JP2798335B2 - Method for producing paste for optical filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a paste for an optical filter, and more particularly to a method for producing a transparent paste for an optical filter in which fine particles of a metal or a metal compound are dispersed.

[0002]

2. Description of the Related Art At present, an optical filter in which fine particles of various metals or metal compounds are dispersed in a polymer has been developed, and is used for an ultraviolet and infrared absorbing material, a liquid crystal color filter and the like. For example, an infrared absorption filter is mounted on an outer wall of a garage or the like to prevent the temperature inside the garage from rising. This infrared absorption filter is obtained by dispersing copper sulfide powder in a polymer. In this production method, generally, a polymer pellet and a metal sulfide powder are mixed by a tumbler, and the mixture is formed by an extruder.

[0003]

However, fine particles of a metal or a metal compound used in a conventional optical filter have a particle size of 0.1 to 1.0 μm.
If not added in a large amount, there is a defect that the light absorption ability is lacking, and the fine particles are not uniformly dispersed in the matrix but aggregate, so that the light absorption becomes non-uniform. The present inventors have paid attention to such a problem, and have a metal or a metal compound having an extremely small particle diameter, which is a material of a material having excellent light absorbing ability, and a transparent and excellent paste having excellent light absorbing ability. It is intended to provide a manufacturing method.

[0004]

That is, according to the present invention, a polymer layer in a thermodynamically non-equilibrium state is prepared, a metal layer is adhered to the surface of the polymer, and the polymer layer is heated below the melting temperature. By bringing the polymer layer into an equilibrium state, the metal of the metal layer is made finer and dispersed in the polymer layer to produce a polymer composite, and the polymer composite, polymethyl methacrylate,
A transparent polymer selected from carbonate and polystyrene is dissolved in an organic solvent , and the transparent polymer is dissolved in 60
ペ ー ス ト 99.9% by weight of a paste for an optical filter.

[0005] In obtaining the above-mentioned polymer composite, first, the polymer layer is formed into a thermodynamically unstable non-equilibrium state . Specifically, (1) a vacuum deposition method of heating and melting and evaporating a polymer in a vacuum to solidify a polymer layer on a substrate; (2) melting the polymer at a melting temperature or higher;
In this state, it is immediately poured into liquid nitrogen or the like, rapidly quenched, and a melt quenching and solidification method for attaching a high pre-layer on the substrate,
(3) After dissolving the polymer in a solvent (concentration of 60% or less, preferably 20% or less), apply it on a substrate, and keep it at a constant temperature in a closed container while maintaining high speed (240 l / min or more).
There is a high-speed desolvation method in which the solvent is removed by degassing.

In the case of the vacuum deposition method, a vacuum degree of 10 ⁻⁴ to 10 ⁻⁶ Torr and a deposition rate of 0.1 to 100 μm / min, preferably 0.5 to 10 ⁻⁴ Torr using a normal vacuum deposition apparatus. At 5 μm / min, a polymer layer can be obtained on a substrate such as glass. In the melting quenching and solidification method, a polymer is melted and cooled at a rate higher than the critical cooling rate inherent to the polymer to obtain a polymer layer. The resulting polymer layer is placed in a thermodynamically unstable non- equilibrium state and transitions to an equilibrium state over time.

The polymer used in the present invention is, for example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 69, high density polyethylene (HDPE), low density polyethylene (LDPE), polyethylene terephthalate (PET), polyvinyl alcohol. , Polyphenylene sulfide (PPS) and the like.

Subsequently, the thermodynamically unstable polymer layer is transferred to a step of adhering a metal layer to its surface. In this step, the metal layer is deposited on the polymer layer by a method such as vapor deposition of the metal layer on the polymer layer by a vacuum deposition apparatus or by directly attaching the metal plate to the polymer layer. Examples of the material of the metal include gold, silver, copper, iron, nickel, cobalt, tin, zinc, yttrium, indium, cadmium, chromium, cobalt, titanium, lead, palladium , and manganese, and are not particularly limited.

The composite in which the metal layer and the polymer layer thus obtained are in close contact with each other is heated to bring the polymer layer into an equilibrium state. In this step, the polymer layer with the metal layer is heated in a thermostat at a temperature not higher than the melting temperature of the crystalline polymer. As a result, the metal of the metal layer has a particle size of 1,000 nm or less, preferably 300 nm or less, more preferably 100 nm or less.
It becomes fine particles of metal or metal oxide of nm or less and diffuses and penetrates into the polymer layer, and this state continues until the polymer layer is completely relaxed, and the thickness of the metal layer attached to the polymer layer also decreases. Decreases and eventually disappears. Therefore, in order for the entire metal layer to become fine particles of metal or metal oxide and be dispersed in the polymer layer, it is necessary to adjust the thickness thereof. The fine particles are composed of the metal, Cu ₂ O, Fe ₃ O ₄ , Zn
It contains metal oxides such as O, TiO, and NiO.

[0010] When the polymer layer is heated in this step, the polymer layer exhibits a unique coloring due to the interaction with the metal or metal oxide fine particles, and the metal or metal oxide fine particles enter the polymer layer. You can see that it has penetrated. Also, this color can vary depending on the type of metal or metal oxide, the particle size of the metal or metal oxide, and the type of polymer. In the polymer composite thus obtained, fine particles are separated and dispersed in an independent state. Further, after the polymer composite is dispersed without aggregating the ultrafine particles of the metal or metal oxide obtained by the above method in the polymer layer,
The ultrafine particles obtained by heat-treating such a polymer layer at a temperature of 200 ° C. or lower in a sulfur vapor or H ₂ S atmosphere may be used. When the temperature exceeds 200 ° C., the polymer layer starts to deteriorate. The obtained sulfide is, for example, CuS, C
dS, ZnS and the like are included.

The polymer composite is a transparent polymer such as polymethyl methacrylate, polycarbonate,
Alternatively, it is dissolved in an organic solvent together with polystyrene or the like.
In this case, the amount of the transparent polymer added is 60 to 99.9% by weight. If the addition amount is less than 60% by weight, the amount of the polymer (for example, crystalline polymer) in the polymer composite increases, and the obtained paste starts to become cloudy and lacks light absorption ability. come. On the other hand, the addition amount is 99.9% by weight.
When the ratio exceeds, the content of the metal or the metal compound decreases, and the light absorbing ability is lacking. This melt is a viscous liquid paste, which is applied to a substrate and a solvent is evaporated to form a coating film, or after pouring into a mold, the solvent is evaporated to form a thin film optical paste. You can get a filter. In the paste, the metal or metal compound in the form of fine particles is surrounded by the polymer which is the matrix, and is dispersed without being aggregated in the transparent polymer.

The organic solvent used here is dichloromethane, meta-cresol, dimethylformaldehyde, formic acid or the like. In the case where meta-cresol is used, the paste may be discolored due to long-term storage and the light absorbing ability may be deteriorated. Therefore, it is better not to use this positively.

[0013]

Next, the present invention will be described in more detail with reference to specific examples. Example 1 First, nylon 11 was put into a tungsten board by a vacuum evaporation apparatus, and the pressure was reduced to 10 ^-6 Torr. Then
A voltage is applied between the electrodes and the tungsten board is heated in a vacuum to melt the polymer, and 10 ^-4 to 10 ^-6 Torr is placed on a base (glass plate) placed on the mounting base.
A polymer layer as a vapor-deposited film having a thickness of about 5 μm was obtained at a rate of about 1 μm / min at a degree of vacuum. The molecular weight of the polymer layer is about 1/2 to 1/10 that of the pellet. Further, copper is wound around a tungsten wire and melted by heating to 10 ^-4.
Vapor deposition is performed under a vacuum of -10 ^-6 Torr, a copper vapor deposition film is deposited on the polymer layer, and the glass plate with the laminated film is taken out of the vacuum deposition device and placed in a thermostat kept at 120 ° C. For 10 minutes to obtain a composite. The fine particles in the obtained polymer composite were Cu ₂ O, the particle size was 5 nm, and the content was 42.9% by weight.

Subsequently, the obtained polymer composite is placed in a reduced-pressure vessel, and sulfur is put therein so as not to come into contact with the polymer composite, and sulfur is added at 150 ° C. under a reduced pressure of 10 ⁻¹ Torr. 6
Sulfurization treatment was performed with sulfur under heat treatment conditions of 0 minutes. The obtained polymer composite was measured for the X-ray diffraction pattern of the same sample using a thin-film X-ray diffractometer (RINT1200, manufactured by Rigaku Denki) having an incident angle of 0.5 °, and the particle size of the fine particles was determined by X-ray diffraction. The content was calculated from the half width of the peak by Scherrer's formula, and the content was determined from the ash content after removing organic substances in air at 1000 ° C. for 30 minutes. The fine particles in the obtained film were CuS, the particle size was 45 nm, and the content was 52.6% by weight.

The above-mentioned polymer composite and polymethyl methacrylate are mixed with methylene chloride so that the added amount of polymethyl methacrylate is 98% by weight and CuS is 1% by weight, and the mixed solution is molded. , And the solvent was removed at room temperature to produce a film. The visible to near-infrared absorption characteristics of the film containing CuS were measured using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation). The result is shown in FIG. According to this, since the particle diameter of CuS was small, light in the visible region was transmitted and light in the near infrared region was absorbed.

Comparative Example 1 CuS having a particle size of 10 to 80 μm and polymethyl methacrylate were mixed with methylene chloride so that the added amount of polymethyl methacrylate was 99% by weight and CuS was 1% by weight. The solution was poured into a mold and the solvent was removed at room temperature to produce a film. The obtained film was measured for visible to near-infrared absorption characteristics using the same ultraviolet-visible spectrophotometer as in Example 1. The result is shown in FIG. According to this, since in the comparative example large particle size of CuS powder, also not uniformly dispersed, the light also does not absorb the light were scattered for all wavelengths.

Comparative Example 2 The polymer composite obtained in Example 1 and polyethylene were
98% by weight of polyethylene, 1% by weight of CuS
Was mixed using methylene chloride so that the mixture was poured into a mold, and the solvent was removed at room temperature to prepare a film. The obtained film was cloudy, and the visible to near-infrared absorption characteristics of the film were measured with the same ultraviolet-visible spectrophotometer as in Example 1. As a result, no light was absorbed, and light was scattered at all wavelengths. I was

[0018]

As described above, according to the present invention, since a metal or a metal compound having a very small particle diameter can be contained in a transparent polymer, a paste for an optical filter which is transparent and has excellent light absorbing ability can be obtained. Can be.

[Brief description of the drawings]

FIG. 1 shows the visible to near-infrared absorption characteristics, which are the relationship between the wavelength and the absorbance of the films obtained in Example 1, Comparative Examples 1 and 2.

Continuing from the front page Examiner Masaaki Moriuchi (56) Reference JOURNAL OF MATERIAL ALS SCIENCE LETTER S, 10, P. 477-479 (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 5/20-5/22

Claims (1)

(57) [Claims] 1. A polymer layer in a thermodynamically non-equilibrium state is prepared, and a metal layer is brought into close contact with the surface of the polymer, and then heated at a temperature lower than the melting temperature to shift the polymer layer to an equilibrium state. it the metal of the metal layer with fine particles dispersed in the polymer layer in to prepare a polymer composite, the polymer composite and polymethyl
Methacrylate, polycarbonate, and polystyrene
And a transparent polymer selected from the group consisting of
A method for producing a paste for an optical filter, comprising adding 60 to 99.9% by weight of a transparent polymer .