JPH04365085A - Hologram - Google Patents

Abstract

PURPOSE:To provide a hologram having no aging color change, no out-of-focus of an image, and excellent durability in use for a long period by forming a noncrystalline fluorine-containing polymer layer on the surface. CONSTITUTION:When gelatin dichromate (DCG) is used as a photosensitive material for wet development processing, the DCG is applied on a glass dry plate 1, and the DCG is exposed with the preset laser beam and an optical system. It is processed with a preset developer to form a transmission type or reflection type recorded sheet-like hologram 2, then a layer of noncrystalline fluorine-containing polymer 3 is formed on one face of both faces of the hologram 2. The noncrystalline fluorine-containing polymer layer can be formed by the coating method or the film laminating method. An unexposed photosensitive material for hologram recording may be formed on the sheet or film of the noncrystalline fluorine-containing polymer 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to holograms.

0002

2. Description of the Related Art Conventionally, when producing a hologram by wet development processing, silver salt, dichromate gelatin (hereinafter referred to as DCG), and the like are known as photosensitive materials. At this time, the photosensitive material is coated on a transparent glass dry plate, and after exposure, it is immersed in a developer and dried in the air to produce a hologram. Therefore, if a hologram formed on a glass dry plate is left in the air as it is, the hologram may deteriorate due to changes in humidity or the surface may be damaged.

[0003] Therefore, a plate glass is attached to the hologram surface exposed to the air, but this requires time and effort, and the glass becomes thicker and heavier, making it inconvenient to handle. In addition, photopolymerizable photopolymers (DuPont OM
NI-DEXR) etc. are known, but in this case, the photopolymer is polyethylene terephthalate (hereinafter referred to as PE
It is covered with a transparent plastic film such as T. The development method is to use ultraviolet light (wavelength 300) after exposure.
This is done by irradiating the PET film (nm to 400 nm) or applying heat to about 100°C, but irradiation with ultraviolet rays causes the PET film to deteriorate and turn yellow, and further heat can cause the PET film to deform. had. In addition, photopolymers are affected by moisture,
There was also the problem that the image could become blurry.

0004

[Problems to be Solved by the Invention] The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a new hologram that was previously unknown. It is something to do.

[0005]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a sheet-like hologram recorded by a transmission type or a reflection type. Provided is a hologram characterized by forming a layer of a crystalline fluorine-containing polymer, and a hologram characterized in that an unexposed photosensitive material for hologram recording is formed in the form of a sheet or film of an amorphous fluorine-containing polymer. do.

[0006]

[Example] The present invention will be explained below according to an example. FIG. 1 shows a sectional view of the basic configuration of the present invention. When DCG is used as a photosensitive material by wet development, first, the DCG is applied onto a glass dry plate 1 and exposed to light using a predetermined laser beam and an optical system. Next, after processing with a predetermined developer to form a hologram 2, a layer of amorphous fluorine-containing polymer 3 is formed on the surface of the hologram 2. Here, the amorphous fluoropolymer layer can be formed by a conventional method such as coating or film lamination. In particular, the coating method
This is suitable because a thin film can be easily formed.

[0007] As the coating method, coating using a doctor blade or bar coater is preferable, and spray coating, brush coating, spin coating and dip coating are also possible. In addition, coating can be carried out using a suitable solvent (for example, perfluoro(2-butyltetrahydrofuran),
A perfluorinated solvent such as perfluorotributylamine is preferable) and coated by the above method, followed by drying at a temperature of about 100 to 150° C. for about 1 hour.

The thickness of the amorphous fluoropolymer layer is preferably about 1 μm to 10 μm. If this layer is too thin, a sufficient protective effect may not be obtained, which is undesirable. Moreover, if it is too thick, it is economically unfavorable.

[0009] As fluorine-containing polymers, polytetrafluoroethylene resin, perfluoroethylene propylene resin, perfluoroalkoxy resin, polyvinylidene fluoride resin, ethylene-tetrafluoroethylene resin, polychlorotrifluoroethylene resin, etc. are widely known. However, many of these fluoropolymers have crystallinity, which causes light scattering and poor transparency.

Amorphous fluorine-containing polymers have excellent transparency because they do not scatter light due to crystals. Examples of non-crystalline fluorine-containing polymers include fluoroolefins such as terpolymers containing 37 to 48% by weight, 15 to 32% by weight, and 26 to 44% by weight of tetrafluoroethylene, vinylidene fluoride, and hexafluoropropylene, respectively. These include copolymers of the same type, and polymers having a fluorine-containing aliphatic ring structure. In particular, polymers having a fluorine-containing aliphatic ring structure are preferably employed because they have excellent mechanical properties such as creep resistance.

[0011] Polymers having a fluorine-containing aliphatic ring structure include those obtained by polymerizing monomers having a fluorine-containing ring structure, and those obtained by cyclopolymerizing a fluorine-containing monomer having at least two polymerizable double bonds. A polymer having a ring structure in the main chain is suitable.

[0012] A polymer having a ring structure in the main chain obtained by polymerizing a monomer having a fluorine-containing ring structure was disclosed in Japanese Patent Publication No. 6
It is known from No. 3-18964 and the like. That is, by homopolymerizing a monomer having a fluorine-containing ring structure such as perfluoro(2,2-dimethyl-1,3-dioxole),
It is obtained by copolymerizing with a radically polymerizable monomer such as tetrafluoroethylene.

Further, a polymer having a ring structure in the main chain obtained by cyclopolymerizing a fluorine-containing monomer having at least two polymerizable double bonds is disclosed in JP-A No. 63-238111.
No. 63-238115, etc. That is, it can be obtained by cyclization polymerization of monomers such as perfluoro(allyl vinyl ether) and perfluoro(butenyl vinyl ether), or by copolymerization with a radically polymerizable monomer such as tetrafluoroethylene.

[0014] Also, perfluoro(2,2-dimethyl-
A monomer having a fluorine-containing ring structure such as 1,3-dioxole) and at least 2 monomers such as perfluoro(allyl vinyl ether) and perfluoro(butenyl vinyl ether).
A polymer obtained by copolymerizing a fluorine-containing monomer having two polymerizable double bonds may also be used.

The polymer having a fluorine-containing aliphatic ring structure is preferably a polymer having a ring structure in the main chain, and one containing 20% or more of the ring structure is preferable from the viewpoint of transparency, mechanical properties, etc.

[0016] The most preferable non-crystalline fluoropolymer is one with a crystallinity of 0%, but even a small amount of crystallinity can be used as long as it does not impair transparency. It is. In the present invention, the amorphous fluoropolymer used has a crystallinity of 10% or less.

[0017] In addition, photopolymers (OMNI-DEXR, Dupont Co., Ltd.,
When a PET film (10 to 25 μm thick) is used, a PET film is already formed on both sides of the photopolymer, so exposure is performed in that state. Therefore, after exposure, one side of the PET film was peeled off and the photopolymer side was pasted on the glass dry plate 1 in Figure 1, and then the other side of the PET film was peeled off.
Also peel off the T-film. Therefore, a non-crystalline fluorine-containing polymer is coated as in the case of the DCG material described above. Here, an amorphous fluorine-containing polymer film or sheet may be used instead of the glass dry plate shown in FIG.

The hologram of the present invention produced in the manner described above did not exhibit image blurring even after being left at a constant temperature and humidity of 80° C. and 90% for 1000 hours. Also, for comparison,
When similar tests were conducted on a film that did not form an amorphous fluoropolymer layer and a polyvinyl alcohol film instead of the amorphous fluoropolymer, the images became blurred in about one day in both cases.

[0019]

Effects of the Invention The amorphous fluorine-containing polymer used in the present invention has an extremely high light transmittance and almost no absorption of ultraviolet rays, so there is no color deterioration over time, and the water absorption rate is 0. 01% or less, and has excellent chemical resistance. In addition, PET film has polarizing properties, which has an adverse effect on recording and reproducing holograms, but amorphous fluorine-containing polymers can be coated with a thin film of several micrometers, and do not have polarizing properties, so there is no adverse effect.

[Brief explanation of the drawing]

FIG. 1: Cross-sectional view of the basic configuration of the present invention

[Explanation of symbols]

1 Glass dry plate 2 Hologram 3 Amorphous fluoropolymer

Claims (3)

[Claims] 1. A sheet-like hologram recorded by a transmission type or reflection type, characterized in that the hologram has a layer of an amorphous fluorine-containing polymer on one or both sides. 2. A hologram, wherein an unexposed photosensitive material for hologram recording is formed on a sheet or film of an amorphous fluorine-containing polymer. 3. The hologram according to claim 1, wherein the amorphous fluorine-containing polymer is a polymer having a fluorine-containing aliphatic ring structure.