JP2005275201A - Manufacturing method of polymer having optical controllability, and optical control film/sheet using polymer obtained by the manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a polymer, where a light source of light from a UV area to a visible area or to an IR area is usable, and the width of the selectable optical performance is wide, and also, easily controllable, and a light-weight, large-sized film/sheet can be formed, and also, which is improved in productivity, and to provide an optical control film/sheet using the polymer obtained by the manufacturing method. <P>SOLUTION: The optical performance is made controllable by heating the active energy ray polymerization composite up to 100 to 150°C, thereafter, irradiating the composite with active energy rays from a selected prescribed direction and polymerizing/hardening the composite. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a polymer having light controllability, and a light control film or sheet using the polymer obtained by the production method. More specifically, the present invention relates to a polymer having a refractive index difference therein. The present invention relates to a production method and a light control film or sheet using a polymer obtained by the production method.

  Many light control plates that scatter light at a predetermined angle have been developed so far (see, for example, Patent Documents 1 to 5). The light control plate described in these patent documents contains two or more kinds of photocurable monomers or oligomers having different refractive indexes, or has a refractive index difference of 0.01 or more before and after curing. The refractive index is controlled by adopting the conditions. For this reason, the techniques described in Patent Documents 1 to 5 have certain limitations on the curable monomers or oligomers that can be used. Therefore, there is a problem that the range of optical performance that can be selected is narrow and difficult to control, and that an appropriate monomer cannot be selected in a field where heat resistance and adhesiveness are required.

On the other hand, hologram screens using photocurable monomers that have been subjected to interference exposure with laser light have been developed as recent advertising media (see, for example, Patent Documents 6 and 7). Laser light is used in the hologram screen, and in the case of a large area screen, a high-power laser light source is required. However, in the conventional screen manufacturing method, it is difficult to control the optical characteristics of the large screen to be manufactured, so a high-power laser is required in proportion to the size of the screen area. There was a problem of cost.
JP-A 63-309902 (Claims, Examples) Japanese Patent Laid-Open No. 1-40905 (Claims, Examples) JP-A-1-77001 (Claims, Examples) JP-A-3-107901 (Claims, Examples) JP-A-3-107902 (Claims, Examples) JP 2000-19635 A (Claims) JP 2000-39672 A (Claims)

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to use a light source from the ultraviolet region to the light in the visible region or infrared region, and has a wide range of optical performance that can be selected. And a method for producing a polymer that is easy to control, lightweight, capable of forming a large-area film or sheet, and excellent in productivity, and a light control film comprising a polymer obtained by the production method, or To provide a sheet.

  As a result of intensive studies to solve the above problems, the inventors of the present invention irradiate active energy rays from a predetermined direction in a state where the temperature of the active energy ray polymerizable composition has been raised, thereby providing a refractive index inside. Thus, the inventors have found that the optical characteristics can be controlled by adjusting the irradiation angle of the active energy ray, and reached the present invention.

  That is, an object of the present invention is to increase the temperature of an active energy ray-polymerizable composition to 100 to 150 ° C., and then irradiate active energy rays from a specific direction to polymerize and cure the composition. This is achieved by a method for producing a polymer having controllability.

  In the production method of the present invention, an active energy ray polymerizable composition containing (meth) acrylate having an unsaturated bond in the molecule can be used as the composition.

  In the production method of the present invention, a composition represented by the following general formula (1) is preferably used as the (meth) acrylate.

However, in the general formula (1), R ¹ and R ² are each independently hydrogen or a methyl radical, n is an integer selected from 2-4.

  Another object of the present invention is achieved by a light control film or sheet using the polymer obtained by the production method of the present invention.

  According to the present invention, light from the ultraviolet region to the visible to infrared region can be used, the range of optical performance that can be selected is wide and easy to control, lightweight, and can form a large-area film or sheet, It is possible to provide a method for producing a polymer excellent in productivity and a light control film using the polymer.

  Hereinafter, the light control film or sheet using the production method of the present invention and a polymer obtained by the production method will be described in detail with reference to the drawings as appropriate.

  The active energy ray-polymerizable composition used in the present invention is a composition containing a monomer or oligomer that can be cured by active energy rays. The monomer or oligomer is not particularly limited as long as it is a monomer or oligomer that can be polymerized and cured by light irradiation to form a transparent polymer, and can be arbitrarily selected from a wide range. Preferably, a monomer or oligomer that is liquid at room temperature is used. Among them, as the monomer or oligomer, it is preferable to use a (meth) acrylate compound having an unsaturated bond in the molecule, and a bifunctional or more polyfunctional (meth) acrylate compound having two or more unsaturated bonds in the molecule. It is more preferable to use a compound, and it is most preferable to use a bifunctional or higher polyfunctional acrylate compound.

  Specifically, the (meth) acrylate is preferably a composition having a structure represented by the following general formula (1).

In general formula (1), R ¹ and R ² are each independently hydrogen or a methyl group, preferably R ¹ and R ² are methyl groups. Moreover, in general formula (1), n is an integer chosen from 2-4, Preferably it is 1.

Specific examples of the (meth) acrylate compound include, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol in which 4 or more ethylene glycol units are continuous, propylene glycol, polypropylene glycol, 1,3-butylene glycol, hexanediol. Neopentyl glycol, 2-hydroxy-1,3-propylene glycol, 2,2-bis (p-hydroxyphenyl) propane, 2,2-bis (p-ethoxyphenyl) propane, p-bis (ethylthio) xylene, m-bis (ethylthio) xylene, p-bis (ethylthio) -2,3,5,6-tetrachloroxylene, 4,4′-bis (ethoxy) diphenyl sulfide, 4,4′-bis (ethoxy) diphenylsulfone , 4, '-Bis (ethylthio) diphenylsulfide, 4,4'-bis (ethylthio) diphenylsulfone, 4,4'-bis (ethylthio) diphenylketone, 2,4'-bis (ethylthio) diphenylketone, 4,4'- Bis (ethylthio) -3,3 ′, 5,5′-tetrabromodiphenyl ketone, β, β′-bis (phenylthio) diethyl ether, β, β′-bis (phenylthio) diethylthioether, trimethylolpropane and the like ( Poly) ols and ester compounds of acrylic acid or methacrylic acid, urethane acrylates, epoxy acrylates and the like.
In the present invention, a compound selected from di (meth) acrylates having a small molecular weight is preferable, and ethylene glycol methacrylate is particularly preferably used.

  Although the said monomer or oligomer component can also be used independently, it can also be used in combination of 2 or more.

  The active energy ray-polymerizable composition used in the present invention can be cured by irradiating the above-mentioned monomer or oligomer component with active energy rays in the presence of a photopolymerization initiator. In the present invention, known photopolymerization initiators can be used. For example, when an acrylic monomer is cured, a photo radical generator can be used as a photo polymerization initiator. As the photoradical generator, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, trimethylbenzoylphenylphosphinic acid methyl ester, 1-hydroxycyclohexyl phenyl ketone, benzophenone, diphenoxybenzophenone and the like can be used. A photoinitiator may be used independently or may use 2 or more types together. The concentration of the photopolymerization initiator is not particularly limited, but is 0.0001 to 10 mol%, preferably 0.001 to 1 mol%, more preferably 0.01 to 0, based on the mass of the active energy ray polymerizable composition. .1 mol%.

  In the present invention, the polymer having light controllability is based on a liquid monomer or oligomer composition for polymerization in which the monomer or oligomer and the photopolymerization initiator are mixed (that is, an active energy ray polymerizable composition). After being applied on the material or shaped in a mold, it is heated to 100 to 150 ° C., and then irradiated with active energy rays from a selected specific direction for polymerization. The base material used for forming the polymer having light controllability is not particularly limited, and various base materials such as glass and plastic can be used. Moreover, when shaping | molding a liquid monomer or oligomer composition, it is preferable to shape in transparent casting molds, such as glass and a plastics.

The manufacturing method of the present invention will be described below with reference to FIGS.
FIGS. 1-4 show the manufacture example of the optical component which consists of a polymer which has light controllability of a sheet | seat or a film form. Reference numeral 2 is an active energy ray polymerizable composition (hereinafter abbreviated as “composition”), reference numerals 3 and 5 are transparent supports, reference numeral 4 is a frame spacer, reference numeral 6 is a light source, reference numeral 7 is an object to be measured, reference numeral Reference numeral 8 denotes a measuring beam, and reference numeral 9 denotes an incident angle.

  As shown in FIG. 1, the liquid composition 2 is injected into an injection mold facing each other through transparent supports 3 and 5 and a frame-like spacer 4 and then shaped by the injection mold. Above the shaped liquid composition 2, a light source 6 is provided parallel (horizontally) to the upper surface, and the composition 2 is cured by irradiating active energy rays from a selected specific direction. Can do.

As the active energy ray light source 6 used at the time of curing, a diffusion light source can be usually used. At this time, it is preferable to irradiate the upper surface of the shaped composition 2 so that the irradiation angle of light does not change with time. For example, the shaped composition 2 and the light source 6 are fixedly stationary. Irradiation is preferably performed.
In the present invention, light can be irradiated in an inert gas such as nitrogen when the presence of oxygen during the polymerization of the monomer or oligomer inhibits the polymerization.

  The light source 6 for active energy rays can be appropriately selected according to the type of photocurable liquid monomer or oligomer component in the composition and the characteristic wavelength of the photopolymerization initiator. In general, an ultraviolet light source such as a high-pressure mercury lamp, a metal halide lamp, a short arc lamp, or an electrodeless mercury lamp can be used as a point light source or a line light source. When used in combination with a photosensitizer, a visible or infrared light source such as a laser can also be used.

The intensity of the irradiation light of the active energy rays may be determined in consideration of the curing area and the degree of change in refractive index, usually several to several hundreds mW / cm ^2, preferably from 1 to 500 mW / cm ^2, further Preferably it is 5-50 mW / cm < ² >. The irradiation time of the active energy ray can be set in consideration of the monomer or oligomer component in the composition to be cured and the film thickness, but the total irradiation light amount is 1 to 100 J / cm ² even in the lowest illuminance portion of the light intensity distribution. The irradiation time can be determined such that the irradiation time is usually 1 second to 1 hour, preferably 10 seconds to 10 minutes, more preferably 30 seconds to 5 minutes.

  Irradiation of active energy rays can be further divided into a plurality of times. For example, a method of irradiating about 1/20 to 1/3 of the total irradiation amount at the first time and irradiating the necessary remaining amount at the second time or later may be mentioned.

  As shown in FIG. 1, the polymerization curing by irradiation with active energy rays can be irradiated with active energy rays from a light source 6 installed in one direction of the composition 2, but as shown in FIG. Active energy rays can also be irradiated from each of the light sources 6a and 6b installed in two directions. Furthermore, as shown in FIG. 3, when the light sources 6a and 6b are installed in two opposite directions of the composition 2, the light sources 6a and 6b can be arranged so as to face each other perpendicularly to irradiate active energy rays. . Moreover, as shown in FIG. 4, the point light source 6c can be arrange | positioned to one direction facing the composition 2, and an active energy ray can also be irradiated. In that case, the composition 2 produces | generates the part from which a cylindrical refractive index differs as shown in FIG.

  As shown in FIG. 1, the composition 2 that has been irradiated with the active energy rays from the light source 6 starts to be polymerized immediately below the transparent support 5 when photocured to produce a microgel. Since this microgel has a refractive index that is increased by polymerization, a difference in refractive index occurs between the microgel and surrounding uncured monomers, which acts as a kind of lens, and binds the shape of the light source 6 in the composition 2. Image. Since the amount of light at the imaging portion increases, the composition 2 is preferentially polymerized and cured from the portion in the composition 2, and the refractive index increases due to curing shrinkage. On the other hand, since the portion that has not been condensed by the microgel is slowly polymerized and cured, a difference in refractive index occurs between the portion that has been previously polymerized and cured. Thereby, the part from which a refractive index differs arises inside a polymer. In particular, irradiation with active energy rays at a temperature of 90 to 150 ° C. increases the polymerization rate, and the monomer molecules actively move due to thermal vibration, thereby increasing the crosslink density of di (meth) acrylate and increasing the refractive index. Large microgels can be produced.

  In the present invention, the composition is heated in the range of 100 to 150 ° C. during polymerization and curing, but is preferably 100 to 130 ° C., more preferably 100 to 110 ° C. If the temperature at the time of polymerization and curing of the composition is 100 ° C. or higher, a microgel can be generated appropriately, and a lens effect can be generated before the whole is cured. Moreover, if the temperature at the time of polymerization hardening of the said composition is 150 degrees C or less, deterioration of resin will be suppressed and resin will not be colored yellow.

  Since the polymer obtained by the production method of the present invention has a refractive index difference inside the polymer, the optical performance can be controlled. The optical performance is performance based on a difference in refractive index, and in this specification, means performance derived from different transmittances for incident light from different angles. The polymer obtained by the production method of the present invention has, for example, a transmittance of incident light from an angle A of 60% or more, preferably 70% or more, more preferably 75% or more, and an angle B different from A. Can be controlled to 50% or less, preferably 40% or less, and more preferably 30% or less.

  Hereinafter, specific embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples unless it exceeds the gist.

[Manufacturing equipment and manufacturing conditions]
(1) Light source used for polymerization curing reaction A metal halide lamp M01L21 (length: 125 mm, output: 80 W / cm ² , emission wavelength distribution: 220 to 700 nm, energy distribution maximum in the vicinity of 360 to 390 nm) manufactured by LAN Technical Service was used. .
(2) Apparatus used for transmittance measurement An ultraviolet-visible spectrophotometer U-4100 manufactured by Hitachi having a variable angle unit in the sample chamber was used. The wavelength of incident light was 550 nm. As shown in FIG. 5 (A), the spectrophotometer is configured to measure light (incident light) by mounting the object to be measured 7 (plate-like solid sample) on an angle variable unit (not shown). The transmittance when the solid surface has an angle can be measured. Further, as shown in FIG. 5B, the incident angle 9 (θ) of the light with respect to the DUT 7 (plate-like solid sample) is such that the perpendicular direction of the sample is θ = 0 °.

(Example 1)
Ethylene glycol dimethacrylate (manufactured by WAKO) was mixed with 2,4,6-trimethylbenzoyldiphenylphosphine oxide 0.002M as a photoinitiator and stirred until uniform. This was hereinafter referred to as “monomer mixture A”.
Next, on a cover glass (manufactured by MATSANAMI, length 50 mm, width 40 mm, thickness 0.12 to 0.17 mm), a silicon rubber having a thickness of 300 μm was adhered in a frame shape, and as shown in FIG. A 30 mm square injection mold was prepared. The monomer mixture A was poured into an injection mold made of this cover glass and silicon rubber, and the upper surface thereof was covered with the cover glass so that air was not mixed.
Next, the sample was placed 40 cm below a metal halide lamp with a length of 125 mm and an output of 80 W / cm ² , and hot air was blown onto the top surface of the injection type cover glass using a heating gun, so that the temperature of the sample reached 110 ° C. Heated to keep. The temperature of the sample was constantly measured by a thermocouple. Ultraviolet rays were irradiated for 150 seconds under this heating condition.
After the polymerization, the particle-dispersed cover glass was removed, and the incident angle dependence of the transmittance of the sample was measured using the UV-visible spectrophotometer. The results are shown in Table 1.

(Comparative Example 1)
A polymer was produced by the same method as described in Example 1 except that the polymerization was performed under the condition that the sample was heated to 80 ° C. using a heating gun. The results are shown in Table 1.

(Comparative Example 2)
A polymer was produced in the same manner as described in Example 1 except that the polymerization was carried out in a room temperature atmosphere of 20 ° C. without using a heating gun. The results are shown in Table 1.

In the case of the polymer produced by the production method of the present invention from Table 1, the light transmittance at an incident angle of 0 ° is 30%, the light transmittance at an incident angle of 25 ° is 77%, and a good transmittance. Angular dependence was obtained.
In contrast, in the case of the polymer obtained by the method described in Comparative Example 1 (heating temperature 80 ° C.), the light transmittance at an incident angle of 0 ° is 65%, and the light transmittance at an incident angle of 25 °. Was 88%, and a sufficient change in transmittance was not obtained. Further, in the case of the polymer (room temperature 20 ° C.) obtained by the method described in Comparative Example 2, the light transmittance at the incident angle of 0 ° and the incident angle of 25 ° is almost the same, and the change in the transmittance is almost the same. I couldn't see it.
From this, according to the manufacturing method of this invention, it turns out that the polymer (light control film) which controlled the light transmittance by adjusting the incident angle of a light beam is obtained.

  According to the present invention, since a polymer having a refractive index difference is obtained inside, the polymer obtained by the present invention is lightweight, excellent in heat resistance and weather resistance, and is made of a plastic light control film and sheet, particularly privacy. It is useful as a viewing angle limiting filter for protection. The polymer obtained by the production method of the present invention is used as it is as a panel member such as a window glass, an optical component for optical communication, a light control sheet, particularly a viewing angle control sheet or film used for protecting privacy. Can do.

It is drawing (the 1) which shows an example of the manufacturing method of this invention. It is drawing (the 2) which shows an example of the manufacturing method of this invention. It is drawing (the 3) which shows an example of the manufacturing method of this invention. It is drawing (the 4) which shows an example of the manufacturing method of this invention. It is the schematic (the 1) of the method of measuring the transmittance | permeability in the Example of this invention. It is the schematic (the 2) of the method of measuring the transmittance | permeability in the Example of this invention.

Explanation of symbols

2 Active energy ray polymerizable composition 3 Transparent support 4 Frame spacer 5 Transparent support 6, 6 a, 6 b, 6 c Light source 7 Measured object 8 Measurement light beam 9 Incident angle

Claims (5)

Production of a polymer having light controllability, wherein the active energy ray-polymerizable composition is heated to 100 to 150 ° C., and then the active energy ray is irradiated from a specific direction to polymerize and cure the composition. Method. The manufacturing method of Claim 1 using the composition containing the (meth) acrylate which has an unsaturated bond in a molecule | numerator as the said active energy ray polymeric composition. The method for producing a polymer according to claim 2, wherein the (meth) acrylate is a composition represented by the following general formula (1).
In General Formula (1), R ¹ and R ² are each independently hydrogen or a methyl group, and n is an integer selected from 2 to 4. The light control film which uses the polymer obtained by the manufacturing method as described in any one of Claims 1-3. The light control sheet which uses the polymer obtained by the manufacturing method as described in any one of Claims 1-3.