JP2565371B2 - Functional polymer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a functional polymer sheet, and more particularly to a functional polymer sheet having a remarkably enhanced required function.

(B) Conventional technology A functional polymer sheet is a polymer sheet having various physical functions such as conductivity, photoconductivity, catalytic property, adsorptive property, and bactericidal property, or a chemical function, Usually, the polymer sheet has a structure in which a powder substance having at least one of these functions is carried.

Generally, in the functional polymer sheet, in order to exert the functionality, it is necessary that the powder substance having the above-mentioned functionality is exposed on the surface of the sheet. Also,
In order to maximize the effectiveness of expensive powder substances,
In order to enhance the functionality, it is desired that such a powder substance does not exist inside the sheet and is fixedly arranged on the entire surface as much as possible.

By the way, the following methods have been proposed as a method for supporting the functional powder substance on the polymer sheet. That is,
Roll forming after mixing a polymer material and a functional powder substance, a method of forming a sheet by extrusion molding, etc., prepare a porous polymer sheet having open cells on the surface,
A method of filling the open cells of this sheet with a functional powder substance, or fixing the functional powder substance to the surface of a polymer sheet, cloth or paper not containing the functional powder substance using a binder such as an adhesive. Functional polymer sheets have been proposed.

And, in the above, as disclosed in JP-A-57-67667, the porosity-imparting material of the coating film is dispersed in a self-cleaning coating material prepared by blending a catalyst powder with an inorganic heat-resistant coating material. In Europe, a coating surface for self-cleaning has been proposed in which the wall surface is coated to form a coating. In this case, silicone varnish or a mixture of silicone varnish / methanol is used as the porous material for this coating. There is.

(C) Problems to be Solved by the Invention However, in the above, the polymer material and the functional powder substance are uniformly mixed and formed into a sheet, or
In the above-mentioned materials, since the functional powder substance is packed in the open cells, it is difficult to carry a large amount of the functional powder substance only on the surface of the sheet.

By the way, a particularly disadvantageous problem of the functional powder substance existing inside the sheet is that the light-sensitive functional powder substance, for example, a photoreactive catalyst functional powder substance, does not transmit light to the inside of the sheet. Economic loss is increased because the function, for example, the catalytic action is not developed.

Further, in the above, there are products represented by polishing sheets.

Although a large amount of powder is exposed on the surface of this sheet, the functional powder substance is covered with the adhesive because it is applied to the polymer sheet with a mixed system of abrasive powder and adhesive in the manufacturing method. As a result, some parts of the function are disqualified.

Particularly, in the coating surface for self-cleaning disclosed in JP-A-57-67667, a silicone varnish or a mixture of silicone varnish / methanol is used as the porous material of the coating film, and the porous layer is formed by drying and curing. However, there are the following problems.

In other words, this product has a constitution in which a catalyst powder is mixed with an inorganic heat-resistant paint, and further a porosification material (varnish) is dispersed in this paint "including a base polymer (vehicle)."
Since this is dried and cured, not only the catalyst powder, but also the non-catalyst material such as the inorganic material and the porosification material are similarly distributed on both the surface and the inside of the coating film. Materials other than the catalyst powder coat the surface of the catalyst powder, and the degree of exposure of the catalyst powder becomes extremely low, so that the function as a catalyst cannot be sufficiently exhibited.

In particular, the catalyst powder is coated with the base polymer (vehicle) in the paint, the porosifying material, and the inorganic material,
In addition to the catalyst powder being isolated, as a result of the inorganic material or the porosifying material hindering the light transmission, for example, the physical function such as photoconductivity and photolysis catalyst can hardly be exhibited, and the reliability is lacking. There is a fatal issue.

Further, with the above, it becomes difficult to allow a large amount of the functional powder substance to be present on the surface of the sheet, so that the functionality of the functional powder substance is hindered by the polymer material. Therefore, in order to fully express the functionality of the functional powder substance, it is necessary to expose the functional powder substance at a high density on the sheet surface, and for this reason, it is necessary to mix a large amount of the functional powder substance. This, however, has a problem that the strength of the sheet is remarkably reduced, and the functional powder substance is still not exposed so that the sheet does not exhibit a sufficient function.

Further, in the above-mentioned one, it is possible to fill the open cells with a large amount of the powder substance to obtain a highly functional one, but the fixing property between the functional powder substance and the polymer material as the base material is poor. As a result, if the functional powder substance falls off during handling, cutting, processing, etc. of the sheet, looseness occurs between the filled powder substances, and as a result, the dropout of the powder substance increases sharply. I have a problem. Therefore, it is not suitable for dynamic applications involving movement such as functional vibration,
There is a drawback that the range of use is limited to static applications that do not involve such operations.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a functional polymer sheet that can exhibit various functions of a functional powder substance sufficiently and is versatile. It is a thing.

(D) Means for Solving the Problems The inventors of the present invention have made earnest studies to solve the above problems, and as a result, have found that particles of the functional powder substance (primary particles or particles close to the primary particles). It was found that when the secondary particles) are arranged and fixed only on the surface of the polymer sheet without interposing foreign matter, the function of the functional powder substance is sufficiently exhibited, and the present invention has been completed. .

That is, in the functional polymer sheet according to the first claim of the present application, the functional powder substance does not exist at all inside the polymer sheet, and the functional powder substance is present on the surface of the preformed sheet and the foreign matter is present in the sheet. It is characterized in that it is arranged and fixed without being arranged.

The polymer sheet used in the present invention is not particularly limited, but it is a preformed film or a sheet-like body, and specifically, polyester, polyimide, epoxy resin, polytetrafluoroethylene ( Hereinafter, a fluorine-based polymer material such as PTFE), polyamideimide, polyvinyl chloride, polyethylene, polystyrene, acrylic resin and the like can be used.

In this case, it is a polymer sheet mixed with glass fiber, carbon powder or the like in order to have the strength of the sheet itself or the characteristics such as weather resistance, regardless of the functional powder substance described later. Can also be used.

Further, as the functional powder substance used in the present invention,
A substance that is not compatible with the polymer sheet, or a substance that does not react with the polymer sheet and that is electrically conductive, photoconductive, catalytic,
It has one or more functions of adsorptivity, bactericidal property, etc., and is not particularly limited to an inorganic substance or an organic substance. It is also possible to use two or more kinds of powder substances having such a function in combination.

For example, carbon powder, zinc oxide powder, rutile titanium oxide type powder, tin oxide, etc., are powder materials having conductivity, photoconductive cadmium sulfide, zinc oxide, etc., and titanium oxide, silver, etc. are catalytically active. Zeolite, activated carbon and the like are adsorbent, and iodoform and the like are bactericidal.

The feature of the present invention resides in that the functional powder substance is arranged and fixed on the surface of the polymer sheet without interposing foreign matter.

Thus, in order to fix the functional powder substance on the surface of the polymer sheet in an array, the following means may be taken.

That is, the polymer sheet may be a sheet prepared in advance, and it is not necessary to use any special sheet.

That is, a polyimide sheet may be selected if heat resistance is required, and a PEFE sheet or the like may be selected if it is chemical resistance, if desired. The surface treatment of such a sheet is performed so that the sheet surface has a hydrophobic or hydrophilic characteristic.

Examples of the surface treatment method include means such as sputtering, corona discharge, and various surface treatments such as chemical oxidation.

As a method of performing the above-mentioned sputtering treatment, for example, it is already known as described in Japanese Patent Publication No. 53-31827, and a high frequency voltage is applied between the negative and positive electrodes in a pressure-resistant container under a reduced pressure atmosphere. Then, in the dark portion of the cathode where the ion energy in the discharge region is large, the negative ions generated by the discharge are accelerated and collided with the surface of the molded article on the cathode for processing.

A device for this purpose is configured such that a cathode and an anode are arranged to face each other in a pressure resistant container, the cathode is connected to a high frequency power source through an impedance matching device, and the anode is connected to a ground portion of the high frequency power source.

A shield electrode is provided outside the cathode and kept at the ground potential.

The surface treatment of the sheet base material (polymer material) can be carried out batchwise or continuously depending on the device.

 The sputtering process is usually performed at room temperature.

The frequency of the high frequency power used is hundreds of KHz to tens of MHz.
However, it is convenient to use the industrially assigned frequency of 13.56 MHz in practice.

The distance between the electrodes is determined in proportion to the reciprocal of the square root under the sputtering treatment atmosphere. For example, when the atmospheric pressure is 0.005 Torr, it is 30 mm or more.

As the atmosphere, air or water vapor is usually used, but in addition to this, an inert gas such as nitrogen, argon, helium, or carbon dioxide can also be used.

Then, in order to perform the sputter etching treatment on the surface of the sheet base material (polymer material), specifically, 0.0005 to 1 Tor
Under an atmosphere pressure of r, the discharge treatment amount defined by the product of the treatment electrode density and the treatment time is 0.1 to 200 watt · sec / cm ² , preferably 1 to 180 watt · sec / cm ² .

In such a surface treatment, it is possible to treat both surfaces in some cases when it is necessary to have functionality on both surfaces.

Next, a dispersion liquid in which the functional powder substance is dispersed in a solvent is applied to the treated surface of the sheet, and the solvent of the dispersion liquid is dried and removed.

In this dispersion, the functional powder substance or the solvent having a high affinity for the polymer can be appropriately selected and used.

However, this dispersion liquid is a non-volatile liquid or a third liquid containing an adhesive that inhibits the function of the functional powder substance.
It is a dispersion of a functional powder substance and a volatile solvent (dispersant), without the addition of a substance.

Moreover, various coating methods such as a general depping method and a bar coating method are adopted as the method for coating and drying the dispersion liquid, and the drying method is not limited as long as the dispersant can be removed.

The coated and dried sheet is in a state where the functional powder substance is temporarily fixed on the surface of the polymer sheet.

Therefore, in order to arrange and fix the functional powder substance on the surface of the sheet completely without intervening foreign matter, pressure bonding with a roll is performed.

At this time, the roll temperature is preferably equal to or higher than the glass transition point of the polymer sheet (hereinafter referred to as Tg), but may be Tg or lower depending on the characteristics of the functional powder substance, or the arrangement of the functional powder substance by roll pressure bonding at room temperature, It can be fixed, and if the support of the functional powder substance on the polymer sheet is good only by coating and drying, it may be possible not to press the roll.

With this structure, the functional powder substance is arranged and fixed only on the surface of the sheet without interposing foreign matter on the sheet.

In using the functional polymer sheet thus formed, the functional powder substance is arranged on the surface of the sheet, and the powder substance is further adhered to and fixed on the sheet surface. When there is a problem in application, it is possible to immerse the sheet in ultrasonic waves in water to remove excess functional powder substance. On the contrary, when there is a concern that excess powder may fall off the sheet, roll pressure bonding may be repeated.

Further, in the constitution of the present invention, when a slight problem occurs where surface friction occurs, overcoating with a resin or the like is possible, but in this case, it is possible to prevent the various functions of the functional powder substance from being lost. It is important that the functional powder substance is arranged and fixed on the surface of the molecular sheet without interposing foreign matter on the sheet.

The functional polymer sheet of the present invention may be used for an application based on the functional characteristics expressed by the functional powder substance itself, or for an application in which the characteristics of the function are modified, for example, a drug-retaining agent for medical use. It can also be used as a release sheet or a sheet for immobilizing bio-related enzymes.

Further, in the functional polymer sheet according to claim 2 of the present application,
The one using a manganese dioxide or titanium oxide-platinum-based catalyst whose functional powder substance is a catalyst has a wide industrial application from the viewpoint of the catalytic function and economic efficiency of manganese dioxide, or titanium oxide. -Platinum-based catalysts have a very high catalytic ability, and since they are fine particles, it is extremely difficult to handle them by their nature. It expands significantly.

(E) Action As described above, in the functional polymer sheet according to the present invention,
Since the powder substance having the functionality on the surface of the sheet is arranged and fixed on the sheet without interposing a foreign substance, high functionality can be exhibited.

Moreover, since the functional powder substance is fixed to the surface of the sheet without interposing foreign matter on the sheet, mechanical properties such as flexibility, flexibility, and strength are secured, and mechanical vibration is involved. It has the effect of obtaining a versatile material that can be used in dynamic locations.

(F) Examples Hereinafter, the present invention will be described in detail based on Examples.
The present invention is not limited to this.

Example 1 Polytetrafluoroethylene (cutting PTFE sheet having a thickness of 100 μm) was used as a polymer sheet, and the surface of this sheet was first subjected to a sputter hydrophilic treatment.

The sputtering process condition is 8 w · sec / cm ² .

Further, titanium oxide (TiO ₂ · rutile type) was used as the functional powder substance, and this was adjusted to a concentration of 9% by weight with water.

The total amount of this adjustment liquid was 50 g, and the dispersion liquid was made into a uniform dispersion liquid in an ultrasonic disperser (Sharp DT-52) for 30 minutes.

This dispersion was dropped onto the sputtered area (30 mm × 50 mm) of the polymer sheet.

At this time, in order to prevent deformation of the polymer sheet, both ends of the sheet were fixed with clips.

Spread the dropped dispersion so that it wets the entire surface with a glass rod, and then keep this sheet at the temperature with clips attached.
Place on a hot plate heated to 190 ° C to evaporate the water in the dispersion,
It was completely dried.

The sheet thus obtained has only TiO ₂ temporarily attached to the surface of the PTFE sheet, but in order to fix this, this sheet was adjusted to a constant speed rolling roll temperature of 210 to 220 ° C. Passing pressurization was performed.

In this case, we decided to adjust this pressure so that the PTFE sheet would not deform. As a result, TiO ₂ is fixed and arranged on one surface of the PTFE sheet without interposing foreign matter in the PTFE sheet. However, TiO _{2 on} the surface of this sheet is arranged and fixed on the PTFE sheet without intervening foreign matter, but since it is excessively present on the surface, the sheet is ultrasonically dispersed in order to remove it. Oscillation in water was applied for 30 minutes with a container (Sharp DT-52).

Thus, the excess TiO ₂ was removed.

To explain the results, FIG. 1 is a 2000 × surface photograph taken by a scanning electron microscope (SEM), and FIG. 2 is a 10,000 × cross-sectional photograph taken by a transmission electron microscope (TEM).

1 and 2 are adopted to clarify the structure of the functional polymer sheet of the present invention.

From FIG. 1, it can be seen that TiO _{2 on the} surface of the functional polymer sheet is arranged and fixed on almost the entire surface.

Further, in FIG. 2, the right side is a cross section of PTFE and the left side is an epoxy-embedded resin. It is recognized that TiO ₂ is arranged and fixed on the surface of the PTFE sheet at that boundary without interposing foreign matter in the sheet.

Example 2 The same polymer sheet as in Example 1 was used,
The same surface treatment as in Example 1 was performed.

Moreover, tin oxide (SnO ₂ ) (T-1 made by Mitsubishi Metals) was used as the functional powder substance.

For dispersion, a dispersion having a concentration of 4% by weight was prepared in the same manner as in Example 1. Furthermore, the same method was used for coating. However, pressure was not applied by rolls in this preparation.

 The result is shown in FIG.

From the SEM 2000-times surface photograph shown in FIG. 3, it can be seen that SnO ₂ is arranged substantially uniformly over the entire sheet surface.

Next, from the cross-sectional photograph of TEM 10,000 times shown in Fig. 4, the right side is the cross section of PTFE, the left side is the epoxy-embedded resin, and SnO ₂
Has a primary particle size of about 0.02 μm and aggregates when the water in the dispersion is removed. Therefore, since they are fixed and arranged in this state, the conductivity of the tester can be measured in the plane direction. In this measurement, the sample width was 18 mm, the distance between the electrodes was 10 mm, and the results were measured with an analog tester sandwiched between gold-plated clips.
It was a meguohm.

Example 3 Polytetrafluoroethylene (cutting PTFE sheet having a thickness of 100 μm) was used as a polymer sheet, and the surface of this sheet was first subjected to a sputter hydrophilic treatment.

The sputtering process condition is 8 w · sec / cm ² .

Further, manganese dioxide (MnO ₂ , for chemicals) which is a catalyst was used as a functional powder substance, and this was adjusted to a concentration of 10% by weight with water.

The total amount of this adjustment liquid was 50 g, and a uniform dispersion liquid was obtained by using an ultrasonic oscillator (Sharp DT-52) for 30 minutes.

This dispersion was continuously applied to the sputtered surface of the polymer sheet by the bar coating method, and the temperature was adjusted to 10
The dispersion liquid was completely dried by evaporating water by passing it through a blast drying oven at about 0 ° C.

The sheet thus obtained has only MnO ₂ temporarily attached to the surface of the PTFE sheet, but in order to fix this, this sheet was adjusted to a constant-velocity rolling roll temperature of 210 to 220 ° C. Passing pressurization was performed.

In this case, we decided to adjust this pressure so that the PTFE sheet would not deform. As a result, MnO ₂ is fixed to one side of the PTFE sheet without interposing foreign matter on the sheet,
Arranged. However, MnO ₂ in this sheet
Although they are arranged and fixed on the PTFE sheet without any intervening foreign matter, the sheet is excessively present on its surface.
Underwater oscillation was applied for 30 minutes with DT-52).

Thus, excess MnO ₂ was removed.

To explain the results, FIG. 5 is a 2000 × surface photograph taken by a scanning electron microscope (SEM), and FIG. 6 is a cross-sectional photograph of a 10,000 × surface portion taken by a transmission electron microscope (TEM).

5 and 6 are functional polymer sheets of the present invention,
In this case, it is adopted in order to clarify the structure of the catalyst supporting sheet.

From FIG. 5, it can be seen that MnO _{2 on the} surface of the catalyst polymer sheet is arranged and fixed almost all over the surface.

Further, in FIG. 6, the lower side is the cross section of PTFE, and the upper side is the epoxy embedding acceptance. It is recognized that MnO ₂ is arranged and fixed on the surface of the PTFE sheet at that boundary without interposing foreign matter with the sheet.

An example of the demonstration experiment of this MnO ₂ sheet is shown.

The MnO ₂ is conventionally are representative as a catalyst for generating such as hydrogen peroxide (H ₂ O ₂₎ and reacted oxygen gas (O _2). In this reaction, since the MnO ₂ powder is allowed to directly act on the H ₂ O ₂ aqueous solution, once the reaction is performed, it is very difficult to stop the reaction on the way. However, this Mn
The use of the O ₂ -PTFE sheet is very advantageous because the reaction occurs only when the O ₂ -PTFE sheet is put into the H ₂ O ₂ aqueous solution, and the reaction stops when taken out.

As an experiment, this MnO ₂ PTFE sheet was cut into 30 mm × 50 mm, and another H ₂ O ₂ aqueous solution (manufactured by Mitsubishi Gas Chemical Co., Inc.) was diluted with water to obtain 0.2% by volume, 1.0% by volume, 5.0% by volume, Put each liquid adjusted to a concentration of 10.0% by volume into a 400 ml wide-mouth bottle,
The cut sheets were sequentially replaced from a low concentration, and the amount of O ₂ generated was measured by collecting in the liquid. In this case, the measurement temperature was 22 ° C.

 The results are shown in Table 1.

Example 4 As the polymer sheet, the same one as in Example 1 was used,
The same surface treatment as in Example 1 was performed.

In addition, titanium oxide / platinum (TiO ₂
Anatase type Pt2%) photocatalyst was used.

This creating method is exactly the same as that of the first embodiment. The resulting structural photographs are shown in FIG. 7 and FIG. 8 and the photographs corresponding to FIG. 6 are shown in FIG.

In FIG. 8, it can be seen that the surface portion of the PTFE sheet is arranged on the right side, the epoxy-embedded resin is arranged on the left side, and TiO ₂ .Pt is arranged on the mirror. As a result, as in Example 3, it was confirmed that TiO ₂ —Pt was aligned and fixed on the PTFE sheet surface of the polymer sheet without intervening foreign matter with the sheet.

It is well known that most of the photocatalyst TiO ₂ —Pt undergoes oxidation / reduction reactions and decomposes.
However, since this catalyst is fine particles, it is difficult to handle, and once it is used as a catalyst, it is difficult to collect it, and only a special filter can collect it. It is recognized that this is a catalyst-supporting polymer sheet that is solved by configuring it in this way. Table 2 shows the results of a simple photoreaction experiment for this TiO ₂ -Pt-supported PTFE sheet.

This Table 2 is a dispersion test of trichlene by ultraviolet rays in the presence of TiO ₂ —Pt-supporting PTFE sheet.

TiO ₂ -Pt-supporting PTFE sheet size 50 mm × 50 mm Put 100 ml of trichlene in a Petri dish and cover with quartz glass. The TiO ₂ —Pt-supporting PTFE sheet was immersed in this, and ultraviolet rays were irradiated at an irradiation distance of 500 mm using an ultraviolet lamp (H400P manufactured by Toshiba) 400W.

Note) The amount of acid in trichlene was measured by irradiating with ultraviolet light, taking out the TiO ₂ -Pt supporting sheet, putting it in a bottle, adding 200 ml of water, stirring and then neutralizing titration of the water.

As a result of this experiment, it is found that although trichlene is decomposed by ultraviolet rays, the decomposition is further promoted by the TiO ₂ —Pt-supporting PTFE sheet. This sheet is the result of repeated use of one sheet. It is a catalyst-supporting polymer sheet that is easy to handle with reproducible data because it is proportional to the irradiation time of ultraviolet rays and the decomposition amount of trichlene. Is recognized.

(G) Effect of the Invention As described above, in the functional polymer sheet according to the present invention,
The binder is not used on the surface of the polymer sheet, only the functional powder substance is arranged and fixed on the sheet surface without intervening foreign matter, and the density of the functional powder substance on the sheet surface is high. Therefore, it is possible to demonstrate high functionality with a completely new configuration that has never existed before.

Moreover, since the powder is fixed on the surface of the sheet, the powder does not fall off even under ultrasonic waves in the water, ensuring mechanical properties such as flexibility, flexibility, and strength, and dynamic motion involving mechanical vibration is ensured. This has the effect of obtaining a versatile product that can be used in various places.

In the functional polymer sheet of the present invention, the functional powder substance is a catalyst such as manganese dioxide or titanium oxide.
The one using a platinum-based catalyst has a wide range of industrial applications from the viewpoint of the catalytic function and economic efficiency of manganese dioxide, or the titanium oxide-platinum-based catalyst has an extremely high catalytic ability. Since the catalyst is originally very fine particles, it is extremely difficult to handle it. However, by having such a structure, the handleability becomes extremely high, and the use thereof is remarkably expanded.

[Brief description of drawings]

Fig. 1 is an enlarged photograph replacing the drawing showing the particle structure of the sheet surface where rutile TiO ₂ is arranged and fixed on the PTFE sheet surface, and Fig. 2 is an enlarged photograph replacing the drawing showing the particle structure inside. Yes, FIG. 3 is an enlarged photograph replacing a drawing showing the particle structure of the sheet surface on which SnO ₂ is arranged and fixed on the PTFE sheet surface, and FIG. 4 is an enlarged photograph replacing the drawing showing the particle structure inside thereof. Figure 5 shows the PTFE sheet surface
FIG. 6 is an enlarged photograph replacing a drawing showing a particle structure on the surface of a sheet on which MnO ₂ is arranged and fixed, FIG. 6 is an enlarged photograph replacing a drawing showing a particle structure inside the sheet, and FIG. 7 is PTFE.
FIG. 8 is an enlarged photograph replacing a drawing showing a particle structure of the sheet surface on which TiO ₂ —Pt is arranged and fixed on the sheet surface, and FIG. 8 is an enlarged photograph replacing a drawing showing a particle structure inside thereof.

Front page continuation (72) Inventor Hiroshi Miyatake 1-2 1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Electric Industry Co., Ltd. (72) Masao Abe 1-2 1-2 Shimohozumi, Ibaraki-shi, Osaka (72) Inventor Akira Ohtani 1-2-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Electric Industry Co., Ltd. (72) Inventor Takeshi Sasaki 1-2-1, Shimohozumi, Ibaraki-shi, Osaka No. Nitto Electric Industry Co., Ltd. (56) Reference JP-A-57-67667 (JP, A) Actually developed 52-142961 (JP, U)

Claims (2)

(57) [Claims] 1. A functional polymer sheet, wherein the functional powder substance is arranged and fixed on the surface of the polymer sheet without interposing foreign matter. 2. The functional polymer sheet according to claim 1, wherein the functional powder substance is manganese dioxide or titanium oxide-platinum catalyst which is a catalyst.