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ARTIFICIAL STONE MOLDED PRODUCT
TECHNICAL FIELD
The invention of the present application relates to an
artificial stone molded product. More specifically, the
invention of the present application relates to an artificial
stone molded product which has a night decorativeness, a
luminousness such as a luminescence and a light-emitting property
acccwnpanied by ultraviolet absorption and which is useful in a
building material or a sight material as a direction indicator
or a position guide using light in dark surroundings.
BACKGROUND ART
An artificial stone obtained by pulverizing a natural stone
and mixing the pulverizate with a resin or the like for
solidification has boon so far known. And regarding this
artificial stone, various atternpts have been made to provide a
product having a tons of a natural stone such as marble, granite
or the like and being excellent in a hardness and a strength.
As an approach to improve properties and a performance of
such an artificial stone, there has been also a proposal of
imparting a light function using a luminous material such as a
luminescent material or a fluorescent material such as an
ultraviolet light-emitting material which e:nits light through
ultraviolet absorption. This approach is conducted by mixing a
fluorescent material with a resin component as a binder of an
artificial stone for solidification or by nni.xing a luminescent
fluorescent material such as strontium aluminate or the like or
a ultraviolet fluorescent material with an unsaturated polyester,
a methacrylic resin, a glass or the like for solidification,
pulverizing the mixtura, and using the resulting product as an
aggregate to form an artificial stone.
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However, in the case of the conventional luminous or
fluorescent artificial stone, there were defects that in either
of the above-mentioned methods, it is only in the position where
the binder resin component or the aggregate exposed to the surface
of the artificial stone is arranged that the luminescent material
or the like gives the fluorescent function and the luminescent
material or the like contained in the artificial stone molded
product does not act at all in portions other than the above-
mentioned. A fluorescent material such as a luminescent material
or the like is quite expensive, and even the addition of the same
in a small amount increases the overall cost to from 3 to 10 timas.
Accordingly, the ordinary artificial stone containing therein
a fluorescent material free from this function was not practical
in view of the cost.
Further, a luminous layer formed of a luminesc nt material
on a surface of an artificial stone has been so far mostly spread
throughout the surface. Accordingly, for example, a product is
not one in which only a guide figure or a guide pattern indicating
a direction or a position which is required in dark surroundings
at night is formed of a luminous layer.
Meanwhile, it has also been studied that only a gvide figure
or a guide pattern is formed of a luminous layer as mentioned above.
However, in the casw of the ordinary luminous layer, an adhesion
with a substrate is poor, and the luminous layer itself has a poor
abrasion resistance. Accordingly, there has been a problem that
especially in the application to a floor, a predetermined function
is not provided owing to delamination, dropping, abrasion and the
like of the luminous layer.
For this reason, there have been so far problems that the
application and the design of the luminous artificial stone are
quite limited owing to a high cost and restrictions of a
luminousness and physical properties.
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It has been therefore required to realize a new artificial
stone molded product which is excellent in a luminousness as well
as in an adhesion integrity with a substrate of a luminous layer
and physical properties such as an abrasion resistance and the
like, which has a luminousness or a fluorescence and which is
useful as a light guide or a night decorative material in dark
surroundinqs, while decreasing the cost of the product upon using
a luminous or fluorescent material such as a lumincscont material
or the like only in a figure or a pattern required.
DISCLOSURE OF INVENTION
In order to solve the above-mentioned problems, the
invention of the present application provides an artificial stone
molded product in which protrusions or embedded grooves for a
fiqure or a pattern are provided integrally on or in a flat surface
of a substrate, and a main composition comprises an aggregate of
an inorganic material and a resin, characterized in that
at least a part of the above-mentioned protrusions or
eubedded grooves are luminous or fluorescent light-emitting
portions which contain a luminous or fluorescent material having
a luminescence or a luminousness accompanied by ultraviolet
absorption and an aggregate of a transparent inorganic material,
or an aggregate of a transparent inorganic material having a
surface baked with the above-mentioned luminous or fluorescent
material as a part of the aggregate of the inorganic material.
The present invontion further provides a process for
producing the above-mentioned artificial stone molded product.
BRIEF DESCRIPTION OF THE DRAWINGS
Figures 1 and 2 of the drawings attached are each a sectional
view showing a structure of an artificial stone in the present
invention.
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Figures 3 and 4 are each a flow chart of a process for
producing the same in the present invention.
BEST MOOE FOR CARRYING OUT THE INVENTION
The invention of the present application is described in
more detail below.
The artificial stone molded product intended by the present
invention can be described by referring to, for example, Figures
1 and 2 of the drawings. In the case of Figure 1, an artificial
stone molded product (1) has protrusions (3) on a flat surface
of a substrate (2) , and the protrusions (3) are arranged and formed
to give a predetermined figure or pattern. And this protrusion
(3) is a luminous or fluorescent light-emitting portion having
a luminescence or a luminousness accompanied by ultraviolet
absorption. The substrate (2) itself does not form such a
light-emitting portion.
Zn the case of Figure 2, the substrate (2) is provided with
embedded grooves (4) having embedded therein light-emitting
portions.
The protrusion (3) as light-emitting portions, as shown in
Figure 1, can have, for example, a function of a braille block
in the daytime and a function of a mark for a guide of a direction
or a position in dark surroundings at night. In the case of Figure
2, it is likewise useful as a mark for a guide. Of course, a
decoration at night or the like can also be provided.
As stated above, it is an objQct of the present invcntion
that only the protrusions (3) and the embedded grooves (4) can
selectively become light-emitting portions. In the conventional
art, this was quite difficult. It was largely because the
adhesion integrity between the substrate and the light-emitting
portions is poor and the light-emitting portions themselves have
a poor abrasion resiatancg.
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The present invention is to provide, upon conquerinq such
defects of the conventional art, an artificial stone molded
product which enables the cost to dscrease by the selective
formation of light-eini.ttin9 portions and which prQvonts
delamination, dropping and abrasion.
With respect to the composition of the artificial stone,
in the present invention, it contains an aggregate of an inorganic
material and a resin as basic romponents in the substrate (2),
the protrusions (3) and also the embedded grooves (4) in Figures
1 and 2. In this instance, the aggregate of the inorganic
material includes a wide variety of materials such as a natural
stone, a natural mineral, a synthetic inorganicmaterial, a glass,
a metal and the like.
And what is important in the present invention is that a
luminous or fluorescent material and an aggregate of a transparent
inorganic material or an aggregate of a transparent inorganic
material having a surface layer coated with a luminous or
fluorescent material is contained in at least a part of tho
aggregate of the inorganic material in the light-emitting
portions constituting the above-mentioned protrusions (3) or the
embedded grooves (4).
When the light-emitting portion contains the aggregate of
the transparent inorganic material along with the lumtiinous or
fluorescent material, it is indispensable that the weight ratio
of both materials is between 1:2 and 1:10 and the sum of both
materials is between 80 and 95% by weight based on the overall
composition of the light-emitting portion.
Further, when the light-emitting portion contains the
aggregate of the transparent inorganic material having the
surface coated with the luminous or fluorescent material, it is
indispensable that the weight ratio of this material is between
S and 65% by weight based on the overall composition of the.
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light-emitting portion.
The above-mentioned requirements are defined in view of
physical properties such as a delamination resistance, a drop
resistance, an abrasion resistands and the like, and a
luminousness.
As the aggregate of the inorganic material, a combination
of the following two types is preferable. That is, one is a fine
powder component of an inorganic material having a size of from
to 70 mwsh. This is a fine powder component of an appropriate
inorganic material selected from minerals such as silica, rocK,
chrysolite, feldspar, pyroxene, mica and the like, natural stones
such as granite, metamorphite and the lika, porcelain, glasses,
metals and the like.
And along with this fine powder component, a finely divided
coa-ponent having a size of 100 mesh-under is preferably used. As
this finely divided component, various natural or artificial
finely divided components are mentioned. For example, powders
of calcium carbonate, aluminum hydroxido and silica rock are
easily obtainable finely divided components.
Flsrther, as a part of this finely divided coisqnonent, a
component such as manganese dioxide, titanium dioxide, zirconium
silicate, iron oxide or the like to adjust a color tone, or a
component such as antimony trioxide (pentoxide) , a boron compound,
a bromine compound or the like to impart a flame ratardance and
an incombustibility may be blended.
The above-mentioned fine powder component acts as a main
factor of an appearance and physical properties of the resulting
artificial stone molded product. The size of the finely divided
component is much smaller than the 100 mesh level in comparison
to the fine powder component. The finely divided component
enters between the individual particles of the fine powder
component and is arranged to fill the space between the particles,
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contributinQ toward providing propertiea such as a hardness and
a pliability of the resultting artificial stone. The weight ratio
of the fine powder component and the finely divided component is
preferably between 0. 5:1 and 5:1, more preferably bQtwoen 1:1 and
4:1. A'hen the artificial stone molded article of the present
invention is formed of a cocnbination of the fine powder component
and the finely divided corRponent, the structure of the light-
emitting portion Can be considered as follows.
<A> When the luminous or fluorescent material and the
aggregate of the transparent inorganic material are used as a part
of the aggregate of the inorganic material, it is advisable that
the component of the transparent inorganic material is usec3.as
at least a part of the fine powder component and the luminous or
fluorescent tttztsrial is used as at least a part of the finely
divided component.
The fine powder cotnponent as the aggregate of the
transparent inorganic material refers to a coniponent of an
inorganic material having substantially a high light
transmission. The transparency thereof includes various degrees.
A natural or synthetic inorganic material having a relatively
high light transmission is to be used in the present invention.
Consequently, the fine powder consponent.of the transparent
inorganic material may be colored or have a peculiar color.
Quartz, silica rock, a glass and the like are typically
mentioned in the present invention as the fine powder component
of the transparant inorganic material. However, it is not
limited thereto.
And the artificial stone taolded product of the present
inventi.on contains, as a part of the finely divided component,
a luminous or fluorescent ccnWnent'having a luminescence or a
luminousness accompanied by ultraviolet absorption and having a
size of 100 mesh-under. Typical axacnplas of such a component
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include a strontium aluminate ltani.nescent material, zinc sulfide
and the like. These materials are used in, the present invention.
The fine powder component of the inorganic material which
plays a roll as an aggregate of an artificial stone haa a size
of from 5 to 70 mash as mentioned above, and this is an
indispensable requirement in the combination with the finely
divided component of the inorganic material. And the above-
mentioned luminous or fluorescent component plays the same roll
as the finely divided coMponent, and imparts the light function
such as the luminousness or the fluorescence to the artificial
stone. It is also indispensable that the size of the luminous
or fluorescent component is 100 mash-under as in the finely
divided component.
With respect to each of the above-mentioned components of
the inorganic materials, the mixing ratio is an important
requirement along with its size.
That is, in the aomposition of the artificial stone of t:5e
present invention, the, relationship of the weight (W1) of the
above-mentioned fine powder ccsnponent of the inorganic material,
the weight (Ws) of the finely divided component of the inorganic
material and the weight (Ws) of the luminous or fluorescent
component is preferably as follows.
Wi : (W=+F1,) =0.5:1 to5:1
W2 : W3 = 1:2 to 10:1
With respect to Wi :(Ws + p,) , it is preferably between 1:1
and 4:1. With respect to WZ : W,, it is preferably betwoen 1:1
and 5:1.
And in the fine powder component of the inorganic material,
as mentioned,above, it is advisable that the ratio of the fine
powder component of the transparent inorganic material therein
has preferably the following relationship
(0.5 to 1.0)W=.
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The above-mAntioned facts aro required to realize physical
properties as an artificial stone, such as a strength, a hardness,
a density and the like, and a light function such as a luminousness
or a fluorescence.
Specifically, the size of each component is selected, as
required, depending on a size and a mixing ratio of each component
used in combination. Generally, it is preferable that the size
of the finely divided component and the luminous or fluorescent
component is between 150 and 250 mesh.
The light function of the artificial stone is further
described. With respect to the artificial stone of the present
invention, the light function of the luminous or fluorescent
artificial stone is realized in such a manner that
1) from 30 to 100% by weight of the fine powder component
of the inorganic material is a fine powdar of a transparent
inorganic material, and
2) a luminous or fluorescp-nt component of 100 zswsh-under
is mixed at the above-mantioned specific ratio. And the
characteristic feature in this case is that light can be emitted
as light having a thickness. It is not that light is emitted in
the surface layer alone as in the prior art, but that light is
emitted in the overall thickness of an artificial stone. Thus,
the product is excellent in the luminousness and the economics
in view of the use of an expensive luminous or fluorescent
component.
The reason is aa follows. The use of the fine powder
componpnt of the transparent inorganic material as a traneparent
aggregate permeates light emitted from outside into the inside
of the artificial stone to efficiently absorb the light energy
in the luminous or fluorescent component, and the lulninous layer
having dispersed therein the luminous or fluorescent component
formed of the luminescent material or the like is secured as a
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great thickness including the inside of the artificial stone, so
that a high luminosity can be maintained for a long period of time.
In the light emission, the fine powder component of the
transparent inorganic material coer-as to have a high luminosity
because it is good in a light transmission.
The ratio of the transparent component occupied in the
overall fine powder component is, as mentioned above, between 30
and 100$ by weight. Naturally, in some physical properties of
an artificial stone, such as a strangth and the like and some
external design, a ratio of 100% is preferable from the standpoint
of a light function. Of course, this is not critical. However,
when it is iess than 3U% by weight, a desired light function is
hardly provided.
<B> When the aggregate of the trs.nsparent inorganic material
having the surface baked with the luminous or fluorescent material
is used as a part of the aggregate of the inorganic material, it
can be used such that at least a part of the fine powder component
is transparent, and it has the surface baked with the luminous
macerial having a luminescence or the like or the fluorescent
material having a luminousness accompanied by ultraviolet
absorption. That is, a part or the whole of the fine powder
component is the aggregate of the transparent inorganic material
having the surface coated with the luminous material or the
fluorescent material. Appropriate examples of such an aggregate
of the inorganic material having the transparent light include
a glass, silica rock and the like.
Regarding the fine powder component incorporated in the
coraposition, it is advisable that the ratio (weight) of from 10
to 100% is used in the above-mentioned aggregate of the
transparent inorganic material having the surface layer coated
with the above-mentioned luminous or fluorescent material.
In the aggregate of the transparent inorganic material,
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ospecially, the baked coating of the fine powder component, a
coating having a thickness of from several-iaicrometers to several
tens of mierometers, for example, from S to 50 m, preferably from
20 to 40 (.un is applied to the surface of the particle in the
transparent fine powder componant. More specifically,.the
coating is applied by the baking at a high temperature of from
120 to 1,200 C.
The fluorescent material to be baked can include various
fluorescent materials which have a luminescence or which emit
light through ultraviolet-light irradiation, such as strontium
aluminate, zinc sulfide and the like.
The baking is conducted not by various known methods, but
by mixing the aggregate of the transparent inorganic material,
for example, the above-mentioned fine powder component with a
dispersion or a paste having dispersed therein a fine powder of
a luminescent material such as strontium aluminate or the like
and drying the mixture.
In the present invention, it is advisable that the fine
powder component of the inorganic material has the specific size
as noted above. That is, the fine powder component of the
inorganic material has a size of from 5 to 70 mssh as mentioned
above. When an upper or lower portion is colored dark using the
colored and colorless materials, it is considered that the size
of fine particles is changed depending on the colored or colorless
condition. However, fine particles which are extremely
different in the size shall not be used in large amounts because
they deteriorate the strength of the product.
Meanwhile, the size of particles of the finely divided
cemponent is 100 mesh-under as noted above. The particles of the
finely divided component have to be fully incorporated between
the particles of the fine powder cornponent. More specifically,
the size ia preferably between 150 and 250 mesh.
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And what is ing>ortant in the high-density artificial stone
of the present invention is that the aggregate components of these
inorganic materials are preferably dispersed uniformly in any
portions of the product except in special cases.
E~rther, the resin component can be selected from a wide
variety of thermosetting materials_
For example, an acrylic resin, a methacrylic resin and an
unsaturated polyester resin are mentioned. Of these, the
methaerylie resin is preferable in view of a transparency, a
hardness, a strength and the like. The ratio of the resin
component is proferably less than 15% by weight, further
preferably 10% by waight or less basad on the total composition.
This resin component contributes to covering the fine powder
component and the finely divided component which are components
forming the above-mentti.oned structure to bind the whole body, and
functions to impart a resilience or a tensile strength to a product
when an artificial stone is completad. Tha ratio of the aggregate
of the inorganic material formed of the fine powder component and
the finely divided ecxmponent is limited. That is, it has to be
85$ by weight or more, preferably 89% by weight or more. When
it exceeds 95$, the product becomes brittle and is hard to use.
When it is less than 85%, the product becomes too soft to give
qualities as a stone. Thus, the product is used in the same range
as a resin plate.
This means that the component other than the fine powder
cornponent and the finely divided component such as a natural stone
and the like, namely, the resin component should not be present
in the product in an amount exceeding 15.1 by weight.
When the amount of the resin component exceeds 15%, the
product is like plastics, and it is only seemingly an artificial
stone. Further, when the amount of the resin component is
excessively decreased, a product comes to have an appearance close
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to a natural color, but it becomes brittls and is unsuitable for
actual use. From this standpoint, the amount of the resin
component is more preferably between 5 and 11% by weight.
In practicing the present invention, the ratios of thoa
components are important. Especially important is a ratio of the
resin component to the other component. In the present invention,
one of the characteristic features is that a high-density product
having a dense texture can be providad. The high density here
raferred to means that the fine powder component and the finely
divided component contained in the artificial stone product are
present in a high density. For exwple, this density ia 2.2 g/an'
or more which exceeds the range in the conventional artificial
s tone .
It is advisable that the outer surface of the product is
polished or roughened. In practice, it is preferable that the
broken fine powder component is exposed.
The polishing is a practically convenient method for
exposing the dense texture condition inherent in the high-density
artificial stone having a deep atmosphere in the present invention.
It is, of course, possible that a part of a surface of a product
is polished to expose the fine powder cornponent and a difference
with another portion in the same surface is used as a pattern.
Further, when an artificial stone is obtained, it is an
important problem what a desired color or design is. Granite or
marble is one goal because.a product formed of a natural stone
is hardly obtained and a color and a glaze thereof aro beautiful.
In the present invention, the transparent component is used as
the fine powder component, making it possible to obtain a product
having a glaze of granite, marble or the like. This is because
a fine powder obtained by pulverizing a quartz-type natural stone
is used as the fine powder component.
The fine powder obtained by pulverizing the quartz-type
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natural stone is colorless and transparent in many cases. In a
non-transparent powder, a transparent often remains slightly.
It is also possible to provide a uniform color and a deep,
glazed peculiar tone of color by adding an inorganic pigment, an
organic pigment such as an azo pigment or a phthalocyanine pigmant,
or various dyes.
In the composition of the artificial stone in the present
invention, the product can also be colored by using colored
particles having the same size as tho fine powder component, an
a color component.
In any case, the color reproducibility can be secured quite
easily in comparison to the conventional artificial stono, and
a product which is axcellent in a dept and a.Qlaze without
discoloration can be obtained.
The high-density artificial stone of the present invention
having usually excellent color tone characteristics along with
a luminescence, a ultraviolet light-emitting property and the
like can have any form, examples of the form being a plate, a bar,
a cylinder and the like.
The above-mentioned artificial stone molded product of the
prasent invention can be produced by, for example, the following
process.
<I> Molded product in which protrusions are light-emitting
portions:
Fiqure 3 is a flow chart showing a typical process for
producing an artificial stone molded product (1) in which
protrusions (3) are light-emitting portions.
That is, this Figure 3 shows a process for producing an
artificial stone molded prvduct in which protrusions (3) for a
figure or a pattern are integrally provided on a flat surface of
a substrate (2) , a main composition comprises an aggregate of an
inorganic material and a resin, and at least a part of the
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protrusions (3) are luminous or fluorescent light-emitting
portions, which comprises
injecting a mixture (6) for resin molding containing a
luminous or fluorescent material having a luminescance or a
luminousness accompanied by ultraviolet absorption and an
aggregate of a transparent inorganic material or an aggregate of
a transparent inorganic material having a surface baked with the
luminous or fluorescent material as at least a part of the
aggregate of the inorganic material into grooves (51) of a mold
(5) which correspond to the protrusions (3) of the molded product
and which are formed in the inner bottom surface,
then injecting a mixture (7) for resin molding containing
an aggregate of an inorganic material into the mold (5),
preaa-curing the mixture, withdrawing the product from the mold,
and further polishing the product or roughening the product using
a water jet or the like as required to produce an artificial stone
molded product (1) having light-emitting portions in the
protrusions (3) alone.
In the curing upon fitting a male mold (8) , the compression
is conducted by pressing with a surface pressure of, for examle,
from 5 to 100 kgf/ccm2. In this molding, heating is conducted at
a temperature of from approximately 90 to 140 C for from 5 to 20
minutes in tha compression.
Tha mixture (6) for resin molding which forms the
light-esnitting portions as the protrusions (3) and the mixture
(7) for resin molding which forms the substrate (2) are integrally
molded in the above-mentioned curing step by the compression.
Accordingly, delamination or dropping of the light-emitting
protrusions (3) does not occur. Besides, the protrusions (3) are
also formed as having an excellent abrasion resiatance due to its
cornposi tion .
This process using such a cotnpression molding exhibits a
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mass-production effect as a process for produc.ing a product with
a relatively simple shape, such as a flat molded product, and there
is almost no loss of a material, so that this process is
economically excellent too.
A means for surface polishing is not particularly limited.
It can be conducted using a tool such as a grindstone, a polishing
cloth, a polishing belt or the like, or a polishing agent such
as a buff polishing agent, a rubbing compound or the like.
As the polishing agent, diamond, boron carbide, corundum,
alumina and zirconia which have mainly a polishing action, and
tripoli, dromite, alumina, chromium oxide and cerium oxide which
have mainly a scratching action are used as required.
And in the present invQntion, the surface of the molded
product after the molding may be roughened to expose the finely
divided couponent to the 'surface portion.
To this end, a method of selectively removing the rosin
component is employed. That is, it is effective; for example,
that after the product is removed from the mold, high-pressure
water is jetted on the surface of the molded product to conduct
the texture treatment.
Since this treatment varies dependtng on various conditions
such as a thickness, a distance from a nozzle, a treatment mode
and the like, it is not limitative. However, usually, in the case
of a thickness of from 2 to 20 ean, a water pressure of from 50
to 1,400 kg/czn= can be applied from a height of a noz2lo of froen
2 to 50 cra. This water pres9ura is far lower than when a natural
stone is used.
That is, this is because the high-quality treatment can be
conducted more easily by the presence of a rosin coanponont.
A nozzle for jetting high-pressure water or its system is
not particularly limited. Various types are employable.
The surface is flattened or roughened using the water jet
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in the texture treatment to produce an artificial stone having
a deep quality.
The presence of the resin component does not make the surface
cloudy, and makes easy the treatment of a waste wster in comparison
to an etching method using chemicals.
Naturally, the surface can be treated with an organic
solvent as required to soften or melt the resin component and
partially remove the same.
In this case, the organic solvent correaponding to the resin
component may be selected. Examples thereof include halogenated
hydrocarbons such as methylene chloride and chloroform,
carboxylic acids and esters thereof such as acetic anhydride,
ethyl acetate and butyl acetate, acetone, tatrahydrofuran, DMF
and DM30.
The molded product is dipped in these orQanic solvents or
these organic solvents are sprayed thereon or caused to flow down
thereon to remove the resin component softened or melted from the
surface whereby the uneven surface can be formed.
Alternatively, the uneven surface may be formed by
scratching the resin component having a low hardness from the
surface with a wire brush, a cutting means or the like.
The surface is xoughonoddby the above-mentioned various
means, and the texture is treated. Then, the resulting surface
is polished as noted above to realize the peculiar deep, glazed
surface.
<II> Molded product in which embedded grooves are
light-emitting portions:
Figure 4 is a flow chart showing a typical process for
producing an artificial stone molded product (1) in which embodded
grooves (4) are light-emitting portions.
That is, this Figure 4 shows a process for producing an
artificial stone molded product in which aenbedded grooves (4) for
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a figure or a pattern are integrally provided in a flat surface
of a substrate (2 ), a main composi tion comprises an aggregate of
an inorganic material and a resin, and luminous or fluorescent
light-emitting portions are embedded in at least a part of the
embedded grooves (4), which comprisas
injecting a mixture (7) for resin molding containing an
aggregate of an inorganic material into a mold (5) having
protrusions (52) corresponding to the meibedr3ed grooves (4) of the
molded product in the inner bottom surface, curing or half-curing
the mixture, withdrawing the resulting product from the mold,
injecting a mixture (6) for resin molding containing a
luminous or fluorescent ma.terial having a luminescence or a
luminousness accompanied by ultraviolet absorption and an
aggregate of a transparent inorganic material or an aggregate of
a transparent inorganic material having a surface baked with the
luminous or fluorescent material as at ieast a part of the
aggregate of the inorganic material into grooves formed in the
surface of the molded product to produce an artificial stone
molded product (1) having the light-anitting portions in the
embedded grooves (4) alone.
In this process as well, the curing by compression molding
can be conducted in the above-mentioned manner, and the surface
of the molded product (1) ie likewise finally polished or
roughened as required. The mixtures (6) ,(7) for resin molding
are also integrated.
For example, when the aggregate of the transparent inorganic
material having the surface coated with the luminous or
fluorescent material is used as the mixture (6) for resin molding
in either process, the soctions of the particles and the coating
layer are exposed by treatment such'as polishing or the like.
In this manner also, an artificial stone which is excellent
in light-emitting characteristics, a texture and qualities is
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produced.
That is, for example, when a luminescent or ultraviolet
light-emitting material is baked and coated on the surface of the
fine powder component, the particles of the fine powder component
and the coating thereof are exposed as sections by polishing the
surface of the artificial stone. Consequently, light irradiated
from outside is entered frosn the exposed particle surface of thA
transparent fine powder and reaches the baked coating material
in the inside.
In the case of a highly transparent methacrylic resin or
the like, the light transmission is rendered wholly good.
For this reason, incident light ss transmitted into the
inside of the light-emitting portion, and light is also emitted
from inside.
Accordingly, light can be stored in a short period of time,
and a light-emitting efficiency is also increased.
The present invention is illustrated by referring to the
following Examples. Naturally, the present invention is not
limited to the following Exaunples.
EXAMPLE
Example 1
An artificial stone molded product was produced according
to a process shown in Figure 3.
That is, a mixture (6) for resin mOlding having the following
fozinulation was injected into grooves (51) having a depth of 6
rrm in a mold (5).
Silica rock of from 10 to 50 mesh in which 60% by weight
a surface layer baked with a strontium
aluminate luminescent material at
approximately 11000 C was formed to a
CA 02590599 2007-06-15
thickness of approximately 30 pm
Silica rock powder having an average 30% by weight
particle diameter of 250 mesh
Methyl methacrylate (MM) (containing 10% by weight
0.15$ of a peroxide-type curing agent)
Subsequently, a mixture (7) for resin molding having tha
following formulation was injected into the mold (5).
Silica rock of from 10 to 70 mesh 20-t by weight
Silica rock of from 10 to 70 mesh having 42% by weight
on tho surface a baked layer of a yellow
pigment with a thickness of 30 rn
Aluminum oxide powder having an average 30$ by weight
particle diameter of 225 mesh
Methyl mathacrylate (Hmk) (containing 8$ by weight
0.15% of a peroxide-type curing agent)
An upper mold (8) was placed theroon, and the mixture was
pressed and cured at a temperature of 120 C and a prQSsure of 12
kgf/an2 for 20 minutes.
Then, the product was withdrawn from the mold to obtain an
artificial atone molded product (1) in which the thickness of the
substrate (2) was 20 nsn and the height of each of the protrusions
(3) was 6 mm.
With respect to this molded product (1) , the surface of t.he
protrusion (3) was adjusted to a height of 5 nan by polishing the
same with a diamond grindstone.
In the resulting molded product (1), the protrusion (3)
polished had a light-emitting property such as a luminousness,
and exhibited an excellent performance as a position guide mark
in dark surroundings. Further, the substrate (2) had an
excellent decorativeness as a deep yellow plate, was beautiful
even in the daytime and could be used also as a braille block for
a blind peraon.
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In a test according to JIS K-7112, the apecific gravity was
2.30. Further, the water absorption was 0.14$. With respect to
the properties in the protrusions (3) in a region where the
substrate (2) and the protrusions (3) were inteqrated, the
hardness, the abrasion resistance and the like were excellent as
shown in Table 1.
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Table 1
item Results Test conditions
Sending 63.55 kgf cm aaaordinQ to JI8 A-5209
strength
Compression 1380 kgf/cn Crosshead speed 0.5 mm/min
strength Load call 2 tons
Impact 4,57 kgf=cm/am2 Pendulum impact test
strength
Hardness 1020 kgf/mn Vickers hardness according to
JIS Z-2244
Abrasion 0.01 g J2S A-5209 sand dropping-type
rasistance abrasion test
Further, no abnormality was observed even in tests for an
acid resistance and an alkali resistance by the dipping in a 3*
hydrochloric acid aqueous solution for 8 hours and the dipping
in a 3-t sodium hydroxide aqueous solution for 8 hours.
Example 2
The molding was conducted in the same manner as in Example
1, using a mixture (6) for resin molding having the following
formulation.
Silica rock of from 10 to 50 mesh in which 50% by weight
a surface layer bakod with a strontium
aluminate luminescent material at
approximately 1,000 C was formed to a
thickness of approximately 30 (,tm
Silica rock powder having an average 20% by weight
particle diameter of 250 mesh
Powder of a strontium alesninate 20% by weight
luminescent material=having an average
particle diameter of 220 mesh
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Methyl mathacrylate (KIA) (containing 10% by weight
0.2$ by weight of a peroxide-type curing
agent)
. Th protrusions (3) were polished using a diamond grindstone
and a silicon carbide magnosia grindstone. Further, the resin
portion alone in the surface portion was removed at a water jet
pressure of 1, 200 kg/cm2 (nozzle diameter 0. 8 mm, a jat distance
35 men).
The resulting artificial stone had a depth and a non-slip
property in the daytime, and could be seen in the overall thickness
direction at night for a long period of time because of the
luminescence.
It could be used as a lumi.nous guide mark building material
in urgent power failure and thus as an effective artificial stone.
Example 3
The molding was conducted in the same manner as in Example
1, using a mixture (6) for resin molding having the following
formulation.
Silica rock of from 10 to 60 mesh 60* by weight
Aluminum hydroxide powder having an 22'b by weight
average particle diameter of 220 mesh
Strontium aluminate luminescent 10-t by weight
material havinq an average particle
diameter of 200 mesh
M~thyl methacrylate (A!MM (containing 8% by weight
0.15'b of a peroxide-type curing agent)
Likewise, a molded product which was excellent in physical
properties and a luminousness waa obtained.
Example 4
An artificial stone molded product having a thickness of
16 nsn in which embedded, grooves (4) having a depth of 4 rRn were
light-em.itting portions was obtained by the process in Figure 4,
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using the mixtures (6), (7) for resin molding in Exairrple 1.
The surface was polished by means of a diamond grindstone.
A molded product which was excellent in physical properties
and a luminousness was obtained.
INDUSTRIAL APPLICABILITY
As stated above, the present invention provides a high-
density artificial stone which was excella.nt in light properties
such as a luminousness and the like, which had a deep, glazed,
excellent tone of color, which was free from problems such as
delamination, dropping, abrasion and the like of light-emitting
portions and which had good physical properties. Sesides, the
production of such an excellAnt product is.realized at far lower
costs than the ordinary product.
