US2564129A

US2564129A - Cleaning and renewing used paint

Info

Publication number: US2564129A
Authority: US
Publication date: 1951-08-14
Anticipated expiration: 1968-08-14

Description

Patented Aug. 14, 1951 OFFICE CLEANING AND RENEWING USED PAINT BRUSHES Luigi Rotelli, Framingham, Mass., assignor to Selma M. Rotelli, Framin ham, Mass.

No Drawing. Application September 16, 1947, Serial No. 774,419

This invention relates to paint brushes and more particularly to cleaning and renewing paint brushes and has for its object the provision of an improved method of, and cleaning agent for, cleaning and renewing of used paintbrushes.

Another object is to provide a safe, effective and economically practical paint solvent and disintegrating agent for use in the cleaning and renewing of used paint brushes.

Still another object is to provide an effective paint brush cleaner and renewer.

Other objects will be apparent as the invention is more fully hereinafter disclosed.

In accordance with these objects, I have discovered that the water soluble salts of amino polyacetic acids, in warm to hot aqueous solutions, are safe, efiective and economically practical agents for use in the removal of dried paint residues in used paint brushes, when used alone or in association or combination with wetting agents or soap and detergent compounds or in association or combination with said wetting agents and soap and detergent combinations.

By the term amino polyacetic acid I mean to identify that group of amino polycarboxylic acids of which the following are typical examples:

tricarboxylic acid By the term water soluble salts of these said acids I'mean to identify the alkali metal, ammonia and substituted ammonia salts of said acids, as these said salts are th salts which are most stable in warm to hot aqueous solution, especially in the presence of other basic ions.

The action of these said salts in warm to hot aqueous solutions upon the dried paint residues in used paint brushes appears to be one that is primarily solubilizing towards the resinous compounds of the dried paint and distintegrating and partly solubilizing as to the metallic oxide pigments present in the dried paint. The rapidity 4 Claims. .(Cl. 134-28) of the action of these said salts upon the dried paint residues in the used paint brushes is wide ly variable depending upon the amount and kind of dried paint present, the temperature ofthe aqueous solution, and the concentration of the said salts present in the solution, as well as the presence or absence of wetting agents and of soap and detergent compounds in the solution.

Generally, I have found that low concentrations of the said salts in the solution are more eifective than high concentrations, the chemical activity of the salts apparently increasing with increase in dilution or with the degree of ionization of said salts in the solution.

Generally, also, I have found that with any given concentration of said salts in the solution the presence of a wetting agent accelerates the rate of reaction of the said salts with the dried paint products in the brush.

Generally, also, I have found that the presence of soap compounds and other detergents in the solution facilitates and accelerates the disintegration of the dried paint products by promoting the dispersion and suspension of the released metal oxide pigments in th solution, and emulsification of the oils present and their polymerized and oxidized compounds in the solution.

Finally, I have found that it is generally desirable to employ a hot solution rather than a warm solution as the rate of paint solubilizing and disintegration increases with increase in temperature. The best temperature to employ depends somewhat on the type of bristle in the paint brush but I have found that as a general rule a solution temperature approximating 7 0-80 C. is safely utilizable with most brushes.

As specific examples of the present invention. but not as a limitation thereof, in the cleaning and renewing of used paint brushes containing dried paint residues consistin principally of oil paints used generally in the painting of the outside surfaces of wooden or frame houses, I prepare an aqueous solution of one of the above identified salts of the said amino polyacetic acids containing about two level tablespoons of the the dry salt per quart of water, or a concentration of about 5 grams of the said salt per 100 c.c. of solution, heat the solution to about C., immerse and agitate the used brush therein for an extended time interval until the paint residues therein are removed from the brush and the bristles feel soft and pliable, then rinse the brush thoroughly in clear water and'dry the brush.

The precise time interval of immersion and agitation of the brush in the solution will vary widely, depending upon the amount of the dried paint present in the brush, as one skilled in the art will recognize. but with brushes heavily impregnated with dried paint the time interval normally is only from 10 to 30 minutes.

By the addition to the solution of only a few grams per quart of solution of a wetting agent, such 'as lauryl sulfonate or the sodium salts of sulfonated hexyl alcohol, the time of immersion and agitation of the brush in the solution is materially reduced sometimes as much as 50%.

By the addition of small amounts of alkali metal soap compounds or of other types of detergents to the solution of the order of a few grams per quart of solution, with or without the presence of a wetting agent in the solution, the removal of the paint deposits from the brush is-aiso materially accelerated due, it is believed, to the better dispersion and suspension of the metallic oxide pigments throughout the solution and emulsification of the oils present and their polymerized and oxidized products in the solution.

of the examples given of the amino polyacetic acid salts effective as paint solubilizing and disintergrating agents in accordance with the present invention, the tetra sodium salt of ethylene diamine tetraacetic acid in a concentration approximating 1 /2 ounces of a 30% aqueous solution of said salt per quart of hot solution at a temperature of about 75 C. has been found to be exceedingly effective alone or in the presence of wetting and/or soap and detergent compounds, in the removal of most paint residues.

The alkali metal salt of trimethyl amino-a,- a,-a"-tricarboxylic acid in concentrations apper quart of solution gives equally as good results.

The sodium salt of diethylene triamine pentaacetic acid in about the same concentrations given for the sodium salt of ethylene diamine tetraacetic acid, also gives substantially the same results.

All of the alkali metal and other salts above identified appear efiective within reasonable and economically practical lengths of time as soluproxiznating 2 level tablespoons of the dry salt I vpaint brushes which comprises immersing and agitating the brushes in a warm to hot dilute aqueous solution of a water soluble salt of an amino polyacetic acid for a time interval eifective to obtain a solutioning and disintegration of the resinous dried paint present in the brush by said water soluble salt of said amino polyacetic acid and suspension of the paint pigments in said solution, and then rinsing the brush in clear water and drying the same.

2, The method of claim 1. wherein'said solution contains also a wetting agent.

3. The method of claim 1, wherein said solution contains also a detergent compound.

4. The method of claim 1, wherein said amino polyacetic acid consists of ethylene diamine tetraacetic acid.

LUIGI ROTELLI.

REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,280,162 Catlett Oct. 1, 1918 2,240,957 Munz May 6, 1941 2,396,938 Bersworth Mar. 19, 1946 2,407,645 Bersworth Sept. 17, 1946 2,412,945 Bersworth Dec. 24, 1946 2,438,038 Craver Mar. 16, 1948

Claims

1. THE METHOD OF CLEANING AND RENEWING USED PAINT BRUSHES WHICH COMPRISES IMMERSING AND AGITATING THE BRUSHES IN A WARM TO HOT DILUTE AQUEOUS SOLUTION OF A WATER SOLUBLE SALT OF AN AMINO POLYACETIC ACID FOR A TIME INTERVAL EFFECTIVE TO OBTAIN A SOLUTIONING AND DISINTEGRATION OF THE RESINOUS DRIED PAINT PRESENT IN THE BRUSH BY SAID WATER SOLUBLE SALT OF SAID AMINO POLYACETIC ACID AND SUSPENSION OF THE PLANT PIGMENTS IN SAID SOLUTION, AND THEN RINSING THE BRUSH IN CLEAR WATER AND DRYING THE SAME.