U.S. patent application number 14/066939 was filed with the patent office on 2014-05-01 for building board and method for producing the same.
This patent application is currently assigned to Nichiha Corporation. The applicant listed for this patent is Nichiha Corporation. Invention is credited to Toshio IMAI, Hiroaki YAMAMOTO.
Application Number | 20140120342 14/066939 |
Document ID | / |
Family ID | 49515188 |
Filed Date | 2014-05-01 |
United States Patent
Application |
20140120342 |
Kind Code |
A1 |
IMAI; Toshio ; et
al. |
May 1, 2014 |
BUILDING BOARD AND METHOD FOR PRODUCING THE SAME
Abstract
A building board includes a base material, an insulating coating
film for covering a surface of the base material, and a transparent
clear coating film for covering the insulating coating film. The
insulating coating film contains a coating film forming material,
organic hollow particles, and a water-soluble solvent. The method
for producing the building board includes a step of forming an
insulating coating film in which an insulating paint is applied to
a surface of the base material and then dried to form the
insulating coating film, and a step of forming a clear coating film
in which a clear paint is applied to a surface of the insulating
coating film and then dried to form the clear coating film. The
insulating paint contains a coating film forming material, organic
hollow particles, and a water-soluble solvent.
Inventors: |
IMAI; Toshio; (Nagoya-shi,
JP) ; YAMAMOTO; Hiroaki; (Nagoya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nichiha Corporation |
Nagoya-shi |
|
JP |
|
|
Assignee: |
Nichiha Corporation
Nagoya-shi
JP
|
Family ID: |
49515188 |
Appl. No.: |
14/066939 |
Filed: |
October 30, 2013 |
Current U.S.
Class: |
428/313.5 ;
427/379 |
Current CPC
Class: |
Y02W 30/97 20150501;
E04C 2/04 20130101; Y02W 30/91 20150501; C04B 41/71 20130101; C04B
41/52 20130101; Y10T 428/249972 20150401; E04F 13/0866 20130101;
C09D 7/65 20180101; E04B 1/806 20130101; C09D 5/00 20130101; C04B
41/009 20130101; C04B 41/009 20130101; C04B 18/26 20130101; C04B
28/02 20130101; C04B 41/009 20130101; C04B 28/02 20130101; C04B
38/00 20130101; C04B 41/009 20130101; C04B 20/0048 20130101; C04B
28/18 20130101; C04B 41/009 20130101; C04B 28/14 20130101; C04B
41/52 20130101; C04B 41/483 20130101; C04B 41/52 20130101; C04B
16/08 20130101; C04B 41/4961 20130101; C04B 41/52 20130101; C04B
20/004 20130101; C04B 41/4961 20130101; C04B 41/522 20130101; C04B
41/52 20130101; C04B 41/4961 20130101; C04B 41/52 20130101; C04B
41/5089 20130101 |
Class at
Publication: |
428/313.5 ;
427/379 |
International
Class: |
E04B 1/80 20060101
E04B001/80 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2012 |
JP |
2012-240115 |
Claims
1. A building board comprising: a base material; an insulating
coating film for covering a surface of the base material; and a
transparent clear coating film for covering the insulating coating
film, wherein the insulating coating film contains a coating film
forming material, organic hollow particles, and a water-soluble
solvent, the organic hollow particles have an average hollow ratio
of 80% or more and an average particle diameter of 5 to 50 .mu.m,
and the water-soluble solvent is at least one of a glycol-based
solvent and a glycol ether-based solvent.
2. The building board according to claim 1, wherein the organic
hollow particles comprise at least one of acrylonitrile,
methacrylonitrile, vinylidene chloride, acrylic ester, and
styrene.
3. The building board according to claim 1, wherein the insulating
coating film contains 0.01 to 5.0 parts by mass of the organic
hollow particles with respect to 100 parts by mass of solid content
thereof.
4. The building board according to claim 1, wherein the insulating
coating film has an average film thickness of 5 to 500 .mu.m.
5. The building board according to claim 1, wherein a transparent
hydrophilic coating film is formed as an outermost layer so as to
cover the clear coating film.
6. The building board according to claim 5, wherein the hydrophilic
coating film is constituted by at least one of silica, colloidal
silica, and fumed silica.
7. The building board according to claim 1, wherein the base
material is a ceramic siding board.
8. A method for producing a building board comprising a base
material, an insulating coating film for covering a surface of the
base material, and a clear coating film for covering the insulating
coating film, the method comprising: a step of forming an
insulating coating film in which an insulating paint is applied to
a surface of the base material and then dried to form the
insulating coating film; and a step of forming a clear coating film
in which a clear paint is applied to a surface of the insulating
coating film and then dried to form the clear coating film, wherein
a paint containing a coating film forming material, organic hollow
particles, and a water-soluble solvent whose boiling point is
higher than a temperature of the coating film when the coating film
is dried in the step of forming an insulating coating film and the
step of forming a clear coating film is used as the insulating
paint, the organic hollow particles have an average hollow ratio of
80% or more, and an average particle diameter of 5 to 50 .mu.m, and
the water-soluble solvent is at least one of a glycol-based solvent
and a glycol ether-based solvent.
9. The method for producing a building board according to claim 8,
wherein the temperature of the coating film is set to not more than
130.degree. C..degree. when the coating film is dried in the step
of forming an insulating coating film and the step of forming a
clear coating film.
10. The method for producing a building board according to claim 8,
wherein the organic hollow particles comprise at least one of
acrylonitrile, methacrylonitrile, vinylidene chloride, acrylic
ester, and styrene.
11. The method for producing a building board according to claim 8,
wherein the insulating paint contains 0.01 to 5.0 parts by mass of
the organic hollow particles with respect to 100 parts by mass of
solid content thereof.
12. The method for producing a building board according to claim 8,
further comprising a step of forming a hydrophilic coating film in
which a hydrophilic paint is applied to a surface of the clear
coating film and then dried to form a transparent hydrophilic
coating film as an outermost layer.
13. The method for producing a building board according to claim
12, wherein the hydrophilic paint is a solution in which at least
one of silica, colloidal silica, and fumed silica is dispersed.
14. The method for producing a building board according to claim 8,
wherein the base material is a ceramic siding.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a building board that is
used for exterior walls and the like of buildings, and a method for
producing the building board.
[0003] 2. Description of the Related Art
[0004] In recent years, there is a demand for improvement of
thermal insulation effect for building boards used for exterior
walls and roofs of buildings such as residential houses in view of
environmental problems such as energy conservation. To this end, it
has been considered that an insulating coating film is formed on
the surface of the building board.
[0005] For example, JP 2000-71389A proposed an insulating wall
material obtained by forming, on the surface of a base material, an
insulating coating film containing mixed and dispersed fine ceramic
particles having a thermal insulation effect in a coating film
forming material.
SUMMARY OF THE INVENTION
[0006] However, it was found from the results of experiments
conducted by the inventors that the actual thermal insulation
effect of the building board on which the insulating coating film
containing mixed and dispersed fine ceramic particles was formed as
described above was small (see the experiment described below). As
a result of intensive research conducted by the inventors, it was
found that one of the reasons was the fact that a hollow ratio of
fine ceramic particles tends to become low, and therefore a thermal
insulation effect is hard to be obtained.
[0007] Furthermore, superior weatherability is required so that
building boards are used for exterior walls, roofs, or the like of
buildings.
[0008] The present invention was made in view of these backgrounds,
and it is an object thereof to provide a building board that has
superior thermal insulation properties and weatherability, and a
method for producing the building board.
[0009] An aspect of the present invention is a building board
including a base material, an insulating coating film for covering
a surface of the base material, and a transparent clear coating
film for covering the insulating coating film, wherein the
insulating coating film contains a coating film forming material,
organic hollow particles, and a water-soluble solvent.
[0010] Another aspect of the present invention is a method for
producing a building board including a base material, an insulating
coating film for covering a surface of the base material, and a
clear coating film for covering the insulating coating film, and
the method includes a step of forming an insulating coating film in
which an insulating paint is applied to a surface of the base
material and then dried to form the insulating coating film, and a
step of forming a clear coating film in which a clear paint is
applied to a surface of the insulating coating film and then dried
to form the clear coating film, wherein a paint containing a
coating film forming material, organic hollow particles, and a
water-soluble solvent whose boiling point is higher than a
temperature of the coating film when the coating film is dried in
the step of forming an insulating coating film and the step of
forming a clear coating film is used as the insulating paint.
[0011] In the building board described above, the insulating
coating film includes organic hollow particles. Thereby, the
thermal insulation function is provided to the insulating coating
film. Since the organic hollow particles include an organic
material, the hollow ratio thereof tends to become high. That is,
since organic materials are flexible, the materials easily stretch
when hollow particles are formed, so that the hollow ratio thereof
is able to be high. Therefore, the thermal insulation effect of
organic hollow particles is large, and the thermal insulation
properties of the insulating coating film can be improved.
[0012] Since the insulating coating film contains a water-soluble
solvent, the homogeneous insulating coating film can be formed.
That is, mixing of organic hollow particles having the high thermal
insulation effect therein as described above may be considered to
cause a problem in that it is hard to uniformly transmit heat to
the entire coating when insulating paint is dried after being
applied to a base material. Accordingly, the water-soluble solvent
is contained in the insulating coating film, so that heat is easily
transmitted to the entire coating when the paint is dried.
Therefore, a homogeneous insulating coating film can be formed.
Thereby, a homogeneous thermal insulation effect can be obtained by
the insulating coating film all over the building board, and
therefore the thermal insulation properties of the building board
can be improved as a whole.
[0013] The building board includes a transparent clear coating film
for covering the insulating coating film. Thereby, the
weatherability of the building board can be improved. Moreover,
since the clear coating film is transparent, the clear coating film
neither stores heat nor inhibits the thermal insulation effect of
the insulating coating film. That is, the weatherability of the
building board can be improved without the thermal insulation
effect being inhibited by forming the clear coating film.
[0014] In the method for producing the building board, the
insulating paint used in the step of forming the insulating coating
film contains a coating film forming material, organic hollow
particles and a water-soluble solvent. Thereby, as described above,
the thermal insulation effect of the insulating coating film can be
improved to produce the building board having the superior thermal
insulation properties.
[0015] Note that the boiling point of the water-soluble solvent is
higher than the temperature of the coating film when the coating
film is dried in the step of forming the insulating coating film
and the step of forming the clear coating film. Therefore, even
after the coating film is dried in each step, the water-soluble
solvent remains sufficiently, and can contribute to the formation
of the homogeneous insulating coating film.
[0016] As described above, with the present invention, a building
board having superior thermal insulation properties and
weatherability, and a method for producing the building board can
be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic cross-sectional view of a building
board of Example 1.
[0018] FIG. 2 is a schematic cross-sectional view of a building
board of Example 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] In the method for producing the building board described
above, the temperature of the coating film refers to the
temperatures of the insulating coating film and the clear coating
film.
[0020] The water-soluble solvent includes at least one of a
glycol-based solvent and a glycol ether-based solvent, and can
effectively achieve the formation of the homogeneous insulating
coating film. That is, the glycol-based solvent and glycol
ether-based solvent have a high boiling point and tend to remain
until the end of the step of forming the insulating coating film.
Therefore, the glycol-based solvent and glycol ether-based solvent
may contribute to homogenization of the insulating coating
film.
[0021] It is preferable that the organic hollow particles include
at least one of acrylonitrile, methacrylonitrile, vinylidene
chloride, acrylic ester, and styrene. In this case, it is possible
to especially stably obtain the organic hollow particles in which
the hollow ratio is high.
[0022] The average hollow ratio of the organic hollow particles is
80% or more, and the insulating coating film can provide a
sufficient thermal insulation effect.
[0023] It is preferable that the average hollow ratio is 90% or
more. In this case, the insulating coating film can provide an even
better thermal insulation effect. Furthermore, a preferable upper
limit of the average hollow ratio varies due to various factors as
long as the hollow state of the organic hollow particles can be
maintained.
[0024] Note that the average hollow ratio is a value expressed as a
percentage by volume. The same applies hereinafter.
[0025] A transparent hydrophilic coating film may be formed as an
outermost layer so as to cover the clear coating film. In this
case, an appearance design of the building board can be maintained
for a long time. That is, the hydrophilic coating film described
above is formed as the outermost layer, so that, even if dirt is
attached to the surface of the building board, namely, the surface
of the hydrophilic coating film, water is absorbed into the
hydrophilic coating film, and the dirt runs down together with
water, by water being poured on the surface of the building board
or by rainwater falling thereon. Therefore, the appearance of the
building board can be maintained for a long time. Furthermore, dirt
attached to the surface of the building board can easily run down
together with water to suppress a thermal storage effect on the
surface of the building board.
[0026] Since the hydrophilic coating film is transparent, the
thermal insulation properties of the building board can be secured
without the function of the insulating coating film being
impaired.
[0027] In the method for producing the building board, it is
preferable that the temperature of the coating film is not more
than 130.degree. C. when the coating film is dried in the step of
forming the insulating coating film and the step of forming the
clear coating film. In this case, while reliably securing the
hollow state of the organic hollow particles, it is possible to
form the insulating coating film. Therefore, the thermal insulation
properties of the building board can be reliably obtained.
Furthermore, when the coating film is dried, volatilization of the
water-soluble solvent contained in the insulating paint is easily
suppressed. Therefore, the insulating coating film can be reliably
homogenized.
[0028] It is preferable that the temperature of the coating film is
set to 40 to 110.degree. C. when the coating film is dried in the
step of forming the insulating coating film and the step of forming
the clear coating film in consideration of the heat resistant
temperature of the organic hollow particles.
[0029] The method for producing the building board may further
include a step of forming a hydrophilic coating film in which a
hydrophilic paint is applied to the surface of the clear coating
film and then dried to form the transparent hydrophilic coating
film as the outermost layer. In this case, the appearance design of
the building board can be maintained for a long time.
EXAMPLES
Example 1
[0030] An example of the building board and the method for
producing the building board described above will be described with
reference to FIG. 1.
[0031] A building board 1 of the present example includes a base
material 2, an insulating coating film 3 for covering a surface of
the base material 2, and a transparent clear coating film 4 for
covering the insulating coating film 3.
[0032] The insulating coating film 3 contains a coating film
forming material, organic hollow particles, and a water-soluble
solvent.
[0033] The building board 1 can be used for, for example, exterior
walls or roofs of buildings.
[0034] Examples of the base material 2 include a ceramic siding
board such as a wood fiber-reinforced cement board, a
fiber-reinforced cement board, a fiber-reinforced cement calcium
silicate board, and a slag gypsum board; a metallic siding board;
and an ALC board.
[0035] A sealer layer 21 is formed on the surface of the base
material 2. The sealer layer 21 can be constituted by, for example,
an acrylic resin emulsion paint, an acrylic urethane resin-based
paint, an epoxy resin-based paint, a solvent-type moisture-curable
urethane, and a water dispersion-type isocyanate. Note that the
sealer layer 21 may be constituted by one layer, but can include
two or more layers.
[0036] The insulating coating film 3 having an average film
thickness of 5 to 500 .mu.m is formed on the sealer layer 21 of the
base material 2. It is more preferable that the average film
thickness of the insulating coating film 3 is 50 to 500 .mu.m.
Thereby, it is possible to obtain the sufficient thermal insulation
effect and, prevent the insulating coating film 3 from being easily
cracked due to a long drying time.
[0037] Examples of the coating film forming material s that mainly
constitute the insulating coating film 3 include a synthetic resin
such as an acrylic resin, a silicone resin, a fluororesin, an
acrylic silicone resin, a polyurethane resin, and an epoxy resin.
The organic hollow particles are mixed and dispersed in this
coating film forming material.
[0038] The organic hollow particles include at least one of
acrylonitrile, methacrylonitrile, vinylidene chloride, acrylic
ester, and styrene. The average hollow ratio of the organic hollow
particles is 80% or more. The average hollow ratio of the organic
hollow particles is more preferably 90% or more.
[0039] It is preferable that the content of the organic hollow
particles is 0.01 to 5.0 parts by mass in consideration of the
thermal insulation effect and coating strength. Here, the content
of the organic hollow particles represents the ratio of organic the
solid content forming the membrane of the organic hollow particle
with respect to 100 parts by mass of the paint solid content
contained in the entire insulating coating film. The same applies
hereinafter.
[0040] It is preferable that the average particle diameter of the
organic hollow particles is 5 to 50 .mu.m in consideration of the
thermal insulation effect and coating strength.
[0041] The water-soluble solvent is contained in the insulating
coating film 3. That is, in the building board 1 obtained finally
by producing steps described below, the insulating coating film 3
contains the water-soluble solvent. The content of this
water-soluble solvent is 0.1 to 10 parts by mass with respect to
100 parts by mass of the solid content of the insulating coating
film 3. Thereby, the entire insulating coating film 3 can be
reliably formed homogeneously.
[0042] The water-soluble solvent includes, at least one of a
glycol-based solvent and a glycol ether-based solvent. That is,
examples of the water-soluble solvent include ethylene glycol,
propylene glycol, diethylene glycol, dipropylene glycol N-butyl
ether, and tripropylene glycol monomethyl ether, or a mixture
thereof.
[0043] Furthermore, the insulating coating film 3 contains pigments
and serves as a color layer as well. Note that the insulating
coating film 3 can also be a coating film containing no
pigments.
[0044] The clear coating film 4 is formed of a water-soluble paint.
Examples of this water-soluble paint include an acrylic silicone
resin emulsion paint, an acrylic resin emulsion paint, a silicone
resin-based paint, an acrylic urethane-based paint, a
fluororesin-based paint, and polyurethane resin-based paint.
[0045] When the building board 1 of the present example is
produced, the step of forming the insulating coating film and the
step of forming the clear coating film described below are
performed.
[0046] In the step of forming the insulating coating film, an
insulating paint is applied to a surface of the base material 2
(surface of the sealer layer 21) and then dried to form the
insulating coating film 3.
[0047] In the step of forming the clear coating film, a clear paint
is applied to a surface of the insulating coating film 3 and then
dried to form the clear coating film 4.
[0048] The insulating paint is obtained by mixing and dispersing
the organic hollow particles in the coating film forming material
and contains the water-soluble solvent.
[0049] The specific materials of the coating film forming material,
the organic hollow particles, and the water-soluble solvent that
are contained in the insulating paint, and the clear paint are as
described above. The boiling point of the water-soluble solvent is
higher than the temperature of the coating film when the coating
film is dried in the step of forming the insulating coating film
and the step of forming the clear coating film. Conversely, the
temperature of the coating film when the coating film is dried in
the step of forming the insulating coating film and the step of
forming the clear coating film is set to less than the boiling
point of the water-soluble solvent. Specifically, the temperature
of the coating film when the coating film is dried is not more than
130.degree. C.
[0050] Next, the effect of the present example will be
described.
[0051] In the building board 1 described above, the insulating
coating film 3 is containing the mixed and dispersed organic hollow
particles. Thereby, the thermal insulation function is provided to
the insulating coating film 3. Since the organic hollow particles
include an organic material, the hollow ratio thereof tends to
become high. Therefore, the thermal insulation properties of the
insulating coating film 3 can be improved.
[0052] Since the insulating coating film 3 contains a water-soluble
solvent, the homogeneous insulating coating film 3 can be formed.
That is, the water-soluble solvent is contained in the insulating
coating film 3, so that heat is easily transmitted to the entire
coating when the insulating paint is dried. Therefore, the
homogeneous insulating coating film 3 can be formed. Thereby, the
homogeneous thermal insulation effect can be obtained by the
insulating coating film 3 all over the building board 1.
[0053] The boiling point of the water-soluble solvent is higher
than the temperature of the coating film when the coating film is
dried in the step of forming the insulating coating film and the
step of forming the clear coating film. Therefore, even after the
coating film is dried in each step, the water-soluble solvent
remains sufficiently and can contribute to the formation of the
homogeneous insulating coating film.
[0054] The water-soluble solvent includes at least one of a
glycol-based solvent and a glycol ether-based solvent, and can
effectively achieve the formation of the homogeneous insulating
coating film 3. That is, the glycol-based solvent and glycol
ether-based solvent have a high boiling point and tend to remain
until the end of the step of forming the insulating coating film.
Therefore, the glycol-based solvent and glycol ether-based solvent
may contribute to homogenization of the insulating coating
film.
[0055] The temperature of the coating film is set to not more than
130.degree. C. when the coating film is dried in the step of
forming the insulating coating film and the step of forming the
clear coating film, and therefore it is possible to form the
insulating coating film while reliably securing the hollow
structure of the organic hollow particles. Accordingly, the thermal
insulation properties of the building board 1 can be reliably
obtained. Furthermore, when the coating film is dried,
volatilization of the water-soluble solvent contained in the
insulating paint is easily suppressed. Therefore, the insulating
coating film 3 can be reliably homogenized.
[0056] Since the organic hollow particles include at least one of
acrylonitrile, methacrylonitrile, vinylidene chloride, acrylic
ester, and styrene, it is possible to especially stably obtain the
organic hollow particles in which the hollow ratio is high.
[0057] Since the average hollow ratio of the organic hollow
particles is 80% or more, the insulating coating film 3 can be
provided with a sufficient thermal insulation effect.
[0058] Since the building board 1 includes the transparent clear
coating film 4, the weatherability of the building board 1 can be
improved without the thermal insulation effect by the insulating
coating film 3 being inhibited.
[0059] As described above, with the present example, a building
board having superior thermal insulation properties and
weatherability, and a method for producing the building board can
be provided.
Example 2
[0060] As shown in FIG. 2, the present example is an example in
which a transparent hydrophilic coating film 5 is formed as an
outermost layer so as to cover the clear coating film 4.
[0061] The hydrophilic coating film 5 can be made of, for example,
silica, colloidal silica, and fumed silica.
[0062] When the building board 1 of the present example is
produced, a step of forming the hydrophilic coating film as
described below may be added to the step of forming the insulating
coating film and the step of forming the clear coating film in the
producing method of Example 1. That is, in the step of forming the
hydrophilic coating film following the step of forming the clear
coating film, a hydrophilic paint is applied to a surface of the
clear coating film 4 and then dried to form the transparent
hydrophilic coating film 5 as the outermost layer.
[0063] Here, a solution containing, for example, dispersed silica,
colloidal silica, and fumed silica can be used as the hydrophilic
paint.
[0064] Other respects are the same as those in Example 1.
[0065] In the case of the present example, an appearance design of
the building board 1 can be maintained for a long time. That is,
the hydrophilic coating film 5 is formed as the outermost layer, so
that, even if dirt is attached to the surface of the building board
1, water is absorbed into the hydrophilic coating film 5, and the
stain runs down together with water, by water being poured on the
surface of the building board 1 or by rainwater falling thereon.
Therefore, the appearance of the building board 1 can be maintained
for a long time. Furthermore, dirt attached to the surface of the
building board 1 can easily run down together with water to
suppress a thermal storage effect on the surface of the building
board 1.
[0066] Since the hydrophilic coating film 5 is transparent, the
thermal insulation properties of the building board 1 can be
secured without the function of the insulating coating film 3 being
impaired.
[0067] Other effects that are the same as those in Example 1 are
included.
EXPERIMENTS
[0068] The present example is an example in which the thermal
insulation properties of the building boards shown in Example 1 and
Example 2 described above are evaluated.
[0069] As shown in Table 1, the building boards of Example 1 or
Example 2 are produced as Samples 1 to 5 by variously changing the
insulating coating film (insulating paint), the clear coating film
(clear paint), and the hydrophilic coating film (hydrophilic
paint).
[0070] Furthermore, as shown in Table 2, the building boards of
Example 1 in which an insulating coating film (insulating paint)
has a constitution different from that of the insulating coating
film shown in Example 1 are produced as Samples 6 to 10.
[0071] Note that, in all the samples, the base material is a wood
fiber reinforced cement board, and the surface thereof is coated
with an acrylic resin emulsion paint (white) to form the sealer
layer. The insulating coating film is formed on the sealer layer.
Sample 5 contains no pigments, and all the others contain white
pigments. That is, the insulating coating film of Sample 5 is
transparent, and the insulating coating film is a white color layer
in all the other samples.
[0072] Details of the samples are as described in Table 1 and Table
2. In Samples 1 to 9, the coating film forming materials in the
insulating coating film (insulating paint) and in the clear coating
film (clear paint) include acrylic silicone emulsion. Sample 10 is
provided with no clear coating film. The hydrophilic coating film
of Sample 5 includes silica, and a solution containing dispersed
colloidal silica is used as the hydrophilic paint for forming the
hydrophilic coating film. The hollow particles of Sample 2 include
vinylidene chloride and acrylonitrile. The hollow particles of
Sample 3 include methacrylonitrile and methyl acrylate.
[0073] The hollow particles that is mixed and dispersed in the
insulating coating film (insulating paint) of Sample 6 are
ceramics. Solid particles are mixed and dispersed in the insulating
coating film (insulating paint) of Sample 8 instead of the hollow
particles.
[0074] Furthermore, in Table 1 and Table 2, the content of the
hollow particles (solid particles) and the content of the
water-soluble solvent are represented by parts by mass with respect
to 100 parts by mass of the paint solid content.
[0075] Problems such as production of cracks, deterioration of the
thermal insulation performance, and an appearance inferiority
occurred in the insulating coating film of Sample 9 in which the
insulating paint contained no water-soluble solvent.
[0076] The thermal insulation effect test was performed on the
building boards of Samples 1 to 10.
[0077] A lamp irradiating method was used as the testing method.
That is, the sample surface was irradiated with light by a halogen
lamp of 100 V and 150 W disposed at a position 10 cm away from the
sample surface. When the sample surface was continuously irradiated
with light for 10 minutes, a temperature of the sample surface was
measured using a radiation thermometer. The results are shown in
Table 1 and Table 2.
TABLE-US-00001 TABLE 1 Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
Insulating Hollow Composition Acrylonitrile Vinylidene
Methacrylonitrile Acrylonitrile Acrylonitrile paint particles
chloride and and acrylonitrile methyl acrylate Average 20 20 40 15
15 particle diameter (.mu.m) Average hollow 98 98 98 98 98 ratio
(%) Content 2.0 5.0 0.5 2.0 2.0 (parts by mass) Water-soluble
Solvent type Ethylene glycol Propylene glycol Diethylene glycol
Dipropylene Tripropylene solvent glycol N-butyl glycol ether
monomethyl ether Content 2.0 0.2 10.0 2.0 2.0 (parts by mass)
Coating film Composition Acrylic silicone Acrylic silicone Acrylic
silicone Acrylic silicone Acrylic silicone forming emulsion
emulsion emulsion emulsion emulsion material Insulating Film
thickness (.mu.m) 50 30 500 50 50 coating film Clear coating film
Acrylic silicone Acrylic silicone Acrylic silicone Acrylic silicone
Acrylic silicone emulsion emulsion emulsion emulsion emulsion
Hydrophilic coating film Absent Absent Absent Absent Present
Physical Surface temperature (.degree. C.) 55 56 50 54 54
properties Gloss retention ratio Good Good Good Good Good
TABLE-US-00002 TABLE 2 Sample 6 Sample 7 Sample 8 Sample 9 Sample
10 Insulating Hollow Composition -- Ceramic Methyl acrylate
Acrylonitrile Acrylonitrile paint particles (solid) Average -- 150
20 20 20 particle diameter (.mu.m) Average hollow -- 30 0 98 98
ratio (%) Content -- 5.0 2.0 2.0 2.0 (parts by mass) Water-soluble
Solvent type -- Propylene glycol Ethylene glycol -- Ethylene glycol
solvent Content -- 2.0 2.0 -- 2.0 (parts by mass) Coating film
Composition Acrylic silicone Acrylic silicone Acrylic silicone
Acrylic silicone Acrylic silicone forming emulsion emulsion
emulsion emulsion emulsion material Insulating Film thickness
(.mu.m) 20 50 100 100 50 coating film Clear coating film Acrylic
silicone Acrylic silicone Acrylic silicone Acrylic silicone Absent
emulsion emulsion emulsion emulsion Hydrophilic coating film Absent
Absent Absent Absent Absentt Physical Surface temperature (.degree.
C.) 65 63 63 60 55 properties Gloss retention ratio Good Good Good
Good Poor
[0078] As shown in Table 1 and Table 2, the surface temperatures of
Samples 6 to 9 reached 60 to 65.degree. C., whereas the surface
temperatures of Samples 1 to 5 fell within the range of 50 to
56.degree. C. That is, the constitutions of Example 1 and Example 2
can be used to reliably suppress rise in temperature of the
building board, and it can be said that the thermal insulation
properties thereof can be improved thereby.
[0079] Weatherability of the building board was evaluated.
Weatherability thereof was evaluated using the degree of changes of
the gloss value (gloss retention ratio), as an evaluation method,
on the surface of the building board before and after a
predetermined durability test was performed.
[0080] Specifically, the test below was performed using Samples 1
to 10 described above.
[0081] First, gloss values at random five points on the surface of
the building board (coating surface) were measured using a
hand-held gloss checker "Gloss Checker IG-320" manufactured by
HORIBA, Ltd. The average of these values was taken as an "initial
average gloss value".
[0082] Next, an accelerated test (cycle of irradiation for 4 hours
and wetting for 4 hours) was performed on each sample for 800 hours
using "Metal Weather Meter" manufactured by Daipla Wintes Co., Ltd.
Here, the irradiation condition is set to an irradiation intensity
of 1,100 W/m.sup.2, an irradiation distance of 240 mm, and a black
panel temperature of 63.degree. C. The wetting condition is set to
a condensation temperature of 30.degree. C. and a condensation
humidity of 98%, and the samples were showered for 10 seconds
before and after condensation.
[0083] After the accelerated test described above, gloss values at
random five points on the sample surface (coating surface) were
measured using the above hand-held gloss checker similarly to
before the accelerated test, and the average of these values was
taken as an "average gloss value after weatherability test".
[0084] A gloss retention ratio was calculated using the calculation
formula below.
Gloss retention ratio(%)=(average gloss value after weatherability
test)/(initial average gloss value)
[0085] The gloss retention ratio calculated was evaluated as
described below, and the results of evaluation were described in
Table 1 and Table 2.
[0086] Good: the gloss retention ratio is 80% or more.
[0087] Fair: the gloss retention ratio is 50% or more but less than
80%.
[0088] Poor: the gloss retention ratio is less than 50%.
[0089] As shown in Table 1 and Table 2, the gloss retention ratio
of Sample 10 including no clear coating film was less than 50%,
whereas all of the gloss retention ratios of Samples 1 to 9
including the clear coating film were 80% or more. That is, Samples
1 to 9 including the clear coating film retain the initial gloss
even after the weatherability test (accelerated test) is performed
thereon, and it can be said that Samples 1 to 9 have superior
weatherability.
[0090] These results show that weatherability can be improved by
forming the clear coating film.
* * * * *