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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to novel polyether polyols based on sucrose
and formitol. These polyols have a relatively low viscosity and are
particularly suitable for the production of rigid, closed-cell
polyurethane foams.
Rigid, closed-cell polyurethane foams are generally obtained by reacting a
polyether polyol with an aromatic polyisocyanate, such as crude
4,4'-diisocyanato diphenyl methane. Such polyurethane foams are
particularly suitable for the production of insulating materials, sandwich
structures, building panels and numerous other building elements.
The physical and mechanical characteristics of these foamed plastics depend
to a large extent upon the structure and molecular size of the polyethers
which are used. Polyethers derived from trihydric alcohols, such as
trimethylol propane or glycerin, have been used to make such rigid foams.
However, polyurethane foams obtained from such polyethers have poor
dimensional stability. Increasing the amount of cross-linking may improve
the quality of such rigid polyurethane foams; however, the thus-obtained
products are still unsatisfactory.
One approach to improving rigid polyurethane foams which has been
investigated is the use of high-functional polyether polyols based on
sucrose. However, these efforts have not been too successful due to the
number of technical problems encountered with conventional processes for
producing sucrose polyether.
It is known to react sucrose with alkylene oxide in an aqueous solution in
the presence of sodium hydroxide and ethylene oxide and subsequently
convert the product into sucrose hydroxy alkyl ethers (J. W. LeMaistre R.
B. Seymour, J. Org. Chem. 13,782 (1948)). In one process based on this
reaction, sucrose is reacted at elevated temperatures with ethylene oxide
or propylene oxide in a concentrated aqueous solution in the presence of a
potassium hydroxide catalyst (U.S. Pat. Nos. 3,055,085 and 3,153,002;
German Pat. No. 1,443,026). However, such processes are subject to
undesirable secondary reactions, such as partial hydrolysis of the
alkylene oxide by the water used as the reaction medium. When such
hydrolyzed alkylene oxides are used to form polyalkylene glycols, the
reaction mixture becomes very darkly colored. This dark coloring has a
disadvantageous effect upon the properties of polyurethane foams which are
produced from these sucrose hydroxy alkyl ethers. These secondary
reactions also result in a large amount of bifunctional, linear
by-products which reduce the functionality of the product polyethers (as
compared to the functionality of a pure sucrose polyol). As a result of
the large proportion of such by-products, the product sucrose polyethers
have limited suitability for the production of satisfactory polyurethane
foams. In fact, such by-product laden polyethers tend to yield brittle
foams of moderate strength having a non-uniform cell structure. Another
disadvantage of polyurethane foams obtained from such sucrose polyethers
is the low proportion of closed cells and consequent poor heat insulation
ability.
For these reasons, it has been attempted to alkoxylate sucrose in the
presence of xylene (U.S. Pat. No. 2,652,394) rather than water. However,
this process yields highly discolored products as a result of converting
the sucrose into caramel or carbonizing the sucrose.
It has been found that the production of large quantities of bifunctional
by-products may be reduced by a process wherein sucrose is first reacted
with from 4 to 8 mols alkylene oxide in a concentrated, aqueous solution
in the presence of potash lye. Substantially all of the water is then
removed from the reaction mixture and more alkylene oxide is added (German
Pat. No. 1,443,022). However, since a large quantity of the alkylene oxide
is reacted in the presence of relatively large amounts of water, the
disadvantages already mentioned with respect to the process of
alkoxylation without dehydration, also occur to a considerable extent in
this process. One of the disadvantages of these known processes which
employ an aqueous solution is that most of the sugar must be added at
temperatures which are approximately the same as the boiling point of
water or only slightly below. Another disadvantage of such processes is
that the rate of the alkylene oxide addition reaction is relatively slow
which greatly promotes the formation of by-products.
The combination of the required characteristics for rigid polyurethane
foams (i.e. a fine cell feature, dimensional stability in moist heat and
at cold temperatures) with outstanding flow behavior in the foaming
process and the required curing behavior (particularly curing rate and
formation of a hard peripheral area with an optimum adhesion to covering
layers), cannot be achieved by using either known polyether polyols based
on sucrose or sucrose glycerin mixtures or sorbitol as the starting
material.
U.S. Pat. No. 2,990,376 discloses that a polyol which is suitable for the
production of rigid polyurethane foams is obtained if small amounts of a
particular sucrose polyether are added to a glycerin polyether. Another
process for the production of rigid polyurethane plastics is suggested in
German Auslegeschrift No. 1,285,741. In this process, polyethers which
contain a carefully controlled ratio of sucrose and glycerin are used. The
foams obtained from either of these polyethers do exhibit a good
dimensional stability, but do not have the other required characteristics
of a suitable rigid polyurethane foam (particularly short in-mold times
and the ability to form hard surfaces with outstanding adhesion to
covering layers). Additionally, use of relatively expensive glycerin as
the starting material for polyethers is economically impractical.
German Offenlegungsschrift No. 2,639,083 discloses a method for the
preparation and use of formitol-polyethers. Polyethers which are prepared
according to this process are advantageously distinguished from sucrose
polyethers and glycerin-started polyethers, particularly by improved
flowability. However, when used in the production of polyurethane foams,
they do not possess all of the above-mentioned desirable characteristics
(see Comparative Examples 10 to 16 infra).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for the
preparation of polyether polyols in a commercially simple manner, which
polyols may be processed into rigid polyurethane foams.
It is another object of the invention to provide a process for the
preparation of polyether polyols which may be processed into rigid
polyurethane foams which have a small cell structure and good dimensional
stability both in moist heat and at cold temperatures.
It is a further object of the present invention to provide a process for
the preparation of polyether polyols which may be used to make a foam
mixture having good flow and curing properties.
These and other objects which will be apparent to those in the art are
achieved by alkoxylating a mixture of sucrose and formitol to produce a
polyether polyol having an average hydroxyl functionality of at least
three and a hydroxyl number of from 28 to 1000. The mixture which is
alkoxylated comprises (a) 20-80 weight % sucrose and (b) 80-20 weight %
formitol having an average hydroxyl functionality of at least three. The
formitol employed may be obtained by the reduction of mixtures of hydroxy
aldehydes and hydroxy ketones ("formose") which are obtained by the
auto-condensation of formaldehyde hydrate in the presence of metal
compound catalysts and co-catalysts which are capable of enediol
formation. (See e.g. German Offenlegungsschrift Nos. 2,639,083; 2,639,084;
2,714,084; 2,714,104; 2,721,186; 2,721,093; 2,732,077; 2,738,154;
2,738,512; 2,756,270; 2,808,228 and 2,831,659).
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a process for the production of polyether
polyols having an average hydroxyl functionality of at least 3, preferably
from 4 to 7, and a hydroxyl number of from 28 to 1000, preferably from 200
to 800, most preferably from 300 to 600. These polyether polyols are
prepared by alkoxylating a starting mixture of sucrose, a low molecular
weight polyol and optionally, water. This starting material is a mixture
comprising:
(a) from 20 to 80% by weight, preferably from 40 to 75% by weight sucrose
(based on the total weight of sucrose and formitol) and
(b) from 80 to 20% by weight, preferably from 60 to 25%, by weight of
formitol (based on the total weight of sucrose and formitol) having an
average hydroxyl functionality of at least 3, preferably from 3.3 to 5.7.
As mentioned above, the formitols which are suitable for the process of the
present invention may be obtained in known manner by the reduction
(generally by hydrogenation) of formose. These formitols are mixtures of
polyhydric alcohols which may be represented by the general formula:
C.sub.n H.sub.2n+2 O.sub.n
wherein n represents an integer .gtoreq.2 (traces of polyols wherein n>10
may be detected in the formitol) and has an average value of at least 3
(generally from 3 to 6, preferably from 3.3 to 5.7).
These formitols typically have compositions within the following ranges:
n=2: from 0.1 to 40%, by weight, preferably from 1 to 15%, by weight;
n=3: from 0.2 to 30%, by weight, preferably from 3 to 27%, by weight;
n=4: from 0.2 to 40%, by weight, preferably from 6 to 30%, by weight;
n=5: from 1.0 to 40%, by weight, preferably from 6 to 35%, by weight;
n=6: from 0.1 to 50%, by weight, preferably from 5 to 40%, by weight;
n=7: from 0.1 to 50%, by weight, preferably from 2 to 25% by weight.
In the process of the present invention, the starting material preferably
also contains water in a quantity of from 0.5 to 3 parts by weight (based
on 100 parts of sucrose and formitol).
According to the present invention, it is also preferred for the starting
material to contain from 2 to 20 parts by weight (based on 100 parts of
sucrose and formitol), of a low molecular weight polyhydric alcohol and/or
monoamine and/or polyamine.
The present invention also relates to the use of sucrose/formitol
polyalkylene glycol polyethers in making rigid polyurethane foams. These
polyethers are reacted with polyisocyanates according to known processes
to produce rigid polyurethane foams having a high surface hardness and
short in-mold times.
The process according to the present invention is preferably carried out by
mixing sucrose with formitol in the required weight ratios and then
suspending the mixture in an aromatic hydrocarbon solvent at room
temperature. The hydrocarbon solvent may be used in a quantity which
constitutes from 40 to 150%, preferably from 50 to 100% by weight of the
starting material. Under a nitrogen atmosphere, optionally a small
quantity (as compared with the quantity of the sugar/formitol mixture) of
a water-soluble, short-chain polyol, monoamine or polyamine, and/or a
small quantity of water and a small quantity of an alkali metal hydroxide
catalyst may be added in any sequence to this sucrose-formitol suspension
at temperatures of from 20.degree. to 110.degree. C., preferably from
50.degree. to 90.degree. C. The alkali metal hydroxide used is preferably
in the form of a concentrated aqueous lye. The thus-obtained stirrable,
pulpy mixture is then heated to the reaction temperature of from
85.degree. to 130.degree. C., preferably from 95.degree. to 115.degree.
C., and subsequently reacted with the alkylene oxide at pressures of from
0.3 to 4.0 bars, preferably from 0.5 to 2.5 bars.
The reaction temperature should be maintained at from 85.degree. to
130.degree. C., preferably from 95.degree. to 115.degree. C., by heating
or cooling the reaction mixture as required. When all of the alkylene
oxide has been added, the alkaline polymer may be neutralized with dilute
mineral acid. An antioxidant, such as 2,6-di-t-butyl-p-cresol may then be
added to the neutralized product. Water and hydrocarbon may be distilled
off under vacuum at a temperature of from about 50.degree. to 130.degree.
C., except for a small residual content. The salts which are separated by
this process may be removed by filtration.
In the process of the present invention, various aromatic hydrocarbon
solvents having a boiling point of from 80.degree. to 180.degree. C. may
be used. Solvents of this type include benzene, toluene, ethyl benzene,
xylenes and chlorobenzene. Toluene is the preferred solvent. The aromatic
hydrocarbons may also be used in the form of a mixture with aliphatic
solvents which have a boiling point of from 80.degree. to 180.degree. C.
The polyols, mono- and/or poly-amines which may optionally also be used in
the process of the present invention are preferably water-soluble
compounds melting below 100.degree. C. and generally have a molecular
weight of from 60 to 250. Examples of such compounds include: ethylene
glycol; propylene glycol; butane diol-1,4; diethylene glycol; dipropylene
glycol; trimethylol propane; glycerin; sorbitol; mannitol; mono-, di- and
tri-ethanolamine; mono-, di- and tri-isopropanolamine;
N-alkyl-alkanolamines, such as N-methyl-diethanolamine and
N-ethyl-diethanolamine; lower aliphatic mono- and di-alkylamines;
cycloalkylamines; aralkylamines; alkylene diamines, such as ethylene
diamine; and polyalkylene polyamines, such as diethylene triamine and
triethylene tetramine. Ethylene glycol, propylene glycol or amino-alcohols
are preferably used in the process according to the present invention.
Mixtures of two or more of these additives may also be used. Whether a
single additive or a mixture of additives is used, however, the total
quantity of the additives should be from 2 to 20%, preferably from 3 to
15% (based on the total weight of the sucrose/formitol).
The water content of the mixture of sucrose/formitol, additives and
catalysts according to the present invention should preferably be from 0.5
to 3%, most preferably from 0.6 to 2%, of the weight of the
sucrose/formitol mixture.
The alkylene oxide should preferably be reacted with the sucrose/formitol
suspension in the presence of an alkali metal hydroxide catalyst. Sodium
hydroxide and potassium hydroxide are preferred catalysts. In one
preferred embodiment, potassium hydroxide may be used as an approximately
50% aqueous solution in an amount such that the quantity of potassium
hydroxide is from 1.0 to 5.0% (preferably from 2.0 to 3.0%) of the weight
of the sucrose/formitol suspension.
In the process according to the present invention, ethylene oxide,
propylene oxide and/or 1,2-butylene oxide are the preferred alkylene
oxides. This alkoxylation reaction may be carried out using the mentioned
alkylene oxides singly or as mixtures. It is also possible in the process
of the present invention to use successively different alkylene oxides in
the reaction mixture to prepare "block copolyethers".
The reaction temperature may be varied over a comparatively wide range,
although the process is generally carried out at from 85.degree. to
130.degree. C., preferably from 95.degree. to 115.degree. C. The alkylene
oxides should be reacted with the sucrose/formitol mixture at elevated
pressure (generally from 0.3 to 4.0 bars, preferably from 0.5 to 2.5
bars).
In preparing polyethers according to the present invention, the quantity of
alkylene oxide used should generally be selected so that each starter
molecule is reacted, on average, with from about 4 to 20 (preferably from
about 8 to 15) molecules of the alkylene oxide. The thus-obtained
polyethers generally have hydroxyl numbers of from 200 to 800, preferably
from 300 to 600.
The polyether polyols according to the present invention surprisingly
produce outstanding mechanical characteristics in polyurethane plastics
(particularly surface hardness for rigid foams). Highly functional
polyethers may only be prepared from sugar/polyol mixtures (if at all) by
means of conventional processes, however, at considerable technical
expense. Polyethers prepared by the prior art processes are generally
highly viscous and brown colored due to the by-product content.
In contrast, the polyethers prepared according to the present invention
range from clear to yellowish, and may be watery or viscous. According to
the hydroxyl number and additive content, the viscosity of the product may
be from 300 to 36,000 mPas/25.degree. C. (at low hydroxyl numbers of
approximately 350) or from 1000 to 1,000,000 mPas/25.degree. C. (at higher
hydroxyl numbers approximating 550). By varying the hydroxyl number and
the quantity of additives, (and to a lesser extent by varying the small
amount of water), products may be obtained which have a viscosity adapted
to the intended application.
The sucrose/formitol polyethers obtained according to the present invention
are particularly valuable starting materials for the production of rigid
polyurethane foams. Such foams may be made in accordance with known
processes by reacting an isocyanate (preferably an aromatic
polyisocyanate) in the presence of conventional auxiliary agents and
additives. The thus-obtained foams possess a combination of physical
properties which are particularly advantageous.
Polyisocyanates which are suitable for the production of polyurethanes
according to the present invention, optional higher molecular weight
and/or low molecular weight compounds, optional activators, stabilizers,
blowing agents and other known additives may be found in the
above-mentioned references and also in German Offenlegungsschrift Nos.
2,738,513; 2,738,532 and 2,738,533.
Having thus described our invention, the following Examples are given by
way of illustration. Unless otherwise indicated all amounts are given in
part by weight or percent by weight.
In carrying out the alkoxylation reactions of the following Examples, an
autoclave which was equipped with a heating and cooling device, a stirring
apparatus, an apparatus to expel the air by means of nitrogen gas (e.g. a
vacuum connection and a nitrogen supply) and a device to meter the
alkylene oxide was used.
EXAMPLES
EXAMPLE 1
640 g of a formitol having composition:
dihydric alcohols: 6.88%, by weight
trihydric alcohols: 23.55%, by weight
tetrahydric alcohols: 22.9%, by weight
pentahydric alcohols: 16.6%, by weight
hexahydric alcohols: 18.08%, by weight
heptahydric alcohols and higher polyhydric alcohols: 11.99%, by weight
(average hydroxyl functionality: 4.01)
and 1208 g of sucrose were introduced into 600 g of toluene at room
temperature.
By twice flushing the reaction vessel with nitrogen, the atmospheric oxygen
was removed. After heating the sucrose/formitol suspension to 80.degree.
C., 67 g of 50% aqueous potash lye were added. The mixture was then
re-heated. At from 100.degree. to 110.degree. C., 4139 g of propylene
oxide were gradually metered into the stirrable mixture at a pressure of
from 0.4 to 0.6 bars. The reaction temperature was maintained by cooling
or heating as required. After all the propylene oxide has been added, the
mixture was stirred for another 3 hours at from 100.degree. to 110.degree.
C. After adding 600 g of water and 201 g of 12.6% aqueous sulphuric acid,
the alcoholic polymer was neutralized. After adding filtration aids
(cellulose powder and synthetic magnesium silicate) and an antioxidant
(2,6-di-t-butyl-p-cresol) the water was then distilled off under vacuum at
from 70.degree. to 90.degree. C. At a water content of 0.9%, the separated
salts and the filtration aids were filtered off. In order completely to
remove the water, the filtrate was then distilled under vacuum at from
100.degree. to 105.degree. C.
The product which was obtained had the following properties:
Hydroxyl number (mg KOH/g): 449
pH: 8.7
Water content (%): 0.1
Viscosity at 25.degree. C. (mPas): 27,400
Average hydroxyl functionality: 5.0
The hydroxyl numbers which are stated in the Examples were obtained by
acylating the polyether with excess phthalic acid anhydride and pyridine
in the usual manner.
In determining the pH, a mixture of methanol and water in a volume ratio of
9:1 was used as the solvent. For the pH measurement, 10 ml of the
polyether and 100 ml of the solvent were used. The pH was measured by
means of a single-rod glass electrode.
EXAMPLE 2
A polyether was prepared from the following materials according to the
process described in Example 1:
764 g of the formitol from Example 1
960.3 g of sucrose
600 g of toluene
68.4 g of 50% aqueous potash lye
4276 g of propylene oxide
The product which was obtained had the following properties:
Hydroxyl number (mg KOH/g): 441
pH: 8.1
Water content (%): 0.08
Viscosity at 25.degree. C. (mPas): 14,800
Average hydroxyl functionality: 4.7
EXAMPLE 3
480 g of formitol from Example 1, 1208 g of sucrose, 179 g of propylene
glycol and 600 g of toluene were introduced into the reaction vessel at
room temperature. By twice flushing the reaction vessel with nitrogen, the
atmospheric oxygen was removed. After heating to 80.degree. C., 65.3 g of
50% aqueous potash lye were added. The stirrable mixture was heated to
100.degree. C. and 4133 g of propylene oxide were gradually metered in at
a pressure of from 0.4 to 0.6 bars and a temperature of from 100.degree.
to 110.degree. C. The course of the reaction and subsequent working-up of
the reaction mixture were substantially the same as in Example 1.
The product which was obtained had the following properties:
Hydroxyl number (mg KOH/g): 416
pH: 9.3
Water content (%): 0.05
Viscosity at 25.degree. C. (mPas): 16,100
Average hydroxyl functionality: 4.5
EXAMPLE 4
A polyether was prepared from the materials described below according to
the process as described in Example 1.
676 g of a formitol having the composition:
dihydric alcohols: 37%, by weight
trihydric alcohols: 17%, by weight
tetrahydric alcohols: 16%, by weight
pentahydric alcohols: 12%, by weight
hexahydric alcohols: 13%, by weight
heptahydric alcohols and higher polyhydric alcohols: 5%, by weight
(average hydroxyl functionality: 3),
1208 g of sucrose, 700 g of toluene, 60 g of 50% aqueous potash lye and
4124 g of propylene oxide.
The product which was obtained had the following properties:
Hydroxyl number (mg KOH/g): 425
pH: 7.2
Water content (%): 0.03
Viscosity at 25.degree. C. (mPas): 11,400
Average hydroxyl functionality: 4.3
In Examples 5 to 19, in addition to the polyethers according to the present
invention which were started on sucrose/formitol, the following
conventional polyethers were used:
Polyether A
Addition product of propylene oxide to a formitol of the following
composition:
dihydric alcohols: 1%, by weight
trihydric alcohols: 4%, by weight
tetrahydric alcohols: 8%, by weight
pentahydric alcohols: 34%, by weight
hexahydric alcohols: 38%, by weight
heptahydric and higher polyhydric alcohols: 15%, by weight
(average hydroxyl functionality: 5.2).
Propoxylation took place according to the process described in German
Offenlegungsschrift No. 2,639,083. Hydroxyl number of the polyether: 550.
Polyether B
Addition product of propylene oxide to a mixture of 1881 g of sucrose, 1900
g of 1,2-propylene glycol and 36 g of water. Hydroxyl number: 370; average
hydroxyl functionality: 3.
Propoxylation of the above starting mixture took place according to the
process described in U.S. Pat. No. 3,941,769.
Polyether C
Addition product of propylene oxide to a formitol of the following
composition:
dihydric alcohols: 36.6%, by weight
trihydric alcohols: 16.4%, by weight
tetrahydric alcohols: 16.2%, by weight
pentahydric alcohols: 12.6%, by weight
hexahydric alcohols: 12.8%, by weight
heptahydric and higher polyhydric alcohols: 5.4%, by weight
(average hydroxyl functionality: 3)
Propoxylation took place according to the process described in German
Offenlegungsschrift No. 2,639,083.
Hydroxyl number of the polyether: 405.
Average hydroxyl functionality: 3.
Polyether D
Addition product of propylene oxide to a mixture of sucrose and glycerine,
prepared according to the process described in U.S. Pat. No. 3,941,769.
Hydroxyl number: 400.
Average hydroxyl functionality: 4.2.
Polyether E
Analogous to polyether D; started on a mixture of sucrose and glycerin.
Hydroxyl number: 380.
Average hydroxyl functionality: 4.5.
Polyether F
Addition product of propylene oxide to a mixture of sucrose and
1,2-propylene glycol; prepared by a process analogous to that used in
making polyether D.
Hydroxyl number: 430.
Average hydroxyl functionality: 4.1
Polyether G
Analogous to polyether D, started on a mixture of sucrose and glycerin.
Hydroxyl number: 480.
Average hydroxyl functionality: 5.1.
Polyether H
Propoxylated diethylene triamine; hyroxyl number: 440.
Polyether I
Addition product of propylene oxide to a mixture of sorbitol and
1,2-propylene glycol, prepared by a process analogous to that of Example 1
in German Offenlegungsschrift No. 2,519,449.
Hydroxyl number: 450
Average hydroxyl functionality: 2.8.
Polyether J
Propoxylated 2,4-toluylene diamine; hydroxyl number: 370.
EXAMPLE 5
95 g of the polyether polyol of Example 4, 1.5 g of water, 2 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 3 g of
dimethyl cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was thoroughly mixed with 129 g of crude
4,4'-diisocyanatodiphenylmethane (obtained by phosgenating a commercial
aniline/formaldehyde condensate and having an NCO-content of 31%). The
mixture was then charged into one of the molds described below.
1. Paper (test-) packet of dimensions 20.times.20.times.14 cm to determine
the starting and setting times, the free bulk density and also the surface
brittleness when the foamed plastic had cured.
2. A panel mold of dimensions 22.times.22.times.6 cm, in which sandwich
panels with 1 mm thick sheet steel covering layers were foamed to
determine the minimum in-mold time. The term "minimum in-mold time"
designates the time during which the panel must remain in a previously
heated mold so that it does not have any thickness swellings 30 minutes
after being removed from the mold. From the measured data a collective
determination of the essential properties of such foams
(surface-brittleness, adhesiveness and "minimum in-mold-time"), made of
the polyether polyol and optionally the polyether polyol combination was
made. The results obtained are presented in Table 1 below together with
those from Examples 6 to 9 (according to the present invention) and
Comparative Examples 10 to 19. The surface brittleness was determined
according to the following codes:
1=surface does not become brittle
2=surface only becomes brittle for a period of 15 minutes
3=the surface becomes brittle for a period of 15-60 minutes
4=the surface remains brittle for more than 60 minutes
EXAMPLE 6
95 g of the polyether of Example 1, 1.5 g of water, 2 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293). 3.4 g
of dimethyl cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 141 g of crude
4,4'-diisocyanatodiphenylmethane under the conditions indicated in Example
5. The resulting foams were tested and judged in a manner analogous to
that of Example 5.
EXAMPLE 7
95 g of the polyether of Example 2, 1.5 g of water, 2 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 3.4 g
of dimethyl cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 139 g of crude
4,4'-diisocyanatodiphenylmethane under the same conditions as Example 5.
The resulting foams are tested and judged analogously to Example 5.
EXAMPLE 8
95 g of the polyether of Example 3, 1.5 g of water, 2 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 2.8 g
of dimethyl cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as a
blowing agent) were mixed.
This mixture was foamed with 131 g of a crude
4,4'-diisocyanatodiphenylmethane under the same conditions used in Example
5. The resulting foams were tested and judged analogously to Example 5.
EXAMPLE 9
95 g of the polyether polyol of Example 4, 2.4 g of water, 2.0 g of foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 2.6 g
of dimethyl cyclohexylamine and 35 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 142 g of crude
4,4'-diisocyanatodiphenylmethane under the same conditions as were used in
Example 5. The resulting foams were tested and judged analogously to
Example 5.
EXAMPLE 10 (Comparative Example)
47.5 g of polyether A, 47.5 g of polyether B, 1.5 g of water, 2 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 3 g of
dimethyl cyclohexylamine and 38 g of fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 139 g of crude
4,4'-diisocyanatodiphenylmethane under the conditions used in Example 5.
The resulting foams were tested and judged analogously to Example 5. The
physical properties of this foam were poorer than those made with the
polyether polyols according to the present invention as can be seen from
Table 1. The greater surface brittleness of the foam produced is
particularly disadvantageous.
EXAMPLE 11 (Comparative Example)
47.5 g of polyether polyol A, 47.5 g of polyether polyol B, 1.5 g of water,
2 g of a foam stabilizer (according to German Offenlegungsschrift No.
2,029,293), 0.5 g of N, N, N', N", N"-pentamethyl diethylene triamine, 2 g
of dimethyl cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 139 g of crude
4,4'-diisocyanatodiphenylmethane under the same conditions as were used in
Example 5. The resulting foams were tested and judged analogously to
Example 5. The inferiority of this foam (in comparison with foam made from
polyether polyols according to the present invention) may be seen from the
data in Table 1. The coarser cell structure of this product is also
disadvantageous.
EXAMPLE 12 (Comparative Example)
47.5 g of polyether A, 47.5 g of polyether C, 1.5 g of water, 2 g of foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 2.9 g
of dimethyl cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 142 g of crude
4,4'-diisocyanatodiphenylmethane under the same conditions used in Example
5. The resulting foams were tested and judged analogously to Example 5.
The inferiority of this product with respect to foams made with polyether
polyols of the present invention may be appreciated by examination of
Table 1. The coarse cell structure of this product is disadvantageous.
EXAMPLE 13 (Comparative Example)
47.5 g of polyether A, 47.5 g of polyether C, 2 g of water, 2 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 2.6 g
of dimethyl cyclohexylamine and 35 g of a fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 142 g of crude
4,4'-diioscyanatodiphenylmethane under the conditions used in Example 5.
The resulting foams were tested and judged analogously to Example 5. The
inferiority of this product as compared to foams made with polyether
polyols of the present invention may be seen from the data of Table 1.
The greater surface brittleness of the resultant foam is particularly
disadvantageous.
EXAMPLE 14 (Comparative Example)
95 g of polyether D, 1.5 g of a foam stabilizer (according to German
Offenlegungsschrift No. 2,029,293), 1.4 g of water, 0.5 g of
N,N,N',N",N"-pentamethyl diethylene triamine, 1.5 g of dimethyl
cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the blowing
agent) were mixed.
This mixture was foamed with 130 g of crude
4,4'-diisocyanatodiphenylmethane under the same conditions used in Example
5. The resulting foams were tested and judged analogously to Example 5.
The inferiority of this product as compared to foams made from the
polyether polyols of the present invention may be seen from Table 1. The
longer in-mold time is particularly disadvantageous.
EXAMPLE 15 (Comparative Example)
95 g of polyether E, 2.1 g of water, 1.5 g of a foam stabilizer (according
to German Offenlegungsschrift No. 2,029,293), 3.5 g of dimethyl
cyclohexylamine and 38 g of a fluorochlorohydrocarbon (as the blowing
agent) were mixed.
This mixture was foamed with 140 g of crude
4,4'-diisocyanatodiphenylmethane under the same conditions used in Example
5. The resulting foams were tested and judged analogously to Example 5.
The inferiority of this foam as compared to foams made with the polyether
polyols of the present invention may be seen from the details presented in
Table 1. The high amine quantity and also the longer in-mold time of this
foam are particularly disadvantageous.
EXAMPLE 16 (Comparative Example)
95 g of polyether F, 2.1 g of water, 1.9 g of a foam stabilizer (according
to German Offenlegungsschrift No. 2,029,293), 0.7 g of N, N, N', N",
N"-pentamethyl diethylene triamine and 36 g of a fluorochlorohydrocarbon
(as the blowing agent) were mixed.
This mixture was foamed with 150 g of crude
4,4'-diisocyanatodiphenylmethane as previously described. The resulting
foams were tested and judged analogously to Example 5. The inferiority of
the product foam as compared to foams made with the polyether polyols
according to the present invention may be seen from Table 1. The surface
of the foamed plastics which is brittle for a longer time and also the
poor adhesion to the covering layers are particularly disadvantageous.
EXAMPLE 17 (Comparative Example)
75 g of polyether G, 20 g of polyether H, 1.5 g of water, 1.5 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 0.6 g
of dimethyl ethanolamine, 0.9 g of N,N,N',N",N"-pentamethyl diethylene
triamine, 1.2 g of dimethyl cyclohexylamine and 38 g of
fluorochlorohydrocarbon (as the blowing agent) were mixed.
This mixture was foamed with 133 g of crude
4,4'-diisocyanatodiphenylmethane under the above described conditions. The
resulting foams were tested and judged analogously to Example 5. The
inferiority of this foam as compared to foams made with the polyether
polyols of the present invention may be seen from the details of Table 1.
The surface which was brittle for a longer time and the long in-mold time
are particularly disadvantageous.
EXAMPLE 18 (Comparative Example)
75 g of polyether I, 20 g of polyether J, 2 g of water, 1.5 g of a foam
stabilizer (according to German Offenlegungsschrift No. 2,029,293), 2 g of
dimethyl cyclohexylamine and 35 g of fluorochlorohydrocarbon (as the
blowing agent) were mixed.
This mixture was foamed with 140 g of crude
4,4'-diisocyanatodiphenylmethane under the conditions described above. The
resulting foams were tested and judged analogously to Example 5. The
inferiority of of t | | |
