KR20070050852A - Process for curing ultraviolet-curable resins, process for producing flat panels, and apparatus for ultraviolet irradiation - Google Patents

Abstract

The present invention provides a method for curing a highly reliable ultraviolet curable resin, a method for producing a flat panel using the same, and a low-cost, low-power consumption, long-life, and compact ultraviolet irradiation device useful for carrying out these methods.

Moreover, this invention provides the hardening method which maintains the oxygen concentration on a resin surface at 5 volume% or less when irradiating an ultraviolet-ray from a light emitting diode to an ultraviolet curable resin. The apparatus includes a support for supporting a target object, a means for irradiating ultraviolet rays from the light emitting diode, and a means for controlling the oxygen concentration on the surface of the target object by supplying an inert gas around the target object. .

UV curable resin, flat panel, UV irradiation device

Description

Process for Curing Ultraviolet-curable Resins, Process for Producing Flat Panels, and Apparatus for Ultraviolet Irradiation

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically embodiment of the ultraviolet irradiation device which concerns on this invention.

2 is a diagram showing a relationship between oxygen concentration and surface curability.

<Brief description of symbols for the main parts of the drawings>

1 UV irradiation device

2 support

3 boards

4 UV curable resin film

5 holding

6 rails

7 UV irradiator with light emitting diode

8 hood

9 inert gas supply line

The present invention relates to a method for curing an ultraviolet curable resin without inhibiting oxygen using an ultraviolet light emitting diode, a method for producing a flat panel using the curing method, and an ultraviolet irradiation device useful for carrying out these methods.

Conventionally, when hardening ultraviolet curable resin for electrode protective materials of flat panels, such as a liquid crystal panel, a PDP, organic EL, an electrodeless high pressure mercury lamp, an electrode high pressure mercury lamp, an electrodeless halogenated metal lamp, an electrodeless halogenated metal lamp, a xenon lamp, an ultrahigh pressure The light of at least one lamp selected from a mercury lamp and a mercury xenon lamp was irradiated to cure the resin. However, these light sources are very expensive, have a short lifespan, generate a large amount of heat, and thus have a large power consumption. In addition, in recent years, due to the increase in size of flat panels, the coating area has been widened, and in order to cure the resin coated on the large area, it is necessary to arrange the lamps in a wide range so as to be applied to a large area, and a large-scale apparatus is required.

Moreover, although the ultraviolet curable resin of the various forms is proposed, the radical component resin which introduce | transduced the radical reactive functional group in most cases is a main component. It is believed that these radically polymerized resins react with radicals generated by ultraviolet irradiation, whereby curing proceeds. Since hardening advances to a radical reaction, hardening is complete | finished in a very short time, and high productivity can be expected. However, when the radically polymerized ultraviolet curable resin is cured by ultraviolet irradiation, there is a problem that it often causes a curing failure because radical reaction is easily inhibited by oxygen molecules in the air.

Therefore, the present invention eliminates the above-mentioned drawbacks of the prior art, and is a method of curing a highly reliable ultraviolet curable resin, a method of manufacturing a flat panel using the same, and a method capable of carrying out these methods, inexpensive, low power consumption, and high lifespan. And aims to provide a compact ultraviolet irradiation device.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, as a light source which provides the ultraviolet-ray of the wavelength required for hardening | curing with respect to an ultraviolet-curable resin, the light-emitting diode which emits an ultraviolet-ray, The present invention was completed by discovering that the above object can be achieved by irradiating and curing ultraviolet rays having a oxygen concentration of 5% or less on the surface.

Specifically,

Firstly, the present invention

In the method of irradiating ultraviolet curable resin with ultraviolet rays to cure the resin, a light emitting diode is used as the light source of the ultraviolet ray, and at the time of ultraviolet irradiation, the oxygen concentration on the surface of the ultraviolet curable resin is 5% or less (% as described later). It means "vol%" and is the same below), It provides the hardening method of the ultraviolet curable resin characterized by the above-mentioned. At this time, 5% or less of oxygen concentration includes the case where oxygen is not included. That is, it means 5 volume% or less and 0 volume% or more. The oxygen concentration is preferably 3% or less and 0% or more, and more preferably 1% or less and 0% or more.

The term "ultraviolet curable resin" described in the present specification is not particularly limited, and the present invention is effective as long as it is an ultraviolet curable resin. As a typical example of ultraviolet curable resin, an ultraviolet curable silicone resin composition is mentioned.

As the "light emitting diode" described in the present specification, an ultraviolet light emitting diode is particularly preferable.

As used herein, the term "oxygen concentration at the surface" of an object such as an ultraviolet curable resin means a volume concentration (vol%) of oxygen in the gas phase in a space within 1 cm of the surface. Unless otherwise specified, the unit "%" means volume% with respect to oxygen concentration.

In this specification, a "substrate" means the board | substrate used for flat panels, such as a liquid crystal panel, a PDP, organic EL, for example, and an "electronic component" means an electrode etc., for example.

In a preferred embodiment of the curing method of the present invention, the oxygen concentration on the surface of the resin is maintained at 5% or less by introducing an inert gas around the surface of the ultraviolet curable resin.

In this specification, "inert gas" is nitrogen gas, argon gas, etc., for example.

In the present invention, the method of controlling the oxygen concentration on the resin surface to 5% or less is not particularly limited.

The said ultraviolet curable resin hardened | cured by the said method may be formed in the film form on the board | substrate in order to seal the electronic component provided in the board | substrate.

The film-like UV curable resin has a wide area and sometimes a large area. However, in one embodiment, the UV light emitted from the light emitting diode is moved so as to be scanned onto the film in accordance with the shape of the resin film.

In order to make the ultraviolet light emitted from the light emitting diode be scanned on the resin film, scanning is performed in a straight line in one direction, in a reciprocating direction in a straight line, or in a two-dimensional direction in which a specific direction and a direction perpendicular thereto are combined. There is a way. This can be suitably selected according to individual circumstances such as the shape and area of the resin film, the curability of the resin, and the like.

Secondly, the present invention

The electronic component provided on the board | substrate was coat | covered with the film | membrane of ultraviolet curable resin, and this resin film is irradiated with the ultraviolet-ray from a light emitting diode, and this resin film is hardened | cured in the state which kept the oxygen concentration in the resin surface below 5%. It provides a method for producing a flat panel comprising the.

In the method of manufacturing the flat panel, the ultraviolet curable resin film has a wide area and sometimes a large area. However, in one embodiment, the ultraviolet light emitted from the light emitting diode is moved so that the ultraviolet light is scanned onto the film according to the shape of the resin film. Is done. As a result, in this invention, a large area can also be responded with a small irradiation apparatus.

In the present specification, examples of the "flat panel" include the above-mentioned liquid crystal panel, PDP, organic EL, and the like.

Thirdly, the present invention is a device suitable for carrying out the above-mentioned curing method and flat panel manufacturing method.

Support for supporting the object,

Means for irradiating ultraviolet light to the target object having a light source comprising a light emitting diode, and

Means for controlling the oxygen concentration on the surface of the object by supplying an inert gas around the object

Provided is an ultraviolet irradiation device for a target object, characterized in that provided.

When the treatment body provided in the apparatus is coated on a substrate and has a large, sometimes large, workpiece, the ultraviolet rays irradiated to the treatment object are moved so that ultraviolet rays can be scanned onto the coating object. It is preferable to further provide the irradiation light moving means to make.

Moreover, in another embodiment, the said ultraviolet irradiation means is equipped with the several light emitting diode arrange | positioned in one row or two rows or more in one plane or curved state. According to this embodiment, compared with the case of a light emitting diode having one light source, it is excellent in that ultraviolet rays can be irradiated over a large area at one time.

It is preferable that the said ultraviolet irradiation device is further provided with the means which adjusts the distance of the said light emitting diode and a to-be-processed object. When the to-be-processed object is an ultraviolet curable resin, it is possible to adjust so that suitable curability may be obtained.

The oxygen concentration control means used in the ultraviolet irradiation device includes, for example, a hood which covers the ultraviolet irradiation means in a bell shape, the top of which is clogged and the lower part is opened, and which is connected to the hood to supply an inert gas into the hood. The thing which has an inert gas supply line is mentioned.

The said oxygen concentration control means mentioned above may be made to move according to the structure which the said ultraviolet irradiation device moves by the said irradiation light moving means. In addition, the oxygen concentration control means and the ultraviolet irradiation means may be integrated.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described based on drawing.

1 is a diagram schematically showing an example of an ultraviolet irradiation device 1 according to the present invention. The ultraviolet curable resin is apply | coated on the board | substrate 3 mounted on the support stand 2, and the film 4 of the said resin is formed. The support 5 is fixed vertically near one end of the support 2, and the rail 6, which is horizontal at a constant height, is fixed freely in the support 5 above. The rail 6 is supported by an ultraviolet irradiator 7 equipped with a light emitting diode as a light source at the lower end thereof so as to be able to move on the rail 6, and at an arbitrary speed on the rail 6 by a driving device (not shown). To move in the desired direction. The hood 8 which covers the ultraviolet irradiator 7 in the shape of a bell is provided, and the hood 8 is open at the lower end, and the upper ceiling is substantially blocked except that the inert gas supply pipe 9 is connected from the outside. The contact portion or proximity to the rail 6 is also substantially airtight or the leakage is minimized. This hood 8 is comprised so that the ultraviolet irradiator 7 may move together when it moves the rail 6.

The oxygen concentration on the surface of the resin film 4 is, for example, taken out of a gas within a space of 1 cm from the surface of the film, and measured by an oxygen concentration meter. And the flow volume of inert gas introduction from the inert gas supply line 9 is adjusted so that the said density may become a desired value. This can be done manually or automated. Automation is, for example, the flow rate of the inert gas from the supply pipe 9 on the basis of data obtained by extracting a gas in a space within 1 cm from the surface of the film 4, for example, within 1 cm of the film surface and introducing the gas into the oxygen concentration meter. To adjust.

The coating film 4 coated with the ultraviolet curable resin has a large area so that the entirety cannot be irradiated with the light of the light emitting diode when the ultraviolet irradiator 7 is stopped at a certain position. However, since the ultraviolet irradiator 7 is moved to scan the film 4 in accordance with the shape of the film 4 by the irradiation light moving device made of the rail 6, a driving device (not shown), or the like, the entire range of the film 4 is covered. Irradiate and harden. By setting the moving speed of this ultraviolet irradiator 7, it is possible to set hardening time freely.

In addition, although the amount of light of one light emitting diode is relatively small, a larger range can be irradiated by one irradiation than in one case by using an ultraviolet irradiator in which a plurality of light emitting diodes are arranged in one row or two rows or more. The cured resin can obtain a large amount of light. The method of arranging a plurality of light emitting diodes may be a direction perpendicular to, or parallel to, the direction of movement of the ultraviolet irradiator 7. In addition, even if the moving speed of the ultraviolet irradiator 7 is increased, the amount of ultraviolet light received from the ultraviolet irradiator can be sufficient. The amount of received light can also be increased by reciprocating the ultraviolet irradiator 7.

In addition, in the illustrated embodiment, since the rail 6 can adjust the position freely along the support 5 in the up and down direction, the ultraviolet irradiator 7 is brought close to the cured resin film 4 to be irradiated. It is also possible for the coating 4 to efficiently receive the ultraviolet rays from the ultraviolet irradiator 7. By doing in this way, even if it speeds up the movement of the ultraviolet irradiator 7, it becomes possible to receive enough ultraviolet-ray from a light emitting diode, and it becomes possible to shorten hardening time.

As described in the prior art, when the radical polymerization type ultraviolet curable resin is cured by ultraviolet irradiation, radical reaction may be inhibited by oxygen molecules in the air. In particular, since the ultraviolet wavelength generated from the light emitting diode becomes a single peak wavelength of 300 nm to 400 nm due to its characteristics, a conventional electrodeless high pressure mercury lamp having a wide light emission wavelength band, an electrode high pressure mercury lamp, an electrodeless halogenated metal lamp, and an electrode Light energy is lower than metal halide lamps, xenon lamps, ultra-high pressure mercury lamps and mercury xenon lamps. For this reason, the radical reaction by the oxygen molecule in air is easy to be inhibited, and the problem that the surface hardenability of the apply | coated resin resulted in remarkably worse compared with the conventional system arises.

<Example>

Next, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to these Examples. In the following description, unless otherwise specified, "%" indicating an oxygen concentration represents a volume concentration (vol%) and "part" represents "mass part". In addition, Me and E represent a methyl group and an ethyl group, respectively.

Production Example 1

(Production of UV-sensitive organopolysiloxane)

The radical polymerization type ultraviolet curable resin used for the Example mentioned later was manufactured. 571 g of organopolysiloxane represented by the following general formula (1) and 2-hydroxy-1-acryloyloxy-3-methacryl to a 1,000 ml reaction vessel equipped with a stirring device, a reflux cooler, a dropping funnel, and a dry air inlet machine. 47 g of yloxypropane (brand name: NK ester 701-A, manufactured by Shin-Nakamura Kagaku Kogyo Co., Ltd.), 200 ml of toluene, 26 g of triethylamine, and 2,000 ppm of dibutylhydroxytoluene were added as a polymerization inhibitor. It heated up at 70 degreeC, stirring, and heated for 7 hours. Thereafter, the mixture was left to cool, 4 g of propylene oxide was added to the filtrate obtained by filtration, and the mixture was stirred at room temperature of 20 ° C for 1 hour. Thereafter, stripping was performed at 100 ° C / 30 mmHg to obtain a transparent oily organopolysiloxane represented by the following formula (2).

Production Example 2-

(Manufacture of radical polymerization type ultraviolet curable resin)

2 parts of 2-hydroxy-2-methyl-1-phenylpropan-1-one, 100 parts of organopolysiloxane synthesized in Preparation Example 1, 1 part of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, One part of triallyl isocyanurate silicone-modified compound represented by the following formula (3) and 0.1 part of the titanium chelate titanium compound represented by the following formula (4) were mixed to obtain a radically polymerized ultraviolet curable organopolysiloxane composition.

The obtained composition was used for the following examples and comparative examples.

Example 1

After applying the ultraviolet curable resin composition manufactured by the manufacture example 2 on the glass plate in the shape of thickness 0.2mm, width 10mm, and length 200mm, and forming a film, the ultraviolet irradiation apparatus (1) which shows this glass plate in FIG. Loaded on the support (2). The ultraviolet irradiator 7 was moved once in the longitudinal direction (direction of arrow 9) of the coating 4 at a rate of 80 mm / sec to irradiate and harden the coating 4. Oxygen concentration of the surface of the film 4 during an operation is the oxygen concentration meter (LC-800, Toray Engineering Co., Ltd. product) which collected the gas collected by the gas collection tube which opened the tip at the position of 0.5 cm from the surface of the film 4 ), And the flow rate of the nitrogen gas introduced from the inert gas supply pipe was adjusted so that the measured value was 1%.

Example 2-

The film was cured in the same manner as in Example 1 except that the oxygen concentration in the vicinity of the resin composition film 4 was controlled to 3%.

Example 3-

The film was cured in the same manner as in Example 1 except that the oxygen concentration in the vicinity of the resin composition film 4 was controlled at 5%.

Example 4

The film was cured in the same manner as in Example 1 except that the moving speed of the ultraviolet irradiator 7 was changed from 80 mm / sec to 100 mm / sec.

Example 5-

The film was cured in the same manner as in Example 1 except that the moving speed of the ultraviolet irradiator 7 was changed from 80 m / sec to 60 m / sec.

Comparative Example 1

When the resin composition film 4 was cured, the film was cured in the same manner as in Example 1 except that the inert gas was not introduced from the gas supply pipe 9 and the atmosphere around and inside the irradiation apparatus was not particularly manipulated. .

Comparative Example 2-

The film was cured in the same manner as in Example 1 except that the oxygen concentration in the vicinity of the resin composition film 4 was controlled to 10%.

Comparative Example 3-

Irradiating the ultraviolet-ray for 2 seconds while moving the ultraviolet-curable resin film at a speed of 80 mm / sec in a conveyor furnace equipped with a conventional metal halide mercury lamp, etc. instead of the ultraviolet irradiation device shown in FIG. A film was cured in the same manner as in Example 1 except for the above.

-Assessment Methods-

In order to evaluate the hardening state of the cured film obtained by the said Example and comparative example, the surface state was evaluated by the finger tactile method and adhesive force measurement.

[Finger tactile evaluation]

When the fingertip touched the surface of the cured film, it was tested whether fingerprints remained on the cured film surface or resin adhered to the finger. Residual fingerprints and resin adhesion were divided into the following three steps.

(Circle): A fingerprint did not remain on the hardened | cured material surface, and resin did not adhere to a finger.

(Triangle | delta): Although the fingerprint remained on the hardened | cured material surface, adhesion of resin did not arise to a finger.

X: The fingerprint remained on the hardened | cured material surface, and resin adhered to the finger.

[Surface adhesive force]

Adhesion was measured by the adhesive force tester (brand name: Polychem Frogtech Tester, Toyo Seiki Seisakusho Co., Ltd.) in three places separated from each other on the cured film surface.

The evaluation and measurement results are shown in Table 1 below.

Fig. 2 is a graph of the relationship between the oxygen concentration in Table 1 and the adhesive force (average value at three positions) (except that the oxygen concentration is changed to 15% or 22% in Example 1, In the same manner to supplement the result obtained when the resin film was cured).

From the results shown in Table 1 and FIG. 2, and from the results of Examples 1 to 5 of the present invention and Comparative Example 3 using the conventional ultraviolet irradiation device, a curing method and ultraviolet irradiation device using the light emitting diode of the present invention. According to the present invention, it was found that the same curability as in the case of using a conventional apparatus is obtained. Moreover, from the comparative examples 1 and 2, it turned out that it is indispensable to control the oxygen concentration on the surface of an ultraviolet curable resin to 5% or less in the hardening method of this invention in order to acquire favorable sclerosis | hardenability.

According to the hardening method of the ultraviolet curable resin of this invention mentioned above, sclerosis | hardenability reliability improves and it can manufacture a high reliability flat panel. In addition, these methods can be carried out by the above-described inexpensive, low power consumption, long life, and small ultraviolet irradiation device.

Claims (11)

A method of irradiating ultraviolet curable resin with ultraviolet rays to cure the resin, using a light emitting diode as a light source of the ultraviolet ray, and maintaining an oxygen concentration at the surface of the ultraviolet curable resin at 5% or less during ultraviolet irradiation. Curing method of ultraviolet curable resin The curing method according to claim 1, wherein an oxygen concentration at the surface of the resin is maintained at 5% or less by introducing an inert gas around the surface of the ultraviolet curable resin. The hardening method of Claim 1 or 2 in which the said ultraviolet curable resin was formed in the film form on the board | substrate for sealing the electronic component provided in the board | substrate. The curing method according to claim 3, wherein the ultraviolet rays emitted from the light emitting diodes are moved to be scanned onto the coating in accordance with the shape of the resin coating. The electronic component provided on the board | substrate was coat | covered with the film | membrane of ultraviolet curable resin, and this resin film is irradiated with the ultraviolet-ray from a light emitting diode, and this resin film is hardened | cured in the state which kept the oxygen concentration in the resin surface below 5%. The manufacturing method of the flat panel containing the thing. The method of manufacturing a flat panel according to claim 5, wherein the ultraviolet rays emitted from the light emitting diodes are moved so that the ultraviolet rays are scanned onto the coating in accordance with the shape of the resin coating. Support for supporting the object, Means for irradiating ultraviolet light to the target object having a light source comprising a light emitting diode, and Means for controlling the oxygen concentration on the surface of the object by supplying an inert gas around the object Ultraviolet irradiation apparatus for the to-be-processed object characterized by including the. 8. The processing target according to claim 7, wherein the processing target object is an object to be coated on a substrate in a film form. And an irradiation light moving means for moving the ultraviolet rays irradiated to the object to be scanned so that ultraviolet rays are scanned onto the film-like object to be processed. The ultraviolet irradiation according to claim 7 or 8, wherein the ultraviolet irradiation means includes a plurality of light emitting diodes arranged in one row or two rows or more in a state of being arranged in one plane or curved shape. Device. The ultraviolet irradiation device according to claim 7 or 8, further comprising means for adjusting a distance between the light emitting diode and the object to be processed. The said oxygen concentration control means is a hood which covered the said ultraviolet irradiation means in the shape of a bell, and the upper part was clogged and the lower part was opened, and the inert which is connected to the hood, and supplies an inert gas into the hood. An ultraviolet irradiation device having a gas supply pipe.

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