JPH11198275A - Anti-fogging sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anti-fogging sheet suitable for an operation protecting surface or the like hardly generating fog, excellent in transparency and hardly generating dust or the like. SOLUTION: Conductive layers 2, 3 containing conductive metal oxide are formed on both surfaces of a transparent support sheet 1 and a polymer layer 4 comprising a polymer having an ionic hydrophilic group is formed on the surface of at least one of the conductive layers 2, 3. The polymer layer 4 comprises a crosslinked material of a resin having a cationic quaternary ammonium base on its side chain and an overcoat layer 5 is desirably composed of a copolymer of methyl methacrylate and an acrylic acid ester and the conductive metal oxide is desirably composed of needle conductive metal oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifogging sheet, and more particularly, to a surgical protection surface for protecting a face during an operation and other suitable antifogging sheets for preventing fogging.

[0002]

2. Description of the Related Art In general, when performing surgery, doctors wear surgical protection surfaces to protect the face during surgery. There are two types of the protective surface for surgery: a regular use type and a disposable type.In the case of any of the surgical protective surfaces, it is desired that the light transmittance in the operating room is high without reflection by light in the operating room. However, if the protective face for surgery is clouded by moisture due to the breathing of the person wearing it,
It is desired that fogging does not occur because visibility is reduced and surgery becomes difficult. Furthermore, when dirt or the like adheres to the surgical protection surface, the visibility similarly decreases and the operation becomes difficult. Conventionally, various types of surgical protection surfaces have been proposed, but none of the above requirements can be satisfied.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an anti-fog sheet suitable for a surgical protective surface or the like which satisfies the above-mentioned demands. An object of the present invention is to provide an anti-fogging sheet that is difficult to perform and has a high light transmittance and does not reduce visibility.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to form a conductive layer containing a conductive metal oxide on one or both surfaces of a transparent support, and to form an ionic layer on at least one surface of the conductive layer. This is achieved by an antifogging sheet characterized in that a polymer layer comprising a polymer having a hydrophilic group is formed. The polymer desirably comprises a crosslinked product of an ion conductive resin having a cationic base in a side chain, particularly a resin having a cationic quaternary ammonium base in a side chain. Further, when the conductive layer is formed on both surfaces of the transparent support and the polymer layer is formed on one surface of the conductive layer, the refractive index of the polymer layer on the conductive layer surface opposite to the conductive layer. It is desirable to have an overcoat layer made of a resin having a refractive index of 0.06 or less. The conductive metal oxide contained in the conductive layer is particularly formed of a needle-shaped conductive metal oxide, and has a major axis of 0.2.
４4.0 μm, and the short axis is 0.01 to 0.04.
It is desirable to be in the range of μm. Further, a fluorine-based surfactant and / or a fluorine-based resin are added to the overcoat layer as needed.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a sectional view showing a preferred embodiment of an antifogging sheet of the present invention. In FIG. 1, 1 is a transparent support, 2, 3 are conductive layers, 4 is a polymer layer, and 5 is an overcoat layer. is there. Also, in FIG. 2, 1 to 4 are substantially the same as those shown in FIG. 1, and 6 is a polymer layer.

In the present invention, as the transparent support 1,
What is generally known as an insulating film is used. Examples of such materials include polyethylenes such as polyethylene terephthalate and polyethylene naphthalate,
Acrylics such as polyolefins such as polyethylene and polypropylene, polyamides, polyesteramides, polyethers, polyimides, polyamideimides, polystyrenes, polycarbonates, poly-p-phenylene sulfides, polyetheresters, polyvinyl chloride, and poly (meth) acrylates Resins and the like can be mentioned.
Among them, polyesters having high insulation properties and excellent in durability and dimensional stability are preferable, and polyethylene terephthalate is particularly preferable. The thickness of the transparent support is not particularly limited, but is 10 to 250 μm (particularly, 20 to 200 μm).
Is preferred because of easy handling.

[0007] The conductive layer 2 is a layer containing a conductive metal oxide and contains a conductive metal oxide and a polymer binder. Examples of the conductive metal oxide include aluminum-doped zinc oxide (0.12 to 0.25 μm), antimony-doped titanium oxide (0.2 μm), zinc oxide (1.0 μm), and antimony-doped tin oxide. Needle crystal (long axis: 0.2-4.0 μm, short axis: 0.01-
0.04 μm), particles coated with barium sulfate and tin oxide doped with antimony, K ₂ O.nTiO ₂ / S
nO ₂ Sb ₂ O ₃ (short axis 0.4 to 0.7 μm, long axis 10
To 20 μm).

As the conductive metal oxide, in particular, acicular tin oxide particles doped with antimony (long axis: 0.2 to 4.
0 μm, short axis: 0.01 to 0.04 μm).
Ordinary tin oxide particles doped with antimony darken the color of the conductive layer to be added and deteriorate the color. However, such defects are not present in the case of acicular tin oxide. In addition, in the case of spherical particles that are not acicular, in order to obtain predetermined conductivity, the amount of addition is larger than that of acicular particles, and blackening of the sheet is remarkable because antimony is distributed throughout the spherical particles. However, in the case of acicular tin oxide, the amount of doped antimony for obtaining a predetermined conductivity is smaller than that of the spherical particles because the doped antimony exists only on the surface of the acicular crystal.
Accordingly, as the conductive particles to be added to the conductive layer in the present invention, needle-like tin oxide particles doped with antimony are particularly preferable. In addition, when the antimony-doped acicular tin oxide particles are used, there is no humidity dependency that occurs when other conductive particles are used, that is, the conductivity is stable from low humidity to high humidity without being affected by humidity. Thus, a conductive layer having excellent transparency can be obtained.

The antimony-doped acicular tin oxide particles have a major axis of 0.2 to 4.0 μm and a minor axis of 0.01 to 0.1 μm.
It is preferably 0.4 μm, and more preferably the aspect ratio is 5 or more. Those having these ranges are particularly preferable because they can form transparency and uniform conductivity. The thickness of the conductive layer is selected depending on the intended conductivity and the like.
It is preferably from 0.03 to 1.0 μm, more preferably from 0.1 to 1.0 μm.
05 to 0.2 μm.

The polymer binder includes vinyl chloride, vinylidene chloride, vinyl acetate, styrene, methylstyrene, butadiene, acrylic acid, alkyl acrylate (alkyl group having 2 to 4 carbon atoms), PMM
A, a homoalkyl such as hydroxyalkyl acrylate, maleic anhydride or acrylonitrile, and a copolymer of at least two kinds selected from these monomers, polyester, gelatin, polyamide, etc. are used. Among them, gelatin, polyester, acrylic Resins are preferred.

The conductive layer 3 can be made of the same material as that of the conductive layer 2, but attention is particularly paid to haze, planarity, adhesive strength, conductivity and the like. The amount of the conductive substance added in the conductive layer 3 is:
50 to 90% by weight, preferably 7% by weight, based on the total solid content of the layer
It is from 0 to 90% by weight, particularly preferably from 75 to 85% by weight. When the content is less than 50% by weight, poor running tends to be caused by insufficient conductivity and adhesion of dust, and when the content is more than 90% by weight, defects in appearance such as coloring and haze tend to occur. The conductive layer 3 is made of an ion conductive polymer as a conductive substance,
A metal oxide or the like is used, and it is particularly preferable to use antimony-doped acicular tin oxide. The amount of the conductive substance added to the conductive layer 3 is 50 to 90% by weight, preferably 65 to 85% by weight, particularly preferably 70 to 90% by weight based on the total solid content of the layer.
~ 80% by weight. When the content is less than 50% by weight, poor running tends to be caused by insufficient conductivity and adhesion of dust, and when the content is more than 90% by weight, defects in appearance such as coloring and haze tend to occur.

The polymer layer 4 is made of a polymer having an ionic hydrophilic group. Such polymers include:
Examples thereof include polyamide, gelatin, polyvinyl alcohol, polyacrylic acid, polyamic acid, and other ionic conductive resins. Among these polymers, ionic conductive resins are particularly preferred. As the ionic conductive resin, a resin having an ionic hydrophilic group in a side chain is preferable, and as the ionic hydrophilic group, those having a cationic quaternary ammonium base or a sulfone group are particularly preferable in terms of cost. It is preferred in that respect. From the viewpoint of improving the transparency of the polymer layer 4 itself, an ionic conductive resin having an acrylic resin as a main chain and having a cationic quaternary ammonium base in a side chain is particularly preferable. Further, a crosslinked body of an ionic conductive resin having a cationic quaternary ammonium base is preferable from the viewpoint of the mechanical strength of the surface of the polymer layer 4 and the like.

The polymer layer 4 has a weight average particle diameter of 5 to 5.
30 nm of transparent inorganic particles can be contained.
When the inorganic particles are contained in the polymer layer 4, the state in which the inorganic particles are partially exposed on the surface of the polymer layer 4 is adjusted by adjusting the thickness of the polymer layer 4 and the particle diameter of the inorganic particles. Is desirable. Such a state is suitable for preventing the occurrence of scratches or the like on the surface of the polymer layer 4. If the particle diameter of the inorganic particles is smaller than 5 nm, the effect of preventing scratches or the like from being generated on the surface of the polymer layer 4 is small. Examples of the inorganic particles include clay, talc, diatomaceous earth, calcium sulfate, and aluminum hydroxide. In addition,
Components such as a slip agent and a film curing agent may be further added to the polymer layer 4 as needed.

The thickness of the polymer layer 4 is less than 0.1 μm,
Alternatively, a thickness exceeding 1.1 μm is desirable. This is because when the thickness of the polymer layer 4 is in the range of 0.1 to 1.1 μm, rainbow unevenness or the like is likely to occur due to the influence of light interference or the like.

The overcoat layer 5 is desirably a layer made of a resin having a refractive index difference of 0.06 or less from the refractive index of the polymer layer 4, and a resin having a smaller refractive index difference is more preferable. It is not preferable to use a resin having a refractive index whose difference from the refractive index of the polymer layer 4 exceeds 0.06 for the overcoat layer 5 because the transparency of the antifogging sheet decreases.
Therefore, the resin used for the overcoat layer 5 is
It should be selected according to the relative relationship with the polymer used for the polymer layer 4.

As a resin used for such an overcoat layer 5, for example, an acrylic resin is preferable.
That is, among the resins that can be used for the polymer layer 4, the most preferred resin is an ionic conductive resin having an acrylic resin as a main chain and a cationic quaternary ammonium base in a side chain. The acrylic resin is most preferred as the resin used in the above. Among acrylic resins, copolymers of methyl methacrylate and acrylic acid ester are particularly suitable for production as well as transparency (general solvents, ME
K, toluene, etc.).

When a copolymer of methyl methacrylate and acrylate is used for the overcoat layer 5 and a fluorine surfactant and / or a fluorine-based transparent polymer is added, the overcoat layer 5 Adhesion of dust on the surface can be prevented, and generation of scratches and the like on the surface can be prevented. Here, as the fluorine-based surfactant, for example, Megafac F-17
8K (a perfluoroalkyl group-containing oligomer manufactured by Dainippon Ink and Chemicals, Inc.). Examples of the fluorine-based transparent polymer include Aron GF-300 (a comb-type graft polymer manufactured by Toa Gosei Chemical). Is mentioned. The addition amount of the fluorine surfactant and / or the fluorine-based transparent polymer is used in a range that does not impair the transparency of the overcoat layer 5.

Further, the overcoat layer 5 can contain polymer particles having a refractive index of 0.06 or less from the refractive index of the polymer constituting the overcoat layer 5. In particular, the polymer particles are preferably crosslinked polymer particles. When such polymer particles are contained in the overcoat layer 5, the overcoat layer 5
The antireflection effect of the surface is exhibited, the light transmittance is improved, and the transparency of the antifogging sheet is increased. As these polymer particles, for example, polyethylene, polyolefin such as polypropylene, polymethyl methacrylate, styrene resin, melamine resin, epoxy resin and the like are used, but organic polymer compounds, preferably thermoplastic resins, among them, especially polyolefin filler Is preferably used. The polyolefin particles not only improve the slipperiness of the layer, but also increase the heating temperature (1
(00 to 120 ° C.), the spherical particles are slightly flattened due to softening, and the slipperiness and running properties are further improved. The polymer particles are added in an amount of 1 to 10% by weight, preferably 1 to 5% by weight, particularly preferably 1 to 3% by weight, based on the total solid content of the overcoat layer 5. If it is less than 1% by weight, the slipperiness tends to decrease, and if it is more than 10% by weight, haze tends to occur.

FIG. 2 is a sectional view showing another preferred embodiment of the antifogging sheet of the present invention. 2 differs from the antifogging sheet shown in FIG. 1 in that a polymer layer 6 substantially the same as the polymer layer in FIG. 1 is provided instead of the overcoat layer 5 in FIG. Since the antifogging sheet is provided with the polymer layer 4 and the polymer layer 6 on both sides, fogging on both sides of the antifogging sheet can be prevented, and the transparency of the antifogging sheet becomes higher. .

In the present invention, for the sake of convenience, an anti-fog sheet is expressed, but depending on the thickness, an anti-fog film is substantially included in the present invention. When the antifogging sheet of the present invention is used as a surgical protection surface, the antifogging sheet is used such that the surface having the polymer layer is located on the human face side.

[0021]

The present invention will be described in more detail with reference to the following examples. <Formation of conductive layer 2> A solution having the following composition was applied,
For 1 minute. The coating weight after drying was 1 g / m ² . Gelatin (761 gelatin manufactured by Nitta Co.) 2 parts by weight Antimony-doped acicular tin oxide (FS-10D; manufactured by Ishihara Sangyo) 600 parts by weight Alkyl benzene ether polyoxyethylene (EMALEX W160; manufactured by Nippon Emulsion Co.) 1 part by weight Water 397 Parts by weight

<Formation of Conductive Layer 3> A conductive layer solution having the following formulation was applied and dried at 160 ° C. for 1 minute. The coating weight after drying was 0.3 g / m ² . Conductive layer solution: Polyacrylate (Julima ET410; manufactured by Nippon Pure Chemical Co., Ltd.) 19 parts by weight Sodium dodecyl sulfate (Sanded BL; manufactured by Sanyo Chemical Co., Ltd.) 1 part by weight Antimony-doped acicular tin oxide (FS-10D; Ishihara Sangyo Co., Ltd.) 175 parts by weight Alkyl benzene ether polyoxyethylene (EMALEX W160; manufactured by Nippon Emulsion Co., Ltd.) 1 part by weight Trimethylol melamine (SUMITEX RESIN M-3; manufactured by Sumitomo Chemical Co., Ltd.) 4 parts by weight Water 800 parts by weight

<Formation of Polymer Layer 4> A hydrophilic polymer having the following composition was applied and dried at 120 ° C. for 1 minute. The coating weight after drying was 1.5 g / m ² . Polymer layer liquid; Methanol 750 parts by weight Resin having cationic quaternary ammonium base 250 parts by weight

<Formation of Overcoat Layer 5> A liquid having the following formulation is applied as an overcoat layer. Toluene 240.3 parts by weight MEK 219.6 parts by weight Cyclohexanone 342.7 parts by weight Copolymer of MMA and acrylate, 20% toluene solution (Dianal BR80: manufactured by Mitsubishi Rayon Co., Ltd.) 192.2 parts by weight Megafax F-178K (Perfluoroalkyl group-containing oligomer, manufactured by Dainippon Ink and Chemicals, Inc.) 2.5 parts by weight After application, the coating is dried at 120 ° C. for 1 minute. Coating weight is 0.8
g / m ² .

The obtained antifogging sheet was measured for scratching strength, light transmittance, antifogging property and dust suction property. Evaluation method Scratch strength: A load of 0 to 100 g is continuously applied to a length of 100 m / m, and the difficulty of scratching can be evaluated at the distance at the beginning of scratching. The needle used has a radius of curvature of 0.2Φ
It is. The scratch strength is preferably 20 g or more. Light transmittance: Suga haze was measured by a computer. If the light transmittance is 89% or more, there is no practical problem. Anti-fogging property: In a room at 10 ° C., breath is blown, and the degree of fogging of the blown surface is evaluated. ○ No fogging, △ Very slight fogging, × Fogging Dust suction: The adhesion state of dust on the antifogging sheet was visually judged. ○ Almost no dust attached, △ Very little dust attached, × Many dust attached

Example 1 A conductive layer liquid 2 was applied to a 100 μm PET base, and after drying, a polymer layer liquid 4 was applied thereon. In each of the following Examples and Comparative Examples, the conductive layer liquid 3 was applied to the BC surface, and then the overcoat layer liquid 5 was applied. <Comparative Example 1> Polymer layer liquid 4 on 100 µm PET base
Was applied. <Example 2> Cationic colloidal silica was added to the polymer layer solution 4 of Example 1. Comparative Example 2 A conductive layer liquid 2 was applied to a 100 μm PET base. <Comparative Example 3> An overcoat layer liquid was applied on the conductive layer 2 liquid of Comparative Example 2.

Table 1 summarizes the evaluation results.

[Table 1]

[0028]

As described above, according to the present invention, a conductive layer containing a conductive metal oxide is formed on one or both surfaces of a transparent support, and an ion-conductive layer is formed on at least one surface of the conductive layer. Since a polymer layer made of a polymer having a hydrophilic group is formed, it is possible to prevent the occurrence of fogging on the surface of the antifogging sheet, and at the same time, to prevent adhesion of dust and the like, and to provide a surgical protection surface, etc. It is suitable for.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a preferred embodiment of an antifogging sheet of the present invention.

FIG. 2 is a sectional view showing another preferred embodiment of the antifogging sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent support 2 Conductive layer 3 Conductive layer 4 Polymer layer 5 Overcoat layer 6 Polymer layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B32B 27/18 B32B 27/18 J 27/30 27/30 A

Claims (10)

[Claims] 1. A conductive layer containing a conductive metal oxide is formed on one or both surfaces of a transparent support, and at least one surface of the conductive layer is made of a polymer having an ionic hydrophilic group. An anti-fogging sheet having a polymer layer formed thereon. 2. The antifogging sheet according to claim 1, wherein the polymer is made of an ion conductive resin having a cationic base in a side chain. 3. The antifogging sheet according to claim 2, wherein the ionic conductive resin comprises a crosslinked product of a resin having a cationic quaternary ammonium base in a side chain. 4. The conductive layer is formed on both sides of a transparent support, the polymer layer is formed on one side of the conductive layer, and the polymer layer is bent on the conductive layer surface opposite to the conductive layer. The antifogging sheet according to any one of claims 1 to 3, further comprising an overcoat layer made of a resin having a refractive index of 0.06 or less. 5. The antifogging sheet according to claim 4, wherein the overcoat layer is made of an acrylic resin. 6. The antifogging sheet according to claim 5, wherein the acrylic resin is made of a copolymer of methyl methacrylate and an acrylic acid ester. 7. The polymer layer according to claim 1, wherein the particle diameter is 5 to 30 n.
The antifogging sheet according to any one of claims 1 to 6, further comprising m transparent inorganic particles. 8. The antifogging sheet according to claim 4, wherein the overcoat layer contains a fluorine-based surfactant and / or a fluorine-based resin. 9. The conductive metal oxide comprises a needle-shaped conductive metal oxide, the major axis of which is in the range of 0.2 to 4.0 μm, and the minor axis of which is 0.01 to 0.04 μm. The antifogging sheet according to any one of claims 1 to 8, wherein 10. The overcoat layer contains a copolymer of methyl methacrylate and an acrylate, and contains polymer particles having a refractive index difference of 0.06 or less from the refractive index of the copolymer. The antifogging sheet according to claim 6, wherein