Note: Descriptions are shown in the official language in which they were submitted.
591:~
.
PROCESS FOR THE PRODUGTION OF CGLD SETTING
FOAMS WHIC~ CONTAIN URETh NE GROUPS_
BACKGROU~D OF THE INVENTION
Foams which contain urethane groups are widely
used, for ~xample, in the field of insulation for the
manufacture of structural elements and for upholstery
I ~
: purposes. It is known that cold set-ting foams which con-
tain urethane groups can be produced from higher molecular
welght polyols such as hydroxyl polyethers, special poly-
isocyanates, water and/or other blowing agents,
: optionally in the presence of catalysts and other
auxiliary agents. The higher molecular weight polyols
~ used are frequently polyethers, for example, having
.~ 15 molecular weights of 400 - 10,000, which contain at least
two hydroxyl groups and in which at least about 10~ of
'~'' ~
LeA 17~468 ~
S~
the hydroxyl groups are primary hydroxyl groupsO These
polyethers are used, for example, in combination with special
polyisocyanates. The special isocyanates used may be, for
example, a mixture of diphenylmethane diisocyanates and
polyphenyl-polymethylene polyisocyanates.
The previously known cold setting foams based on
polyphenyl-polymethylene polyisocyanates, for example, those
described in German Offenlegungsschrift 2J425/657~ (see
particularly Examples 1-5) have a serious disadvantage, which
10 is particularly disturbing when the foams are produced inside
molds. Thus, even when the reaction mixture has been inside
the mold for abou~ 10 minutes, the foams formed during this time
are still irreversibly deformable. Although this tendency
to deformation can be overcome by storage of the reaction
15 mixture for about 24 h~urs or by subsequent heating of the foams
after their removal from the mold, for about thirty minutes at
120C, it is always a disadvantageous characteristic.
Furthermore, molding times of less than five minutes cannot
generally be achieved.
An improved process for the production of cold setting,
flexible foams which contain urethane groups has now been
found. This process reduces or substantially obviates the
disadvantages described above and is based on the use of a
certain mixture of diphenylmethane diisocyanates and oligomer
~5 polyphenyl-polymethylene polyisocyanates.
DESCRIPTION OF THE INVENTION
The present invention thus relates to a process
for the production of molded cold setting, flexible foams,
having a cellular structure on the sur'ace thereof, and the
LeA 17,468 -2-
B
55~
foams produced thereby, which foams contain urethane groups by
the reaction in a mold of polyethers with amolecular weight
of 400 to 10,000 which contains at least two hydroxyl groups
and in which at least 10% by weight of the hydroxyl groups are
primary hydroxyl groups, mixed with a mixture of diphenyl-
methane diisocyanates and oligomeric polyphenyl-polymethylene
polyisocyanates in the presence of blowing agents and in the
presence of one or more amine catalysts and optionally other
catalysts and foaming aids, characterized in that the mixture
10 of diphenylmethane diisocyanates and polyphenyl-polymethylene
polyisocyanates, which is substantially free of carbodiimide
groups and contains from 60 to 90% by weight, preferably 65-
80% by weight of 4,4'-diphenylmethane diisocyanate and from 3
to 30% by weight, preferably 10~30% by weight of 2,4'-diphenyl-
15 methane diisocyanate and wherein the reaction is carried outin the absence of foam stabilizers and wherein the amine
catalysts are selected from the group consisting of diaza-
bicyclo-2,2,2-octane, 2,2'-dimethyl-aminodiethyl ether, tetra-
methyl ethylene diamine, and N-methyl morpholine. The amount
20 of polyphenyl-polymethylene polyisocyanates in this isocyanate
mixture is from 0-37% by weight, preferably from 10-20% by
weight.
The invention has surprisingly been found to show the
following practical advantages:
(1) Due to the very rapid hardening of these foam
systems, molding times of between 3 minutes and less than 1
minute can be obtained.
(2) The rapid hardening substantially reduces the
tendency of the foam to deformation, so that any intermediate
30 storage time can be considerably reduced. Reheating of the
molded articles after removal from the mold is no longer
necessary. The foams can be packaged a-fter 10 minutes without
risk of defo~mation.
LeA 17,468 -3-
~59~
The polyisocyanate mixture itself is known in the
art. In addition to the polyisocyanate mixture used accord-
ing to the invention, other isocyanates may be used as
starting materials in quantities of up to 20~ by weight,
based on the quantity of polyisocyanate mixture according to
the invention. These additional, optional, isocyanates
include aliphatic, cycloaliphatic and other aromatic and
heterocyclic polyisocyanates such as those described, for
example, by W. Siefken in Jus~us Liebigs Annalen der Chemie
562, pages 75 to 136. Specific examples include ethylene
diisocyanate; 1,4-tetramethylene diisocyanate; 1,6-hexa-
methylene diisocyanate; 1,12-dodecane di}socyanate;
cyclobutane-1,3-diisocyanate; cyclohexane 1,3- and 1,4-
: diisocyanate and mixtures of these isomers; l-isocyanato-
3,3,5-trimethyl-5-isocyanatomethy~-cyclohexane as described
in German Auslegeschrift 1,202,785 and U. S. Patent
; ~ : 3,401,190; 2,4- and 2,6-hexahydrotolylene diisocyanate arld
mixtures of these isomers; hexahydro-1,3- and/or -1,4-
phenylene diisocyanate; perhydro-2,4'- and/or -4,4'-
diphenylmethane diiæocyanate; 1,3- and 1,4-phenylene
diisocyanate; 2,4 and 2,6-tolyene diisocyanate and mixtures
of these isomers naphthylene-1,5-diisocyanate; triphenyl-
methane-4,4',4"-triisocyanate; m- and p-isocyanatophenyl-~
sulphonyl isocyanate as described in U. S. Patent 3,454,606;
perchlorinated aryl polyisocyanates as described, for example,
in German Auslegeschrift 1,157,601 and U. S. Patent
3,277,138; polyisocyanates having carbodiimide groups as
de~cribed in German Patent 1,092,007 and U. S. Patent
3,152,162l the diisocyanates described in U. S. Patent
: LeA 17,468 -4_
3,492,330; polyisocyanates having allophanate groups as
described, e.g., in British Patent 994,890; Belgian Patent
761,626 and published Dutch Patent Application 7,102,524;
polyisocyanates having isocyanurate groups as described, for
example, in U. S. Patent 3,001,973, German Patents 1,022,789,
1,222,067 and 1,027,394, and in German Offenlegungsschriften
1,929,034 and 2,004,048; polyisocyanates having urethane
groups, e.g., as described in Belgian Patent 752,261 and in
U. S. Patent 3,394,164; polyisocyanates having acylated urea
groups, as described in German Patent 1,230,778; polyisocyan-
ates having biuret groups, e.g., as described in ~erman
Patent 1,101,394, U. S. Patents 3,124,605 and 3,201,372,
and in British Patent 889,050; polyisocyanates prepared by
te~omerization reactions, as described, for example, in U. S.
Patent 3,654,106; polyisocyanates with ester groups, e.g ,
such as those described in British Patents 965,474 and
1,072,956, U. S. Patent 3,567,763 and German Patent 1,231,688,
reacti.on products of the above-mentioned isocyanates with
acetals, as described in German Patent 1,072,385; and poly-
isocyanates containing polymeric fatty acid groups, as
described in U. S. Patent Specification 3,455,883.
~ The distillation residues obtained from the
commercial production of isocyanates and still containing
isocyanate groups may also be used, if desired as solutions
in one or more o~ the above-mentioned polyisocyanates. Any
mixtures of the above-mentioned polyisocyanates may, of
course, be used.
LeA 1~1,468 -5_
r~
Monofunctional isocyanates, such as propyl iso_yan-
ate, cyclohexyl isocyanate, phenyl isocyanate, tolyl
isocyanate and p-chlorophenyl isocyanate may also be inc:Luded.
Polyethers containing at least two hydroxyl groups
and generally having a molecular weight of from 400 to 10,000
are also used as a starting component according to the inven-
tion. Particularly preferred polyethers containing from
2 - 8, preferably 2 - 4 hydroxyl groups and especially those
with a molecular weight of from 800 to 10,000, and most
preferably 1,000 to 6,000. At least 10%, by weight, of the
nydroxyl groups in these polyethers are primary hydroxyl
groups.
These polyethers are known in the art and may be
prepared, for example, by the polymerization of epoxides,
such as ethylene oxide, propylene oxide, butylene oxide,
tetrahydrofuran, styrene oxide or epichlorohydrin, alone,
e.g., in the presence of boron trifluoride, or by addition of
these epoxides, either as mixtures or successively, to start-
ing components with reactive hydrogen atoms. Suitable start-
ing components include water, alcohols, ammonia:or amines.
Suitable examples include ethylene glycol; propylene glycol-
(1,3) or -(1,2); trimethylolpropane; glycerol, 4,~'-dihydroxy-
diphenylpropane; anniline; ethanolamine; ethylenediamine;
and the like. In these polyethers, the pr.imary hydroxyl ~end)
groups are preferably formed by the reaction of ethylene oxide.
Sucrose polyethers may also be used according to the inven-
tion, for example, those described in German Auslegeschriften
1,176,358 and 1,064,938. Polyethers modified by vinyl
: LeA 17,468 t - 6-
:; ~ ,.
9/~
polymers, for example, the compounds obtained by the poly-
merization of styrene and acrylonitrile in the presence of
polyethers, as described in U. S. Patents 3,383,351; 3,3~4,273;
3,523,093 and 3,110,695 and German Patent 1,152,536 and
polybutadienes which contain hydroxyl groups are also suitable.
The starting components which may be used according
to the invention in addition to -the polyethers may al50
include in quantities of up to 50~, by weight, based on the
polyethers, hydroxyl polyesters, hydroxyl polyethers which
are substantially free from primary hydroxyl grou~s, hydroxyl
polythioethers, hydroxyl polyacetals, hydroxyl polycarbonates
and hydroxyl polyester amides, all of which are known in the
art for the production of both homoqeneous and cellular poly-
urethanes. These hydroxyl polymers contain at least two
hydroxyl groups, generally 2 to 8, preferably 2 to 4 hydroxyl
groups and they generally have molecular weights of from 400
to 10,000, pre~erably 800 to 10,000 and most preferably 1,000
to 6,000.
Suitable polyesters with hydroxyl groups include,
for example, the reaction products of polyhydric, preferably
dihydric alcohols to which trihydric alcohols, may be added
and polybasic, preferably dibasic carboxylic acids. Instead
of rree polycarboxylic acids, the corresponding polycarboxylic
acid esters of lower alcohols or mixtures thereof may be used
for preparing the polyesters. The polycarboxylic acids may
be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and
they may be substituted, e.g., by halogen atoms and/or
unsaturated. The following are mentioned as examples of
LeA 17,468 -7-
~s~
useful acidic materials: succinic acid, adipic acid, suberic
acid, azelaic acid, sebacic acid, phthalic acid, isophthalic
acid, trimellitic acid, phthalic acid anhydride, tetrahyclro-
phthalic acid anhydride; hexahydrophthalic acid anhydride;
tetrachlorophthalic acid anhydride; endomethylene tetra-
hydrophthalic acid anhydride; glutaric acid anhydride; male:ic
acid, maleic acid anhydride, fumaric acid, dimeric and trimeric
fatty acids such as oleic acid which may he mixed with mono-
meric fatty acids; dimethyl terephthalate and terephthalic
acid-bis-glycol esters, and the like. The following are~
examples of suitable polyvalent alcohols: ethylene glycol,
propylene glycol (1,2~ and -~1,3), butylene glycol-(1,4) and
-(2,3), hexanediol-(1,6), octanediol-(1,8), neopentylglycol,
cyclohexanedimethanol (1,4-bis-hydroxymethylcyclohexane),
2-methyl-1,3-propanediol, glycerol, trimethylolpropane,
hexanetriol-(1,2l6), butane~riol-(1,2,4), trimethylolethane,
pentaerythritol, quinitol, mannitol and sorbitol, methyl-
glycoside, diethylene glycol, triethylene glycol, tetra-
ethylene glycol, polyethylene glycols, dipropylene glycol,
polypropylene glycols, dibutylene glycol, poly~utyIene
glycols, and the like. The polyesters may also contain a
proportion of carboxyl end groups. Polyesters of lactones
such as ~-caprolactone or hydroxycarboxylic acids such as
(~-hydroxycaproic acid may also be used.
The optional hydroxyl polyethers used according
to the invention which have at least 2, generally 2 to 8 and
preferably 2 to 3 hydroxyl groups (which are not primary
hydroxyl groups) are also known and are prepared, for example,
by polymerizatlon of epoxides such as ethylene oxides,
v
Le~ 17,468 -8-
s' : -
,
~lS,~
propylene oxide, butylene oxide, tetrahydrofuran, styrene
oxide or epichlorohydrin, either alone, e.g., in the presence
of boron trifluoride, or by addition of these epoxides, either
as mixtures ox succes~ively, to starting components having
reactive hydrogen atoms, such as water, alcohols, ammonia or
amines. Suitable starting components include ethylene glycol,
propylene glycol-(1,3) or -(1,2), trimethylolpropane, 4,4'-
dihydroxy diphenylpropane, aniline, ethanolamine, ethylene
diamine and the like. Sucrose polyethers may also be used
accord~ng to the invention, e.g., those described in German
Auslegeschriften 1,176,358 and l,064,938. All these poly-
ethers are substantially free from primary hydroxyl groups.
Particularly to be mentioned among the polythio-
ethers are the condensation products obtained by reacting
thiodiglycol on its own and/or with other glycols, dicarboxylic
acids, formaldehyde, aminocarboxylic acids or arnino alcohols.
The products obtained are polythio mixed ethers, polythio
ether esters or polythio ether ester amides, depending on the
cocomponents.
Suitable polyacetals include, for example, the com-
pounds which can be prepared from glycols such as diethylene
glycol, triethylene glycol, 4,4'-dioxethoxydiphenyl dimethyl-
methane, hexanediol and formaldehyde. Suitable polyacetals
for the purpose of the invention may also be prepared by the
polymerization of cyclic acetals.
The polycarbonates with hydroxyl groups used may be
of the kind known in the art. Such as, for examples, those
Le~ 17,468 -9-
1 ~ ,'
9~aD
which can be prepared by the reaction of diols such as
propanediol-(1,3), butanediol-(1,4) and/or hexanediol-(l t 6),
diethylene glycol, triethylene glycol or tetraethylene glycol
with diarylcarbonates, e.g., with diphenylcarbonate or
phosgene.
Suitable polyester amides and polyamides include,
for example~ the predominantly linear condensates prepared
from polyvalent saturated and unsaturatecl carboxylic acids or
their anhydrides and polyvalent saturated and unsaturated
amino alcohols, diamines, polyamines and mixtures thereof.
Polyhydroxyl compounds already con~aining urethane
or urea groups and modified or unmodified natural polyols 5uch
as castor oil, carbohydrates or starch may also be used.
Addition products of al]cylene oxides and phenol formaldehyde
resins or of alkylene oxides and urea formaldehyde resins are
also suitable for he purpose of the invention.
Representatives of the many compounds which may be
used according to the invention are known and have heen
described, for example, in High Polymers, Volume XVI, "Poly-
urethanes, Chemistry and Technology" by Saunders Frisch,
Interscience Publishers, New York, London, Volume I, 1962,
pages 32 - 42 and pages 44 - 45 and Volume II 7 1964, pages
5 - 6 and 198 - 199 and in Kunststof~-Handbuch, Volume VII,
Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, 1966, e.g., on
pages 45 to 71.
Mixtures of the above-mentioned compounds which
contain at least two hydrogen atoms capable of react:ing with
LeA 17,468 -10-
9~
isocyanates and have a molecular weight of from 400 to 1()l00
may, of course, also be used, for example, mixtures of poly-
ethers and polyesters.
The starting componnts used according to the inven-
tion may also include compounds with a molecular weight of
from 32 to 400 which have at least two hydrogen a-toms capable
of reacting with isocyanates in amounts of up to 50%, by
weight, based on the weight of primary hydroxyl group con-
taining polyethers. These materials include compounds con-
taining hydroxyl groups and/or amino groups and/or thiol
groups and/or carboxyl groups, preferably hydroxyl groups
and/or amino groups, and they serve as chain-lengthening agents
or cross-lillklng agenks. They generally have from 2 to 8
hydrogen atoms capable of reacting with isocyanates, pre-
ferab1y 2 or 3 such hydrogen atoms. ~he following are examples
of such compounds: ethylene glycol, propylene glycol-(1,2)
and (1,3), butylene glycol-(1,4) and -(2,3), pentanediol-
(1,5), hexanediol-(1,6), octanediol-(1,8), neopentyl glycol,
1,4-bis-hydroxymethyl-cyclohexane, 2-methyl-1,3-propanediol,
glycerol, trimethylol propane, hexanetriol-(1,2,6), trimethylol-
ethane, pentaerythritol, quinitol, mannitol and sorbitol,
diethylene glycol, triethylene glycol, tetraethylene glycol r
polyethylene glycols with a molecular weight of up to 400,
dipropylene glycol, polypropylene glycols with a molecular
weight o up to 400, dibutylene glycol, polybutylene glycols
with a molecular weight of up to 400, 4~4'-dihydroxy-diphenyl
propane, dihydroxymethyl-hydroquinone, ethanolamine, diethanol
amine, triethanolamine, 3 aminopropanol, ethylene diamine,
'
LeA 17,468
;'
: `
~L5~
1,3-diaminopropane, l-mercapto 3-aminopropane, 4-hydroxy-
phthalic acid, 4-aminoph-thalic acid, succinic acid, adipic
acid, hydrazine, N,N-dimethylhydrazine, 4,4'-diaminodiphenyl-
methane, tolylenediamine, methylene-bis-chloraniline, methylene-
bis-anthranilic acid ester, diaminobenzoic acid esters, the
isomeric chlorophenylene diamines, and the like.
In this case, again there may be used mixtures of
various compounds having a molecular weight of from 32 to
400 and containing at least two hydrogen atoms capable of
reacting with isocyanates.
According to the invention, polyhydroxyl compounds
in which high molecular weight polyadducts or polycondensates
are finely dispersed or dissolved may also be used in
quantities of up to 50% by weight based on the primary hydroxyl
lS group containing polyether. These modified polyhydroxyl com-
pounds are obtained when polyaddition reactions, e.g.,
reactions between polyisocyanates and amino functional com-
pounds, or polycondensation reaotions, e.g., between formalde-
hyde and p,henols and/or amines, are carried out ln situ in any
of the above-mentioned hydroxyl compounds. Processes of this
kind have been described, for example, in German Auslege-
schriften 1,168,075 and 1,260,142 and in German Offenlegung-
sschriften 2,324,134: 2,423,984; 2,512,385; 2,513/185;
2,550,796; 2,550,797; 2,550,833 and 2,550,862. Alternatively,
these modified polyhydroxyl compounds may be obtained according
to U. S. Patent 3,869,413 or German Offenlegungsschrift
2,550,860 by mixing a previously prepared aqueous polymer
dispersion with a polyhydroxyl compound and then removing
the water from the mixture.
LeA 17,468 -12
Accorcling to the invention, water and/or readily
volatile organic substances are used as blowing agents.
Suitable organic blowing agents include, for example, acetone,
ethyl acetate and halogen substituted alkanes such as
methylene chloride, chloroform, ethylidene chloride, vinylidene
chloride, monofluorotrichlorome-thane r chlorodifluoromethane,
and dichlorodifluoromethane as well as butane, hexane,
heptane and diethyl ether. The effect of a blowing agent can
also be obtained by the addition of compounds which decompose
at temperatures above room temperature to release gases such
as nitrogen, e.g., azo compounds such as azoisobutyric acid
nitrile. Further examples of blowing agents and the use o~
blowing agents are known and have been described, e.g., in
Kunststoff-Handbuch, Volume VII, published by Vieweg and
Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g., on pages 108
and 109, 453 to 455 and 507 to 510.
Catalysts are also ~requently used accordin~ to the
invention. The catalysts added are generally known and
include tertiary amines such as triathylamine, tributylamine,
N-methylmorpholine, N-ethylmorpholine, N-cocomorpholine,
N,N,N',N'-tetramethyl-ethylenediamine, 1,4-diaza-bicyclo-
(2,2,2)-octane, N-methyl-N'-dimethyl-aminoethylpiperazine,
N,N-dimethylbenzylamine, bis-(N,N-diethyl-aminoethyl)-adipate,
N,N diethylbenæylamine, pentamethyldiethylenetriamine, N,N-
dimethylcyclohexylamlne, N,N,N',N'-tetramethyl-1,3 butane-
diamine, N,N-dimethyl-6-phenylethylamine, 1,2-dimethylimi-
dazole and 2-methylimidazole. Mannich bases known per se
obtained from secondary amines such as dimethylamine and
LeA 17,468 -13
, ~ ,
`~ ~
~5~
aldehydes, preferably formaldehyde, or ketones such as acetone,
methyl ethyl ketone or cyclohexanone and phenols such as phenol,
nonylphenol or bis-phenol may also be used as catalysts.
Examples of catalysts which consist of tertiary amines having
hydrogen atoms which are reactive with isocyanate groups
include triethanolamine, triisopropanolamine, N-methyl-
diethanolamine, N-ethyl-diethanolamine, N,N-dimethyl-ethanol-
amine and their reaction products with alkylene oxides such
as propylene oxide and/or ethylene oxide.
Silaamines having carbon-silicon bonds as described,
e.g., in German Patent 1,229,290 and U. S. Patent 3,620,984
may also be used as catalysts. Examples include 2,2,4-
trimethyl-2-silamorpholine and 1,3-diethylaminoethyl-
tetramethyldisiloxane.
Basic nitrogen compounds such as tetraalkylammonium
hydroxides, alkali metal hydroxides such as sodium hydroxide,
alkali metal phenolates such as sodium phenolate and alkali
metal alcoholates such as sodium methylate may also be used as
catalysts. ~exahydrotriazines are al50 suitable catalysts.
Organic metal compounds may also be used as
catalysts according to the invention, in particular organic
tin compounds. The organic tin compounds used are preEexably
tin(II) salts of carboxy~ic acids such as tin(II) acetate,
tin(II) octoake, tin(II) ethyl hexoate and tin(II) laurate
and tin(IV) compounds such as dibutyl tin oxide, dibutyl tin
dichloride, dibutyl tin diacetate, di.butyl tin dilaurate,
dibutyl~ tin maleate or clioctyl tin diacetate~ ~11 the above--
mentioned catalysts may, of course, be used as mixtures.
l~e~ 1~,468 ~14
,
Further examples of catalysts which may be use~
according to the inven-tion and details concerning the activity
of the catalysts are known and are described, e.g., in
Kunststoff-Handbuch, Volume VII, published by Viewe~ and
Hochtlen, Carl-Hanser-Verlag, Munich 1966, pages 96 to 102.
The catalysts, when used, are generally used in a
quantity of between about 0.001 and 10%, by weight, based on
the quantity of primary hydroxyl group containing polyethers.
Surface active additives such as emulsifiers and
foam stabilizers may also be used according to the invenlxion.
Suitable emulsifiers include, e.g., the sodium salts of
ricinoleic sulphonates or salts of fa-tty acids with amines
such as oleic acid diethylamine or stearic acid diethano]-
amine. Alkali metal or ammoni~n salts of sulphonic acids
such as dodecylbenzene sulphonic acid or dinaphthylmethane
disulphonic acid or of fatty acids such as ricinoleic acid
or of polymeric fatty acids may also be used as surface
active additives.
Polyether siloxanes are particularly suitable foam
stabilizers, especially useful are those which are water
soluble. These compounds generally have a polydimethyl
siloxane group attached to a copolymer of ethylene oxide and
pxopylene oxide. Foam stabilizers of this kind are known and
have been described, ~or e~ample, in U. S. Patents 2,834,748;
2,917,480 and 3,629,308. It may, however, be advantageou;, to
carry out the process according to the invention without Eoam
stabilizers.
LeA 17,468 -15-
~5~
Other additives which may also be used according to
the invention include reaction retarders, e.g., substances
which are acid in reaction such as hydrochloric acid or orga:nic
acid halides, cell regulators such as paraffins or fatty
S alcohols or dimethyl polysiloxanes, pigments, dyes, flame
retarding agents such as tris-chloroethyl phosphate, tricresyl
phosphate or ammoni~n phosphate and polyphosphates, stab:ilizers
against ageing and weathering/ plasticizers, fungistatic and
bacteriostatic substances, and fillers such as barium sulphate,
kieselguhr, carbon black or whiting.
Qther examples o:f surface active additives, foam
stabilizers, cell regulators, reaction retarders, sta~
zersj flame retarding substances, plasticizers, dyes, fillers,
and fungistatic and bacteriostatic substances which may be used
according to the invention and details concerning the use and
mode of action of these additives are known and may be found,
e.g., in Kunststoff-Handbuch, Volume VII, published by Vieweg
and Hochtlen, Carl-Hanser-Verlag, Munich 1966, on pages 103
to 113.
According to the invention, the components may be
reacted together by the known one-shot prepolymer or semi-
prepolymer process, often using mechanical devices such as
those described in U. S. Patent 2,764,565. Details concerning
pxocessing apparatus which may be used according to the inven-
tion may be found in Kunststoff-Handbuch, Volume VII, published
by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, pages
121 and 205.
Le~ 17,468 -16-
According to the invention, the foaming reaction i-or
producing foam products is ~ften carried out inside molds. In
this process~ the foamable reaction mixture is introduced into
a mold which rnay be made of a metal such as aluminum or a
plastics material such as an epoxide resin. The reaction
mixture foams up inside the mold to produce the shaped product.
The process of foaming in molds may be carried out to produce
a product having a cellular structure on its surface or it may
be carried out to produce a product having a compact skin and
cellular core. ~ccording to the invention, the desired result
can be obtained by either introducing just sufficient foamable
reaction mixture to fill the mold with foam after the reaCtiQn
is completed or introducing a larger quantity of reaction
mixture than is necessary to fill the mold with foam. The
second method is known as "overpacking", a procedure whi~h is
known and has been disclosed, 2 . g ., in U. S. Patents
3,178,490 and 3~182,1~4.
So-called external mold release agents known in the
art, such as silicone oils, are frequently used when foaming is
carried out inside molds. The process may also be carri~d out
with the aid of so-called internal mold release agents, i~
desired, in combination with external mold release agents,
e.g., as described in German Offenlegungsschriften 2,121,670
and 2,307,589.
Cold setting foams may also be produced, as described~
in British Patent 1,162,517 and German Offenlegungsschrift
2,153,086.
LeA 17,46B -17-
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~XlS9~V~
Foams may, of çourse, also be produced by the
process of block foaming or by the laminator process known
in the art. The products obtainable according to the inven~
tion may be used, for example, as upholstery or paddlng
materials. : :
:
.
,
`:::~: : :: ': :
~ ~ LeA 17,458 ;~ ?
s9~
EXAMP~ES
-
In all examples metal molds were used~ Foaming was c~rried
out at a mold temperature of 50~.
Example 1 (Comparison Example)
A) 100 parts by weight of a polypropylene glycol which
had been started on trimethylolpropane and modified with
ethylene oxide, having a hydroxyl number of 28 with 80% of
primary hydroxyl end groups,
3.2 parts by weight of water,
0~15 parts by weight of diazabicyclo-2,2,2-octane,
0.10 parts by weight of 2,2'-dimethyl-aminodiethylether, and
5 parts by weight of trichlorofluoromethane and
B:) 54.8 parts by weight of a polyisocyanate mixture con-
sisting of 34% by weight of 2,4'-diphenylmethane diisocyanate,
: :l5 51% by weight of 4,4'-diphenylmethane diisocyanate, and
15% ~y welght of oligomeric polyphenylpolymethylene poly-
: isocyanates were reacted together in~a closed mold. Moldrelease time: 8 minutes.
A molded foam product havi~g the following mechanical
properties was obtained:
Gross density DIN 53420 (kg/m3) 44
Tensile strength DIN 53571 (KPa) 130
Elongation at break DIN 53571 (%) 150
Compression strength DIN 53577 (KPa~ s.4
.
~ LeA 17,468 ~ ~19-
~",~
~s~
Example 2
A) 100 parts by weight of a polypropylene glycol which
had been started on trimethylolpropane and modified with
ethylene oxide, having a hydroxyl number o 28 and 85% of
primary hydroxyl end groups,
2.7 parts by weight of water,
0.33 parts by weight of diazabicyclo-2,2,2-octane,
0.1 parts by weight of 2,2' dimethyl-aminodiethylether,
0.5 parts by weight of N methylmorpholine,
0.02 parts by weight of ibutyl tindilaurate,
1.5 parts by weight of gly~erol, and
8 parts by weight of trichlorofluoromethane and
B) 54.0 parts by weight of a polyisocyanate mixture con-
sisting of 5~i by weight of 2,4'-~iphenylmethane diisocyanate,
80~i by weight of 4,4'-diphenylmethane diisocyanate, and
15~i by weight of oligomeric polyphenyl polymethylene poly~
isocyanates were reacted together in a closed mold. Mold
release time: 1 minute.
The molded foam product having the following mechanical
properties was obtained:
Gross density ~l DIN 53420 (kg/m ) 43
Tensile strength ' DIN 53571 (KPa) 105
Elongation at break ~,.DIN 53571 (~i) 130
Compress.i.on strength ~ DIN 53577 (KPa) 5.8
, I ~
LeA 17,463 -20-
:
~5~
Example 3
A) 100 parts by weight of a polypropylene glycol which has
been started on trimethylolpropane and modified with ethylene
oxide, having a primary hydroxyl end group content of 75% and
a hydroxyl number of 35,
2.7 parts by weight of water~
0.33 parts by weight of diazabicyclo-2,2,2-octane,
0.06 parts by weight of 2,2'-dimethyl-aminodiethylether,
0.5 parts by weight of N-methylmorpholine/
: 10 0.2 parts by weight of dibutyl tindilaurate,
1.5 parts by weight of glycerol, and
8 parts by weight of trichlorofluoromethane,
and
B) 50.4 parts by weight of a mixture of 80~ by weight of
polyisocyanate mixture consisting of
~ 10% by weight of 2,4'-diphenylmethane diisocyanate,
: 75~ by weight of 4,4'-diphenylmethane diisocyanate, ancl
15% by weight of oligomeric polyphenyl polymethylene poly-
: isocyanates; 20% by weight of tolylene diisocyanate (2,4- :
2,6-isomer as 80 : 20% by weight) were reacted to~ether in a
closed mold. Mold release time: 1 minute, 30 seconds.
A molded foam product having the following mechanical
properties was obtained:
Gross density DIN 53420 (kg/m3) 42.5
Tensile strength DIM 53571 (KPa) 85
Elongation at break DIN 53571 (~) 145
Compression strength ~ DIN 53577 (KPa) 4.7
LeA 17,468 -21-
Example 4
A) 100 parts by weight of a polypropylene glycol which has
been started on glycerol and modified with ethylene oxide~
having a primary hydroxyl end group content of 80~ and a
hydroxy] number of 28,
3.0 parts by weight of water,
0.55 parts by weight of diazabicyclo-2,2,2-octane,
0.06 parts by weight of 2,2'-dimethyl-aminodiethylether, and
5 parts by weight of trichlorofluoromethane
and
B) 51.75 parts by weight of a polyisocyanate mixture con-
sisting of
26~ by weight of 2,4'-diphenylmethane diisocyanate,
64% by weight of 4/4'-diphçnylmethane diisocyanate, and
10~ by weight of oligomeric polyphenyl polymethylene poly-
isocyanates were reacted together in a closed mold. Mold
release time: 2 minutes, 30 seconds.
A molded foam product having the following mechanical
properties was obtained:
Gross density DIN 53420 (kg/m3)56
Tensile strength DIN 53571 (KPa) 200
Elongation at break DIN 53571 1~) 185
Compression strength ~IN 53577 (KPa) ~j.3
When the same reaction mixture is produced via tle
free use technique, the resulting foam had the following
mechanical properties:
Gross density DIN 53420 (kg/m3)44
Tensile strength DIN 53571 (KPa) 110
Elongation at break DIN 53571 (~) 180
Compression strength DIN 53577 (KPa) 3.2
LeA 17,468 -22-
q
Example 5
A) 100 parts by weight o a polypropylene glycol which has
been started on trime-thylolpropane and moclified with ethylene
oxide, having a primary hydroxyl end group content of 80'~ and
a hydroxyl number of 28,
2.7 parts by weight oE water,
0.20 parts by weight of diazabicyclo-2,2,2-octane,
0.06 parts by weight of 2,2'-dimethyl-aminodiethylether, and
5 parts by weight of trichlorofluoromethane
and
B) 48.8 parts by weight of a polyisocyanate mixture con-
sisting of
10~ by weight of 2,4'-diphenylmethane diisocyanate,
60~ by weight of 4,4'-diphenylmethane diisocyanate, and
30% by weight of oligomeric polyphenyl polymethylene poly-
isocyanates were reacted together in a closed mold. Mold
release time: 2 minutes.
A molded foam product having the following mechanical
properties was obtained:
Gross density DIN 53420 (kg/m3) 43
Tensile strength DIN 53571 (KPa) 80
Elonyation at break DIN 53571 (%) 105
Compression strength DIN 53577 (KPa) 3.8
LeA 17,468 ~ -23~
,: :
~5~
Example 6
A) 100 parts by weight of a polypropylene glycol which had
been started on trimethylolpropane and modified with ethylene
oxide, having a hydroxyl number oE 28 with 60~ of primary
hydroxyl end groups,
3.0 parts by weight of water,
0.5 parts by weight of diazabicyclo-2,2,2-octane~
0.06 parts by weight of 2,2'-dimethyl-aminodiethylether, and
S parts by weight o~ trichlorofluoromethan~ and
B) 51.7S parts by weight of a polyisocyanate mixture con-
sisting of 26% by weight of 2,4'-diphenylmethane diisocyanate,
69~ by weight of 4,4' diphenylmethane diisocyanate, and
5~ by weight of oligomeric polyphenylpolymethylene poly-
isocyanates were reacted together in a closed mold. Mold
release time: 2 minutes, 30 seconds.
A molded foam product having the following mechanical
properties was obtained:
Gross density DIN 53420 (kg/m3)51
Tensile strength D~N 53571 (KPa)205
Elongation at break DIN 53571 (%) 215
Compression strength DIN 53577 (KPa) 5
LeA 17,468 1~ -24-
Example 7
Preparation of a flexible integral skin foam.
95 parts by weight of a polypropylene glycol which has been
started on trimethylolpropane and modified with ethylene
oxide, having a primary hydroxyl end group content of 80~ and
a hydroxyl number of 28,
ethylene ~lycol 5 parts by weight,
water 0.4 parts by weight,
diazabicyclo-2,2,2-octane 0.35 parts by weight,
tetramethyl ethylenediamine 0.5 parts by weight, and
trlchlorofluoromethane 8 parts by weight
were stirred toyether. They were then mixed with 28.0 parts
by weight of a polyisocyanate mixture consisting of
2,4'-diphenylmethane diisocyanate 10~ by weight
I5 4,4'-diphenylmethane diisocyanate 75% by weight
oligomeric polyphenyl polymethylene
polyisocyanates 15% by weight
The reaction mixture was poured into a closed mold.
A molded foam product having an integral skin (soft integral
foam) was obtained. It had the following properties:
Gross density DIN 53420 Ikg/m ) 105
Tensile strength DIN 53571 (KPa) 135
Elongation at break DIN 53571 (%~ 115
Compression resistance DIN 53577 (KPa) 13.5
The mold release time was 2 minutes.
LeA 17,468 -25~
