CA1174787A - Cured polyurethanes - Google Patents
Cured polyurethanesInfo
- Publication number
- CA1174787A CA1174787A CA000343069A CA343069A CA1174787A CA 1174787 A CA1174787 A CA 1174787A CA 000343069 A CA000343069 A CA 000343069A CA 343069 A CA343069 A CA 343069A CA 1174787 A CA1174787 A CA 1174787A
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- Canada
- Prior art keywords
- polyols
- diisocyanate
- polyurethane
- hydroxyl
- groups
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- 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
- C08G18/08—Processes
- C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
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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)
Abstract
Abstract The invention relates to polyurethanes prepared by reacting at least one selected aromatic diamine with an inocyanate-terminated prepolymer The particular diamines are selected from 3,5-diaminobenzotrifluoride and bis-(2-aminophenyl)sulfide.
Description
~7~7i5'7 'Cured'Pblvure't~an~s Technical Field This invention relates to cured polyurethanes prepared by curing polyurethane precursors with selected aromatic diamines.
Background Art Diamines are especially valuable for curing various polyurethanes, particularly isocyanate terminated poly-urethane prepolymers. Aromatic diamine curatives are particularly valuable for curing aromatic isocyanate-terminated prepolymers (,to provide polyurethanes having enhanced age resistance in the presence of moisture and various liquid hydrocarbon fuels). However, many aromatic diamines typically react too fast with aromatic isocyanate-terminated prepolymers and therefore seriously inhibit their commercial significance. The 4,4'-methylene bis (2-chloroaniline), sometimes reerred to as MOCA, a well known diamine, is slower reacting at ' room temperature and should be considered one of the exceptions to such typical fast reacting aromatic diamines.
For such MOCA cured aromatic NCO-terminated prepolymers a catalyst is many times used to shorten the reaction time and enhance their commercial signifi-cance especially in the preparation of ure~hane films in solution systems.
Therefore, it is an,object of this invention to provide aromatic diamines suitable for curing aromatic isocyanate-terminated polyurethane prepolymers, methods of preparing such aromatic diamines and isocyanate-términated polyurethanes extended with aromatic diamines.
Disclosure And Practice Of Invention In'accordance with this invention? a cured poly-urethane is provided which is prepared by reacting (A) a diamine selected from at least one of the group , 7~
.2 consisting o~ 3,5-diam~nobenzotrifluoride, and ~is(:2-aminoph.enyl)sulf~de, with.'(B.~ an isocyanate~ter~inated prepolymèr prepared ~y the meth.od which co~prises reacting a poly~socyanate h.a~ing an i.socyanato function-ality o~ 2 to 3, wit~.a ~olyol com~rised o~ about 80 toabout lO.0 wei.~ht percent polymeric pol~ols selected from ~olyester polyols, polyether ~olyols and hydroxyl terminated unsaturated polymerlc polyols, and, correspond-ingly, about 20 to a~out 0 weight percent monomeric hydrocarbon d~ols hav~ng 3 to 8 carbon atoms; where the ratio of ~socyanato graups to hydroxyl ~roups of the polyol, or polyol mixture, is in the range of about 1~3!1 to about 5/1, and where the ratio of amino groups of said diamine to excess isocyanato groups of said hydroxyl groups is in the range of about 0.5/1 to a~out 1. 1~1. ' Rep~e.sentative examples of various monomeric polyols suitable for use in the preparation of the polyurethane are ethylene glycol, 1,3-propane diol, 1,4-butane diol, 1,5-pentane diol, 1,6-hexane diol and decamethylene glycol.
The polyurethane reaction mixtures used in this invention are typically liquid mixtures with the addition of a solvent commonly used to prepare poly-urethanes, if desired, and particularly flexible polyurethanes, by the well known one-shot prepolym~r or quasi-prepolymer techniques. The quasi-prepolymer method differ's from the prepolymer method in that only a portion of the pol~ol is initially reacted with the 3G polyisocyanate, with the remainde.r then added and reacted to form the prepQlymer. The prepolymer i5 then cured ox extended ~ith t~e d'i.a~ine.
The cura.t.i~e., pol~ols and polyisocyanates are typically reacted ~t te~pe.~atu~es in the range o about 20C, to about 15~C. and pre.f~er~ in t~.e range o~
about 2~C. to about lO~QG.
A sol~ent can ~e u~.-ed ~ith th.e'reaction mixture to facilitate its use ~n the form of a fluid mixture or 7~'7 solution, although it is generally preferred to use the reaction mixture with only a minor amount of solvent, if any. If a solvent is used, it can be added to form a mixture containing up to about 60 weight percent solvent based on the total mixture. A preferable mixture can contain from about 40 to about 95 weight percent solids. However, a higher or lower concentra-tion of solids might be used. When the solids concen-tration is low, the individual applications will tend to deposit a thin layer of polyurethane polymer and a large amount of the solvent will have to be removed during the curing process. A solids concentration of 45 weight percent or higher is generally desired if a solven~ is used.
Other methods generally known for the preparatiGn of polyurethane reaction mixtures with or withou~ the aid of solvents may also be used.
The diamine curative of this invention has a curative reactivity which allows improved processing for many commercial applications. Indeed, its typical curative reactivity with aromatic isocyanate-terminated polyurethane prepolymers enhances such a polyuréthane's commercial significance. The curative reactivity is valuable because it typically provides a shorter reaction time instead of the rather slow reaction provided by sterically hindered diamines like 4,4'-methylene-bis-(2-chloroaniline~, otherwise known as MOCA.
Thus, the diamine curatives of this invention can, if desired, eliminate the need o a catalyst such as the well-known tertiary amines, the tin salts of fatty acids, such as dibutyltin dilaurate and stannous octoate and accelerators such as ~ercaptobenzothiazole.
Xn the preparation o~ the polyurethanes by this invention, the polymeric polyols typically comprise at least one member selected from the group consisting of polyester polyols, polyether polyols, and hydroxyl-terminated unsaturated polymeric polyols. The hydroxyl-terminated unsaturated polymeric polyols typically have a molecular weight of from about 2000 to about ~000 and ~L7~8t~
a hydroxyl functionality o from about 2 to about 3.
The reactive hydrogen-containing material generally used, other than the hydroxyl-terminated unsaturated polymeric polyol, has a molecular weight in the range of from about 500 to about 5000, and usually from about 1000 to about 3000. (I the molecular weight of the reactive hydrogen-containing material is too low, the polyurethane will not have suicient elasticity.) Generally, the polyester polyols are the preferred 10 active hydrogen-containing material where high strength and solvent resistance are desired.
Representative examples of polyester polyols are the condensation products of low molecular weight polyols wlth an organic polycarboxylic acid or anhydride.
15 ~epresentative low molecular weight polyols are glycols such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, decamethylene glycol, etc.
Representative examples o the organic dicarboxylic acids that can be used are succinic acid, glutaric 20 acid, adipic acid, phthalic acid, terephthalic acid, isophthalic acid, suberic acid, sebacic acid, pimelic acid and azelaic acid. The anhydrides of such acids can be used in place of the acid. If desired, rom about 1 to 20 percent by weight of a triol or higher 25 polyfunctional polyol or polyfunctional acid can be present to produce branching in the polyurethane polymer.
Further examples o polyesters are caprolactone polyesters. The caprolactone polyesters are substan-tially linear, hydroxyl-terminated polymers prepared by 30- reactin~ a caprolactone having 6 to 8 carbon atoms, preferably 6 carbon atoms, with a glycol having 4 to 7 carbon atoms and preferably 4 to 6 carbon atoms.
Various suitable caprolactones include ~ -caprolactone, zeta-caprolactone and eta-capro-t 35 lactone. Alkyl substituted caprolactones can be used with alk~l substituents containing 1 to 2 carbon atoms selected from methyl and ethyl radicals such as methyl ~ -caprolactone. Desirably, the caprolàctone polyester has a molecular weight in the range of about 800 to about 3500, preferably about 1200 to about 3000, with - corresponding hydroxyl numbers in the range of about 140 to about 32 and about 95 to about 37, respectively.
Polyether polyols useful in preparing the poly-urethanes of this invention can be prepared by poly-merizing or copolymerizing alkylen~ oxides, such as ethylene oxide, propylene oxide, and butylene oxides, by polymerizing or copolymerizing the low molecular weight glycols, or by the reaction of one or more such alkylene oxides with the glycols or with triol, or with a polycarboxylic acid, such as phthalic acid. The polyether polyols include polyalkylenearyl ether glycols or triols, polytetramethylene ether glycols, polyalkylene ether-thioether glycols or triols and alkyd resins.
Generally the polytetramethylene ether glycols are the preferred polyether glycols.
It is usually preferred that the hydroxyl-terminated unsaturated polymeric polyol has a molecular weight of 20 from about 2000 to about 4000 and a corresponding hydroxyl number of from about 50 to about 25. The hydroxyl-terminated unsaturated polymeric polyols used in this invention are unsaturated polymers of the type prepared by polymerizing unsaturated monomers comprising 25 from about 70 to about 100 percent conjugated dienes selected from the group consist-ing o 1,3-butadiene and isoprene and up to abut 30 percent styrene with the aid of organic peroxy catalysts to provide polymers which are gen~rally terminated at both ends of their chain 3~ with hydroxyl groups and have a hydroxyl functionality of from about 2 to about 3 and usually from about 2.1 to about 2,8. The preferred hydroxyl-containing poly-meric polyols are polybutadiene polyols, polyisoprene polyols~ butadiene-sty~ene copolymer polyols having about 70 to 90 percent units derived from butadiene and about 30 to 10 percent units derived from styrene and also butadienè-acrylonitrile copolymer polyols.
The organic polyisocyanates used in this invention having 2 to 3 isocyanato groups particularly include various organic diisocyanates, dimers and trimers thereof, and their mixtures as well as polyisocyanates having 2.3 to 2.7 isocyanato groups. The organic polyisocyanates can be aromatic, aliphatic or cyclo-aliphatic or combinations of these types.
Representative examples of such polyisocyanatesinclude the toluene diisocyanates, m-phenylene diiso-cyanate, 4-chloro-1,3-phenylene diisocyanate, 4,4'-tetramethylene diisocyanate, 1,6-hexamethylene diiso-10 ' cyanate, 1,10-decamethylene diisocyanate, 1,4-cyclo-hexylene diisocyanate, 4,4'-methylene-bis (cyclo-hexylisocyanate), 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate and 1,5-tetrahydronaphthalene diisocyanate and mixtures of such diisocyanates For ~he purposes of the present invention, the toluene diisocyanates,' diphenylmethane-4,4'-diisocyanate, 3,3'-dimethyI-4,4'-bis-phenylene diisocyanate, 4,4'-methylene-bis(cyclo-hexylisocyanate~ and 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate are preferred. For convenience, these diisocyanates are sometimes referred to as TDI, ~DI, TODI, H12 MDI and DMMDI, respectively.
~ aricus non-reactive solvents known to those skilled in the polyurethane art can be used for the preparation of the prepolymer solùtions and polyurethane reaction mixtures, if a solvent is desi~ed. ~epresenta-tive ex~mples of the solvents are aromatic solvents such as benzene, xylene and toluene and ~he liquid lower ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone. If the polyurethane reaction ~ixtuxes are to be used to prepare the cured polyurethanes in confined areas which are subject to explosive hazardsj nonflammable polyurethane solvents can be used to form nonflammable polyurethane reaction mixtures. Mixtures of solvents may also be used to obt~in sat~sfactory spreading properties and evaporation rates when the polyuret~ane spray composition is applied to a polymeric surface.
To enhance the cured polyurethane's hydrolysis resistance, about 1 to about 15, preferably about 2 to ~74~
about 5, weight percent of an epoxy resin and at least suEficient to give an excess of epoxide groups relative to the total excess of amino groups of the diamine curative over the said isocyanato groups might be used.
Thus, for such a modification an excess of epoxide groups is required over the amino groups of the curative, such as at least about 5 to about 50 equivalent percent excess, based on two epoxy groups per amino (-NH2) group, to provide a polyurethane composition containing sufficient free epoxide groups.
Hydrolysis resistance is typically determined by immersion in distilled wa~er at 158F. A substantial retention of tensile strength and elongation after 1~
days immersion can be related to a substantial resistance to hydroly5is. The tensile and elongation are normally determined at about 25C. by methods typically used by those skilled in the art.
Preferred resins for this invention are derived from epichlorohydrin and 2,2'-bis(4-hydroxyphenyl) propane with an epoxide equivalency of about 150 -to about 220, preferably about 175 to about 210. Resins which are pourable liquids at about 25C. are preferred but others can be used in solution. Typical resins are those obtainable under the tradenames Epon 828 and Epon 1001 from the Shell Chemical Company.
. The practice of this inven~ion is further illus-trated by reference to the following examples which are intended to be representatîve rather than restrictive of the scope of the invention. Unless otherwise indi-c~ted, all parts and percentages a~e by weight.
- EXoMP*E I
Cured polyurethanes were prepared by reacting various diamines of this invention with various iso-cyanate-terminated polyurethane prepolymers.
The prepolymers were p~epared by reacting an excess of various diisocyanates with various polymeric polyether and polyester polyols. The diisocyanates were selected from 4,4'-diphenyl methane diisocyanate .' - (MDI) and 3,3'-dimethyl-4,4'-diisocyanato diphenyl 1~478 ~
methane (DMMDI). The various polymeric polyols were selected from polyethylene adipate with a molecular weight (mw) of about 1000, polypropylene adipate (mw 2000), and polytetramethylene ether glycol (mw 2000).
5The experiments and physical properties are summarized in Table 4. The Rv value is the NCO/OH
.ratio of the prepolymer.
The various physical properties were measured by conventional means. The values for the various poly-mer.ic polyols are the relative amounts used by weight, with the total being a normalized 100. The pot life relates the time from mixing the diamine curative with the prepolymer until the mixture is very difficult to pour.
.
- PHYSICAL PROPERTIES OF POLYURETHANES
' Ex~eriment A B
Polyethylene adipate 45 --Polypropylene adipate 55 --20 Polytetramethylene ether glycol -- 100 MDI Rv 2.0 __ DMMDI Rv . ~~ 1.9 Diamine * **
100% Modulus, psi 270 680 300% Modulus, psi 600 1600 500% Modulus, psi 2600 --Ultimate Tensile (psi) 4400 4300 Ultimate Elongation (%) 530 570 Crescent Tear (lb/in) 410 280 Compression Set (%) -- 16 30 Shore'A Hardness 75 79 Pot Life, Minutes 1 ~-* For experiment (A~ the diamine was bis(2~aminophenyl) '' -sulfide.
: ** For experiment (B), the diamine was 3,5-diaminobenzo-trifluoride.
~L~7~
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing rom the spirit or scope i of the invention.
.:'6
Background Art Diamines are especially valuable for curing various polyurethanes, particularly isocyanate terminated poly-urethane prepolymers. Aromatic diamine curatives are particularly valuable for curing aromatic isocyanate-terminated prepolymers (,to provide polyurethanes having enhanced age resistance in the presence of moisture and various liquid hydrocarbon fuels). However, many aromatic diamines typically react too fast with aromatic isocyanate-terminated prepolymers and therefore seriously inhibit their commercial significance. The 4,4'-methylene bis (2-chloroaniline), sometimes reerred to as MOCA, a well known diamine, is slower reacting at ' room temperature and should be considered one of the exceptions to such typical fast reacting aromatic diamines.
For such MOCA cured aromatic NCO-terminated prepolymers a catalyst is many times used to shorten the reaction time and enhance their commercial signifi-cance especially in the preparation of ure~hane films in solution systems.
Therefore, it is an,object of this invention to provide aromatic diamines suitable for curing aromatic isocyanate-terminated polyurethane prepolymers, methods of preparing such aromatic diamines and isocyanate-términated polyurethanes extended with aromatic diamines.
Disclosure And Practice Of Invention In'accordance with this invention? a cured poly-urethane is provided which is prepared by reacting (A) a diamine selected from at least one of the group , 7~
.2 consisting o~ 3,5-diam~nobenzotrifluoride, and ~is(:2-aminoph.enyl)sulf~de, with.'(B.~ an isocyanate~ter~inated prepolymèr prepared ~y the meth.od which co~prises reacting a poly~socyanate h.a~ing an i.socyanato function-ality o~ 2 to 3, wit~.a ~olyol com~rised o~ about 80 toabout lO.0 wei.~ht percent polymeric pol~ols selected from ~olyester polyols, polyether ~olyols and hydroxyl terminated unsaturated polymerlc polyols, and, correspond-ingly, about 20 to a~out 0 weight percent monomeric hydrocarbon d~ols hav~ng 3 to 8 carbon atoms; where the ratio of ~socyanato graups to hydroxyl ~roups of the polyol, or polyol mixture, is in the range of about 1~3!1 to about 5/1, and where the ratio of amino groups of said diamine to excess isocyanato groups of said hydroxyl groups is in the range of about 0.5/1 to a~out 1. 1~1. ' Rep~e.sentative examples of various monomeric polyols suitable for use in the preparation of the polyurethane are ethylene glycol, 1,3-propane diol, 1,4-butane diol, 1,5-pentane diol, 1,6-hexane diol and decamethylene glycol.
The polyurethane reaction mixtures used in this invention are typically liquid mixtures with the addition of a solvent commonly used to prepare poly-urethanes, if desired, and particularly flexible polyurethanes, by the well known one-shot prepolym~r or quasi-prepolymer techniques. The quasi-prepolymer method differ's from the prepolymer method in that only a portion of the pol~ol is initially reacted with the 3G polyisocyanate, with the remainde.r then added and reacted to form the prepQlymer. The prepolymer i5 then cured ox extended ~ith t~e d'i.a~ine.
The cura.t.i~e., pol~ols and polyisocyanates are typically reacted ~t te~pe.~atu~es in the range o about 20C, to about 15~C. and pre.f~er~ in t~.e range o~
about 2~C. to about lO~QG.
A sol~ent can ~e u~.-ed ~ith th.e'reaction mixture to facilitate its use ~n the form of a fluid mixture or 7~'7 solution, although it is generally preferred to use the reaction mixture with only a minor amount of solvent, if any. If a solvent is used, it can be added to form a mixture containing up to about 60 weight percent solvent based on the total mixture. A preferable mixture can contain from about 40 to about 95 weight percent solids. However, a higher or lower concentra-tion of solids might be used. When the solids concen-tration is low, the individual applications will tend to deposit a thin layer of polyurethane polymer and a large amount of the solvent will have to be removed during the curing process. A solids concentration of 45 weight percent or higher is generally desired if a solven~ is used.
Other methods generally known for the preparatiGn of polyurethane reaction mixtures with or withou~ the aid of solvents may also be used.
The diamine curative of this invention has a curative reactivity which allows improved processing for many commercial applications. Indeed, its typical curative reactivity with aromatic isocyanate-terminated polyurethane prepolymers enhances such a polyuréthane's commercial significance. The curative reactivity is valuable because it typically provides a shorter reaction time instead of the rather slow reaction provided by sterically hindered diamines like 4,4'-methylene-bis-(2-chloroaniline~, otherwise known as MOCA.
Thus, the diamine curatives of this invention can, if desired, eliminate the need o a catalyst such as the well-known tertiary amines, the tin salts of fatty acids, such as dibutyltin dilaurate and stannous octoate and accelerators such as ~ercaptobenzothiazole.
Xn the preparation o~ the polyurethanes by this invention, the polymeric polyols typically comprise at least one member selected from the group consisting of polyester polyols, polyether polyols, and hydroxyl-terminated unsaturated polymeric polyols. The hydroxyl-terminated unsaturated polymeric polyols typically have a molecular weight of from about 2000 to about ~000 and ~L7~8t~
a hydroxyl functionality o from about 2 to about 3.
The reactive hydrogen-containing material generally used, other than the hydroxyl-terminated unsaturated polymeric polyol, has a molecular weight in the range of from about 500 to about 5000, and usually from about 1000 to about 3000. (I the molecular weight of the reactive hydrogen-containing material is too low, the polyurethane will not have suicient elasticity.) Generally, the polyester polyols are the preferred 10 active hydrogen-containing material where high strength and solvent resistance are desired.
Representative examples of polyester polyols are the condensation products of low molecular weight polyols wlth an organic polycarboxylic acid or anhydride.
15 ~epresentative low molecular weight polyols are glycols such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, decamethylene glycol, etc.
Representative examples o the organic dicarboxylic acids that can be used are succinic acid, glutaric 20 acid, adipic acid, phthalic acid, terephthalic acid, isophthalic acid, suberic acid, sebacic acid, pimelic acid and azelaic acid. The anhydrides of such acids can be used in place of the acid. If desired, rom about 1 to 20 percent by weight of a triol or higher 25 polyfunctional polyol or polyfunctional acid can be present to produce branching in the polyurethane polymer.
Further examples o polyesters are caprolactone polyesters. The caprolactone polyesters are substan-tially linear, hydroxyl-terminated polymers prepared by 30- reactin~ a caprolactone having 6 to 8 carbon atoms, preferably 6 carbon atoms, with a glycol having 4 to 7 carbon atoms and preferably 4 to 6 carbon atoms.
Various suitable caprolactones include ~ -caprolactone, zeta-caprolactone and eta-capro-t 35 lactone. Alkyl substituted caprolactones can be used with alk~l substituents containing 1 to 2 carbon atoms selected from methyl and ethyl radicals such as methyl ~ -caprolactone. Desirably, the caprolàctone polyester has a molecular weight in the range of about 800 to about 3500, preferably about 1200 to about 3000, with - corresponding hydroxyl numbers in the range of about 140 to about 32 and about 95 to about 37, respectively.
Polyether polyols useful in preparing the poly-urethanes of this invention can be prepared by poly-merizing or copolymerizing alkylen~ oxides, such as ethylene oxide, propylene oxide, and butylene oxides, by polymerizing or copolymerizing the low molecular weight glycols, or by the reaction of one or more such alkylene oxides with the glycols or with triol, or with a polycarboxylic acid, such as phthalic acid. The polyether polyols include polyalkylenearyl ether glycols or triols, polytetramethylene ether glycols, polyalkylene ether-thioether glycols or triols and alkyd resins.
Generally the polytetramethylene ether glycols are the preferred polyether glycols.
It is usually preferred that the hydroxyl-terminated unsaturated polymeric polyol has a molecular weight of 20 from about 2000 to about 4000 and a corresponding hydroxyl number of from about 50 to about 25. The hydroxyl-terminated unsaturated polymeric polyols used in this invention are unsaturated polymers of the type prepared by polymerizing unsaturated monomers comprising 25 from about 70 to about 100 percent conjugated dienes selected from the group consist-ing o 1,3-butadiene and isoprene and up to abut 30 percent styrene with the aid of organic peroxy catalysts to provide polymers which are gen~rally terminated at both ends of their chain 3~ with hydroxyl groups and have a hydroxyl functionality of from about 2 to about 3 and usually from about 2.1 to about 2,8. The preferred hydroxyl-containing poly-meric polyols are polybutadiene polyols, polyisoprene polyols~ butadiene-sty~ene copolymer polyols having about 70 to 90 percent units derived from butadiene and about 30 to 10 percent units derived from styrene and also butadienè-acrylonitrile copolymer polyols.
The organic polyisocyanates used in this invention having 2 to 3 isocyanato groups particularly include various organic diisocyanates, dimers and trimers thereof, and their mixtures as well as polyisocyanates having 2.3 to 2.7 isocyanato groups. The organic polyisocyanates can be aromatic, aliphatic or cyclo-aliphatic or combinations of these types.
Representative examples of such polyisocyanatesinclude the toluene diisocyanates, m-phenylene diiso-cyanate, 4-chloro-1,3-phenylene diisocyanate, 4,4'-tetramethylene diisocyanate, 1,6-hexamethylene diiso-10 ' cyanate, 1,10-decamethylene diisocyanate, 1,4-cyclo-hexylene diisocyanate, 4,4'-methylene-bis (cyclo-hexylisocyanate), 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate and 1,5-tetrahydronaphthalene diisocyanate and mixtures of such diisocyanates For ~he purposes of the present invention, the toluene diisocyanates,' diphenylmethane-4,4'-diisocyanate, 3,3'-dimethyI-4,4'-bis-phenylene diisocyanate, 4,4'-methylene-bis(cyclo-hexylisocyanate~ and 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate are preferred. For convenience, these diisocyanates are sometimes referred to as TDI, ~DI, TODI, H12 MDI and DMMDI, respectively.
~ aricus non-reactive solvents known to those skilled in the polyurethane art can be used for the preparation of the prepolymer solùtions and polyurethane reaction mixtures, if a solvent is desi~ed. ~epresenta-tive ex~mples of the solvents are aromatic solvents such as benzene, xylene and toluene and ~he liquid lower ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone. If the polyurethane reaction ~ixtuxes are to be used to prepare the cured polyurethanes in confined areas which are subject to explosive hazardsj nonflammable polyurethane solvents can be used to form nonflammable polyurethane reaction mixtures. Mixtures of solvents may also be used to obt~in sat~sfactory spreading properties and evaporation rates when the polyuret~ane spray composition is applied to a polymeric surface.
To enhance the cured polyurethane's hydrolysis resistance, about 1 to about 15, preferably about 2 to ~74~
about 5, weight percent of an epoxy resin and at least suEficient to give an excess of epoxide groups relative to the total excess of amino groups of the diamine curative over the said isocyanato groups might be used.
Thus, for such a modification an excess of epoxide groups is required over the amino groups of the curative, such as at least about 5 to about 50 equivalent percent excess, based on two epoxy groups per amino (-NH2) group, to provide a polyurethane composition containing sufficient free epoxide groups.
Hydrolysis resistance is typically determined by immersion in distilled wa~er at 158F. A substantial retention of tensile strength and elongation after 1~
days immersion can be related to a substantial resistance to hydroly5is. The tensile and elongation are normally determined at about 25C. by methods typically used by those skilled in the art.
Preferred resins for this invention are derived from epichlorohydrin and 2,2'-bis(4-hydroxyphenyl) propane with an epoxide equivalency of about 150 -to about 220, preferably about 175 to about 210. Resins which are pourable liquids at about 25C. are preferred but others can be used in solution. Typical resins are those obtainable under the tradenames Epon 828 and Epon 1001 from the Shell Chemical Company.
. The practice of this inven~ion is further illus-trated by reference to the following examples which are intended to be representatîve rather than restrictive of the scope of the invention. Unless otherwise indi-c~ted, all parts and percentages a~e by weight.
- EXoMP*E I
Cured polyurethanes were prepared by reacting various diamines of this invention with various iso-cyanate-terminated polyurethane prepolymers.
The prepolymers were p~epared by reacting an excess of various diisocyanates with various polymeric polyether and polyester polyols. The diisocyanates were selected from 4,4'-diphenyl methane diisocyanate .' - (MDI) and 3,3'-dimethyl-4,4'-diisocyanato diphenyl 1~478 ~
methane (DMMDI). The various polymeric polyols were selected from polyethylene adipate with a molecular weight (mw) of about 1000, polypropylene adipate (mw 2000), and polytetramethylene ether glycol (mw 2000).
5The experiments and physical properties are summarized in Table 4. The Rv value is the NCO/OH
.ratio of the prepolymer.
The various physical properties were measured by conventional means. The values for the various poly-mer.ic polyols are the relative amounts used by weight, with the total being a normalized 100. The pot life relates the time from mixing the diamine curative with the prepolymer until the mixture is very difficult to pour.
.
- PHYSICAL PROPERTIES OF POLYURETHANES
' Ex~eriment A B
Polyethylene adipate 45 --Polypropylene adipate 55 --20 Polytetramethylene ether glycol -- 100 MDI Rv 2.0 __ DMMDI Rv . ~~ 1.9 Diamine * **
100% Modulus, psi 270 680 300% Modulus, psi 600 1600 500% Modulus, psi 2600 --Ultimate Tensile (psi) 4400 4300 Ultimate Elongation (%) 530 570 Crescent Tear (lb/in) 410 280 Compression Set (%) -- 16 30 Shore'A Hardness 75 79 Pot Life, Minutes 1 ~-* For experiment (A~ the diamine was bis(2~aminophenyl) '' -sulfide.
: ** For experiment (B), the diamine was 3,5-diaminobenzo-trifluoride.
~L~7~
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing rom the spirit or scope i of the invention.
.:'6
Claims (4)
Claims
1. A polyurethane prepared by reacting at least one aromatic diamine selected from the group consisting of 3,5-diaminobenzotrifluoride and bis(2-aminophenyl) sulfide with an isocyanate-terminated prepolymer prepared by reacting a polyisocyanate having an isocyanato functionality of 2 to 3, with a polyol comprised of about 80 to about 100 weight percent polymeric polyols selected from polyester polyols, polyether polyols and hydroxyl terminated unsaturated polymeric polyols, and correspondingly, about 20 to about 0 weight percent monomeric hydrocarbon diols having 3 to 8 carbon atoms, where the ratio of iso-cyanato groups to hydroxyl groups of the polyol, or polyol mixture, is in the range of about 1.3/1 to about 5/1, and where the ratio of amino groups of said diamine to excess isocyanato groups of said hydroxyl groups is in the range of about 0.5/1 to about 1.1/1.
2. The polyurethane of claim 1 where said aromatic diamine is 3,5-diaminobenzotrifluoride.
3. The polyurethane of claim 1 where said aromatic diamine is bis(2-aminophenyl) sulfide.
4. The polyurethane of claim 1 where said polyiso-cyanates are selected from at least one of the toluene diisocyanates, m-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4,4'-tetra-methylene diisocyanate, 1,6-hexamethylene diiso-cyanate, 1,10-decamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4'-methylene-bis (cyclohexylisocyanate), 3,3'-dimethyl-4,4'-diphenyl methane diisocyanate and a 1,5-tetrahydro-naphthalene diisocyanate; where said monomeric polyols are selected from at least one of ethylene glycol, 1,3-propane diol, 1,4-butane diol, 1,5-butane diol, 1,6-hexane diol and decamethylene glycol, where said polymeric polyols are selected from at least one of hydroxy-terminated unsaturated polymeric polyols having a molecular weight of from about 2000 to about 4000 and a hydroxyl func-tionality of from about 2 to about 3 and polyester and polyether polyols having a molecular weight in the range of about 1000 to about 3000.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US1369879A | 1979-02-21 | 1979-02-21 | |
| US13,698 | 1979-02-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1174787A true CA1174787A (en) | 1984-09-18 |
Family
ID=21761257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000343069A Expired CA1174787A (en) | 1979-02-21 | 1980-01-04 | Cured polyurethanes |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS55112230A (en) |
| CA (1) | CA1174787A (en) |
| DE (1) | DE3006562A1 (en) |
| FR (2) | FR2449698A1 (en) |
| GB (1) | GB2042567B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101260181B (en) * | 2008-04-09 | 2010-10-13 | 南通华盛高聚物科技发展有限公司 | Melt spinning spandex interlinkage agent and producing method thereof |
| JP7230525B2 (en) * | 2019-01-22 | 2023-03-01 | 株式会社デンソー | Curable composition and electronic device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1520570C3 (en) * | 1962-10-15 | 1978-10-05 | E.I. Du Pont De Nemours And Co., Wilmington, Del. (V.St.A.) | Process for the production of polyurethane elastomers with improved cold resistance |
| US3456037A (en) * | 1964-12-14 | 1969-07-15 | Du Pont | Polyurethane-polyureas |
| US3926919A (en) * | 1973-07-23 | 1975-12-16 | Goodyear Tire & Rubber | Polyurethanes chain-extended with 2,2{40 -diaminodiphenyldisulfide |
| US3897400A (en) * | 1973-12-26 | 1975-07-29 | Goodyear Tire & Rubber | Polyurethane cured with an aromatic monosulfide diamine |
| US4017464A (en) * | 1976-02-05 | 1977-04-12 | The Goodyear Tire & Rubber Company | Polytetramethylene ether urethane cured with 2,2'-diaminodiphenyl disulphide |
-
1980
- 1980-01-04 CA CA000343069A patent/CA1174787A/en not_active Expired
- 1980-01-16 GB GB8001525A patent/GB2042567B/en not_active Expired
- 1980-02-11 FR FR8002915A patent/FR2449698A1/en active Granted
- 1980-02-19 JP JP1966680A patent/JPS55112230A/en active Pending
- 1980-02-21 DE DE19803006562 patent/DE3006562A1/en active Granted
-
1982
- 1982-09-22 FR FR8215965A patent/FR2511691B1/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3006562A1 (en) | 1980-09-04 |
| GB2042567A (en) | 1980-09-24 |
| FR2449698A1 (en) | 1980-09-19 |
| DE3006562C2 (en) | 1989-04-20 |
| FR2511691B1 (en) | 1986-11-21 |
| GB2042567B (en) | 1983-03-09 |
| FR2511691A1 (en) | 1983-02-25 |
| JPS55112230A (en) | 1980-08-29 |
| FR2449698B1 (en) | 1984-01-13 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |