Foamable heat insulating compositions containing alkali silicate and alumina cement

A process for manufacturing inorganic heat insulating material by mixing up water-soluble alkali silicate, alumina cement, metal base foaming agent and foam stabilizing agent into pasty state under presence of water. The heat insulating material manufactured by this process is of the class useful for heat insulating walls of buildings and for heat insulating plates incorporated in machinery.

BACKGROUND OF THE INVENTION 
This invention relates to a process for manufacturing a novel inorganic 
heat insulating material, more particularly to a novel, useful process for 
stably yielding, in a short period of time, an inorganic heat insulating 
material containing uniform foams, which foams and hardens simply by 
mixing up the ingredients into pasty state, even without any heating 
operation. 
There have conventionally been various proposals for obtaining inorganic 
foam materials based upon aqueous solution of alkali silicate. Among such 
known processes there are, for example, a process for foaming the solution 
by directly heating same, a process of first mixing to the solution a 
foaming agent as will give rise a gas upon heating and then getting the 
mixture to gel followed ultimately by foaming up the mixture gel by means 
of heating same, and a process of first mixing to the solution a hardening 
agent such for instance as silicofluoride followed by heating the mixture 
thus to hardening and foaming same. All such known processes essentially 
require heating (normally in the range of 200.degree.-900.degree. C.) for 
obtaining the foamed material. Namely, the alkali silicates and the 
foaming agents never cause foaming reaction at the normal temperature, and 
heating is indispensable for the foaming. It is yet more to be noted that 
the foamed product obtained by any of such processes contains 
water-soluble alkali components as will easily dissolve out upon contact 
with water thus for markedly impairing the structural strength of the 
foamed product, which has, therefore, very narrow scope of application as 
the heat insulating material, becuase of such low resistance to water by 
nature. 
In the field of concrete and mortar, inorganic lightweight materials highly 
resistant to water and with high mechanical strength are conventionally 
known, for instance as lightweight concrete, lightweight mortar or the 
like, but most of them are made simply by incorporating proper lightweight 
aggregate such as perlite, vermiculite or the like. It is also a known 
process to mix metal aluminum and water with cement, to knead up the 
mixture and to submit the mixture under heat and pressure in an autoclave, 
thus for causing exothermic hydraulic reaction with simultaneous foaming 
by hydrogen gas generation, but this process requires troublesome 
operations as curing in the autoclave, and the time required for the 
foaming and hardening is very long, particularly the hardening normally 
requiring quite long as one whole week or so. It should further be noted 
that the various processes as mentioned above can hardly provide the 
foamed product sufficiently light in weight, the best lightweight 
conventional product having the density of more than 0.5 specific gravity. 
The present invention has as its object to provide a novel process for 
manufacturing a useful inorganic heat insulating foamed material 
eliminating all the drawbacks of the conventional processes for 
manufacturing such material. 
In order to attain the object, the process for manufacturing the inorganic 
heat insulating material according to this invention is characterized by 
mixing up into a pasty state, under presence of water, the ingredients 
comprising: (A) water-soluble alkali silicate (hereinafter referred to as 
ingredient A); (B) alumina cement (hereinafter referred to as ingredient 
B); (C) metal base foaming agent (hereinafter referred to as ingredient 
C); and (D) foam stabilizing agent (hereinafter referred to as ingredient 
D). 
One of the most prominent features of this invention is to easily yield the 
desired heat insulating material under normal temperature and normal 
pressure simply by mixing up the said ingredients A-D into pasty state, 
even without any heating operation subsequent to the mixing. To note 
further, foaming reaction of the said mixture requires only short period 
of time, normally in the range of 5-60 minutes, which is defined almost 
definitely by the composition of the mixture, and subsequent hardening 
proceeds also rapidly, normally to complete within 24 hours. Furthermore, 
application of the mixture in pasty state as mentioned above allows use of 
the casing mould or frame almost in any complicated shape without causing 
difficulty, thus enabling to easily form the product in any design as 
desired. Foaming pressure of the paste is rather low, as will permit to 
use even corrugated paper board for the casting wall, thus requiring no 
specific casting frame of substantial strength, and the paste can be 
applied by pouring into the place desired to be heat insulated, simply 
with proper confinement walls. The pasty mixture according to this 
invention is further characterized by the excellent stability of the 
foaming reaction as is little influenced by the ambient conditions as 
climate or the like, and it provides the possibility of regulating the 
foaming reaction time, by properly regulating the composition ratio of the 
said ingedients A-D, which may thus be set and then kept almost uniform 
and constant to the desired value within the said possible range, and also 
of easily regulating the foaming overrun ratio, thus the bulk density of 
the product. With respect to the bulk density, in particular, extremely 
low density can hereby be provided, as in the range of about 0.1-0.3 
g/cm.sup.3 as has never been possible with respect to the conventional 
autclaved lightweight concrete, generally called ALC and known as with 
excellent mechanical strength; with this novel product of such low density 
still having sufficient mechanical strength for practical use as the heat 
insulating material. As a matter of course, here is no difficulty in 
manufacturing the product with similar bulk density and similar mechanical 
strength just as the said ALC, and such novel product can now be of half 
as low heat conductivity coefficient as compared with the ALC. 
The inorganic heat insulating material provided by the process of this 
invention has the foams of substantially uniform diameters, in the 
possible range of 0.5-10 mm as the case may be, and the foam structure is 
very robust. This material has thus excellent heat insulation, 
noncombustibility, resistance to heat, and interception of fire flame. 
Especially, the heat resistance is quite excellent as is proved by the 
test of keeping the samples in a 700.degree. C. furnace for 24 hours, 
resulting no appreciable deformation of the samples at all. Still more, 
this material according to this invention has remarkably excellent 
resistance to water, acid and alkali, as well as the mechanical strength, 
as are not realized by the conventional foamed alkali silicate material. 
The reason why the novel inorganic heat-insulating material with the 
properties as mentioned above can be manufactured according to the process 
of this invention simply by mixing up the said ingedients A-D is not very 
clear as at this moment, but it might perhaps be as follows: Upon mixing 
up into the paste, most of the ingredient B, namely alumina cement (or the 
same together with portland cement), reacts upon water to gradually be 
hardened as hydraulic reaction, while a part of the ingredient A, namely 
water-soluble alkali silicate, as well as of the said ingredient B, 
undergoes hydrolysis in the paste to give alkaline agents, such as alkali 
hydroxides, and the groups such as SiO.sub.3.sup.2- and AlO.sub.2.sup.-, 
with said alkaline agents then coacting with the ingredient C, namely 
metal base foaming agent, to promote the foaming action for generating the 
minute foams within the paste or the hardening ingredient B, and with said 
groups such as SiO.sub.3.sup.2- gradually undergoing gellation in parallel 
with said foaming reaction, for being intimately packed up within the mass 
of the hardened ingredient B, thus resulting, according to this 
assumption, in improved mechanical strength of the foamed product as 
solidified. As for the ingredient D, namely the foam stabilizing agent, it 
is assumed that it will, while the hydraulic reaction of the ingredient B 
and the foaming reaction between the ingredients A/C and B/C proceed, keep 
the dispersion of the ingredient C uniform within the entire bulk in spite 
of its inclination to otherwise gradually be locally biased, thus securing 
the function for stabilizing the foaming reaction and preventing 
localization as well as serial continuation of the minute foams as 
generated. Be the matter what it may, this invention enables to stably and 
easily manufacture the inorganic heat insulating material with excellent 
characteristics, simply by mixing up the ingredients uniformly, under 
normal temperature and normal pressure, thus providing enormous industrial 
value.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In this invention, it is essential and indispensable to use soluble alkali 
silicate as the ingredient A, only herewith yielding the inorganic heat 
insulating material as expected. Such heat insulating material can not be 
made from insoluble or hardly or badly water-soluble alkali silicate, such 
as the common anhydride liquid glass cullet. As alkali metal to constitute 
this ingredient A, various examples may be mentioned such as Li, Na, Ka, 
Rb and so forth, among them especially preferable being Na, Ka etc., since 
such are available quite economically and yet remarkably promote the 
foaming function. So long as is water-soluble, the ingredient A puts no 
specific limitation as to the composition and the mol ratio between the 
metal oxide (represented as R.sup.I.sub.2 O) and SiO.sub.2, but the 
preferable range of the mol ratio SiO.sub.2 /R.sup.I.sub.2 O lies 
generally over 1.5-4.0, with the most preferable range being 1.8-3.0, 
since such range will yield the product heat insulating material 
especially good both in resistance to water and in mechanical strength. 
One kind of the ingredient A solely or two or more kinds combined may as 
well advantageously be used either in the form of powder or in the form of 
aqueous solution, but in view of convenience in preparing the paste, it is 
preferable to use same in the form of aqueous solution with the solid 
concentration of 20% or more, normally in the range of about 20-60%. Thus, 
when the ingredient A is used in the form of aqueous solution of the 
concentration in such range, the paste with proper flowability can then be 
easily prepared simply by admixing same with other ingredients B-D, and 
shrinkage coefficient for the hardening can comparatively be moderate. 
The ingredient B is, as already mentioned, alumina cement which is a 
hydraulic cement containing CaO and Al.sub.2 O.sub.3 as the main 
components thereof, and any one of those commercially available with 
various composition ratios may be used as this ingredient B in the present 
invention. The calcium aluminate component of the alumina cement may take 
the various forms such for instance as tri-calcium aluminate 
(3CaO.Al.sub.2 O.sub.3), calcium aluminate (CaO.Al.sub.2 O.sub.3), calcium 
di-aluminate (CaO.2Al.sub.2 O.sub.3) and calcium hexa-aluminate 
(CaO.6Al.sub.2 O.sub.3), and any one of them as shown in such composition 
formula can advantageously be used in this invention for realizing the 
effect as expected, which can however not be attained with other cement 
material than the alumina cement. Particularly preferable composition for 
the alumina cement is in the range of CaO in 36-59% and Al.sub.2 O.sub.3 
in 39-53%, with possibility of some harmless impurities as Fe.sub.2 
O.sub.3 in 1-16% and SiO.sub.2 in 3-9%. Any one type of the said alumina 
cement alone or two or more types of them combined may as well be used, 
and it is preferable to use same in a powdery form normally in size under 
100 micron mesh. In this invention, it is also possible to add a certain 
amount of portland cement to the said alumina cement, as the ingredient B. 
By portland cement it is meant normal type of cement containing calcium 
silicate as the main hydraulic component, and in the trade there are 
classifications of those commercially available such for instance as 
normal portland cement, rapid hardening portlend cement, ultra rapid 
hardening portland cement and moderate heat portland cement, with some 
differences in the composition therebetween, and any portland cement may 
be used in this invention. Use of such portland cement, any one kind or 
two or more kinds, in a powdery form under about 100 micron size, in 
combination with the said alumina cement, has the effect of shortening the 
time required for hardening the paste of this invention, but too much dose 
will make the hardening too short and is apt to result in difficulty of 
good foaming. It is therefore preferable to use the portland cement in 
solid weight ratio of under 30 parts to 100 parts of alumina cement, most 
preferable range being further restricted to be under 20 parts, since such 
will yield the heat insulating material especially good in resistance to 
water. 
As the ingredient C of this invention, it is possible to use various metal 
elements and metal alloys or intermetallic compounds. As the metal 
element, any member belonging to groups I B, II A, II B, III A, III B, IV 
A, IV B, V A, VB, VI B, VII B and VIII in the periodic table may be used, 
of which the elements belonging to the 3rd to 5th groups are preferable. 
Suitable metal elements may be mentioned by way of example as Mg, Ca, Cr, 
Mn, Fe, Co, Ni, Cu, Zn, Al, Ga, Sn, and Sb, of which the most preferable 
are Al, Mg, Fe, Ni, and Zn, in view of easy avilability and good 
reactivity. In this invention, semi-metallic elements such as B, Si etc. 
may as well be used just like the metallic elements mentioned above. 
Furthermore, alloys of the said metals or intermetallic compounds 
(compounds with chemical bonds in between metals or between metal and 
nonmetal) may also be used in this invention just like the said metals. By 
way of example, typlical alloys or the intermetallic compounds may be 
shown as Al-Si, Al-Ti, Al-Mn, Al-Cu-Si, Al-Cu, Zn-S, Zn-Sn, Sn-Fe, Cu-Sn, 
Su-Si, Cu-Pb, Cu-Ni, Fe-Ni, Fe-Mn, Fe-Cr, Fe-Si, Mn-P, Si-Ni, Co-Sb and 
Mn-Ag. It is preferable to use the ingredient C, either one kind or two or 
more kinds, normally in a powdery form, especially under 150 micron size. 
As the ingredient D of this invention, namely the foam stabilizing agent, 
it is possible to use an inorganic substance chosen from silica gel, 
zeolite, artificial zeolite, carbon black, active carbon, alumina gel, 
talc and mica, or an organic substance such as animal protein as 
conventionally known as foaming agent for cement bulk, dimethyl silicone 
derivative and so forth. The ingredient D as such has the function of 
keeping the dispersion of the ingredient C uniform within the entire bulk 
and stabilizing the foaming reaction, and is thus effective for generating 
minute, uniform foams. If the ingredient D is an inorganic substance, it 
is preferable to use same in a powdery form normally in size under 200 
micron mesh. The composition ratios of the ingredients A-D may vary in 
accordance with what kind of substances compose each of the ingredients, 
concentration of the ingredient A when in particular the same is used in 
form of the aqueous solution, bulk density and strength of the product as 
desired, and casting condition for forming up the desired product; but the 
guideline may normally be as follows: Namely, taking the solid portion of 
the ingredient A as the basis, thus to 100 parts in weight thereof, the 
ingredient B may have the solid portion in the range of about 100-700 
parts in weight, preferably 140-500 parts in weight, and the ingredient C 
may be in the range of about 0.5-35 parts in weight. As for the ingredient 
D, it may have the solid portion in the range of about 5-50 parts in 
weight if it is an inorganic substance, or about 0.1-3 parts in weight if 
organic. Generally speaking, presence of the ingredient A in too much 
excess tend to cause unstability of the foaming and of the bulk density, 
thus to yield the product heat insulating material with uneven foam 
dispersion and low resistance to water; while too much presence of the 
ingredient B tends to cause too high paste viscosity in the paste 
preparation, thus to lower the workability. As for the ingredient C, too 
small amount thereof will cause insufficient foaming thus to result in 
heavy bulk density (about 1.0 specific gravity or more), while too much 
amount thereof will cause excessive foaming in large bubbles within the 
product which is thus difficult to have the strength as desired. As for 
the ingredient D, supposing first the same is an inorganic substance, too 
small amount thereof will cause uneven foaming, while too much amount 
thereof will make the paste preparation difficult. In case the same is an 
organic substance, too much presence of such will cause serially 
continuous foams thus to result in low heat insulating effect. 
In this invention, the ingredients A-D are mixed up under presence of water 
into pasty state, as mentioned already. No particular limitation is put to 
the method of the mixing, and it is possible to simply mix up the 
ingredients A-D together with proper amount of water all at one time, but 
it is advantageous, for ease of operation, to first mix in the 
predetermined ratios the ingredients B-D each having been kept in solid 
powdery state, and thereafter to admix such mixture into the ingredient A 
which is in the form of aqueous solution. As the ingredients B and C will 
start hardening and foaming reactions in a very short period of time after 
the mixing, these two ingredients are preferably added simultaneously to 
compose the paste in the preparation thereof. In this preparation of the 
paste by mixing up the ingredients A-D, it is preferable to use such 
proper amount of water as will ultimately result in that the ingredient A 
and total water in the paste is same as would make an aqueous solution of 
the ingredient A in concentration within the range of 20-60%, preferable 
20-50%, based on such total solution weight, should these two have been 
mixed alone, and it is also preferable to make up the paste normally with 
agitation or the like thus to have the solid particles dispersed 
uniformly. 
At all events, it is essential in this invention to mix up the ingredients 
A-D into pasty state under presence of water, since no sufficient foamed 
and hardened material will yield without such pasty state. It is here to 
be understood that the "paste" as so far referred to means a soft, viscous 
dispersion of solid particles, with the viscosity of the paste in this 
invention normally in the range of about 0.5-300 P at 25.degree. C. 
To the paste as prepared as above, it is possible to add, when needed, 
lightweight aggregate powder normally kilned over 1000.degree. C., for 
instance as foam silica, perlite, vermiculite, SHIRASU-balloon (i.e. 
volcanic soil mainly in Kyushu, southern island of Japan, Kilned to form 
balloon-like particles), thus for further lowering the bulk density of the 
product. Yet more, it is also possible to further add, for the purpose of 
filling and increasing the volume and/or of reinforcement, various 
conventional fillers such as gypsum, fused quartz, sintered cristobalite, 
silica powder, fly ash, alumina powder and so forth, but care must then be 
paid as to the kind and volume of such fillers so that proper reaction 
mode of the said essential ingredients A-D should not be affected. 
Further, if gypsum is chosen, it secures the function for stabilizing the 
foaming reaction in addition to filling and increasing effects. 
According to this invention, both the hardening and foaming reactions 
concurrently start immediately after the paste is prepared by mixing the 
ingredients A-D and, when needed, the lightweight aggregate powder or the 
like as well. Such concurrent reactions of hardening and foaming proceed 
quite well under normal temperature and normal pressure even without any 
external heating, normally to end in about 5-60 minutes, and the hardening 
reaction will be completed within 24 hours. No need of heating and 
pressure according to this invention as mentioned above is in industrial 
view point quite advantageous, but it should be noted that the foaming and 
hardening reactions proceed at the temperature in the range of about 
5.degree.-90.degree. C., and it is possible, as a matter of course, to 
effect heating up to about 90.degree. C., in such case as particular 
promotion of the reaction is desired. In normal application, temperature 
range from the normal temperature to about 50.degree. C. is preferred. 
In such manner, inorganic heat insulating material is obtained according to 
this invention, which contains uniform foams, in size normally in the 
range of 0.5-10 mm diameter and which is of low specific gravity and of 
high strength and is excellent in view of water absorption coefficient, 
freezing and thawing stability, resistance to water, resistance to 
chemicals, heat insulation, heat resistance, resistance to fire flame and 
so forth. 
As the inorganic heat insulating material according to this invention has 
the various characteristics as mentioned heretofore, it may induce further 
novel advantages accordingly what the use may be. Mention is now given 
hereunder on some special examples of application, which are, of course, 
of no limitative nature: 
Central heating system has widely been spreading in recent years as heating 
means for the residential houses, hotels, hospitals and so forth. There, 
the heat source is hot water and duct pipes for the hot water are 
installed within the floors and walls and occasionally in the ceilings as 
well. Conventional art widely used there is to apply a thermal conductor 
plate such as aluminium foil on the inner room side surface of such wall 
etc. containing the hot water pipe and to apply an exterior metal plate on 
the building outer side thereof, with hard polyurethane foam poured 
therebetween as stuffing and heat insulating material. However, the 
polyurethan foam, being an organic susbtance, is weak to overheating and 
high temperature steam, and has in addition the vital defect of flashing 
up or scorching in smoke when attacked by flame in case of fire. It is 
also the drawback that curing or aging in irregular deformation is apt to 
develop internally at the boundaries with the said thermal conductor plate 
and the exterior metal plate, thus causing often to contain dew water 
there. 
Applying the inorganic heat insulating material according to this invention 
instead of such conventional hard polyurethane foam, its excellent 
resistance to fire, heat and flame will function for putting down fire 
hazard, should such occur, and the heat insulation effect itself is higher 
than with the polyurethane foam. Furthermore, it has good bonding 
characteristic to the thermal conductor plate and the metal plate, thus 
realizing good absorption of shock, and high working efficiency is attaned 
by the simple operation of pouring the paste. 
As is evident, similar advantages are likewise seen also in use for heat 
insulating walls not incorporated in such central heating system. Walls of 
the buildings in general, with exception of concrete structure, often 
contains hollow space in their structure, as is quite common in view both 
of reducing the costs for the reinforcement steel skeletons as well as 
pre-fabricated structures and PC wires, and of enchancing the heat 
insulation. It is now possible to form up heat insulating walls by pouring 
the past, to make the heat insulating material according to this 
invention, into the said hollow space. The inventors have performed 
various experiments with this respect, and have got there quite unexpected 
findings. It concerns the experiments where pneumatic feed pouring system 
is used as means of supplying the heat insulating material of this 
invention to the wall structure, thus pouring same into the hollow space 
within the wall through an aperture of proper size, which results in 
uniform foam mass even when poured into a hollow space with a slit of 
about 50 mm wide, with quite excellent "rising-up property", i.e. the 
property of the foaming heat insulating material to heap up vertically 
with increasing bulk volume during the foaming step, which bulk volume 
overrun ratio and the rising up raio being thus desired to be identical 
especially when the bottom area is confined to remain constant, and which 
reveals that such excellent rising up property is more prominent as the 
paste is poured more promptly after being mixed up. Generally speaking, 
width of the slit in the hollow space within building walls ranges from 
about 30 mm when narrow to 200 or 300 mm when broad, normally within the 
range of about 50-100 mm, and the height is, when modularized, under 5 m 
at the highest in view of the structural restriction, while width of the 
hollow space is less than 2 m. Assuming now a hollow wall with slit width 
100 mm, hollow space width 1 m and height 3 m, such is just an example of 
"casting plates with hollow space therebetween". It has so far been 
considered to be quite difficult in the prior art to attain the 3 m rising 
up by pouring the conventional plastic foam, and the foaming reaction then 
results in foams lacking uniformity, thus with poor heat insulating 
effect. In such instance, however, pouring the paste of this invention by 
means of pneumatic supplying system immediately after mixing up thereof 
has given the results sufficient in view both of the rising up property 
and uniformity of the foams. It is possible, therefore, to easily form up 
the walls excellent in heat insulation, shock absorption and resistance to 
water, not only in the buildings under construction but also in the 
existing buildings, simply by pouring the paste of this invention through 
an aperture as may be drilled in the top portion of the part in question. 
Such building structure with hollow space may be of various materials such 
as concrete, mortar, asbestos cement board, wooden fiber cement board and 
so forth, and in the possible case of metal plate or plastics plate, i.e. 
the material with poor bonding property, there will even then be no 
serious hampering against formation of heat insulating wall according to 
this invention, if paper is applied beforehand on the working surface. 
Among the various advantages over the foam plastics conventionally used for 
heat insulating walls, good bonding property should not be neglected. 
Making use of the good bonding action, it is possible to simply and easily 
perform the tiling work. It is conventional to form heat insulating tile 
walls by affixing tiles onto foam plastics surface thus to make use of the 
heat insulating function of the foam plastics. However, the foam plastics 
have rather poor bonding property themselves, and thus require good amount 
of adhesives. If the heat insulating material of this invention is used 
instead of such foam plastics for bonding tiles thereon, the working 
efficiency will then be improved with omission of adhesives, and 
additional effect of attaining excellent resistance to fire and to shock, 
as can never be expected with the foam plastics, may simultaneously be 
realized. 
In order to more clearly visualize the invention, some examples are given 
hereunder, in which the ingredients A-D are chosen from those as listed in 
Tables 1-4: 
Table 1 
______________________________________ 
Ingredient A 
Con- 
cen- 
tra- 
Mol ratio tion 
No. Substance SiO.sub.2 /R.sup.I.sub.2 O 
(%) Remarks 
______________________________________ 
A-1 aqueous solution 
2.0 20 Made by Osaka 
of natrium silicate Keisan Soda 
K.K 
A-2 aqueous solution 
3.0 30 Made by Osaka 
of Kalium silicate Keisan Soda 
K.K. 
A-3 aqueous solution of 
2.2 50 Reagent 
lithium silicate 
A-4 powder natrium 
3.2 80 A-1 dried and 
silicate powdered to 
40-150 
micron mesh. 
______________________________________ 
Table 2 
______________________________________ 
Ingredient B 
Mol 
ratio 
Al.sub.2 O.sub.3 / 
Mesh 
No. Article CaO (micron) 
Remarks 
______________________________________ 
B-1 DENKA High 1.57 5-100 Made by 
Alumina Cement The Electoro- 
Chemical 
Industrial Co., 
Ltd. 
B-2 DENKA High 0.85 5-100 Made by 
Alumina Cement II The Electoro- 
Chemical 
Industrial Co., 
Ltd. 
B-3 ASAHI Alumina 0.78 5-100 Made by 
Cement I Asahi Glass 
Company, Ltd. 
______________________________________ 
Table 3 
______________________________________ 
Ingredient C 
Mesh 
No. Metal(s) (micron) Remarks 
______________________________________ 
C-1 Si 1-50 Reagent Extra Grade 
C-2 Ni I-100 " 
C-3 Al 1-50 Powder for Paint, made by 
Toyo Aluminium K.K. 
C-4 A1--Cu 5-100 Reagent Extra Grade 
C-5 Fe--Si 5-100 " 
______________________________________ 
Table 4 
______________________________________ 
Ingredient D 
Substance Mesh 
No. (Article) (micron) Remarks 
______________________________________ 
D-1 active carbon 
5-50 Made by Taihei Chemical 
Industrial Corporation, Ltd. 
D-2 zeolite 10-100 Mined in North-Eastern region 
of Japan 
D-3 talc 10-150 Mined in Tajima region, 
Hyogo-Prefecture, Japan 
D-4 mica 20-200 Mined in North-Eastern region 
of Japan 
D-5 "Glufoam" -- Animal protein for cement 
foaming, made by 
Sun-Orient Chemical Co., 
Ltd. 
______________________________________ 
Properties of the inorganic heat insulating materials obtained by the 
experiments have been tested and measured in accordance with the methods 
as follows, with the ambient testing condition uniformly maintained in 
20.+-.2.degree. C. and 65.+-.10% relative humidity: 
(a) Bulk density: in accordance with JIS (Japanese Industrial Standard) 
A-1161 
(b) Water absorption coefficient: Shown in % weight ratio, in accordance 
with JIS A-1161 
(c) Compression strength: Shown in Kg/cm.sup.2, in accordance with JIS 
A-1161 
(d) Resistance to water: Judging outer appearance of the samples after 
soaking in water for 10 days, marked "-" if no change and "+" if any. 
(e) Resistance to acid: Judging outer appearance of the samples after 
soaking in 1 N HCl for 2 days, marked "-" if no change and "+" if any. 
(f) Resistance to alkali: Judged as to any change or not in outer 
appearance after soaking in saturated Ca(OH).sub.2 solution for 2 days. 
(g) Thermal conductivity: Shown in kcal/m.hr..degree.C., in accordance with 
JIS R-2616 
(h) Foam size: Shown in mm diameter, as measured with the foams appearing 
on cut surfaces of the samples 
(i) Resistance to heat: Judging deformation of the samples after keeping in 
650.degree. C. furnace for 24 hours, marked "+" if any deformation and "-" 
if no. 
and 
(j) Resistance to flame: Judging deformation of the samples after directly 
exposing to flame for 10 seconds, marked "+" if any deformation and "-" if 
no. 
EXAMPLE 1 
As the ingredient A, 100 grams of the aqueous solution A-1 were taken in a 
polyethylene continer (of 1.5 liter content). On the other hand, mixed 
powder was prepared by mixing up 100 grams of B-1, 5 grams of C-1 and 7 
grams of D-1, as the ingredients B, C and D, respectively. Uniform paste 
was then made by adding the mixed powder into the polyethylene container 
keeping the ingredient A and admixing same by agitation under normal 
temperature. The paste, subsequently kept in the container, gradually 
started foaming and the foaming completed in about 50 minutes. Foaming 
occured to exceed the brim of the polyethylene container. Inorganic heat 
insulating material 1 according to this invention was obtained by letting 
same stand thereafter for one entire day thus completing the hardening. 
Shown in Table 5 are the results of the time (in minutes) required for the 
foaming for thusly obtaining the heat insulating material and of the 
properties thereof as measured. 
EXAMPLES 2 and 3 
Inorganic heat insulating materials 2 and 3 were provided similarly as in 
Example 1, with mere exception of changing the ingredient A from A-1 to 
A-2 and A-3, respectively. Shown also in Table 5 are the foaming time and 
the properties of the respective heat insulating materials as so provided. 
EXAMPLE 4 
Mixed powder was provided by taking 50 grams of powder A-4 as the 
ingredient A, 100 grams of B-1 as the ingredient B, 5 grams of C-1 as the 
ingredient C and 7 grams of D-1 as the ingredient D, into a polyethylene 
container and admixing same. To the mixed powder were then added 50 grams 
of water and made into uniform paste by amixing with agitation under 
normal temperature. The paste, subsequently kept in the container, 
gradually started foaming and the foaming completed in about 15 minutes 
after mixing and agitation with water. Foaming occured to exceed the brim 
of the polyethylene container. Inorganic heat insulating material 4 
according to this invention was obtained by letting same stand thereafter 
for one entire day thus completing the hardening. Shown also in Table 5 
are the foaming time and the properties of the heat insulating material as 
so provided. 
Table 5 
______________________________________ 
Example (heat insulating 
material) No. 1 2 3 4 
Foaming time (minutes) 
50 45 50 48 
______________________________________ 
(a) 0.32 0.29 0.35 0.31 
(b) 0.2 0.3 0.3 0.2 
(c) 5.0 5.2 5.1 5.0 
(d) -- -- -- -- 
(e) -- -- -- -- 
Properties 
(f) -- -- -- -- 
(g) 0.07 0.07 0.08 0.07 
(h) 2-4 1-3 2-4 2-4 
(i) -- -- -- -- 
(j) -- -- -- -- 
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EXAMPLES 5 to 8 
Inorganic heat insulating materials 5 and 6 were provided similarly as in 
Example 1, with mere exception of changing the ingredient B from B-1 to 
B-2 and B-3, respectively. 
Likewise, inorganic heat insulating materials 7 and 8 were provided again 
similarly as in Example 1, with mere exception of modifying the ingredient 
B by adding, to the said amount of B-1, 5 grams and 10 grams, 
respectively, of portland cement as commercially available (made by Nihon 
Cement Co., Ltd., in the range of 30-75 micron mesh). Shown hereunder in 
Table 6 are the properties and the foaming time of the respective heat 
insulating materials as so provided. 
Table 6 
______________________________________ 
Example (heat insulating 
material) No. 5 6 7 8 
Foaming time (minutes) 
35 30 15 10 
______________________________________ 
(a) 0.30 0.25 0.27 0.24 
(b) 0.2 0.3 0.2 0.3 
(c) 4.8 5.0 4.8 5.1 
(d) -- -- -- -- 
(e) -- -- -- -- 
(f) -- -- -- -- 
Properties 
(g) 0.06 0.07 0.06 0.08 
(h) 1-3 2-3 1-3 2-4 
(i) -- -- -- -- 
(j) -- -- -- -- 
______________________________________ 
EXAMPLES 9 to 12 
Inorganic heat insulating materials 9 through 12 were provided again 
similarly as in Example 1, with mere exception of changing the ingredient 
C from C-1 to 5 grams of C-2 through C-5, respectively. Shown hereunder in 
Table 7 are the properties and the foaming time of the respective heat 
insulating materials as so provided. 
Table 7 
______________________________________ 
Example (heat insulating 
Material) No. 9 10 11 12 
Foaming time (minutes) 
48 51 45 47 
______________________________________ 
(a) 0.24 0.30 0.29 0.25 
(b) 0.3 0.4 0.2 0.3 
(c) 5.3 5.7 5.6 5.5 
(d) -- -- -- -- 
(e) -- -- -- -- 
Properties (f) -- -- -- -- 
(g) 0.07 0.06 0.05 0.07 
(h) 1-3 2-5 2-4 1-3 
(i) -- -- -- -- 
(j) -- -- -- -- 
______________________________________ 
EXAMPLES 13 to 16 
Inorganic heat insulating materials 13 through 16 were provided again 
similarly as in Example 1, with mere exception of changing the ingredient 
D from D-1 to 7 grams of D-2 through D-5, respectively. Shown hereunder in 
Table 8 are the results of the properties and the foaming time, as 
measured, of the respective heat insulating materials as so provided. 
Table 8 
______________________________________ 
Example (heat insulating 
material) No. 13 14 15 16 
Foaming time (minutes) 
49 47 50 51 
______________________________________ 
(a) 0.31 0.33 0.29 0.28 
(b) 0.3 0.4 0.2 0.3 
(c) 5.5 4.9 4.9 5.0 
(d) -- -- -- -- 
(e) -- -- -- -- 
Properties (f) -- -- -- -- 
(g) 0.08 0.07 0.05 0.07 
(h) 1-3 2-4 3-4 1-3 
(i) -- -- -- -- 
(j) -- -- -- -- 
______________________________________ 
EXAMPLES 17 to 19 
Inorganic heat insulating materials 17 to 19 were provided again similarly 
as in Example 1, but with further incorporation., as fillers, of 2 grams 
of fused quartz, sintered cristobalite and gypsum, respectively, in 
addition to the ingredients A-D as originally used. Shown hereunder in 
Table 9 are the results of the properties and the foaming time, as 
measured, of the respective heat insulating materials as so provided. 
Table 9 
______________________________________ 
Example (heat insulating 
material) No. 17 18 19 
Filler fused sintered 
quartz cristobalite 
gypsum 
Foaming time (minutes) 
45 45 45 
______________________________________ 
(a) 0.29 0.25 0.25 
(b) 0.2 0.3 0.2 
(c) 6.2 6.3 6.3 
(d) -- -- -- 
(e) -- -- -- 
Properties (f) -- -- -- 
(g) 0.06 0.07 0.06 
(h) 2-4 1-3 2-4 
(i) -- -- -- 
(j) -- -- -- 
______________________________________