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
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/02—Polycondensates containing more than one epoxy group per molecule
  • C08G59/04—Polycondensates containing more than one epoxy group per molecule of polyhydroxy compounds with epihalohydrins or precursors thereof
  • C08G59/06—Polycondensates containing more than one epoxy group per molecule of polyhydroxy compounds with epihalohydrins or precursors thereof of polyhydric phenols
  • C08G59/066—Polycondensates containing more than one epoxy group per molecule of polyhydroxy compounds with epihalohydrins or precursors thereof of polyhydric phenols with chain extension or advancing agents
• • 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
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/02—Polycondensates containing more than one epoxy group per molecule
  • C08G59/04—Polycondensates containing more than one epoxy group per molecule of polyhydroxy compounds with epihalohydrins or precursors thereof
  • C08G59/06—Polycondensates containing more than one epoxy group per molecule of polyhydroxy compounds with epihalohydrins or precursors thereof of polyhydric phenols

Definitions

• the invention relates to internally flexibilized advanced epoxy resin compositions flexibilized with internal polybutylene glycol units, and a process for the preparation of such internally flexibilized advanced epoxy resins.
• the invention further relates to coatings prepared from such internally flexibilized advanc epoxy resins, such coatings are useful in cathodic electrodepositions, powder coating applications, marine and maintenance and in food and beverage applications.
• Advanced epoxy resin compositions are used in a variety of applications, such as in coatings compositions in several fields, for example in cathodic electrodeposition, powder coating of pipes and structural elements, in liquid coating compositions for food and beverage cans and marine and maintenance applications.
• Advanced epoxy resin based coatings have advantageous properties such as adhesiveness, strength, hardness and chemical resistance.
• cured advanced epoxy resin compositions suffer from a lack of flexibility, which can have a negative effect on other properties such as protection of substrates from corrosion.
• Cathodic electrodeposition of a film composed of an amine modified epoxy resin, crosslinker, pigment and optionally other resinous components onto an electrically conductive article is an imoortant industrial process. It constitutes the usual manner i which automobile and truck bodies as well as appliance and other large complex metallic surface bodies are protected against corrosion.
• the conductive article, article to be coated forms one electro ⁇ e and is • mmersed a coating Dath made from an aqueous diSDersion of the fi- ⁇ . forming amine modified epoxy r esm and other comoonents.
• An electrical current is oassed between the article and the counter electrode in the electrodeposition bath.
• a charge on the article causes deposition of the resins and other components in tne batn on the article to be coated so as to produce the electrodeposited film
• the deposited film is then baked or otherwise hardened to yield a coating of a substantially uniform thickness and protective characteristics
• European Patent Application 300,504A discloses the preparation of flexibilized epoxide compounds by reacting an aromatic diol with diepoxides which are diglycidyl ethers of aromatichydroxy compounds, or a b ⁇ s-(lab ⁇ le hydrogen functiona zed) alkoxy arylene compound
• European Patent Application 315, 164 discloses a coating resin composition which comprises the reaction product of a diepoxide compound which is a diglycidyie ther of a bisphenol A (b ⁇ s-(4-hydroxy phenyl)propane) initiated polyalkylene oxide, a bisphenol, optionally a bisphenol diglycidyie ther, and an amine, having an active nydrogen It is disclosed therein that the bisphenol A initiated polyalkylene oxide diepoxide r es_lts in an improved electrodeDOSi tion coating
• Commonly assigned patent application EP 253,405 discloses an advanced epoxy cationic resin D ⁇ epar ed by reacting
• the resins in the coating have a low viscosity to facilitate processing and control of the coating thickness. It is also desirable that such coatings demonstrate low water permeability as this property is important in the inhibition of corrosion. Additionally it is desirable that such coatings demonstrate good flexibility.
• the problem is that as the resin viscosity is lowered and the coating flexibility is increased, the water permeability of the coating is usually also increased.
• What i «. needed are resins for use in coatings, including electrodeposition coatings, which exhibit lo _r viscosities, result in coatings with higher flexibility and lower water permeability. What is further needed, is an advanced resin which has efficiently incorporated therein the flexibilizing agents. What is further needed is a process which allows efficient incorporation of the fiexibiiizing agent into the backbone of the advanced epoxy resin.
• the invention relates to flexibilized advanced epoxy resins comprising the residue of A. one or more polyglycidyl ethers of a water or di- or trihydroxy substituted C ⁇ _6 hydrocarbon initiated polybutylene glycol;
• each polyaromatichydroxy compound is bound to at least one polyglycidyl ether of polybutylene glycol or to at least one polyglycidyl ether of a polyaromatichydroxy compound through the reaction product of an aromatichydroxy moiety with a glycidyl ether moiety; most of the polyglycidyl ethers of polyaromatichydroxy compounds are bound to at least one polyaromatichydroxy compound through the reaction product of glycidyl ether moiety and an aromatichydroxy moiety; each residue of a polyglycidyl ether of polyaromatichydroxy compound is bound to at least one polyaromatichydroxy compound through the reaction of a glycidyl ether moiety and an aromatichydroxy moiety;
• the mole ratio of polyaromatichydroxy compound to polyglycidyl ether of polybutylene glycol is at least 2.0 to 1.0; and sufficient polyglycidyl ether of polyaromatichydroxy compound is present in the resin such that the terminal moieties of the resin are glycidyl ether moieties from the polyglycidyl ethers of polyaromatichydroxy compounds.
• the invention is a process for the preparation of such flexibilized advanced epoxy resins comprising
• A reacting a polyglycidyl ether of a di- or tn- hydroxy C ⁇ _6 hydrocarbon or water initiated polybutylene glycol with two or more moles of a polyaromatichydroxy compound per mole of polyglycidyl ether of polybutylene glycol under conditions such that substantially all of the glycidyl ether moieties of the polyglycidyl ether of polybutylene glycol react with aromatichydroxy moieties of the polyaromatichydroxy compounds;
• reaction product from A thereafter reacting the reaction product from A with an excess of one or more polyglycidyl ethers of polyaromatichydroxy compounds, optionally one or more polyaromatichydroxy compounds, and optionally one or more chain terminators, under conditions such that the aromatichydroxy moieties react with the glycidyl ether moieties wherein the terminal functional moieties of the product are glycidyl ether moieties.
• the invention relates to flexibilized advanced epoxy resins prepared by the above-described process
• the invention is directed to advanced epoxy cationic resins having a charge density of from 0.2 to 0.6 milliequivalents of cationic charge per gram of resi n, wherein the terminal epoxy moieties of the above-described resins have been reacted with a nucleophile and treated to render the resulting moieties cationic.
• the advanced epoxy resins of the invention demonstrate improved flexibility and improved corrosion protection of substrates coated with such compositions as compared to conventional resins.
• the flexibilized advanced epoxy resin compositions of the invention and the process for preparation of the resin also demonstrate a more efficient incorporation of the flexibilizing agent into the backbone of the resin.
• the flexibilized advanced eooxy resins of the invention demonstrate improved elongation and im ⁇ a resistance along with exceptional combination of elongation, impact resistance, and corrosion resistance as compared to conventional resins.
• a major advantage of the invention is the efficient incorporation of an improved fiexibilizing agent into tne internal backbone of the advanced eooxy resins
• the backbone of the flexibilized eooxy resin of this invention contains at least one unit of the flexibilizing component in its interior.
• the fiexibiiizing unit is the residue of a polyglycidyl ether of a water or di- or ⁇ ri- hydroxy substituted C ! .6 ny rocarDon initiated polybutylene glycol, which means herein that the glycidyl ether moieties of such compound have been reacted with aromatic hydroxy I groups so as to incorporate such polybutylene glycol into the backbone of the flexibilized advanced epoxy resins.
• the flexibilizing agent is prepared by reacting water or a di- or tri- hydroxy substituted C- .6 hydrocarbon with butylene oxide units, so as to react the hydroxy units or water with the butylene oxide, thereby forming a polybutylene glycol with a central unit comprising oxygen or the residue of the di- or tri- hydroxy substituted C ⁇ _6 hydrocarbon. Thereafter the terminal hydroxy moieties of the polybutylene glycol are reacted with an epihalohydrin to form terminal glycidyl ether moieties. Such reactions are well-known to those skilled in the art.
• Polybutylene glycol as used herein refers to compounds which contain more than one butylene oxide unit within the backbone, and includes compounds wherein one butylene oxide unit is added to each active hydrogen unit of the initiator.
• the initiators for the flexibilizing unit are water, ethylene glycol, propyiene glycol, butane diols, such as 1 ,4 butane diol, trimethyol propane, neopentylglycol and glycerol.
• the most preferred initiator is water.
• the polyglycidyl ether of polybutylene glycol has a molecular weight of 1 0 or greater, most preferably 200 or greater and most preferably 300 or greater.
• the polyglycidyl ether of polybutylene glcyol has a molecular weight of 2000 or less, more preferably 1000 or less, and most preferably 600 or less.
• the molecular weights referred to here are number average molecular weights.
• the flexibilized advanced epoxy resins of this invention preferably contain 5 percent or greater by weight of the residue of the glycidyl ethers of polybutylene glycol in the backbone, and more preferably 10 percent or greater.
• the flexibilized advanced epoxy resins of this invention contain 50 percent or less by weight of the residue of polyglycidyl ethers of polybutylene glycol in the backbone, more preferably 30 percent or less by weight.
• the glycidyl ethers of polybutylene glycol correspond to formula 1 :
• R is independently in each occurrence hydrogen, methyl or ethyl with the proviso that for each
• R are methyl or one R is ethyl and the other is hydrogen; T is independently in each occurrence a direct bond or the moiety
• R' is independently in each occurrence hydrogen or a C alkyl moiety
• Z is independently in each occurrence oxygen or
• X is independently in each occurrence a straight or branched chain C ⁇ _e alkyl moiety; a is independently in each occurrence a positive real number of 1 or greater; b is independently in each occurrence 2 or 3 Z is preferably oxygen.
• X is or efer ably a straight or branched chain C ⁇ ._ ⁇ alkyl moiety.
• a is a real number of from 1 to 16; more preferably from 1 to 8 and most preferably of from 2 to 5.
• b is 2.
• the initiator used in this invention preferably is water or corresponds to Formula 2:
• polyglycidyl ethers of polybutylene glycol are reacted with polyaromatichydroxy compounds
• the polyaromatichydroxy hydrocarbons have two or more aromatic bound hydroxy groups
• the polyaromatichydroxy compounds can be further substituted on the hydrocarbon backbone by halogen moieties.
• Dolyaromatichydroxy com ⁇ ounos are the bispnenols, halogenated bisDhenols, hydrogenated Dispnenois, ana novolac resins, • e the reaction product of Dhenols and simple aldehydes, preferably formaldehyde ana hydroxy benzaidehyde
• Preferred polyaromatichydroxy compounds useful in this invention correspond to formula 3: A — (OH) c
• Ar is an aryl moiety; aryl moiety substituted with an alkyl or halo moiety; a polyaryl moiety wherein the aryl moieties are connected by direct bonds, alkylene, haloalkylene, cycloalkylene, carbonyl, sulfonyl, sulfinyl, oxygen, or sulfur moieties, such polyaryl moieties being optionally substituted with an alkyl or halo moiety; or the oligomeric reaction product of an aldehyde and phenol; and c is a positive real number greater than 1.
• More preferred polyaromatichydroxy compounds include those corresponding to formulas 4 and 5:
• R2 is separately in each occurrence C1-3 alkyl or a halogen
• R3 is separately in each occurrence G.-o alkylene, Ci.fo haloalkylene, C_..**o cycloalkylene, carbonyl, sulfonyl, sulfinyl, oxygen, sulfur, a direct bond or a moiety corresponding to the formula
• R ⁇ is independently in each occurrence C ⁇ _ ⁇ o alkylene or C5.50 cycloalkylene;
• Q is independently in each occurrence a C-.no hydrocarbyl moiety
• Q' is independently in each occurrence hydrogen, cyano, or a C-,-_. alkyl group; m is independently in each occurrence an integer of 0 to 4; m' is independently in each occurrence an integer of from 0 to 3; p is a positive real number of 0 to 10.
• R 3 is preferably C].3 alkylene, C 1 -3 haloalkylene, carbonyl, sulfur, or a direct bond.
• R 3 is most preferably propylene.
• R 2 is preferably methyl, bromo or chloro; and most preferably methyl or bromo.
• R 4 is preferably C1.3 alkylene or polycyclic moiety corresponding to the formula
• t is an average number from 1 to 6 inclusive, preferably 1 to 3, most preferably 1.
• m and m " are independently an integer of 0 to 2.
• p represents an average number, as the compounds to which it refers are generally found as a mixture of compounds with a dist ⁇ Dution of the units to which p refers.
• Cycloalkylene as used herein refers to monocyclic and poiycyciic hydrocarbon moieties.
• the most preferred class of polyar omatichdr oxy compounds are the dihydroxy phenols.
• Preferable dihydroxy phenols include those whicn contain substituents that are ⁇ on- reactive with the phenolic groups.
• Illustrative of such phenols are 2,2-bis(3,5-dibr omo-4- hydroxyphenyl) propane; 2,2-bis(3,5-dibromo-2,4'-hydroxyphenyl) propane; 2,2-bis(4- hydroxyphenyl) propane; 2,2-bis(2,4'-hydroxyphenyl) propane; 2,2-bis(3,5-dichloro-4- hydroxyphenyl) propane; 2,2-bis(3,5-dichloro-2,4'-hydroxyphenyl) propane; bis (4- hydroxyphenyl) methane; bis (2,4'-hydroxyphenyl) methane; 1 ,1-bis(4-hydroxyphenyl)-1- phenyl ethane; 1 ,1-bis(2,4'
• haloalkyl refers to a compound with a carbon chain and one or more of the hydrogens replaced with a halogen, and includes compounds where all of the hydrogen atoms have been replaced by halogen atoms.
• Alkylene as used herein refers to a divalent alkyl moiety.
• hydrocarbyl means any aliphatic, cycloaliphatic, aromatic, aryl substituted aliphatic or cycloaliphatic, or aliphatic or cycloaliphatic substituted aromatic groups.
• the aliphatic groups can be saturated or unsaturated.
• hydrocarbyloxy means a hydrocarbyl group having an oxygen linkage between it and the carbon atom to which it is attached.
• Polyaryl moiety as described herein refers to compounds which contain more than one aromatic ring which may be fused, bonded by direct bond, or connected by alkylene, haloalkylene, cycloalkylene, carboxyl, sufonyl, sulfinyl, oxygen or sulfur moieties.
• residue refers to the portion of a starting material remaining in the final product after completion of the reaction.
• residue of a polyaromatichydroxy compound means herein that a polyaromatichydroxy compound has been incorporated into the backbone of the flexibilized advanced epoxy resin wherein the aromatichydroxy moieties have reacted with glycidyl ether moieties of the glycidyl ether of polybutylene glycol, or the glycidyl ether moieties of a glycidyl ether of an aromaticnydroxy compound.
• the polyaromatichydroxy compounds are nominally dihydroxy aromatic compounds meaning that the dihydroxy compounds are a mixture of compounds resulting from the preparation process, and on average the compounds present have near two hydroxy moieties per molecule.
• the residue of polyglycidyl ethers of poiyaromatic hydrocarbon means heret n that at least one of the glycidyl ether moieties has reacted with an aromatichydroxy moiety, wherein the polyaromatichydroxy compound may be further reacted with a polyglycidyl ether of a polybutylene glycol
• the resins of this invention preferably have terminal glycidyl ether moieties which are derived from the glycidyl ethers of polyaromatichydroxy compounds
• a small portion of the flexibilized advanced epoxy resins of this invention contain polyglyciyl ethers of poiyaromatic hydrocarbons that have not reacted with an aromatichydroxy moiety. Generally these materials are not removed prior to utilization
• Polyglycidyl ether of a polyaromatichydroxy compound means a hydrocarbon compound containing one or more aromatic moieties, wherein more than one epoxy (1 ,2 glycidyl ether) moiety is bound to the aromatic moieties In another embodiment it refers to a mixture of compounds which contains, on average, more than one epoxy moiety per molecule bound to aromatic moieties
• Polyglycidyl ether of a polyaromaticnydroxy compound as used herein includes partially advanced epoxy resins i e the reaction o ⁇ a polyglycidyl ether of a polyaromatichydroxy compound and one or more polyaromatichydroxy compounds, whe r e ⁇ n the reaction product has an average of more than one unreacted epoxide unit per molecule
• Polyglycidyl ethers of a polyaromatichydroxy compounds are prepared by reacting an epihalohyd ⁇ n with a polyaromatichydroxy compound
• the preparation of such compounds is well known in the art See Kirk-Othmer Encyclopaedia of Chemical Technology 3rd Ed Vol 9 pp 267-289, "The Handbook of Epoxy Resins" by H. Lee and K. Neville (1967) McGraw Hill, New York, and US Patents 2,633,458, 3,477,990; 3,821 ,243, 3,907,719, 3,975,397; and 4,071 ,477
• Y is a halogen, preferably cnloro or bromo, and most preferably cnloro, and R is as previously defined
• the polyglycidyl ethers of polyaromatichydroxy compounds useful in the invention preferably correspond to formula 7
• R' is preferably hydrogen or methyl.
• c is 5 or less, more preferably from 1 to 3.
• polylycidyl ethers of polyaromatichydroxy compounds more preferably correspond to one of formulas 8 or 9:
• R 1 , R 2 , R 3 , R 4 , m, and m' are as defined previously; ⁇ s a positive real number of 0 to 40, and s is a positive real number of 0 to 10
• r is a positive real number of 0 to 10, and most preferably 1 to 5
• s is a positive real number of 0 to 8; and most preferably 1 to 4. All of the variables referred to herein as positive real numbers, i.e r and s, are average numbers as the compounds referred to contain a distribution of units
• Preferable polyglycidyl ethers of polyaromatichydroxy compounds are the glycidyl ethers of dihydroxy phenols, bisphenols, halogenated bisphenols, alkylated bisphenols, t ⁇ sphe ⁇ ols, phenol-aldehyde novolac resins, halogenated phenol-aldehyde novolac resins, alkylated phenol-aldehyde novolac resins, hydrocarbon-phenol resins, hydrocarbon- halogenated phenol resins, or hydrocarbon-alkylated phenol resins, or any combination thereof and the like
• Even more preferable polyglycidyl ethers of polyaromatichydroxy compounds include, for example, the diglycidyl ethers of resorcinol, catechol, hydroquinone, bisphenol, bisphenol A, bisphenol AP (1 , 1-b ⁇ s(4-hydroxylphenyl)-1-phenyl ethane), bisphenol F, bisphenol K,
• the advanced flexibilized epoxy resins of this invention can contain the residue of a chain terminator
• a chain terminator is a material which has only one reactive moiety containing an active hydrogen atom Such chain terminator functions to reduce the molecular weight of the proposed material and are well known in the art.
• An example of a preferable chain terminator is paratertiarybutyl phenol
• the advanced flexibilized resins of this invention correspond to formula 10
• E is independently in each occurrence a moiety according to one of the formulas
• d is independently in each occurrence a number of from 0 to 2; 5 e is independently in each occurrence 0 or 1 ; and Ar, R, T, Z, X, a, b and c are as defined hereinbefore.
• the flexibilized advanced epoxy resin are converted to flexibilized advanced epoxy cationic resins which have a charge density 0 of from 0.2 to 0.6 milliequivalents of cationic charge per gram of resin.
• Such resins are prepared by reacting the terminal glycidyl ether moieties with a nucleophile and thereafter converting the reaction product to cationic species.
• Nucieophiles useful for performing this reaction are well-known to those skilled in the art.
• Preferred nucieophiles are monobasic neteroaromatic nitrogen compounds, tetraflower alkyl) thi ⁇ ureas, sulfides corresponding .to formula 1 1 : ; R6-S-R6 1 1
• R 6 is independently i n each occurrence lower alkyl, hydroxy lower alkyl or two of R ⁇ may combine as one 3 to 5 carbon atom alkylene radical thereby forming a heterocycloalkylene moiety,
• R 7 is independently in each occurrence hydrogen, hydroxyalkyl, lower alkyl, aralkyl or aryl;
• R 8 is independently in each occurrence hydrogen, lower alkyl, hydroxy lower alkyl, the moiety
• R1 1 or two of R 8 may combine to form an alkylene radical having from 3 to 5 carbon atoms; R 9 independently in each occurrence lower alkyl, hydroxy lower alkyl or aryl, R 1 0 is independently in each occurrence a C 2- ⁇ o alkylene group, R 1 1 is independently in ea"ch occurrence lower alkyl
• the nucleophile is an amine, more preferably a primary or secondary amine
• nucleophilic compounds are py ⁇ dine, nicotinamide, qumoline, isoquinoline, tetramethyl thiourea, tetraethyl thiourea, hydroxyethylmethyl sulfide, hydroxyethylethyl sulfide, dimethyl sulfide, diethyl sulfide, di-n-propyl sulfide, methyl- ⁇ -propyl sulfide, methylbutyl sulfide, dibutyl sulfide, dihydroxyethyl sulfide, bis-hydroxybutyl sulfide, t ⁇ methylene sulfide, thiacyclohexa ⁇ e, tetrahydrothiophene, dimethyl amine, diethyl amine, dibutyl amine, 2-(methy!am ⁇ no)ethanol, diethanolamine, N-methylpipe ⁇ dine, N- eth
• G is independently in each occurrence a moiety according to one of the formulas:
• A- is the anion of an acid as described hereinafter; and Ar, B, R, R7, R8 f T, Z, X, a, b, c, d and e are as described hereinbefore.
• the flexibilized advanced epoxy resins of this invention preferably exhibit a weight average molecular weight of 900 or greater, more preferably 1200 or greater, and most preferably 1500 or greater.
• the flexibilized advanced epoxy resins of this invention preferably have a molecular weight of 50,000 or less, more preferably 30,000 or less, anc 1 most preferably 20,000 or less.
• the flexibilized advanced epoxy resins of this invention prefers jiy have an epoxy equivalent weight (EEW) of 450 or greater, more preferably 600 or greater, and most preferably 800 or greater.
• the flexibilized advanced epoxy resins of this invention preferably have an EEW of 5,000 or less, more preferably 4,000 or less, and most preferably 3,000 or less.
• the inventors have recognized that tne rea ⁇ ivity of a polyglycidyl ether of a polybutylene glycol with a polyaromatichydroxy compound is much iower than the reactivity of a polyglycidyl ether or a polyaromatichydroxy compound with a polyaromatichydroxy compound. Therefore, unless the process conditions are carefully chosen, it is difficult to efficiently incorporate the polyglycidyl of a polybutylene glycol into the internal structure of and advanced epoxy resin.
• the process of this invention involves first rea ⁇ ing the glycidyl ether of a water or di- or tri- hydroxy substituted C-.e hydrocarbon initiated polybutylene glycol with the polyaromatichydroxy compound under conditions such that substantially all of the glycidyl ether moieties on the polyglycidyl ether of the polybutylene glycol are rea ⁇ ed with aromatichydroxy groups.
• the reaction product is reacted with a polyglycidyl ether of a polyaromatichydroxy compound under conditions such that the terminal aromatichydroxy moieties of the reaction product rea ⁇ with the glycidyl ether moieties of the polyglycidyl ether of the polyaromatichydroxy compound, such that the terminal groups of the flexibilized epoxy resin are primarily glycidyl ether moieties.
• additional polyaromatichydroxy compounds may be present in the second step to facilitate the further advancement of the flexibilized epoxy resin.
• a known chain terminator may be present in the rea ⁇ ion mixture in small quantities.
• the polyglycidyl ether of the polybutylene glycol is conta ⁇ ed with the polyaromatichydroxy compound neat, in the absence of solvent, or in the presence of an organic solvent which demonstrates low affinity for water.
• solvents include aromatic hydrocarbons, mixtures of aromatic hydrocarbons and alkanols, glycol ethers and ketones.
• epoxy resin advancement catalyst such as compounds containing amine, phosphine, heterocyclic nitrogen, ammonium, phosphonium, arsonium, or sulfonium moieties.
• Preferred catalysts are the phosphonium compounds.
• the catalyst is a phosphonium or an amine
• preferably 500 ppm (parts per million) or more of the catalyst is present, more preferably 700 ppm or more.
• such catalyst is present in amounts of 3,000 ppm or less, more preferably 2000 ppm or less.
• the reaction mixture is heated until an exotherm begins, generally at from 140 to 150°C
• the temperature of the mixture is increased at a rate of from 1 to 2°C per minute until the exotherm begins.
• the temperature is maintained at levels at which the rea ⁇ ion continues, until the reaction is completed.
• a rea ⁇ ion generally stops itself.
• the reaction may be quenched by cooling.
• the reaction time is dependent upon the concentration of catalyst, materials present, presence of solvent and the rea ⁇ ivity of materials.
• rea ⁇ ion times are 15 minutes or greater, more preferably 30 minutes or greater.
• rea ⁇ ion times are 4 hours or less, and more preferably 3 hours or less
• the amount of polyaromatichydroxy compound conta ⁇ ed with the polyglycidyl ether of the polybutylene glycol is sufficient to rea with ali of the glycidyl ether moieties of the polyglycidyl ether of polybutylene glycol.
• reaction product may be recovered from the reaction mixture, or alternatively and preferably the polyglycidyl ether of the polyaromatichydroxy compound is thereafter added to the reaction mixture and the second step of the reaction is performed.
• reaction product of the first step preferably corresponds to Formula 15:
• the reaction product of the first step is contacted with a polyglicyidyl ether of a polyaromatichydroxy compound, and additional polyaromatichydroxy compound and/or chain terminator.
• the molar amount of polyglycidylether of a polyaromatichydroxy compound is present in a ratio of greater than 1.0 as compared to the moles of the above-mentioned reaction product of the first step and more preferably 1.5 moles or greater.
• the mixture is heated until exotherm occurs.
• catalyst for the advancement of epoxy resins may be present.
• a sufficient amount of catalyst may be introduced in step 1 , such that no further catalyst need to be added in the second step.
• the reactants in the second step may be reacted neat or in the presence of a solvent.
• Solvents which may be used are those which are typically used as solvents for epoxy advancement reactions.
• a reaction in solvent may be advantageous wherein heat control is desired.
• the advancement reaction is preferably performed at a temperature of 130°C or above, as below 130° the reaction time is too slow.
• the reaction is performed at a temperature of 230°C is, the polymer reacts to fast above such temperature and unwanted colors may be formed ⁇ _. to the presence of oxidated byproducts. More preferably the reaction temperature is 180°C or below.
• the temperature which may be used for the reaction depends on whether or not a solvent is used, and its nature.
• the reaction mixture is preferably heated at a rate such that the temperature increases from 1 to 2°C per minute until exotherm is achieved. Thereafter elevated temperatures are maintained until the desired molecular weight and epoxy equivalent weights are reached.
• the Dolyepoxide advancement reaction is allowed to proceed for a time sufficient to result in substantially complete reaction, preferably 15 minutes or greater, more preferably 30 minutes or greater. Preferably the maximum reaction time is 10 hours or less and more preferably 2 hours or less.
• the flexibilized advanced epoxy resins of this invention can thereafter be recovered and formulated for use in various coatings applications
• the flexibilized advanced epoxy resins of the invention may be recovered in a semi-solid or solid state by means well known in the art
• the coating compositions which can incorporate the flexibilized epoxy resins of this invention include powder coating compositions, food and beverage can coating compositions and ambient cure coatings useful in industrial maintenance applications.
• the resin may be recovered and then converted to a form useful for such coatings
• the flexibilized advanced epoxy resins of this invention are converted to cationic resins *or use in cathodic electrodeposition coatings by rea ⁇ mg at least some of the glycidylether moieties of the resin with a nucleophilic compound and adding an organic acid and water at some point during the preparation It is also possible to rea at least some of the glycidyl ether moieties with a nucleophile salt formed by prerea ⁇ mg the nucleophile with the organic acid
• Substantially any organic acid, especially a carboxylic acid, can be used in the conversion rea ⁇ ion to form onium salts so long as the acid is sufficiently strong to promote the reaction between the nucleophilic compound and the glycidyl ether moieties of the resin
• the acid should be sufficiently strong to protonate the resultant tertiary amine produ ⁇ to the extent desired
• Monobasic acids are normally preferred (H +A-)
• Preferable organic acids include, for example, alkanoic acids having from 1 to 4 carbon atoms (e g , acetic acid, propionic acid, etc ), alkenoic acids having up to 5 carbon atoms (e g , acrylic acid, methacrylic acid, etc) hydroxy-fun ⁇ ional carboxylic acids (e g , glycolic acid, la ⁇ ic acid, etc ) and organic sulfonic acids (e g , methanes
• the conversion rea ⁇ ion to form cationic resins is normally condu ⁇ ed by blending the rea ⁇ ants together
• Goo ⁇ results can be acnieved by using substantially stoichiomet ⁇ c amounts of rea ⁇ ants although a slight excess or defioency of the epoxy- containing resin or the nucleophilic compounds can oe usec Witn weak acids
• useful ratios of the reactants range from 0.5 to 1.0 equivalent of nucleophilic compounds per glycidyl ether moiety of the resin and for organic acids from 0.5 to 1.1 equivalents of organic acid per glycidyl ether moiety.
• the amount of water present can be varied so long as there is sufficient acid and water present to stabilize the cationic salt formed during the course of the reaction, preferably water is present in amounts of from 5 to 30 moles per epoxy equivalent. It is advantageous to include minor amounts of organic solvents in the reaction mixture, the presence of which facilitates contact of the reactants and promotes the reaction rate.
• One preferred class solvents are the monoalkyi ethers of the C 2- alkylene glycois, which includes the monomethyl ether of ethylene glycol, the monobutyl ether of ethylene glycol, etc.
• any excess nucleophilic compound can be removed by standard methods, e.g., dialysis, vacuum stripping and steam distillation.
• the cationic, advanced epoxy resins of this invention in the form of aqueous dispersions are useful as coating compositions, especially when applied by electrodeposition.
• the coating compositions containing the cationic resins of this invention as the sole resinous component could be used but it is preferred to include crosslinking agents in the coating composition, so that the coated films, when cured at elevated temperatures, will be crosslinked and exhibit improved film properties.
• crosslinking agents are those known to react with hydroxyl groups or amino protons; and include blocked polyisocyanates; amine-aldehyde resins such as melamine-formaldehyde, urea-formaldehyde, benzogucinine- formaledyde, and their alkylated analogs; polyester resins, and phenol-aldehyde resins.
• Preferred crosslinking agents are the blocked polyisocyanates which, at elevated temperatures, deblock and form isocyanate groups which react with the hydroxyl groups of the resin to crosslink the coating. Such crosslinkers are ⁇ repared by reaction ofthe polyisocyanate with a monofunctional active-hydrogen compound.
• polyisocyanates and isocyanate- functional prepolymers derived from polyisocyanates and polyois using excess isocyanate groups suitable for preparation of the crossiinking agent are described in US Patent 3,959, 106 to Bosso, etal., ⁇ n Column 15, lines 1-57.
• the blocked polyisocyanate crosslinking agents are incorporated into the coating composition at levels corresponding to from 0.2 to 2.0 blocked isocyanate groups per hyoroxyl group of the cationic resin.
• the preferred level is from 0.5 to 1.0 blocked isocyanate group per resin hydroxyl group.
• a catalyst optionally may be included in the coating composition to provide faster or more complete curing of the coating. Preferable catalysts for the various classes of crosslinking agents are known to those skilled in the art.
• catalysts include dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl ti n oxide, stannous o ⁇ anoate, and other urethane- forming catalysts known in the art.
• the catalyst is used in amounts from 0.1 to 3 weight percent of binder solids.
• Unpigmented coating compositions are prepared by blending the cationic resinous product with the crosslinking agent and optionally any additives such as catalysts, solvents, surfa ⁇ ants, flow modifiers, and defoamers. This mixture is then dispersed in water by any of the known methods.
• the solids content of the aqueous dispersion is usually from 5 to 30 percent by weight, and preferably from 10 to 25 percent by weight for application by ele ⁇ rodeposition.
• Pigmented coating compositions are prepared by adding a concentrated dispersion of pigments and extenders to the unpigmented coating compositions. This pigment dispersion is prepared by grinding the pigments together with a suitable pigment grinding vehicle in a suitable mill as known in the art. Pigments and extenders known in the art are useful in these coatings, and include pigments which increase the corrosion resistance of the coatings. Examples of useful pigments or extenders include titanium dioxide, talc, clay, lead oxide, lead silicates, lead chromates, carbon black, strontium chromate, and barium sulfate.
• the pH and/or conductivity of the coating compositions may be adjusted to desired levels by the addition of compatible acids, bases, and/or electrolytes known in the art.
• Other additives such as solvents, surfa ⁇ ants, defoamers, anti-oxidants, ba ⁇ ericides, etc. may also be added to modify or optimize properties of the compositions or the coating in accordance with practices known to those skilled in the art.
• the coating compositions of the invention may be applied by cathodic ele ⁇ rodeposition, wherein the article to be coated is immersed in the coating composition as the cathode, with a suitable anode in conta ⁇ with the coating composition.
• a film of the coating deposits on the cathode and adheres to the article to be coated.
• Voltage applied is preferably from 10 to 1 ,000 volts, more preferably from 50 to 500 volts.
• the film thickness achieved increases with increasing voltage. Thicker films are achieved by incorporation of the diglycidyl ether of poiyputyiene giycol into the Dackbone of the cationic resins of the invention.
• Control over the final thickness may be excercised by adjusting the amount of that component used
• the voltage is applied for between a few seconds to several minutes, preferably from two minutes over which time the current usually decreases as a resistive film is deposited.
• Any electrically conductive substrate may be coated in this fashion, especially metals such as steel and aluminium.
• Other aspects of the electrodeposition process are conventional.
• the article is removed from the bath and rinsed with water to remove that coating composition which does not adhere.
• the uncured coating on the article is cured by heating at elevated temperatures, preferably ranging from 100° to 200°C, for periods of preferably from 1 to 60 minutes.
• the flexibilized advanced epoxy resins may be flaked or ground according to known processes and combined with epoxy curing agents and exposed to conditions such that continuous films are formed, without conversion to cationic species. Processes for preparing such powder coatings are generally well known to those skilled in the art.
• the flexibilized advanced epoxy resins of this invention can be used in solvent coatings.
• the flexibilized advanced epoxy resins and a curing agent can be dissolved in a solvent and such mixture can be coated onto a substrate and exposed to curing conditions.
• Preferred solvents are alkyl substituted benzenes, ketones, lower alkanols, glycol ethers, chlorinated alkanes, and dimethyl formamide.
• the preferred sol ids level is from 25 to 80 % by weight; and preferably from 30 to 60 % by weight.
• curing conditions comprise exposing the coated substituted to temperatures from 20 to 250°C under conditions such that the solvents can be removed from the coating.
• the flexibilized advanced epoxy resins of this invention are cured with known curing agents for epoxy resins.
• the flexiblized epoxy resin compositions are contacted with curing agents and the mixture is applied in a known manner to a substrate such that the flexibilized advanced epoxy resins are cured to form coatings.
• Curing agents useful in this invention are those compounds known to the skilled artisan to react with polyepoxides or advanced epoxy resins to form hardened final products and which function to cure the epoxy resin.
• the polyhydroxy compounds described hereinbefore wherein the hydroxy moieties are bound to aromatic moieties are among suitable curing agents.
• the novolac based compounds and the bisphenolic compounds are the preferred polyhydroxy compounds for use as curing agents.
• other preferable curing agents include the oolybasic acids and their anhydrides; othertypes of acids containing sulfur, nitrogen, onospnorus or halogens; soluble adducts of amines and polyepoxides and their salts, such as described in US 2,651 ,589 and US 2,640,037; acetone soluble reaction products of polyamines and monoepoxides; the acetone soluble reaction products of poiyamines with unsaturated nitriies; imidazolme compounds obtained by rea ⁇ mg monocarboyxlic acids with polyamines, sulfur and/or phosphorus-containing polyamines obtained by rea ⁇ mg a mercaptan or phosphine containing a ⁇ ive hydrogen
• Preferred classes of curing agents are the polyamines and amides
• Such preferred curing agents include aliphatic polyamines, polyglycoldiamines, polyoxypropylene diamines, polyoxypropylenet ⁇ amines, amidoamines, imidazolines, rea ⁇ ive polyamides, ketimines, araliphatic polyamines (i e xylylenediamine), cycloaliphatic amines (i e isphoronediamine or diaminocyclohexane) menthane diamine, 3,3-d ⁇ methyl-4,4-d ⁇ am ⁇ no-d ⁇ cyclohexylmethane, heterocyclic amines (aminoethyl piperazine), aromatic polyamines, (methylene diani ne), diamino diphenyl sulfone, mannich base, phenalkamine, N,N'N"-t ⁇ s(6-am ⁇ nohexyl) melamine,
• the flexibilized advanced epoxy resin compositions of this invention are conta ⁇ ed with sufficient curing agents to cure the resin
• the ratio of epoxy (glycidyl ether) equivalents to equivalents of curing agent is from 0 5 1 to 2 1 , more preferably from 0 6 1 4to 1 4 0 6; even more preferably from 0 8 1 2 to 1 2 0 8 and most preferably from 0 9 1 1 to 1 1 0 9
• the coatings of this invention demonstrate excellent adhesion resistance to cathodic disoondment excellent flexibility and impact resistance, good compatibility with a wide variety of resinous p inders sucn as acrylics, aikyds, polyesters as well as curing agents like polyamines, melamine or onenol resins
• resinous p inders sucn as acrylics, aikyds, polyesters as well as curing agents like polyamines, melamine or onenol resins
• EXAMPLE 1 Reaction of polypropylene glycol diglycidyl ether, bisphenol A and diglycidyl ether of bisphenol A.
• the solid resin is converted into a water-dispersed form usable for the formulation of cathodic ele ⁇ rodeposition primers by following procedure.
• the rea ⁇ or is cooled to keep the reaction temperature from rising over 1 10°C. A temperature of 110°C is maintained for 60 minutes Then 38 3 g of Dowanol* PPh glycol ether is added to the reactor A second reactor is now prepared containing a mixture of a 1306 g of deionized water, 39.3 g of lactic acid (0.31 eq. of acid) as well as 17.2 g of a mixture of suitable cationic surfactant and defoamer Under strong stirring the hot resin mixture is slowly
• the dispersion is diluted further by the addition of 637 0 g of deionized water.
• the dispersion is heated to 65°C, after which the volatile organic solvents are stripped off over 2 hours by distillation at a reduced pressure of 250 mbar.
• the solids content of the dispersion, after 1 hour drying at 150°C, is determined to be 36 40 %
• the dispersion is mixed with a commercially available
• Example 2 To a reactor similar to the one described in Example 1 is charged 618 1 g of the diglycidyl ether of polypropylene glycol described in Example 1 and 831 6 g of bisphenol A (7 24 eq of phenolic hydroxyl) The mixture is heated to 100°C and 2 9 g of ⁇ ⁇ alkyltriphenylphosphonium catalyst is added The rea ⁇ or is slowly heated to 150°C (1 to 2°C per minute).
• Example 2 is repeated using 620.0 g of the diglycidyl ether of polypropylene glycol (EEW 317.7) prepared from a polypropylene glycol of MW 390, 571.0 g of bisphenol A and 2.9 g of alkyltriphenylphosphonium catalyst. The mixture is heated to 100°C. The reactor is then slowly heated to 150°C (1 to 2°C per minute).Tothe reaction mixture is added 1543.8 g of ⁇ the diglycidyl ether of bisphenol A described in Example 1 (8.33 epoxy equivalents). The temperature drops to 110°C as a result of this addition. The mixture is mixed for 5 minutes and then the temperature is slowly raised by heating (1 to 2°C per minute).
• Example 3 is repeated with 412.2 g of a diglycidyl ether of a polybutylene glycol
• Example 3 is repeated with 412.2 g of a diglycidyl ether of a polybutylene glycol (EEW 367.0), wherein the MW (number average) of the polybutylene glycol precursor is 550; 546.5 g of bisphenol A, and 2.0 g of catalyst as described in Example 1. It takes about 60 minutes until the weight percentage of epoxy in the mixture is less than 0.1. To the rea ⁇ or is added 1042.2 g of the liquid epoxy resin described in Example 1. The EEW of the resulting resin is 1087. An aqueous dispersion is prepared as described in Examples 1 and 2.
• EXAMPLES 2 to 5 Cathodic Deposition of Coatings and Testing of Properties Dispersions prepared in Examples 2 to 5 are separately deposited on Bonder 26 phosphatized steel panels by electrodeposition, rinsed in deionized water and baked at 175°C or 20 minutes. Deposition conditions are chosen such that the coating has a thickness of 25 microns. The Erichsen Indentation test is performed to a "first crack" endooint. The Salt Bath corrosion test conditions are 500 hours of immersion in a 5 percent so ⁇ ium chloride in water solution at 55°C The results are compiled in Table !l. Table II
• the resulting resin is converted into an aqueous dispersion using the procedure described in Example 1 , with the exceptions that the crosslinker is as described in US Patent 4,104,147, more particularly 70 wt % solution in MIBK of an 3: 1 :3 adduct (based on molar .... quantities) of toluenediisocyanate, t ⁇ methylolpropane and ethylhexanol. Additionally, 10 g of dibutyltindilaurate curing catalyst is added to the resin crosslinker blend, just before dispersing it into water.
• the dispersion is diluted to 20 wt % solids and used for ,_ eie ⁇ rodepositing an unpigmented coating unto Bonder 26 panels and unto degreased untreated steel panels.
• the coatings are cured for 20 minutes at 190°C. Deposition conditions are cnosen in such a way that the final film thickness of the cured films is 20 urn.
• EXAMPLE 7 Rea ⁇ ion of Bisphenol A with diglycidyl ether of polypropylene glycol, and subsequent rea ⁇ ion with Bisphenol A diglycidyl ether Not an example of the invention
• EXAMPLE 9 Rea ⁇ io ⁇ of Bisphenol A with diglycidyl ether of polybutylene glycol and suosequent rea ⁇ ion with diglycidyl ether of Bisphenol A 5
• 389.2 g of D.E.R.* 331 epoxy resin is added.
• the resulting resin has an EEW of 1054. Conversion into an aqueous dispersion, electrodeposition and curing are performed in the same way as described in Example 6, except for the amount of neutralizing acid which is 5 % higher.
• the flexibility of the coating istested by bending the coated panels around an 18 mm diameter mandrel in accordance with DIN 35571 flexibility test. 10 panels prepared as described and at an average coating thickness of 347 microns are found to tolerate a 36.5 degree flex before cracking. This is considered to be excellent flexibility.
• EXAMPLE 12 Reaction of digiycidyl ether of polybutylene glycol with bisphenol A and subsequent reaction ofthe product with diglycidyl ether of bisphenol A.
• EEW is found to exceed 2800.
• the advanced resin is poured from the reactor into an aluminum foil tray and allowed to cool to room temperature.
• the Metier Softening Point is determined to be 104.1°C and the solution viscosity at 40 wt % solids in diethylene glycol monobutyl ether is measured to be 1914 cSt. 30
• the formulation is applied using a wire wrapped draw down rod to a 0.235 mm thick sheets of Ancrolyt tin free steel and Androlyt tm plate (both available from Rasselstein AG) which have been degreased by rinsing with acetone.
• a wet application of between 20 to 40 microns is chosen such that dry film thickness of 5 to 6 microns is obtained.
• the coated tin ⁇ plate panels are placed in a circulating air oven preheated to 200°C for a cure time of 10 minutes.
• the coated tin free steel panels are cure at 280 for 28 seconds.

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• 1992
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