CA1056990A - Polyester, synergistic cross-linking system, wire coating composition - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A composition is prepared which is useful in wire enamel, comprising (1) a water soluble polyester which is a condensation product of (a) a tribasic carbox-ylic acid, (b) an aliphatic or aromatic dicarboxylic acid and (c) a dihydric alcohol, (2) hydroxymethylated diace-tone acrylamide as a crosslinking agent and a water solu-able organic titanate.

Description

10~6990 The present invention relates to the compositionof a water soluble polyester for use as a wire enamel or protective coating.
Water soluble trimellitic anhydride polyesters are known in the art, U.S. Patent to Bremmer, No.
3,070,256. However~ an unmodified polyester with a nylon 6-6 top coat was found to be inadequate to provide both heat shock and cut-through properties that are required for a commercial class F magnet wire enamel. Without the nylon top coat, the heat shocks were even worse.
It has been discovered that use of hydroxy-'methylated diacetone acrylamide as a crosslinking agent improves the heat shock properties of the polyester coat-ing. It has been further discovered that u9e of a water 15 soluble organic titanate as a crosslinking agent in the ~
polyester improves the cut-through values, but downgrades ~ `
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~the heat shock propertiesO It has also been discovered . ~ .
that incorporation of both of these crosslinking agents unexpectedly improves both of the above-mentioned proper- `
ties of the enamel coating.
It is an object of the present invention to pre-pare a new water soluble polyester.
Another object is to improve such a polyester coating with the addition of hydroxymethylated diacetone acrylamide.
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1~56990 A further object is to prepare an improved poly-ester by the addition of hydro~ymethylated diacetone acryl-amide and a water soluble organic titanate.
An additional object is to prepare a polyester coating with improved heat shock and cut-through proper ties Still further objects and the entire scope of applicability of the present invention will become appar-ent from the detailed description given hereinafter; it should be understood, however, that the detailed descrip-` tion and specific examples, while indicating preferred em-bodiments of the inventionO are given by way of illustra-tion only, since various changes and modification within the spirit and scope of the invention will become appar-. 15 ent to those skilled in the art from their detailed de-scription.
These objects are attained by mixing together (1) a water soluble polyester which is a condensation prod-uct of (a) a tribasic carboxylic acid, ~) an aromatic di-carboxylic acid which can be replaced in part by an ali-phatic or cycloaliphatic dibasic acid and (c) a dihydric alcohol; (2) hydroxymethylated diacetone acrylamide (HMD~A - a trademark of Lubrizol Corp.), as a crosslinking - agent, and (3) a water soluble organic titanate may be added to the mixture in order to improve cut-through prop-

-3-, '' . ' lOS6990 erties of the coating. A synergistic effect has been found when both (2) and (3) are present.
It i9 critical to have at least a predominant amount of aromatic dicarboxylic acid such as terephthalic acid or a combination of terephthalic acid and isophthalic acid since it is only when the aromatic dicarboxylic acid predominates that substantial improvements in heat shocka and especially in cut-throughs are obtained to satisfy a Class F rating.
The new composition of the present invention is , applied to a silver, copper or any other metal wire by an aqueous solution containing the water soluble polyester, HMD~A and the water soluble organic titanate. The present composition can be sold on a dry basisjor in an aqueous solution. The concentrations of the total solids (poly-,' ester, HMDAA and titanate) in the aqueous solution i~ not critical.
one or more tribasic acids (including anhydrides of such acids) may be employed alone or in combination with a tetrabasic acid. Some suitable acids which areuseful in the present invention are as followso Triacids - Trimellitic acid or preferably its ~ -anhydride, trimesic acid, hemimellitic acid, tris (carboxyethyl) isocyanurate, nitrilo-triacetic acid, etc.;

Tetra acids - Pyromellitic acid or anhydride, benzophenone tetracarboxylic acid or anhy-~` :

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dride, cyclopentane tetracarboxylic acid oranhydride, etc.
The preferred tribasic acid is trimellitic anhydride.
For the dicarboxylic acid, one or more aromatic dicarboxylic acids (including anhydrides of such acids) or a combination of an aliphatic or cycloaliphatic acid (or anhydride thereof) and the arGmatic acid may be employed.
~ Some suitable acids are as follows:
i Carboxylic Acids Diacids - a) Ali~hatic - succinic acid, glutaric acid, ; adipic acid, pimelic acid, suberic acid, ~ azelaic acid, sebacic acid, diglycolic acid, ;,~ 1,12-dodecanoic acid, tetrapropenyl succinic t~ anhydride, maleic acid and its anhydride, fumaric acid, itaconic acid and its anhy-dride, malic acid, etc.

b) Cvcloaliphatic - tetrahydrophthalic anhy- ~-dride, hexahydrophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, etc.

c) Aromatic - phthalic acid, phthalic anhy-dride, isophthalic acid, terephthalic acid, ;--benzophenone dicarboxylic acid, diphenic acid, 4,4'-dicarboxydiphenyl ether, 2,5-pyridine dicarboxylic acid, etc.
The preferred aromatic dicarboxylic acids are isophthalic acid, terephthalic acid, and the preferred ali-~I phatic acid is maleic anhydride.
:, :One or more dihydric alcohols may be u ed alone or in combination with other triols or higher polyhydric alcohols. Alcohols that may be employed in the prepara-tion of the polyester are: ~
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Diols -ethylene glycol, propylene glycol, 1-3 butylene glycol, 1,5-pentanediol; 1,6-hex-anediol, neopentyl glycol, diethylene gly-col, dipropylene glycol, 1,3-hydroxyethyl- ` -5,5-dimethylhydantoin, 1,4-cyclohexanedi-methanol, 1,4-cyclohexanediol, hydrogenated bisphenol A (hydrogenated isopropylidene di-phenol) Union Carbide's "Ester Diol 204, -$ (2,2-dimethyl-3-hydroxyscopyl 2,2-dimethyl-3-hydroxypropionate)" Dow 565 (diether of propylene glycol and Bisphenol A), Carbowax --150 (polyethylene glycol with avg. ~ of 150), Carbowax 1500 (Polyethylene glycol molecular -weight average 1500 and is a blend ~ ~-of equal parts of Carbowax 300 and Carbowax -1540), etc. ~-Triols -glycerine, trimethylolethane, trimethylol-propane, trishydroxyethyl isocyanurate (THEIC), 1,2,6-hexanetriol, polyether triol (avg. mol. wt. 230 ethoxylated or propoxyl-ated glycerine), etc.
.
Hiqher PolYols - pentaerythritol, dipentaerythritol, tri-pentaerythritol, Monsanto'S RJ-100 (styrene-allyl alcohol copolymer with avg. mol. wt.
1600), etc.
;~ The preferred alcohols are ethylene glycol, 1,3-hydroxy-( ethyl-5,5-dimethylhydantoin, 1,6-hexanediol, diethylene .~ . glycol, and THEIC.
The organic titanate may be a chelate such as a :.! 30 tetra triethanolamine chelate of titanium, available in a ` 5096 aqueous solution as Tyzor TE from duPont. Illustra-.
tive of another suitable water soluble titanate is Tyzor L~ which is lactate ammonium salt chelate of titanium (509 ~ aqueous solution) Tyzor LA is the preferred organic ti-;~ 35 tanate.
The HMDAA is a hydroxymethylated derivative of .

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lVS~990 diacetone acrylamide. The diacetone acrylamide, also known as N-3-oxohydrocarbon-substituted acrylamide, is described in Coleman, U.S. Patent No. 3,277~056. The hydroxymethyl groups are attached to the carbon atoms alpha to the keto carbonyl. Further properties of HMDAA are described in a brochure entitled ~HMDAA Monomer" published by the Lubrizol Corporation. Unless otherwise stated all parts and per-centages are by weight. The concentrations of HMDAA may ; be from 0.1 to 6 weight percent or even up to 10% based on a dry weight of the total solids, including the polyester.
The water soluble organic titanate may be from 0.5 to 10 weight percent based on the dry weight of the total solids, . including the polyester. On a preferred basis the ratio ~, of the organic titanate to the HMDAA on a dry solids basis would be 7 to 25% of the titanate to 93 75% of HMDAA.
In the preparation of the polyester, the propor-tions of the alcohols to the acids have been calculated on equivalents of hydroxyl and carboxyl groups. The propor-', tion is not critical and one skilled in the art can deter-mine the proportion for various uses. The preferred range is an excess of hydroxyl groups over carboxyl groups by an amount ranging from 10 to 50%. A more preferred excess hydroxyl content is 20 to 35%.
` The molar ratio of the primary tribasic acid (when employed) i.e. that tribasic acid which has a greater .

molar concentration than any other tribasic or tetrabasic acid, to the other acids, including the dicarboxylic acids, and other tribasic and tetrabasic acids is usually in the range from 25/75 to 85/15. Of course there can be used the primary tribasic acid itself without any other tribas-ic or tetrabasic acid. The term acid is intended to cover anhydrides when they exist.
The amount of alcohols may be entirely one or more dihydric alcohols or a combination of dihydric alco-hols and triols or higher polyhydric alcohols. If a com-bination of alcohols is usedO one skilled in the art can easily determine the proper proportion of each since it ; is not critical. The~preferred ratio of dihydric alcohols to triols or higher polyhydric alcohols is in the range ~ 15 of 97~3 to 65/35 on a molar basisO The trihydric alcohol ;~1, can be omitted, particularly if a tribasic acid is employ-ed as a part of the acid.
The amount of aliphatic and cycloaliphatic di-carboxylic acid can be 0 to 0.50 moles per mole of aromat-ic dicarboxylic acid. If present, the aliphatic or cyclo-; aliphatic dicarboxylic acid can be as little as 0.01 mole per mole of aromatic dicarboxylic acid. The preferred range of aliphatic and cycloaliphatic acid is 0 to 0.30 mole per mole of aromatic dicarboxylic acid.
Per mole of total dicarboxylic acid there are usually employed 1.87 to 4.91 moles of diol (dihydric al-cohol) and 0.33 to 1.86 moles of tricarboxylic acid.
The use of the HMDAA and water soluble titanates is critical. Other cross-linkers such as water-soluble aminoplasts cause blistering during application on wire and even where the coated wire is barely acceptable con-siderable weight loss is experienced during heat aging.
Water soluble phenolic resins cause considerable embrittle-ment of the wire so that it does not pass the snap test in any reasonable mandrel after snap test.
~ As stated above, the HMDAA and water soluble ti-: tanates act as a synergistic combination of cross-linking agents. This can be seen from the illustrative example below.
i 15Examples 1-11 disclose various methods for mak-ing the polyester component of the composition~
Example 1 Weight Reactants Grams Mols.
20 (A) Ethylene Glycol 1,3-Hydroxyethyl 543 8.76 (B) -5,5 dimethylhydantion 337 1.56 (C) Isophthalic Acid 349 2.10 (D) Nitrilo triacetic Acid 29 0.15 (E) Trimellitic Anhydride 720 3.75 ; 25 Materials A, B, C and D were charged into a 5 liter, three-neck flask equipped with agitator, gas inlet tube, thermom-eters for flask and distilling head, 3-bubble cap Snyder fractionating column and water-cooled condenser. Prior to heating the flask's contents nitrogen was sparged into the flask for 15-30 minutes to displace the air present, and continued throughout the course of the esterification ' process. Heat was applied and the batch temperature was gradually raised to 360-410F. in a matter of 2 to 4 hours.
More importantly, the distilling head temperature was con-trolled at 200-212F. to minimize glycol losses.
The batch was held until the resin melt was a clear hot melt and 65-75 mls. of distillate had been col-lected. The contents were allowed to cool to 300F., and material E was added to the flask. After replacing the Snyder column and distilling head with a Dean-Stark water trap heat was reapplied and the temperature raised to a range of 330-350F. It was maintained at that top temper-ature range and sampled periodically for viscosity and acid number. The polyester was controlled to a final vis-cosity of B-E on the Gardner-Holdt scale at 5~% solids in methyl cellosolve~acetate. The acid number of the solution was between 30 and 40.
~` When this end point was reached the contents were cooled to 200-220F. and a mixture of ammonium hydrox-ide (28-3~% NH3) and deionized water was carefully added to the flask by means of a dropping funnel. It was ad-lOS~i990 - justed to a viscosity of Ul/2-W on the Gardner-Holdt scale and a pH 7.5-8.5 with the requisite amount of ammonia and water.

Exam~le 2 Weight Reactants Grams Mols.

, (A) Ethylene Glycol 536 8.64 (B) 1,6-Hexanediol 177 1.50 (C) Terephthalic Acid338 2.04 10 (D) Dibutyl Tin Oxide2~2 (E) Isophthalic Acid 60 0.36 (F) Trimellitic Anhydride 691 3.60 . .~ .
The same equipment was used as in Example 1, ex-cept for the elimination of a nitrogen sparge in the first ~ 15 stage of the reaction. Materials A, B, C and D which i9 j employed as a catalyst, were raised to 380-410F. and main-tained there until the hot melt was clear, and 60-70 mls.
of distillate had been collected.
The batch was cooled to 350F. and material E
20 was added. At this juncture the flask was spargea with ~ -nitrogen, and temperature raised again to 380-420F. Aft-, er collecting another 10-15 mls. of distillate the contents `¦ were cooled again to 300F.
~ Material F was added at 300F. or less. After `~ 25 replacing the Snyder column and distilling head with a water trap heat was reapplied and the temperature raised -: .: , , to a range of 330-350F.
The batch was monitored at periodic intervals and controlled to a final viscosity of B-E on the Gardner--~ Holdt scale at 5~ solids in methyl cellosolve acetate (MCA). The acid number of the solution was between 30 ' and 40.
The molten resin at 200-220F. was subsequently diluted with deionized water and ammonium hydroxide to a final viscosity of S-T and pH of 7.6.
Example 3 , Weight Reactants Grams Mols.
(A) Ethylene Glycol 524 8.46 (B) 1,6-Hexanediol 177 1.50 15 (C) Isophthalic Acid 448 2.70 ~, (D) ~rimellitic Anhydride 634 3.30 The same equipment and procedure were employed as detailed in Example 1. After 75-85 mls. distillate were collected in the initial stage material "D" was charged to the flask, reaction was continued to a final viscosity of A-D and acid number of 25-35 at S0~ solids in methyl cellosolve acetate (~CA).
, An aqueous solution was prepared in the same manner as in Example 1 and adjusted to the same viscosity and pH ranges as in that example with a dilute ammoniacal solution.

-Example 4 Weight Reactants Grams Mols.
(A) Ethylene Glycol 483 7.80 (B) Diethylene Glycol 166 1.56 (C) Terephthalic Acid 398 2.40 (D) Dibutyl Tin oxide 0.5 (E) Isophthalic Acid 200 1.20 (F) Trimellitic Anhydride 461 2.40 The same equipment and procedure were employed as detailed in Example 2. In the initial stage of the cook with materials A, B, C and D the reaction was regu-lated to a point where 80 mls. distillate were collected. ~' ~, After the addition of material E another 40 mls.
distillate were collected in this second or intermediate stage.
Material F was added at 300F., and the reaction ;~
brought to completion at a final viscosity of A-C and an acid number of 25-35 at 50~ solids in MCA.
An aqueous solution was prepared in the same man-ner as described in Example l as to viscosity, pH and solu-bilizing agent employed.
Example 5 Weight Reactants Grams Mols.
(A) Ethylene Glycol 502 8.10 . .

, Example 5 (Continued) (B) Diethylene Glycol 134 1.26 (C) Terephthalic Acid 548 3.30 (D) Dibutyl Tin oxide 0.25 5 (E) Isophthalic Acid 50 0.30 (F) Trimellitic Anhydride 461 2.40 The same equipment and procedure were employed as detailed in Example 2. Materials A, B, C and D were charged to flask, and temperature slowly raised to 390-430F. Reaction was continued until 98 mls. of distillate had been collected.
The contents were cooled to 350F., and material E was added. A nitrogen sparge was used at this point, and esterification resumed. After 10-20 mls. additional 15 distillate had been collected, the contents were cooled again to 300F.
n Material "F" was added at 300F., and heat was applied again. The temperature was maintained at 345-365 F. until a viscosity of A-D and an acid number of 25-35 20 at 50~ solids in MCA was attained.
An aqueous solution was prepared in the same man-ner as described in Example 1 as to viscosity, pH and solu-bilizing agent employed.

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105t;990 Example 6 Weight Reactants Grams Mol~.
(A) Ethylene Glycol 491 7,92 (B) Diethylene Glycol 134 1.26 ~-(C) Terephthalic Acid 249 1.50 (D) Dibutyl Tin Oxide 0.25 (E) Terephthalic Acid 248 1.50 (F) Trimellitic Anhydride 403 2.10 ' (G) Maleic Anhydride 88 0.90 The same e~uipment and procedure were employed as detailed in Example 2. In the initial stage of the re~
action 40-50 mls. of distillate were collected. After the second stage another 50-60 mls. distillate were obtained.
In the final step the product was carried to a final viscosity of A-C and an acid nun~ter of 26-34 at 50%
901ids in MCA, The molten resin was solubilized in water and ammonium hydroxide in the same manner as described in Ex-' 20 ample 1.

Example 7 :t Weight Reactants Grams Mols.
(A) Ethylene Glycol 521 8.40 (B) Diethylene Glycol 193 1.82 (C) Terephthalic Acid 349 2.10 .. :

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lOSt;990 (D) Dibutyl Tin Oxide 0.25 (E) Terephthalic Acid 348 2.10 (F) Trimellitic Anhydride 336 1.75 (G) Maleic Anhydride 103 1.05 The same reaction conditions and equipment were , employed as in Examples 2 and 6. Seventy mls. di~tillate were obtained in the first step of the process. Another - 64 mls. distillate were collected in the second step.
In the final step the reaction was stopped when a viscosity of A and an acid number 25-29 at 5~h NVM [non-volatile materials] in MCA were achieved.
For the preparation of the aqueous solution us-ing this polymer base consult Example 1.
~, Example 8 Weight Reactants Grams Mols.
(A) Ethylene Glycol 442 7.14 (B) Diethylene Glycol 193 1.82 (C) Terephthalic Acid 349 2.10 20 (D) Dibutyl Tin Oxide 0025 (E) Terephthalic Acid 348 2.10 (F) Trimellitic Anhydride 336 1.75 (G) Maleic Anhydride 103 1.05 (H) Glycerine (96%) 81 0.84 The same equipment and reaction conditions were used as in Examples 2, 6 and 7. In the first stage 64 mls.
: -16-distillate were collected. Another 71 mls. distillate were obtained in the second stage. In the third and final stage, the reaction was terminated at a viscosity of B and an acid number 30.5 at 50% NVM in MCA. ~;
Its aqueous solution was prepared in the same manner as described in Example 1.
Example 9 Weight Reactants Grams Mols.
10 (A) Ethylene Glycol 442 7.14 (B) Diethylene Glycol 193 1.82 (C) Terephthalic Acid 349 2.10 (D) Dibutyl Tin Oxide 0.25 (E) Terephthalic Acid 348 2.10 15 (F) Trimellitic Anhydride 336 1.75 (G) Maleic Anhydride 103 1.05 (H) Trishydroxyethyl isocyanurate 219 0.84 Formulation of this example was similar to Ex-ample 8, except for the replacement of glycerine with 20 tris(hydroxyethyl) isocyanurate. The reaction conditions and equipment were the same as in Examples 2 and 8.
The final constants achieved for this polyester `' base were a viscosity of A 1/2 and an acid number of 30.8 at 5096 solids in MCA.
' 25 Its aqueous solution was prepared in the same manner as described in Example 1.

' `' ' - -;, ' " ~ ' , ' , ' ~ : ' ' ExamPle 10 Weight Equiv-Reactants Grams Mols. alents (A) Ethylene Glycol 498 8.04 16.08 5 (B) Diethylene Glycol 159 1.50 3.00 (C) Terephthalic Acid 249 1.50 3.00 (D) Dibutyl Tin oxide 0.25 (E) Terephthalic Acid 249 1.50 3.00 (F) Pyromellitic Diar~ydride 131 0 .60 2 .40 10 (G)- Trimellitic Anhydride 288 1.50 4.50 (H) Maleic Anhydride 88 0.90 1.80 The same equipment and procedure were employed as detailed in Example 2. In the initial stage of the re-action 40-50 mls. of distillate- were collectecl. After the 15 second stage, another 42-48 mls. of distillate were obtain-ed.
Material "F" was added at 300F., and the tem-perature raised to 400F. in two hours. A top tempera-ture of 400-410F. was maintained until an additional 10-20 15 mls. of distillate were collec~ed.
After cooling to 300F. materials "G" and "H"were charged to the reaction vessel. The Snyder column was removed, and replaced with a Dean-Stark water trap con-nected to a water-cooled condenser. Also, a gas inlet 25 tube was attached to a side neck and the batch was slowly sparged with nitrogen. -18-.

In two hours the temperature was raised to 350-360F. It was maintained at that top temperature range, and monitored periodically for viscosity and acid number.
The polyester was controlled to a final viscosity of F-G
on the Gardner-Holdt scale at 5G% solids in methyl cello- , solve acetate (MCA). The acid number of the solution was 28, The molten resin at 200-220F. was subsequently diluted with deionized water and ammonium hydroxide to a final viscosity of V 1/2, pH of 8.1 and solids of 2205%.
Example 11 Weight Equiv-Reactants GramsMolS. alents (A) Ethylene Glycol 498 8.0416.08 15 (B) Diethylene Glycol 159 1~503.00 (C) Terephthalic Acid 249 1.503.00 . (D) Dibutyl Tin Oxide 0.25 (E) Terephthalic Acid 249 1.503.00 (F) Benzophenone Tetracarboxylic 193 0.60 2.40 Dianhydride (G) Trimellitic Anhydride 2881.50 4,5Q
(H) Maleic Anhydride 88 0.901.80 The same equipment and procedure wsre employed as detailed in Examples 2 and 10. In the first and second stages of reaction or esterification of terephthalic acid 'with the mixed glycols the quantities of distillate were .` -19-lOS699(J

similar to that cited in Example 10.
Material "F" was added at 300F., and the tem-perature increased to ~00F. in two hoursO This top tem-perature was held until an additional 10-15 mls. of dis-tillate were collected.
Materials "G" and "H" were charged to the flask at 300F., and reacted in similar fashion to these same materials in Example 10.
The reaction was regulated by monitoring the viscosity and acid number of the polymer formed. After attaining a viscosity of B-C and an acid value of 31.9% at 50% solids in MCA, the molten resin was cooled to 220F., , and solubilized in dilute ammoniacal water.
The aqueous solution was adjusted to a viscos-15 ity of V 1/2, a pH of 7.95 and a solids content of 32~. -Table A summarizes the moles of acids used in pl99 1 to 11.

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lOS6~90 The heat shock te~t employed in the following tables uses the conventional test published in NEMA Stand-ards Publication ~W-1000-1973, ANSI C9. 100-1973 Magnetic Wire Section, Part 3 - l`est Procedures, page 4, Test 4, 5 1.1.
The following tables disclose the improved prop-erties of the enamel coating when the polyester is combin-ed with a combination of HMDAA and a water soluble organic titanate.
Table I
Parts by Weiqht Enamel Nos. 1 2 3 Polyester of Example 3 630 Aqueous Soln. of Ex. 3 (EnamelNo. 1) 650 650 ~ 15 Water (deionized) 1315 `~! Ammonium hydroxide (28% NH3) HMD,~A 11.5523.8 Solution C~aracteristics Viscosity (Gardner-Holdt Scale) Vl/4Ul/2Ul/2 p~ 7.997.65 7.6 % Solids 31.631.8532 .4 % Crosslinker (on a total æolids basis) 0 3 6 (over AWG No. 18 Copper Wire coated with 2 mils, 25 polyester base and 1 mil nylon top coat) ~0~6990 Wire Pro~ertie~
:
Enamel Nos. 1 2 3 Heat Shock, lX mandrel 0 30 mins. at 175C
2X mandrel 40 90 90 3X mandrel 90 100 80 20% pre-stretch 4X mandrel 100 100 100 Cut-through Temp., C.182-193198-210 167-172 To further demonstrate the combined effect of HMDAA and Tyzor LA as cross-linking agents toward the im-provment of both heat shock and cut-through characteristics of the unmodified enamel prepared from the base of Example 7. For details consult Table II. ~ -; Table II
Parts bY Weiqht -Enamel Nos. 4 5 6 Polyester of Example 7 840 Aqueous Soln. of Ex. 7 (Enamel No. 1) 600 600 Water (deionized) 1490 20 Ammonium Hydroxide (28% NH3) 65 HMD~A 11.6311.63 Tyzor LA 2.24 4.4 .
i Solution Characteristics ~-`3 Viscosity (Gardner-Holdt Scalel V 1/4 V V 1/2 pH 8.0 7.51 7.75 % Solids 35.1 35.5 35.6 . ~ - . , ~ . .
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4 5 6 % Crosslinker, E~MDAA 3 3 % Tyzor LA 0.5 (over AWG No. 18 copper wire base coat: 2 mils of Enamel top coat 1 mil Nylon 6, 6) Wire Properties Enamel Nos. 4 5 6 Heat Shock lX mandrel 80 20 10 2X mandrel 100 80 80 3X mandrel 100100 90 4X mandrel 100100 100 Cut-Through Temp. C. 162-185 230 235 215-240 In order to 9how the superiority of the use of ' both hydroxymethylated diacetone acrylamide (HMDAA) and a water soluble organic titanate as cross-linking ~gents in preparing a wire enamel from a water soluble polyester ex-20 periments were carried out as set forth in Table III.
Table III
Enamel Nos. 1 2 3 4 Polyester of Example 4 840 Aqueous Soln. of Ex. 4 550 550 550 25(Enamel No. 1) Water (deionized) 1650 ' ." ` : , . . .

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Table III (cont'd) Enamel Nos. 1 2 3 4 Ammonium Hydroxide 70 HMDAA 10.15 10.15

5 Tyzor LA 3.65 3.90' Solution Characteristics 1 2 3 4 ~, Vi~c08ity (Gardner-Holdt V U 1/4V 1/2 V 1/2 Scale) pH 8.30 7.73 7.757.87 10 % Solids 32.0 33.1 33O033.3 ; % Cro~slinker (on a total 0 3 1 4 801idg basis ) Specific Gravity, 25C 1.095 1.095 1.095 1.095 - (over AWG No. 18 Copper Wire coated with 2 mils i polye~ter base and 1 mil Nylon topcoat) ~
Wire ProDerties ` ~ -Enamel Nos. 1 2 3 4 20 Heat Shockq: lX mandrel 0 20 10 10 30 min at 175C 2X mandrel 6030 30 -- 40 20~ pre-stretch 3X mandrel 7060 30 80 4X mandrel 90 70 70 ~ 100 Cut-Through Temp., C. 151-180 135-140 208-215 210-218 Speed, ft./min. 50 50 5050 Appearance 3 3 33 Mandrel, after snap lX lX lX lX
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~056990 It will be observed that in the tables enamels 1 and 4 of Table II had no cros's-linking agents present and thus had poorer heat shocks and much poorer cut-throughs than enamels 5 and 6 which have the cross-linking agents or curatives, as can be seen also in comparing enamels 1 and 4 in Table III.
Table I demonstrates that when only HMDAA is employed at the 3% level of cross-linking agent there is : some improvement in cut-throughs and heat shocks but at the 6% level of HMDAA in Example 3 there is a precipito~s -~ drop in cut-throughs while maintaining the heat shocks.
' Thus HMDAA alone falls short.
The products can comprise, consist of or con-sist es~entially of the materials set forth.

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Claims (22)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A composition comprising:

1. A water-soluble polyester which is a condensation product of a polycarboxylic acid and a polyhydric alcohol said polycarboxylic acid comprising (a) a tribasic carboxylic acid and (b) an aromatic dicarboxylic acid with 0 to 0.50 mol of an aliphatic or cycloaliphatic dicarboxylic acid per mol of the aromatic dicarboxylic acid, said polyhydric alcohol comprising a dihydric alcohol, the molar ratio of tribasic carboxylic acid to the other acids present being from 25/75 to 85/15, there being present an excess of hydroxyl groups over carboxyl groups in said polyester in the range of 10 to 5 percent, 2. hydroxymethylated diacetone acrylamide in an amount of 0.1 to 10 percent by weight of the total solids as a cross-linking agent for said polyester, and 3. 0.5 to 10 percent by weight of the total solids of a water-soluble organic titanate as a synergistic cross-linker with (2).

2. The composition of Claim 1, wherein the tribasic carboxylic acid is selected from the group consisting of tri-mellitic acid, trimellitic anhydride, trimesic acid, hemi-mellitic acid, tris(carboxyethyl) isocyanurate and nitrilotri-acetic acid.

3. The composition of Claim 1, wherein the amount of aliphatic and cycloaliphatic dicarboxylic acid is 0.

4. The composition of Claim 1, wherein the amount of aliphatic and cycloaliphatic dicarboxylic acid is 0.01 to 50 mol per mol of aromatic dicarboxylic acid.

5. The composition of Claim 1, wherein the organic titanate is selected from the group consisting of triethanol-amine chelate of titanium and the lactate ammonium salt chelate of titanium.

6. The composition of Claim 1, wherein the polybasic acid component of the water-soluble polyester includes a tetra-carboxylic acid from the group consisting of pyromellitic acid, pyromellitic anhydride, benzophenone tetracarboxylic acid, benzophenone tetracarboxylic anhydride, cyclopentane tetra-carboxylic acid and cyclopentane tetracarboxylic anhydride.

7. The composition of Claim 1, wherein the poly-hydric alcohol component of the polyester includes a polyhydric alcohol having at least three hydroxyl groups and selected from the group consisting of glycerine, trimethylolethane, tri-methylolpropane, tris(hydroxyethyl) isocyanurate, 1,2,6-hexane-triol, ethoxylated glycerine, propoxylated glycerine, penta-erythritol, dipentaerythritol and styrene-allyl alcohol co-polymer.

8. The composition according to Claim 2, wherein the range of excess hydroxyl groups is 20 to 35 percent.

9. The composition according to Claim 1, wherein the tribasic carboxylic acid is selected from the group consisting of:
trimellitic acid, trimellitic anhydride, trimesic acid, hemimellitic acid, tris(carboxyethyl) iso-cyanurate, and nitrilotriacetic acid;

the aliphatic or cycloaliphatic dicarboxylic acid is selected from the group consisting of:
succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, diglycolic acid, 1,12-dodecanoic acid, tetra-propenyl succinic anhydride, maleic acid, maleic anhydride, fumaric, itaconic acid, itaconic anhydride, malic acid;
tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 1,4-cyclohexanedicarboxylic acid;
the aromatic dicarboxylic acid is selected from the group consisting of:
phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, benzophenone dicarboxylic acid, diphenic, 4,4-dicarboxydiphenyl ether, and 2,5-pyridine dicarboxylic acid;
and the dihydric alcohol is selected from the group consisting of:
ethylene glycol, propylene glycol, 1-3 butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,3-hydroxyethyl-5,5-dimethylhydantoin, 1,4-cyclo-hexanedimethanol, 1,4-cyclohexanediol, hydrogenated isopropylidene diphenol, 2,2-dimethyl-3-hydroxy-propyl, 2,2-dimethyl-3-hydroxypropionate, diether of propylene glycol and hydrogenated isopropylidene diphenol, and polyethylene glycol.

10. An aqueous solution comprising water and the composition according to Claim 9.

11. The composition according to Claim 9, wherein the water-soluble polyester includes a tetrabasic carboxylic acid.

12. The composition according to Claim 9, wherein the water-soluble polyester includes a polyhydric alcohol having at least three hydroxyls.

13. The composition of Claim 9, wherein the aromatic dicarboxylic acid is terephthalic acid or a mixture of tere-phthalic acid and isophthalic acid.

14. The composition according to Claim 13, wherein the organic titanate is selected from the group consisting of triethanolamine chelate of titanium and lactate ammonium salt chelate of titanium.

15. The composition according to Claim 13, wherein the aromatic dicarboxylic acid is terephthalic acid.

16. The composition according to Claim 15, wherein the hydroxymethylated diacetone acrylamide comprises 0.1 to 6 percent by weight of the total solids.

17. The compositions according to Claim 16, wherein in the ratio between the hydroxymethylated diacetone acrylamide and organite titanate on a dry solids basis is in the range of 7 to 25 percent of the titanate and 75-93 percent of the hydroxymethylated diacetone acrylamide.

18. The composition of Claim 13, wherein the tri-carboxylic acid is trimellitic anhydride.

19. The composition according to Claim 10, wherein the tribasic carboxylic acid is selected from the group con-sisting of trimellitic anhydride and nitrilotriacetic acid, the aliphatic or cycloaliphatic dicarboxylic acid is present and is maleic anhydride, and the dihydric alcohol is selected from the group consisting of 1,3-hydroxyethyl-5,5-dimethylhydantoin, ethylene glycol, 1,6-hexandiol and diethylene glycol.

20. A composition according to Claim 19, wherein the polyester includes a trihydric alcohol selected from the group consisting of glycerin and tris(hydroxyethyl) isocyanurate.

21. The composition according to Claim 19, wherein the hydroxymethylated diacetone acrylamide comprises 3 to 6 percent by weight of the total solids.

22. An aqueous solution comprising water and the composition according to Claim 19.