 |
Description  |
|
|
BACKGROUND OF THE INVENTION
It is known that the flame resistance of synthetic resins, in particular
polyurethanes resins, can be increased by the addition of unreactive low
molecular weight phosphoric or phosphonic acid esters during the
manufacturing process. This procedure is, however, limited by the fact
that if the desired mechanical properties are to be obtained, these low
molecular weight compounds may only be used in such limited quantities
that they are insufficient to ensure complete flame resistance. The
procedure is also limited by the fact that these additives tend to migrate
from the resin, because of their low molecular weight.
Attempts have been made to overcome this difficulty by incorporating
halogen containing polycarboxylic acids or polyhydroxyl compounds into the
molecular structure. Such halogenated components include
tetrachlorophthalic acid, dibromophthalic acid or hexachloroendomethylene
tetrahydrophthalic acid. Polyesters produced from such components have a
much improved flame resistance (e.g. after they have been foamed with
polyisocyanates), but such resistance is still insufficient in many cases.
Other disadvantages lie in the fact that these polyesters are difficult to
mix with polyisocyanates at room temperature because of their high
viscosity, so that processing difficulties arise during the production of
foams. Moreover, these polyesters tend to give rise to brittle foams when
reacted with polyisocyanates so that they can only be converted into foams
of satisfactory mechanical quality if they are mixed with the usual
polyesters. In that case, however, the flame resistance achieved is partly
lost. Furthermore, many of the conventional halogen containing flame
retarding agents liberate corrosive gases such as hydrogen chloride or
hydrogen bromide on combustion.
Flame resistant polyurethane resins which have good mechanical properties
are obtained when using polyisocyanates which contain phosphoric acid or
thiophosphoric acid groups (for example, the p-isocyanatophenyltriester of
phosphoric acid). Phosphoric ester triisocyanates, however, can only be
obtained by multistage processes and their use is therefore often
uneconomical.
Hydrocarbon phosphonyl diisocyanates have also been used for the production
of flame resistant foams. These diisocyanates, however, are acyl
isocyanates, which are not only physiologically unpleasant because of
their odor and vapor pressure but also because they are excessively
reactive and readily saponified. Satisfactory foams, then, can only be
obtained using usch isocyanates if the isocyanates are mixed with
considerable quantities of the usual polyisocyanates such as tolylene
diisocyanate. It is obvious, however, that the flame retarding properties
are then lost.
The use of phosphorus containing polyether and polyester polyols for the
production of polyurethane foams is also known in the art. These products,
however, give rise to copious production of fumes when subjected to heat.
Moreover, they are in many cases difficult to handle because of their
viscosity which may interfere with the foaming process.
DESCRIPTION OF THE INVENTION
It has now been found that non-flammable or substantially non-flammable
polyurethane resins can be obtained without the disadvantages of the known
flame retarding agents described above if novel polyols which contain a
phosphorus substituted s-triazine ring are used as reactants in the
preparation of the polyurethane.
This invention relates to flame retarding agents of the following general
formula which are free from halogen groups and which are reactive with
isocyanates:
##STR3##
in which: R.sub.1 represents optionally branched C.sub.1 -C.sub.5 alkyl
groups,
R.sub.2 represents optionally branched C.sub.1 -C.sub.5 alkyl groups or
R.sub.1 OH and
R.sub.3 represents C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.8 -dialkylamino,
C.sub.1 -C.sub.4 -oxyalkyl, C.sub.1 -C.sub.4 -thioalkyl, C.sub.6 -C.sub.14
-aryl, C.sub.7 -C.sub.15 -aralkyl groups, or, preferably
##STR4##
wherein A and L which may be identical or different, represent optionally
branched C.sub.1 -C.sub.10 -alkyl groups, benzyl or, preferably, the group
OR wherein R denotes an optionally branched alkyl group containing 1 - 8,
and preferably 1 - 4 C atoms, or a benzyl group.
The compounds according to the invention are prepared by a two-stage or
three-stage substitution of the halogen atoms of cyanuric chloride or
cyanuric fluoride in any sequence.
Either the groups
##STR5##
and optionally R.sub.3 are successively introduced into the compounds
##STR6##
which are suspended in inert organic solvents such as acetylene
tetrachloride, methyl chloroform, pentachloroethane or liquid
hydrocarbons, such as toluene or dichloroethane, or the following
compounds are first synthesized:
##STR7##
and then reacted with alkanolamines of the general formula
##STR8##
A, L, R.sub.1, R.sub.2 and R.sub.3 having the same meaning as above.
The reaction between the halogen attached to the triazine ring and
compounds of the general formula:
##STR9##
in which A, L and R have the meaning defined above (phosphorus,
phosphonous or phosphinous acid ester) proceeds in a manner analogous to
the known Michaelis-Arbusov reaction, preferably in the one of the inert
solvents mentioned above, and results in almost quantitative yields at
temperatures of 50.degree. to 150.degree. C, preferably 70.degree. to
130.degree. C. The reaction can be controlled by suitable choice of the
molar quantities of starting components so that either one or two of the
halogen atoms attached to the s-triazine ring can be substituted by
##STR10##
The process of the reaction can easily be followed by collecting the RX
formed during the Michaelis-Arbusov reaction and measuring it
volumetrically, e.g. by means of a gas meter.
Introduction of the substituents R.sub.3 and
##STR11##
into the s-triazine ring is carried out by methods known per se. Reference
is made to J. T. Thurston et al. in J. Amer. Chem. Soc. 73, 2983(1951).
The following are typical examples of compounds according to the invention:
##STR12##
The phosphorus containing polyols according to the invention are used as
reactants together with polyisocyanates, other high molecular weight
and/or lower molecular weight polyols and optionally other compounds
containing groups which are reactive with isocyanates, for the production
of polyurethanes, such as, lacquers, foils, coatings, elastomers and
fillers, but preferably polyurethane foams. In order to ensure sufficient
flame resistance, the polyols according to the invention are used in a
quantity such that the finished polyurethane resin contains at least 0.5%
by weight phosphorus.
This invention therefore also relates to a process for the preparation of
polyurethanes from polyisocyanates, high molecular weight and/or low
molecular weight polyols and optionally other compounds containing groups
which are reactive with isocyanates, characterized in that compounds of
the following general formula which are reactive with isocyanates:
##STR13##
wherein: A, L, R.sub.1, R.sub.2 and R.sub.3 have the meanings defined
above, are used in such a quantity that the polyurethane contains at least
0.5% by weight of phosphorus.
The simplest technical method of producing polyurethane foams consists of
mixing the compounds of the invention, either alone or together, with
other polyol components (polyethers or polyesters). These polyol mixtures,
together with the foam activators, catalysts, blowing agents, mold release
agents, pore regulators, emulsifiers and other auxiliary agents, are mixed
with the isocyanate component. This reaction mixture is then foamed either
freely or in a closed mold to form an integral foam having a non-cellular
skin and cellular core. The formulations of the reaction mixtures are
adjusted so that the effective phosphorus content is 0.5 to 10% by weight,
preferably 1 to 4% by weight, based on the total mixture.
The isocyanates used as starting components according to the invention may
be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic
polyisocyanates such as those described e.g. by W. Siefken in Justus
Liebigs Annalen der Chemie, 562, pages 75 to 136. Examples include
ethylene diisocyanate; tetramethylene-1,4-diisocyanate;
hexamethylene-1,6-diisocyanate; dodecane-1,12-diisocyanate;
cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and 1,4-diisocyanate and
mixtures of these isomers;
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane as described in
U.S. Pat. No. 3,401,190; hexahydrotolylene-2,4- and -2,6-diisocyanate and
mixtures of these isomers; hexahydrophenylene-1,3- and/or
1,4-diisocyanate; perhydrodiphenylmethane-2,4'- and/or 4,4'-diisocyanate;
phenylene-1,3- and -1,4-diisocyanate; tolylene-2,4- and -2,6-diisocyanate
and mixtures of these isomers; diphenylmethane-2,4'- and/or
4,4'-diisocyanate; naphthylene-1,5-diisocyanate;
triphenylmethane-4,4',4"-triisocyanate; polyphenyl-polymethylene
polyisocyanates which can be obtained by aniline formaldehyde condensation
followed by phosgenation as described in British Pat. Nos. 874,430 and
848,671; m- and p- isocyanatophenyl-sulphonylisocyanates as described in
U.S. Pat. No. 3,454,606; perchlorinated aryl polyisocyanates as described
in U.S. Pat. No. 3,277,138; polyisocyanates which contain carbodiimide
groups as described in U.S. Pat. No. 3,152,162; diisocyanates as described
in U.S. Pat. No. 3,492,330; polyisocyanates which contain allophanate
groups as described in British Pat. No. 994,890, Belgian Pat. No. 761,626
and published Dutch Patent Application No. 7,102,524; polyisocyanates
which contain isocyanurate groups as described in U.S. Pat. No. 3,001,973,
German Pat. Nos. 1,022,789; 1,222,067 and 1,027,394 and German
Offenlegungsschriften Nos. 1,929,034 and 2,004,048; polyisocyanates which
contain urethane groups as described in Belgian Pat. No. 752,261 or U.S.
Pat. No. 3,394,164; polyisocyanates which contain acylated urea groups as
described in German Pat. No. 1,230,778; polyisocyanates which contain
biuret groups as described in U.S. Pat. Nos. 3,124,605 and 3,201,372, and
British Pat. No. 889,050; polyisocyanates prepared by telomerization
reactions as described in U.S. Pat. No. 3,654,106; polyisocyanates which
contain ester groups as described in British Pat. Nos. 965,474 and
1,072,956, U.S. Pat. No. 3,567,763 and German Pat. No. 1,231,688; and
reaction products of the above mentioned isocyanates with acetals as
described in German Pat. No. 1,072,385, as well as polyisocyanates which
contain polymeric fatty acid groups as described in U.S. Pat. No.
3,455,883.
The distillation residues obtained from the commercial production of
isocyanates which still contain isocyanate groups may also be used, if
desired, as solutions in one or more of the above mentioned
polyisocyanates. Any mixtures of the above mentioned polyisocyanates may
also be used.
It is generally particularly preferred to use readily available
polyisocyanates such as tolylene-2,4- and -2,6-diisocyanate and mixtures
of these isomers ("TDI"), polyphenylpolymethylene-polyisocyanates which
can be obtained by aniline formaldehyde condensation followed by
phosgenation ("crude MDI"); and polyisocyanates which contain carbodiimide
groups, urethane groups, allophanate groups, isocyanurate groups, urea
groups or biuret groups ("modified polyisocyanates").
The starting components to be used according to the invention also include
compounds which contain at least two hydrogen atoms capable of reacting
with isocyanates, and which generally have a molecular weight of 400 to
10,000. Suitable compounds of this kind include not only compounds
containing amino groups, thiol groups or carboxyl groups but also in
particular polyhydroxyl compounds, and especially those containing two to
eight hydroxyl groups and having a molecular weight of 600 to 8000,
preferably 800 to 6000, such as polyesters, polyethers, polythioethers,
polyacetals, polycarbonates or polyester amides containing at least 2,
generally 2 to 8 but preferably 2 to 4 hydroxyl groups. These materials
are of the kind which are known per se for the production both of
homogeneous and of cellular polyurethanes.
The polyesters having hydroxyl groups which may be used as starting
components include reaction products of polyhydric alcohols, preferably
dihydric alcohols with the optional addition of trihydric alcohols, and
polybasic, preferably dibasic carboxylic acids. Instead of free
polycarboxylic acids, the corresponding polycarboxylic anhydrides or
corresponding polycarboxylic acid esters of lower alcohols or their
mixtures 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. with halogen atoms, and/or unsaturated. The
following are examples: succinic acid, adipic acid, suberic acid, azelaic
acid, sebasic acid, phthalic acid, isophthalic acid, trimetallic acid,
phthalic acid anhydride, tetrahydrophthalic acid anhydride,
hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride,
endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride,
maleic acid, maleic acid anhydride, fumaric acid, dimeric and trimeric
fatty acids such as oleic acid, if desired mixed with monomeric fatty
acids, dimethyl terephthalate or bis-glycol terephthalate. Suitable
polyhydric alcohols include e.g. ethylene glycol, propylene-1,2- and
-1,3-glycol , butylene-1,4- and -2,3-glycol, hexane-1,6-diol,
octane-1,8-diol, neopentyl glycol, cyclohexane dimethanol
(1,4-bis-hydroxy-methylcyclohexane), 2-methyl-propane-1,3-diol, glycerol,
trimethylolpropane, hexane-1,2,6-triol, butane-1,2,4-triol,
trimethylolethane, pentaerythritol, quinitol, mannitol and sorbitol,
methyl glycoside, diethylene glycol, triethylene glycol, tetraethylene
glycol, polyethylene glycols, dipropylene glycol, polypropylene glycols,
dibutylene glycol and polybutylene glycols. The polyesters may also
contain a proportion of carboxyl groups in end positions. Polyesters of
lactones such as .epsilon.-caprolactone or hydroxy-carboxylic acids such
as .omega.-hydroxycaproic acid may also be used.
The hydroxyl polyethers which may be used according to the invention and
which contain at least two, generally two to eight, preferably two or
three hydroxyl groups are also known per se, and are obtained, for
example, by the polymerization of epoxides such as ethylene oxide,
propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or
epichlorohydrin, either alone, for example in the presence of BF.sub.3, or
by addition of these opoxides, optionally as mixtures or or successively,
to starting components which contain reactive hydrogen atoms, such as
water alcohols or amines, e.g. ethylene glycol, propylene-1,3- or
-1,2-glycol, trimethylolpropane, 4,4'-dihydroxy-diphenylpropane, aniline,
ammonia, ethanolamine and ethylene diamine. Sucrose polyethers as
described in German Auslegeschriften Nos. 1,176,358 and 1,064,398 may also
be used according to the invention. In many cases it is preferred to use
polyethers of the kind which contain predominant amounts of primary OH
groups (up to 90% by weight, based on all the OH groups present in the
polyether). Polyethers which are modified with vinyl polymers, e.g. the
compounds obtained by the polymerization of styrene and acrylonitrile in
the presence of polyethers (U.S. Pat. Nos. 3,383,351; 3,304,273; 3,523,093
and 3,110,695, and German Pat. No. 1,152,536) are also suitable, as are
polybutadienes which contain OH groups.
Suitable polythioethers include in particular the condensation products
obtained from the condensation of thiodiglycol either on its own or with
other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or
amino alcohols. The products obtained are polythio mixed ethers,
polythioether esters or polythioether ester amides, depending on the
components.
Suitable polyacetals include e.g. the compounds which can be prepared from
glycols such as diethylene glycol, triethylene glycol,
4,4'-dioxethoxy-diphenyldimethylmethane, hexanediol and formaldehyde.
Polyacetals suitable for the purpose of the invention may also be prepared
by the polymerization of cyclic acetals.
The polycarbonates having hydroxyl groups include those which can be
prepared by the reaction of diols such as propane-1,3-diol,
butane-1,4-diol and/or hexane-1,6-diol, diethylene glycol, triethylene
glycol, or tetraethylene glycol, with diaryl carbonates, such as
diphenylcarbonate, or phosgene.
Suitable polyester amides and polyamides include the predominantly linear
condensates obtained from polybasic saturated and unsaturated carboxylic
acids or their anhydrides and polybasic saturated and unsaturated amino
alcohols, diamines, polyamines and mixtures thereof.
Polyhydroxyl compounds which already contain urethane or urea groups and
modified or unmodified natural polyols such as castor oil, carbohydrates
or starch may also be used. Addition products of alkylene oxides and
phenol formaldehyde resins or urea formaldehyde resins may also be used
according to the invention.
These types of compounds which can be used in the invention have been
described in e.g. High Polymers Vol. XVI, "Polyurethanes, Chemistry and
Technology" by Saunders-Frisch, Interscience Publishers, New York, London,
Volume I, 1962, pages 32-42 and pages 44-54 and Volume II, 1964, pages 5-6
and 198-199, and Kunststoff-Handbuch, Volume VII, Vieweg-Hochtlen,
Carl-Hanser-Verlag, Munich 1966, e.g. on pages 45 to 71.
The starting components used according to the invention may also include
compounds having a molecular weight of 32 to 400 which contain at least
two hydrogen atoms capable of reacting with isocyanates. These also are
compounds containing 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 crosslinking agents.
These compounds generally contain 2 to 8 hydrogen atoms capable of
reacting with isocyanates, preferably two or three such hydrogen atoms.
The following are examples of such compounds: Ethylene glycol,
propylene-1,2- and -1,3-glycol, butylene-1,4- and -2,3-glycol,
pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, neopentyl glycol,
1,4-bis-hydroxymethylcyclohexane, 2-methyl-propane-1,3-diol, glycerol,
trimethylol-propane, hexane-1,2,6-triol, trimethylolethane,
pentaerythritol, quinitol, mannitol, sorbitol, diethylene glycol,
triethylene glycol, tetraethylene glycol, polyethylene glycols having a
molecular weight of up to 400, dipropylene glycol, polypropylene glycols
having a molecular weight of up to 400, dibutylene glycol polybutylene
glycols having a molecular weight of up to 400,
4,4'-dihydroxydiphenylpropane, dihydroxymethylhydroquinone, ethanolamine,
diethanolamine, triethanolamine, 3-aminopropanol, ethylene diamine,
1,3-diaminopropane, 1-mercapto-3-aminopropane, 4-hydroxy- or
-aminophthalic acid, succinic acid, adipic acid, hydrazine,
N,N'-dimethylhydrazine and 4,4'-diaminodiphenylmethane.
Water and/or readily volatile organic substances may also be included as
blowing agents according to the invention. Suitable organic blowing agents
include acetone, ethyl acetate, halogenated alkanes such as methylene
chloride, chloroform, ethylidene chloride, vinylidene chloride,
monofluorotrichloromethane, chlorodifluoromethane or
dichlorodifluoromethane, or butane, hexane, heptane or diethylether. The
effect of a blowing agent may also be obtained by the addition of
compounds which decompose at temperatures above room temperature to
liberate gases. Such compounds include nitrogen, for example azo compounds
such as azo isobutyric acid nitrile. Other examples of blowing agents and
details concerning the use of blowing agents may be found in
Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen,
Carl-Hanser-Verlag, Munich 1966, e.g. on pages 108 to 109, 453 to 455 and
507 to 510.
Catalysts are also often used according to the invention. The catalysts may
be of the kind already known per se, for example tertiary amines such as
triethylene, tributyl-amine, N-methylmorpholine, N-ethylmorpholine,
N-cocomorpholine, N,N,N',N'-tetramethyl-ethylenediamine,
1,4-diaza-bicyclo-(2,2,2)-octane,
N-methyl-N'-dimethylaminoethylpiperazine, N,N-dimethylbenzylamine,
bis-(N,N-diethylaminoethyl)-adipate, N,N-diethylbenzylamine, pentamethyl
diethylene-triamine N,N-dimethylcyclohexylamine,
N,N,N',N'-tetramethyl-1,3-butanediamine,
N,N-dimethyl-.beta.-phenylethylamine, 1,2-dimethylimidazole and
2-methylimidazole. Known Mannich bases of secondary amines such as
dimethylamine and aldehydes, preferably formaldehyde; or ketones such as
acetone, methyl ethyl ketone or cycohexanone and phenols such as phenol,
nonylphenol or bis-phenol may also be used as catalysts.
Suitable catalysts in the form of tertiary amines which contain hydrogen
atoms capable of reacting with isocyanate groups include e.g.
triethanolamine, triisopropanolamine, N-methyl-diethanolamine,
N-ethyl-diethanolamine and N,N-dimethyl-ethanolamine as well as their
reaction products with ethylene oxides such as propylene oxide and/or
ethylene oxide.
Silaamines containing carbon-silicon bonds as described in U.S. Pat. No.
3,620,984 may also be used as catalysts including
2,2,4-trimethyl-2-silamorpholine or
1,3-diethylaminomethyl-tetramethyl-disiloxane.
Bases which contain nitrogen, such as tetraalkylammonium hydroxides, or
alkali metal hydroxides such as sodium hydroxide, alkali metal phenolates
such as sodium phenolate or alkali metal alcoholates such as sodium
methylate may also be used as catalysts. Hexahydrotriazines are also
suitable catalysts.
Organic metal compounds may be used as catalysts according to the
invention, in particular organic tin compounds.
The organic tin compounds used are preferably tin(II) salts of carboxylic
acids, such as tin(II) acetate, tin(II) octoate, tin(II) ethyl hexoate and
tin(II) laurate and the tin(IV) compounds such as dibutyl tin oxide,
dibutyl tin dichloride, dibutyl tin diacetate, dibutyl tin dilaurate,
dibutyl tin maleate or dioctyl tin diacetate. Any of the above mentioned
catalysts may, of course, also be used as mixtures.
Other examples of catalysts which may be used according to the invention
and details concerning their activity may be found in Kunststoff-Handbuch,
Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich
1966, e.g. on pages 96 to 102.
The catalysts are generally used in a quantity of between about 0.001 and
10% by weight, based on the quantity of compounds having a molecular
weight of 400 to 10,000 which contain at least two hydrogen atoms capable
of reacting with isocyanates.
Surface active additives such as emulsifiers and foam stabilizers may also
be used according to the invention. Suitable emulsifiers include the
sodium salts of ricinoleic sulphonates or salts of fatty acids with
amines, such as oleic acid diethylamine or stearic acid diethanolamine.
Alkali metal or ammonium salts of sulphonic acids such as dodecylbenzene
sulphonic acid or dinaphthylmethane disulphonic acid or salts of fatty
acids such as ricinoleic acid or of polymeric fatty acids may also be used
as surface active additives.
The foam stabilizers used are mainly polyether siloxanes, especially those
which are water-soluble. These compounds generally have a
polydimethylsiloxane group attached to a copolymer of ethylene oxide and
propylene oxide. Foam stabilizers of this kind have been described in U.S.
Pat. Nos. 2,834,748; 2,917,480 and 3,629,308.
Reaction retarders, e.g. substances which are acidic in reaction such as
hydrochloric acid or organic acid halides; and cell regulators known per
se such as paraffins or fatty alcohols or dimethylpolysiloxanes, pigments
or dyes; stabilizers against ageing and weathering; plasticizers,
fungistatic and bacteriostatic substances and fillers such as barium
sulphate, kieselguhr, carbon black or whiting may also be used according
to the invention.
Other examples of surface active additives, foam stabilizers, cell
regulators, reaction retarders, stabilizers, plasticizers, dyes, fillers
and fungistatic and bacteriostatic substances which may be used according
to the invention and details concerning methods of using these additives
and their mode of action are described in Kunststoff-Handbuch, Volume VII,
published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on
pages 103 to 113.
According to the invention, the components are reacted together by the
known one-step process, prepolymer process or semiprepolymer process, in
many cases using mechanical devices such as those described in U.S. Pat.
No. 2,764,565. Details concerning processing apparatus which may also be
used in the invention may be found in Kunststoff-Handbuch, Volume VII,
published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, e.g. on
pages 121 to 205.
According to the invention, production of the foam is in many cases carried
out by foaming inside molds. In this method, the reaction mixture is
introduced into a mold which may be made of a metal such as aluminium, or
a synthetic resin such as an epoxide resin. The reaction mixture foams up
inside the mold to form the molded product. Foaming in the mold may either
be carried out in such a way that the molded product obtained has a
cellular structure on its surface or it may be carried out to produce a
molded product with a compact skin and cellular core. In other words, the
reaction mixture may either be introduced into the mold in a quantity just
sufficient to enable the resulting foam to fill the mold or it may be
introduced in a larger quantity, in which case foaming is said to be
carried out under conditions of overcharging, a procedure which has
already been disclosed, in e.g. U.S. Pat. Nos. 1,178,490 and 3,182,104.
So-called external mold release agents, such as silicone oils, are
frequently used for foaming in the mold, but if desired, so-called
internal mold release agents of this kind disclosed in German
Offenlegungsschriften Nos. 2,121,670 and 2,307,589 may be used, if desired
together with external mold release agents.
Cold setting foams may also be produced according to the invention (see,
e.g., British Pat. No. 1,162,517 and German Offenlegungsschriften No.
2,153,086).
Foams may, of course, also be produced by the process of block foaming or
by the double conveyor belt process which is known per se.
The following Examples serve to explain the present invention. The parts
and percentages given represent parts by weight or percentages by weight
unless otherwise indicated.
EXAMPLE 1
2-Diethanolamino-4,6-bis-(diethoxyphosphono)-s-triazine
184.4 g (1 mol) of cyanuric chloride are suspended in 300 ml of partly
distilled toluene and heated to 90.degree. C. 332 g (2 mol) of
triethylphosphite are added dropwise during 31/2 hours with stirring. A
slight temperature rise is observed during this time. The reaction mixture
is then heated under reflux for 11/2 hours. A gas meter attached to the
apparatus indicated an ethyl chloride volume of 42.2 l at 20.degree. C.
When the reaction mixture has cooled to room temperature, 210 g (2 mol) of
diethanolamine are added dropwise after it has been mixed with 20 ml of
methylene chloride to prevent any recrystallization in the dropping
funnel. The reaction temperature is kept within the range of 25.degree. to
40.degree. C by cooling with water. The mixture is then stirred for 11/2
hours at room temperature and the toluene is drawn off in a water jet
vacuum at 60.degree. C. The residue is taken up with 11/2 liters of
methylene chloride, and the hydrochloride of diethanolamine is extracted
with a small quantity of water. The aqueous phase is reextracted with
methylene chloride and finally the total quantity of methylene chloride is
evaporated off in a high vacuum. An orange colored oil remains behind.
Yield: 402 g = 87.8% of the theory (based on cyanuric chloride). The
structure of this substance is confirmed by the following spectroscopic
data:
Identified bands in the IR spectrum: OH (3375 cm.sup.-1), P.dbd.O (1240
cm.sup.-1), PO-alkyl (1010 cm.sup.-1), .sup.1 H--NMR (in CDCl.sub.3):
.delta. = 1.4 ppm: Triplet corresponding to the CH.sub.3 of the
diethoxyphosphono group
.delta. = 3.85 ppm: Pseudosinglet (multiplet which is not broken up) of the
N--CH.sub.2 --CH.sub.2 --O group
.delta. = 4.45 ppm: Multiplet (5 lines) belonging to the CH.sub.2 of the
diethoxyphosphono groups (split up by the P-atom)
.delta. = 4.6 ppm: singlet of the OH group (exchangeable by addition of
D.sub.2 O).
EXAMPLE 2
2-[Di-(2'-hydroxypropyl)-amino]-4,6-bis-(diethoxyphosphono)-s-triazine
(a) 184.4 g (1 mol) of cyanuric chloride in 300 ml of toluene (partly
distilled) are reacted with 332 g (2 mol) of triethylphosphite and 226 g
(2 mol) of di-(2-hydroxypropyl) amine as described in Example 1.
Yield: 442 g of an orange colored oil.
A sample of this oil dissolved in toluene and precipitated with petroleum
ether gives the following results on analysis:
Calculated: C 42.4% H 7.1% N 11.5% P 12.8% Found: C 42.5% H 7.3% N 11.5% P
12.8%
(b) 184.4 g (1 mol) of cyanuric chloride in 300 ml of partly distilled
1,2-dichloroethane are reacted with 332 g (2 mol) of triethylphosphite and
226 g (2 mol) of di-(2-hydroxypropyl)-amine as described in Example 1.
After extraction of the hydrochloride and evaporation of dichloroethane,
an orange colored oil remains behind, the IR data of which agree with
those of the oil described under 2(a).
EXAMPLE 3
2-(2'-Methoxy-ethoxy)-4-[di-(2'-hydroxypropyl)-amino]-6-diethoxyphosphono-s
-triazine
224 g (1 mol) of 2-(2'-methoxy-ethoxy)-4,6-dichloro-s-triazine are heated
under reflux in 300 ml of partly distilled 1,2-dichloroethane, and 166 g
(1 mol) of triethylphosphite are added dropwise during 21/2 hours. The
reaction ceases after the evolution of 18.2 1 of gaseous ethyl chloride.
226 g (2 mol) of di-(2-hydroxypropyl)-amine are added to the clear solution
during 21/2 hours under conditions of cooling with water so that the
reaction temperature does not exceed 45.degree. C. Stirring in continued
for a further 2 hours at room temperature and the hydrochloride is then
extracted with water and dichloroethane is evaporated off under vacuum.
The product, a yellowish oil, weighs 290 g.
The .sup.1 H-NMR spectrum shows the following data (taken in CDCl.sub.3):
.delta. = 1.35 ppm: Multiplet (8 lines), belonging to the CH.sub.3 of the
hydroxypropyl- and ethoxy- groups.
.delta. = 3.4 ppm: Singlet of the methoxy group
.delta. = 4.7 ppm: Singlet of the OH groups
The signals of the remaining H atoms are found in the region of .delta. =
3.1-4.65; they consist of two multiplet groups.
EXAMPLE 4
2,4-Bis-(N-Methyl-ethanolamino)-6-diethoxyphosphono-s-triazine
184.4 g (1 mol) of cyanuric chloride are suspended in 300 ml of partly
distilled 1,2-dichloroethane and heated to reflux. 166 g (1 mol) of
triethylamine are added dropwise during 21/2 hours. When 21.11 1 of
gaseous ethyl chloride have evolved, the reaction mixture is cooled to
room temperature and 300.5 g (4 mol) of N-methyl-ethanolamine are added
dropwise under conditions of cooling with water so that the reaction
temperature does not rise above 45.degree. C. Stirring is then continued
for 3 hours at 45.degree. C. The amine hydrochloride is removed from the
organic phase by extraction with water while the dichloroethane phase is
concentrated by evaporation. A viscous, yellowish oil remains behind.
Yield: 236 g (65% of the theory, based on cyanuric chloride) .sup.1 H-NMR
data (CDCl.sub.3):
.delta. = 1.35 ppm: Triplet, corresponding to the CH.sub.3 of the
diethoxyphosphono group
.delta. = 3.15 ppm: Singlet of the N--CH.sub.3 groups
.delta. = 3.7 ppm: Pseudosinglet from N--CH.sub.2 --CH.sub.2 --O
.delta. = 4.3 ppm: Multiplet (5 lines) of the methylene groups
(diethoxyphosphono group)
The singlet signal of the OH groups is superimposed on this multiplet:
.delta. = 4.15 ppm.
EXAMPLE 5
2-[Di-(2'-Hydroxypropyl)-amino]-4-diethylamino-6-diethoxyphosphono-s-triazi
ne
184.4 g (1 mol) of cyanuric chloride are heated to reflux in 300 ml of
partly distilled 1,2-dichloroethane. 166 g (1 mol) of triethylphosphite
are added dropwise during 2 hours. The reaction mixture is then stirred
until a gas meter attached to the apparatus indicates that 20.2 1 of
gaseous ethyl chloride have been evolved. 266.4 g (2 mol) of
di-(2-hydroxypropyl)-amine are added dropwise at room temperature during 2
hours, the temperature being controlled so that it does not rise above
45.degree. C, and the mixture is then stirred for a further 31/2 hours at
40.degree. C. The amine hydrochloride is then removed from the organic
phase by extraction with water at room temperature. The dichloroethane
phase is evaporated under vacuum and the oil which remains behind,
amounting to 324 g (0.884 mol of intermediate product) is dissolved in 300
ml of dichloroethane.
122.6 g (1.76 mol) of diethylamine are then added to this solution during
one hour. The solution is then stirred for 21/2 hours at 45.degree. C.
Yield: 240 g of yellow oil (57.3% based on cyanuric chloride) .sup.1 H-NMR
data (CDCl.sub.3):
.delta. = 1.3 ppm: Multiplet (7 lines) due to the CH.sub.3 of the
diethylamino, diethoxyphosphono and hydroxypropyl group. The signals of
the other hydrogen atoms (two multiplets with 5 lines each) are found in
the region of .delta. = 3.3-4.3 ppm;
.delta. = 5.1 ppm singlet of the OH group.
EXAMPLE 6
2-[Di-(2'-hydroxypropyl)-amino]-4-methyl-6-diethoxyphosphono-s-triazine
164 g (1 mol) of 2-methyl-4,6-dichloro-s-triazine are suspended in 280 ml
of partly distilled 1,2-dichloroethane and heated to reflux. 166 g (1 mol)
of triethylphosphite are then added dropwise during 21/2 hours. When 21.2
1 of gaseous ethyl chloride have been evolved, the reaction mixture is
left to cool to room temperature and 266 g (2 mol) of
di-(2-hydroxypropyl)amine are then added at such a rate that the reaction
temperature does not rise above 45.degree. C. (Time taken for additional
21/4 hours). After the reaction mixture has been stirred for a further 2
hours, the amine hydrochloride is extracted with water and the
dichloroethane phase is evaporated under vacuum. Yield: 195 g (53.9%,
based on methyl-dichloro-s-triazine); yellow oil. A sample of this oil
dissolved in toluene and precipitated with petroleum ether is found to
have the following structural data in the .sup.1 H-NMR spectrum
(CDCl.sub.3):
.delta. = 1.15 ppm: Multiplet (5 lines) belonging to the CH.sub.3 of the
hydroxypropyl and ethoxy groups
.delta. = 2.4 ppm: Singlet of the 4-methyl group
.delta. = 5.0 ppm: Singlet of the OH groups
The signals of the remaining H atoms (two multiplets) are situated in the
range of .delta. = 3.5-4.6 ppm.
EXAMPLE 7
Compound A
22 g of a polyether polyol prepared by the addition of propylene oxide to
trimethylolpropane (OH number 850),
15 g of a polyether polyol prepared by successive addition of propylene
oxide and ethylene oxide to trimethylol propane (OH number 42),
10 g of monofluorotrichloromethane,
0.5 g of a commercial polyether polysiloxane foam stabilizer (OS 50 of
Bayer AG)
2.5 g of dimethylbenzylamine,
0.3 g of tetramethylguanidine,
50 g of the compound according to Example 1.
Compound B
83 g of a commercial crude 4,4'-diisocyanatodiphenylmethane (NCO content
31.3%).
The constituents of Component A are weighed in together and vigorously
mixed. Component B is then stirred in and the finished reaction mixture is
introduced into a temperature controlled aluminum mold which is at
60.degree. C. The reaction mixture begins to foam after 40 seconds
(measured from the moment when Components A and B have been stirred
together). It fills the mold under a foaming pressure and then hardens.
After 15 minutes, a hardened integral foam plate 10 mm in thickness can be
removed from the mold. It has a gross density of 0.54 g/cm.sup.3 and
contains 4% of bound phosphorus, based on the cross-linked resin mass.
Test for fire resistance:
(1) According to UL-Subj. 94 (V text).
Total after-burning time in 5 .times. 2 flame tests: 24 seconds
Classification: UL-VO
(2) according to CSA C 22.2/No. 1-64 Section 6, 13
Classification: passed
After-burning time: 1, 7, 12, 9, 23 seconds.
EXAMPLE 8
Component A
45 g of a polyether polyol (trimethylolpropane, chain lengthened with
propylene oxide, OH number 850),
30 g of a polyether polyol (trimethylolpropane, chain lengthened with
propylene oxide and ethylene oxide, OH number 42),
10 g of monofluorotrichloromethane,
0.5 g of a polyether polysiloxane foam stabilizer (OS 50 of Bayer AG)
3.5 g of dimethylbenzylamine,
0.5 g of tetramethylguanidine,
37 g of the compound according to Example 2.
Component B
123 g of the diisocyanate used in Example 7.
The reaction mixture is prepared and worked up as in Example 5. It begins
to foam after 32 seconds. A foam plate 10 mm in thickness can be removed
from the mold after 12 minutes. Its density is 0.51 g/cm.sup.3, its
phosphorus content 2%.
TESTS FOR FIRE RESISTANCE
(1) according to UL-Subj. 94
Total after burning time: 6 seconds;
Classification: UL-VO
(2) csa test
After burning times: 1, 4, 10, 20, 6 seconds;
Classification: passed.
Comparison Example
If the process is carried out as described in Example 7 or 8 but without
the compounds according to the invention, the material passes neither the
fire test according to UL-Subj. 94 nor the CSA test.
EXAMPLE 9
A mixture of
100 parts by weight of a polypropylene glycol having an OH number of 28
which has been started on trimethylolpropane and modified with ethylene
oxide so that it contains 60% of primary hydroxyl end groups
3.1 parts by weight of water,
0.2 parts by weight of diazabicyclo-2,2,2-octane,
0.5 parts by weight of N-methylmorpholine,
0.5 parts by weight of N,N-dimethylethanolamine,
1.0 part by weight of a silicone stabilizer according to the general
Formula:
##STR14##
2.0 parts by weight of the compound described in Example 1 and 45.0 parts
by weight of the isocyanate described below is reacted in a closed mold.
20 Parts of 1,2-propylene glycol are added to a mixture of 225 parts of a
mixture of 80% by weight of 2,4- and 20% by weight of 2,6-tolylene
diisocyanate and 274 parts of 4,4'-diphenylmethane diisocyanate at
60.degree. C and the mixture is reacted inside a metal mold for 30
minutes. After the addition of 1 part of .beta.-phenylethyl-ethylene
imine, the mixture is heated to 130.degree. C. The trimerization reaction
which takes place at this temperature is stopped by the addition of 1 part
of p-toluenesulphonic acid methyl ester after 21/2 hours, when the NCO
content of the reaction mixture is 26.5%.
After dilution with 624 parts of an 80/20 mixture of 2,4- and 2,6-tolylene
diisocyanate, a polyisocyanate is obtained which has an NCO content of
38.4% by weight, a viscosity of 24 cP at 25.degree. C and a refractive
index n.sub.D.sup.50 = 1.5738.
A foam which has the following mechanical properties is obtained.
______________________________________
Gross density (DIN 53420) 34 kg/m.sup.3
Tensile test (DIN 53571) 85 KPa
Elongation at break
(DIN 53571) 150%
Compression test (DIN 53577) 2.3 KPa
Pressure deformation
residue (DIN 53572) 63%
______________________________________
Fire Test According to ASTM-D 1692-68
Assessment: self extinguishing
Average length of burning path: 70 mm
Average extinction time: 44 seconds
* * * * *
|
|
 |
|
|
