JPH0722985B2 - Method of manufacturing hologram decorative resin molded product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a hologram decorative resin molded product, and more specifically, to provide a resin molded product having a hologram on its surface easily and at low cost. To do.

(Prior Art) Conventionally, various resin molded products have been widely manufactured and used, and various colorings and patterns have been imparted to these resin molded products to enhance the cosmetic and design effects. As a means for imparting such cosmetic and design effects, it is also practiced to impart a hologram that gives a three-dimensional visual sensation to the surface of the resin molded product.

As a method of imparting a hologram to the surface of a resin molded product, (1) a concave and convex shape of a hologram is provided in advance on the surface of a mold such as injection molding, and at the same time as the injection molding, the concave and convex of the hologram is formed on the surface of the resin molded product. How to transfer the shape,
(2) A method of forming a layer made of a photosensitive resin on the surface of a resin molded product and directly forming a hologram with a laser beam or the like,
(3) A method in which a hologram transfer sheet is used to thermally transfer the uneven shape of a hologram onto the surface of a resin molded product is known.

(Problems to be Solved by the Invention) In the above method (1), the uneven shape of the hologram is extremely fine, so the manufacturing cost of the mold is high, and it is not suitable for small-quantity production. It is necessary to change the mold for each case, and it is difficult to accurately reproduce the concave-convex shape of the hologram, which is not industrially practical. Further, in the above method (2), it is necessary to irradiate each resin molded product with a laser beam, the laser beam irradiation device and the like are expensive, and mass replication cannot be performed. It is not very popular. Further, in the above method (3), since the heat resistance of the resin molded product is generally poor, the uneven shape of the hologram is deformed by the heat at the time of transfer at the time of thermal transfer, or air bubbles are mixed in the transfer surface at the time of transfer, and dust is generated. It may adhere and cause various problems. Further, as a result of heating one surface of the resin molded product, deformation such as warpage of the resin molded product is likely to occur.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a high quality hologram decorative resin molded product easily and inexpensively.

(Means for Solving Problems) As a result of earnest research to solve the problems of the above-mentioned conventional techniques and to achieve the above-mentioned object of the present invention, the present inventor The present invention has been completed by finding that the object of the present invention can be achieved by forming a concave-convex shape of a hologram in advance on at least a part of the inner surface of the mold and performing casting.

That is, the present invention, in a method for producing a resin molded product obtained by injecting a polymerizable resin liquid into a mold to polymerize and cure the polymerizable resin liquid, a concave-convex shape of a hologram is formed on at least a part of the inner surface of the mold. Holographic decorative resin molding characterized in that a polymerizable resin liquid is provided and polymerized and cured to form a reflective metal layer on the uneven surface of the hologram of the obtained molded product, and a protective layer is provided on the reflective metal layer surface. It is a method of manufacturing a product.

The invention will now be described in more detail with reference to the accompanying drawings, which schematically illustrate the principle of the method of the invention.

That is, in the method of the present invention, as shown in FIG. 1, it is necessary to prepare a casting mold material 1 and to provide at least a part of the surface thereof with the concave-convex shape 2 of the hologram. There are many possible methods for providing the concave-convex shape 2 of the hologram on the surface of the mold material 1, but as a preferable method, a curable resin on a suitable base film 3 such as a polyester film, Preferably, an ultraviolet curable resin or an electron beam curable resin 4 is applied, and a master plate having an irregular shape of a hologram prepared in advance is superposed on the applied surface and irradiated with heat, ultraviolet rays or an electron beam. The curable resin is sufficiently cured, and then the master plate is peeled off to prepare the sheet 5 having the hologram unevenness 2. By adhering the sheet 5 having the hologram unevenness 2 formed in this manner to the mold material 1, the mold material 1 having the hologram unevenness 2 on its inner surface can be obtained. Also, instead of the above method, a mold material, for example, a curable resin as described above is applied on a glass plate via a primer layer as needed, and then a master plate is laminated in the same manner as described above. Similarly, it is possible to obtain a mold material having a hologram uneven shape. As another method, the concave-convex shape of the hologram may be formed by irradiating the curable resin surface with a laser beam according to a conventional method without using the master plate.

Next, a casting mold 6 is formed as shown in FIG. 2 by using at least one mold material having a concave-convex shape of the hologram formed as described above, and the polymerizable resin is placed in the voids of the mold. The liquid 7 is injected, the polymerizable resin liquid 7 is polymerized and cured under an appropriate condition, and the mold 6 is removed after the polymerization and curing, so that at least a part of the surface thereof has a concave-convex shape 2 of a hologram. A resin molded product 7 is obtained. In this state, since the surface of the uneven shape 2 of the resin molded product 7 has insufficient light reflectivity, it is desired to form the reflective metal layer 8 made of, for example, aluminum on the surface of the uneven shape 2 of the hologram. A hologram decorative resin molded product 10 is obtained.

The above is the basic embodiment of the production method of the present invention, and the polymerizable resin liquid used in the above-mentioned method of the present invention is a vinyl monomer which is liquid at room temperature such as (meth) acrylic acid ester or a mixture thereof, or some of them. Polymerized syrup-like prepolymers are most preferred, and these monomers or syrups contain radical polymerization initiators such as peroxides, hydroperoxides, azo compounds, etc. as necessary components, and other optional As a component, various colorants, fillers, flame retardants, stabilizers, plasticizers, other compatible or copolymerizable synthetic resins, or additives such as vinyl monomers can also be contained. All of these vinyl monomers or syrups are well known in the conventional casting technology, and any of them can be easily obtained from the market and used. Also,
The polymerization and curing conditions of these monomers and syrups may be in accordance with the conventional technique.

Further, as the mold material used in the present invention, any material can be used as long as at least the surface thereof is inactive to the polymerizable resin liquid, and for example, a glass plate, a metal plate, a plastic plate or the like is used. The shape of the mold made of these materials may be flat, prismatic or any other shape.

Further, in the present invention, the curable resin used to provide the concave-convex shape of the hologram on at least a part of the inner surface of the mold as described above is thermoformable at the time of molding (reproduction) of the hologram, that is, after the hologram is molded, At the time of use, it is necessary to have resistance to heat pressure during processing and solvent in the adhesive. As such a resin, a so-called ultraviolet curable resin, an electron beam curable resin, a thermosetting resin, a reactive resin such as a naturally curable resin type resin, or the like can be used. In particular, when productivity is taken into consideration, a resin curable with ultraviolet rays or electron beams is suitable.

Specifically, for example, methyl (meth) acrylate [note that the term (meth) acrylate is meant to include both acrylate and methacrylate. The same applies hereinafter], ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isoamyl (meth) acrylate, cyclohexyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol Tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene glycol diglycidyl Radical polymerization of terdi (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol diglycidyl ether di (meth) acrylate, polypropylene glycol diglycidyl ether di (meth) acrylate, sorbitol tetraglycidyl ether tetra (meth) acrylate Monomers having unsaturated groups can be used.

Further, as an ultraviolet ray or electron beam curable resin having thermoformability, a method (a) to be described later can be applied to a polymer obtained by polymerizing or copolymerizing the following compounds (1) to (8).
What introduced the radical polymerizable unsaturated group by (d) is used.

(1) Monomer having hydroxyl group: N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and the like.

(2) Monomer having a carboxyl group: (meth) acrylic acid, (meth) acryloyloxyethyl monosuccinate and the like.

(3) Epoxy group-containing monomer: glycidyl (meth)
Acrylate etc.

(4) Monomers having an aziridinyl group: 2-aziridinylethyl (meth) acrylate, allyl 2-aziridinylpropionate and the like.

(5) Amino group-containing monomer: (meth) acrylamide, diacetone (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the like.

(6) Sulfone group-containing monomer: 2- (meth) acrylamido-2-methylpropanesulfonic acid and the like.

(7) Isocyanate group-containing monomer: Addition of a diisocyanate such as an adduct of 2,4-triene diisocyanate and 2-hydroxyethyl (meth) acrylate with 1 mol to 1 mol and a radically polymerizable monomer having active hydrogen. Things etc.

(8) Further, in order to control the glass transition point of the above copolymer or the physical properties of a cured film, the above compound and the following monomer copolymerizable with this compound And can be copolymerized. Examples of such a copolymerizable monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth).
Acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isoamyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylate etc. are mentioned. Next, the polymer obtained as described above is reacted by the following methods (a) to (d) to introduce a radically polymerizable unsaturated group, whereby an ultraviolet or electron beam curable resin is obtained. .

(A) In the case of a polymer or copolymer of a monomer having a hydroxyl group, a monomer having a carboxyl group such as (meth) acrylic acid is subjected to a condensation reaction.

(B) In the case of a polymer or copolymer of a monomer having a carboxyl group or a sulfone group, the above-mentioned monomer having a hydroxyl group is subjected to a condensation reaction.

(C) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or a monomer having a carboxyl group is subjected to an addition reaction.

(D) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group, a monomer having an aziridinyl group or a diisocyanate compound and a hydroxyl group-containing acrylic acid ester unit amount The addition reaction of 1: 1 mol of the body may be carried out.

Further, the above-mentioned monomer and the thermoformable ultraviolet ray or electron beam curable resin may be mixed and used.

Further, although the above can be sufficiently cured by electron beam irradiation, when cured by ultraviolet irradiation, as a sensitizer, benzoquinone, benzoin, benzoin ethers such as benzoin methyl ether, halogenated acetone phenones, etc. Those which generate radicals by irradiation with the ultraviolet ray can also be used.

A preferred example of the method for forming the concave-convex shape of the hologram using the curable resin as described above will be explained. A suitable base film, for example, polyester, polyamide, polypropylene, polyethylene, vinylon having a thickness of about 30 to 200 μm. 1 to 100 .mu.m, preferably 10 to 30 .mu.m, on the film such as UV curable resin or electron beam curable resin having thermoformability or thermosetting resin having thermoformability as described above.
Is provided to form the hologram forming film.
Among the above resins, an ultraviolet ray or electron beam curable resin which is solid at room temperature before curing and has thermoformability is preferable.

Next, the obtained hologram-forming film and the master plate on which the uneven shape of the hologram is formed are heated and pressed so that the resin layer of the film is in contact with the master plate to form the uneven shape of the hologram on the resin surface. While or after that, the resin is cured by irradiating ultraviolet rays or electron beams or further applying heat.

When heating and pressing the master plate and the hologram forming film, a heating and pressing means such as a heating roll can be used. At this time, the temperature of the heating roll depends on the kind of resin to be used, the material of the base film, and the thickness. Generally, it is appropriate that the temperature is 100 to 200 ° C, although it varies greatly depending on the conditions. Further, it is preferable that the master plate and the hologram forming film are brought into pressure contact with each other under a pressure of 0.1 kg / cm ² or more, preferably 1 kg / cm ² or more.

At this time, ultraviolet rays or electron beams may be irradiated. Further, the film in which the uneven shape of the hologram of the master plate is molded may be peeled from the master plate and then irradiated again, and the irradiation intensity is preferably such that the resin is sufficiently cured. Irradiation with ultraviolet rays or electron beams needs to be appropriately determined according to the resin used.

The method of providing the film having the uneven shape of the hologram thus formed on at least a part of the inner surface of the mold is performed by a suitable adhesive at a suitable position on the mold material before assembly or on the inner surface of the mold after assembly. It may be attached so that the uneven shape of the hologram appears on the surface. The adhesive and the sticking method used may be conventionally known methods.

Further, by applying a conventionally known release agent such as silicone to the surface of the film having the uneven shape of the hologram formed as described above, the mold release property of the polymerized and cured resin molded product is improved. Can be

As described above, a film having a concave-convex shape of hologram may be provided on the surface of the mold material so that the concave-convex shape of the hologram is the inner surface, and a mold of any shape may be formed by assembling these. After the mold is assembled from the mold material, the concave and convex shape of the hologram may be provided on the inner surface thereof.

The main feature of the present invention is to use a mold provided with such a concave-convex shape of the hologram, and the polymerizable resin liquid is injected into the mold using such a mold, and polymerized and cured to form a resin. Any method of obtaining the product can be based on the conventionally known casting method. As a typical example, when using a methylmethacrylate-based polymerizable resin solution as the polymerizable resin solution, inject these acrylic syrups into the mold, thoroughly defoam, and warm the bath at about 80-100 ° C. A completely polymerized and cured resin molded article can be obtained by immersing it in the inside for about 1 to 5 hours to polymerize and cure to some extent, and then to polymerize and cure in a curing furnace at a temperature of about 100 to 150 ° C. for 2 to 5 hours.

The method of releasing the resin molded product obtained as described above may be performed according to a conventionally known method.

The uneven shape of the hologram provided on the mold is transferred in reverse on at least a part of the surface of the released resin molded product, and in this state, the uneven shape of the hologram does not have sufficient light reflectivity. Therefore, it is necessary to provide the light-reflecting metal layer 8 on the uneven surface of these holograms.

The light-reflective metal layer 8 is for imparting light reflectivity to the concave-convex shape 2 of the hologram, and is made of Cr, Ti, Fe, Co, Ni,
Cu, Ag, Au, Ge, Al, Mg, Sb, Pb, Pd, Cd, Bi, Sn, S
It is formed using a metal such as e, In, Ga, or Rb and its oxide, nitride, or the like alone or in combination of two or more kinds. Among these metals, Al, Cr, Ni, Ag, Au and the like are particularly preferable.
The film layer of the light-reflecting metal layer is preferably 10 to 800 angstroms, and preferably 200 to 500 angstroms. Such a light-reflecting metal layer can be easily formed by a conventionally known metal thin film forming technique such as a vacuum deposition method, a sputtering method, an ion plating method.

As described above, according to the method of the present invention, a desired hologram decorative resin molded product is obtained, and this resin molded product has a three-dimensional image formed by holograms on its surface. Although it can be used for applications, the durability of the surface may be required depending on the applications, so for the purpose of protecting the above-mentioned reflective metal layer, on the surface of the reflective metal layer, a reflective metal layer of It is preferable to form a protective layer 9 (FIG. 3) that does not interfere with light reflectivity.

Such a protective layer 9 can be easily provided by forming a film with a transparent synthetic resin coating or laminating a transparent film. Of course, these protective layers may be colored in any hue as long as they are translucent, and by forming a highly transparent colored protective layer,
It is possible to make the stereoscopic sensation by the hologram more preferable. As paint, vinyl chloride-vinyl acetate copolymer resin, nitrocellulose-based, polyurethane-based,
Clear lacquers such as polyester and acrylic are suitable. The thickness of these protective layers varies depending on their respective uses and is not particularly limited.

Although the method of the present invention has been described in detail above with reference to its preferred examples, the method of the present invention is not limited to the above-exemplified method, of course, and various modification methods, modification methods and other aspects of the present invention as described below, for example. Any of the methods including is included in the present invention.

For example, as a method of forming the uneven shape of the hologram, a method of forming the uneven shape of the hologram with a laser beam is also possible. As a method of providing the concave-convex shape of the hologram on the inner surface of the mold by an embossing method or a method using a laser beam, as described above, a film having the concave-convex shape of the hologram is prepared, and the film is attached to the inner surface of the mold. A curable resin layer as described above is provided on the surface, and an embossing method using the layer or a method for forming a concave-convex shape of a hologram by a laser beam is used. Further, a conventionally known hologram transfer sheet is used to form an inner surface of a mold. Of course, a method of transferring the uneven shape of the hologram is also possible. When the mold material is a thermoformable plastic material, the concave-convex shape of the hologram may be formed on the mold material itself.

(Operation / Effect) According to the present invention as described above, the method of the present invention is very economical because it is not necessary to prepare an expensive mold unlike the conventional injection molding, and unlike the injection molding method, Since the above polymerizable resin liquid is used, the uneven shape of the hologram can be reproduced well.

Further, unlike the prior art, the uneven shape of the hologram is not formed on the surface of the resin molded product once molded, but the uneven shape of the hologram is formed on the surface of the resin molded product at the same time as casting, so that it is possible to process Is also simplified, and by using the same mold, a large number of plural products can be made, which is very economical.

Further, when the uneven shape of the hologram is imparted to the resin molded product by thermal transfer as in the conventional case, the heat of the transfer causes warping of the resin molded product when the resin molded product is a plate-like resin. This method cannot be applied to some molded articles, but according to the present invention, even if the molded article has any shape, and even if it is a resin molded article having low heat resistance, the resin can be used without any trouble. The uneven shape of the hologram can be easily provided on the surface of the molded product.

Next, the method of the present invention will be described more specifically with reference to examples.

Example 1 An ultraviolet curable resin was applied to a thickness of 20 μm on a biaxially stretched polyester film having a thickness of 20 μm, and ultraviolet rays were applied while a master plate on which irregularities of holograms were previously formed was adhered. Irradiate to polymerize and cure the curable resin,
A polyester film having a hologram irregular shape was obtained. Next, this film was temporarily fixed to a glass plate having a thickness of 2 mm, with the uneven shape of the hologram on the outside. Using this glass plate and another glass plate as a frame material, a hologram made of vinyl chloride resin with a thickness of 5 mm is sandwiched between the glass plates so that the uneven surface of the hologram is on the inside. , Formwork. Then the viscosity in this mold
Inject 100 to 200 cps of colored methyl methacrylate polymerizable resin solution, seal it, and immerse it in a water bath at 80 ° C for 1 hour to polymerize and cure the polymerizable resin solution. It was polymerized and cured. After cooling, the mold was opened, the solidified acrylic resin plate was taken out, and the polyester film adhering to the surface thereof was peeled off together with the curable resin having the irregular shape of the hologram. Next, 300 aluminum is applied to the uneven surface of the hologram formed on the surface of the molding plate.
It was deposited to a thickness of Angstrom. Further, a thermosetting acrylic resin liquid was spray coated on the surface of the reflective metal layer to form a protective layer, and a hologram decorative resin molded product according to the present invention was obtained. The surface of this resin molded product had an excellent three-dimensional visual sensation due to the hologram.

The polyester film having the uneven shape of the hologram peeled off above could be reused any number of times. Further, in the above method, if the polyester film having the hologram unevenness is firmly adhered to the glass plate with an adhesive, the polyester film having the hologram unevenness can be simultaneously peeled from the molded product when the mold is opened. it can.

Example 2 A mold having an irregular shape of a hologram was prepared by applying an ultraviolet curable resin on a glass plate having a thickness of 2 mm to a thickness of 7 μm, and then using a laser beam to form an irregular shape of a hologram on the curable resin surface. Framed. Then, in the same manner as in Example 1, an acrylic resin plate having a hologram irregular shape and having a thickness of 4 mm was obtained. Then, aluminum was vapor-deposited on the irregular surface of the hologram to a thickness of 300 Å, and a urethane resin was deposited on the vapor-deposited surface. The liquid was spray-coated to obtain a hologram decorative resin molded product according to the present invention. Similar to Example 1, this resin molded product also gave an excellent three-dimensional visual sensation due to the hologram.

[Brief description of drawings]

1 to 3 are diagrams schematically showing the method of the present invention. 1; Form material, 2; Concavo-convex shape of hologram 3; Base film, 4; Curable resin 5; Hologram sheet, 6; Form 7; Polymerizable resin liquid (molded product) 8; Reflective metal layer, 9 Protective layer 10 ; Hologram decorative resin molding

Claims (5)

[Claims] 1. A method for producing a resin molded product, which comprises injecting a polymerizable resin solution into a mold to polymerize and cure the polymerizable resin solution, wherein at least a part of the inner surface of the mold is provided with a hologram uneven shape. And polymerize and cure the polymerizable resin liquid to form a reflective metal layer on the uneven surface of the hologram of the obtained molded product,
A method for producing a hologram decorative resin molded article, which comprises providing a protective layer on the surface of the reflective metal layer. 2. The manufacturing method according to claim 1, wherein the uneven shape of the hologram is provided by attaching a film having the uneven shape of the hologram to the inner surface of the mold. 3. The manufacturing method according to claim 1, wherein a release agent is applied to the uneven surface of the hologram. 4. The manufacturing method according to claim 1, wherein the concave and convex shape of the hologram in the mold is formed of ultraviolet ray or electron beam curable resin. 5. The method according to claim 1, wherein the polymerizable resin liquid is an acrylic polymerizable resin liquid.