JPS63191855A - Polyester coating composition based on solid terephthalate polyester and production thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to employing polymeric terephthalate polyester plastics in solvent solutions to provide FB vehicle solutions and aqueous dispersion coating compositions.

BACKGROUND TECHNOLOGY Dimethyl terephthalate polyester plastics are known, and a polymer with excellent strength and physical toughness can be obtained, and its polymer insolubility properties are used to mold it into bottles for general use. These polyesters are manufactured from ethylene glycol as is well known. However, these insoluble thermoplastic materials are too hard to be recycled and are often discarded without being reused, creating difficult processing problems.

Although it is desirable to dissolve these terephthalate polyesters in organic solvents so that they can be used as solvent solution coating compositions,
This is not practical. Heating the terephthalate polyester in a strong solvent will cause the terephthalate polyester to dissolve, but these polymeric polyesters are crystalline and therefore, when the solution is cooled to room temperature, the polyester will crystallize out of the solution.

Despite these difficulties, polymeric dimethyl terephthalate solid polyester (manufactured by reacting dimethyl terephthalate with ethylene glycol) is an inexpensive source of synthetic resins with high strength and physical toughness; It is desirable to replace polyesters with solvent solutions and useful aqueous coating compositions. US Patent No. 4
．． 546,. These polyesters can be pre-digested or transesterified to introduce hydroxy functionality that can co-react with organic polyisocyanates, as described in the documents mentioned in No. 169 and Kaimei M. The required solvent solubility cannot be obtained by coating from an organic solvent solution. Also, these same solvent-soluble resins cannot be coated as aqueous dispersions, thereby using aqueous systems containing smaller amounts of organic solvents.

DISCLOSURE OF THE INVENTION According to the present invention, a polymeric dimethyl terephthalate solid polyester is prepared by: 1. having a molecule M within the range of Coo to 10.000 is incorporated into a hot melt of a droxy-functional linear polyester to form a melt mixture containing from about 20% to about 55%, preferably from 25% to 50%, of said terephthalate polyester. 2-ethoxydiethylene glycol acetate, and this mixture was mixed with a sample of 2-ethoxydiethylene glycol acetate.
0% mixture as a clear to slightly cloudy solution is determined to have formed, then this reacted hot melt is mixed with an organic solvent to form a solution of the reacted hot melt in the solvent. Provided is a method for producing a solvent solution stable at room temperature from the polymeric dimethyl terephthacyl-solid polyester, characterized in that the solution is stable and even when cooled to room temperature, it is essential as a commercial product. stability is maintained.

A hot melt mixture of a terephthalate polyester and a linear hydroxy-functional polyester gradually reacts by transesterification by transferring some methyl terephthalate groups to some terminal hydroxyl groups of the low molecular weight polyester to form a terephthalate polyester. It is thought that hydroxyl groups are generated and in this way the two types of polyesters are made compatible with each other. When the reaction has progressed to the point that the two polyesters are compatible with each other as shown by solution clarity tests, the mixture of polyesters can be dissolved in the organic solvent and the container can be cooled with water. , a stable solution is obtained at room temperature. Additionally, this mixture of polyesters can be utilized as an aqueous coating dispersion after dissolving in a water-miscible solvent.

Although the desired transesterification reaction proceeds slowly in the hot melt, it is appropriate to use temperatures above about 200°C, with a temperature of 230°C being typical. Although this reaction proceeds without any catalyst, it is appropriate to include a catalyst such as dibutyltin oxide to accelerate the reaction.

Suitably, the organic solvent is added to the reacted hot melt while the hot melt is still hot, suitably at about 170°C. The dissolved solution is stable even at air temperature.

Preferred organic solvents are transesterification media, especially ether-
It is an ester solvent. Preference is therefore given to using 2-ethoxydiethanol glycol acetate or the corresponding propionate or butyrate. However, the corresponding 2-butoxy ethers and other similar ether esters can also be used, exemplified by 2-butoxyshetanol acetate and propylene glycol methyl ether acetate. DuPont's product Dibasic Ester (Dibasi) is a mixture of dimethyl esters of glutaric acid, azelaic acid and succinic acid.
c Ester ) is also useful. Although these solvents are preferred, inert volatile organic solvents, especially those with higher boiling points useful for hot melt dissolution, are known and widely available for use. Also included are water-insoluble solvents such as toluene and xylene.

These solutions contain therein an aminoplast resin such as hexamethoxymethylmelamine (such as the product Cymel 303 of American Cyanamid Company), which is suitable for reacting with the hydroxyl functionality described above. A thermosetting solvent solution coating composition comprising the above-described solvent solution product dissolved in a solvent. however,
Also phenoplast resins exemplified by phenol-formaldehyde condensates and ethylhexanol2
Blocked polyisocyanates can also be used, exemplified by inphorone diisocyanate, which is used to react with moles to form diurethanes.

All these curing agents are known for curing hydroxy-functional polymers.

Particularly useful solutions for thermoset coatings include from about 50% to about 65%
of! ! Although the resin solids content is relatively high within the range, larger amounts of solvent can be used if desired.

It may also contain dispersing additives used.

Curing agents are used in conventional proportions, but these range from 3% to 45%, preferably from 10% to 30%, per total resin solid valve.
It is.

According to yet another aspect of the invention, a solution of the above-described compatible mixture of polyesters is dispersed in water using an epoxy phosphate dispersed by salt formation in the aqueous medium.

Although water-miscible '4ia solvents are present in the aqueous dispersion, it is preferred that these solvents be kept to a minimum. The molten IIA solution used to form the aqueous dispersions of the present invention contains from about 35% to about 75%, preferably from 50% to about 75% of the resin solids.
It is 70%.

The hydroxy-functional linear polyesters useful in the present invention have a deO-oxy value of at least about 20 and an acid value of about 30.
preferably less than about 15 and a hydroxyl number of 30 to 150, more preferably 35 to 75. These linear polyesters are known per se and are prepared by simply polyesterifying dihydric alcohols with dibasic carboxylic acids, as is amply illustrated in the examples.

When an organic solvent is used to promote water dispersibility, it is appropriate to add this solvent to the reacted hot melt as described above.

Compatible polyester compounds and those containing a portion of added solvent cannot themselves be stably dispersed in water. However, it has been found in accordance with the present invention that these mixtures are capable of stably dispersing the epoxy phosphate in the water dispersed therein.

Any epoxy phosphate that can be dispersed in water with a volatile base, usually an amine (preferably ammonia) can be used. Water-miscible organic solvents can be used to facilitate dissolution;
However, this may be the same or different solvent used to dissolve the polyester mixture, or the polyester mixture solution? W* allows avoiding the addition of more organic solvents to promote dispersion of the epoxy bosphate.

Epoxy phosphates useful in the present invention include:
The oxirane content of the polyepoxide is at least 0.
Preference is given to resinous polyepoxides reacted with 0.5 mol of orthophosphoric acid (its anhydride which gives orthophosphoric acid when water is added).

The preferred proportion of orthophosphoric acid is 0 per oxirane.
．． 1 mol to 0.7 mol, more preferably ω per oxirane
The amount is 0.1 mol to 0.5 mol per unit. Although phosphoric acid is theoretically trivalent, under the mild conditions of the reaction used in the present invention (which itself is prior art), the 3i P-O
Only one of the HMs reacts, leaving the other 211 P-OH bases available for salt formation with volatile amines.

To provide a stable dispersion, any unreacted oxirane functionality of the polyepoxide is preferably consumed by hydrolysis with water. An alternative method of consuming unreacted oxirane functionality is by reaction with alcohol or other methods known in the art.

Volatile amines used for neutralization are known, and dimethylethanolamine is preferred in the present invention, as specifically shown in the examples. Even ammonia is considered a volatile amine. This is because it is known to form water-dispersible salts with resinous M-bamboo materials.

The polyepoxide used in the present invention can be constituted by any resinous epoxide having a 1°2-epoxy weight of greater than 1.2, preferably from 1.4 to 2.0. Diglycidyl ethers of bisphenols, such as bisphenol A, having an average molecular weight in the range of 350 to 7,000 are desirable, with an average molecular weight of at least 800 being preferred.

In order to provide the necessary heat resistance to the coating of sanitary cans, 15
A molecular layer greater than 00 is required. shell chemical
Epon 100113 and Epon 1004 from the Company are preferred. The best is used for heat and temperature resistance.

A preferred preparation of epoxy phosphate is aZ7s
No. 4,598,109, co-owned by RaJ 5hah and RaJ 5hah.

The polyester mixture is dispersed in an aqueous solution of epoxy phosphate using a layering of polyester solids to epoxy phosphate solids of 1:10 to 2:1, preferably 1:5 to 1:1.

These aqueous dispersions contain therein a curing agent suitable for reaction with the hydroxy functionality, usually an aminoblast resin such as hexamethoxymethylmelamine (such as the product Cymcl 303 from American Cyanamid Company). It is useful in thermosetting coating compositions containing the aqueous dispersions described above dissolved or dispersed in the composition. However, phenoplast resins exemplified by phenol-formaldehyde condensates and ethylhexanol2
Blocked polyisocyanates can also be used, exemplified by isophorone diisocyanate, which reacts with molar proportions to form diurethanes. All of these curing agents are known for curing hydroxy-functional monomers.

Apparently, the polyester mixture is hydroxy-functional and the epoxy phosphate is hydroxy-functional, so both are reactive with the curing agent during curing. This curing is accomplished using high temperatures, typically at temperatures of at least about 300''F, as is known.

The aqueous dispersions used to provide thermoset coatings in this invention may be clear or pigmented and can be applied by brush, roller or spray if desired. Special purpose dispersing additives such as waxes and flow modifiers may also be present.

The curing agents are used in conventional proportions, these proportions being from 3% to 45% curing agent per total resin solid valve, preferably from 10% to
It is 30%. Acid catalysts can be added to accelerate curing as is known.

The present invention is illustrated by the following preferred examples, in which all proportions in Motokawa's book and claims are expressed in terms of mff1 and unless otherwise specified, molecular weights are number average.

Miura example 1 2000ml! 159.18 g of diethylene glycol and 45 g of 1,4-butanediol were placed in a four-necked flask.
Weigh out 06g. The flask was equipped with a mechanical stirrer, a thermometer, a nitrogen inlet line and a 3-bubble Snyder column which was also connected to a Dean-Stark trap and a reflux condenser.

The contents of the flask were then warmed to 60°C, at which point 258.42 g of isophthalic acid, 56.85 g of adipic acid
g and 0.75 g of dibutyltin oxide catalyst are added.

The flask contents are then heated to reflux and the water is then collected in a Dean-Stark trap.

Reflux is continued until III lti is less than 20 ηKO)I/g. At this point, the flask is cooled and the Snyder column is removed.

The contents of the flask are then reheated to reflux at about 220°C, and the water is then recaptured until an acid number of 10 KOI-1/l is reached to form a linear hydroxyl with a hydroxyl number of 40-50. A functionalized polyester is obtained. In total,
Approximately 659% of water is collected.

When the final acid number is reached, Odar PE
Beret 346. of Ding G6763 (polymeric crystalline dimethyl terephthalate solid polyester with ethylene glycol supplied by Eastman Botak Company).
Add 34 g and 0103 g dibutyltin oxide.

The mixture is then heated to 230°C to melt the pellets. The temperature is maintained at 230° C. until a constant reduced viscosity (in a 50% solids solution in 2-ethoxydiethanol glycol acetate) is obtained at the approximate X-Y of the Gardner Foam standard comparison. The decrease in solution clarity at this point should clear the sample, but the sample subsequently becomes somewhat cloudy, producing a slightly cloudy solution when incubated overnight.

If these solution properties are reached, the melted am.
Cool to 90° C. and then slowly add 532.50 g of 2-ethoxydiethanol glycol acetate to form a solution. This solution has a resin solids content of 59.0%, an acid value of 15.22 ay KOH/g resin, a Gardner-Holdt bubble viscosity of z4, and a Gardner color of 6-7 (slightly cloudy). The solution is allowed to cool and then poured from the flask before it becomes too viscous to pour out.

Example 2 The experiment described in Flow Side 1 is exactly reproduced except for the raw material of polyester plastic. In this case, 346.34 pieces of plastic separated from a recycled clear soda bottle
57 was used. At this point, the plastic was melted into the droxy-functional polyester with heat at 245° C. and then maintained at a constant reduced viscosity XY at 50% solids in 2-ethoxydiethanol glycol acetate.

Furthermore, it was diluted with 2-ethoxydiethanol glycol acetate to obtain a finished product having the following solution tolerance. Non-volatile 81 fat solids content 58.15%, acid value 15.
44qKOH/9 polishing resin, Gardner bubble viscosity 2-25
and Gardner Color 13-14 (slightly cloudy).

327.91 g of diethylene glycol and 90 g of 1,4-butanediol were placed in a 3000 m four-bottle flask.
．． Weigh out 12g. The flask was then fitted with a mechanical stirrer, a thermometer, a nitrogen inlet line and a Digi-Stark trap and a reflux condenser.
Equipped with bubble slider column. The flask contents are heated at 60° C. under a nitrogen atmosphere and then 516.8/l of isophthalic acid, 113.70 g of adipic acid and 2.0 g of dibutyltin oxide are added. Acid value is 20It
The material is heated to reflux and water is collected in a trap until less than gKOH/g is reached.

At this point, remove the slider column and then reduce the acid value to 6.
■ Reheat the product to reflux and collect more water until less than KOH/g is reached.

In total, we caught 135g of main fishing.

At this point, Kodar PETG6763 Polyester 6
Add 99.05 g and 0.05 g dibutyltin oxide. The mixture was heated to 230° C. and then reduced to a constant reducing solution viscosity of Z −73 at 50% solids in a dibasic ester solvent (DIE supplied by DuPont).
Maintain this temperature until the temperature is reached. Again, the test sample is clear, but some crystallization occurs during the night, creating a slight haze.

The reaction is stopped by cooling to 190°C, adding the dibasic ester solvent 1075SF described above, then further cooling to 60'C before pouring the product out of the flask. The final solution properties are as follows. Non-volatile resin solids 57.06%, Gardner bubble viscosity Z -76 and Gardner color 9-10 (slightly hazy)
.

Example 4 In a 2000-meter four-bottle flask were added diethylene glycol 238.759, polyoxytetramethylene glycol [Teracol from DuPont].
650] 160 g, isophthalic acid 311.25 g, adipine 168.50 g and diptyltin oxide 0.9
0! Weigh out the iF. The flask is then equipped with a mechanical stirrer, a thermometer, a nitrogen population line and a 3-bubble Snyder column connected to a Diesi-Stark trap and a running cold water condenser. The flask contents are heated to reflux at 170'C under a nitrogen atmosphere, and water is then continuously collected. Heating is continued until the acid value reaches less than 20ayKO)-1/g. At this point, the column is removed and the molten resin is then reheated to reflux to bring the acid number below 11. In total, we caught 85g of main fishing. When this step of the reaction is complete, Kodal PETG6763
518.5g polyester and 0 dibutyltin oxide
．． Add 037.

The mixture is then heated to 230°C and then reduced to a constant reduced viscosity Y-Z at 50% in dibasic ester solvent.
Keep at this temperature until . At this point the test sample is clear. The reaction is completed by cooling to 190° C. and then adding 703L:i of bifA basic ester solvent. The solution was poured out of the flask at 60°C.

It has the following properties. Non-volatile resin solid content 63.
40%, 11lii 8.85ay KOH/g resin, Gardner bubble viscosity 75-z6 and Gardner color 5
-6 (slightly cloudy).

Example 5 Adipic acid 86.63 was added to a 2000 d four-neck flask.
g, isophthalic acid 296.18 g, diethylene glycol 239. OOg, polycaprolactone diol PCP
-0200 (Union Carbide) 131. Weigh out 0.0g and 0.9Cg of dibutyltin oxide. The flask is then equipped with a mechanical stirrer, a thermometer, a nitrogen inlet line and a 3-bubble Snyder column connected to a Diesi-Stark trap and a 'Jt flow-cooled IA vessel.

The contents of the flask are gradually heated to reflux at 190° C. under a nitrogen atmosphere, and the water is then collected in a trap. Continue heating until <111i20ayKo) l/g is reached, at which point the column is removed. Acid value 12a! FKOH
The molten mass is further heated until it reaches less than /g. In total, we caught 85 SF fishing rods.

In this regard, Kodar PETG6763 Polyester 50
Add 1.87 g and 0.039 dibutyltin oxide. The material was heated to 230°C and then reduced to a constant reduced viscosity of 2-2 at 50% solids in dibasic ester solvent.
Keep it until it reaches 1. - At this point the test sample is transparent. The reaction is stopped by cooling to 190° C. and then adding 780, (l) of dibasic ester solvent.

The finished product has the following solution properties: Nonvolatile resin solids 59.48%, acid number 9.4319 KOH/g resin, Gardner foam viscosity 74-Z5 and Gardner color 7-8 (slightly hazy).

Example 6 A white pigmented paste is prepared in the following manner.

In a 400 m stainless steel beaker, weigh 118.39 l of the solution product of Example 4 and 75 l of rutile titanium dioxide (R-900 supplied by DuPont). Stir at high speed until 72.9 g of 5C-100 solvent (commercial mixture of aromatic hydrocarbons) is added at this point.

Next, a sample of 133.1 g of the paste was passed through Nakyu 7 (
Nacure) 1051 (Corrosion resistance '14> 1.4g
hexamethoxymethylmelamine (Cymel 303 supplied by American Cyanamid Company) in a mixture with
) 12.59 to produce a white pigmented thermosetting solvent solution coating composition.

The paint was drawn onto a steel panel using a #28 wire-wound rod and placed in an oven temperature of 580°C for 35 minutes.
Bake for a second to harden the coating.

The cured coating produced as described above had the following properties. MEK O #1 Friction greater than 100, Pencil hardness F ~
1”, gloss greater than 80 and flexible 1T bend without cracking or big-off.

Another white paint is produced from another resin sample. 400al
! A stainless steel beaker of Example 5 hl et al. polyester 126.09J and rutile titanium dioxide (R-900) 75. Weigh out Og. The mixture is stirred at high speed until smooth and homogeneous, at which point 65.1 g of 5C-150 solvent is added.

A sample of the paste (133.1 g) was then mixed with Cymale 3031 containing 1.4 g of Nacure 1051.
Dropped in 2.59.

The white paint is applied to the steel panel using a #28 wire rod and the panel is then baked in an oven temperature of 580 for 35 seconds.

The cured white coating resists more than 100 MEK buffing and has a pencil hardness H1 gloss of 88 and a flexible OT bend with no cracking or big-off.

As can be seen, commercially available, crystalline and solvent insoluble polymeric dimethyl terephthalate polyesters are incorporated into solution coating compositions which cure to excellent properties.

318 g of diethylene glycol and 90 g of 1,4-butanediol were weighed into a 5,000-inch four-hole flask. The flask is then equipped with a mechanical stirrer, a thermometer, a nitrogen inlet line and a three-bubble Snyder force ram fitted with a Dean-Stark trap and a reflux condenser.

The flask contents are heated to 60° C. under a nitrogen atmosphere and then 507 g of inphthalic acid, 8.1129 g of adipine and 1.5 g of dibutyltin oxide are added.

The material is heated to reflux under a nitrogen atmosphere to collect water in a trap until an acid number of less than 20 jy KOH/g is reached.

At this point, remove the Snyder power ram, then the acid value 10j
The product is reheated to reflux until less than 19 KOH/g is reached to collect more water. In total, 135 fishing rods
Collect 9.

At this point, the product is cooled to 180° C. and then Kodal PETG 6763 Polyester 685.0 OSF and 0.05 g of dibutyltin oxide are slowly added to homogeneously dissolve.

Next (X-heat this mixture to 230 °C and then
This temperature is maintained until a constant reduced solution viscosity of R-8 is reached at 50% solids in Dowanol BC-300 (from The Dow Chemical Company). Again the test sample is clear, but - some slow crystallization occurs at night, creating a slight haze.

The reaction is terminated by cooling to 190°C, adding 1420 ml of 2-ethoxydiethanol glycol acetate, and then cooling to 60°C before pouring the product from the flask. The product has a resin solids content of 58.5
0%, Gardner-Holdt bubble viscosity 2-22, acid a19
．． 2qKOH/g resin Main resin - donor color 7-8
(slightly cloudy).

Example 9 Epoxy phosphate was produced using a 5000 d four-loaf flask equipped with a mechanical stirrer, thermometer, nitrogen inlet line, and reflux condenser. In this flask, 2-
Butoxethanol 1092g, orthophosphoric acid 47.3g
Weigh out 639 g of deionized water and 639 g of deionized water. The flask contents are then heated to 105° C. under a nitrogen atmosphere.

This heated solution is then added with an average molecular weight of about 2000.
Add 2098 g of diglycidyl ether of bisphenol A (Epon 1004 can be used). 10
Leave to rest for 30 minutes at 5° C. and add in small portions and increasing amounts with rapid stirring. Once the addition is complete, maintain the temperature of the mixture at 105° C. for 2 hours. then 2
An additional 400 g of -buto-1-ethanol is added, then the mixture is cooled to 60° C. and poured into a suitable container. The solution contains 61.3% non-volatile resin solids, and the solution has a Gardner bubble viscosity of z-77, a Gardner color index of 2 to 3, and an acid value of 20.111 g KOH/g resin as in Reference Example 9. Using the same equipment, add 2-
Butoxethanol 13209, orthorin 194.4
g and 130 g of deionized water. The flask contents are then heated to 95° C. under a nitrogen atmosphere.

This heated solution is then added with an average molecular weight of about 1000
Add 2100 g of diglycidyl ether of bisphenol A (Epon 100IF can be used). 1
Leave to rest for 30 minutes at 05°C, stir rapidly, and add in small portions in increasing amounts. Once the addition is complete, maintain the temperature of the mixture at 95° C. for 3 hours. Then 2-
Add 4809 additional butoxethanol and then cool the mixture to 60° C. and then pour into a suitable container.

This solution contains 56.7% non-volatile resin solids, the solution has a Gardner bubble viscosity of 2-2, a Gardner
Color index 3-5 and acid ++l 136.4ηKOH/
g resin.

Example 10 A number of aqueous coating compositions were prepared using the following general procedure.

Weigh the polyester and epoxy phosphate along with the appropriate crosslinking agent into an appropriately sized stainless steel beaker. The mixture is then stirred with a high shear disperser at low speed to ensure a homogeneous mixture. The desired amount of amine salt former is then added and then stirred until homogeneous. The stirring speed is then increased to high speed and water is then added gradually and in small increasing portions to prevent precipitation. Continue stirring at high speed until a reversal occurs as evidenced by a dramatic decrease in viscosity. Then use low speed stirring until all remaining water is added. In this regard, curing catalysts, flow modifiers,
Other materials such as wax lubricants may also be added.

The water-based paint is then allowed to stand for about 21 to 3 hours to allow any trapped air to escape. The paint is then applied to thick walled untreated aluminum foil using a sequential 6 wire wound rod. The coated foil is then heated in an oven held below 400 ℃ for 30 seconds and the cured film is then subjected to various tests. It can be seen that the cured coating has excellent methyl ethyl ketone resistance and is both tough and flexible. However, paints prepared with -Ji polymeric epoxy resin water are significantly superior in that they have even better hot water resistance.

Heat resistance is measured by deforming the cured foil using a Tinius-Olsen impact tester that places a small protrusion on the coated foil. The deformed substrate above is placed in boiling water for 30 minutes, and the degree of fogging is observed on the deformed portion of the film.

Also, attach adhesive tape to the deformed part of the film,
Next, observe the big off. The results are as follows.

Nosu CI') spoon The combination shows bad results in each case.

Therefore, while all combinations provide very useful coatings, the coating with the higher molecular weight epoxy resin of Example 9 provides excellent heat resistance properties that are unique and suitable for sanitary can coatings. In the above table, Cymel 30 supplied by American Cyanamid Company
3 is hexamethoxymethylmelamine. DMEA stands for dimethylethanolamine neutralizing agent, and MEK
Thick rubs are the number of back and forth rubs with the methyl ethyl ketone saturated cloth required to remove the coating from the substrate.

Claims (11)

[Claims] (1) incorporating a polymeric ethylene glycol dimethyl terephthalate solid polyester into a hot melt of a hydroxy-functional linear polyester having a hydroxy value of at least about 20 and an acid number less than about 30 and a molecular weight within the range of 1,000 to 10,000; forming a molten mixture containing from about 20% to about 55% of the terephthalate polyester;
-50 with ethoxydiethanol glycol acetate
% mixture as a hot melt until it forms a clear to slightly cloudy solution, and then the reacted hot melt is mixed with an organic solvent to form a solution of said solvent in said hot melt. Method for producing a room temperature stable solvent solution from the molecule ethylene glycol dimethyl terephthalate solid polyester. (2) the molten mixture contains 25% to 50% of the ethylene glycol terephthalate polyester;
and the hydroxy-functional linear polyester has an acid number of less than about 20 and a hydroxyl number of 30 to 150.
A method according to claim 1. 3. The method of claim 2, wherein the hydroxy-functional linear polyester has an acid number of less than about 10 and a hydroxyl number of 35 to 75. (4) A product produced by the method according to claim 1. (5) The product of claim 4, wherein the organic solvent is 2-ethoxydiethanol glycol acetate. (6) A thermosetting solvent solution coating composition comprising the solvent solution product of claim 4 having dissolved therein a curing agent suitable for reaction with the hydroxy functionality. (7) dispersing therein a salt of an epoxy phosphate with a volatile base and a high molecular weight ethylene glycol dimethyl terephthalate solid polyester with a hydroxy value of at least about 20, an acid number of less than about 30 and a
0,000 to form a molten mixture containing from about 20% to about 55% of the terephthalate polyester; The sample was kept as a hot melt until it formed a clear to slightly cloudy solution in a 50% mixture with 2-ethoxydiethanol glycol acetate, and then the reacted hot melt was mixed with a water-miscible organic solvent to reduce the solids content. a room temperature stable solvent solution prepared by forming a solution of the hot melt in the solvent having from about 35% to about 75% water stably dispersed therein; An aqueous coating composition. (8) The aqueous coating composition of claim 7, wherein the ratio of polyester solids to epoxy phosphate solids is from 1:10 to 2:1. (9) the molten mixture contains 25% to 50% of the ethylene glycol terephthalate polyester;
The solution of the hot melt in the solvent has a solids content of 50
% to 70%, and wherein said hydroxy-functional linear polyester has an acid number of less than about 20 and a hydroxyl number of less than about 30.
9. The aqueous coating composition of claim 8, having a molecular weight of 150 to 150. (10) The ratio of polyester solids to epoxy phosphate solids is 1:5 to 1:1, and the epoxy phosphate contains 0.1 mol to 0.5 mol orthophosphoric acid per equivalent of oxirane, and 10. The aqueous coating composition of claim 9, wherein the remainder of the oxirane functionality of the epoxy phosphate is hydrolyzed with water. (11) A thermosetting aqueous coating composition comprising the aqueous coating composition of claim 1 in admixture with a curing agent suitable for reaction with hydroxy functionality.