JPS5953304B2 - Covered conductor and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coated conductor and a method for manufacturing the same.

Polyester-imide wire coatings diluted with cresylic acid/aromatic hydrocarbon mixtures have been used commercially for several years.

By taking the base polymer and using it with an amine, it can be dissolved in water. When attempting to use the same hardening agents as those used in the water-insoluble or organic solvent-based systems described above, it was discovered that these hardening agents were insoluble in water. As a result, the search for water-soluble cross-linking agents has been necessary, and the results have mainly focused on organic titanates, such as Tyza-TE and LA (Ty
zOrTE and LA), titanium chelate of triethanolamine and ammonium lactate salt, served as crosslinking agents. The teachings of Mayer et al., U.S. Pat. No. 3,426,098, the details of which are incorporated herein by reference.

), obtain a conventional polyester-imide base polymer, dissolve it in distilled water, an amine, and a polar solvent,
Even if modified with Tizer-TE, the surface baked onto the copper wire is uneven, lacks roundness, and has many grains and is coarse due to poor flow characteristics in the wire tower during the bake-hardening operation. be. Other standard polyester-imide-based enamels with a diimide diacetate molar content determined with respect to the terephthalic acid molar content are used in large-scale wire towers, such as the presence or absence of large grains and/or roughness or blistering It is operated based on a graded appearance evaluation (the lower the number, the better the performance). It is therefore an object of the present invention to provide a coated electrical conductor comprising a wire enamel coated with a completely water-soluble, clear-looking wire enamel prepared using a novel polyester-imide, and a method for producing the same. At the point.

Another object is to provide improved heat resistance by coating a novel wire enamel containing a polyester-imide that is not only water-soluble but also soluble in conventionally known cresylic acid/aromatic hydrocarbon mixed solvents. An object of the present invention is to provide a conductor having a coating and a method for manufacturing the same. Another object of the present invention is to provide a conductor coated with wire enamel which has superior flexibility and flame impact resistance compared to conventionally known polyester wire enamels. Still other purposes include polyethylene terephthalate, nylon or amide
2 without providing a top coat using imide polymer
The object of the present invention is to provide a conductor coated with heat-resistant wire enamel having excellent heat shock resistance at 00°C. The present inventors have discovered that the above objects of the present invention can be achieved by obtaining a polyester-imide that is essentially different in the following three respects compared to conventionally known polyester-imides for use in organic solvents. That is, (1) the polyimide content is high, that is, the content is 3.5% or more.

(2) Hydroxyl content is 60% or more, preferably 10
0% or more excess, so the 0H/COOH ratio is 1.8/1 to 2.50/1, preferably 2.20 to 2.
The ratio should be 50/1.

(3) The number average molecular weight of the base polyester-polyimide is smaller than that for organic solvents; that is, the conventional type is 1300 or more, while the new polymer of the present invention is 600 to 1300. thing.

The polyimide content can be 5 to 60%, preferably 35% to the total amount of polyimide and polyester.
~55% amount.

In the present invention, unless otherwise specified, parts and percentages are parts by weight.

Constituent components of the polyimide include (a) an anhydride such as trimellitic anhydride, and (b) a polyamine, preferably an aromatic polyamine, such as methylene dianiline, oxydianiline, phenylene diamine, etc. can be used.

Further, the anhydride (a) includes aromatic tricarboxylic anhydrides such as 3,4,3'-benzophenone tricarboxylic anhydride, hemimellitic anhydride, and the like. Other anhydrides include those shown by Mayer et al. in US Pat. No. 3,426,098. However, the preferred anhydride Vj(a) is trimellitic anhydride. Other polyamines (b) include 3,3″-diaminodiphenyl, benzidine,
1,4-diaminonaphthalene, P-phenylene dianine, ethylene diamine, nonamethylene diamine, hexamethylene diamine, diaminodiphenyl ketone, bis(4
-aminophenyl)-α,α″-P-xylene, m-phenylenediamine, m-xylenediamine, 4,4′-
Cyclohexylmethanediamine, diaminodiphenyl sulfone, octamethylene diamine, P-xylene diamine, 3,3"-dichlorobenzidine, 3,3"-dimethylbenzidine, 3,4"-diaminodiphenyl ether, 4,4-diaminodiphenyl Enylpropane, 3,3''-diaminodiphenyl sulfone, and the like. However, preferred diamines are methylene dianiline and oxydianiline. Reaction components (5) and (b) are usually 1
Approximately 2 molar amounts of (a) are used relative to the molar amount of (b) to form a diimide diacid.

This reaction product is represented by the following formula. In the formula, R is CH2 in the case of methylene dianiline, and is an oxygen atom (D) in the case of oxydianiline.

In the formula representation of the polymer, the diimide-diacid is taken into account as part of the total dicarboxylic acids, which are mostly aromatic dicarboxylic acids, but may or may not also contain small amounts of aliphatic dicarboxylic acids. It is.

A preferred aromatic dicarboxylic acid is terephthalic acid, but
Benzophenone-4,4''-dicarboxylic acid is likewise preferred, and isophthalic acid and mixtures thereof are almost equally preferred.Other aromatic dibasic acids include naphthalene-1,4-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, and naphthalene-1,4-dicarboxylic acid. 1,5-dicarboxylic acid, 4,,4''-dicanoleboxydiphenynolesulfone, 3,3'-dicarboxydiphenynolesulfone, 4,4''-dicarboxydiphenyl ether, 4, 4″-dicarboxydiphenylmethane, 4,4″-dicarboxydiphenylketone, 4,4
''-dicarboxydiphenylpropane, etc. Examples of aliphatic dicarboxylic acids include adipic acid, sebacic acid, maleic acid or its anhydride, azelaic acid, glutaric acid, etc. In this case, the amount used is equivalent to 50% of the total acid component.Next, these dicarboxylic acids are esterified with a polyol.

As a polyol, tris(2-hydroxyethyl)
Isocyanurate (THEIC) alone or in various ratios of THEIC with dihydric alcohols such as ethylene glycol, neopentyl glycol, propylene glycol, diethylene glycol, 1,3-hydroxyethyl, 5,5'-dimethylhydantoin, etc. Mention may be made of mixtures of. In place of all or part of THEIC, alcohols having at least 3 hydroxyl groups can be used, such alcohols including:
For example, glycerin, trimethylolpropane, 1,2,
Examples include 6-hexanetriol, bentaerythritol, trimethylolethane, and 3-methyl-1,3,5-hexanetriol.

Surprisingly, the products obtained using THEIC are better soluble in water than those obtained using glycerin. It is surprising that large molecules give products that are better soluble in water. This is because THEIC provides a product that is well soluble in water with the use of small amounts of co-solvents during product use. Based on all polyhydric alcohols,
10-90% of the total equivalent is provided by dihydric alcohol and the remainder by alcohol having at least 3 hydroxyl groups.

The preparation of the polyester-imide is not particularly limited and is not limited to a particular reaction order. It can be prepared by charging all the reaction components into a reactor and heating to 400-460°F to react. Other suitable preparation procedures include:
Preparation procedure in which the polyamine, aromatic acid anhydride and polyol are heated to complete the imidization step and then reacted with the addition of the aromatic dicarboxylic acid or its alkyl ester under appropriate reaction conditions to form the polyester component. There is. Although reactions to prepare polyester-imides are usually carried out in the absence of solvents, this does not preclude the use of solvents. In order to obtain a well-balanced appearance in terms of heat shock and finished product appearance, it is highly desirable to have a high proportion of diimide diacetate and a high proportion of hydroxyl. It has been discovered that polymers have been made to achieve these objectives. Regarding the content of the diimide diacid, it has already been explained that it is formed by the reaction of 1 mole of aromatic diamine with about 2 moles of aromatic acid anhydride.

The combination of molar contents of this product and the aromatic dicarboxylic acid mixture is then used to calculate the respective percentages (%). An example of this is shown below. ) Thus, on a mole % basis, the diimide diacid content is 50%.

Such calculations are used in the examples below to show both the mole percent diimide diacid and conventional acid and the mole percent p of the total reactants used in forming the polyester-imide base polymer. It has been adopted. 31) In the preparation of soil stills, in order to obtain good fluidity on the wire due to the formation of lower molecular weight polymers with low softening points,
It is preferable that the alcohol group (0H) is in excess with respect to the acid group (COOH).

This means that the 0H/ω0H ratio is 1.80/1 to 2.50.
/1. To put this in other words, in order to obtain good flow performance and other properties in wire, the 0H group is 80 to 150% lower than the COOH group.
% excess is required. Polyester-imide wire enamels contain organic titanates such as titanate chelates, their salts, alkyl titanates, etc. in an amount of 1 to 10% of the total solids in the enamel.
%, preferably 2 to 5%.

The addition of this type of adjuvant increases the temperature of the enamel. Representative examples of preferred organic titanates include the triethanolamine chelate of titanium known as "Tyza-TE" and the ammonium lactate salt of titanium known as "Tyza-LA".
These titanates and other hydrolytically stable titanates can be used as crosslinking agents. Organic alkyl titanates such as Tyza-TPT (tetraisopropyl titanate), Tyza-TBT (tetrabutyl titanate), tetrahexyl titanate, etc. are rapidly hydrolyzed in the presence of water, but they cannot be diluted in advance in a polar solvent. If it is pre-reacted with a prepolymer, it can then be dissolved in water and water without any problem.

Regarding this technique, Examples 8(b), 9(b), 1
1(b) and 12(b).
Solvents are not required in the preparation of the polyester-imide prepolymer.

Polar type solvents are used as co-solvents with distilled water in preparing aqueous solutions. Conventionally known cresylic acid/aromatic hydrocarbon (e.g. xylene) mixed solvents can also be used to make solvent-based wire enamels.
The solvent-based enamel exhibits similar performance to the water-soluble one. A performance comparison of solvent-based enamels versus water-based enamels using the same polymers is shown in Table 1 below. To solubilize these essentially water-insoluble resinous prepolymers in water, various amines are used that react with free carboxyl or amine acid groups to form water-soluble salts.

Examples of the amines include alkynoleamines, anolecanolamines, morpholine type amines, and the like. In general, tertiary amines are the ones that serve best in terms of fast curing and maximum moisture resistance and minimal moisture resistance of the baked film. For this reason, trialkylamine, N-alkyldiethanolamine, N,N-dianolequinoleanoleamine, N-alkylmorpholine, N-hydroxylalkylmorpholine, etc. are used. The alkyl group is usually a lower alkyl group having 1 to 4 carbon atoms. Representative examples of tertiary amines include triethylamine, trimethylamine, tributylamine, triethanolamine, and N,N-dimethylethanolamine (a preferred tertiary amine).

), N,N dimethylethanolamine, N,N-diisopropylethanolamine, N,N-butylethanolamine, triisopropanolamine, N-methyldiethanolamine (a preferred tertiary amine), N-
Ethyldiethanolamine, N-propyldiethanolamine, N-methylmorpholine, N-ethylmorpholine,
Examples include N-(2-hydroxyethyl)morpholine, 2-amino-2-methyl-1-propanol, and 2-dimethylamino-2-methyl-1-propanol. The amine lowers the pH of the aqueous solution to 7 to 9, preferably 7.
．． 5-8) Used in an amount sufficient to give a rating of 5. The combined use of a polar solvent as a minor component of the water/cosolvent blend improves the flow during curing of the enamel and ultimately improves the smoothness and unevenness of the baked film. .

If a polar solvent is used, its amount is preferably 10-25%. Typical polar solvents that can be used are primarily water-miscible, although cresylic acid is also used in optimal amounts. For example,
Glycol ethers such as N-methylpyrrolidone, butyrolactone, dimethyl sulfoxide, diacetone alcohol, dioxane, methoxyethanol, ethoxyethanol, butoxyethanol, diethylene glycol monomethyl ether, ethyl alcohol, isopropyl alcohol, methyl alcohol, ethylene glycol, diethylene glycol , alcohols such as triethylene glycol, trimethylene glycol, propylene glycol, dipropylene glycol, acetone, ketones such as methyl ethyl ketone, glycol ether acetates such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, diethylene glycol Glycol diethers such as dimethyl ether and di5 ethylene glycol diethyl ether can be mentioned. The co-vesting medium that can be used in combination with water is O~40% of the total amount of the blend, preferably 10~40% of the total amount of the blend.
25%, for example 20%. The IC result of the use of the low molecular weight prepolymers according to the invention is that the solids content of both water-soluble and solvent-based enamels is higher than the solids content in known solvent-based enamels. That is, the former has a solid content of 50 to 55%, while the latter has a solid content of 30 to 35%. Typical solids range is 40-6
5%, and the preferred range is 45-60%. The products of the invention are applied to wires by felt coating, dip coating, etc., similar to conventional wire enamel application methods. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 Electric stirrer, gas inlet tube, thermometer for flask and distillate head, 3-bagel cap, Snyd.
er) Reaction components A, B, C, D and E were charged into a 51 three-bottle flask equipped with a rectification column and a water-cooled condenser.

Replace the inside of the flask with dolphin and gradually raise the temperature to 450-460.
'F and held at the same temperature until the desired reaction product was obtained. The reaction was terminated when the viscosity measured as a 30% solids cresylic acid solution reached U1/4.

The melt was then transferred into a dish to form a solid form. b
Preparation of Water-Based Wire Enamel The hard solid resin was crushed into small pieces and 400 g of this polymer was mixed with N-methylpyrrolidone (hereinafter referred to as NMP).

) in a three-necked round bottom flask with 50g,
Until this polymer liquefies and dissolves ('250~
Heat to 270°F. distilled water and dimethylethanolamine (hereinafter referred to as
It's called DMEA.

) were carefully added to the flask. Furthermore, the viscosity is Z (according to a Cardner-Bolt viscometer).
Water, amine and solvent were added to prepare the trout, resulting in a pH of 7.5-8.5 and a solid content of 53.3%. Next, on a solids-to-solids basis, 4.5% of Tyza-TE
was added to the solution, viscosity Y1/4, PH8, solid content 54.1
% aqueous enamel was obtained. Example 2a Preparation of Polymer The polymer of this example was prepared using the same equipment and following a similar procedure as in Example 1(a).

The reaction was controlled so that the viscosity measured as a 30% solids cresylic acid solution was R1/2.

The melt was then transferred into a dish in solid form. b Preparation of aqueous wire enamel 500 g of the base polymer obtained in 2(a) above using the same equipment as in Example 1(b) and following the same procedure;
A water-based enamel was prepared by blending 62.5 g of NMP, 65 g of DMEA, 25 g of distilled water, and Tyza-TE.

The water-based enamel thus obtained has a viscosity of W1/2,
The pH was 8.35 and the solid content was 57.7%. Example 3a Preparation of Polymer The polymer of this example was prepared using the same equipment and following similar procedures as in Example 1(a).

The reactants were allowed to react until the melt became transparent and there was no more unreacted material. The viscosity, measured as a 30% solids cresylic acid solution, was U1/2.

The melt was then converted into solid form. b Preparation of aqueous wire enamel 500 g of the base polymer obtained in 3(a) above using the same equipment as in Example 1(b) and following the same procedure;
65 g of NMP, 65 g of DMEA, 252 g of distilled water, and 28. lg was blended.

An aqueous enamel with a viscosity of X3/4 and a solids content of 57.54% was obtained. Example 4a Preparation of polymer In preparing the polymer of this example, Example 1(a)
The same equipment was used and a similar procedure was adopted.

When the sample was in a 30% solids cresylic acid solution, it was allowed to react until clear, and then the melt was transferred to a dish for solid form. b Preparation of water-based wire enamel
, 500 g of the base polymer obtained in 4(a) above by the same procedure using the same equipment as in Example 1(b),
NMPl3Og, DMEA5Og and distilled water 520g
Blend, viscosity Y1/2 +, solid content 41.7%
A water-based enamel was prepared.

Example 5 a Preparation of polymer In this case, the same procedure as in Example 1(a) was used, and the procedure described above was adopted.

When the sample was in 30% cresylic acid solution, it was allowed to react until clear, and then the melt was transferred into a dish to form a solid form. b Preparation of aqueous wire enamel 500 g of the base polymer obtained in 5(a) above using the same equipment and following the same procedure as in Example 1(b)! : M
NP63g, DMEA8Og and Tyza-TE 28g
was added to prepare enamel.

The enamel had a viscosity of X3/4 and a solids content of 58.5%. Comparative Example a Preparation of Polymer In preparing the polymer of this comparative example, Example 1(a)
The same equipment was used and a similar procedure was adopted.

The reaction was controlled to a final viscosity of 13/4, measured as a 30% solids cresylic acid solution, and the melt was then transferred into a dish to form a solid form.

Preparation of solvent-type wire enamel Add 314 g of cresylic acid and petroleum naphtha (aromatic hydrocarbon) to 400 g of the base polymer obtained in the above ratio (a).
Add 186g and boil for 300 minutes until the polymer is completely dissolved.
Heated to °F.

The solution in the flask was then cooled to 160°F and 65 g of cresylic acid, 35 g of petroleum naphtha, 50 g of 40% solids creso)loop enol condensate, and 110 g of toluene diisocyanate trimer at 40% solids were added. ,
The solution was stirred until it became homogeneous. 18 g of TPT (tetraisopropyl titanate) was added at a temperature of 160°F. This batch was heated to 250°F and then heated to the same temperature for 2 hours.
After a period of time, a solvent-based wire enamel was prepared. The viscosity was G1/2 and the solid content was 40%. The solvent-borne wire enamel became cloudy after one week, but otherwise remained unchanged.

Example 6 a Preparation of Polymer The preparation method adopted in this example is as shown below:
Each reaction component is reacted in a specific order.

51 three-neck flasks equipped with an electric stirrer, gas inlet tube, Dean-Strap water trap with thermometer, and water-cooled condenser contained the reactants,
(B) and (O) were charged.

The inside of the flask was purged with nitrogen and the temperature was raised to 228°F.
At 228°F, reaction component (D) was added to the flask and the temperature was gradually increased to 320°F.

Distillation started at the same temperature. The reaction was continued until the entire amount of TMA had reacted. The temperature peaked at 410°F and 72 ml of water was collected as distillate. The batch was cooled to 338°F and reaction component (E) was added thereto. The temperature was gradually increased to 450° F. and held at that temperature until an additional 98 ml of distillate was collected and a drop of the molten sample as a pellet formed a clear hard pellet at room temperature. The batch was cooled to 320°F and reactant (g) was added thereto. The temperature was raised to 330°F and samples were taken periodically to measure the extent of reaction by viscosity increase.
When the viscosity of the resin sample reached T3/4+, cresylic acid was added to dilute it to 30% solids, and the contents of the flask were quickly poured into a metal gallon can and allowed to solidify. a Preparation of aqueous enamel Enamel 1 Using the same equipment as in Example 1(b) and following the same procedure, add 220 g of the base polymer obtained in 6(a) above, 110 g of butoxy alcohol, 11 g of DMEA, 440 g of distilled water, and the hydroxyl of diacetone acrylamide. Methylated derivative (hereinafter referred to as HMDAA).

) and 4.8 g of Tyza LA were added to prepare a water-based enamel. Its viscosity is X3/4, pH8. O,
The solid content was 28.7%.

Enamel 2 A water-based enamel was prepared using the same equipment as in Example 1(b) but following a different procedure as shown below.

600 g of butoxyethanol was added to 240 g of the base polymer obtained in 6(a) above and heated to 290° F. until the polymer was completely dissolved.

Next, 7.2 g of Tizer TPT (tetraisopropyl titanate) was added at 290°F, and then the temperature was raised to 320°F and maintained at the same temperature for 1 hour. 250 flask contents
50 g of butoxymethanol was added thereto and stirred until homogeneous. Then, 5 g of DMEAl and 440 g of distilled water were added and stirred until the solution became homogeneous and transparent to obtain a water-based enamel. Its viscosity is M1/4, PH
was 8.06, and the solid content was 29.56%. Example
7a Preparation of Polymer In preparing the polymer of this example, Example 6(a)
The same equipment was used and a similar procedure was adopted.

The reaction was controlled to have a final viscosity of R1/4, measured as a 30% solids cresylic acid solution.

The melt was then transferred into a dish to form a solid form. b. Preparation of water-based enamel Using the same equipment as in Example 1(b) and following the same procedure, 270 g of butoxyethanol was added to 640 g of the base polymer obtained in 7(a) above. 22 g of DMEA and 540 g of distilled water were added to prepare a water-based enamel without other additives.

Its viscosity is Q1/4, pH is 7.8, and solid content is 43.5.
It was %. Enamel 1 2 850g of the above enamel 1 and HMDAA2O. 8g
and 8 g of Tyza-LA were added as a hardening agent to obtain an enamel.

Its viscosity is Q1/4, pH is 7.8, and solid content is 42.
It was 2%. Example 8a Preparation of polymer In preparing the polymer of this example, Example 6(a)
The same equipment was used and a similar procedure was adopted.

The reaction was controlled to a final viscosity of V1/2+, measured as a 30% solids cresylic acid solution.

The melt was then transferred into a dish to form a solid form. b
Preparation of aqueous enamel 120 g of butoxyethanol was added to 480 g of the base polymer obtained in 8(a) above and heated to 290° F. until the polymer was completely dissolved.

Next, 28.8 g of Tyza TPT solution (50% butoxyethanol) was added dropwise over 65 minutes at 280°F.

The temperature was raised to 320°F and held at that temperature for 1 hour.

The contents of the flask were then cooled to 250°F, and 75 g of butoxyethanol was added and stirred until the solution was homogeneous. Add 33 g of DMEA and 8 g of distilled water to the resulting solution.
Aqueous enamel was prepared by adding 40 g and stirring until uniform.

The viscosity was M, the pH was 8.1, and the solid content was 30.4%. Example 9a Preparation of polymer In preparing the polymer of this example, Example 6(a)
The same equipment was used and a similar procedure was adopted.

The reaction was controlled to a final viscosity of V1/4+, measured as a 30% solids cresylic acid solution.

The melt was then transferred into a dish to form a solid form. The melting point of the hard resin was 79°C by the ring and ball method. b Preparation of aqueous enamel Aqueous enamel was prepared using the same equipment as in Example 1(b) but by a different procedure as shown below.

480 g of the base polymer obtained in 9(a) above was dried using butoxyethanol (preferably anhydrous CasO4).

2) until the polymer is completely dissolved.
Heat to 90°F.

Cool the batch to 200°F and incubate with a
g was added dropwise over 20 minutes. At 220'F, 50 g of butoxyethanol was added and the temperature was raised to 253°F within 10 minutes and held at that temperature for 2 hours.

The flask contents were then cooled to 170 F and the DME
A3Og and 200g of distilled water were added and stirred until the solution became homogeneous. Furthermore, enamel was prepared by adding 30 g of butoxyethanol and 655 g of distilled water, and the viscosity V
1/4, PH8. O5, solid content was 30.4%. Example 10a Preparation of Polymer In preparing the polymer of this example, Example 6(a)
Using the same equipment and following the same procedure as in 2L
The molten polymer was allowed to react until there were no unreacted solids, ie, it was clear with no particles present.

A total of 218 ml of distillate was collected. b. Preparation of aqueous enamel Unmodified enamel An enamel without additives, ie unmodified enamel, was prepared using the same equipment as in Example 1(b) and according to the following procedure.

67 g of butoxyethanol was added to 600 g of the base polymer obtained in 10(a) above and heated to 290° F. until the polymer was completely dissolved.

The temperature was lowered to 250°F and 30g of DMEA was added and mixed until the solution was clear. Next, 268 g of distilled water was added and stirred until the mixture became homogeneous. In addition, distilled water 4
80g, poxyethanol 120g and DMEA3
Prepare enamel by adding Og, viscosity W1/4, PH7
~8, solid content 37.8%, butoxyethanol content (total solvent blend) 20%. Enamel 11 Add HMD to 700g of unmodified enamel obtained in 10(b) above.
4.82 g of AAl and 48.8 g of Tyza LA were added and stirred until homogeneous to prepare an enamel.

Enamel has a viscosity of Y1/2+, a pH of 7.85, and a solid content of 3.
It was 8.8%. Enamel 2. Add HOA to 800g of unmodified enamel obtained in 10(b) above.
Enamel was prepared by adding 6.93 g of Al and 34.87 g of Tyza-TE and stirring until uniform.

The enamel has a viscosity of Q3/4, a pH of 8.4, and a solid content of 39.
It was 7%. Example 11a Preparation of Polymer GlycO Chemicals,
Inc. ) The product/chemical name is 1,3-bis(hydroxyethyl)-5,5″-diethylhydantoin.

In preparing the polymer of this example, Example 6 (a
A similar procedure was adopted using the same equipment as in ).
The reaction was controlled to a final viscosity of U3/4+, measured as a 30% solids cresylic acid solution, and the melt was then transferred into a dish to obtain solid form.

120 g of butoxyethanol was added to 480 g of the base polymer obtained in 11(a) above and heated to 290° F. until the polymer was completely dissolved.

Next, at 300°F, 28.8 g of Tyza-TPT solution (50% butoxyethanol) was added dropwise to the flask over 85 minutes. Thereafter, 10 g of butoxyethanol was immediately added and the flask contents were held at 300'F for 90 minutes. At a temperature of 180°F, 25 g of DMEA and 200 g of distilled water were added and stirred until the solution was homogeneous.

Enamel is very viscous, so butoxyethanol 42
g and 500 g of distilled water to adjust the viscosity
+, PH8. 1, and the solid content was 34.3%. Example 1
2a Preparation of polymer In preparing the polymer of this example, Example 6(a)
A similar procedure was adopted using the same equipment as in .

Final viscosity in 30% solids cresylic acid solution is U3
The reaction was controlled so that the reaction temperature was 1/4, and then transferred to a metal can for solidification.

b. Preparation of aqueous enamel 120 g of butoxyethanol was added to 480 g of the base polymer obtained in 12(a) above and heated to 290° F. until the polymer was completely dissolved.

Next, at 290°F, the Tizer-TPT solution (5
28.8 g of 0% butoxy-ethanol was added dropwise to the flask over 50 minutes and stirred until the composition became uniform. Thereafter, 40 g of butoxyethanol was added at once and the flask contents were held at 300° F. for 1 hour. Cool the batch to 135°F and add 30 g of DMEA and 66 g of distilled water.
0 g was added and stirred until the solution became homogeneous to obtain enamel. Its viscosity is U3/4, pH 7.8, solid content 35.3
It was %.

Example 13a Preparation of polymer In preparing the polymer of this example, Example 6(a)
A similar procedure was adopted using the same equipment as in .

Final viscosity in 30% solids cresylic acid solution is V1
Write the reaction so that it is /4+. The melt was then transferred to a metal can for solidification.

b. Preparation of aqueous wire enamel 50 g of N-methylpyrrolidone was added to 200 g of the base polymer obtained in 13(a) above and heated to 270°C. The polymer was dissolved.

The batch was cooled to 200°F and DMEA1Og and 150g of distilled water were added. After stirring for 1 hour, the enamel was very viscous, so 325g of distilled water was added. 50 g of N-methylpyrrolidone, 7 g of DMEA and TELO
g was added to adjust the viscosity to H1/2, pH to 7.9, and solid content to 25.93%.

To demonstrate the excellent electrical performance of these water-based enamels,
A few were selected from those shown in each example and compared with the electrical performance of solvent-borne enamels using the same base polymer.

The results are shown in Table 1. In fact, the overall performance of the aqueous enamel according to the invention is highly desirable. The solvent used in the solvent enamel in Table 1 consists of 65% cresylic acid and 35% aromatic naphtha. The enamel was applied to the wire at room temperature and then baked at 800°F according to conventional methods.

Claims (1)

[Claims] 1 Molecular weight of 600 to 1300, 1.8:1 to 2.5:
an OH to COOH ratio of 1 and 5 to 60% polyimide based on the total weight of polyimide and polyester;
The alcohol of the polyester is a water-soluble thermosetting polyester prepared by reacting an initial polyester-imide prepolymer containing an alcohol having at least three hydroxyl groups with a tertiary amine.
A coated conductor made of an imide prepolymer composition on the surface of the conductor. 2. The coated conductor according to claim 1, wherein the composition is suitable for use as a wire enamel after being dissolved in water. 3. The coated conductor according to claim 2, wherein the composition contains a water-soluble titanate curing agent. 4. The coated conductor according to claim 3, wherein the polyimide in the composition contains a reaction product of an aromatic diamine and an aromatic tricarboxylic acid monoanhydride. 5. The coated conductor according to claim 4, wherein the aromatic tricarboxylic acid anhydride is trimellitic anhydride. 6 The alcohol of the polyester in the composition is Tris (2
6. The coated conductor according to claim 5, comprising: -hydroxyethyl) isocyanurate. 7. The coated conductor according to claim 6, wherein the polyester acid in the composition contains terephthalic acid or isophthalic acid. 8. The coated conductor according to claim 7, wherein the polyester acid in the composition contains terephthalic acid. 9. The coated conductor according to claim 8, wherein the acid of the polyester in the composition contains diimide dicarboxylic acid, and the imide group has a five-membered imide ring. 10. The coated conductor according to claim 9, wherein the polyimide is an imide of 2 moles of trimellitic anhydride and 1 mole of oxydianiline or methylene dianiline. 11 The polyimide in the composition is 35 to 55% of the total amount of polyimide and polyester.
The coated conductor according to item 0. 12. The coated conductor of claim 11, wherein the 12OH to COOH ratio is between 2.20 and 2.50:1. 13. The coated conductor of claim 12, comprising a titanate curing agent for the polyester in the composition. 14 Claim 13, wherein the titanate is water-soluble
The coated conductor described in section. 15 conductor, molecular weight of 600 to 1300, 1.8:
having an OH to COOH ratio of 1 to 2.5:1 and a polyimide content of 5 to 60% based on the combined weight of polyimide and polyester, the alcohol of the polyester containing an alcohol having at least 3 hydroxyl groups; coating the electrical conductor by passing an initial polyester-imide prepolymer consisting of a water-soluble thermosetting polyester-imide prepolymer composition prepared by reacting with a tertiary amine. Method for manufacturing coated conductor. 16. The method according to claim 15, wherein the composition is dissolved in water and suitable for use as a wire enamel. 17. The method of claim 16, wherein the composition comprises a water-soluble titanate curing agent. 18. The method according to claim 17, wherein the polyimide in the composition contains a reaction product of an aromatic diamine and an aromatic tricarboxylic acid monoanhydride. 19. The method according to claim 18, wherein the aromatic tricarboxylic acid monoanhydride is trimellitic anhydride. 20. The method according to claim 18, wherein the polyester alcohol contains tris(2-hydroxyethyl)isocyanurate. 21. The method according to claim 20, wherein the polyester acid contains terephthalic acid or isophthalic acid. 22. The method according to claim 21, wherein the polyester acid contains terephthalic acid. 23. The method according to claim 22, wherein the acid of the polyester in the composition contains diimide dicarboxylic acid, and the imide group has a five-membered imide ring. 24. The method according to claim 23, wherein the polyimide is an imide of 2 moles of trimellitic anhydride and 1 mole of oxydianiline or methylene dianiline. 25. The method of claim 24, wherein the polyimide is 35 to 55% of the total amount of polyimide and polyester. 26. The method of claim 25, wherein the 26OH to COOH ratio is between 2.20 and 2.50:1. 27. The method of claim 26, comprising a titanate curing agent for polyester. 28 Claim 27 that the titanate is water-soluble
The method described in section.