US 3779991 A
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United States Patent O US. Cl. 260-465 E 13 Claims ABSTRACT OF THE DISCLOSURE Resin composition comprising the reaction product of a reactive hydantoin based compound, a polycarboxylic acid, and tris (2-hydroxyethyl) isocyanurate. The resin provides a low cost, cured enamel for electrical conductors characterized by high thermal stability and a low coefficient of friction when it contains linear, reactive organo silicon material.
CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of my co-pending application, Ser. No. 58,173, filed July 24, 1970, issued as US. Pat. 3,681,282 the teachings of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION This invention relates to novel polymeric materials containing hydantoin radicals and silicon radicals in the polymeric backbone.
There has been a continuing demand for improved magnet wire enamel coating which possesses good electrical insulating properties, resistance to heat and solvent attacks, and other desirable properties. U.S. Pats. 3,211,585 and 3,342,780 disclose examples of such an enamel for magnet conductors when these properties are obtained by utilizing the reaction product of a polycarboxylic acid and tris (Z-hydroxyethyl) isocyanurate (THEIC).
Magnet wires having such insulating enamel coatings are used in winding electrical coils for use in relays, solenoids and the like. Such magnet wires are coated by passing the wire through a solution of the polymer, and the resultant coating is dried and/or hardened by passing through a drying oven. The dried and coated wire is then wound at high speeds into coils. During the high speed winding process, it has been customary heretofore to apply a lubricating oil to the coated wire in order to reduce friction and, after the coil has been wound, varnish the entire assembly by dipping in varnish. However, the varnish will not adhere well to the wire which has been previously oiled, and it has been necessary to degrease the wound bobbins before varnishing.
Aside from the necessary steps of applying oil to the wire and then degreasing the wound bobbins, the use of oil in winding the wire into bobbins has other disadvantages. Dust and dirt tend to collect on winding equipment and wires coated with oil. Further, the oil is a fire hazard since it may be heated by friction developed during winding or from the machinery and ignite.
There is, therefore, a demand for enamel coated magnet wire which has a low coefficient of friction so that the use of lubricating oil in the winding process is rendered unnecessary. However, such a low friction enamel wire must also possess good electrical insulating properties, resistance to the relatively high temperature encountered by electrical equipment, and other properties demanded of the nonself-lubricating enamel. One such magnet wire coating is disclosed in my application, Ser. No. 854,285, filed Aug. 29, 1969, for Sil-Alkyd Coatings for Wire, now Pat. No. 3,583,885.
3,779,991 Patented Dec. 18, 1973 "ice Further, the THEIC based resins used for high temperature applications have a high cost and are often prohibitively expensive. Thus, less expensive substitutes and partial substitutes for THEIC are desirable.
Accordingly, it is an object of the present invention to provide a novel enamel coating for magnet Wires less expensive than the THEIC based resins but having equivalent, if not better, properties in comparison to THEIC resins.
It is a further object of this invention to provide a resin characterized by a low coefficient of friction. These low friction coatings do not require the use of oil in their winding, and are compatible with varnish in which wound coils 'are dipped to improve the insulation thereof. They also possess excellent electrical properties and exceptionally good resistance to heat aging.
Further objects of the invention will become apparent to those skilled in the art from a reading of the following description.
SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a new magnet wire coating which comprises a polymer containing both hydantoin rings and silicon groups in the backbone. Silicon groups can be eliminated from the polymer where a low coefficient of friction is not needed.
The preferred novel polymers of the present invention have hydantoin and organo-silicon radicals in the resin backbone and are the reaction product of hydantoin based compound having reactive OH, H, -COOH, alkoxy, and NH groups and equivalents thereof; a carboxylic acid having at least two carboxy groups or an anhydride, ester, chloride of said acid: THEIC, and, when dry lubricity is desired, a linear reactive organo silicon material having reactive OH, H, COOH, alkoxy, amino, aryloxy or vinyl groups. A preferred silicon material is a silane diol such as diphenyl silane diol. In a more limited embodiment, up to 50 equivalent percent of the THEIC is replaced by another polyhydric alcohol such as ethylene glycol.
Thus, the novel polymers of the invention may be prepared by reacting THEIC, the carboxylic acid, and the reactive-hydantoin based compound. When dry lubricity is desired, the reaction includes the reactive silicon-containing material. These reactions are affected by means known to the art. Preferred are reaction temperatures of about C. to about 250 C. and reaction time of about 4 hours to 24 hours.
DESCRIPTION OF THE PREFERRED EMBODIMENTS As indicated, the novel polymers of the present invention are obtained by reacting a hydantoin-containing compound, a carboxylic acid and THEIC and, when dry lubricity is required, a reactive silicon-containing compound. As the reactive silicon-containing material, a silane or a siloxane may be used preferably in an amount of about 0.01 to about 10% by weight of the total composition. As is known in the art, a monomeric silane, such as dichlorodimethyl silane, will react with moisture to form polymeric siloxanes with repeating units therein. The silanes and siloxanes suitable for the purposes of the present invention are disclosed in my Pat. No. 3,583,885, filed Aug. 29, 1969, for Sil-Alkyd Coatings for Wire, the disclosure of which is hereby incorporated by reference. It will be appreciated that the silanes and siloxanes which are suitable for use in the present invention are.
generally those having hydrogen, alkyl or aryl radicals attached to the silicon atom and that, if the siloxane is a polymeric material, it is a linear chain (two dimensional) rather than one in three dimensional configuration. Resinous polysiloxanes, having three dimensional structural formulas, are not satisfactory for the purpose of the invention because they do not possess the proper lubricity.
Chlorosilanes, alkylated siloxanes, oxygenated siloxanes, hydroxy siloxanes and amine siloxanes and the like having reactive radicals, react directly with the hydantoin to form hydantoins with pendant groups along the hydantoin chain. I prefer to use organo-siloxanes having two or three reactive --OH, --H, -COOH, vinyl or alkoxy groups. For example, the -OH, alkoxy and H react with an acid component, while the -COOH groups react with a polyol component of the polyester.
The preferred siloxanes have the following formula l. Ll. ll.
wherein R is CH or phenyl, R is CH phenyl, OH, H, amino carboxy, alkyl, or methyl alkyl, and n=2 to 20 or more; or a siloxane of the general formula RmSiXnO (m R is an alkyl radical of less than 5 carbon atoms or a phenyl radical, X is an alkoxy, arylcxy or H radical, m has an average value from 1 to 2, n has an average value of from .01 to 3, and the sum of (m+n) is not greater than 4. The above organosilicon compounds include both monomeric alkoxy-silanes and silanols of the formula R SiX and partial condensates thereof.
These partial condensates are polymeric siloxanes having hydrocarbon groups, alkoxy groups and/or OH radicals attached to the silicon. The number of functional (i.e. X) groups per silicon may vary from 1 functional group per 100 silicons to 3 functional groups per silicon. Both the above silanes and the partial condensates are known materials.
The hydrocarbon groups may be alkyl radicals such as methyl, ethyl, propyl, butyl, or phenyl radicals. Any alkoxy groups may be present in the silanes although it is preferred that the alkoxy radicals contain less than 5 carbon atoms, since the corresponding alcohols are more easily removed from reaction mixtures.
Specific silanes which may be employed in this invention are, for example, phenylmethyldiethoxysilane, phenyltrimethoxysilane, dimethyldiisopropoxysilane, diethyldibutoxysilane, monomethyltriisopropoxysilane, diphenylsilanediol, phenylmethylsilanediol and diethylsilanediol. It is understood that either individual silanes or mixtures of one or more silanes may be employed together with partial condensates of individual silanes or mixed silanes.
Other suitable siloxanes include 1,3 bis(4-arninobutyl) 1,l,3,3', tetramethyl disiloxane, carbethoxymethyl tetramethyl disiloxane, hexamethyldisilazane, dimethyl polysiloxane, gamma aminopropyltriethoxy silane, vinyltrichlorosilane and hexamethyldisilazane.
The preferred hydantoin compounds are monomeric reactive hydantoin compounds represented by the formula:
wherein A is H, OH, ROH, COOH, -NH or (OR) OH wherein R is (CH and y is 1 5, x is an integer in the range of 1 to and B is H or a C C alkyl group.
Typical hydantoin monomers are diphenyl hydantoin, dimethyl hydantoin, diethyl hydantoin, mono methylol dimethyl hydantoin, (dimethyl hydantoin methyl) amine, methylene bis dimethyl hydantoin, and dihydroxydiethyl 5,5 dimethyl hydantoin. The reactive hydantoin compound can be prepared, in an alternative embodiment, by reacting HCN and a diisocyanate, reacting N-phenyl glycine esters with phenylisocyanate or by reacting a glycine with a polyisocyanate, a polyisothiocyanate or a polyamine.
While monomers are preferred, it is within the scope of this invention to utilize dimers and trimers of these monomers. Preferably the hydantoin comprises about 5% to about 50% by weight of the composition and afl'ects a partial substitution for THEIC without adversely affecting the properties of the resin. Preferably, the THEIC comprises about 5% to about 50% by weight of the composition.
The last method indicated for making a reactive hydantoin-containing component herein and the glycine derivatives which are suitable are disclosedin the Merten et al. US. 3,397,253. It may be stated generally such glycine derivatives are prepared by the reaction of an aromatic polyamine with a haloacetic acid. Representative examples of such glycine derivatives are: N,N'-bis-carbethoxymethyl-4-4' diamino diphenyl methane; N,N-biscarbethoxymethyl-4-4' diamino diphenyl ether.
Preferred glycine derivatives for this process are compounds of the general formula:
wherein Ar represents an aromatic radical, Z represents hydrogen or COR R represents hydrogen or alkyl, R represents the hydroxyl group or an amino group, an alkylamino-, dialkylamino-, alkoxy-, or aroxy group and x is an integer between 2 and 4. R represents a dialkylamino group, an alkoxy group or an aroxy group. The glycine derivatives used according to the invention should contain the radical tri at least twice in the molecule.
The aromatic radical Ar is preferably a radical derived from benzene, azobenzene, naphthalene, anthracene, diphenyl, triphenylmethane, a diphenylalkane, a diphenylalkene, diphenylether, diphenylthioether or a polyphenylether. These radicals may also be substituted once or several times, for example, by alkyl- (methyl-) halogen (chloro-), nitro-, alkoxy- (methoxy-), dialkylamino- (dimethylamino-), acyl- (acetyl-), carbalkoxy- (carbomethoxy or -ethoxy) and cyano groups. Benzene-, naphtha1ene-, diphenylmethaneand diphenylether derivatives which may be substitued once or twice by methyl groups and/ or chlorine atoms are preferred.
The preparation of the glycine derivatives used as starting materials according to the invention is known and may, for example, be carried out by direct reaction of aromatic polyamines with haloacetic acids or derivatives thereof or by condensation with hydrocyanic acid and aldehydes or ketones, followed by conversion of the nitrile group into, for example, carboxylic acid, ester or amide.
The reaction of aromatic polyamines with haloacetic acid or its derivatives is carried out in an organic solvent, e.g. in ethanol, methanol, acetone, benzene or in an aqueous medium with the use of acid bindin agents such as tertiary amines (e.g. pyridine, triethylamine), excess starting amine, soda, potash, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, calcium oxide or calcium carbonate.
Suitable haloacetic acids or derivatives thereof are, for example, chloroacetic acid, chloroacetamide, N,N-dialkylchloroacetamide (alkyl being preferably methyl, ethyl, butyl), chloroacetic acid esters (e.g. methyl, ethyl, phenyl esters), a-chloropropionic acid esters and a-chloropropicnic acid.
Another method consists in condensing aryl polyamines with cyanides (e.g. NaCN, KCN) and x0 compounds (e.g. formaldehyde, acetone, acetophenone) with addition of acids; the nitriles obtained can then be saponified in known manner to form carboxylic acids or converted directly into esters by means of alcoholic hydrochloric acid. Other processes consist in modifying glycine derivatives already prepared, e.g. by esterification of the free acids or aminolysis of the esters.
Suitable aromatic polyamines for use in the invention are compounds having at least two amino groups bound to aromatic nuclei although these must not be arranged in the oor peri-position. Furthermore, the amines may be substituted in any way desired. Examples of such aromatie polyamines are the following:
mand p-phenylene diamine, 2,4-, 2,5- and 2,6-toluylene diamine, diisopropylbenzene diamines, 1,3,5-triaminobenzene, 2,4,6-triaminotoluene, 4,4-diaminoazobenzene, 2,4,6-triaminoethylbenzene, 1,3,S-triisopropylbenzene-diamines, 2-chloro-l,4-phcnylene diamine, 2,5-dichloro-1,4-phenylene diamine, 2,6-dichloro-1,4-phenylene diamine, 2,6-diaminoand 4,6-diamino-5-methyl-1,3-diethylbenzene, 1,3-, 1,4-, 1,5-, 1,6-, 1,7-, 2,4-, 2,5-, 2,7- and 2,8-diaminonaphthalene, 14-diaminoanthraquinone 1,S-diaminoanthraquinone, 4,4'- and 2,4-diamino-diphenyl ether, 4,4'- and 2,4'-diamino-diphenylthioether, 4,4-diamino-diphenyldisulfide, 4,4-diamino-diphenyl, 4,4'-diamino-3,3'- or -2,2'-dichlorophenyl, 4,4'-diamino3,3'-dialkoxy-diphenyl, 4,4'-diamino-3,3'-dimethyl-diphenyl, 4,4-diamino-diphenylmethane, 2,2-bis-p-aminophenyl-propane, 1,2-bis-p-aminophenyl-ethane, 4,4-diamino-stilbene, 4,4-diamino-azobenzene, 4,4-diamino-diphenylsulfon, 4,4',4"-triamino-triphenylmethane, diamino-carbazole, 2,2"-dichloro-4,4"-diaminotriphenylether, and 2,4-diamino-6-phenyl- 1,3,5 )-triazine.
High molecular weight compounds containing several aromatically bound amino groups e.g. aniline formaldehyde resins, may also be used.
Suitable polyisocyanates and polyisothiocyanates to be heated with the glycine derivatives are, for example, aliphatic, cyclophatic or aromatic compounds having at least two NCO- or NCS groups in the molecule. The following are examples of such polyisocyanates: Polymethylene diisocyanates of the formula wherein n1s a number from 4 to 8, benzene diisocyanates which may be substituted with alkyl groups, for example mand p-phenylene diisocyanates, toluylene-2,4- and -2,6- diisocyanate, ethylbenzene-diisocyanates, diand tri-isopropyl benzene diisocyanates, chloro-p-phenylene diisocyanates, diphenylmethane diisocyanates, naphthalene diisocyanates, ester isocyanates such as triisocyanato-arylphosphoric ester and -thioester, glycol-di-p-isocyanatophenyl ester, 4,4 diisocyanato-diphenylether, 1,2-bis-pisocyanato-phenylethane and 4,4 diisocyanato-stilbene. Partially polymerised isocyanates having isocyanurate rings and free NCO groups may also be used.
The polyisocyanates may also be used in the form of their derivatives, e.g. the reaction products with phenols,
alcohols, amines, ammonia, bisulphite, HCl etc. Individual examples of these are phenol, cresols, xylenol, ethanol, methanol, propanol, isopropanol, ammonia, methylamine, ethanolamine, dimethylamine, aniline and diphenylamine. Relatively high molecular weight addition products, e.g. of polyisocyanates with poly-alcohols such as ethylene glycol propylene glycol, trimethylolalkanes or glycerol may also be used.
Instead of the polyisocyanates mentioned, the corresponding thio compounds may be used as Well.
The process is generally carried out by heating the two starting components for some time in an organic solvent, the polymer produced remaining in solution. The polymer can be isolated by distilling olf the solvent. The quantities of starting compounds may be so chosen that 0.5 to 10 mols of isocyanate or isothiocyanate groups are available per mol of NH group, and it is preferable to use 1 to 3 mols of isocyanate or isothiocyanate. Suitable solvents for the process are compounds which are inert to NCO groups, e.g. aromatic hydrocarbons, chlorinated aromatic hydrocarbons, aliphatic hydrocarbons, esters and kctones.
Especially suitable are N-alkylpyrrolidones, dimethylsulphoxide, phenol, cresol and dimethylformamide. Where iso (thio) cyanate derivatives are used, other solvents, such as alcohols or phenols, may also be used. On the other hand, it is also possible to react the components together directly without the use of solvent.
The reaction times vary between 30 minutes and several days and may in special cases lie above or below these limits. The reaction temperatures are chosen to be between 0 and 500 C., depending on the starting material.
It is preferred to work at 20 to 350 C., the best results being obtained in the region of 20 to 230 C.
The condensation reactions may be accelerated by the use of catalysts, e.g. metal alcoholates or tertiary amines.
In the polymerisation according to the invention there takes place, in addition to the condensation of the two reactants, a ring closure reaction to form the hydantoin ring, as can be represented by the following reaction equation:
The preferred hydantoin polymers used in this invention contain the recurring unit wherein Ar corresponds to the definition already given, R represents hydrogen and alkyl having 1 to 6 carbon atoms and y is Ar and additionally alkyl having 4 to 10 carbon atoms (one or more of which may be replaced wherein Ar stands for an aromatic radical, R is hydrogen or alkyl, R is H, an amino group, an alkylamino group, a dialkylamino group, an alkoxy group or an aroxy group, R represents a dialkylamino group, an alkoxy group or an aroxy group and x is an integer between 2 and 4.
Thus, the glycine derivatives to be used according to the invention should contain the radical at least twice in the molecule.
The aromatic radicals Ar are preferably the radicals derived from benzene, azobenzene, naphthalene, anthracene, triphenylmethane, diphenylmethane or diphenylether. These radicals may carry one or several substituents for example alkyl- (methyl-), halogen- (chloro-), nitro-, alkoxy- (meth'oxy-), dialkylamino- (dimethylamino-), acyl- (acetyl-), carbalkoxy (carbomethoxyor carboethoxy-) and cyano groups. It is advantageous to use the benzene, naphthalene, diphenylmethane or diphenylether derivatives which may be substituted, once or twice, by methyl and/or chloro functions. The glycine derivatives to be used according to the invention as starting materials prepared according to known methods. By the direct reaction of the corresponding aromatic polyamines with hydrocyanic acid and aldehydes or ketones and subsequent conversion of the nitrile group into the desired carboxyl .function, for example carboxylic acid ester or amide or by condensation of the aromatic polyamines with haloacetic acid or derivatives thereof, there are obtained glycine derivatives having a free NH- function which can subsequently be converted into the desired starting materials by means of chlorocarbonic acid alkylester or chlorocarbonic acid arylester. The reaction with the halogen acetic acid or derivatives thereof as well as the chlorocarbonic acid derivatives proceeds in the sense of a Schotten-Baumann reaction, for example in an organic solvent such as ethanol, methanol, acetone or benzene, or in an aqueous medium with the simultaneous use of an acid acceptor, for example a tertiary amine (pyridine, triethylamine), excess starting amine, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide or calcium carbonate.
This procedure is essentially the same as already described.
The following condensation with chlorocarbonic acid alkylesters or chlorocarbonic acid arylesters, for example chlorocarbonic acid methyl-, -ethyl-, -propyl-, -phenylor tolylester, is carried out under substantially equal conditions. It is possible to successively combine several processing steps in one reaction step, for example, condensation reactions with chloroacetic acid derivatives and chlorocarbonic acid derivatives. Another method for the prep aration of the glycine derivatives to be used according to the invention comprises condensing the corresponding carbamic acid esters having a free NH-- group with a chloroacetic acid derivative, in general via the salt of are reacted at elevated temperature with a primary polyamine, i.e., a compound having at least two primary amino groups, yielding the polyhydantoins. The reaction can be represented for example by the following formula Suitable polyamines for the reaction with the above described glycine derivatives are for example aliphatic, cycloaliphatic and in particular aromatic compounds containing at least two primary amino groups in the molecule. As examples for these polyamines there are mentioned a,w-diaminoalkanes having two to eighteen carbon atoms in the molecule, such as ethylene diamine, propylene diamine-1,2, and -1,3, 1,4-diamino-butane, hexamethylene diamine, and octamethylene diamine, besides their alkyl substitution products and polymers, such as trimethyl-hexamethylene diamine, diethylene triamine, triethylene tetramine or dipropylene triamine, aminomethyl group-containing aromatics such as 1,3- or l,4-xylylene diamine as well as the aromatic polyamines mentioned with reference to the preparation of the glycine derivatives.
The process of the invention is generally conducted by heating the two components, preferably, in stoichiometric quantities to elevated temperature in order to effect the aminolysis represented by the above equation. This reaction is preferably carried out, at least towards the end of the reaction, in the presence of an aromatic solvent. Suitable solvents for this purpose are inert organic solvents such as aliphatics, aromatics, halogen hydrocarbons, in particular N-alkylpyrrolidones, dimethylformamide, dimethylacetamide, dimethylsulfoxide, phenol and cresols.
The condensation of the components is in general effected within the range between and 350 C., preferably between and 200 C., by preparing, first in the absence of a solvent, pre-condensation product the molecular weight of which is increased as the reaction progresses at elevated temperature. The condensation reaction can be activated by the use of an acidic, an alkaline or a metal catalyst (sodium carbonate, sodium hydroxide solution, endoethylene piperazine, triethylamine, phosphoric acid, p-toluene sulfonic acid, sodium phenolate, lead oxide or titanium tetrabutylate).
The condensation degree of the resulting polymers containing sevceral hydantoin groups in the molecule is determined by the choice of the quantitative ratio of the glycine derivative and the amino compound as well as by the reaction conditions. Polymers of high molecular weight i.e. about above several thousand can immediately be taken up in a solvent at the end of the condensation or after desired condensation degree has been achieved.
Particularly suitable are polycondensates containing hydantoin or thiohydantoin rings, which are linked through their nitrogen atoms by bivalent organic groups, such as alkylene groups containing 4 to 10 carbon atoms, phenylene groups, toluylene groups, diphenylene groups and diphenylether groups.
Although not essential, additional flexibility can be imparted to the final resin reaction product by the addition of a polyhydric alcohol in an amount up to 50 equivalent weight percent of the THEIC, and preferably in the amount of about 1% to about 10% by weight of the final product. Suitable polyhydric alcohols include both glycols and polyols.
The glycol employed can vary widely. In general, they are the glycols conventionally employed in preparing polyesters. Suitable examples include alkylene glycols of the formula H(OA) OH where n is, for example, l-10 or higher and A is alkylene, such as ethylene, propylene, butylene, etc., for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, triethylene glycol, butylene glycol, tetrameth- 9 ylene glycol, neopentyl glycol, Z-methyl-1,3-pentanediol, 1,5-pentanediol, hexamethylene glycol, xylylene glycol, etc. Preferably, one employs an alkanediol of the general formula HO(CH ),,OH where n=25 or isomers thereof wherein the alkane group is branched and/or the hydroxy groups are not terminal. The preferred glycol is ethylene 1 col.
g Ihe polyols used in the preparation of the polyesters of this invention can be widely varied and are those containing at least three esterifiable hydroxy groups. In general, these are the polyhydric alcohol conventionally employed in preparing polyesters. Illustrative examples of such alcohols are glycerol, polyglycerol, pentaerythritol, mannitol, trimethylolpropane, trimethylolethane, 1,2,6- hexanetriol, polypentaerythritol, polyallyl alcohol, polymethallyl alcohol, polyols formed by the condensation of bisphenols with epichlorohydrin, and the like.
Preferred polyhydric alcohols to be used in the preparation of these polyesters are the aliphatic alcohols possessing from 3 to 6 hydroxyl groups and containing from 3 to 14 carbon atoms, such as glycerol, pentaerythritol, mannitol, 1,4,6-octanetriol, 1,3,5-hexanetriol and 1,5,10- dodecanetriol.
A variety of monocyclic aromatic polycarboxylic acids (i.e. having at least two carboxy groups) may be used in the copolymer of the present invention. Similarly, anhydrides, chlorides and esters of these acids are suitable. Preferred are the dicarboxylic acids and anhydrides, chlorides and esters thereof having the reactive groups in either the para or meta positions.
The acid, anhydride or ester is preferably utilized in I the amount of about 5% to about 50% by weight of the final copolymer. Illustrative aromatic acids include phthalic acid, isophthalic acid, terephthalic acid, diphenic acid, hemimellitic acid, trimellitic acid, dchlorophthalic acid, etc.
Particularly preferred polycarboxylic acids are the aromatic dicarboxylic acids, containing from 6 to 10 carbon atoms wherein the two carboxyl groups are attached directly to the aromatic nucleus such as the phthalic acids, and preferably isophthalic acid, terephthalic acid mixtures of isophthalic acid and terephthalic acid and anhydrides, chlorides, and esters thereof.
In some cases it may be desirable to utilize other forms of the acids such as the acid anhydrides or acid chlorides, such as phthalic anhydride or trimellitic anhydride.
The esters of the polybasic acids may be produced by an ester-exchange reaction. Preferred derivatives to be used for this purpose comprise the esters of the abovedescribed acids and the lower saturated monohydric alcohols, preferably those alcohols containing from 1 to 5 carbon atoms, such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol and amyl alcohol.
Examples of other suitable materials include trimellitic anhydride; pyromellitic acid dianhydride; 3,3',4,4'-benzophenone tetracarboxylic dianhydride; dimethylterephthalate; dimethylisophthalate, terephthaloyl chloride; isophthaloyl chloride, and 1,1,3-trimethyl-5-carboxy-3-(pcarboxyphenyl) indan. In addition, polycarboxylic aliphatic acids such as adipic acid, maleic acid, glutaric acid, succinic acid, etc. may be used.
Preferably, when the resin composition is used as an enamel for wire, metal dried in an amount of 0.2 to 1.0% metal based on total solids is used. Typical metal driers include the zinc, lead, calcium or cadmium lineoleates, octoates and resinates of each of the metals. For example, zinc resinate, cadmium resinate, lead linoleate, calcium linoleate, zinc naphthenate, lead naphthenate, calcium naphthenate, cadmium naphthenate, zinc octoate and cadmium octoate may be used. Polyvalent metal driers such as manganese and cobalt naphthenate can also be employed. A tetraalkyl titanate can be used in small amounts, i.e. 0.001 to 4.0% by weight titanium metal of the total solids, in place of the metal dried. Typical titanates are tetraisopropyl titanate, tetrabutyl titanate,
tetrahexyl titanate, tetraoctyl titanate, tetramethyl titanate,
When used as a wire enamel, the resin is to be diluted with a suitable solvent such as cresylic acid. The individual cresols present in the acid can also be used but itis preferred to use a commercial available cresylic acid mixture. It is also frequently desirable to dilute the cresylic acid with an aromatic hydrocarbon such as coal tar, petroleum naphtha, xylene, etc.
The present invention is further described by the following examples wherein there is illustrated wire coatings having a coeflicient of friction of less than 0.20 and good heat aging properties which are less expensive than the traditional THEIC based resins.
EXAMPLE 1 To a reaction vessel equipped with a condenser, stirring rod, and gas inlet tube, the following materials were added in the proportions indicated:
Parts by weight Dimethyl terephthalate 250.0 Tris(2-hydroxy ethyl) isocyanate (THEIC) 250.0 Dihydroxydiethyl 5,5 dimethyl hydantoin 25.0 Diphenyl silanediol 3.3
The temperature was raised rapidly to C., whereupon 3.3 parts of litharge were added with 100 parts of xylene. The temperature was held at C. for 2-6 hours. Nitrogen was used as a purge to remove xylene and other small fractions. The temperature was then allowed to rise to 220-240 C. and when the viscosity reached a clear hard pill stage the mass was quenched with cresylic acid.
The above polymer was diluted using a solvent ratio of 60 parts cresylic acid and 40 parts of aromatic hydrocarbon solvent. The enamel was placed on 18 gauge copper magnet wire. The coated wire had good Class 180 C. NEMA properties and a coefficient of friction of .147.
EXAMPLE 2 Following the procedure set forth in Example 1, the following formula was prepared:
Parts by weight Dimethylterephthalate 350.0 Tris (Z-hydroxyethyl) isocyanurate (THEIC) 250.0 Dihydroxydiethyl-5,5-dimethyl hydantoin 108.0 Trimethylolpropane 16.0 Diphenylsilanediol 3.9 Litharge (as alcoholysis catalyst) 0.9 Xylene (as azeotrope) 100.0
The resulting polymer was applied to wire as a base coat and topcoated with an amide-irnide resin. The resultant wire passed all tests for NEMA Class 180 C.
EXAMPLE 3 Following the general procedure set forth in Example 1, the following formulation was prepared:
Parts by weight Ethylene glycol 8.26 1,3-dihydroxyethyl-5,5'-dimethylhydantoin 16.52 Terephthalic acid 32.57 Isophthalic acid 6.88
Tris (2-hydroxyethyl) isocyanurate (THEIC) 26.61
Diphenylsilanediol 0.60 Tetraoctyl titanate 0.20 Cresylic acid 8.26
sistance were also observed. A tabulation of the properties of the enamel is presented in Table I.
EXAMPLE 4 Following the general procedure set forth in Example 1, the following formula was prepared: I
Parts by weight Isophthalic acid 113 Terephthalic acid 529 Tris (Z-hydroxyethyl) isocyanurate (THEIC) 216 Glycerin 76 Ethylene glycol 237 Diphenyl silanediol l Tetraoctyl titanate 3 EXAMPLE 5 Following the general procedure set forth in Example 1, the following formula was prepared: v Parts by weight Isophthalic acid 113 Terephthalic acid 529 Trishydroxyethylisocyanurate 216 Glycerine 76 Ethylene glycol 159 1,3dihydroxyethyl-S,5'-dimethyl hydantoin 270 Diphenyl silanediol 9.9
Tetraoctyl titanate 1.5
The temperature of the reaction was allowed to rise to 220 C. over a period of 9 to 18 hours. The polymer was then diluted using a solvent ratio of 70 parts cresylic acid and 30 parts of aromatic hydrocarbon solvent to form a wire enamel. The enamel was then cured on AWG 18 copper wire. The properties of the enamel are tabulated in Table I. In comparison to the enamel of Example 4, an improvement in heat shock (450 C.), dielectric strength (500 volts/mil) and burnout resistance (50 seconds) were observed when compared to Example 4. Accordingly, a comparison of Examples 3 and 5 with Example 4 clearly shows the beneficial properties produced by a reactive hydantoin in a THEIC based resin. Similar results are obtained with other hydantoin based compounds having, for example, reactive-H, COOH, alkoxy, --NH groups and the like. With the exception of a higher coeflicient of friction, similar resins are produced by the elimination of the silicon compound.
EXAMPLE 6 Following the general procedure of Example 1 part of the terephthalic acid was replaced with a hydantoin acid as follows:
Parts by weight The reaction was allowed to proceed in a manner similar to previous enamels. The resultant enamel showed improvements in unilateral and emersion scrape abrasion and heat shock properties. The properties of the enamel are tabulated in Table I.
TABLE I Example 3 4 5 6 S118 1115 X; 1X 1X 1X 1X Unila tzeral abrasion" 1, 870 2, 000 1, 800 2, 000 Dielectric (volts/mil) 3, 250 2, 800 3, 306 2, 900 Heat shock C. 200 a 175 210 250 Out through 275 260 275 260 Emersion scrape (lbs.).. 32 22 23 30 Coeflicient of friction 12 14 12 14 Burnout resistance (sec.) 500 417 467 450 l Fail.
What is claimed is:
1. A resin composition having hydantoin and organosilicon radicals in the resin backbone which comprises the reaction product of:
(a) a reactive, monomeric hydantoin or polymeric hydantoin compound having reactive OH, H, COOH, alkoxy and NH groups;
(b) an aromatic carboxylic acid having at least two carboxy groups or an anhydride, ester, or chloride of said acid;
(0) tris (Z-hydroxyethyl) isocyanurate, as a polyhydric alcohol component; and
(d) a linear reactive organo-silicon silane or siloxane having reactive OH, H, COOH, alkoxy, amino, aryloxy or vinyl groups,
(c) said reaction elfected at a temperature of about C. to about 250 C.
2. A resin composition according to claim 1 wherein up to 50 equivalent percent of the isocyanurate is replaced by another polyhydric alcohol.
3. A resin composition according to claim 2 wherein said alcohol is ethylene glycol.
4. A resin composition according to claim 1 wherein said carboxylic acid is terephthalic acid, isophthalic acid, a mixture of terephthalic acid and isophthalic acid, or an anhydride, ester or chloride of said acid.
5. A resin composition according to claim 1 wherein said hydantoin is 1,3dihydroxyethyl-S,5'-dimethyl hydantoin.
6. A resin composition according to claim 1 wherein said silicon material is diphenyl silane diol.
7. A resin composition according to claim 1 wherein said reaction product comprises 5-50% by weight of said hydantoin 550% by weight of terephthalic acid, isophthalic acid, a mixture of terephthalic acid or isophthalic acid, or an anhydride ester or chloride of said acid, 5- 50% by weight tris (2-hydroxyethyl) isocyanurate, and 0.0110% by weight diphenyl silane diol.
8. A resin composition according to claim 7 wherein said hydantoin is 1,3 dihydroxyethyl-5,5-dimethyl hydantoin.
9. A resin composition according to claim 1 wherein said composition includes a tetraalkyl titanate.
10. An electrical conductor having a coating of the composition of claim 1.
11. An electrical conductor having a coating of the composition of claim 3.
12. An electrical conductor having a coating of the composition of claim 7.
13. An electrical conductor having a coating of the composition of claim 8.
References Cited UNITED STATES PATENTS 3,681,282 8/1972 Preston 26046.5 E
3,342,780 9/1967 Meyer et a1. 26077.5 NC
DONALD E. CZAJA, Primary Examiner M. I. MARQUIS, Assistant Examiner US. Cl. X.R.
117135.1; 2602 S, 18 S, 30.8 DS, 32.6 R, 32.8 SB, 33.4 SB, 33.6 SB, 33.8 SB, 77.5 R, 77.5 NC, 77.5 AM, 824, Dig. 34