JPS62101437A - Manufacture of hologram decorative resin molded shape - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a hologram decorative resin molded product, and more specifically, an object of the present invention is to easily and inexpensively provide a resin molded product having a hologram on the surface. do.

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

As a method of imparting a hologram to the surface of a resin molded product, (1) a hologram unevenness is provided in advance on the surface of a mold such as injection molding, and the hologram is added to the surface of the resin molded product at the same time as the injection molding. Method of transferring shapes, (2)
(3) A method of forming a layer made of photosensitive resin on the surface of a resin molded product and directly forming a hologram with a laser beam, etc.
Known methods include thermally transferring the uneven shape of a hologram onto the surface of a resin molded product using a hologram transfer sheet, or pasting a hologram sticker.

(Problems to be Solved by the Invention) In the method (1) above, the manufacturing cost of the mold is high because the uneven shape of the hologram is extremely fine, and it is unsuitable for small-scale production. It is necessary to change the mold each time, and furthermore, it is difficult to accurately represent the uneven shape of the hologram in ILF, so it is not industrially practical. In addition, in the method (2) above, it is necessary to irradiate each resin molded product with a laser beam, and the laser beam irradiation equipment etc. are expensive, and mass reproduction is not possible. is of low practicality. In addition, in the method of item 1 (3), resin molded products generally have poor heat resistance, so the uneven shape of the hologram may be deformed by the heat during thermal transfer, or air bubbles may be mixed into the transfer surface during transfer. Various problems arise, such as the fact that dust may adhere to it and it is easy to peel off after transfer or adhesion. Furthermore, as a result of heating one side of the resin molded product, deformation such as warping 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 at low cost and easily.

(Means for Solving the Problems) As a result of intensive research in order to solve the problems of the prior art described above and achieve the object of the invention described above, the present inventors found that a conventional method for casting synthetic resins The present invention was made based on the knowledge that the object of the present invention can be achieved by attaching a hologram transfer sheet to at least a part of the inner surface of the mold in advance and transferring the hologram image at the same time as casting. completed.

That is, the present invention provides a method for manufacturing a resin molded article by injecting a polymerizable resin liquid into a mold and polymerizing and curing the polymerizable resin liquid, which includes pasting a hologram transfer sheet on at least a portion of the inner surface of the mold. This is a method for producing a holographic decorative resin molded article, which comprises applying the resin to the resin molding, polymerizing and curing the polymerizable resin liquid, and transferring a hologram image to the resin molded article.

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

That is, in the method of the present invention, as shown in FIG. 1, it is necessary to prepare a mold material l for casting and provide a hologram transfer sheet 2 on at least a portion of the surface thereof.

Next, a casting mold 3 as shown in FIG. 2 is formed using at least one of the mold materials 1 having the hologram transfer sheet 2 formed as described above, and polymerization is carried out in the voids of the mold. Polymerizable resin liquid 4 is injected, the polymerizable resin liquid 4 is polymerized and cured under appropriate conditions, and after the polymerization and curing, the formwork 1.1' is removed, and then the release sheet of the hologram transfer sheet is peeled off to remove its surface. A resin molded product 6 as shown in the third figure is obtained which has a hologram image 5 on at least a portion of the resin molded product 6.

The above is the basic aspect of the production method of the present invention, and the polymerizable resin liquid used in the method of the present invention is a vinyl monomer that is liquid at room temperature, such as (meth)acrylic acid ester or a mixture thereof, or a vinyl monomer that is liquid at room temperature, Polymerized syrup-like prepolymers are most preferred, and these monomers or syrups contain radical polymerization initiators such as peroxides, hydroperoxides, and azo compounds as necessary components, and other optional components. It may also contain additives such as various colorants, fillers, flame retardants, stabilizers, plasticizers, and other compatible or copolymerizable synthetic resins or vinyl monomers. All of these vinyl monomers or syrups are well known in the art of conventional casting and are readily available commercially for use. Further, the conditions for polymerization and curing of these sulfurs and syrups may also be in accordance with the prior art.

Further, the formwork material used in the present invention can be any material as long as at least its surface is inert to the polymerizable resin liquid. For example, a glass plate, a metal plate, a plastic plate, etc. can be used. Also, the shape of the formwork made of these materials may be flat, prismatic, or any other shape.

Further, in the present invention, the hologram transfer sheet I provided on at least a part of the inner surface of the mold as described in 1- is fully disclosed in many prior application specifications by the applicant, and these are disclosed in the present invention. All are useful in the invention. For those hologram transfer sheets I (the final configuration is as shown in Fig. 4), a 1.111 layer 8 is provided on the peeling sheet 1-7-1 according to the need for peace of mind, and the surface has irregularities of porogranoid. A resin layer 10 having a shape 9 is provided, a reflective metal layer 11 is provided on the uneven surface of the resin layer, and an adhesive layer 12 is provided on the metal layer-1- as necessary.

The following is the basic structure of the hologram transfer sheet used in the present invention. However, in the hologram transfer sheet described in -1-, the hologram image is spread over the entire surface of the peeling sheet i, unlike the illustrated example. Of course, it may be provided partially without being provided, or may have a pattern printed with general printing ink, overlapping or not overlapping with the hologram image.

The hologram transfer sheet 2 as described in 2 is made of the following materials.

The release sheet 7 is a sheet whose surface has a releasability to the extent that it can be easily peeled off and attached to the hologram layer 10 or the release layer 8 (which also serves as a protective layer after transfer) formed as necessary on the hologram layer 10 or its surface. Any known material may be used as long as it is a shaped material, such as plastic films such as polyethylene terephthalate, polypropylene, polyI tyrene, polyamide, etc., releasable films prepared by coating these films with a release agent, and even the above-mentioned materials. Kraft paper, glassine paper, parchment paper laminated with a film such as the following can be used, and any of these films and papers treated with silicon can be used. The thickness of such a peeling sheet is not particularly limited as long as it has appropriate strength and heat resistance, but it is generally 50 to 200 km thick.

- The synthetic resin for forming the synthetic resin layer 10 on the release sheet 1-71 may be any synthetic resin as long as it can provide the holographic uneven shape 41 on its surface.

Such resins include thermoplastic synthetic resins such as polyvinyl chloride, acrylic resins (e.g. polymethyl methacrylate-1, etc.), polycarbonate, polystyrene, etc., or thermosetting synthetic resins such as unsaturated resins. Polyester, melamine, epoxy, polyester (meth)acrylate [herein, (meth)acrylate
]・ is meant to include both acrylate and methacrylate. ], urethane (meth)acrylate, epoxy (meth)acrylate, polyether (
Examples include meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, and triazine (meth)acrylate. Alternatively, the above thermoplastic synthetic resin and thermosetting synthetic resin may be used in combination.

Furthermore, such synthetic resins are particularly suitable for forming the uneven shape of a hologram by heat pressing, and after forming, they harden to provide sufficient durability, such as so-called ultraviolet curable resins, electron beam curable resins, etc. Preferred are reactive resins, thermosetting resins, naturally curing type reactive resins, and the like.

Particularly preferred are resins with aging formations that cure with UV or electron beams, such as 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, ethylene glycol di(meth)acrylate
Acrylate, polyethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate!・
, trimethylolpropane tripane di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, diventaerythritol hexa(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, polyethylene glycol Radically polymerizable unsaturated groups such as di(meth)acrylate, propylene glycol diglycidyl ether di(meth)acrylate, polypropylene glycol diglycidyl ether di(meth)acrylate, and turdo 1-lutetraglycidyl ether tetra(meth)acrylate. A monomer having the following is used.

Further, as an ultraviolet or electron beam curable resin having thermoformability, the following methods (a) to (d) can be used for polymers obtained by polymerizing or copolymerizing the following compounds (1) to (8).
A material having a radically polymerizable unsaturated group introduced therein is used.

(1) Monomer weight N-methylol (meth) having a hydroxyl group
Acrylamide, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, etc.

(2) Monomers having a carboxyl group: (meth)acrylic acid, (meth)acryloyloxyethyl monosuccinate, etc.

(3) Monomer nigericidyl (meth) having an epoxy group
acrylate etc.

(4) Monomers having an aziridinyl group = 2-aziridinylethyl (meth)acrylate, allyl 2-aziridinylpropionate, etc.

(5) Monomers having an amino group: (meth)acrylamide, diaseptone (meth)acrylamide, dimethylamine ethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc.

(6) Monomer having a sulfone group: 2-(meth)acrylamido-2-methylpropanesulfonic acid, etc.

(7) Monomers with isocyanate groups: 2,4-toluene diisocyanate and 2-hydroxyethyl (meth)
Adducts of diisocyanates and radically polymerizable monomers having active hydrogen, such as 1 mol to 1 mol adducts of acrylate.

(8) Furthermore, in order to adjust the glass transition point of the above copolymer and the physical properties of the cured film, the above compound and the following monomers that can be copolymerized with this compound are added. can be copolymerized. Examples of such copolymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and isobutyl (meth)acrylate.
meth)acrylate, t-butyl(meth)acrylate, isoamyl(meth)acrylate, cyclohexyl(
Examples include meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like.

Next, the polymer obtained as described above is reacted by methods (a) to (d) described below to introduce a radically polymerizable unsaturated group, thereby obtaining an ultraviolet or electron beam curable resin. .

(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 monomer having the aforementioned 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 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 or a monomer having an aziridinyl group or a diisocyanate compound and a hydroxyl group-containing acrylic acid ester monomer The addition reaction may be carried out using a 1:1 molar ratio of adducts.

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

The above materials can be sufficiently cured by electron beam irradiation, but when curing by ultraviolet irradiation, benzoin ethers such as benzoquinone, benzoin, and benzoin methyl ether, and halogenated acetophenones are used as sensitizers. A material that generates radicals when irradiated with ultraviolet rays can also be used.

The thickness of the synthetic resin layer 10, that is, the hologram layer, is as follows:
0.1-100 lm, preferably;5.・~30pm.

One surface of the synthetic resin layer 10 has a hologram uneven shape 9
form. This concavo-convex shape 9 is used to reproduce a hologram using reproduction light, and actually has a pitch of 0.1 to 20 lm and a height difference of concavities and convexities of 0.01 to Igm. Such a concavo-convex shape is formed by hot pressing or the like, which is the reverse of the concave-convex shape of the mold surface of a hologram original plate (master plate) created in advance.

A light reflective metal layer 1 is provided on the surface where the uneven shape 9 is formed.
1 are stacked. The light reflective metal layer 11 is the hologram layer 1
Cr, Ti,
Fe, Go, Ni, Cu, 8g, Au, Ge,
An, Mg, Sb, Pb, Pd, Cd, Bi, Sn
, Se, In, Ga, Rh, etc., and their oxides, nitrides, etc. alone or in combination of two or more thereof.

Among these metals, Gr, Ni, Ag, A
Particularly preferred are u and the like.

To form such a light-reflective metal layer 11 on the surface of the hologram layer 10, a metal or an alloy as described above is prepared and then sputtered, vacuum deposited, ion-bladed, or electroplated. The film may be formed by a conventionally known method such as the method. The thickness of the light-reflective metal layer 10 is 10 to 1,000 angstroms, preferably 200 to 2,000 angstroms, more preferably L
<Ha is 300 to 500 angstroms.

In the case of a normal hologram transfer sheet, a heat-sensitive adhesive layer 12 is formed on the surface of the above-mentioned light-reflective metal layer 10, and it can be used as is in the present invention. However, in the method of the present invention, since casting is performed using a liquid polymerizable resin solution, such an adhesive layer does not need to be provided.

Further, in order to improve the adhesion between the hologram image transferred after casting and the molded article, it is preferable to provide an adhesive layer 12 on the surface of the light-reflecting metal layer 10.

As the adhesive resin forming the adhesive layer 12, any conventionally known adhesive resin can be used, such as rubber resins such as polyisoprene rubber, polyisobutyl rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber,
(Meth)acrylic acid ester resin, polyvinyl ether resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polystyrene resin, polyester resin, polyamide resin, polychlorinated olefin resin, polyvinyl Any adhesive resin such as butyral resin can be used, and various additives such as softeners, fillers, and anti-aging agents can also be added as necessary. All of these adhesive resins are commercially available and can be easily used. Particularly preferred adhesive resins in the present invention are acrylic resins and various acrylic modified resins when the polymerizable resin liquid is acrylic. By using this, the hologram image can be more fully integrated into the molded article.

An organic solvent is added to the adhesive resin as necessary to adjust the viscosity, and the light-reflecting metal layer is coated by a conventional coating method such as roll coating, gou coating, knife coating, or gravure coating. 9 to form an adhesive layer 12. The adhesive layer 12 formed in this manner may have any thickness, but is generally preferably formed to a thickness corresponding to about 1 to 50 g/rn' (solid content).

The hologram transfer sheet 2 used in the present invention basically has the following two configurations.

The example schematically shown in FIG. 4 is an example in which a light-transmitting retainer MR8 (release #R) is provided between the hologram RIO of the hologram transfer sheet and the release sheet 7.

The protective layer 8 protects the hologram layer 10 after transfer and improves the releasability between the release sheet 7 and the hologram layer 10 during transfer, and can be called a release layer if releasability is considered important. Of course, both a protective layer and a release layer may be provided.

The protective layer and/or the release layer 8 may be made of any material that is sufficiently translucent, such as cellulose resin, (meth)acrylic acid ester resin, JJJ vinyl resin, Layers formed by various coating methods from paints made of resins such as vinyl acetate resins, urethane resins, melamine resins, polyester resins, etc. alone, mixtures, and copolymers, as well as resins in which various additives are added. But that's fine. These protective layers 8 have a thickness of 0.05 to 1
0ILm, preferably 0.1-571. A thickness of about 100 m is preferable. Such a protective layer 8 can also be colored with a dye or pigment in a conventional manner to make it translucent.

The method of providing the hologram transfer sheet 2 as described above on at least part of the inner surface of the molds l and 1' is to apply the adhesive of the hologram transfer sheet to an appropriate position on the mold material before assembly or on the inner surface of the mold after assembly. Just attach it so that the layer is exposed to the surface. The adhesive used and the attachment method may be any conventionally known method.

As mentioned above, the hologram transfer sheet 2 is transferred to the formwork material 1.1.
' The adhesive layer 12 of the transfer sheet may be provided on the inner surface of the transfer sheet, and by assembling these, a formwork of any shape may be formed.Also, after assembling the formwork from the formwork materials, The adhesive layer of the transfer sheet may be provided on the inner surface.

The main feature of the present invention is to use a mold 3 provided with such a hologram transfer sheet 2. Using such a mold, a polymerizable resin liquid 4 is injected into the mold and polymerized and hardened. Any method for obtaining the resin molded product 6 can be based on a conventionally known casting method. As a typical example, when using methyl methacrylate-based polymerizable resin liquid as the polymerizable resin liquid, the acrylic syrup is injected into a mold, thoroughly defoamed, and heated in a warm bath at about 80 to 100°C. Inside 1
Polymerization and hardening to some extent by soaking for about 5 hours, then 10
By polymerizing and curing for 2 to 5 hours in a curing furnace at a temperature of about 0 to 150°C, a completely polymerized and cured resin molded product can be obtained.

The mold release of the resin molded article obtained as described above and the peeling of the release sheet may be performed according to conventionally known methods. In addition, in such mold release, by firmly adhering the hologram transfer sheet to the mold, the release sheet can be peeled off at the same time as the # mold. The hologram image 5 from the hologram transfer sheet provided on the mold is transferred to at least a portion of the surface of the resin molded product 6 from which the release sheet has been peeled off in this manner.

As described above, by the method of the present invention, a desired holographic decorative resin molded article is obtained, and this resin molded article has a three-dimensional image formed by a hologram on its surface.

(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 as in conventional injection molding. Since a polymerizable resin liquid of 1 is used, the uneven image of the hologram is transferred well.

In addition, unlike conventional technology, the uneven shape of the hologram is not formed on the surface of the resin molded product once it is molded, but the uneven image of the hologram is formed on the surface of the resin molded product at the same time as casting, so it is easier to process. It is also simplified and very economical.

In addition, when applying a holographic uneven image to a resin molded product by thermal transfer as in the past, the heat during transfer may cause the resin molded product to warp if it is plate-shaped. This method could not be applied to some molded products, or the hologram image and molded product would not be integrated and would separate, but according to the present invention, no matter what shape the molded product has, In addition, even if the resin molded product has low heat resistance, a hologram image can be easily placed on the surface of the resin molded product without any problems, and [the L hologram images are sufficiently similar to the molded product]. Because it is integrated into
It won't peel off, get damaged or wear off afterward.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 Polyester film with a thickness of 80 pLm - vinyl chloride -
The solid content of the mixed solution of vinyl acetate copolymer and acrylic resin is 1g/rr? Then, an acrylic melamine-based ultraviolet curable resin was applied to a thickness of 20 pLm using a roll coater, and the uneven shape of the hologram was preformed on this surface to form a hologram master plate. The curable resin was polymerized and cured by irradiating it with ultraviolet rays while it was in close contact, and the uneven shape of the hologram was transferred. Next, aluminum was deposited on the entire surface to a thickness of 400 angstroms using a vacuum deposition method, and then a solution of vinyl chloride-vinyl acetate copolymer was applied to the surface at a solid content of 1.5 g/d. An adhesive layer was formed thereon to obtain a hologram transfer sheet used in the present invention.

Next, this transfer sheet was temporarily fixed to a 2 mm thick glass plate with the adhesive layer exposed outside. Use this glass plate and another glass plate as formwork materials, and place a thickness of 5 mm between the glass plates with the transfer sheet on the inside.
I! A gasket made of vinyl chloride resin (I11) was sandwiched and fixed to form a formwork.

Next, a colored methyl methacrylate polymeric resin liquid with a viscosity of 100 to 200 cps was injected into this mold, and the mold was sealed.
The polymerizable resin liquid was polymerized and hardened by immersing it in a hot bath at 130°C for 1 hour, and then sufficiently polymerized and hardened in a curing oven at 130°C for 30 minutes.

After cooling, the mold was opened, the solidified acrylic resin plate was taken out, and the polyester film attached to its surface was peeled off to obtain a hologram decorative resin molded product according to the present invention. The surface of this resin molded product had excellent three-dimensional visibility due to the hologram.

Furthermore, in the above method, if the hologram transfer sheet is firmly adhered to the glass plate with an adhesive, the polyester film of the transfer sheet can be peeled off from the molded product at the same time when the mold is opened.

[Brief explanation of drawings]

FIGS. 1 to 3 are diagrams schematically showing the Seikan 1!11 method, and FIG. 4 is a diagram schematically showing a cross section of an example of a hologram transfer sheet used in the present invention. 1, 1′; Formwork material 2; Hologram transfer sheet 3: Formwork 4; Polymerizable resin liquid 5; Hologram image 6; Molded product 7; Release sheet 8; Release layer 9; Uneven shape 10; Synthetic resin layer 11; Reflective metal layer 12; adhesive layer Fig. 1 Fig. 3 Fig. 2 Fig. 4

Claims (4)

[Claims] (1) In a method for manufacturing a resin molded article by injecting a polymerizable resin liquid into a mold and polymerizing and curing the polymerizable resin liquid, a hologram transfer sheet is attached to at least a part of the inner surface of the mold, A method for producing a hologram decorative resin molded article, which comprises polymerizing and curing a polymerizable resin liquid and transferring a hologram image to the resin molded article. (2) Claim No. 1, wherein the uneven shape of the hologram image is formed of an ultraviolet or electron beam curable resin.
The manufacturing method described in section. (3) The manufacturing method according to claim (1), wherein the polymerizable resin liquid is an acrylic polymerizable resin liquid. (4) The manufacturing method according to claim (1), wherein the adhesive layer of the hologram transfer sheet is made of an acrylic resin.