly dispersed in the solvent to form a good solution. If it is less than 50 parts by weight, it is difficult to dissolve due to insufficient shearing during stirring,
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 are added to the solution obtained in step (c) as it is, that is, as a powder. However, it is usually added as a masterbatch so that it can be dissolved quickly and completely.

Stirring while cooling is continued for 1 to 2 hours, and the viscosity is the easiest to use as a solvent and the performance is most exerted, that is, at 20 ° C. by a Brookfield viscometer.
Using a No. 5 rotor, the viscosity measured at 20 RPM is 2000-10000 centipoise. In such a case, the state of having good permeability and anchoring property to the surface to be bonded is obtained. If it is 2000 to 6000 centipoise, it will be in a better state, and the solid content at this time will be 30 to 50.
% 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 was 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: Triol = 142.4: 149: 250
The mixture was placed in a container in a weight ratio of, cooled from the outer peripheral surface of the container, kept at 30 to 40 ° C. and stirred for about 15 hours. After the rubber kneaded product is uniformly dissolved in the toluene, 5% of sulfur and zinc white is added.
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.
Stir for 0 minutes. The solid content at this time was about 55%.

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%, the measured viscosity was 3500 centipoise. To this solution, 5 parts by weight of thiophospholic acid tris (P-isocyanate phenyl ester) having a solid content of 20% and a viscosity of 50 centipoise was added, and the solution was applied to the lower instep rim surface-treated with polytetrafluoroethylene. It was heated in hot air at a temperature of 70 ° C. for 7 minutes and baked.

According to Table 3, kneading was performed with 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, kneading is performed by a roll machine and aged to obtain 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 thiophosporic acid tris (P-isocyanate phenyl ester) having a solid content of 20% and a viscosity of 50 centipoise was added, and the former solution was first applied to the lower surface of the same instep as above. Then, the latter solution is further applied to the coated surface, unvulcanized rubber tape whose surface has been activated with toluol is overlapped and pressed, placed in an apparatus at a temperature of 130 ° C., and left standing for 60 minutes for vulcanization. The process is complete. This was used as a comparative example. The materials obtained by the two adhesion methods are compared in adhesion property by the peeling test method of JIS K6256, and shown in Table 6.

[0033]

[Table 6]

Claims (4)

[Claims] 1. A method for adhering a shoe upper cover surface-treated with polytetrafluoroethylene and a lower peripheral edge rubber tape, 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 natural rubber kneaded product obtained in the step (a) and the polychloroprene rubber kneaded product obtained in the step (b) are put in a solvent in the same container so that the solid content is 50 to 70 parts by weight, While cooling, stir until homogeneously dissolved. (D) Sulfur and zinc oxide were added to the solution obtained in the step (c), and the mixture was stirred while cooling, and the solvent was added. The mixture was rotated by a Brookfield viscometer at 20 ° C. using a NO.5 rotor and rotated. Viscosity measured at several 20 RPM is 2000-1
Stir to reach 0000 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.
The method for adhering the shoe upper and the lower peripheral edge rubber tape according to claim 1, which is 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.