JP2006007059A - Barrier film forming method and barrier film forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrier film forming method and a barrier film forming apparatus capable of forming a tough, even and uniform barrier film at a low cost by means of spraying against a material to be coated. <P>SOLUTION: A spray part 12 is provided with two sprayers 25, 26, for example. The sprayers 25, 26 have respectively supply tanks 25a, 26a and spray guns 25b, 26b which are extended from the supply tanks 25a, 26a. A barrier agent 25c for forming a barrier film and a binder agent 26c for fixing the barrier film to the material 2 to be coated are respectively stored in the supply tank 25a and the supply tank 26a and are sprayed respectively toward the material 2 to be coated from the spray guns 25b, 26b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a barrier film forming method and a barrier film forming apparatus for forming a barrier film on the surface of an object to be coated such as a resin.

  For example, a resin container containing a detergent, a beverage, or the like is used to prevent the permeation of gas (gas) inside and outside the container through the resin layer and to protect the contents from alteration such as oxidation. In many cases, a barrier film (gas barrier material) is formed on the outer surface. Conventionally, a method of forming such a barrier film of a resin container on a resin container by a method such as laminating or printing is known. Also, a method of forming a water-soluble barrier film on the outer surface of a resin container is known in order to efficiently obtain a more uniform barrier film than such lamination and printing.

  However, the conventional barrier film forming methods such as laminating and printing as described above have a problem that the resin container is deformed by being exposed to a high temperature and the manufacturing cost is increased.

  The present invention has been made in view of the above circumstances, and provides a barrier film forming method and a barrier film forming apparatus capable of forming a uniform, uniform barrier film at low cost by spraying on an object to be coated. The purpose is to provide.

  In order to achieve the above object, according to the present invention, there is provided a barrier for forming a barrier film on the surface of an object to be coated, having at least two spray guns directed to a region of the object to be coated. The liquid to be coated from two or more spray guns in any combination of a liquid having a property, a liquid having a binder property for fixing the barrier film to the coating object, or a liquid having a barrier property and a binder property And forming the barrier film by spraying toward one region of the object and applying the liquid to the object to be coated while mixing the liquid on the surface of the object to be coated. A method is provided.

  You may further provide the process of exposing the said to-be-coated article to negative ion environment. It is also preferable to further include a step of performing a plasma treatment on the object to be coated. A step of subdividing the barrier agent and / or the binder agent cluster may be further provided before or during the injection. The step of subdividing the barrier agent and / or the binder agent may be performed by microwave irradiation or magnetic field application. A step of forming the barrier film on the object to be coated and then drying by irradiating microwaves may be further provided.

  In addition, according to the present invention, there is provided a resin container characterized in that a barrier film is formed on the surface by the barrier film forming method described above.

  Further, according to the present invention, the liquid having barrier properties for forming a barrier film on the surface of the object to be coated, having at least two spray guns directed to one region of the object to be coated, A liquid having a binder property for fixing a barrier film to the object to be coated, or a liquid having a barrier property and a binder property in any combination from two or more spray guns to one region of the object to be coated. A barrier film forming apparatus comprising: a spraying unit that sprays the liquid and mixes the liquid on the surface of the coating object and applies the liquid to the coating object to form the barrier film on the coating object Is provided. You may further provide the plasma processing part which exposes the said to-be-coated object to a negative ion environment, and performs a plasma processing.

  According to the present invention, a barrier agent or a binder agent can be separately sprayed from a plurality of spray guns and mixed immediately before adhering to the surface of the object to be coated, so that it can be employed in the formation of a barrier film by conventional spraying. Combinations of barrier agents and binders that were not available can be used. As a result, a barrier film having better gas barrier properties and durability than conventional barrier films can be formed by spray coating.

  In addition, when plasma treatment is performed on the surface of an object to be coated, the wettability of the surface of the object to be coated is greatly increased by placing the object to be coated in an environment with a lot of negative ions as compared with conventional plasma treatment. It becomes possible to raise.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a barrier film forming apparatus used in the barrier film forming method of the present invention. The barrier film forming apparatus 1 includes a plasma processing unit 11, an injection unit 12, and a drying unit 13. The plasma processing unit 11 includes, for example, a corona discharge device 21 and a negative ion generator 22. The corona discharge device 21 generates a plasma state by discharge and performs a plasma treatment on the surface of the object to be coated (resin container) 2. Examples of the article to be coated (resin container) 2 include a resin container such as a container for detergent.

  The negative ion generator 22 makes the air in the plasma processing unit 11 into a negative ion atmosphere. When the corona discharge device 21 performs plasma processing on the surface of the target object 2, the target object 2 is subjected to a negative ion environment. Play a role below.

  When performing the plasma treatment on the surface of the object to be coated 2, the surface of the object to be coated 2 is greatly wetted compared to the conventional plasma treatment by placing the object to be coated 2 in an environment with a lot of negative ions. Can be increased. In addition, the negative ion generator 22 which exposes such a to-be-coated object 2 to a negative ion environment is pre-processed as a pre-treatment before performing the surface plasma treatment of the to-be-coated object 2 with a plasma processing apparatus such as the corona discharge device 21. A configuration in which plasma treatment is performed after exposing 2 to a negative ion environment may be employed.

  The injection unit 12 includes, for example, two spray devices 25 and 26. The spray devices 25 and 26 have supply tanks 25a and 26a, and spray guns 25b and 26b extending from the supply tanks 25a and 26a, respectively. As an example of the combination, in the supply tank 25a, a liquid having a barrier property (hereinafter referred to as a barrier agent) 25c for forming a barrier film is fixed, and in the supply tank 26a, the barrier film is fixed to the article 2 to be coated. Liquids having binder properties (hereinafter referred to as binder agents) 26c are respectively accommodated and sprayed from the spray guns 25b and 26b toward the object 2 to be coated.

  A magnetic field generator 27 is provided in the middle of the flow path between the spray guns 25b and 26b and the supply tanks 25a and 26a. The magnetic field generator 27 may be composed of, for example, a permanent magnet. Such a magnetic field generator 27 applies a magnetic field to the barrier agent 25c supplied from the supply tank 25a to the spray gun 25b and to the binder agent 26c supplied from the supply tank 26a to the spray gun 26b, so that the barrier agent 25c and the binder are applied. Clusters that are molecular aggregates of the agent 26c are subdivided. Thus, by dividing | segmenting a cluster, the barrier agent 25c and the binder agent 26c are activated, and are smoothly apply | coated to the to-be-coated article 2. FIG.

  As shown in FIG. 2, the spray guns 25 b and 26 b are arranged so as to face each other at a predetermined angle and cross toward one point on the surface of the workpiece 2. As a result, the barrier agent 25c sprayed from the spray gun 25b and the binder agent 26c sprayed from the spray gun 26b collide just before adhering to the surface of the article 2 to be mixed and become a fine mist. Then, it is applied to the surface of the article 2 to be coated.

  Thus, by spraying the barrier agent 25c and the binder agent 26c separately from the two spray guns 25b and 26b, respectively, and mixing them immediately before adhering to the surface of the object 2 to be coated, It becomes possible to freely select the barrier agent 25c and the binder agent 26c whose combination is limited.

  That is, in the past, since a mixed solution in which a barrier agent and a binder agent were mixed in advance was applied to an object to be coated with a single spray gun, when the barrier agent and the binder agent were mixed, they solidified or reacted. A combination of a barrier agent and a binder agent that cannot be combined with each other and cannot be solidified when mixed and do not react with each other has been extremely limited.

  However, as in the present invention, the barrier agent 25c and the binder agent 26c are sprayed separately from the two spray guns 25b and 26b, respectively, and mixed immediately before adhering to the surface of the article 2 to be coated. It becomes possible to employ a combination of a barrier agent and a binder that could not be employed in the formation of a barrier film by spraying. As a result, a barrier film having better gas barrier properties and durability than conventional barrier films can be formed by spray coating.

  In addition to the example in which two spray guns are provided as in this embodiment, three or more spray guns may be formed. In addition, each supply tank has a combination of a liquid having both barrier properties and binder properties and a liquid having binder properties, and a combination of a liquid containing a surface coating agent that protects the barrier film. Any combination of various solutions for forming the barrier film may be employed, and the present invention is not limited to the combinations exemplified in this embodiment.

  The spray unit 12 is preferably provided with a work rolling device 28 that rotates the workpiece 2 and passes the front surfaces of the spray guns 25b and 26b. By such a workpiece rolling device 28, the object to be coated 2 passes in front of the spray guns 25b and 26b while rotating, and the mixture of the barrier agent 25c and the binder agent 26c is uniformly applied to the entire surface of the object to be coated 2. The

  The barrier agent 25c and the binder agent 26c are preferably preliminarily irradiated with microwaves by the microwave device 29 before being accommodated in the supply tanks 25a and 26a. By irradiating the barrier agent 25c and the binder agent 26c with microwaves in advance using the microwave device 29, the clusters that are molecular aggregates of the barrier agent 25c and the binder agent 26c can be further subdivided. The barrier agent 25c and the binder agent 26c can be more activated in combination with the above-described clustering by the magnetic field generator 27, and can be smoothly applied to the article 2 to be coated.

  As shown in FIG. 3, the drying unit 13 includes a blower device 31 and a microwave device 32. The blower 31 applies a wind of 100 ° C. or less, such as a room temperature wind, toward the article 2 having a barrier film coated on the surface. Moreover, the microwave apparatus 32 irradiates microwave toward the to-be-coated object 2 which passed the air blower 31, and evaporates the water | moisture content of the inner surface of the barrier film formed by coating efficiently.

  Thus, by forming the drying unit 13 with the combination of the blower 31 and the microwave device 32, compared to the case where the object 2 is dried with high-temperature hot air as in the past, the object 2 is not coated. Without excessively increasing the temperature, the moisture in the barrier film is efficiently dried in a short time. Resin containers as an example of such an object to be coated 2 are mostly thermoplastic resins, and depending on the combination of the material and thickness of the container, thermal management when drying the barrier film is very important. In order to prevent deformation, it was necessary to experimentally establish drying conditions (including equipment) for each resin container. However, as in the present invention, by using the microwave device, the moisture inside the barrier film is also efficiently evaporated, and the coated film 2 is dried without deforming in a short time, and the barrier film is strong on the surface. Can be formed continuously.

  Next, the barrier film forming method of the present invention using the barrier film forming apparatus configured as described above will be described. The barrier film forming method of the present invention can be suitably used for forming a barrier film for imparting gas barrier properties to, for example, a thermoplastic resin container by spray coating.

(1) Step of improving wettability An object to be coated 2 on which a barrier film is formed by the barrier film forming method of the present invention is exposed to a negative ion atmosphere by a negative ion generator 22 and then coated by a corona discharge device 21. 2 is subjected to plasma treatment. The wettability of the surface of the coating object 2 that has been subjected to the plasma treatment after placing the coating object 2 in an environment with a lot of negative ions is greatly improved.

(2) Coating process The coated object 2 whose surface wettability is greatly enhanced in the previous process passes through the spray guns 25b and 26b while rotating depending on the workpiece rolling device 28. Here, a liquid (barrier agent) 25c having a barrier property and a liquid (binder agent) 26c having a binder property ejected as fine mist from spray guns 25b and 26b facing each other at a predetermined angle, respectively, They collide just before adhering to the surface of the object 2 to be coated, and are further mixed into a very fine mist and applied to the surface of the object 2 to be coated.

  The barrier agent 25c and the binder agent 26c are preliminarily irradiated with microwaves by the microwave device 29 to subdivide the clusters, and further, the clusters are further subdivided by the magnetic field generator 27 immediately before the injection, thereby being activated. The barrier agent 25c and the binder agent 26c are mixed on the surface of the article 2 to be coated, and the barrier film is smoothly applied to the article 2 to be coated.

(3) Drying process As shown in FIG. 3, the object to be coated 2 having a barrier film formed on the surface is exposed to a wind of 100 ° C. or lower, such as a room temperature wind, by a blower 31 to dry the surface portion. Thereafter, the microwave is irradiated by the microwave device 32 to efficiently evaporate the moisture on the inner surface of the barrier film. Thereby, the water | moisture content of a barrier film | membrane is efficiently dried in a short time, without raising the temperature of the to-be-coated article 2 extremely. A strong barrier film having excellent gas barrier properties is formed on the surface of the object to be coated 2.

FIG. 1 is an explanatory view showing a barrier film forming apparatus of the present invention. FIG. 2 is a cross-sectional view showing a spray gun. FIG. 3 is a cross-sectional view showing the drying unit.

Explanation of symbols

1 Barrier film forming device 2 Object to be coated (resin container)
DESCRIPTION OF SYMBOLS 11 Plasma processing part 12 Injection part 13 Drying part 22 Negative ion generator 25b, 26b Spray gun 25c Barrier agent (liquid with barrier property)
26c Binder agent (Liquid having binder properties)
27 Magnetic field generator 29, 32 Microwave device

Claims (9)

  A liquid having a barrier property for forming a barrier film on the surface of the object to be coated, the liquid film having at least two spray guns directed to a region of the object to be coated, and the barrier film on the object to be coated A liquid having a binder property for fixing, or a liquid having a barrier property and a binder property is sprayed from one or more spray guns to one region of the object to be coated, and the object to be coated And a step of forming the barrier film by mixing the liquid on the surface and applying the liquid onto the object to be coated.   2. The barrier film forming method according to claim 1, further comprising a step of exposing the object to be coated in a negative ion environment.   The barrier film forming method according to claim 1, further comprising a step of performing a plasma treatment on the object to be coated.   2. The method according to claim 1, further comprising a step of subdividing the liquid having the barrier property, the liquid having the binder property, or the liquid cluster having the barrier property and the binder property before or during the injection. Item 4. The barrier film forming method according to any one of Items 1 to 3.   The step of subdividing the liquid having the barrier property, the liquid having the binder property, or the cluster of the liquid having the barrier property and the binder property is irradiation with a microwave or application of a magnetic field. The method for forming a barrier film according to claim 4.   The method for forming a barrier film according to claim 1, further comprising a step of drying by irradiating microwaves after forming the barrier film on the object to be coated.   A resin container having a barrier film formed on the surface thereof by the barrier film forming method according to claim 1.   A liquid having a barrier property for forming a barrier film on the surface of the object to be coated, the liquid film having at least two spray guns directed to a region of the object to be coated, and the barrier film on the object to be coated A liquid having a binder property for fixing, or a liquid having a barrier property and a binder property is sprayed from one or more spray guns to one region of the object to be coated, and the object to be coated An apparatus for forming a barrier film, comprising: an ejecting unit that forms the barrier film on the coating object by applying the liquid to the coating object while mixing the liquid on the surface thereof. The barrier film forming apparatus according to claim 8, further comprising a plasma processing unit that performs plasma processing by exposing the object to be coated to a negative ion environment.

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