KR970001214B1 - Covering method of a high molecular substance - Google Patents

Abstract

Process for coating an organic polymer resin powder on a glassware is described. For an example, a glassware with a volume of 150ml is spray ed with silanol as a coupling agent, sprayed with polyester powder, having a specific gravity of about 1.5 and a particle size of 20 microns, charged with static electricity by a corona charge of 30,000-50,000V, heated at 180 deg.C for 10 min, and cooled slowly to room temperature. The covering depth is 120 microns, covering weight is 3.0 g, covering efficiency is 98.3 %.

Description

Coating method of organic polymer powder on the surface of glass container

The present invention relates to a method for coating the outer surface of a glass container, and more particularly, to a method for coating the outer surface of a glass article by spraying organic polymer synthetic resin powder.

Conventionally, a method of coating the surface of a glass container using an inorganic material or an organic material is already well known to those skilled in the art. The purpose of coating the glass container using inorganic or organic materials is that the outer shock and internal pressure are strong, and the film acts as a kind of protective film when it is ruptured. To prepare.

As a technique known to date, there is a method of coating a glass container using an inorganic material, and the coating method using the inorganic material is based on a liquid spray method. Since the liquid spraying method first uses an inorganic material, the glass container, which is to be coated, needs to be heat-treated at a high temperature of 500 to 600 ° C., and therefore, the high temperature heat treatment cost has a considerable disadvantage. In addition, in order to lower the melting point of the coated inorganic material, the heavy metal such as lead is contained in the inorganic material powder, causing serious pollution problems with the dust generated during liquid injection. This liquid spray method has a low arrival rate (20-30%) to the coated object, causing a large amount of raw material loss, which is a factor in the cost increase, and has a problem in color robustness, stability and beauty.

In order to solve the drawback of the coating method of the inorganic material by the liquid injection method, the coating method using the organic material was developed. This method is a liquid spray using an organic material instead of an inorganic material, a liquid epoxy or acrylic resin was used as the organic material, benzene and the like as the solvent. Unlike the method using the inorganic material, the method of using the organic material could be coated by maintaining the temperature at about 150 ~ 180 ℃. However, this method also has the same problems as liquid phase spraying of inorganic materials, except that the heat treatment temperature is changed from a high temperature of 500 to 600 ° C. to a low temperature of 150 to 180 ° C. to reduce energy consumption.

In particular, the reduction of consumption of raw materials, which make up a large portion of the production cost, is impossible to recover from liquid coatings of organic or inorganic materials, and the film thickness can only arrive within 15 µm. The strength of is also not obtained. In addition, benzene, which is used as a solvent, is highly volatile and has a low flash point, making it difficult to rule out the risk of fire. There will be a problem.

In order to solve this problem, after spraying a coupling agent (coupling agent) to the glass container to be coated, preheated for 10 to 20 minutes at a temperature of 180 ~ 220 ℃, about 30,000 ~ 50,000 V corona discharge in the preheated glass container And then spraying the organic polymer resin powder with charged particles with an injector, followed by curing heat treatment for 10 to 20 minutes at a temperature of 180 ~ 200 ℃, the powder is fused to the glass container surface, and then heated glass to a heating furnace A method of cooling out at room temperature was developed. However, this method requires a separate preheating treatment in order to efficiently spray the organic polymer resin powder onto the surface of the glass container, and thus has a problem of increasing the production cost in view of reducing energy consumption.

The present inventors have solved the above problems, as well as developing the organic polymer powder coating method for enhancing the resistance to the external impact and internal pressure to cover the surface of the glass container, the formation of a protective film at the time of rupture and the production of a beautiful container.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating method for the surface of a glass container that produces a glass container that is harmless to the human body by eliminating the use of a solvent harmful to the human body.

In addition, the present invention is to reduce the loss rate of the coating material to 5% or less to reduce the cost, to provide a coating method of the glass container surface that can enhance the impact resistance and pressure resistance of the glass container.

Therefore, in order to achieve the above object of the present invention, in the present invention, after injecting a binder to a coating material such as a glass container to be coated, the conductive material forms an electron hole by grounding and the polymer organic powder resin It is charged by the electrostatic charge and sprayed by an injector, and then heated for 7 to 15 minutes at a temperature of 180 ~ 200 ℃ to fusion powder on the surface of the object such as glass container. The heated glass container is removed from the heating furnace and cooled at room temperature.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

First, a binder dissolved in water is sprayed onto an object such as a glass container to be coated using an air sprayer or the like. The type of binder is selected according to the characteristics of the organic polymer resin to be used, and is usually selected from derivatives of silane. Thereafter, in order to increase the arrival efficiency of the organic polymer resin powder having a powder particle size of 10 to 80 µm, a subject such as a glass container forms electron holes, and the organic polymer resin powder has a constant voltage. In order to form an electron hole in the object, the arrival booth and the object support for arriving the organic polymer resin powder on the object are grounded, water is sprayed on the support, and then the object is attached to the support. Plugged in and sealed to allow water vapor to adsorb to the inner wall of the subject by spontaneous evaporation. When the organic polymer resin powder is accelerated to be evenly charged using compressed air, the particles collide with each other to generate friction, and static electricity is generated. do.

In this way, if the inside of the object is sprayed with water and grounded to form electron holes, and the injected organic polymer resin powder is made of + charged particles by friction, there is no need to preheat the subject to enhance adhesion in the conventional method. This has a great effect on energy savings.

In addition, by controlling the amount of charge charged to the organic polymer resin powder, the film thickness can be in the range of 80 to 150 µm, and the film thickness is changed by using the property of the organic polymer resin whose glossiness varies depending on the film thickness. You can also adjust the glossiness. The organic polymer resin powder to be used includes polyester, polyurethane, epoxy or epoxy-polyester resin powder.

When the spraying process is completed, the organic polymer powder particles are completely fused to the surface of the object by heating for 7 to 15 minutes at a temperature of 180 ~ 200 ℃. The heating temperature at this time is determined by the size of the workpiece and the curing conditions of the resin powder. In addition, the heating time after spraying is 7 to 15 minutes, which is proportional to the thickness and size of the glass container to be coated. For the relatively thin and small sized objects, heating for about 7 to 10 minutes is sufficient. A thick and large sized object can sufficiently melt the resin powder by heating it for about 11 to 15 minutes. After the heating process is completed, the coated object is gradually cooled to room temperature to finish coating the organic polymer powder on the coated object such as a glass container. In this process, the cooling time can be shortened by adopting a forced circulation air cooling method to prevent quenching and complete cooling.

In the case of coating the glass container by this method, the loss ratio of the organic polymer powder is 5% or less, and the thickness of the coating film is in the range of about 80 to 150 µm, which serves as a protective film for protecting the glass container or the like. .

Example 1

After injecting silanol as a binder into a glass container having a capacity of 150 m, a polyester powder (specific gravity of about 1.5, particle size of 20 µm) charged at a constant voltage of 70,000 V is sprayed, and then heated at a temperature of 180 ° C. for 10 minutes. It was fused to the container and cooled to room temperature.

Example 2

Under the same conditions as in Example 1, the concentration of water in the glass container was increased.

Example 3

Under the same conditions as in Example 2, the constant voltage of 70,000V was lowered to 42,000V.

Example 4

Under the same conditions as in Example 2, the size of the container was changed to 200 ml.

Example 5

Under the same conditions as in Example 2, the polymer organic resin powder was changed to epoxy (specific gravity 1.5, particle size 20 mu m).

Example 6

In the same conditions as in Example 2, the injection of the binder was omitted.

Example 7

Under the same conditions as in Example 2, formation of electron holes in the conductor was suppressed.

Experiment result

The following data were obtained for the film thickness, arrival weight, and arrival efficiency of the glass vessel produced in the above example.

Claims (1)

Spraying the conjugates selected from derivatives of silane and diluted in water using an air sprayer, preheating the above-mentioned subjects, and organically charged organic materials on the surface of the pre-heated subjects. Spraying the polymer resin powder; and heating and heating the substrate coated with the organic polymer resin powder at 180 ° C. to 250 ° C. for 7 to 15 minutes, and slowly cooling the heated object to room temperature. In a method of coating a surface of a glass container or the like, instead of preheating the above-described subject, the inside of the above-mentioned subject is placed in a water-resistant member support and sealed, so that the water adhered to the above-described object support. The method of coating the organic polymer powder on the surface of the glass container, characterized in that the water particles adhere to the inner wall of the subject by evaporation.