JPS6132670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing artificial stone ornaments containing photographs, the main purpose of which is to prevent discoloration or fading of photographs.

Recently, stone materials such as gate signs, nameplates, stone monuments, grave markers, pedestals of sculptures, and ceramics such as Western plates, etc.
Pasting photos that serve as various memories is becoming popular. Normally, when a photo is pasted, it naturally becomes higher than the base material surface by the thickness of the photo and the thickness of the adhesive layer.
The photo part will stick out. In order to avoid such protrusion, it would be sufficient to make a depression in the base material and fill this part, but creating this depression requires a considerable amount of effort. Also,
In order to protect photographs pasted by these methods, a resin layer is provided on the photographs to improve mechanical strength and provide weather resistance. However, in order to prevent discoloration or fading of photographs, especially color photographs, both the front and back sides of photographic paper are usually coated with a resin treatment to prevent moisture, which may result in insufficient drying after development. For example, even if the paper has been sufficiently dried, when the surrounding area is cut, the papery part of the photographic paper will be exposed on the cut surface, and new moisture will be absorbed from this part, so the papery part will contain more or less moisture. This moisture can cause discoloration or fading of photographic images, so if ordinary photographic paper is pasted as is, no matter how much you protect it with a resin film, etc., the original color will remain for a long time. It is extremely difficult to preserve it for a long period of time.

This invention was made to eliminate these drawbacks of conventional methods, and involves forming a resin film layer on a mirror-finished smooth plate, and leaving this resin film layer in a semi-cured state. At some point, the moisture-proofing resin film was peeled off to expose the papery part, and a dried photographic paper was placed over the semi-cured resin film layer with the photographic image side (surface) facing down.
A resin film layer is further provided on top of the resin film layer, and photographic paper is inserted between the resin film layers in a sandwich pattern while vacuum degassing is performed.After the resin film layer is semi-cured or hardened, this resin film layer is smoothed. While still on the plate, place it in a formwork with the desired shape, pour resin liquid containing stone powder onto it under reduced pressure, then place a press plate and apply pressure to harden the resin liquid. This invention provides a method for producing a photo-engraved artificial stone ornament, which is characterized by removing the smooth plate, press plate, formwork, etc. after curing.The details of this invention will be described below.

First, in this invention, the mirror-finished smooth plate is used to avoid the trouble of polishing the surface of the final product, and includes glass plates, iron plates, aluminum plates, other chrome-plated steel plates, etc. It is a rigid material that has been surface-treated to have a mirror-like surface. Such a smooth plate is coated with a conventional mold release agent such as metal salts of higher fatty acids, silicone resin, polyvinyl alcohol, paraffin, waxes, etc., or a release paper, a synthetic resin film for mold release, etc. is laid down, A resin film layer is formed thereon. The resin at this time is particularly excellent in transparency and weather (light) resistance, and is preferably of the same type as the binder for artificial stone described below, if possible. Here, thermoplastic resins and thermosetting resins that require high temperatures during molding are not suitable for artificial stones, let alone photographic images, and furthermore, they are not suitable for use with artificial stones, and furthermore, they do not contain organic solvents. It is also undesirable to use it. Therefore, reactive mixed resins such as polyester resins, epoxy resins, urethane prepolymers, polysulfide resins, silicone resins, acrylic resins, etc. are suitable, but polyester resins are usually used for artificial stone. Therefore, it is advantageous to use polyester resin in this invention as well.

A curing agent, a curing accelerator, an ultraviolet absorber, etc. are added to this reactive mixed resin as appropriate, and the resin liquid, which has a slightly lower viscosity than starch syrup, is mixed with a mold release agent (material) and placed horizontally. Coating, spraying or pouring onto a board to form a film. The film thickness at this time does not need to be particularly limited, but may be approximately 0.2 to 2.0 mm. When this resin film layer is in a semi-hardened state, photographic paper is placed over the resin film layer with the photographic image side (surface) facing down while being lightly pressed with a roller or the like.

Photographic paper, especially for color photography, usually has a photosensitive agent film on one side and a paper base on both sides.
Since resin processing is performed primarily for the purpose of moisture proofing, in the present invention, the resin processed surface of the back side (opposite side of the photosensitive agent film) of such photographic paper is peeled off to expose the paper base material. This is because the photographic paper is not sufficiently dried after printing and developing, or even if it is sufficiently dried, moisture is gradually absorbed from the cut surface around the photographic paper. A considerable amount of moisture is often occluded within the paper base material, and this occluded moisture can cause discoloration or fading of images, foaming during resin encapsulation, and even peeling. Peel off the resin-treated back surface to expose the paper base material. This is to facilitate the removal of moisture contained in the paper base material, and after thoroughly drying the exposed paper base material using a drying drum or an infrared lamp, the semi-cured resin film is removed. This is applied over the layers.

In this way, when the photo has been covered on the semi-cured resin film layer, a liquid resin of the same quality as the previous resin is applied, sprayed or injected over it to form a new resin film layer (the thickness is the same as the resin film layer). However, it is important to improve the adhesion between the semi-cured resin film layer, the photo and the new liquid resin film layer, and to use air or gases generated during the curing process. Curing under vacuum is preferred for degassing. In this way, the transparent resin penetrates between the fibers of the paper base material of the photographic paper, and the paper base material becomes transparent.
The time required for curing can be adjusted appropriately by the temperature as well as the type and amount of the curing agent and curing accelerator, but in order to prevent deterioration of the photographic image, deformation of the resin film layer, etc. Exposure to higher temperatures than necessary should be avoided, and should normally be kept at room temperature or
It is best to choose a temperature around 60℃.

Next, a photograph is sealed between the layers in a suitable place in a casting frame of a desired shape (for example, a picture frame) prepared in advance, and the semi-cured or hardened resin film layer is placed on a smooth plate. A resin liquid containing stone powder particles is injected from above under reduced pressure, and a press plate is placed on top of the resin liquid to harden the resin liquid while applying pressure. As the resin liquid containing stone powder particles contracts when it hardens, the smooth plate (especially in the case of a glass plate) and the resin film layer thereon may be bent, cracked, etc., and destroyed. It is desirable to frame the peripheral edge of the resin film layer with a frame made of a material having rubber elasticity (for example, silicone rubber, etc.). By varying the shape of this edging frame, it is possible to give the cast molded product a certain level of unevenness, and together with the shape of the cast frame provided on the outer shell, it is possible to enhance the decorative effect. In addition, if all of these frames are provided with a mold release agent (material),
Mold release becomes easy. Further, the material of the casting frame is not particularly limited, but from the viewpoint of hardness, weight, strength, or workability, a pressed product of a metal plate or one made of hard rubber is convenient for use.

The stone powder used in this invention is the main raw material for artificial stone, and includes surrogate stone, granite, agate,
Not only powders of other natural stones, but also metal compounds such as calcium carbonate, calcium oxide, titania, alumina, and magnesia, powders of secondary products associated with waste treatment such as slag or calcined sludge, and even bricks. It also includes crushed powder of ceramic products such as ceramics, etc., and may be a single substance or a mixture of two or more of these. The liquid resin to be mixed as a binder for such stone powder particles is preferably one equivalent to the resin used in the resin film layer that encapsulates the photograph, such as polyester resin, epoxy resin, urethane prepolymer,
It is a reactive mixed resin such as polysulfide resin, silicone resin, and acrylic resin. After appropriately adding a curing agent, curing accelerator, etc. to these resins, 1 part by weight of the liquid resin is mixed with 2 to 5 parts by weight of the stone powder. Here, if the amount of liquid resin is increased, the fluidity of the mixture will increase and casting will be easier, but the color, gloss, texture, etc. of artificial stone will be inferior.
On the other hand, if there are too many stone powder particles, the liquid resin will not be effective as a binder, and the fluidity will deteriorate, making it difficult to perform casting smoothly.

As described above, the mixture of stone powder particles and liquid resin liquid is injected under reduced pressure into a casting frame in which a smooth plate whose periphery is edged with a rubber elastic material and a resin film layer with a photograph enclosed therein are arranged. For example, a molding frame is placed in a container that can be depressurized so that the internal situation can be properly observed, and valve plugs are used to pour liquid resin mixed with stone powder onto the container. A funnel-shaped inlet or reservoir is provided, and its legs penetrate the container wall and are fixed in a position such that the resin liquid poured from the lower end of the legs falls approximately in the center of the casting frame. I'll keep it. If such a device is used, the resin liquid can be easily sucked into the container by opening and closing the valve plugs as appropriate depending on the degree of pressure reduction in the container, and moreover, the resin liquid can be easily sucked into the resin liquid even while falling. This makes it possible to remove the air that is present in the mold, further increasing the effectiveness of vacuum casting and eliminating the possibility of any air bubbles remaining in the molded product. In addition, if stone powder particles or pigments of different colors are mixed into the resin liquid and dropped into the casting frame, beautiful streaked or spotted patterns can be created on the molded product due to the flow of the resin liquid. I can do it. This kind of pattern depends on the type of coloring material,
Although it is possible to make various changes depending on the amount, mixing method (imperfection of mixing), etc., even if it is possible to reproduce a similar pattern, it is an attempt to obtain two or more molded products with exactly the same pattern. It is extremely difficult. However, this is proof that many random elements remain, and a molded product with extremely natural beauty can be obtained.

When the resin liquid is cast, a press plate coated with a mold release agent (material) is placed on top of the resin liquid layer, and at this time, a square piece made of the same material is appropriately placed in the resin liquid layer, or By applying pressure using a press, a parallel relationship between the casting frame and the press plate is obtained, and the resin liquid layer is gradually cured while preventing shrinkage and deformation that occurs during the curing process. It is desirable that the curing speed at this time be slightly slower than that of the resin film layer that encapsulates the photograph. This is because if the amount of resin is too large and the curing speed is too fast, heat generation will be intense, distortion will easily occur, and it will be difficult to obtain a homogeneous artificial stone substrate. Therefore, the curing speed is usually adjusted by appropriately selecting the type, amount, or curing temperature of the curing agent and curing accelerator. A method is adopted in which the material is heated to a temperature above (for example, around 50°C) for an appropriate period of time (for example, about 30 minutes to 1 hour) to cause an initial curing reaction, and then left at room temperature to complete the remaining curing reaction. It goes without saying that the latter method is advantageous, especially when mass production is desired.

After the curing reaction is completed, the press plate, smooth plate, various frames, etc. are all removed to obtain the desired artificial stone ornament with a photo. Note that although thin burrs may be formed by the injected resin on the peripheral edges of the smooth plate and the resin film layer, there is no particular need for surface finishing other than the finishing of these burrs (these can be easily removed). Moreover, according to the method of this invention, the photographic paper part of the enclosed photograph will not be higher than the surrounding surface, and furthermore, the resin constituting the resin film layer will not be present between the fibers of the papery part of the photographic paper. Penetrate,
The paper part will no longer absorb moisture again.
Therefore, the discoloration or fading of the various pigments contained in photographic images is not accelerated by humidity at all, and clear and beautiful images can be preserved for an extremely long period of time compared to conventional methods. It becomes possible.

Examples will be described below.

Example Glass plate with mirror finish (22.5cm x 17.8cm)
On top of this, a polyester film is temporarily glued with water glue as a release material, and on top of this, 0.08% of a hardening agent (Permec, manufactured by Takeda Pharmaceutical Company Limited) and 0.04% of a curing accelerator (cobalt naphthenate) are placed.
An unsaturated polyester resin (having a viscosity similar to that of starch syrup) was sprayed to form a thin layer approximately 0.3 mm thick. After about 20 minutes at room temperature of 20°C, the resin layer became semi-cured.

On the other hand, peel off the moisture-proof resin layer on the back of color photographic paper (20cm x 15cm), expose the paper base material of the photographic paper, and dry it at about 40℃ for 30 minutes while irradiating it with an infrared lamp. did.

This dried color photograph with the back side peeled off was placed on the semi-cured unsaturated polyester resin layer with the image side facing down, and the image surface was pressed while pressing lightly with a roller. Spray the same unsaturated polyester resin liquid to approximately 0.3 mm.
A thick resin layer is formed, sandwiched between two stainless steel plates, and the pressure is reduced between them to defoam and harden the resin layer.A resin film with a thickness of approximately 0.6 mm is created by enclosing a color photograph in the shape of a sandwich. (22.5 cm x 17.8 cm) layers were obtained.

With this resin film layer placed on the glass plate, place it in the center of a picture frame casting frame (outer dimension: 32 cm x 27 cm, inner dimension: 28 cm x 23 cm) whose inner surface is made of stainless steel plate and which has been coated with a mold release agent. The resin film layer and the glass plate were surrounded by a silicone rubber frame (with the curved surface facing upward) having a semicircular cross section (radius of about 10 cm). If you make a small hole with a diameter of about 1 mm in the center of the stainless steel picture frame casting frame, by blowing air into this hole after casting, the molded product can be molded together with the glass plate. It is convenient because it can be easily released from the mold.

As described above, once the glass plate and the resin film layer for enclosing the photograph had been installed in the picture frame casting frame, it was placed in a container capable of reducing the pressure. Here, the reduced pressure container is provided with a funnel-shaped reservoir of resin liquid (including artificial stone powder particles) with a cone, and the resin liquid flowing down from the legs is placed approximately in the center of the casting frame installed in the container. It is fixed so that it will not fall.

Next, an unsaturated polyester resin containing 0.05% of a hardening agent (the above-mentioned Permec) and 0.03% of cobalt naphthenate as a hardening accelerator is added to a powder mixture of 3.5 parts by weight of surrogate stone powder and 1.0 parts by weight of calcium carbonate powder. 1.0 part by weight of starch syrup was added and mixed, and the mixture was poured into the resin liquid reservoir in the funnel.
At this time, in order to add a brown striped pattern to the molded product, add a small amount of brown pigment, stir lightly, and while suctioning the inside of the vacuum container, gradually open the pot and pour the resin liquid onto the casting frame. Made it fall. When the desired amount of resin has completely fallen and the suction is continued for about 10 minutes, the deaeration is almost complete, so the pressure inside the container is returned to normal pressure, the molding frame is taken out from the container, and the stainless steel is poured onto the resin liquid layer. A press plate coated with a mold release agent manufactured by Manufacturer Co., Ltd. was placed on the plate, and the plate was placed in a thermostat and heated at 50°C for 1 hour, and then left at room temperature for about 10 hours. After this process, the resin has almost completely cured, so
The molded product was removed from the casting frame, and the press plate, glass plate, and silicone rubber frame were sequentially removed to obtain an artificial stone frame with a photo in the desired shape. The brown pigment added to the casting resin solution appeared in stripes on the artificial stone, creating an extremely beautiful pattern that was indistinguishable from natural stone.

Furthermore, in order to investigate the weather resistance of the artificial stone plaque with a photo made using the method shown in this example, we investigated conventional products,
That is, on the surface of an artificial stone plate (same as the above prescription),
A color photograph was pasted on the back of the photographic paper without peeling off the resin-treated layer, and a resin (unsaturated polyester resin liquid with the above composition) was applied and cured on top of it, and the photograph surface was placed on a tin roof. An exposure test was conducted with the product facing upwards from December 1974 to the present (October 1980) (approximately 11 months), and the conventional product showed slight discoloration and fading after approximately one month. However, although some defects have started to appear and some of the primary colors are now visible (peeling off) and the primary colors in color photographs are almost invisible, the results obtained in the examples based on the method of this invention are as follows: Even now, it still maintains vivid images and colors, with no signs of peeling, discoloration, or fading.

Therefore, according to the method of the present invention, there is no step at all on the periphery of the photo-encasing part, and the photo-enclosure surface is a perfect mirror surface, so surface finishing after casting is not particularly necessary. By performing molding under reduced pressure, air bubbles and moisture that are occluded or mixed in photographic paper, artificial stone powder, liquid resin, etc. are removed, so there is no peeling, discoloration, or fading, and the product can last for a long time. It became clear that it could withstand storage. Therefore, it can be said that the method of the present invention is extremely effective not only for indoor decorations but also for various decorative items used outdoors such as gate signs, nameplates, stone monuments, and grave markers.

Claims (1)

[Claims] 1 A resin film layer is formed on a mirror-finished smooth plate, and when this resin film layer is in a semi-cured state,
A piece of photographic paper, which has been dried by peeling off the moisture-proofing resin film to expose the paper part, is placed on top of the semi-cured resin film layer with the photographic image side (front side) facing down. Furthermore, a resin film layer is provided, and photographic paper is inserted between the resin film layers in a sandwich shape while degassing in vacuum. After the resin film layer is semi-cured or hardened, this resin film layer is placed on a smooth plate. Place it in a formwork with the desired shape, and inject a resin liquid containing stone powder onto it under reduced pressure.
Furthermore, the method for manufacturing an artificial stone ornament with a photograph is characterized in that the resin liquid is cured while applying pressure by placing a press plate thereon, and when curing is completed, the smooth plate, press plate, formwork, etc. are removed.