CA1051588A - Water impermeable polyurethanes - Google Patents

Abstract

Abstract of the Disclosure - Low density water impermeable polyurethane foams containing alkyl substituents of from 10 to 21 carbon atoms and to a composition and process for preparing hydrophobic urethane foams comprising reacting a mixture of a polyalkylene polyol having reactive hydrogen atoms as determined by the Zerewitinoff method exhibiting a molecular weight of at least 500, at least one hydrophoblc alkyl compound containing from 10 to 21 carbon atoms per active hydrogen atom capable of reacting with an isocyanate, water, at least one gel catalyst, at least one foaming catalyst, and an organlc polylsocyanate.

Description

I~GW(1-103~
,.

16~5~L588 W~TER IMPERMEABLE POLYU~ETHANES
Thls ~nvention relates to novel water impermeable, hydrophobic polyurethane foams and to novel compositions and methods ~or producing such foams.
It is well known that a polyurethane can be prepared by reacting organic poly-functional isocyanates with organic compounds having two or more reactive hydrogen atoms as determined by the Zerewitinoff reaction. When this reaction is conducted under anhydrous conditions~ the resulting polyurethane may be non-porous. If a cellular or foamed product is desired, water and an excess of lsocyanate must be added to the mixture.
When water reacts with the excess isocyanate groups not previously reacted,carbon dioxide is formed and entrapped in the reaction mixture. A cellular or foamed product may also be prepared by including a low boiling solvent such as trichlorofluromethane 9 l trichlorotrifluromethane, methylene chloride and the like. Also low boiling solvents and water may be used in the mixture to form a cellular product. Various materials have been employed as catalysts or activators in the formation of polyurethanes.
The preparation of ~oam from polyurethanes requlres a predetermined control of the blowing or gas forming reaction which liberakes the carbon dioxide. It has been found that the desired foam tlme or rise time should be about 20 to lOO seconds, typically about 70 seconds measured under commercial conditions in environmental temperatures of about 25C. Although many systems ha~e been tried, there is no simple commercial system which will permit the production of water impermeable~
hydrophobic polyurethane foams.

:

~5~L5~3~
It is an object of this invention to provide a water impermeable, hydrophobic foam product based on polyurethane. It is a further object of this invention to form water impermeable, hydrophobic polyurethane for applications where elimination of water penetration is necessary. Other ob-jects will be apparent to those skilled in the art on inspection of the following description.
The present invention provides a process for preparing a water-impermeable polyurethane plastic which comprises mixing: (a) an organic polyisocyanate; (b) a primary or secondary hydroxy-terminated polyalkylene ether having from 2 to 4 hydroxyl groups and a molecular weight from about 500 to 10,000 and having a reactive hydrogen atom as determined by the Zerewitinoff method; and (c) water or a mixture of a low boiling solvent and water, in the presence of: (1) from about 0.005 to about 5 parts of a gel catalyst per part of blow catalyst, wherein said gel catalyst is selected from the group consisting of, Sn(OCORt)2 wherein R~ is a hydrocarbon radical containing up to 17 carbon atoms; and Rl SnXb wherein Rl is as defined above, X is selected from the group chlorides, negative residual organic carboxylic acids RCOO~ or captides RS, alcohols RO, and esters of mercapto acids ROOC(CH2) S wherein R is a hydrogen atom or an aIkyl radical containing up to 17 carbon atoms; (2) from about 0.005 to 5 parts by weight per 100 parts by weight of the polyol of a blow catalyst selected from: tertiar~ amines;
metal soaps of the formula M(OCR") wherein R" is an organic acid radical con~
taining up to 21 carbon atoms, n is a valance of the metal atom, and the me-tal form is selected from the group consisting of antimony, bismuth, arsenic, manganese~ iron, cobalt, nickel, alkali metal (including ammonium), alkaline earth metal, silver~ zinc~ cadmium, aluminum, or lead; and an organotin compound of ~he formttla R~3SnX~ wherein R' is as defined above and X~ is a negative residue from an organic carboxylic acid, a mercaptan, an alcohol, a phenol, or a halogen acid; or a mixture thereof; (3) from about 5 to 70

- 2 -,: . . . ~ . . .
.. .. . , - ~

~051~88 ~
parts by weight of the polyol of a hydrophobic composition comprising at least one hydrophobic organic compound containing at least one active hydrogen and having from 10 to 21 carbon atoms.
The present invention also provides a novel composition suitable for use in the production of water-impermeable polyurethane foams by the re- ;
action of (a) an organic polyisocyanate; (b) a primary or secondary hydroxy-terminated polyalkylene ether having from 2 to 4 hydroxyl groups and a mole-cular weight from about 500 to lO,OOO and having a reactive hydrogen atom as determined by the Zerewitinoff method; and (c) water or a mixture of a low boiling solvent and water, which comprises essentially a hydrophobic composi-tion comprising at least one hydrophobic organic compound containing at least one active hydrogen and having from lO to 21 carbon atoms.
The foaming agent system of this invention provides an easily con- ;
trolled foamillg process. The no~el preferred hydrophobicity impàrting com-pounds are straight chain alcohols exhibiting of from lO to 21 carbon atoms, such as lauryl alcohol, heptadecanol cetyl ilcohol, eicosanol non-adecanol, . , octadecanol, etc. The alkyl compounds may be any compound of the formula ~; ~
. .
(YRZ)n, wherein Y and Z are selected from the group consisting of mercapto, , "~ ',.'3 ! 0 ~ SH, hydroXyl~ -OH, and-o~ 3R4D~ wherein R is a hydrocarbon of at ;~ '~
least about lO carbon atoms and n is an integer of from l to 4. Thus~ when the alkyl compolund containing at least one alkyl group exhibiting from about ~;
lO to about 21 carbon atoms ."-;. '. '~ `.
.. . .
'": ` ' ~ ' ;', ':"j - ,', . -: .. ::
s'i ~ - 2a - ;`- -per active hydrogen atom capable of reacting with an lsocyanate is a mercaptan, the mercaptan may be lauryl mercaptan, undecyl mercaptan, etc. The hydrophobic component is present in an amount from 5 parts to 70 parts by ~eight o~ the organic polyol.
Polyols used in making the polyurethanes of the present invention are primary and secondary hydroxy-terminated polyoxyalkylene ethers having from 2 to 4 hydroxyl groups and a molecular weight o~ ~rom about 500 to 10,000. They are liquids or are capable o~ being lique~ied or melted for handling in the polyurethane foaming apparatus or machine.
Examples o~ polyoxyalkylene polyols include linear and branched polyethers having a plurality o~ ether linkages and containing at least two hydroxyl groups and being substan-tially free from functional groups other than hydroxyl. hmPng the polyoxyalkylene polyols which are useful in the practice of this invention are the polyethylene glycols, the polypropylene glycols, and polybutylene ether glycols. Polymers and copolymers of polyoxyalkylene polyols are also adaptable in the process o~
this invention as well as the block copolymers of ethylene oxide and propylene oxide. Among the copolymers o~ polyoxyalkyl-ene polyols that deserve some special mention are the ethylene oxide, propylene oxide and butylene oxide adducts o~ ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, ~ -tr~ethylene glycol, 2-ethylhexane-diol-1,3~glycerol, 1,2 J 6-hexanetriol~ trimethylolpropane, trimethyolethane, tris(hydroxy-phenyl~ propane, triethanolamine, triisopropanolamine, .
... . ~

10~15138 ethylenediamine, and ethanolamlne. Linear and branched copolyethers of ethylene oxide and propylene oxide are also useful in mak~ng the foamed products of this invention with the preferred ones being those end-blocked with ethylene oxide to provide primary hydroxyl groups in the polymer and having molecular weights of from about 1000 to 5000.
~ Further useful types of polyetherpolyols are block copolymers prepared from propylene oxide and ethylene oxide.
These polyethers can be characterized by the general formulae:
CH~
H(0-CH2-CH2)x(0-CH-CH2)y(0-CH2-CH2)zOH
and (A) CH3 fH3 H(O-CH2-CH2)a(O-CH-CH2 ~ (CH2-CH-O)b(CH~-CH2-O)aH

H(0-CH2-CH2)a(0-fH-CH2)b ~CH2-fH-O)b(CH2-CH2-O)aH
CH3 CH~
(B~
wherein Formula A the total o~ subscripts, x~ y, and z represent positive integers in the range of from 20 to 70 and the total of subscripts a and b of Formula B represent positive integers in the range of ~rom 20 to 100.
Polyethers having a branched chain network are also useful. Such branched chain polyethers are readily prepared ~rom alkylene oxides of the type above described and initiators having a functionality greater than two. Branched polyethers have the advantage of making possible cross linking without the . .

interaction of urea or urethane groups with the isocyanate groups. This has the advantage of making a larger proportion of the isocyanate used available for the evolution of carbon dioxide and the reducing o~ the overall amount of isocyanate that is required in the preparation of the foamed polymer.
Mixtures of polyether polyols can be used.
Examples of these polyoxyalkylene polyols include polypropylene glycols having average molecular weights of 500 to 5,000 and reaction products of propylene oxide with linear diols and higher polyols, said higher polyols when employed as reactants giving rise to branched polyoxyalkylene polyols; and ethylene oxide, propylene oxide copolymers having average molecular weights of 500 to 5,000 in which the weight ratio of ethylene oxide to propylene oxide ranges between 10:90 and 90:10, including reaction product mixtures of ethylene oxide and propylene oxide in the said ratios with linear diols and higher polyols.
Examples of linear diols referred to as reactants with ~-one or more alkylene oxides include ethylene glycol, propylene glyool, 2-ethylhexanediol-1,3 and examples of higher polyols include glycerol, trimethylol propane, 1,2,6-hexane triol, pentaerythritol and sorbitol.
Another class of polymers having termlnal groups that contain reactive hydrogen atoms suitable for reaction with polyisocyana~es are lactone polymers, preferably those exhibiting molecular weights within the range of 500 to 10,000.

~a~5158~3 In the preparation of a cellular polyurethane, water is mixed with the condensation product of an alkylene oxide and an organic polyiso^yanate to produce carbon dioxide which acts as a blowing agent. Many foaming or blowing catalysts may be used to accelerate the formation of cellular polyurethane.
It is a feature of this invention that the synergistic blowing catalyst combination herein noted may be used in connection with a wide variety of gel catalysts including for example dibutyltin dilaurate and stannous 2-ethylhexoate, etc.
In practice of the preferred embodiment of this invention, the preferred gelatin catalyst which may be employed may be selected ~rom the group consisting of Sn(OCOR)2 and R'aSnXb. Other equivalent gelation catalysts may be employed. In the stannous compounds, Sn(OCOR)2, R may be a hydrocarbon residue typically alkyl~ alkenyl, aryl, aralkyl, alkaryl, cycloalkyl, etc. R may, for example, be methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl3 oleyl i.e. 7-heptadecenyl, etc., phenyl, o-, m-, or p-tolyl, naphthyl, cyclohexyl, benzyl, etc. The nature of R
will, o~ course, define the group -OCOR3 when R is methyl, for example, this group may be the acetate group. Preferably, however, the R group will contain at least about 7 carbon atoms and less than about 17 carbon atoms. When R is heptyl, the group -OCOR may be the 2-ethylhexoate group; when R is 7-hepta-decenyl, the group -OCOR is the oleate group, e~c. The preferred compounds which may be employed is stannous 2-ethylhexoatç and stannous oleate.
. ..

. . .- .- ....... , . . ,-: . . . . .

In the organotin compounds R'aSnXb, R' may be the same as R. Preferably R' will be a hydrocarbon residue, typically alkyl, alkenyl, aryl, alkaryl, aralkyl, cycloalkyl, etc. R' may be, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, oleyl, i.e. 7-heptadecenyl, etc., phenyl, o-, m-, or p-tolyl, naphthyl, cyclohexyl~ benzyl, etc. The sum of a and b will be 4, and either of a and b may be 1, 2, and'3.
The preferred R' group is the n-butyl group C4H9-.
In the organotin compounds R'aSnXb, X may be selected from the group consisting o~ chlorides and the negative residual portions of organic carboxylic acids RCOO-, mercaptides RS~, alcohbls RO-, esters of mercaptoacids ROOC(CH2~nS whe`rein R may be hydrogen or the other residues' hereinbefore'noted; etc.
Typical specific residual portions may include the-2-ethylhexoate the lauryl mercaptide, the methoxide, and the isooctyl thiogly-colate. ' ~he pre~erred organotin compounds R'aSnXb' may be those wherein a and b are 2; e.g. dibutyltin dilaurate and dibutyltin di-2-ethylhexoate.
In the practice o~ this invention, the gel catalyst and the novel blowing catalyst combination may be present in ratio o~ 0.01 to 5 parts, say 1 part of the former per part of the latter. In one pre~`erred embodiment, when the blowing catalyst combination o~ this invention is used with stannous 2-ethylhexoate as the gel catalyst, the ratio will be approximate y 1. ' ':, - - . - - . , .-, . . , ., .:

:105:~5i88 Preferably the catalyst mixture will be present in catalytic amount corresponding to 0.01 to 5, say o.6 par~s by weight per 100 parts o~ polyol. Preferably, the blowing catalyst will be present in a catalykic amount corresponding to 0.005 to 4.95, say 0.3 parts by weight per 100 parts of polyol, and the gel catalyst will be present in catalytic amount corresponding to 0.005 to 4.2 parts~ say 0.3 parts by weight per 100 parts of polyol.
It is also a feature of this invention that the combination herein noted may be used in connection with a wide variety of blowing or foaming catalystsO These may include tertiary amines, metal soaps wherein the metal may be antimony, bismuth, arsenic, manganese, iron, cobalt, nickel, alkall metal (lncluding ammonium), alkaline earth metal, silver~ zinc, cadmium aluminum, or lead, or organotin compounds having the formula R'3SnX' wherein R' is hydrocarbon and X' is selected ~rom the group consisting of the negative residual portlon of an organic carboxyllc acid, a mercaptan, an alcohol, a phenol, and a halogen acid.
Typlcal tertiary amines whlch may be employed as blowlng catalysts include N-alkyl morpholines, e.g. N-methyI
morpholine, N-ethyl morphollne (NEM) and cyclic triethylene diamine includin~, e.g. that which is sold under the trademark DABC0. Particularly pre~erred tertiary amine bIowing catalysts may contain N-ethyl morpholine or cyclic triethylene diamine or mixtures ~hereof~ the mixtures containing say about 1-2 parts by weight of cyclic triethylene diamine per 3 parts of N-ethyl - :: - -. -¦ morphol~ne. Tertlary amlne blowing catalysts may be particularly ¦ desirable when fast rlse times are desired.
Typical metal soaps which may be employed as blowing l catalysts include compounds having the formula M(OOCR")n ¦ wherein M is selected from the group consisting of antimony, bismuth, arsenic, manganese, iron, cobalt, nickel, silver~
zinc, cadmium, aluminum, and lead, R" is a hydrocarbon group and n is a small whole integer corresponding to the valence of M, typically 1, 2, 3, etc. Preferably n is 1 and the acid from which the soap is derived is monobasic. Among the hydrocarbon groups which may be represented by R", the following may be particularly noted: aliphatic or cycloaliphatic groups such as alkyl, alkenyl, etc. and corresponding cyclic groups sueh as cycloalkyl, etc.; an aryl group such as phenyl, subs~ituted phenyls, naphthyl, etc.; an aralkyl group such as benzyl, styryl, cinnamyl, etc.; an alkaryl group such as tolyl, xylyl, etc.; a eycloaliphatic group such as a naphthenie group;
etc. Other equivalent groups may be employed. In a pre~erred embodiment, R" may be an alkyl group having less than about 21 carbon atoms. Typieal of the acids from which the soaps may be prepared may be aeetie aeid, propionic acid~ butyric acid, caproic acid, eaprylie acld, caprie aeid, stearie acid, oleic aeid, ete. Naphthenie acid may be employed. The commercially-oecurring mixture of acids known as "tall oil fatty aeids" may ` be employed. When the metal M is antimony, bismuth or arsenie, the pre~erred R" group may be an aliphatic group having 6-21 carbon atoms. Typical preferred aeids from whieh these ... ~ _ g _ ~051S~318 particular soaps may be prepared include 2-ethyl hexoic acid, pelargonic acid, oleic acid, tetrachlorobenzoic acid, cyclohexyl carboxylic acid, and commercially-occurring mixture of tall oil fatty acids.
Specific metal soaps include: antimony tri-2-ethyl hexoate; antimony tripelargonate; arsenic trioleate; antlmony tritallate; bismuth tri-2-ethylhexoate; arsenic tripelargonate;
antimony tri(tetrachlorobenzoate); antimony tri(cyclohexyl- .
carboxylate); bismuth trioleate; ferric stearate; manganous iO stearate; cobaltous stearake; cobaltous naphthenate; ferric linoleate; manganous linoleate; ferrous stearate; nickel stearate; . :
calcium naphthenate; ammonium stearate; dimethylammonium stearate; :. :
trimethylammonium stearate; calcium stearate; magnesium stearate;
. barium stearate; lithium stearate; sodium stearate; strontium stearate; potassium oleate; ammonium tallate; strontium 2~ethyl-hexoate; lead naphthenate; æinc naphthenate; aluminum monostearate ;
aluminum distearate; aluminum trlstearate; plumbous ~tearate;
plumbous stëarate (basic); zinc stearate; cadmium stearate, silver stearate; silver acetate; l~ad pelargonate. Preferred metal soaps include: antimony tritallate; manganese linoleate; . .
. ferrous stearate; nickel stearate; calcium naphthenate; barium stearate; sodium stearate; calcium stearate; zinc naphthenate;
plumbous stearate; and aluminum distearate. Most highly preferred metal soaps include: manganese linoleate; calcium naphthenate;
cadmium stearate; and particularly antimony tritallate.

_ 10 -10~1588 ¦ In the practice o~ this invention, according to certain ¦ of i~s aspects/ when a blowing catalyst is employed, the curing ¦ catalysts may be present in a ratio of 0 1-5 parts by weight to ¦ 1 part by weight of blowing catalyst, preferably 0.5-2.5 to 1. ~, ¦ Preferably the catalyst mixture will be present in catalytic amount corresponding to 0.01 to 5, say o.6 parts by weight per 100 parts of polyol. Preferably, the blowing catalyst will be present in a catalytic amount corresponding to 0.005 to 4.95, say 0.3 parts by weight per 100 parts of polyol, and the gel catalyst will be present in a catalytic amount corresponding to 0.005 to 4.2 parts, say 0.3 parts by weight per 100 parts of polyol.
The process of this invention is particularly adapted for making both cellular polyurethanes and non-porous poly-urethane plastics. The hydrophobic compositions provided by this lnvention are efficacious in preparing water-impermeable urethane products by casting processes or by processes in which `
a millable gum is ~ormed. In processes of this type, the condensation product of an alkylene oxide is reacted ~ith an organic polyisocyanate and a at least one alkyl compound exhibiting from about 10 to about 21 carbon atoms per active hydrogen atom capable of reacting with an isocyanate.
A variety o~ organic polyisocyanates may be used in the practice of this invention although diisocyanates are preferred in many formulations. Suitable polyfunctlonal isocyanates include alkylene diisocyanates such as hexamethylene dilsocyanates~ and decamethylene diisocyanates, tolylene ' ~, '' ' ` ':` : " ' ' ' . . - '` " ` ' 10515~8 diisocyanates, naphthalene diisocyanates, 4,4'-diphenylmethane diisocyanates, isomers or mixtures of any of these.
Triisocyanates typically obtained by reaction with 3 moles of an arylene diisocyanate with l mole of a triol, e.g. the reaction products formed from 3 moles of tolylene diisocyanate and 1 mole of hexane triol may be employed. A preferred polyisocyanate ls the mixture of 80% 2,4-tolylene diisocyanate and 20% 2,6-tolylene diisocyanate.
The term "isocyanates" is used herein to refer to polyisocyanates and to polyisothiocyanates, respecti~ely, including particularly diisocyanates and diisothiocyanates.
While the invention has been described specifically with referenc~
to the reaction of certain diisocyanates, it is generically applicable to the reaction of any compound containing two or more -N=C=G groups in which G is oxygen or sulfur. Compounds within this generic definition include polyisocyanates and po,lyisothiocyanates of the general formula RtNcG)x .
in which x is two or more and R can be alkylene, substituted alkylene, arylene, substituted arylene, a hydroaarbon or substituted hydrocarbon containing one or more aryl -NCG bonds and one or more alkyl -NCG bonds, a hydrocarbon or substituted hydrocarbon containing a plurality of either aryl -NCG or alkyl -NCG bonds. R can also include radicals such as -R-Z-R
~here Z may be any divalent moiety such as -0-, -O-R-O-, -C0-, -C2-~ -S-~ -S-R-S-, -SO2-, etc. Examples of such compounds ~ '1' .~ . , . . ~ . .

I ~OS~S8~
include hexamethylene diisocyanate, 1,8~diisocyanate-p-methane, ¦ xylylene diisocyanates, (OCNCH2CH20CH2)~ methyl-2,4-diiso-cyanate-cyclohexane, phenylene diisocyanates, tolylene diiso-l cyanates, chlorophenylene dilsocyanates, diphenylmethane-4,4'-¦ diisocyanate, naphthalene-1,5-diisocyanate, triphenylmethane-4, 4',4"-triisocyanate, xylene-~,a'-diisothiocyanate, and isopropylbenzene-a,4-diisocyanate.
Further included are dimers and trimers o~ isocyanates and diisocyanates and polymeric diisocyanates o~ the general formulae (RNCG)X and CR(NCG)X] Y : .

in which x and y are two or more, as well as compounds of the :
. general ~ormula . M(NCG)X

in which x is two or more and M is a di~unctional or poly-functional atom or group. Exampies o~ this type include ethylphosphonic diisocyanate, C2H~P(O)(NCO)2, phen~lphosphonic diisocyanate, C6H~P(NCO)2; compounds containing a _Si-NCG group, isocyanates derived from sulfonamides (RSO2NCO), cyanic acid, ~0 and thiocyanic acid.
Substances having two or more active hydrogen atoms determined by the Zerewitino~ method operative in the practice of this invention are those organic compounds having two or more reactive hydrogen atoms which react with organic poly-~unctional isocyanates to give urethane polymers. The amount of isocyanate employed generally ranges ~rom 1 to 7 equivalents prererably 2 to 6 equivalents, per equivalent o~ polyether. :

. . . .

~os~s~
The reaction of excess diisocyanate with a poly-oxypropylene glycol produces a polymer having terminal iso-cyanate groups. I~en it is desired to form a foam, the mixture of the isocyanate-modified polyether reacts through the isocyanate groups with a chain-extending agent containing active hydrogen such as water. This involves several reactions that proceed simultaneously including the reaction between the isocyanate groups and wa~er to form urylene links (-NHCONH-) and carbon dioxide, as well as the reaction of the urylene links so formed with unreacted isocyanate groups to form biuret cross links. Depending upon the desired density of the urethane foam and the amount of cross linking desired, the total isocyanate equivalent to the active hydrogen equivalent should be such as to provide a ratio of 0.8 to 1.2 e~uivalents of isocyanate per equivalent of ac~ive hydrogen, and preferably a ratio of about 0.9 to 1.1 equivalents.
Cell modifying agentsJ e.g. silicones such as tri-methyl end-blocked dimethyl polysiloxanes may also be used in the practice of this invention.
Other well known constituents can be added to the poly-urethane foam recipe such as clay, talc, Ti02, silica and hydrated ~`
silica, CaC03, metal chromates, barytes, phthalocyanine green or blue pigments, red iron oxide, conventional stabilizers, carbon black, dyes, toners, epoxidized soy bean oil ~Paraplex G-62-trademark), epoxides (Epon 828-trademark), ~ricresyl phosphate, antioxidants, fungicides, bacteriostats and the like. These constituents can " . . . : . . ~
i , ~ . . - . - .

be added in various amounts to the foaming ingredlents to achieve the desired properties in the resultant flexible, low density foams. `
The preparation of the polyurethane foams of the present invention can be formed by a process known in the art as the "one-shot" process by a two step process involving, first, the preparation of a "prepolymer," the well known "semiprepolymer"
or "quasi-prepolymer" technique. There all or a portion of the polyol is reacted with all of the organic polyisocyanate, providing a reaction product which contains a high percentage free isocyanate groups and which is reacted with the remaining portion of the hydroxyl-terminated polyol or a crosslinker, together with water, catalysts, and metal oxides to ~orm a rubbery, cellular, elastic product.
The following examples are intended to illustrat;e more fully but not to limit the invention~ which is properly delineated in the claims.
.
.

105~58~ ~

Practice of this invention according to a speci~ic embodiment may be observed by ~orming a typical one shot poly-ether flex~ble foam by mixing the ~ollowing components:
Part A
1. Amine based polyoxypropylene 2,960 parts polyether polyol with a M~ of about 3600 and capped with ethyleneoxide having an OH
number o~ about 62.
2. A C12 to C13 linear primary 592 parts alcohol.

3. Carbon black paste. 65 parts

4. Dibutyltindilàurate 3 parts

5. Triethylenediamine 1.5 parts

6. Dimethyl polysiloxane ~luid 1 part

7. Water 37 parts Part B
1. Polymethylene polyphenylisocyanate 1,464 parts having an equivalent weight of about ` 133.
Part A was mixed with Part B with rapid stirring for several seconds and poured into a suitable mold. The mass swelled to form a cellular polymer. A~ter the mass has cured, a 1" thick section o~ ~oam was sliced ~rom the bun and a "U" shaped section was cut having about a 1 square inch cross section. The sample was compressed about 50% between two plexiglass plates and water ` ' ' , ~ 3S~5~8 poured therein. It was observed that the water makes a high contact angle with the foam sur~ace. .~fter several hours it was observed that water has not passed through the foam.

The process of the foregoing example was used except that the composition was comprised of the following mixture of components:
Part A
l. ~ polyoxypropylene polyol containing 690 parts polystyrene polyacrylonitrile and capped with oxyethylene having an OH
number of about 27.
2. A C13 to C14 linear primary alcohol 80 parts 3. Carbon black paste 15 parts 4. Dibutyltindilaurate 0.5 parts 5. Bis(2-dimethylaminoethyl) ether2 parts 6. D~methylpolysilo~ane fluid0.05 parts 7. A silicone glycol copolymer0.15 parts

8. ~ater 10.7 parts Part B
l. Polymethylene polyphenylisocyanate 270 parts having an e~uivalent weight o~ about 133.
Part A was mixed with Part B as described in Example l. Testing of the foam for resistance to water penetratlon as described in Example 1 yielded results that demonstrated unusually hlgh hydrophobic properties.

. ~ . . . .

¦ Although this invention has been illustrated by ¦ reference to specific embodiments, modifications thereof which ¦ are clearly within the scope of the invention will be apparent ¦ to those skilled ln the art.

Claims (20)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for preparing a water-impermeable polyurethane plastic which comprises mixing:
(a) an organic polyisocyanate;
(b) a primary or secondary hydroxy-terminated polyalkylene ether having from 2 to 4 hydroxyl groups and a molecular weight from about 500 to 10,000 and having a reactive hydrogen atom as determined by the Zerewitinoff method; and (c) water or a mixture of a low boiling solvent and water, in the presence of:
(1) from about 0.005 to about 5 parts of a gel catalyst per part of blow catalyst, wherein said gel catalyst is selected rom the group con-sisting of;
Sn(OCOR')2 wherein R' is a hydrocarbon radical containing up to 17 carbon atoms; and R'aSn X wherein R' is asirdefined above, X is selected from the group chlorides, negative residual organic carboxylic acids RCOO, or captides RS, alcohols RO, and esters of mercapto acids ROOC(CH2)nS wherein R is a hydrogen atom or an alkyl radical containing up to 17 carbon atoms;
(2) from about 0.005 to 5 parts by weight per 100 parts by weight of the polyol of a blow catalyst selected from: tertiary amines; metal soaps of the formula M(OCR")n wherein R" is an organic acid radical containing up to 21 carbon atoms, n is a valance of the metal atom, and the metal atom is selected from the group consisting of antimony, bismuth, arsenic, manganese, iron, cobalt, nickel, alkali metal (including ammonium), alkaline earth metàl, silver, zinc, cadmium, aluminum, or lead; and an organotin compound of the formula R'3SnX wherein R' is as defined above and X' is a negative residue from an organic carboxylic acid, a mercaptan, an alcohol, a phenol, or a halogen acid;
or a mixture thereof (3) from about 5 to 70 parts by weight of the polyol of a hydro-phobic composition comprising at least one hydrophobic organic compound containing at least one active hydrogen and having from 10 to 21 carbon atoms.

2. A process according to claim 1 for preparing a water-impermeable cellular polyurethane wherein the hydrophobic organic composition comprises a hydrophobic alkyl compound containing at least one active hydrogen and having from 10 to 21 carbon atoms which is capable of reacting with an isocyanate.

3. The process of making water-impermeable cellular polyurethane as claimed in claim 2 wherein the alkyl compound is a mercaptan.

4. The process of making water-impermeable cellular polyurethane as claimed in claim 2 wherein the alkyl compound is a straight chain alcohol.

5. The process of making water-impermeable cellular polyurethane as claimed in claim 2 wherein said blowing catalyst includes tertiary amines.

6. The process of making a water-impermeable cellular polyurethane as claimed in claim 2 wherein said blowing catalyst includes cyclic triethylene diamine.

7. The process of making a water-impermeable cellular polyurethane as claimed in claim 2 wherein said blowing catalyst is a metal soap.

8. The process of making a water-impermeable cellular polyurethane as claimed in claim 2 wherein said blowing catalyst is dibutyltin dilaurate.

9. The process of making a water-impermeable cellular polyurethane as claimed in claim 2 wherein said blowing catalyst is an organotin compound having the formula R'3SnX' wherein R' and X' are as defined in claim 1.

10. The process according to claim 1 of making a water-impermeable polyurethane plastic wherein the hydrophobic organic composition comprises a hydrophobic straight chain alcohol having from 10 to 21 carbon atoms and at least one active hydrogen atom.

11. The process of making a water-impermeable polyurethane plastic according to claim 1 wherein the hydrophobic composition comprises a mixture of at least two hydrophobic long chain alcohols.

12. The process according to claim 1 for making water-impermeable cellular polyurethane which comprises reacting 100 parts by weight of a substance exhibiting Zerewitinoff active hydrogen atoms, 5 to 50 parts by weight of an organic polyfunctional isocyanate, 0.5 to 10 parts by weight of water, 0.005 to 4.95 parts by weight of a blowing catalyst, about 0.005 to 4.2 parts by weight of a gel catalyst and 5 to 70 parts by weight of a hydrophobic organic composition comprising at least one hydrophobic straight chain alcohol having from 10 to 21 carbon atoms.

13. A novel composition suitable for use in the production of water-impermeable polyurethane foams by the reaction of (a) an organic polyisocyanate;
(b) a primary or secondary hydroxy-terminated polyalkylene ether having from 2 to 4 hydroxyl groups and a molecular weight from about 500 to 10,000 and having a reactive hydrogen atom as determined by the Zerewitinoff method; and (c) water or a mixture of a low boiling solvent and water, which comprises essentially a hydrophobic composition comprising at least one hydrophobic organic compound containing at least one active hydrogen and having from 10 to 21 carbon atoms.

14. A composition according to claim 13 wherein the organic hydro-phobic composition comprises at least one hydrophobic alkyl compound of from 10 to 21 carbon atoms which is capable of reacting with an isocyanate.

15. A composition according to claim 13 wherein the organic hydro-phobic composition comprises at least one hydrophobic straight chain alcohol having from 10 to 21 carbon atoms.

16. A composition according to claim 13, further including per 5 to 70 parts of said organic hydrophobic composition:
(a) from about 0.005 to about 5 parts of a blow catalyst selected from tertiary amines; metal soaps of the formula M(OCR")n wherein R" is an organic acid radical containing up to 21 carbon atoms, n is a valance of the metal atom, and the metal atom is selected from the group consisting of antimony, bismuth, arsenic, manganese, iron, cobalt, nickel, alkali metal (including ammonium), alkaline earth metal, silver, zinc, cadmium, aluminum, or lead; and an organotin compound of the formula R'3SnX' wherein R' is as defined above and X' is a negative residue from an organic carboxylic acid, a mercaptan, an alcohol, a phenol, or a halogen acid;
or a mixture thereof, and (b) per part of said blow catalyst a gel catalyst selected from the group consisting of; Sn(OCOR')2 wherein R' is a hydrocarbon radical con-taining up to 17 carbon atoms; and R'aSnXb wherein R' is as defined above, X is selected from the group chlorides, negative residual organic carboxylic acid RCOO, or captides RS, alcohols RO, and esters of mercapto acids ROOC(CH2)nS wherein R is a hydrogen atom or an alkyl radical containing up to 17 carbon atoms;

17. A novel water-impermeable polyurethane plastic according to claim 13 which comprises a cellular polyurethane, and a hydrophobic amount of a hydrophobic com-position comprising at least one hydrophobic organic compound containing at least one active hydrogen and having from 10 to 21 carbon atoms.

18. A novel water-impermeable polyurethane according to claim 17 wherein the hydrophobic composition comprises at least one hydrophobic alkyl compound containing at least one active hydrogen and having from 10 to 21 carbon atoms.

19. A novel water-impermeable polyurethane according to claim 17 wherein the hydrophobic composition comprises at least two hydrophobic alcohols having at least one hydroxyl group per alcohol, each alcohol having from 10 to 21 carbon atoms.

20. A novel composition according to claim 16 which comprises a blowing catalyst containing about 1-2 parts by weight of cyclic triethylene diamine, about 3 parts by weight of N-ethyl morpholine, a gel catalyst and a hydrophobic composition comprising at least one alkyl compound having from about 10 to about 21 carbon atoms per active hydrogen atom capable of reacting with an isocyanate.