KR101001003B1 - Shoes bonding process by atmospheric pressure plasma - Google Patents

Abstract

The present invention relates to a shoe bonding and cleaning process by using an atmospheric plasma to eliminate the use of a primer, a chemical, and also to reduce the use of a cleaning chemical. Washing for 10 seconds to 10 minutes with ozone water having a concentration of 0.01 to 30 ppm or a surfactant having a concentration of 0.0001 to 10 wt% → 10 in an aqueous solution having a concentration of 0.0001 to 10 wt% in the range of 0 to 80 ° C The process proceeds from second to 10 minutes, followed by washing → drying → plasma surface modification → application of an aqueous or solvent-based adhesive → drying → compression.

Description

SHOES BONDING PROCESS BY ATMOSPHERIC PRESSURE PLASMA}

The present invention relates to a shoe bonding method by an atmospheric plasma, and more particularly to a shoe bonding method by an atmospheric plasma to eliminate the use of a primer primer, and to reduce the use of cleaning chemicals.

There are serious environmental pollution and wastewater treatment problems that can occur in conventional organic solvent adhesives today.
As the environmental diversity of organic solvents used in adhesives and pretreatment processes is strengthened along with the diversity of materials, changes to environmentally friendly adhesives and adhesive processes are required. Furthermore, the types of adhesives are much more diverse than in the past. Making the process more difficult.

In this trend, the footwear industry needs to be converted to an eco-friendly adhesive process in recent years.

In order to escape from labor-intensive industry to high value-added industry, the Korean shoe industry is doing a lot of research on the high-quality parts and automation of manufacturing facilities. The development of aqueous primers and adhesives is also being activated for the purpose of cleaning.
Typical examples of automated production include mid-sole parts manufactured by injection molding.

However, in the shoe assembly line, the role of the adhesive still needs to be improved in terms of absolutely lower manufacturing costs and environmental friendliness.

The present bonding process is shown in Table 1.

[Table 1] Bonding process of shoe sole material

Kind of Sole Solvent Adhesive Processing Process Aqueous adhesive treatment process

Rubber
out-sole Rubber sole → roughing (sometimes not roughing) → Ultrasonic or high pressure spray chemical cleaning (sometimes not ultrasonic cleaning) → Fishery washing → Drying → Solvent primer treatment → Drying → Solvent adhesive coating → Drying → Pressing Rubber sole → roughing (sometimes not roughing) → Ultrasonic or high pressure spray chemical cleaning (sometimes not ultrasonic cleaning) → Fishery washing → Drying → Solvent type primer or aqueous primer treatment → Drying → Aqueous adhesive coating → Drying → crimp
Phylon
mid-sole
Phylon sole → Solvent cleaning → UV primer treatment and irradiation → Drying → Solvent adhesive application → Drying → Pressing Phylon sole → Solvent or water washing → Drying → UV primer treatment and irradiation → Drying → (Solvent-type or aqueous primer treatment) → Applying water-based adhesive → Drying → Pressing
PU mid-sole PU sole → Solvent cleaning → Drying → Solvent primer and aqueous primer treatment → Drying → Solvent adhesive → Drying → Pressing PU sole → Solvent cleaning → Drying → Solvent primer and aqueous primer treatment → Drying → Aqueous adhesive → Drying → Pressing

As can be seen in Table 1, the bonding process is very complicated and environmentally harmful substances are used in large quantities.
A technology that can block the use of toxic substances is a particularly attracting attention recently is the simplification of the adhesion process using plasma.

Plasma techniques are now widely used for the modification of printability, wettability, adhesion, bonding, biocompatibility, surface strengthening, etc. as surface-related properties.
Plasma technique is known to have excellent surface cleaning, etching and surface modification effects, and when it interacts with molecules on the surface of shoe-related polymer materials, it removes organic substances from the surface and after surface activation by inert gas plasma. Crosslinking reactions, surface molecular chemical structure rearrangements, and the like may occur. In the case of surface molecular chemical structure rearrangement, polar groups may be formed on the surface to increase surface energy, thereby causing interaction with other materials.
Since plasma technology is not required for organic solvents, it can be almost absolutely reduced when exposed to harmful substances when applied to the adhesion process of shoes, so it will be a very useful technique that can simultaneously reduce costs and create an environment-friendly working environment.
Although some shoe manufacturing plants have reviewed the plasma technique to date, it has been found that despite the excellent surface treatment effect, the low pressure / low temperature plasma technique failed to bond to the mass production system of shoes.
In other words, the low pressure / low temperature plasma process requires a vacuum and thus is not possible in a continuous process, which is pointed out as a big limitation in the application of mass production.
Therefore, in order to overcome this, application of atmospheric pressure plasma capable of continuous process is required. In this case, research on process conditions for each material is necessary because no research has been made to apply the adhesion pretreatment process of shoes.
In addition, since the shape of the shoe mid-sole and out-sole has a three-dimensional shape with height and curvature rather than a two-dimensional plane, a study of a three-dimensional plasma treatment technique is urgently needed.

Table 2 shows the adhesion process predicted when atmospheric cold plasma technology is applied to shoes.

[Table 2] Adhesion Process Using Atmospheric Pressure Plasma

Kind of Sole Solvent Adhesive Processing Process Aqueous adhesive treatment process
Rubber
out-sole
Rubber sole → Plasma active water cleaning → Drying → Plasma treatment → Solvent type adhesive → Drying → Pressing Rubber sole → Plasma active water washing → Drying → Plasma treatment → Aqueous adhesive → Drying → Pressing
Phylon
mid-sole
Phylon sole → Plasma active water washing → Drying → Plasma treatment → Solvent type adhesive → Drying → Pressing Phylon sole → plasma active water washing → drying → plasma treatment → aqueous adhesive → drying → compression
PU mid-sole PU sole → Solvent cleaning → Drying → Plasma treatment → Solvent type adhesive → Drying → Pressing PU sole → Solvent cleaning → Drying → Plasma treatment → Aqueous adhesive → Drying → Crimping

As shown in Table 2, several types of manual processes can be reduced to one-step automation, resulting in significant labor savings and improved productivity.
In addition, it is possible to lower the defective rate and improve the quality by controlling the standardized adhesive quality of the adhesive defect which occupies most of the shoe defects in terms of quality.
Therefore, manufacturing cost can be lowered through reduction of labor cost, productivity increase and quality improvement, which takes up a large part of shoe manufacturing cost, and it can secure competitiveness as a high quality product with excellent quality.
In addition, it does not use solvents harmful to the human body used in the pretreatment process of the bonding process, which makes the working environment pleasant, and does not generate any environmental pollutants.
In addition, by selecting shoes manufactured using a method that is more environmentally friendly and not harmful to human beings, the effect of pollutants on the human body can be greatly reduced.
The present invention is to study the applicability of the material for shoes using a room temperature / low pressure plasma device, and to utilize it to commercialize the related technology.

Low pressure plasma is easy to generate a plasma, but the cost of a vacuum chamber, an exhaust device, etc. to maintain a low pressure state is expensive, there is a limit to the mass processing due to the batch type (batch type) product input method.
On the other hand, since atmospheric plasma generates plasma at atmospheric pressure (760 Torr), an expensive vacuum system is not required, and a continuous process is possible, which has many advantages in mass production.

Hereinafter, the polymer material application of the plasma process will be described.

In general, since the temperature of ions and neutral particles in the plasma maintains a low temperature state, most polymers that are easily damaged by heat can be used as the substrate.
The overall surface modification field by the plasma process technology may include plasma cleaning, surface functionalization, and surface deposition.

Adhesion enhancement by plasma technology of polymer materials has already been reported in various literatures.
Interfacial adhesion in polymeric materials is advantageous when they are physically engaged with each other or have ionic, covalent, or secondary bonds due to the rough surface. In addition, it is advantageous when there is an electrostatic attraction due to the formation of an electric double layer at the interface and internal diffusion or thermodynamic adsorption depending on molecular weight or polarity, but most polymers are not well equipped with such an adhesive environment.
Therefore, it is preferable to introduce a functional group such as a hydroxyl group or a carbonyl group or a carboxyl group or an amino group to enable covalent or secondary bonding.
Halogen compounds are used in the footwear industry as a pretreatment process for the coating process, which can cause surface cracks, oxidation and deterioration in environmental problems or excessive use.

Accordingly, the present invention has been made to solve the above-mentioned problems according to the prior art, to provide a shoe adhesion method by an atmospheric pressure plasma to eliminate the use of a primer primer and to reduce the use of cleaning chemicals There is.

The characteristics of the shoe bonding and cleaning process by atmospheric pressure plasma to achieve the above object,

After the shoe material was put in, it was washed for 10 seconds to 10 minutes with ozone water having a concentration of 0.01 to 30 ppm or a surfactant having a concentration of 0.0001 to 10 wt% at a temperature of 0 to 80 ° C, and at a temperature of 0 to 80 ° C. After washing for 10 seconds to 10 minutes in an aqueous solution having a concentration of 0.0001 to 10 wt%, drying, plasma surface modification, coating with an aqueous adhesive or solvent-based adhesive, drying, and pressing are sequentially performed. Characterized in that made.

As described above, the shoe adhesion method by the atmospheric plasma according to the present invention has the effect of eliminating the use of a primer primer and reducing the use of a cleaning chemical.

In addition, the shoe adhesion method by the atmospheric pressure plasma according to the present invention has the effect of excellent adhesion than the existing without using the existing primer solvent, there is an advantage that can shorten the process.

Hereinafter, the preferred embodiment of the shoe bonding method by the atmospheric pressure plasma according to the present invention.

1 is a view schematically showing a first embodiment of the shoe bonding method by the atmospheric plasma according to the present invention, Figure 2 is a view schematically showing a second embodiment of the shoe bonding method by the atmospheric pressure plasma according to the present invention to be.

As shown in FIG. 1, the basic core of the shoe adhesion method by the atmospheric plasma of the first embodiment is to wash the ozone water or the surfactant, and to wash the fish and to modify the plasma surface.

And, as shown in Figure 2, the basic core of the shoe bonding method by the atmospheric pressure plasma of the second embodiment, the plasma active water after washing, and the plasma surface modification.

The overall process of the shoe bonding method by the atmospheric plasma of the first embodiment described above, after adding the shoe material, washing with ozone water or a surfactant, washing with hydroxyl, and then drying, plasma surface modification, aqueous Application | coating of an adhesive agent or a solvent-type adhesive agent, drying, and crimping | compression-bonding consist of sequentially progressing.

In addition, the whole process of the shoe bonding method by the atmospheric pressure plasma of 2nd Example mentioned above is a water-based adhesive agent or a solvent-type adhesive agent after putting in shoes material, wash | cleaning plasma active water, drying, and performing plasma surface modification. Applying, drying, and compressing consist of proceeding sequentially.
In the above, it is preferable to apply atmospheric pressure plasma or vacuum plasma to the plasma surface modification.
In addition, the working gas of the plasma surface modification is preferably made of one or more of air, nitrogen, oxygen, argon, CF ₄ , SF ₆ , C ₂ H ₂ , CH ₄ gas.

3 is a view showing the adhesion characteristics according to the presence or absence of the buffing rubber and the cleaning time of the fish in Experimental Example 1 of the first embodiment according to the present invention, the experimental conditions of Experimental Example 1 after the buffing of the rubber or without buffing, After washing, 1 minute and 10 minutes ultrasonic washing in a solution of 0.6WT% of oxalic acid, respectively, for 1 minute, washed with running water, dried, and then treated for 5 seconds to the plasma and then the adhesive was performed with an aqueous adhesive.

As shown in FIG. 3, under the buffing condition, cutting failure of all rubber materials occurred with an adhesive strength of 20 kgf / 2 cm or more.
In other words, the effect of buffing is clearly shown.
In order to simplify the process and develop various processes, the development of the adhesion process was performed without the buffing process.
In general, the required shoe adhesion varies slightly between manufacturers, but requires more than about 2.5 to 3.5kgf / cm.
The result of Experiment 1 has exceeded the reference value. At low temperatures of 37 ° C., the washing time of the fisheries was found to directly affect adhesion, which means that a longer washing time is required at lower temperatures.
In other words, it can be seen that the temperature of the solution is very important in the case of the hydroxyl washing.

Figure 4 in the Experimental Example 2 of the first embodiment according to the present invention after washing for 1 minute with ozone water, after washing for 1 minute with various temperature of the fish, after drying, after modifying the plasma surface, performing adhesion with an aqueous adhesive, after 24 hours As a diagram showing the adhesive properties of rubber, the adhesive strength increases as the temperature is increased, and shows partial fracture at 60 ° C or higher.

Figure 5 in the Experimental Example 3 of the first embodiment according to the present invention after washing for 1 minute with ozone water, washed for 3 minutes with various temperature of the fish, after drying, after modifying the plasma surface, performing an adhesion with an aqueous adhesive, after 24 hours As a diagram showing the adhesive properties of the rubber, the temperature 50 ℃ and 60 ℃ shows the cut fracture of the complete failure, 70 ℃ and 75 ℃ shows the partial failure rather than the adhesive strength.
High temperatures and long cleaning times damage the surface of the rubber material, resulting in reduced adhesion.
The most suitable fish-cleaning condition is shown as 2 minutes at a temperature of 50-60 ° C. However, in actual production, a high temperature of 70-75 ° C is required for 1-minute washing, since a small washing time is related to productivity.
In practice, the adhesive strength level is all met above 50 ° C.

Figure 6 in the Experimental Example 4 of the first embodiment according to the present invention after washing for 1 minute with ozone water, 2 minutes washing with various concentrations of 60 ° C., and after drying, after modifying the plasma surface, and performing the adhesion with an aqueous adhesive, After 24 hours, the diagram showing the adhesive properties of the rubber, the rubber concentration was changed from 0.05% to 0.6%, the rubber was washed, and the plasma was treated with an aqueous adhesive.
The adhesive strength at the concentration of 0.05% is also reaching the standard value, but the optimum concentration is more than 0.3%, causing partial breakdown and showing almost similar adhesive strength.

Figure 7 in the Experimental Example 5 of the first embodiment according to the present invention, after washing for 1 minute with ozone water, washed with a 60W aquatic acid solution of 0.5WT% for various times, after drying, after modifying the plasma surface, performing adhesion with an aqueous adhesive In addition, after 24 hours, the adhesion property of IP (EVA) was shown, and all of the adherend IPs were destroyed regardless of the fish-washing time.
The experiment showed the effect of the fish-washing, showing that the adhesive strength of 8kgf / 2cm or more of the adherend is destroyed after the fish-washing, compared to about 2kgf / 2cm when there is no fish-washing.
In the measurement of tensile adhesive strength, there is a sharp drop by knife.

FIG. 8 is a diagram showing adhesion characteristics of PU after gently washing with a surfactant in Experimental Example 6 of Example 1 according to the present invention, followed by drying, after plasma surface modification, and performing adhesion with an aqueous adhesive, and after 24 hours. PU is very sensitive to ozone water and easily discolored, so instead, it was gently washed with a surfactant, and then treated with an aqueous adhesive after 5 seconds treatment with plasma.
In the drawings, R means a rough surface and S means a smooth surface.

Table 1 shows the adhesion process and adhesive strength of each material in Experimental Example 7 of the first embodiment according to the present invention, after washing the surfactant, washing for 45 seconds in a 0.01 ~ 0.05WT% fish solution of 60 ℃, and after drying, At a speed of plasma treatment speed of 1 to 2 m / min, after treatment with a plasma of 1% oxygen in a nitrogen atmosphere, adhesion was carried out with an aqueous adhesive, and after 30 minutes, the adhesive strength was measured after 24 hours.
The use of primers of conventional chemicals shown in Table 2 shows better or similar adhesion strengths.

Table 1. Adhesion Process and Adhesion Strength by Material (Hydrogen Treatment; 45 sec)

Adherend wash
(Surfactants)
Pretreatment Gas type and content Plasma processing speed (cm / min)
Number of plasma treatments Adhesive strength (kgf / 2cm) N ₂ O ₂ 30min 24hr
Rubbbe
O Fisheries
0.05wt%
45 sec
50
0.5
200
One

5.9 *

6.4 *
CMP
X Fisheries
0.05wt%
45 sec
50
0.5
200
One
Rubber
O Fisheries
0.01wt%
45 sec
50
0.5
100
One

4.0

7.4 *
IP
O Fisheries
0.01wt%
45 sec
50
0.5
200
One
Rubber
O Fisheries
0.01wt%
45 sec
50
0.5
200
One

3.8

7.7
PU
X Bio T
MaX
4 brushing
50
0.5
200
One

Rubber ; EVA  And PU Fishery and treatment time of the same concentration,

         Plasma speed 200cm / min

         *; Destroy more than 50% of deposits

Table 2. Adhesive Strength of Existing Practical Processes Using Primers

Adherend Interface
Active agent Bio T MAX Fisheries
process
(0.01%)
primer UV
Cured primer
glue Peel strength (kgf / 2cm) 30min 24hr Rubber O - 45 sec 007 - W-01 5.1 * 5.8 * CMP - - - - P-5-2 Rubber O - 45 sec 007 - W-01 5.4 * 7.7 * IP O - - - P-5-2 Rubber O - 45 sec 007 - W-01 2.3 5.6 PU - O - W-104 -

9 is a view showing adhesion characteristics of rubber after washing with plasma active water for various times in Experimental Example 7 of the second embodiment according to the present invention, after drying, after modifying the plasma surface, and performing an adhesion with an aqueous adhesive, and after 24 hours. In the plasma activated water, the concentration of ozone was 0.6 ppm and the concentration of hydroxyl was 0.6 wt%.
All have shown excellent adhesive strength by which an adherend is destroyed.

In the present invention, when comparing the experimental results of the second embodiment of the plasma active water combined with ozone water and hydroxyl and the numerous experimental results of the separated first embodiment, there is no significant difference in the adhesive properties.
The second embodiment in which the two processes are combined has an advantage of shortening the process as compared with the first embodiment.

 While the invention has been shown and described in connection with specific embodiments thereof, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention as indicated by the appended claims. Anyone with knowledge will know it easily.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows a first embodiment of a shoe bonding method by an atmospheric plasma according to the present invention.

Figure 2 schematically shows a second embodiment of the shoe bonding method by the atmospheric plasma according to the present invention.

Figure 3 is a view showing the adhesion characteristics according to the presence or absence of the buffing rubber and the washing time of the fish in Experimental Example 1 of the first embodiment according to the present invention.

4 is a view showing the adhesive properties of the rubber after washing the fish 1 minute of various temperatures in Experimental Example 2 of the first embodiment according to the present invention.

Figure 5 is a view showing the adhesive properties of the rubber after washing the fish 3 minutes of various temperatures in Experimental Example 3 of the first embodiment according to the present invention.

6 is a view showing the adhesive properties of the rubber according to the concentration of the aqueous solution in Experimental Example 4 of the first embodiment according to the present invention.

7 is a view showing the adhesion characteristics of IP (EVA) according to the fish-washing time in Experimental Example 5 of the first embodiment according to the present invention.

8 is a view showing the adhesive properties of the PU after the plasma surface modification in Experimental Example 6 of the first embodiment according to the present invention.

9 is a view showing the adhesive properties of the rubber according to the PAW cleaning time in Experimental Example 7 of the second embodiment according to the present invention.

Claims (4)

After the shoe material was put in, it was washed for 10 seconds to 10 minutes with ozone water having a concentration of 0.01 to 30 ppm or a surfactant having a concentration of 0.0001 to 10 wt% at a temperature of 0 to 80 ° C., and a temperature of 0 to 80 ° C. After washing for 10 seconds to 10 minutes in an aqueous solution having a concentration of 0.0001 to 10 wt% in, dried, plasma surface modified, coated with an aqueous adhesive or a solvent-type adhesive, and then dried, pressed Shoe adhesion method by atmospheric pressure plasma, characterized in that the progress was made. After putting the shoes material, the fish solution having a concentration of 0.0001 to 10wt% in the temperature 0 ~ 80 ℃ range is washed with plasma active water having a ozone concentration of 0.01 ~ 30ppm by plasma treatment for 10 seconds to 10 minutes And drying, drying, plasma surface-modifying, applying an aqueous adhesive or a solvent-type adhesive, and then drying and pressing are sequentially performed. The method of claim 1, The method of adhering shoes by atmospheric plasma, wherein the plasma surface is modified by applying atmospheric pressure plasma or vacuum plasma. The method of claim 1, The method of adhering shoes by atmospheric pressure plasma, characterized in that made of at least one of air, nitrogen, oxygen, argon, CF ₄ , SF ₆ , C ₂ H ₂ , CH ₄ gas as the working gas of the plasma surface modification.

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