JP2978935B2 - Light-reflective material and its manufacturing method and application - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the Invention] [Industrial application field] The present invention relates to a surface reflection material, various decorative agents, window glass,
The present invention relates to an organic glass product useful as a light reflecting material such as a screen, a lamp shade, and a stained glass. [Prior art] (1) Background Polymethyl methacrylate, methyl methacrylate
Transparent resin plates such as styrene copolymer and polystyrene
Because of its excellent transparency, surface gloss, coloring and weather resistance, it can be used as a decorative material such as a signboard or a display or a roofing material in the form of a transparent material, or as a milky material in which a white pigment is added to the resin material. However, it is widely used as a signboard, a display board, a lighting cover and the like utilizing the scattered light transmittance. In particular, the former polymethyl methacrylate plate material is most widely used because of its particularly excellent properties. (2) Problems of the prior art By the way, in order to further enhance the decorative effect of the transparent resin sheet, in particular, the light transmission and light diffusion properties, Japanese Patent Publication No. 52-16 / 1988 has already been proposed.
As seen in No. 138, a method of forming a foamed sheet by forming an acrylic resin plate by heating and foaming by adding an appropriate amount of water to the raw material has been proposed.
However, according to this known technique, the surface of the obtained foamed water sheet is not only uneven due to bubbles generated during heating and loses surface smoothness, but also the inner wall of the generated bubbles is uneven and poor in gloss. Therefore, even if this is used for the purpose of edge lighting, it is not possible to expect a decorative effect that the entire surface of the surface orthogonal to the incident light shines on average by bubbles. In addition, it is difficult to control the moisture content and obtain a heating method necessary for obtaining a certain foamed sheet, and therefore, it is not practical in terms of production. [Problems to be Solved by the Invention] The problem to be solved by the present invention is to provide a foamed material having a smooth surface, particularly excellent in light diffusion and two-dimensional light transmission, and especially as a surface reflection panel. It is an object of the present invention to provide a novel light reflecting material having a characteristic of emitting beautiful scattered light when used. A secondary object of the present invention is to provide a light reflecting material having an optically arbitrary pattern.

Configuration of the Invention

 (1) Outline In order to achieve the above object, the light reflecting material according to the present invention is used.
The mixture is made up of many small air bubbles inside the transparent organic glass molded body.
The air bubbles are unevenly distributed. Further, the method for producing the light reflecting material according to the present invention is based on an organic glass model.
Nomer and particulate resin consisting of the monomer are mixed and
After foaming and gelling, the gelled material is placed in a cell.
Can be cured together with the same type of liquid organic glass material
And features. The following items are classified according to the main items related to the structure of the invention.
I will explain. (2) Material The organic glass material used for the light reflecting material of the present invention is
Polymethyl methacrylate, methyl methacrylate
Styrene copolymer, polystyrene, etc.
But especially the first polymethyl methacrylate is transparent
Is the best existing material in terms of properties, gloss, weather resistance, etc.
You. (3) Shape and Structure The light reflecting material of the present invention is generally desirably plate-shaped.
But, if desired, curved plate, cylindrical, cylindrical, conical,
Elliptic prism, prism, pyramid, sphere, etc.
Can be presented. However, as a characteristic configuration,
It has a large number of small bubbles unevenly distributed therein. Here, the meaning of the word "discretely distributed" is shown in FIG.
As shown in FIG. 5, the bubbles 3 are formed on one side of the material 2 as a whole.
(Fig. 1) or part (Figs. 2 and 3) and central part
(Not strictly) (whole) (Fig. 4) or part (
5). Each of these structures
Both have excellent light diffusion effect for surface reflection
However, from a manufacturing point of view, the structure shown in FIGS. 1 to 3 is advantageous.
It is. As exemplified in the later [Example], FIG.
In the form of FIG. 5 and FIG. 5, the aggregate of bubbles 3 (bubble group)
More arbitrary characters, figures, line numbers, patterns, etc.
Is possible, which can give a unique aesthetic effect
Wear. Each bubble 3 has a diameter of 0.1 to 2 m / m, preferably about 0.2 to 1 m / m.
It is good to be a spherical closed cell. Especially the inner wall of bubble 3
Ideally, it should be smooth. Invention material is formed into a plate shape
The thickness of the bubble group (bubble layer) is the total thickness of the material
Is preferably in the range of 1/10 to 2/3. (4) Manufacturing The light reflecting material according to the present invention is
Methyl methacrylate and methyl methacrylate or its
Form (foam) body consisting of prepolymer and formwork (usually two sheets
Polished glass plates parallel to each other via gaskets
Cured together with non-foaming homogeneous casting material
It is manufactured by However, the former foamed (sex) body
Avoid mixing with non-foaming (degassed) casting materials
Therefore, pre-polymerization to some extent before the latter casting,
At least it is necessary to make it an agar-like gel. Follow
The pre-polymerization to the gel is carried out in a suitable mold separate from the mold.
By performing in the inside of the mold, any
Bubbles with hieroglyphs such as letters, figures, symbols or patterns
It can be a molded article (foam molded article), and this molded article is
It is hardened integrally with the degassing casting material while it is inscribed in the mold.
You can use any letters, figures, symbols or patterns on one side
(Figs. 2 and 3)
3) can be obtained. If desired, the cell
The mold may be directly arranged at any position on the surface. On the other hand, if the shape and size of the gel
(Ie, gel directly on the cell plate without using a special mold)
-Of course, to prevent the material from flowing out of the cell plate
Is necessary), and the resulting molded product is air
It is a laminate of the grouped layer and the bubble-free transparent layer (No. 1).
See figure). In addition, it was cured to the extent that it did not mix with each other
Full or partial foaming on the bubble-free transparent layer (property)
Overlap the body (at least if the foamable layer is not gelled)
After curing to a gel-like body)
By casting and curing the mold material, a resin layer containing bubbles
Sandwiching the transparent resin layer between the top and bottom (or / and left and right)
Products with a switch structure or embedded structure (see FIGS. 4 and 5)
It is also possible to get For reference only,
Table 1 below summarizes the structure. In the above production means, granular resin (beads)
) Can be used for smooth foaming (bubble formation).
It is meaningful to make it fit. That is, the above methyl methacrylate is used with a polymerization initiator.
When radical polymerization is performed by
A phenomenon called the Romsdorf effect occurs, and the polymerization reaction
After the initial lag phase, the reaction rate (R_P) Is natural
Increase numerically. The increase in viscosity occurs later in the log phase.
So it can stir air during the rise
Even so, the viscosity increases rapidly, so control is very high.
Have difficulty. On the other hand, when polymerized granular resin is used,
The apparent viscosity increases due to swelling and dispersion of the particles,
The required amount of air evenly during the power phase
Uniform air bubbles that are the object of the invention
Is obtained. Therefore, the granular resin used here
Means that the smaller the particle size, the greater the apparent viscosity increasing effect
On the contrary, if it is too fine, it will be uniform and spherical when dispersed.
Since it is difficult to obtain the above air bubbles, in practice, the average particle size is 10 to 2000
μm, preferably in the range of 40-1000 μm
Is good. In addition, the molecular weight factor of the granular resin also
In order to obtain uniform and true-spherical bubbles, which are related to quality,
Generally, MFI (under 230 ℃ / 3.8kg load) 0.1 ~ 30
preferable. In addition, the granular poly for forming foaming (property)
Methyl methacrylate (beads) and MMA monomer or
The ratio of the former in the mixture with the prepolymer of
It should be 30-80% by weight. 30% by weight of beads
%, The plasticity of the agar-like gel becomes insufficient and it is determined
It is difficult to keep the shape of
This makes it difficult to obtain a uniform foam. However, the first
For the purpose of obtaining a simple laminate as shown in FIG. 4 and FIG.
The lower limit may not be limited. (5) Other additives (materials) If desired, a material for forming bubbles or a material for forming a transparent layer
Inside, lead glass beads, crystalline zirconia, α-bromna
High refractive materials such as phthalin-containing microcapsules
Bright dye or fluorescent dye or alkaline earth metal sulfide
Additives such as phosphors can be added. Or, JP
A linear hollow portion in accordance with the method described in
Can be provided. By these means, a star-like radiance was gathered all over
Causes various types of fluorescence in the bubble layer depending on the wavelength of the incident light.
Or add a linear glow or flash the light source
When turned off, phosphorescence can be generated when turned off
Etc. can further increase the overall decorative effect.
Wear. [Operation] Referring to the attached FIG. 6, the material 1 of the present invention enters from the end face 1a.
Part of the emitted light L travels straight through the transparent portion 2 to the opposite end face 1b.
From the outside of the system, but mostly reflected on both sides 1c, 1d
And hit the bubbles one after another, and irregular reflection occurs at the interface.
And shine each bubble. The glow of this is theoretically incident
Should decrease in inverse proportion to the square of the distance from surface 1a
However, as a result of the experiment, until the distance D from the incident surface is about 50 cm,
There is no significant change in brightness, and it can withstand practical use up to about 100 cm
I found out. This is because air bubbles are unevenly distributed on one side of the plate
The light reflected from the bubbles compensates for the attenuation to some extent
It is understood that it is. In contrast, bubbles are dispersed throughout the interior of the plate.
Light, the incident light is greatly attenuated, and is not practical
It was confirmed that. Therefore, the existence of the transparent portion 2 without bubbles is present.
It is necessary for the purpose of the invention as a light path. [Example] Hereinafter, a production example and a configuration example of an invention product will be described by way of an example.
However, the examples are, of course, for explanation, and include or extend the idea of the invention.
It is not limited. Production Example 1 100 parts by weight of methyl methacrylate (MMA) monomer
0.1 parts of a polymerization initiator (AIBN) and the like were mixed. This
270μm average particle size polymer
Chill methacrylate (PMMA) (Sumitomo Chemical Industries, Ltd.)
《SUMIPEX BMH >>, and so on)
The mixture was stirred in the release system. Resin particles gradually dissolve with stirring
Air for forming air bubbles, which appears as a viscous slurry
Was embraced. Separately, prepare one polished glass plate that has been washed and dried in advance
And then place the metal anywhere on the glass plate that you want to foam
I put the formwork. Pour the above slurry into this mold
And left at room temperature for 2 hours to solidify into agar
Was removed. In addition, another polished glass plate that has been washed and dried in advance
Prepare the above glass through a polyvinyl chloride gasket.
The mold was assembled in parallel with the metal plate. On the other hand, 100 parts of MMA monomer and 0.1 part of an additive such as an initiator were added.
After placing in a pre-polymerization tank and pre-polymerizing at 65 ° C for about 1 hour,
The mixture was suctioned and degassed at about 30 to 50 mmHg to obtain a casting syrup.
This syrup is poured into the mold, and the inlet is sealed and removed.
After foaming, polymerize at 55-60 ° C in a thermostat,
Heat treatment was performed in a warm bath to complete the polymerization. The obtained polymer is gradually cooled to 40 ° C and annealed.
After that, the mold was disassembled and the organic glass plate was hardened.
Material), and after cutting the peripheral edge, cut the end face with water
By polishing while cooling, the desired light reflective material product
(See FIG. 2). Production Example 2 100 parts of MMA monomer, 0.1 part of polymerization initiator, etc. were mixed and mixed.
This is mixed with 40 parts of particulate PMMA having an average particle size of 150 μm, and
And stirred until a slurry was obtained. Next, the slurry is poured into a mold having good peelability with the MMA.
The mixture was left at room temperature to solidify. After solidification is complete, carefully remove the solidified material from this mold,
After placing on a polished glass plate that has been washed and dried in advance,
The formwork was assembled as in the example. Separately, reserve 100 parts of MMA and 0.1 parts of additives such as polymerization initiator
Put in a polymerization tank and pre-polymerize at 65 ° C for about 1 hour.
Aspirated and degassed at ~ 50 mmHg. Use this deaerated syrup as above
Inject into the frame and perform curing and post-treatment in the same manner as in the previous example
Thus, the desired light reflecting material product (FIG. 3) was obtained. Production Example 3 100 parts of MMA monomer, 0.1 part of polymerization initiator and the like were mixed and mixed.
The slurry is mixed with 70 parts of particulate PMMA with a particle size of 400 μm.
The mixture was stirred until. Separately, wash and dry a square polished glass plate
A metal formwork of the same shape and size is placed on the edge, and the product thickness
Pour the above slurry until it is half the depth of the
After being left to coagulate at room temperature, the mold was removed. Then, use another glass plate and glass
The formwork was assembled in the same manner as in Production Example 1, and
Inject PMMA syrup prepolymerized into the mold, cure and
After that, a light reflecting material product shown in FIG. 1 was obtained. Product example Fig. 7 shows decorative products obtained using the methods of Production Examples 1 and 2.
FIG. 8 is a front view of an example of the light reflecting material, FIG.
It is arrow sectional drawing which follows X. The product 1 'in this example is a colorless transparent PMMA square plate
A hollow heart-shaped bubble layer 3 is integrally formed
Things. Edge lighting from the lower end face 1'a of the decorative body 1 'of this example
, The hollow heart-shaped figure has almost the same brightness
And presents a fantastic aesthetic that emerges in a dark background.
However, if you look closely, the magnitude of the luminance in the figure is
As indicated by the width of the stippling, the brightness range
Along the inner edge of the hollow part
Each has a slightly unclear ring-shaped bright band 4 '
Is observed, but as a whole gives a sense of asymmetry
is not. The light source is arranged linearly through an optical fiber.
Laser light is ideal, but practically a slit
A fluorescent lamp squeezed linearly at is sufficient. EL issuance board
As the light intensity is insufficient even with a barter,
Not very appropriate.

【The invention's effect】

As described above, the present invention not only has excellent surface smoothness and light diffusibility, but also provides a novel light reflecting material having a characteristic of emitting beautiful scattered light, especially when edge-lit, It can contribute to expanding the use of organic glass and enriching consumer life.

[Brief description of the drawings]

1 to 5 are schematic sectional views showing various structures of the inventive light reflecting material, FIG. 6 is a schematic sectional view illustrating the principle of the invention, and FIG. 7 is decoration according to the invention. FIG. 8 is a front view showing an example of a material, and FIG. 8 is a sectional view taken along the line XX in FIG. The meanings of the reference numerals in the figure are as follows:-1,1 ': the entirety of the inventive light-reflective material;-1a to 1d: each end face of 1, 1';-2: 1, 1 'transparent portion, 3: The same bubble (or bubble layer); 4,4 ': 1' bright band. L: Ray.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 G02B 5/00-5/02 B29C 39/00-39/44

Claims (7)

(57) [Claims] 1. An organic glass monomer and a particulate resin comprising the monomer are mixed and foamed and gelled, and then the gelled material is integrally cured with the same kind of liquid organic glass material in a state of being placed in a cell. A light-reflective material, which is obtained by causing a plurality of small bubbles to be unevenly distributed inside a transparent organic glass molded body. 2. The light-reflecting material according to claim 1, wherein the small air bubbles forming the air bubble group are independent of each other and have a smooth spherical inner wall. 3. The light-reflecting material according to claim 1, wherein the air bubbles form a letter, figure, symbol or pattern. 4. The light reflecting material according to claim 1, wherein the organic glass is polymethyl methacrylate. 5. An organic glass monomer and a particulate resin comprising said monomer are mixed and foamed and gelled, and then the gelled material is integrally cured with the same kind of liquid organic glass material in a state of being placed in a cell. A method for producing a light-reflecting material, characterized by obtaining a light-reflecting material in which bubbles formed from a large number of small bubbles are unevenly distributed inside a transparent organic glass molded article. 6. An organic glass monomer and a particulate resin comprising said monomer are mixed and foamed and gelled in a mold having a predetermined shape, and then the gelled material is decoratively or irregularly placed inside the cell. Inject the same type of liquid organic glass material in the arranged state,
The method for producing a light reflecting material according to claim 5, which is cured. 7. A decorative panel comprising the light reflecting material according to claim 1.