CA2218254A1 - Process for preparing a storage-stable mixture of polyisocyanate and phosphate - Google Patents
Process for preparing a storage-stable mixture of polyisocyanate and phosphate Download PDFInfo
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- CA2218254A1 CA2218254A1 CA002218254A CA2218254A CA2218254A1 CA 2218254 A1 CA2218254 A1 CA 2218254A1 CA 002218254 A CA002218254 A CA 002218254A CA 2218254 A CA2218254 A CA 2218254A CA 2218254 A1 CA2218254 A1 CA 2218254A1
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
- C08G18/776—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur phosphorus
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
- C08G18/38—Low-molecular-weight compounds having heteroatoms other than oxygen
- C08G18/3878—Low-molecular-weight compounds having heteroatoms other than oxygen having phosphorus
- C08G18/3882—Low-molecular-weight compounds having heteroatoms other than oxygen having phosphorus having phosphorus bound to oxygen only
- C08G18/3885—Phosphate compounds
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polyurethanes Or Polyureas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Materials For Medical Uses (AREA)
- Paints Or Removers (AREA)
Abstract
A process for preparing a liquid, storage-stable composition containing an organic polyisocyanate and an acid phosphate is disclosed. The process includes the steps of (1) heating a mixture of a polyisocyanate and an acid phosphate at a temperature in the range of from 60 ~C to 190 ~C for a time such that no phase separation occurs upon cooling the reaction mixture to ambient temperature, the mixture containing dissolved gases; and (2) subjecting the mixture to a negative pressure sufficient to remove at least a portion of the dissolved gases therefrom. The negative pressurization significantly slows the rate of carbon dioxide evolution thereafter and therefore enables much longer term storage-stability than is obtainable when the negative pressurization step is not performed, beacause it reduces problems associated with pressurization of containers.
Description
CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 MIXTURE OF POLYISOCYANATE AND PHOSPHATE
This invention relates to the field of polyisocyanates and, more particularly, to the 5 field of storage-stable polyisocyanate/phosphate mixtures.
It is known that mixtures of polyisocyanates and pho~,hdLes are useful for various purposes. For example, such can be used as binder resins having releasing p. ope, lies for wood composite materials. These polyisocyanate cc"-,posi lions are particularly useful as binders in the p(epa. dlion of particle boards and similar materials. See, for example, U.S. Patents 10 3,428,S92; 3,440,189; 3,557,263; 3,636,199; 3,870,665; 3,919,017; and 3,930,110. Whilesome of these mixtures can be made relatively storage-stable in that they do not deposit solids or separate into two liquid phases during relatively short-term storage (see, for example, U.S
Patent4,258,169,Re.31,703,andJP618469),theyunfortunatelystilltendtoproducecarbondioxide over time which can present problems during longer term storage The carbon dioxide prod uction may be handled via use of release valves for large scale shi pment, as for example via railcars, but the problem is more difficult when shipment is on a small scale, such as in drums or smaller containers, which generally are not fitted with relief valves, and which therefore may burst due to the pressurization.
The present i nvention solves the probiem of pressurizatlon of containers. It Is an 20 improvement i n a process for producing a storage-stable mixture of a polyisocyanate and an acid phosphate, wherein dissolved gases are present, comprising subjecting the mlxture to a negative pressure for a time sufficient to remove at least a portion of the dissolved gases therefrom. Fl ere.dbly the amount of dissolved gases is reduced by at least 10 percent by weight. It has been found that this evacuation, which is preferably carried out at a vacuum 25 pressure of less than 50 mm Hg (2 inches Hg), for a time sufficient to remove at least 90 percent of the dissolved gases in the mixture, more preferably at least 99 percent, results in a mixture which, thereafter, shows markedly decreased gas production. The invention ll ~e~ ~rore reduces or eliminates problems associated with pressurization of smaller containers used to ship or store the mixture.
The polyisocyanate/phosphorus-containing compound mixtures which are treated in the present invention can be prepared from a variety of materials and via a variety of routes. For example, in one embodiment of the present invention the starting material includes one or more phosphorus-containing compounds formed in situ, which function as a release agent when the material is used in formulations which contact certain types of metal 35 surfaces. It is prepared starting with a polyisocyanate and an acid phosphate. This is preferably a mixture of an organic polyisocyanate and from 1 to 20 parts, per 100 parts by weight of the CA 022182~4 1997-10-14 W O96/33231 pcTrus96lo4l2o polyisocyanate, of an acid phosphate selected from the group consisting of acid pho,,uhaLes having the formula:
X X
1' 1 RX-P-OH and (RX)2P-OH
(I) (II) and mixtures of two or more of the acid phosphates, wherein each R is independently selected from the group consisting of alkyl having at least 3 carbon atoms, alkenyl having at least 3 10 carbon atoms, aryl, aryl substituted by at least one alkyl group, alkyl substituted by at least one acyloxy group, wherein the acyl group is the residue of an aliphatic ,.,onocdrl,oxylic acid having at least 2 carbon atoms, and Rl--( ~--FH--fH ) m A B
wherein R1 is selected from the group consisting of alkyl, aryl, and aryl substituted by at least one alkyl, one of A and B rep. ese"l~ hydrogen and the other is selected from the group consisting of hydrogen, methyl, chloromethyl and 2,2,2-trichloroethyl; X is chalcogen selected 20 from the group consisting of oxygen and sulfur; and m is a number having an average value of 1 to 25.
In defining the starting materials above, the term ~alkyl having at least 3 carbon atoms" means a saturated monovalent aliphatic radical, straight chain or branched chain, which has the stated minimum number of carbon atoms in the molecule. Illustrative of such 25 groups are propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl, as well as those having many more carbon atoms such as triacontyl, pentatriacontyl, including isomeric forms thereof. The term "alkyl ~ when used without the above carbon atom limitation is also inclusive of methyl and ethyl.
The term nalkenyl having at least 3 carbon atomsn means a monovalent straight 30 or branched chain aliphatic radical containing at least one double bond, and having the stated minimum number of carbon atoms in the molecule. Illustrative of such groups are allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, heneicosenyl, docosenyl, tricosenyl, pentacosenyl, triacontenyl, pentatria-contenyl, 35 including isomeric forms thereof.
The term "aryln means the monovalent radical obtained by removing one nuclear hydrogen atom from an aromatic hydrocarbon. Illustrative of aryl are phenyl, naphthyl, CA 022182~4 1997-10-14 W O96/33231 PCTnUS96104120 biphenyl, triphenyl. The term ~aryl substituted by at least one alkyl~ means an aryl radical, as above defined, carrying at least one alkyl (as above defined) substituent. Illustrative of such are tolyl, xylyl, butylphenyl, octylphenyl, nonylphenyi, decyiphenyl, decyltolyl, octadecylphenyl.
The term ~aliphatic monocarboxylic acid having at least 2 carbon atoms~ ;s inclusive of any alkanoic or alkenoic acid having the stated minimum number of carbon atoms ~, 5 Illustrative of such acids are acetic, propionic, butyric, hexanoic, octanoic, lauric, stearic, oleic, undecylenic, dodecylenic, isoc.oLonic, palmitic.
Each of the groups R and R1 in the formulae (I) and (Il) set forth above can optionally be substituted by one or more inert substituents, i.e., substituents which do not contain active hydrogen atoms and which are therefore unreactive in the pre~ence of the 10 polyi.ocyanate. Illustrative of such inert substituents are alkoxy, dialkylmercapto, alkenyloxy, dialkenylmercapto, chloro, bromo, iodo, fluoro, cyano.
The acid phosphates of the formulae (I) and (Il) are, for the most part, well-known in the art, and can be prepared by methods well-known in the art. For example, the acid phosphates (I) and (Il) are obtained by reaction of the cc,. Iesponding alcohol or thiol R-XH, 5 v,~l .e. ei n R and X are as hereinbefore defined, with phospl1c . us pentoxide or phos~uhorus oxysulfide using the procedures described by Kosolapof, O. ydnopho~,~,horus Compounds, John WileyandSons, Inc (NewYork, 1950),pp.220-221. Thisreactiongivesrisetoamixtureofthe mono- and di-acid phosphates, which mixture can be separated, if desired, for example by fractional crystallization of the barium and like salts as described in the above cited ~ere.ence.
20 The individual acid phosphates in the mixture of the mono- and di-acid phosphates obtained in accordance with the above reaction can be employed as starting materials in the process of the invention.
It is possible to convert acid phosphates, having the formula (I) and (Il) above, to a product containing the corresponding py. ophos~hates and their sulfur-containing analogues, 25 such as thiophosphates and pyrophos~.holl .iolates, by heating the acid phosphates in the presence of an organic polyisocyanate, with or without any other reactant such as phosphorus oxychloride, phosgene and the like. If the conditions of heating are carefully controlled as described herein, the resulting product is a homogeneous liquid which can be stored for prolonged periods without any tendency to undergo phase separation.
The fact that there are any conditions at all which could lead to the formation of a phase-stable product was, prior to disclosure in, for example, U.S. 4,258,169, Re. 31,703 and JP
618469,surprisingtothoseskilledintheart. Ithadpreviouslybeenexpectedthatthereaction of an acid phosphate of the type shown in formulae (I) or (Il) with an organic isocyanate would proceed in accordance with the following equation in which R has the significance defined 35 above and R' represents the residue of the organic isocyanate, which latter is shown as monomeric for the sake of si mpl i city:
CA 022182~4 1997-10-14 W O96/33231 PCTnUS96/04120 O O O
This invention relates to the field of polyisocyanates and, more particularly, to the 5 field of storage-stable polyisocyanate/phosphate mixtures.
It is known that mixtures of polyisocyanates and pho~,hdLes are useful for various purposes. For example, such can be used as binder resins having releasing p. ope, lies for wood composite materials. These polyisocyanate cc"-,posi lions are particularly useful as binders in the p(epa. dlion of particle boards and similar materials. See, for example, U.S. Patents 10 3,428,S92; 3,440,189; 3,557,263; 3,636,199; 3,870,665; 3,919,017; and 3,930,110. Whilesome of these mixtures can be made relatively storage-stable in that they do not deposit solids or separate into two liquid phases during relatively short-term storage (see, for example, U.S
Patent4,258,169,Re.31,703,andJP618469),theyunfortunatelystilltendtoproducecarbondioxide over time which can present problems during longer term storage The carbon dioxide prod uction may be handled via use of release valves for large scale shi pment, as for example via railcars, but the problem is more difficult when shipment is on a small scale, such as in drums or smaller containers, which generally are not fitted with relief valves, and which therefore may burst due to the pressurization.
The present i nvention solves the probiem of pressurizatlon of containers. It Is an 20 improvement i n a process for producing a storage-stable mixture of a polyisocyanate and an acid phosphate, wherein dissolved gases are present, comprising subjecting the mlxture to a negative pressure for a time sufficient to remove at least a portion of the dissolved gases therefrom. Fl ere.dbly the amount of dissolved gases is reduced by at least 10 percent by weight. It has been found that this evacuation, which is preferably carried out at a vacuum 25 pressure of less than 50 mm Hg (2 inches Hg), for a time sufficient to remove at least 90 percent of the dissolved gases in the mixture, more preferably at least 99 percent, results in a mixture which, thereafter, shows markedly decreased gas production. The invention ll ~e~ ~rore reduces or eliminates problems associated with pressurization of smaller containers used to ship or store the mixture.
The polyisocyanate/phosphorus-containing compound mixtures which are treated in the present invention can be prepared from a variety of materials and via a variety of routes. For example, in one embodiment of the present invention the starting material includes one or more phosphorus-containing compounds formed in situ, which function as a release agent when the material is used in formulations which contact certain types of metal 35 surfaces. It is prepared starting with a polyisocyanate and an acid phosphate. This is preferably a mixture of an organic polyisocyanate and from 1 to 20 parts, per 100 parts by weight of the CA 022182~4 1997-10-14 W O96/33231 pcTrus96lo4l2o polyisocyanate, of an acid phosphate selected from the group consisting of acid pho,,uhaLes having the formula:
X X
1' 1 RX-P-OH and (RX)2P-OH
(I) (II) and mixtures of two or more of the acid phosphates, wherein each R is independently selected from the group consisting of alkyl having at least 3 carbon atoms, alkenyl having at least 3 10 carbon atoms, aryl, aryl substituted by at least one alkyl group, alkyl substituted by at least one acyloxy group, wherein the acyl group is the residue of an aliphatic ,.,onocdrl,oxylic acid having at least 2 carbon atoms, and Rl--( ~--FH--fH ) m A B
wherein R1 is selected from the group consisting of alkyl, aryl, and aryl substituted by at least one alkyl, one of A and B rep. ese"l~ hydrogen and the other is selected from the group consisting of hydrogen, methyl, chloromethyl and 2,2,2-trichloroethyl; X is chalcogen selected 20 from the group consisting of oxygen and sulfur; and m is a number having an average value of 1 to 25.
In defining the starting materials above, the term ~alkyl having at least 3 carbon atoms" means a saturated monovalent aliphatic radical, straight chain or branched chain, which has the stated minimum number of carbon atoms in the molecule. Illustrative of such 25 groups are propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl, as well as those having many more carbon atoms such as triacontyl, pentatriacontyl, including isomeric forms thereof. The term "alkyl ~ when used without the above carbon atom limitation is also inclusive of methyl and ethyl.
The term nalkenyl having at least 3 carbon atomsn means a monovalent straight 30 or branched chain aliphatic radical containing at least one double bond, and having the stated minimum number of carbon atoms in the molecule. Illustrative of such groups are allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, heneicosenyl, docosenyl, tricosenyl, pentacosenyl, triacontenyl, pentatria-contenyl, 35 including isomeric forms thereof.
The term "aryln means the monovalent radical obtained by removing one nuclear hydrogen atom from an aromatic hydrocarbon. Illustrative of aryl are phenyl, naphthyl, CA 022182~4 1997-10-14 W O96/33231 PCTnUS96104120 biphenyl, triphenyl. The term ~aryl substituted by at least one alkyl~ means an aryl radical, as above defined, carrying at least one alkyl (as above defined) substituent. Illustrative of such are tolyl, xylyl, butylphenyl, octylphenyl, nonylphenyi, decyiphenyl, decyltolyl, octadecylphenyl.
The term ~aliphatic monocarboxylic acid having at least 2 carbon atoms~ ;s inclusive of any alkanoic or alkenoic acid having the stated minimum number of carbon atoms ~, 5 Illustrative of such acids are acetic, propionic, butyric, hexanoic, octanoic, lauric, stearic, oleic, undecylenic, dodecylenic, isoc.oLonic, palmitic.
Each of the groups R and R1 in the formulae (I) and (Il) set forth above can optionally be substituted by one or more inert substituents, i.e., substituents which do not contain active hydrogen atoms and which are therefore unreactive in the pre~ence of the 10 polyi.ocyanate. Illustrative of such inert substituents are alkoxy, dialkylmercapto, alkenyloxy, dialkenylmercapto, chloro, bromo, iodo, fluoro, cyano.
The acid phosphates of the formulae (I) and (Il) are, for the most part, well-known in the art, and can be prepared by methods well-known in the art. For example, the acid phosphates (I) and (Il) are obtained by reaction of the cc,. Iesponding alcohol or thiol R-XH, 5 v,~l .e. ei n R and X are as hereinbefore defined, with phospl1c . us pentoxide or phos~uhorus oxysulfide using the procedures described by Kosolapof, O. ydnopho~,~,horus Compounds, John WileyandSons, Inc (NewYork, 1950),pp.220-221. Thisreactiongivesrisetoamixtureofthe mono- and di-acid phosphates, which mixture can be separated, if desired, for example by fractional crystallization of the barium and like salts as described in the above cited ~ere.ence.
20 The individual acid phosphates in the mixture of the mono- and di-acid phosphates obtained in accordance with the above reaction can be employed as starting materials in the process of the invention.
It is possible to convert acid phosphates, having the formula (I) and (Il) above, to a product containing the corresponding py. ophos~hates and their sulfur-containing analogues, 25 such as thiophosphates and pyrophos~.holl .iolates, by heating the acid phosphates in the presence of an organic polyisocyanate, with or without any other reactant such as phosphorus oxychloride, phosgene and the like. If the conditions of heating are carefully controlled as described herein, the resulting product is a homogeneous liquid which can be stored for prolonged periods without any tendency to undergo phase separation.
The fact that there are any conditions at all which could lead to the formation of a phase-stable product was, prior to disclosure in, for example, U.S. 4,258,169, Re. 31,703 and JP
618469,surprisingtothoseskilledintheart. Ithadpreviouslybeenexpectedthatthereaction of an acid phosphate of the type shown in formulae (I) or (Il) with an organic isocyanate would proceed in accordance with the following equation in which R has the significance defined 35 above and R' represents the residue of the organic isocyanate, which latter is shown as monomeric for the sake of si mpl i city:
CA 022182~4 1997-10-14 W O96/33231 PCTnUS96/04120 O O O
2(RO)2-P-OH + R'NCO - (RO)2-P-o-p(oR)2 + C~2 + R NH2 (III) (IV) r~
5 The reaction would be eA~,e~Led to result i n the formation of the desired py, ophos~,hate in association with some polyphosphate (if a mono-ester is ~u, ejenL). The reaction also would be eA~Je~Ledtogiverisetothei.)Le,.,,ediateformationoftheamine(lV)cc,,,.::,,uondingtothe starting isocyanate. The amine (IV) would be expected to react immediately with addi Lional isocyanate to form a urea. If a polyisocyanate were used a polyurea would be eA~e-Led to 10 form, and such should normally be insoluble in the reaction product and separdLe as a solid either immediately or on ~Ldnding.
This is indeed what is found to happen when the acid-phospl1dLe (I) or (Il) is reacted with the organic polyisocyanate at any temperature below 60~C. However, if the reactioniscarriedoutabovethatte""~e,dLurebutbelow190~C,itwasfoundthatitispossible toobtainaproductwhich,oncoolingtoambientLe""~e,dLure(15-25~C)andmai"Laining thereat even for prolonged periods, does not deposit solid material.
However,thereactiontemperatureisnottheonlyi",poiLdnLfactor. Itisfound thatthetimeforwhichheatingiscarriedoutisi",po,LdnLand,ingeneral,thehigherthe reaction temperature, the shorter the period for which the heating can be carried out without 20 consequences which are fatal to the improvement of phase stability in the reaction product.
Il l ustratively, even when the reaction tem perature is as low as 60~C, it is found that there is a limited time beyond which further heating causes transformation of the pyrophosphates into what are believed to be higher polyphosphates. When the pr~"~o, Lion of the latter in the reaction product reaches a sufficiently high level it is found that on subsequent cooling of the 25 reaction product, the polyphosphates separate generally as a liquid layer immiscible with the polyisocyanate. Further, the higher the reaction temperature, the shorter the period for which the reaction of acid phosphate and polyisocyanate can be allowed to continue without the onsetoftheabovedescribed L~dn~ru~ ationofthepy~opl~osphates The exact chemical composition of the products which separate, either when 30 operating at a temperature less than the minimum set forth above or when heating for a period longer than that which will give rise to a homogeneous liquid product, is not known precisely and is not believed to be i mportant to an understanding of the i nvention The above discussion has been offered by way of explanation o~lly and it is to be understood that the scope and import of the invention is not to be limited in any manner whatsoever by reason of 35 the tentative identification of the by-products set forth above.
The time and the te".pe, dLure for which the process described hereinabove can be carried out can vary accordi ng to the particular acid phosphate and polyisocyanate, as well CA 022182~4 1997-10-14 W O96/33231 PCTnUS96/04120 astheconce..L,dLionoftheacidpho~,~,l.aLe,whichareemployed. Theappropriatetimeinany given instance can be determined readily by a process of trial and error. In general, the reaction times which can be employed vary from several hours at 60~C down to a minute or less atthehigherendoftheLe..-perdLurerange(190~C). Assetforthabove,thehigherthe temperature employed, the shorter the reaction time which can be employed without 5 deleterious results.
The manner in which the acid phosphate and the organic polyisocyanate are brought together can also, in certain cases, affect the ability to produce a phase-stable co~posilioninaccordancewiththeinvention. Itispossibleinmanyinstancestobringthetwo reactants together, in any conventional manner, at ambient L~:...pe. dLure, and then to heatthe 10 resulting mixture at a temperature within the range set forth for a time which has been determinedtogivethedesired resultatthe particularreactiontemperaturechosen. However, it is pr.: rl . . ed to preheat the polyisocyanate to the selected reaction temperature and then to add the acid phosphate to the preheated polyisocyanate. When operating a batch type procedure, the addition can be carried out in a single charge or can be carried out slowly over a 5 period of time.
The process of the invention can also be carried out in a continuous manner in which the mixture of polyisocyanate (prere.ably preheated) and acid phosphate is passed through a heating zone maintained at a temperature within the range set forth above. The rateofflowofmixturethroughtheheatingzoneisadjustedsothattheresidencetimeinthe 20 mixing zone co. . esponds to the selected reaction time. A wide variety of con~.~nLional equipment can be employed for this purpose A particularly useful apparatus is that of the type in which the mixture to be heated is spread in the form of a thin film over the walls of the heating vessel. Atypical example of such apparatus isthatsetforth in U.S. Pat. No. 2,927,634 In another embodiment the polyisocyanate (p(erel dbly preheated) and the acid phosphate are 25 charged continuously, in the appropriate proportions, to a stirred reactor in which the reactants are maintained at the desired temperature The reaction mixture is withdrawn from the reactor at the same rate as the fresh reactants are added and the rate of addition and withdrawalaresuchthattheresidencetimeofthemixtureinthereactorcorrespondstothe selected reaction time. During preparation of the mixture, carbon dioxide is continuously 30 evolved.
Whether the process of the invention is carried out in a batch or continuous manner, it is desirable that the reaction be carried out in the absence of oxygen and moisture, i.e, in the presence of an inert gas such as nitrogen in accordance with the usual practice of handling polyisocyanates Such may include, for example, a blanket or sparge Thus, the final 35 mixture is saturated with dissolved gases which include primarily carbon dioxide as evolved, and this is the case whether the reaction is carried out under a nitrogen blanket or under air.
However, if a nitrogen sparge is used, the mixture will contain primarily ni L,ogen, since the CA 022182~4 1997-10-14 W O 96/33231 PCTrUS96/04120 n;L,ugen forces outthe carbon dioxide being evolved bythe reaction between the polyisocyanate and the acid phosphate. Minor pfOpOI Lions of other gases may also be present in some embodiments.
The p- OpGI Lions in which the polyisocyanate and the acid phG,pha Les (I) and or (Il) are employed in the process of the invention can vary over a wide range but advanLageously v 5 theacid phosphateisemployed inanamountcoespondingfrom 1 to20partsbyweightper 100 parts by weight of polyisocyanate. In a p. er~-, ed embodiment the amount of acid phosphate employed is such that the polyisocyanate co, . ~pc ,i Lions produced in accordance withtheinventioncontainfromO.1,preferablyfrom3,to 15,preferablyto 10,mostp.~:rerably to 8, percent by weight of the acid phospha Le.
The polyisocyanate employed in the process of the i nvention can be any organic polyisocyanate which contains at least two isocyanate groups per molecule. Illustrative of organic polyisocyanates are diphenylmethane diisocyanate, m- and p-phenylene diisocyanates, chlorophenylene diisocyanate, a,a'-xylylene diisocyanate, 2,1 and 2,6-toluene diisocyanate and the mixtures of these latter two isomers which are available commercially, including 5 triphenylmethane triisocyanates, 4,4-diisocyanatodiphenyl ether, and polymethylene polyphenyl polyisocyanates. The latter polyisocyanates are mixtures containing from 25 to 90 percent by weight of methylenebis(phenyl isocyanate) the remainder of the mixture being polymethylene polyphenyl polyisocyanates of functionality higherthan 2Ø Such polyisocyanates and methods fortheir preparation are well-known in the art; see, for example, 20 U.S. Patent Nos. 2,683,730; 2,950,263; 3,12,008 and 3,097,191.
These latter polyisocyanates are also available in various modified forms One such form comprises a polymethylene polyphenyl polyisocyanate which has been subjected to heat treatment, generally at temperatures from 150~C to 300~C until the viscosity (at 25~C) has been increased to a value withi n the range of 800 to 1500 centipoise (cps) Another modified 25 polymethylene polyphenyl polyisocyanate is one which has been treated with minor amounts of an epoxide to reduce the acidity thereof in accordance with U.S. Patent No.3,793,362. The polymethylene polyphenyl polyisocyanates can also be employed i n the form of prepoly. "e, ~
and quasi-prepolymers, i.e., the products obtained by reacting the polyisocyanate with a minor amount of a polyol, as well as in the form of polyisocyanates which have been partially blocked 30 by reaction with a monohydric alcohol using procedures well-known in the art Carbodiimide-modified methane diphenyl diisocyanates can also be used The polymethylene polyphenyl polyisocyanates are the p. e r~ d polyisocyanates foruseintheprocessoftheinvention. Particularlyp~r~..edpolymethylenepolyphenyl polyisocyanates are those which contain from 35 to 65 percent by weight of 35 methylenebis(phenyl isocyanate). Also pn r~" ed are those polyisocyanates having viscosities of less than 500 centipoise (cps), more preferably less than 300 cps, and most preferably less than 200 cps.
CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 While any of the acid phc ".haLes of formulae (I) and (Il) can be employed in the process of the invention, those acid phosphates wherein R represents alkyl or alkenyl and X
represents O, and more particularly, those acid phosphates wherei n R r~p~ eser, L~ al kyl or alkenyl having from 8 to 18 carbon atoms and X (eprese"l~ O, exhibit ad-,dnLdges because of 'r readyavailabilityand lowcost. Particularlypr~r~"~:d areacid phosphatesselectedfromthe 5 group consisting of C8 to C18 alkyl esters of mono- and diester phosphates and mixtures thereof The above-described process, which is described in greater detail in U.S. Patent4,258,169 and Re. 31,703, incor~uGrdLed herein by reference in its entirety, results in liquid polyisocyanate compositions which are generally more storage-stable as to phase separation 10 than polyisocyanate/~.hosphate mixtures which have not been subjected to this treatment, but which are still less storage-stable as to carbon dioxide generation than mixtures prepared by the process of the present invention. It is toward this latter aspect of storage stability that the present invention is particularly directed.
The increased stability as to carbon dioxide gene, dLion is err~.Led particularly by 5 the second step of the present invention, which involves subjecting the mixture to a negative pressure sufficientto remove at least a portion of the dissolved gases Lhelerl~,,.l. In a p.ere. ~ed embodiment, the negative pressure is a vacuum sufficient to remove at least 10 percent of the dissolved gases, more preferably at least 95 percent, and most preferably at least 99 percent. In orderto accomplish these higher levelsof dissolved gas removal, it is p.~rt:,-ed thatthe 20 negative pressurization (evacuation) be to less than 50 mm Hg (2 inches Hg), and more preferablytolessthan10mmHg(0.4inchHg). Theeffectivetimeoftheevacuationvaries, depending on the negative pressure employed as well as the concer LrdLion of the acid phosphate in the polyisocyanate. I loJIcvcr, preferablythe negative pressurization is held for at least 15 minutes, and more p,t r~. dbly at least 30 minutes, and most preferably from 1 to 3 25 hours. Inap.er~r.adembodimentthismostpr~r~.,edperiodofevacuationisappliedwhile maintaining a pressure reading of lessthan 10 mm Hg (0.4 inch Hg).
Equipment useful for the negative pressurization includes vacuum pumps, jets, aspirators or other conventional equipment.
The liquid, storage-stable polyisocyanate compositions prepared in accordance 30 with the process of this invention are particularly useful as binder resins for use in the preparation of particle boards in accordance with methods well-known in the art, as described in the "Background" section references cited hereinabove The compositions useful in the process of this invention possess the advantage of preventing adherence of the particle board to metal surfaces such as caul plates and press plate platens used in the p. epard Lion of such a 35 board For th!s particular use, i.e., as bi nder resi ns for particl e board, it is desi rable, but not essential, that the polyisocyanate compositions of the i nvention have a viscosity i n the range of from 100 to 3000 centipoise (cps) to facilitate ease of handling in the equipment currently CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 employed in the manufacture of particie board. Viscosities in the above range can be attained readilywhen employing polymethylene polyphenyl polyisocyanates having an initial viscosity of the order of 25 cps to 1000 cps and subjecting these polyisocyanates to the process of the invention. This rep~ese~ an additional reason for employing such polyiso.yanates in a p,~r~" ed embodimentofthe invention.
Where the polyisocyanate cc .. po,i lions of the invention are to be employed as bi nder resi ns i n the p. epard lion of particle boards for example, the polyisocyanate co" IpCI~i lion can be applied to the particle board chips, prior to heating and pressing of the latter, in the form of an aqueous emulsion or dispersion. In order to facilitate the formation of these, it is desirable to emp~oy an emulsifying or dispersing agent. If desired, the agent can be 10 incor~,c (aled into the polyisocyanate compositions of the invention so as to enable the particle board manufacturer to prepare the required emulsion or dispersion without the need to employ additional agents. The agent can be any of those known in the art including anionic and nonionic emulsifying and dispersing agents. Among such agents are, for example, polyoxyethylene and polyoxypropylene alcohols and block copolymers of two or more of 5 ethylene oxide, ,~ro~,,rlcne oxide, butylene oxide, and styrene; alkoxylated alkylphenols such as nonylphenoxypoly-(ethyleneoxy)ethanols; alkoxylated aliphatic alcohols such as ethoxylated and propoxylated aliphatic alcohols containing from 4 to 18 carbon atoms; glycerides of saturated and unsaturated fatty acids such as stearic, oleic, and ricinoleic acids; polyoxyalkylene esters of fatty acids such as stearic, lauric, oleic and like acids; fatty acid amides such as the 20 dialkanolamides of fatty acids such as stearic, lauric, oleic and similar acids; and sulfonates, sulfates, carboxylates and sarcosinates, such as sodium dodecylbenzene sulfonate, calcium dodecylbenzene sulfonate, and sodium lauryl sulfate. A detailed account of such materials is found in Encyclopedia of Chemical Technology, Second Edition. Vol 19, Interscience Publishers (New York 1969), pp. 531-554. As is known to those skilled in the art, however, the long-tern 25 storage stability of the final composition may be compromised in some instances by the presence of certain salts.
Also optionally, a non-active hydrogen containing solvent or diluent can be employed . In a pr~ - - ed embod i ment of the present i nvention such non-active hydrogen containing materials include esterified polyols and monols.
The following examples describe the manner and process of making and using the invention and set forth the best mode contemplated by the inventors of carrying outthe invention. However, they are not i ntended to be, nor should they be construed to be, limiting i n any way of the scope of the i nvention.
CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 Example 1 A reaction was carried out using as the acid phosphate a mixture of mono- and di-lauryl acid pho:.~vl-dLe (TRYFAC* 5573, commercially availabie from Henkel Industries) and, as the polyisocyanate, a polymethylene polyphenyl polyisocyanate containing app, oxi, . ,ately 46.5 percent by weight of methylenebis(phenyl isocyanate) and having an isocyanate equivalent of 134.5 and a viscosity of 25~C of 173 cps (PAPI* 27, commercially available from The Dow Chemical Company). The polyisocyanate starting amount was 900 pounds, and was charged to astainlesssteel reactionvessel equippedwithanagitatorand ni~-ogensparge. Itwasheated to80~Cwithstirringand32.6poundsofTRYFAC*5573wereaddedovera5-10minuteinterval to control foaming resulting from carbon dioxide evolution. Upon completion of the TRYFAC*
10 addition, the reaction was stirred at 80~C for two hours. Foaming of the reaction mixture was observed to continue. At the end of the reaction the n i l, ogen flow was shut off, full vacuum wasapplied(O-SOmmHg,0-2inchesHg)whiletheL~""~erdlurewasmaintainedat80~C,and the product was then cooled to ambient temperature. The vacuum was then discontinued and the product was drummed off. It was stored in an oven at 43-49~C and pressurization recorded 5 as shown in Table 1. The NCO content of the fi nal product was 30.1 percent by weight.
Comparative Example A
A reaction was carried out to illustrate the difference in the rate of drum pressurization between the Example 1 sample and a sample prepared using a similar 20 preparation method butwithoutthe step of being subjected to a negative pressure ("Comparative Example A Sample") To prepare the Comparative Example A Sample, about 900 pounds of PAPI* 27 were heated with 3.5 percent by weight of TRYFAC* 5573 for two hours at 82~C under nitrogen. No vacuum was applied to the product. The productwas cooled to ambient25 temperature, then I oaded i nto a heavy gauge d ru m (50 pounds per square i nch (psi) rati ng) and subjected to routine shipping over a period of about 12 days. The drum was equipped with a pressure gauge. It was placed in an oven at 60~C for the pressurization study.
Pressurization was measured over a period of time and recorded in Table 1.
W O96/33231 PCTrUS96/04120 Comparative Example Day from startExample 1 Sample A Sample of study psi pressure psi pressure O O 0.0 2 -- 2.8 6 0 3.5 8 -- 4.3 -- 5.3 ~o 14 0 7.5 37 0 __ 97 4 __ --indicates no data taken.
5 The reaction would be eA~,e~Led to result i n the formation of the desired py, ophos~,hate in association with some polyphosphate (if a mono-ester is ~u, ejenL). The reaction also would be eA~Je~Ledtogiverisetothei.)Le,.,,ediateformationoftheamine(lV)cc,,,.::,,uondingtothe starting isocyanate. The amine (IV) would be expected to react immediately with addi Lional isocyanate to form a urea. If a polyisocyanate were used a polyurea would be eA~e-Led to 10 form, and such should normally be insoluble in the reaction product and separdLe as a solid either immediately or on ~Ldnding.
This is indeed what is found to happen when the acid-phospl1dLe (I) or (Il) is reacted with the organic polyisocyanate at any temperature below 60~C. However, if the reactioniscarriedoutabovethatte""~e,dLurebutbelow190~C,itwasfoundthatitispossible toobtainaproductwhich,oncoolingtoambientLe""~e,dLure(15-25~C)andmai"Laining thereat even for prolonged periods, does not deposit solid material.
However,thereactiontemperatureisnottheonlyi",poiLdnLfactor. Itisfound thatthetimeforwhichheatingiscarriedoutisi",po,LdnLand,ingeneral,thehigherthe reaction temperature, the shorter the period for which the heating can be carried out without 20 consequences which are fatal to the improvement of phase stability in the reaction product.
Il l ustratively, even when the reaction tem perature is as low as 60~C, it is found that there is a limited time beyond which further heating causes transformation of the pyrophosphates into what are believed to be higher polyphosphates. When the pr~"~o, Lion of the latter in the reaction product reaches a sufficiently high level it is found that on subsequent cooling of the 25 reaction product, the polyphosphates separate generally as a liquid layer immiscible with the polyisocyanate. Further, the higher the reaction temperature, the shorter the period for which the reaction of acid phosphate and polyisocyanate can be allowed to continue without the onsetoftheabovedescribed L~dn~ru~ ationofthepy~opl~osphates The exact chemical composition of the products which separate, either when 30 operating at a temperature less than the minimum set forth above or when heating for a period longer than that which will give rise to a homogeneous liquid product, is not known precisely and is not believed to be i mportant to an understanding of the i nvention The above discussion has been offered by way of explanation o~lly and it is to be understood that the scope and import of the invention is not to be limited in any manner whatsoever by reason of 35 the tentative identification of the by-products set forth above.
The time and the te".pe, dLure for which the process described hereinabove can be carried out can vary accordi ng to the particular acid phosphate and polyisocyanate, as well CA 022182~4 1997-10-14 W O96/33231 PCTnUS96/04120 astheconce..L,dLionoftheacidpho~,~,l.aLe,whichareemployed. Theappropriatetimeinany given instance can be determined readily by a process of trial and error. In general, the reaction times which can be employed vary from several hours at 60~C down to a minute or less atthehigherendoftheLe..-perdLurerange(190~C). Assetforthabove,thehigherthe temperature employed, the shorter the reaction time which can be employed without 5 deleterious results.
The manner in which the acid phosphate and the organic polyisocyanate are brought together can also, in certain cases, affect the ability to produce a phase-stable co~posilioninaccordancewiththeinvention. Itispossibleinmanyinstancestobringthetwo reactants together, in any conventional manner, at ambient L~:...pe. dLure, and then to heatthe 10 resulting mixture at a temperature within the range set forth for a time which has been determinedtogivethedesired resultatthe particularreactiontemperaturechosen. However, it is pr.: rl . . ed to preheat the polyisocyanate to the selected reaction temperature and then to add the acid phosphate to the preheated polyisocyanate. When operating a batch type procedure, the addition can be carried out in a single charge or can be carried out slowly over a 5 period of time.
The process of the invention can also be carried out in a continuous manner in which the mixture of polyisocyanate (prere.ably preheated) and acid phosphate is passed through a heating zone maintained at a temperature within the range set forth above. The rateofflowofmixturethroughtheheatingzoneisadjustedsothattheresidencetimeinthe 20 mixing zone co. . esponds to the selected reaction time. A wide variety of con~.~nLional equipment can be employed for this purpose A particularly useful apparatus is that of the type in which the mixture to be heated is spread in the form of a thin film over the walls of the heating vessel. Atypical example of such apparatus isthatsetforth in U.S. Pat. No. 2,927,634 In another embodiment the polyisocyanate (p(erel dbly preheated) and the acid phosphate are 25 charged continuously, in the appropriate proportions, to a stirred reactor in which the reactants are maintained at the desired temperature The reaction mixture is withdrawn from the reactor at the same rate as the fresh reactants are added and the rate of addition and withdrawalaresuchthattheresidencetimeofthemixtureinthereactorcorrespondstothe selected reaction time. During preparation of the mixture, carbon dioxide is continuously 30 evolved.
Whether the process of the invention is carried out in a batch or continuous manner, it is desirable that the reaction be carried out in the absence of oxygen and moisture, i.e, in the presence of an inert gas such as nitrogen in accordance with the usual practice of handling polyisocyanates Such may include, for example, a blanket or sparge Thus, the final 35 mixture is saturated with dissolved gases which include primarily carbon dioxide as evolved, and this is the case whether the reaction is carried out under a nitrogen blanket or under air.
However, if a nitrogen sparge is used, the mixture will contain primarily ni L,ogen, since the CA 022182~4 1997-10-14 W O 96/33231 PCTrUS96/04120 n;L,ugen forces outthe carbon dioxide being evolved bythe reaction between the polyisocyanate and the acid phosphate. Minor pfOpOI Lions of other gases may also be present in some embodiments.
The p- OpGI Lions in which the polyisocyanate and the acid phG,pha Les (I) and or (Il) are employed in the process of the invention can vary over a wide range but advanLageously v 5 theacid phosphateisemployed inanamountcoespondingfrom 1 to20partsbyweightper 100 parts by weight of polyisocyanate. In a p. er~-, ed embodiment the amount of acid phosphate employed is such that the polyisocyanate co, . ~pc ,i Lions produced in accordance withtheinventioncontainfromO.1,preferablyfrom3,to 15,preferablyto 10,mostp.~:rerably to 8, percent by weight of the acid phospha Le.
The polyisocyanate employed in the process of the i nvention can be any organic polyisocyanate which contains at least two isocyanate groups per molecule. Illustrative of organic polyisocyanates are diphenylmethane diisocyanate, m- and p-phenylene diisocyanates, chlorophenylene diisocyanate, a,a'-xylylene diisocyanate, 2,1 and 2,6-toluene diisocyanate and the mixtures of these latter two isomers which are available commercially, including 5 triphenylmethane triisocyanates, 4,4-diisocyanatodiphenyl ether, and polymethylene polyphenyl polyisocyanates. The latter polyisocyanates are mixtures containing from 25 to 90 percent by weight of methylenebis(phenyl isocyanate) the remainder of the mixture being polymethylene polyphenyl polyisocyanates of functionality higherthan 2Ø Such polyisocyanates and methods fortheir preparation are well-known in the art; see, for example, 20 U.S. Patent Nos. 2,683,730; 2,950,263; 3,12,008 and 3,097,191.
These latter polyisocyanates are also available in various modified forms One such form comprises a polymethylene polyphenyl polyisocyanate which has been subjected to heat treatment, generally at temperatures from 150~C to 300~C until the viscosity (at 25~C) has been increased to a value withi n the range of 800 to 1500 centipoise (cps) Another modified 25 polymethylene polyphenyl polyisocyanate is one which has been treated with minor amounts of an epoxide to reduce the acidity thereof in accordance with U.S. Patent No.3,793,362. The polymethylene polyphenyl polyisocyanates can also be employed i n the form of prepoly. "e, ~
and quasi-prepolymers, i.e., the products obtained by reacting the polyisocyanate with a minor amount of a polyol, as well as in the form of polyisocyanates which have been partially blocked 30 by reaction with a monohydric alcohol using procedures well-known in the art Carbodiimide-modified methane diphenyl diisocyanates can also be used The polymethylene polyphenyl polyisocyanates are the p. e r~ d polyisocyanates foruseintheprocessoftheinvention. Particularlyp~r~..edpolymethylenepolyphenyl polyisocyanates are those which contain from 35 to 65 percent by weight of 35 methylenebis(phenyl isocyanate). Also pn r~" ed are those polyisocyanates having viscosities of less than 500 centipoise (cps), more preferably less than 300 cps, and most preferably less than 200 cps.
CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 While any of the acid phc ".haLes of formulae (I) and (Il) can be employed in the process of the invention, those acid phosphates wherein R represents alkyl or alkenyl and X
represents O, and more particularly, those acid phosphates wherei n R r~p~ eser, L~ al kyl or alkenyl having from 8 to 18 carbon atoms and X (eprese"l~ O, exhibit ad-,dnLdges because of 'r readyavailabilityand lowcost. Particularlypr~r~"~:d areacid phosphatesselectedfromthe 5 group consisting of C8 to C18 alkyl esters of mono- and diester phosphates and mixtures thereof The above-described process, which is described in greater detail in U.S. Patent4,258,169 and Re. 31,703, incor~uGrdLed herein by reference in its entirety, results in liquid polyisocyanate compositions which are generally more storage-stable as to phase separation 10 than polyisocyanate/~.hosphate mixtures which have not been subjected to this treatment, but which are still less storage-stable as to carbon dioxide generation than mixtures prepared by the process of the present invention. It is toward this latter aspect of storage stability that the present invention is particularly directed.
The increased stability as to carbon dioxide gene, dLion is err~.Led particularly by 5 the second step of the present invention, which involves subjecting the mixture to a negative pressure sufficientto remove at least a portion of the dissolved gases Lhelerl~,,.l. In a p.ere. ~ed embodiment, the negative pressure is a vacuum sufficient to remove at least 10 percent of the dissolved gases, more preferably at least 95 percent, and most preferably at least 99 percent. In orderto accomplish these higher levelsof dissolved gas removal, it is p.~rt:,-ed thatthe 20 negative pressurization (evacuation) be to less than 50 mm Hg (2 inches Hg), and more preferablytolessthan10mmHg(0.4inchHg). Theeffectivetimeoftheevacuationvaries, depending on the negative pressure employed as well as the concer LrdLion of the acid phosphate in the polyisocyanate. I loJIcvcr, preferablythe negative pressurization is held for at least 15 minutes, and more p,t r~. dbly at least 30 minutes, and most preferably from 1 to 3 25 hours. Inap.er~r.adembodimentthismostpr~r~.,edperiodofevacuationisappliedwhile maintaining a pressure reading of lessthan 10 mm Hg (0.4 inch Hg).
Equipment useful for the negative pressurization includes vacuum pumps, jets, aspirators or other conventional equipment.
The liquid, storage-stable polyisocyanate compositions prepared in accordance 30 with the process of this invention are particularly useful as binder resins for use in the preparation of particle boards in accordance with methods well-known in the art, as described in the "Background" section references cited hereinabove The compositions useful in the process of this invention possess the advantage of preventing adherence of the particle board to metal surfaces such as caul plates and press plate platens used in the p. epard Lion of such a 35 board For th!s particular use, i.e., as bi nder resi ns for particl e board, it is desi rable, but not essential, that the polyisocyanate compositions of the i nvention have a viscosity i n the range of from 100 to 3000 centipoise (cps) to facilitate ease of handling in the equipment currently CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 employed in the manufacture of particie board. Viscosities in the above range can be attained readilywhen employing polymethylene polyphenyl polyisocyanates having an initial viscosity of the order of 25 cps to 1000 cps and subjecting these polyisocyanates to the process of the invention. This rep~ese~ an additional reason for employing such polyiso.yanates in a p,~r~" ed embodimentofthe invention.
Where the polyisocyanate cc .. po,i lions of the invention are to be employed as bi nder resi ns i n the p. epard lion of particle boards for example, the polyisocyanate co" IpCI~i lion can be applied to the particle board chips, prior to heating and pressing of the latter, in the form of an aqueous emulsion or dispersion. In order to facilitate the formation of these, it is desirable to emp~oy an emulsifying or dispersing agent. If desired, the agent can be 10 incor~,c (aled into the polyisocyanate compositions of the invention so as to enable the particle board manufacturer to prepare the required emulsion or dispersion without the need to employ additional agents. The agent can be any of those known in the art including anionic and nonionic emulsifying and dispersing agents. Among such agents are, for example, polyoxyethylene and polyoxypropylene alcohols and block copolymers of two or more of 5 ethylene oxide, ,~ro~,,rlcne oxide, butylene oxide, and styrene; alkoxylated alkylphenols such as nonylphenoxypoly-(ethyleneoxy)ethanols; alkoxylated aliphatic alcohols such as ethoxylated and propoxylated aliphatic alcohols containing from 4 to 18 carbon atoms; glycerides of saturated and unsaturated fatty acids such as stearic, oleic, and ricinoleic acids; polyoxyalkylene esters of fatty acids such as stearic, lauric, oleic and like acids; fatty acid amides such as the 20 dialkanolamides of fatty acids such as stearic, lauric, oleic and similar acids; and sulfonates, sulfates, carboxylates and sarcosinates, such as sodium dodecylbenzene sulfonate, calcium dodecylbenzene sulfonate, and sodium lauryl sulfate. A detailed account of such materials is found in Encyclopedia of Chemical Technology, Second Edition. Vol 19, Interscience Publishers (New York 1969), pp. 531-554. As is known to those skilled in the art, however, the long-tern 25 storage stability of the final composition may be compromised in some instances by the presence of certain salts.
Also optionally, a non-active hydrogen containing solvent or diluent can be employed . In a pr~ - - ed embod i ment of the present i nvention such non-active hydrogen containing materials include esterified polyols and monols.
The following examples describe the manner and process of making and using the invention and set forth the best mode contemplated by the inventors of carrying outthe invention. However, they are not i ntended to be, nor should they be construed to be, limiting i n any way of the scope of the i nvention.
CA 022182~4 1997-10-14 W O96/33231 PCTrUS96/04120 Example 1 A reaction was carried out using as the acid phosphate a mixture of mono- and di-lauryl acid pho:.~vl-dLe (TRYFAC* 5573, commercially availabie from Henkel Industries) and, as the polyisocyanate, a polymethylene polyphenyl polyisocyanate containing app, oxi, . ,ately 46.5 percent by weight of methylenebis(phenyl isocyanate) and having an isocyanate equivalent of 134.5 and a viscosity of 25~C of 173 cps (PAPI* 27, commercially available from The Dow Chemical Company). The polyisocyanate starting amount was 900 pounds, and was charged to astainlesssteel reactionvessel equippedwithanagitatorand ni~-ogensparge. Itwasheated to80~Cwithstirringand32.6poundsofTRYFAC*5573wereaddedovera5-10minuteinterval to control foaming resulting from carbon dioxide evolution. Upon completion of the TRYFAC*
10 addition, the reaction was stirred at 80~C for two hours. Foaming of the reaction mixture was observed to continue. At the end of the reaction the n i l, ogen flow was shut off, full vacuum wasapplied(O-SOmmHg,0-2inchesHg)whiletheL~""~erdlurewasmaintainedat80~C,and the product was then cooled to ambient temperature. The vacuum was then discontinued and the product was drummed off. It was stored in an oven at 43-49~C and pressurization recorded 5 as shown in Table 1. The NCO content of the fi nal product was 30.1 percent by weight.
Comparative Example A
A reaction was carried out to illustrate the difference in the rate of drum pressurization between the Example 1 sample and a sample prepared using a similar 20 preparation method butwithoutthe step of being subjected to a negative pressure ("Comparative Example A Sample") To prepare the Comparative Example A Sample, about 900 pounds of PAPI* 27 were heated with 3.5 percent by weight of TRYFAC* 5573 for two hours at 82~C under nitrogen. No vacuum was applied to the product. The productwas cooled to ambient25 temperature, then I oaded i nto a heavy gauge d ru m (50 pounds per square i nch (psi) rati ng) and subjected to routine shipping over a period of about 12 days. The drum was equipped with a pressure gauge. It was placed in an oven at 60~C for the pressurization study.
Pressurization was measured over a period of time and recorded in Table 1.
W O96/33231 PCTrUS96/04120 Comparative Example Day from startExample 1 Sample A Sample of study psi pressure psi pressure O O 0.0 2 -- 2.8 6 0 3.5 8 -- 4.3 -- 5.3 ~o 14 0 7.5 37 0 __ 97 4 __ --indicates no data taken.
Claims (10)
1. A process for preparing a liquid, storage-stable polyisocyanate composition comprising the steps of (1) heating a mixture of a polyisocyanate and an acid phosphate at a temperature in the range of from 60°C to 190°C for a time such that no phase separation occurs upon cooling the reaction mixture to ambient temperature, wherein the mixture contains dissolved gases; and (2) subjecting the mixture to a negative pressure sufficient to remove at least a portion of the dissolved gases therefrom.
2. The process of Claim 1 wherein the negative pressure measures less than 50 mm Hg.
3. The process of Claim 2 wherein at least 90 percent of the dissolved gases is removed.
4. The process of Claim 1 wherein the negative pressure measures less than 10 mm Hg.
5. The process of Claim 4 wherein at least 99 percent of the dissolved gases is removed.
6. The process of Claim 1 wherein the organic polyisocyanate is polymethylene polyphenyl polyisocyanate, and the acid phosphate is selected from the group consisting of C8 to C18 alkyl esters of mono- and diester phosphates and mixtures thereof.
7. The process of Claim 6 wherein the acid phosphate is selected from the group consisting of lauryl acid phosphate, tridecyl phosphate, decyl phosphate and mixtures thereof.
8. The process of Claim 6 wherein the acid phosphate is present in an amount from 3 to 10 percent by weight.
9. The process of Claim 1 wherein the polyisocyanate is a polyphenyl polymethylene polyisocyanate having a viscosity of less than 500 centipoise.
10. In a process for preparing a liquid, storage-stable polyisocyanate composition containing a release agent formed in situ, which includes heating at a temperature in the range of 60°C to 190°C a mixture of an organic polyisocyanate and from 1 to 20 parts, per 100 parts by weight of said polyisocyanate, of a compound of one of the following formulas:
and (I) (II) and mixtures of two or more of the acid phosphates, wherein each R is independently selected from the group consisting of alkyl having at least 3 carbon atoms, alkenyl having at least 3 carbon atoms, aryl, aryl substituted by at least one alkyl group, alkyl substituted by at least one acyloxy group, wherein the acyl group is the residue of an aliphatic monocarboxylic acid having at least 2 carbon atoms, and wherein R1 is selected from the group consisting of alkyl, aryl, and aryl substituted by at least one alkyl, one of A and B represents hydrogen and the other is selected from the group consisting of hydrogen, methyl, chloromethyl and 2,2,2-trichloroethyl; X is chalcogen selected from the group consisting of oxygen and sulfur; and m is a number having an average value of 1 to 25; the heating being carried out for a time such that no phase separation occurs upon cooling the reaction mixture to ambient temperature; the mixture containing dissolved gases;
an improvement comprising a further step of subjecting the reaction mixture to a negative pressure for a time sufficient to remove at least a portion of the dissolved gases therefrom.
and (I) (II) and mixtures of two or more of the acid phosphates, wherein each R is independently selected from the group consisting of alkyl having at least 3 carbon atoms, alkenyl having at least 3 carbon atoms, aryl, aryl substituted by at least one alkyl group, alkyl substituted by at least one acyloxy group, wherein the acyl group is the residue of an aliphatic monocarboxylic acid having at least 2 carbon atoms, and wherein R1 is selected from the group consisting of alkyl, aryl, and aryl substituted by at least one alkyl, one of A and B represents hydrogen and the other is selected from the group consisting of hydrogen, methyl, chloromethyl and 2,2,2-trichloroethyl; X is chalcogen selected from the group consisting of oxygen and sulfur; and m is a number having an average value of 1 to 25; the heating being carried out for a time such that no phase separation occurs upon cooling the reaction mixture to ambient temperature; the mixture containing dissolved gases;
an improvement comprising a further step of subjecting the reaction mixture to a negative pressure for a time sufficient to remove at least a portion of the dissolved gases therefrom.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US42306095A | 1995-04-17 | 1995-04-17 | |
| US08/423,060 | 1995-04-17 |
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| Publication Number | Publication Date |
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| CA2218254A1 true CA2218254A1 (en) | 1996-10-24 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002218254A Abandoned CA2218254A1 (en) | 1995-04-17 | 1996-03-26 | Process for preparing a storage-stable mixture of polyisocyanate and phosphate |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0821706A1 (en) |
| JP (1) | JPH11503786A (en) |
| KR (1) | KR19990007809A (en) |
| CN (1) | CN1181765A (en) |
| AU (1) | AU5431996A (en) |
| BR (1) | BR9608163A (en) |
| CA (1) | CA2218254A1 (en) |
| CO (1) | CO4410409A1 (en) |
| MX (1) | MX9707969A (en) |
| NO (1) | NO974785D0 (en) |
| WO (1) | WO1996033231A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10046612A1 (en) * | 2000-09-20 | 2002-03-28 | Basf Ag | Reproducible production of purification agent comprises dissolving phosphoric acid and isocyanate and/or polyisocyanate in solvent |
| DE102006052987A1 (en) * | 2006-11-10 | 2008-05-15 | Bayer Materialscience Ag | Plastic composite elements and a method for their production |
| US20130245222A1 (en) * | 2012-03-15 | 2013-09-19 | Basf Se | Modified isocyanate compositions and mehtods of preparing the same |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE864326A (en) * | 1977-03-01 | 1978-08-28 | Asahi Chemical Ind | PROCESS FOR PREPARING AN ORGANIC POLYISOCYANATE |
| US4257995A (en) * | 1979-05-03 | 1981-03-24 | The Upjohn Company | Process for preparing particle board and polyisocyanate-phosphorus compound release agent composition therefor |
| US4258169A (en) * | 1980-03-26 | 1981-03-24 | The Upjohn Company | Polyisocyanate compositions containing in-situ formed pyrophosphate mold release agent and process of making |
| US4382108A (en) * | 1981-12-21 | 1983-05-03 | The Upjohn Company | Novel compositions and process |
-
1995
- 1995-06-23 CO CO95027884A patent/CO4410409A1/en unknown
-
1996
- 1996-03-26 CA CA002218254A patent/CA2218254A1/en not_active Abandoned
- 1996-03-26 JP JP8531745A patent/JPH11503786A/en active Pending
- 1996-03-26 MX MX9707969A patent/MX9707969A/en unknown
- 1996-03-26 CN CN96193363A patent/CN1181765A/en active Pending
- 1996-03-26 AU AU54319/96A patent/AU5431996A/en not_active Abandoned
- 1996-03-26 WO PCT/US1996/004120 patent/WO1996033231A1/en not_active Application Discontinuation
- 1996-03-26 EP EP96911430A patent/EP0821706A1/en not_active Withdrawn
- 1996-03-26 BR BR9608163A patent/BR9608163A/en not_active Application Discontinuation
- 1996-03-26 KR KR1019970707332A patent/KR19990007809A/en not_active Application Discontinuation
-
1997
- 1997-10-16 NO NO974785A patent/NO974785D0/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| WO1996033231A1 (en) | 1996-10-24 |
| NO974785L (en) | 1997-10-16 |
| BR9608163A (en) | 1999-02-09 |
| NO974785D0 (en) | 1997-10-16 |
| KR19990007809A (en) | 1999-01-25 |
| AU5431996A (en) | 1996-11-07 |
| EP0821706A1 (en) | 1998-02-04 |
| CO4410409A1 (en) | 1997-01-09 |
| JPH11503786A (en) | 1999-03-30 |
| MX9707969A (en) | 1997-12-31 |
| CN1181765A (en) | 1998-05-13 |
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| Date | Code | Title | Description |
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| FZDE | Dead |