Note: Descriptions are shown in the official language in which they were submitted.
CA 02257425 1998-12-03
ARTIFiCIAL STONE
TaCa'IJICAL FIELD
The present invention relates to an artifioial stone. More
specifically, the present invention relates to a novel improved
higis-denaity artificial stone which has a granite-like or
marble-like excellent texture and excellent properties such as a
good surfaco hardness, a good surface abrasion resistance and the
like, which is light-weight and has a high hardness and a high
strength, and which can easily be adjusted to a desired thickness
at a low cost, and it is to provide an artiticial stone which is
useful as a wall material, a floormaterial, other buildingmat.ria.ls,
materials for construction, a stone pillar or the like.
SACY{6AOLJlr'D ART
It has been already known so far that a natural stone is
pulverized to an appropriate size, and mixed with calcium carbonate
and a resin, and then cured to form an artificial stone. That is,
it has been stated that a starting stone powder, a resin and the
li;ce are mixed under reduced pressure, and the mixture is poured
into a mold, withdrawn therefrom and cut.
Further, it has been also known that when an artificial stone
is produced using a powder of a natural stone and a synthetic resin,
it is required that the starting materials are used at a
predetermined mixing ratio and these are thoroughly pressurized
after they are put into a mold.
However, artificial stones obtained by these conventional
methods involve a problem that the color and the deep feeling are
not necessarily satisfactory even if using the natural stone powder.
The conventional artificial stone had a defect that the color
tone of the surface always becomes dull. Thus, in the past, it was
quite difficult to realize a transparent, deep and massy
granite-like or marble-like surface.
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This is presumably because characteristics of light
reflection or absorption on a surface of an artificial stone vary
greatly depending on the composition and the size and the formulation
of the artificial stone powder, but such a standpoint has not been
heretofore studied so much.
And the composition of the artificial stone greatly influences
a moldability. There are problems that a fluidity for molding in
a mold is lost depending on a size or a ratio of a natural stone
powder to be incorporated into an artificial stone, a ratio of a
binder resin or the like and bubbles remain inside a molded product,
notably impairing qualities and a strength of a product artificial
stone.
It is also considered that an amount of a resin component is
increased to improve a fluidity and prevent occurrence of bubbles.
Meanwhile, that an amount of a resin component is increased
to prevent occurrence of bubbles and secure a fluidity for feeding
into a mold helps provide a fluidity and prevent occurrence of
bubbles, but has an adverse affect on qualities of a resulting
artificial stone.
The use of the resin component in a large amount leads to
production of a resinous artificial stone product, and the resulting
product is nothing more than one in which an artificial stone powder
is present in a resin. Further, in view of properties, the product
is closer to the starting resin than to the starting stone.
Accordingly, although the resulting stone is called an artificial
stone, the resulting product is merely a resin product that looks
like a stone.
Then, the inventors of the present application have provided
a composition in which an inorganic material component comprises
a fine powder component having a larger particle diameter and a
finely divided component having a smaller particle diameter and a
mixing ratio of a resin is approximately 10% by weight or less
regarding such a novel artificial stone that when a powder of a
natural stone or the like is used as a material upon solving such
defects of the conventional artificial stone, the resulting product
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is of a dense texture, has characteristics such as a transparent
color tone, a deep feeling and a tone of a natural stone such as
granite, marble or the like and is excellent in moldability so
that an optional shape such as a plate, a bar or the like can be
provided.
This artificial stone has attracted attention as a stone which
is excellent in the color tone and the characteristics.
However, in the later studies, a problem has remained that
when attempts are made to provide this new artificial stone
composition having a thickness, the costs are increased in the
formulation of the inorganic material component and the production.
Further, problems have been left that the molded product is made
to have more improved properties or designing.
DISCLOSURE OF INVENTION
Under the above-mentioned circumstances, the present
invention has been made. In order to solve the above-mentioned
problems, the sum of a fine powder component of an inorganic material
having a size of from 5 to 70 mesh and a finely divided component
of an inorganic material of 100-mesh under is in an amount between
89% and 95% by weight based on the total amount of the product. It
provides an artificial stone characterized in that an artificial
stone mixture containing the inorganic material mixture component
comprising the fine powder component of the inorganic material and
the finely divided component of the inorganic material and 3%-11%-
by weight, based on the total amount, of a resin component, is
struck and combined with and integrated into a cured slab.
Further, the present invention provides an artificial stone
characterized in that a curable mixture is struck and integrated
into a cured slab which has been formed from the above-mentioned
artificial stone mixture.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a flow chart showing production of an artificial
stone of the present invention. Figure 2 is another flow chart.
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CA 02257425 1998-12-03
Figures 3 and 4 are partial perspective views showing the other
examples of production respectively.
BEST MODE FOR CARRING OVT THE INVENTION
The mode for carrying out the present invention is described
in more detail below.
First of all, the artificial stone mixture as a starting
material constituting tha artificial stone of the present invention
is roughly composed of three coaapononts. One theroof is a fine
powder component of an inorganic maaterial having a size of from 5
to 70 mesh as a main component. This is a fine powder component
of an appropriate inorganic material selected from minerals such
as silica rock, chrysolite, feidspar, pyroxono, mica and the like,
na-zural stones such as granite,matamorphite and the like,porcelain,
glxsses, metals and the like.
And alonq with this fine powder component, a finely divided
com;ponent having a size of 100 mesh-under is used. As this finnly
divided component, various natural or artificial finely divided
components are mentioned. For example, powders of calcium
carbonate, aluminum hydroxide and the like are easily obtainable
finely divided components.
Further, as a part of this finely divided component, 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, a boron compound, a bromine
compound or the like to impart a flame retardance may be blended.
A resin monomer component ia mentioned as a third component.
This resin monomer component is cured after struck and integrated,
and it can be selected from a wide variety of thermosetting
materials.
For example, this cosaponent constitutes an acrylic resin, a
methaorylic resin, an unsaturated polyester resin or the Iika.
Exam.ples thereof include monomers such as an acrylate aster, a
methacrylate ester and the like. Especially, from the standpoint
of a color tone, physicochemical properties and the like of the
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CA 02257425 1998-12-03
artificial stone after the curing, methyl methacrylate is typically
mentioned.
The fine powder component of a natural stone or the like acts
as a main factor of an appearance and physical properties of the
rosulting artificial stone. Especially when a part thereof is
exposed to the surface, it becomes a main factor of a color or a
pattern in the appearance along with the other coiaponentm.
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 tho fine powder component and is arranged to fill the space between
the particles, contributing toward providing properties such as a
hardness and a pliability of the resulting artificial stone. The
weight ratio of the fine powder component and the finely divided
component is preferably between 0.5:1 and 5:1.
Further, this resin component contributes to covering the fine
powdor component and the finely divided component of a natural stone
or the like which are componentsfora-ing the above-mentioned
structure to bind the whole body, and functions to impart a
resilience or a tensile strength to a product when an artificial
stone is completed.
In the present invention, the structural ratio of these
components is important. Especially important ia the structural
ratio of the resin component and the other components.
In the present invention, one of the characteristics is that
a high-density product having a dense texture can be provided. T1ne
"high-density" here referred to means that the fine powder component
and the finely divided component contained in the artificial stone
product are present at a high density. The degree thereof is that
the density is, for example, 2.2 g/csn' or more exceeding the range
included in the conventional artificial stone.
That is, the higher the structural ratio of the fine powder
component of a natural stone or the like as an aggregate component
in the product, the product is closer to the natural stone. However,
when the ratio is too high, a product is not solidified, and it cannot
CA 02257425 1998-12-03
be used as a co=nercial product. Further, physical properties of
the resulting product are poor, and it cannot endure ordinary use.
Further, when the ratio of the finely divided component is
too high, there occurs inconvenience that a product is not solidified.
Besides, the resulting product is not glazed, and it can hardly be
said as a stone.
Accordingly, the ratio ef the fine powd.r component or the
fincwly divided component is liznited. That is, the woight ratio has
to be 89% or more, pret'orably 90% or more. When it exceeds 95%,
thte product becomes brittle, and is hard to use. When it is lass
than 89%, the product is too soft to provide qualities as a stone,
and it is usod in the same range aas a resin plate.
This means that the component other than the fine powder
co.r~,onent and the finely divided component of a natural stone and
the like, namely, the resin component should not be present in the
product in an amount exceeding 11$ by weight.
When the amount of the resin component exceeds 11%, the product
is Iike plastics, and it is only seemingly an artiticial stone.
Further, when the amount of the resin component is excessively
decreased, a product comes to have an appearance close to a natural
color, but it becomes brittle and is unsuitable for actual use. From
this standpoint, the amount of the resin component is more preferably
between 3 and 10% by weight.
And in the artificial stone mixture of the present invontion,
it is one of the characteristics that a part or the whole of the
above-mentioned fine powder component of the inorganic material is
transparent particles and the particles or the small mass is
previously coated Mith an inorganic or organic material.
Such a coating of the transparent fine powder component is
conducted by coating the surface of the transparent fine powder
con, ponent with a resin and curing the same, or by baking an inorganic
material such as a water glass, a glazing agent for porcelain or
the like and coating the same thereon. In either case, a coating
with a thickness of from several micrometers to several t.ns of
reticrometers, for eXample, from 5 to 50 m, more preferably from 20
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CA 02257425 1998-12-03
to 30 pm is applied to the surfaces of the particles of the
tra.nsparent fine powder component. More specifically, an inorganic
matorial coating can be applied by, for example, heating a
composition of an acrylic resin, a methacrylic r.sin, an unsaturated
polyester resin or the like at from 150 to 300 C or irradiating the
same with light to coat the resin composition on the surfaces of
the particles of the fine powder component and cure the same, or
conducting the baking at a high temperature of from 800 to 1,100 c
using a water glass, a glazing agent or the like.
These coatings much improve the affinity for -the overall
structure of the fine powder component acting as an aggregate of
an artificial stone. Flsrthor, the mixing of the fine powder
component with the resin component increases a strength and gives
a good surface hardness.
It is further important that since the above-mentioned
transparent natural stone or the like is used as the fine powder
coa,ponent and the above-mentioned hard coating i9 applied to the
surface tharaof, this coated layer is partially broken by polishing
the surface of the artificiil stone product. Then, the surface
structure botwoan the particles of the partially exposed
transparent fine powder componant of the inorganio material and tho
surrounding coated layer comes to have a peculiar effect by light
roeloction.
That is, light is entered into tho transparant fine powder
aoasponent, reflected on the surrounding coated layer, permeated
again through the transparent tine powder component, and reflected.
Such a phenomenon of permeation and reflection is substantially
diFferant from ordinary reflection on a surface of an artificial
stone alone, and gives a peculiar deep feeling to the artificial
stone product of the present invention. A massy,deap,high-quality, enarbl -
like artificial stone is obtained.
The ratio of the transparent fine particle component having
the coated layer as mentioned above can be generally between 10 and
100'k based on the total aatount of the fine powder component of the
inorganic material contained in the coASposition.
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In the present invention, it ie necessary that the fine powder
cor.sponent of the inorganic material has the specific size as noted
above. That is, the fine powder cocinnonent of the inorganic material
has a size of from 5 to 70 mesh as awwntioned above. It is advisable
to use the same size except in special cases . W'hen an upper or lower
portion is colored dark using tha colored and colorless materials,
it is considered that the size of fine particles is changed depending
on the colored or colorless condition. However, fina part3cles
which are extremely different in the size shall not be used in large
atnounts because they deteriorate the atrongth of the product.
Meanwhile, the size of particles of the finely divided
component is 100 rnesh-under as noted above. The particles of the
finely divided component have to be fully incorporated between the
particles of the fine powder component. Accordingly, particles
having a size close to that of the particles of the tine powder
consponent are undesirable. More specifically, the size is
proZerably between 150 and 250 mesh.
And what is important in the artificial stone of the present
invention is that the artificial stone mixture is preferably
dispersed uniformly in any portions of the cured portion after the
at=riking except in apecial cases.
And it is advisable to polish the outer surface of the cured
portion. That is, it is advisable that the partially broken fine
powder component of the coated layer is exposed to at least a part
of the surface as mentioned above.
The polishing is a practically convenient method for exposing
to the surface a dense texture provided by the deep, high-density
artificial stone of the present invention. It is of course possible
that a part of a surface of a product is polished to expose a fine
powder component and a difference between this portion and the other
portion of the same surface is used as a pattern.
=n the case of obtaining an artificial atone, it is an iamportant
subject what color or dasign a targeted natural stone has. Granite
or marble is often targeted because a product from a natural stone
is hard to obtain and the color and the glaze are beautiful. In
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CA 02257425 1998-12-03
th:is instance, the color and the glaze are important subjects in
determining the value of granite or marble. Natural granite or
matble has a vide variety of colors, namely, from an exactly black
color to a white color or to a red color, and even one color is
di4"Zarent in color tone.
Usually, when various artificial stones are colored, for
example, when a black one is obtained, only a black powder of a
natural stone or the like can be used. aowever, when a stone of
a noutzal color is obtained, a r*producibility is at issue. Further,
even if a color was applied, it rvas digficult to give a glaze peculiar
to marble.
For example, even when a color was applied using a dye or a
pigment, it was difficult before to give a glaze or depth.
On the other hand, in the present invention, a transparent
component is used as a fine powder component. For example, when
a product having a granite-like or marble-like glaze is provided,
a fine powder obtained by pulverizing a quartz-type natural stone
can be used as the fine powder comcponent.
slnce a starting material of the fine powder obtained by
pulverizing the quartz-type natura], stone is a quartz type, the
surfcace has the peculiar smooth portion. Further, it is colorless
and transparent in many cases. When it is colored, the color tone
is not strong. When it is not transparent, a transparency somewhat
remains in many cases.
When this starting material is used, the color of the cured
portion which has been struck and cured can be controlled by the
color tone of the coated layer in tne fine powder component and the
resin component, and it can be deeply colored and glazed by the
presence of the transparent quartz-type fine powder component.
ror example, a baked layer of a water glass having a white
pigment or a cured layer of a polyester-type unsaturated resin is
provided as a coated layer. In this case, when a polyester-type
unsaturated resin is used as a resin coraponent, a color of a resin
is generally a slightly yellowish white color, and the resulting
product has then a glazed milk-white color, making it possible to
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CA 02257425 1998-12-03
provida a color tone aimilar to that: o!' natural milk-white msrble.
The coated layer is made to contain a coloring material such
as a pigment, a dye or the like, and further an inorgariic pigment
such as titanium dioxide, zirconium silicate, manganese dioxide,
iron oxide or cobalt oxide, an organic pigment such as an azo
pignnent or a phthalocyanine pigment, or various dyes are added to
a resin component, making it possible to give a uniform color and
a deep, glazed peculiar color tor.e.
Incidentally, in the artificial stone composition of the
present invention, it is nlso possible to color a product by mixing
a colored particulate component having approximately the same size
as the fine powder component, as a color component.
In any case, the color reproducibility can be secured quite
easily compared to the conventional artificial stone, and a stone
which is excellent in depth and a glaze without discoloration is
obL= ained .
Further, it is especially effective that a glazing agent for
coloring a porcelain or the like is coated on a powder of a natural
transparent fine powder coatponent, and the coatad material is baked
to give a powdor having a desired color which is used as a fine powder
component. When using this method, not only can a stable color be
provided, but also it can be selected from a wide range.
When a component which is obtainedbypulverizing a quartz-type
natural stone and which is the same as the fine powder component
is used, coated with a glazing agent and baked, a reproducibility
of a color such as black or red is provided without any anxiety.
With respect to a color to be reproduced, not only the color but
also a glaze or a color tone is completely reproduced. Accordingly,
the color becomes one which cannot be given by a usual coloring
me thod .
At any rate, the fine powder component in which the coated
layer is fosiaed by this baking is used at a ratio of from 10 to 100'k
based on the total amount of the fine powder component.
Further, in relation to tho color tone, a short fiber component
may be incorporated for reinforcing the texture of tha molded product.
CA 02257425 1998-12-03
Exa.-nples thereof include glass fibers, ceramic fibers, metallic
fibers, resin fibers and the like. Of theae, glass fibers are
preferable.
With respect to the short fibers, those having a diameter of
from 10 to 100 }Am and a length vf from 1 to 10 mm are used at a ratio
of from 1 to 10$ by weight of the fine powder component.
First, a cured slab into which to strike and integrate the
above-mentioned artificial stone mixture is here described. This
cured slab is one which has been cured, and the above-mentioned
artificial stone mixture is struck and integrated thereinto upon
placing or not placing the slab in a mold.
For example, Figure 1 illustrates a method in which the
above-mentioned artificial stone mixture (3) is injected on the
a;Dove-mentioned cured slab (2) put on a mold (1), and cured by
pressing the same using a press (4) to integrate the cured portion
(5) into the cured slab (2) . Further, Figure 2 illustrates a method
in which the artificial stone mixture (3) is injected into the mold
(1) , and the cured slab (2) is placed thereon and likewise pressed
using the press (4).
Of course, the method is not limited to the examples shown
in Figures 1 and 2. As shown in Figure 3, it is also possible that
the artificial atone mixture (3) ia struck into a predetermined notch
or groove formed in the cured slab (2) as if it were embedded therein
and the cured portion (5) is integrated thereinto. As shown in
Figure 4, it is further possible that the artificial stone eaixture
(3) is struck into the cured slab (2) having a metal body (6) of
a predetermined shape or the like and the cured portion (5) ia
integrated thereinto. Thus, various modas are possible.
In any case, the cured slab (2) may include various
compositions such as a cemar-t type, a resin type, an inorganic cement
type and the like. Eiowever, from the standpoint of the integration
a: tefi the moldir-yT with the istit'icial stone mixCure, namely, the
adhesion, it ia preferable that this cured slab contains a resin
couponent and it contains a resin of the same quality as the
artificial stone mi.xture as much am pos9ible.
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Nowever, an inorganic a-aYerial component, a color tone and
the like of the cured slab are selected as required, and it can be
composed of a less costly industrial waste such as a blast furnace
slab, a glass or the like.
Accordingly, an artificial stone having a certain thickness
can be formed such that a less costly cured slab is used as a lining
material, its thickness is increased, and only the surface layer
is formed by striking the above-mentioned artificial stone mixture
formed of the costly material.
Naturally, it is also possibla that the cured slab is formed
wit'ti the same composition as tl-e artificisl stone mixture, and the
artificial stone mixture is struck and integrated thereinto.
Urnlike the adhesion of the cured bodies to oach other, the
integration 5.s realized upon providing a great strength without
using an adhosive.
For example, the resin may be various thermosetting resins
such as a methacrylic resin, an unsaturated polyester resin and the
Ii.kqa. In these resins, a curad slab can be formed by using 60 to
90% 17y weight, based on the total amount, of a blast furnace slab,
a pulverized glass, various inorganic slabs obtained from an
incinerator or the like as a substitute component of an aggregate
or the like. These can also be reused. The thickness of the cured
slab relative to the thickness of the product formed by striking
and integration varies depending on the use. For example, it a.ay
occupy approximately 95'b of the overall plate thickness. Flirther,
the cured slab may be formed with the same composition as the
above-mentioned artificial stone mixture in the preaent invention
as described earlier.
Still further, in the present invention, it goes without saying
that a sandwich structure may be provided by striking the other
artificial stone mixture (3) on the cured slab (2) in Figure 2.
In any of the above-mentioned cases, the surface formed from
the artificial stone mixture struck and cured is arranged to be a
surface of a product.
Furthermore, in this description, an artificial stone
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CA 02257425 1998-12-03
obtained by previously forming a cured slab from the above-mentioned
artificial stone mixture and striking and integrating a curable
mixture corresponding to the cured slab containing the blast furnace
slab or the like into this cured slab is also intended in the
invention, and the present invention provides this artificial
stone.
In this structure, the artificial stone of the present
invention can also be made to have a lusninousness or a fluorescence.
This can be conduct=d by blending the above-mentioned artificial
stone mixture forming at lea9t the surface of the artificial stone
with a luminous or fluorescent component.
It is a practical characteristic feature that at least a part
of the fine powder component as a structural component is baked or
coated at room temperature with the above-mentioned luminous
material or fluorescent material.
In the aggregate of the transparent inorganic material,
especially, the baked coating of the fine powder component, a coating
having a thickness of from several micrometers to several tens of
micrometers, for example, from 5 to 50 pm, preferably from 20 to
40 pm is applied to the surface of tha particle in the transparent
fine powder. .cousponent. More specifically, the coating is applied
by the baking at a high temperatura of from 120 to 1,200 C.
The fluorescent material to be baked can inalude varioua
fluorescent mat:rials which have a luasinescence or which .:oit light
through ultraviolet-light irradiation,such as strontium aluminata,
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
exaarple, the above-=nentioned fine powder component with a
diaperaion or a paste having dispersed therein a fine powder of a
luminescent material such as strontium aluminate or the like and
drying the mixture.
The room-temperature coating is conducted also using a
transparent stickymaterial (binder) as the dispersion or the paste.
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In this construction, light irradiated froln outside reaches
the internal coating material baked. Fw.rther, when a methacrylic
resin (MMA resin) having an nxcollent transparency is used as a resin
coraponent, light is entered into the overall thickness direction
of tYhe artificial stone.
Consequently, the incidant light is permeatQd into the inside,
and light is emitted from inside. That is, the light absorption
layor and the light-emitting layer become thick. For this reason,
light can be storad for a short pariod of time, and a light-emitting
afZiciancy is also increased.
since only the surgace of the fine powder component is coated,
the luminous or fluorescent material is used in a small amount.
And in the present invention, a luminous or fluorescent
material of 100 mesh-under having a luminescence or a light-emitting
property accompanied by ultraviolet absorption may directly be
contained as at least a part of the=finely divided component.
Typical exansples thereof include a strontium aluminate luminescent
cnateriai, zinc sulfide and the like. These various materials are
ustaci in the present invention.
The size of the finely divided component is much smaller than
the 100 a-osh level in comparison to the fine powder componant. The
finely divided component enters between the individual particles
of the fine powder component and is arranged to fill the space between
the particles, contributing toward providing properties such as a
harcinoss and a pliability of the resulting artificial stone.
And the above-mentioned luminous or fluorescent component
plays the same roll as the finely divided componont, contributing
toward imparting a light function such as a luminousness or a
fluorescence to the artiticlal stone.
With respect to the above-mentioned inorganic material
component, the size and the ratio are important.
The relationship of. the weight (Wl) of the above-mantionad fine
powder component of the inorganic material, the weight (W2) of the
fineiy divided component of the inorganic material and the weight
(WO of the luminous or fluorescont corogponent is prefarably as
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CA 02257425 2006-05-12
follows.
Wl (Wz + W3) = 1:2 to 5:1
W2 W3 = 1:2 to 10:1
With respect to W1 (WZ + W3), it is preferably between 1:1
and 4:1. With respect to W2 . W3, it is preferably between 1:1 and
5:1.
And in the fine powder component of the inorganic material,
it is advisable that the ratio of the fine powder component= of the
transparent inorganic material therein has preferably the following
relationship.
(0.3 to 1.0)W1
The above-mentioned facts are 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.
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 powder of a transparent inorganic
material, and from 30 to 100% by weight of the finely divided
component of the inorganic material is a finely divided component
of a transparent inorganic material, and
2) a luminous or fluorescent component of 100 mesh-under is
mixed at the above-mentioned specific ratio. 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 as follows. The use of the fine powder component
of the transparent inorganic material and further the finely divided
component as a transparent aggregate helps permeate light
irradiated from outside into the inside of the artificial stone to
efficiently absorb the light energy in the luminous or fluorescent
component, and the fluorescent layer having dispersed therein the
luminous or fluorescent component formed of the luminescent
material or the like is secured as a great thickness including the
inside of the artificial stone, so that a high luminosity can be
CA 02257425 1998-12-03
maintained for a long period of time. In the light emiasion, the
fi:-e powder component of the transparent inorganic material comes
to have a high luminosity because it is good in a light transmission.
A process for producing the artificial stone of the present
invention by striking and integrating the artificial stone mixture
into the cured slab is realized by conducting the compression molding
through, for example, pressing at a surface pressure of from 5 to
100 kgf/cm2 in the above-mentioned press-molding. And .in this
molding, it is preferable to conduct heating at a temperature of
Zrom approximately 90 to 140 c for from 5 to 20 minutes in the
compression.
Further, in the compression molding with heating, vibration
is applied to a mold along with a pressure, making it possible to
improve a fluidity of the above-mentioned mixing material in the
mold.
This process using such a compression molding exhibits a
mas+s-production effect as a process for producing a product with
a relatively simple shape, such as a flat molded product, and there
is almost no loss of a material, so that the process is economically
excellent too.
And in the present invention, the cured surface of the
arCi2icial stone mixture after the molding may be polished or
rouyhened to expose the finely divided component to the surface.
As this roughening method, a method of selectively removing
the resin component is employed. That is, it is effective, .for
example, that after the product is removed from the mold, hig'cs-
prwsisure water is jetted on the surface of the molded product to
conduct the texture treatment.
Since this treatment varies depending on various conditions
such as a thickness, a distance from a nozzle, a treatment mode and
the like, it is not lirnitative. Sowever, usually, in the case of
a thiakness of from 2 to 20 asn, a water paessure of from 50 to 1, 400
kg/cm2 can be applied from a height of a nozzle of from 2 to 50 esa.
This water pressure is far lower than when a natural stone is used.
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CA 02257425 1998-12-03
rl L17-' I 0'lTl 1 r-1 U/ -w~111 T -t G/ neam J=-
That is, this is because the high-quality treatment can be
conducted more easily by the presence of a resin component.
A nozzle for jetting high-pressure water or its system is not
particularly 1lmited. Various types are employable.
The surface is flattened or roughened using the water jet 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 water 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 coraponent and partially
resrtove the same.
In this case, the organic solvent corresponding to the resin
component may be selected. Exainples thereof include halogenated
hydrocarbons such as methylene chloride and chloroform, carboxylic
acida and esters thereof such ss acetic anhydrxde, ethyl acetate
and butyl acs+tate, acetone, tetrahydrofuran, DMF and D[=iBO.
The molded product 3s dipped in these organic solvants 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 surt'ace is roughened by the above-mentioned various means,
and the texture is treated. Then, the resulting surface is polished
to partially break the coated layer of the fine powder component
on the surface and expose the coated layer and the particles of the
fine powder component to the surface of the product as a section.
Then, the peculiar deep, glazed surface quality is realized.
A etwa-ns for surface polishing is not particularly limited.
It can be conducted using a tool such as a grind:tone, 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.
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CA 02257425 1998-12-03
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 oy-ide which
have mainly a scratching action are used as required.
Of course, after such a polishing is applied, the surface may
further be roughened to form raisings and depressions.
In this manner, the artificial stone having an excellent
textura, excellent qualities and l3ght-emitting properties is
producod.
The present invention is illustrated by referring to tha
foilowing Examples. Naturally, the present invention is not
limited to these Examples.
EXAPlPLE
Example I
A composition comprising 608 by weight of a blast furnace slag,
30* by weight of a pulverized natural stone having an average
pazticle diamoter of 10 rnesh and 10iF by weight of methyl mothacrylate
(ccantaining a curing agent) was compression-molded in a mold. Then
a cured slab having a thickness of 12 mm was obtained.
This was placed into a mold as shown in Figure 1.
A natural silica rock having a particle diameter of from 10
to 25 mash in which a baked surface layer with a thickness of
approximately 30 }ua had been formed at approximately 1, 000 C using
a white gla2ing agent was used in an amount of 50% by weight based
on the total fine powder component. The fine powder component and
alumYnum hydroxide of 230 mesh at the weiqht ratio of 2:1 were
uniformly mixed in amounts of 9041 by weight based on the total
amount of the composition with 94 by weight of a mothyl mothacrylata
monomer and 14 by weight of a curing agent to form a mortar-like
artificial stone mixture.
This anl.atuxe was charqsd on a cured slab in a mold, and
compresoed at a temperature og 110 C and a surface pressure ot 30
kgf/am' for 15 minutes to form a plate having a thickness of
approximately 15 mm.
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Subsequer-tly, the surfsce cured from the artificial stone
mixture was polished using a corundum polishing agent.
Consequently, in the fine powder component having the baked coated
layer, the partial sections of the baked layer and the fine powder
component were ampoased to the surface.
The resulting artificial stone had a deep milk-whito color
and a glaze of marble, and was free from bubblea in the inside or
the surface. Thus, th= coaeposition was uniform.
The adhasion between the cured slab and the cured portion of
the artificial stone mixture was satisfactory in the strength.
In a teat according to JIS K-7112, the specific gravity was
2.02 Further, the water absorption was 0.1016. The other
prcperties are as shown in Table 1 below.
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Table 1
Item Results Test conditions
Sending 30.28 kgf/cm according to JIS A5209
strength
Cornpression 1180 kgf/cza Crosshead speed 0.5 mm/min
strongth Load cell 2 tons
Iarpact 3.78 kgf=cm/cra2 Pendulum impact test
s trong-th
iiardrness 976 kgf/mm Vickers hardness according to
JIS Z-2244
2.l.near
aApansion 0.68 (x 10"5R) TMA (30 to 100 C)
coefficient
P,brasion JIS A-5209 sand dropping-type
resistance 0.02 g abrasion test
When the resulting product was used as a wall plate of a
building, a wall having a deep, beautiful color tone of marble could
be obtained. The production cost as an artificial stone product
couid be reduced to approximately 1/30 that of the plate 15 mat thick
which was obtained without using the above-mentioned cured slab.
c.xar;hple 2
A plate was obtained aa in Exaaqple 1 using tha following
artificial stone mixture.
That is, a natural silica rock having a ps-rticle diameter of
f rom 10 to 25 mesh in which a baked surface layar with a thiakness
of approximately 30 ta had been foraed at approximately 1, 000 C using
a strontium alminata luminescent material was used in an amount of
50S by weight baaed on the total =ine powder component. The rine
powder component and calcium carbonate having an average particle
diameter of 230 mesh at a weight ratio of 2:1 were uniformly mixed
in azaounts of 89% by weight based on the total amount of the
composition with 11% by weight of a mathyl methacrylate (DMA) and
1.5% by weight, based on the MN3A weight, of a curing agent to form
a mortar-like artificial stone mixture.
CA 02257425 1998-12-03
This mixtura was eharged, and molded into a plate having a
thickness of approximately 15 tmm.
Subsequently, the surface was polished using a diamond
grindstone and a silicon carbideemagnesia grindstone Consequently,
in the fine powder component having the baked coated layer, the
partial sections of the baked layer and the fine powder component
.+ere exposed to the surface.
The resulting artificial stone exhibited light-
storing/light-emitting properties such as a luminousness in the
overall thickness direction, had a deep milk-rrhite color and a glaze
of marble evan in the daytime, and was free from bubbles in the inside
or the surf ace . Thus, the composi ti on was unif orm .
In a test according to JIS K-7112, the speciric gravity was
2.02. Further, the water absorption was 0.10%. The other
properties are as shown in Table 2 below.
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Table 2
Item Results Test conditions
Bending 30.15 kgf/cm according to JIS A5209
sL-rength
Camprossion 1058 kgf/ain Croashaad speed 0.5 mm/min
strength Load cell 2 tons
Iarsact 3.81 kgf=cm/cie Pendulum impact test
a trength
Eiardness 985 kgf/mm Vickers hardness according to
JIS z-22aa
Z.i n'ar
ex-pansion 0.69 (x 10-5K) TMA (30 to 100 C)
coefficient
P,t,rasion JIS A-5209 sand dropping-type
rasistance 0.03 g abrasion test
Further, no abnormality was observed even in tests for an acid
rasiatance and an alkali resistance by the dipping in a 3%
hycirochloric acid aqueous solution for 8 hours and the dipping in
a 3* sodium hydroxide aqueous solution for 8 hours.
When the resulting product was used as a wall plate of a
building, a wall having a deep, beautiful color tona of marble could
be obtained.
Example 3
A transparent glass having a particle diamater of from S to
50 mash in which a baked surtace layer had been formed pith a
thickness of approximataly 40 pm at 700 C using a atrontium
aZuminate-type luminascent material was used in an aumount of 40%
by weight baaad on the total fine powder component. The fine powder
component and a natural silica rock powder having an average particle
diameter of 250 mesh at the weight ratio of 2:1 were uniformly m.irod
ln amounts o= 870 based on the total amount of the composition with
13-t by weight of inethyl methacrylate (containing 2.0% by weight of
a peroxide-type curing agent). Thetaixture in a necessary amount
was charged into a mold such that a thickness after the curing became
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3 = as shown in Fig. 2.
Subsequently, a cured slab 10 ncn thick which had been cured
was placad on this artificial stone mixture. This cured slab was
formed from 30'b by weight of a blast furnace slag, 20$ by weight
of a glass powder, 30% by weight of a pulverized natural stone and
20% by weight of inethyl methacrylate (containing a curing agent)
through compression molding.
After the cured slab was placed thereon, molding by pressing
and heating was conducted to form a plate having a thickness of 13
a~n.
Then, the surface was polished using a diamond grindstone and
a silicon carbide magnesia grindstone. Further, only the resin
portiori on the surface was removed at a water jet pressure of 1, 100
kg/czn' (nozzle diameter 0.75 irae, a jet distance 40 aen) .
The resulting artificial stone had 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
lumiAascence.
It could be used as a luminous guide mark building material
in urgent power failure and thus as an effective artificial stone.
The adhesion strength of the adhered portion between the cured
portion from the artificial stone mixture and the cured slab was
great, and not problematic practically.
Example 4
The following components were uniformly mixod to form a mortar.
(% by weight)
Transparent natural silica rock
(10 to 70 mesh) : 50
Aluminum oxide
(average particle diameter 220 mesh) : 10
Transparent silica rock powder
(average particle diameter 200 mesh) _ 10
Strontium aluminate luminascent material
(average particle diameter 200 mesh) : 20
Mothyl methacrylato (MMA) 10
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(containing a 0.15V peroxide-type 14-M curing agent)
The resulting mixture was charged into a mold, and molded into
a plate having a thickness of 3 mm.
This plate was placed in the mold, and a curable mixture having
the following composition was poured thereon.
Blast furnace slag 30% by weight
Glass powder 10% by weight
Pulverized natural stone 40% by weight
Mothyl mothacrylata 20% by weight
(containing a curing agent)
After the pouring, comprassion was conducted at a temperature
of 110 C and a surface pressure of 40 kgf/crO for 20 minutes.
A plate artificial stone having a thickness of 14 mm was
obtai.ned through this compression.
Then, the surface of this artificial stone was polished using
a cliamond grindstone and a silicon carbide=magnQsia grindstone to
aeijju:6t the thickness to 10 mm.
The reaulting artificiai stone exhibited light-
storing/light-emitting properties such as a luminousness in the
overall thickness direction, had a deep milk-white color and a glaze
of marble even in the daytima, and was free frombubbles in the inside
or the surfaca. Thus, the composition was uniform.
In a test according to JIS K-7112, the specific gravity was
1.98. Further, the water absorption was 0.10%o- The other
properties are aa shown in Table 3 below.
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Table 3
Item Results Test conditions
Hending 29.97 kgf/cm according to JIS A5209
s trength
Compression 1185 kgf/cm Croaahead speed 0.5 mm/min
strength Load cell 2 tons
Impact 4.08 kgfecm/cm= pendulum impact test
strength
Hardness 997 kgf/mm Vickers hardness according to
JIS 2-2244
Linear
expansion 0.69 (x 10-'K) THA (30 to 100 C)
ccwfgicient
Abrasion JIS A-5209 sand dropping-type
resistance 0.02 g abrasion test
Further, no abnormality was observed even in tests for an acid
resistance and an alkali resistance by the dipping in a 3'k
hydrochloric acid aqueous solution for 8 hours and the dipping in
a 3% sodium hydroxide aqueous solution for 8 hours.
Whan the resulting product was used as a wall plate of a
building, a vral.l having a deep, baautiful color tone of marble could
be obtained. Further, light stored from the sun in tho daytimab in
gine weather maintained its affect with the high luminosity at night
for a long period of time. A good quality was provided owing to
the light-waitting portions having a thiakneaa.
Example 5
In the formulation of Example 4, a ratio of a silica rock powder
was changed to 20%, a ratio of a strontium aluminate-type luminescent
material to 10%, a ratio of a natural silica rock to 62$ and a ratio
of mothyl methacrylate (MMA) to 804 respectively, and the components
were uniformly ml:ed. The mixture was molded into a plate having
a thickness of 14 mm.
Than, the surface was polished using a diamond grindstone and
a silicon carbide magnesia grindstone. Further, only the resin
CA 02257425 1998-12-03
portion on the surface was removed at a water jet pressure of 1,100
kg/cm2 (nozzle diameter 0.75 men, a jet distance 40 aan) .
The resulting artificial stona had depth and a non-slip
property in the daytime, and could be seen in the overall thickness
direction at night for a long pariod of ti.mft because of the
luminosc nae.
It could ba used as a luminous guide mark building material
in urgent power failure and thus as an affective artificial stone.
MDUSTRIAL APPLICAHZLZTY
Rs stated above, the present invention provides a high-density
artiPicial stone which has a deep, glazed excellent color tone that
has not been provIded so far as well as good characteristics at quite
low coats. The resulting product in of a uniform quality which has
not been found in a natural product. Besides, such an excellent
prociuct can be produced without using a special costly equipmant.
Especially, the artificial stone of the present invention is
suitable for providing a granite tone or a marble tone, and it can
be used in the same manner aa a natural stone. Further, a function
of a luminousness comes to be realized.
The product can be used in a rrall material, a floor material,
a pillar or the like as a deep, high-quality product in a wider range
t3nar, a natural product.
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