US1884769A - Heavy-bodied finish remover containing alpha corrective of antipenetration - Google Patents

Description

Patented Oct. 25 1932 '[UNITED STATES PATENT OFFICE BORIS N. LOUGOVOY, OF NEW YORK, N Y., ASSIGNOR 'IO CHADELOID CHEMICAL COMPANY, OF NEW YORK, N.

Y., A. CORPORATION OF WEST VIRGINIA HEAVY-BODIED FINISH REMOVER CONTAINING A CORRECTIVE OF ANTIPENETRATICN No Drawing.

This invention relates to a finish remover especially adapted for work on vertical surfaces and particularly refers to a heavy bodied mixture containing wax and nitrocellulose and.so balanced as to produce the quickest possible action when applied to a painted. surface.

With a general type of remover composed of a mixture of solvents with an appropriate 7 proportion of wax, such as, for example, re-

movers containing mixtures of benzol and acetone with or without alcohol, to which 3 to 5% of wax has been added, there is often difficulty in working on vertical surfaces be cause such removers run down and conse quently the remover does not stay in contact With the finish on the upper part of the surface sufiiciently long to produce the desired loosening action on the paint.

It therefore has been deemed necessary to produce a type of paint and varnish remover which will stay on vertical surfaces without running down. This has usually been accomplished by increasing the body of the remover by incorporating substances capable of forming colloidal solutions such as esters of cellulose, soaps, etc. Nitrocellulose in the form of old moving picture film or celluloid scrap isthe most Widely used ma- 3; terial for such purpose. An increase in the proportion of wax in conjunction with nitrocellulose also has been employed as a means to increase the body.

However, the addition of various solids is which are capable of dissolving in one of the solvents present in a paint and varnish nee mover will result in cutting down the speed of attack of a given solvent or of a mixture of several solvents, and therefore the cutting speed or rate of attack of a remover and by nitrocellulose Application filed November 30, 1928. Serial No. 322,968.

wood was selected, taking care that the portion used had a good even, thick coat of paint,

and this was cut into strips. The solvent mixture to be tested was placed in a test tube and a strip of the painted wood was put into this test tube. The time which elapsed before the first appearance of any wrinkling was noted accurately by means of a stop watch. The comparative removing action was thus roughly represented by the number of seconds, being inversely proportional to these numbers. In addition to this, each completed paint and varnish remover composition was also tested on the same kind of a painted surface and under the conditions approximating the actual use of removers in practice. For this purpose a part of an old automobile (finished with an oil paint) was secured. Each remover was placed on the surface in approximately the same quantity and the time was noted by means of a stop watch when the blistering or wrinkling of the surface was plainly observable. The cutting power was then represented by the number of seconds which elapsed before the appearance of such wrinkling.

To improve the efliciency of the presently discussed type of paint and varnish remover, I proceeded first with the systematic investigation of the influence exerted by each antipenetrant separately, i. e., by paraflin wax dissolved in various paint andvarnish remover solvents upon the removing action of these solvents. This investigation led to many interesting and important observations which enabled me to produce a combination of ingredients in such a way as to minimize the harmful retarding effect of the above solids in regard to their influence upon cutting speed and efficiency of this type of remover.

The following mixtures of two types of paint and varnish remover solvents, one be-' ing a penetrating (or wax solvent) type and the other a loosening (or wax-precipitating) type, were studied, determining first the cutting rate of each mixture without the addition of any solid substance, such as wax or nitrocellulose. This cutting speed will later Abinute on t ng Solvents acflon seconds Benzol and acetone 70 Benzol and mnfhnnnl 40 Benzol and methyl acetate Benzol and lugosol" 45 Petroleum naphtha and acetone 240 Petroleum naphtha and methyl acetate 120' (Petroleum naphtha in these cases had a boiling point range to C.)

A series of samples were then made with each of the above mixtures incorporating in one case various proportions of paraflin wax; in the second case, various proportions of nitrocellulose second viscosity), and in the third case incorporating both wax and nitrocellulose simultaneously. The cutting speed or the activity of each mixture was measured on painted wooden strips as described above and the results obtained were calculated so as to represent a degree of retardation in percent of the absolute removing action of a given solvent combination.

The experiments now to be described show that the influence of parafiin wax and of nitrocellulose upon the activity of a paint and varnish remover is not of the same nature even for a given solvent composition. Examination of the above curves leads to the following conclusions:

Influence of parafiin wax as anti-penetrant:

1. Paraflin wax slowed down the removing action (cutting speed) of paint remover solvent mixtures.

2. The rate of slowing action or retardation due to the presence of wax, within limits,

- is proportional to the relative amount of wax included in the remover (roughly).

3. The retardation due to wax is relatively less with petroleum naphtha than with benzol for a given ,wax precipitant and a given amount of incorporated wax.

Nitrocellulose second viscosity) as anti-' penetrant:

1. This solid also decreased the removing action or cutting speed of a given solvent combination.

2. The retardation due to nitrocellulose is relatively greater than the retardation due to wax for a given solvent mixture.

- 3. For a given solvent mixture retardation due to nitrocellulose is proportional to the amount of nitrocellulose introduced into this solvent (only very roughly).

Anti-penetrants, parafiin wax and nitrocellulose jointly: I 1. For a given amount of nitrocellulose and paraffin wax in a given solvent mixture the relative retarding action approximately equals the sum total of individual retardation produced by each substance separately;

.solvents containing 2% For a' mixture of various. of wax and 1% of nitrocellulose second viscosity) this retardation was as follows:

for example:

In connection with the above figures it should be remembered that they represent only the relative value of the influence of either wax or nitrocellulose upon a combina tion of two solvents and for practical application they should always be used in reference to the absolute cutting action of a given mixture, as represented in the first table given above. For example: considering two mixtures, (a) benzol and methyl acetate and (b) petroleum naphtha and methyl acetate for a given proportion of nitrocellulose, say 5%, the first mixture will prove more desirable in spite of the greater relativel drop in efficiency due to nitrocellulose on account of the higher absolute cutting action of the pure solvent, because the actual activity of each of these removers will be as follows:

For benzol and methyl acetate mixture actual cutting speed will be 70 seconds 240 seconds+ 0 =240+43.4

about 283 seconds.

The solvent under the name of lugosol,

mentioned in this specification, 1s a product 3 obtained from acid-freeacetone by treating it with a small amount (a few tenths of one per cent) of caustic alkali, allowing it to condense for a day or more, neutralizing the alkali, and then distilling ofl unconverted acetone. Such solvent used in above examples was made by adding to oneliter of pure acetone one gram of powdered potassium hydroxide. The mixture was allowed to stand at roomtemperature for about sixty hours, then was neutralized with tartaric acid, the precipitate of potassium tartrate was filtered out and the filtrate was distilled, separating the fraction with the boiling point below 60 C. and the fraction with the boiling point above 60 C. This high boiling fraction represents one form of the solvent called lugosol. The term throughout the present case.

After determining experimentally the joint lugosol is so used paraffin wax and retarding action of bothanti-penetrants, i. e., second viscosity with cellulose for the amount given above, and

noting that the experimental data is very close to the volume of retardation calculated from the curves representing the retardation of each individual anti-penetrant, I proceed to determine if such observation will hold true for other variations in the relative amount of each anti-penetrant. The table be-. low shows that this is the case.

Joint retarding act-ion of Found $51 .55

1 per cent nitrocellulose and 1 per cent wax? Benzol and acetone 55 58 Benzol and lugosol 5O 50 Benzol and methyl acetat 2 Benzol and anhydrous methanol 25 2 per cent nitrocellulose and 4 per cent wax:

Benzol and acetone 120 127 v Benzol and luqosol 78 72 Benzol and methyl acetate 60 60 Benzol and anhydrous methano 55 5.2

Petroleum naphtha and acetone- 91 87 3 per cent nitrocellulose and 3 per cent wax:

Benzol and acetone 100 120 Benzol and lugosol 80 76 Benzol and methyl acetate 61 54 Benzol and anhydrous methanol 45 43 Petroleum naphtha and acetone 35 The above figures indicate that the experi- :mentally obtained calculated results can be considered reasonably close in view of the necessarily rather rough character of the tests.

The figures above given show that while one loosening solvent, such as acetone, may be a desirable ingredient in conjunction with one wax solvent, such, for example, as petroleum hydrocarbons, it will not be as suitable in conjunctionwith other kinds of wax solvents, such as benzol. In this latter case the above data show that if a ketonic solvent isdesirable it would be much more advantageous to use lugosol than acetone.

In order to confirm these theoretical observations, a number of paint and varnish removers have been made using a series of solvents in accordance with the experimentaldata above given.

This will be explained in discussing examples given below which illustrate the practical application ofthe theme of the present invention.

It is understood that all the formulas given below should be regarded only as examples and that I do not wish to restrict myself to the exact components and proportions given in these formulas. The mixtures of solvents in these examples are based on an interpre tation of the data given above in such a way as to compose removers from solvents whlch are less influenced by the addition of wax and nitrocellulose under given conditions, as will be explained in connection with example 9 given below. The cutting speed of each sample Was tested on a panel cut from an automobile body, as already described, and the .results of such determination concurred with the assumption drawn from the examination of the above diagrams. In all these examples the amount of solvents, wax and nitrocellulose are given in percent by weight.

Example 1 Parts Benzol Anhydrous methanol 25 Lugosol 15 Methyl acetate 15 Paralfin wax 3 Nitrocellulose (scrap celluloid) 2 The cutting speed of this remover was 80 seconds as against 250 seconds of commercial remover bought on the market and supposed to be one of the most active of the heavy bodied removers on the market.- This commercial remover contains benzol as the wax solvent, and the removers in Examples 1 to 5 and about the same body (viscosity, flow, etc.) as said commercial remover.

Example 2 I Parts Benzol 4O Anhydrous methanol 25 Methyl acetate -r. 30 Paraflin wax Nitrocellulose (scrap celluloid) 2 The cutting speed of this remover was 65 secdetermination of cutting speed of these two removers. j

' Example 3 Benzol 40 parts. Anhydrous methyl alcohol 25 parts. Acetone 15 parts. Methyl acetate 15 parts. Paraffin wax 3 parts. Celluloid scra 2 parts. Cutting speed jnn 100 seconds.

The cpmposition of this example differs from the composition given in Example 1 by replacing lugosol with acetone.

Reference to the above tables shows that the benzol, acetone mixture sufiers a much greater retardation by addition of wax and nitrocellulose, than benzol and lugosol mixture, and therefore the replacement of lugosol with acetone would result in the decrease of cutting speed. The comparison of cutting speeds of composition. #1 and the present composition concur with that conclusion.

Ewample ,4

Light petroleum distillate (B.

P. 60 to 85 C.) 30 parts. Anhydrous methanol 25 parts. Methyl acetate 40 parts.

Paraffin wax 3 parts. Celluloid scrap 2 parts. Cutting speed 240 seconds.

Example 5 Petroleum distillate (B. P. 60

to 85 30 parts. Anhydrous methanol 25 parts. Acetone 40 parts. Parafiin wax i 3 parts. Celluloid scrap; 2 parts. Cutting speed 180 seconds.

In comparing the cutting speeds of Examples #4 and 5, it can be seen that the composition of Example #5 is much speedier than that of Example #4. The difference in the composition of Example #5 is that methyl acetate in Example #4 was replaced with acetone. Lugosol could also be substituted.

This increase in speed is in accord with the data showing the petroleum acetone mixture to have a lower retardation than the petroleum methyl acetate mixture.

It is here worthy of remark that although i the removers of Examples 4 and 5 both contain petroleum hydrocarbons as wax solvents,

both the removers are essentially'more highly on the market.

I claim:

1. A finish remover containing petroleum hydrocarbons substantially all boiling at below 85 C., functioning as the essential wax solvent, and containing wax in amount sufficient to give a heavy bodied remover, and containing relatively volatile wax precipitants in such amount as to form a highly active finish remover, the wax precipitants including one at least of the substances of the group consisting of anhydrous methanol, an-

hydrous methyl acetate, acetone and lugo-' sol, such remover having a cutting speed of at least 240, the wax precipitantsibeing in excess over the wax solvent.

precipitant selected from the group consisting of substantially anhydrous methanol, methyl acetate, acetone and lugosol.

3. A finish remover having about the following composition- Parts Benzol 40 Anhydrous methanol 25 Lugosol 15 Methyl acetate 15 Paraflin wax 3 Nitrocellulose 2.-

4. A finish remover having about the following composition Parts Benzol 40 Anhydrous methanol 25 Methyl acetate 30 Parafiin wax 3 Nitrocellulose 9 5. A finish remover having about the following composition P t 11' S Petroleum distillate (B. P. about 60 to 85 C.) 30 Anhydrous methanol 25 Acetone 40 Paraffin wax 3 Celluloid scrap 2 6. A finish remover having the following composition Wax solvent, consisting of hydrocarbons substantially all boiling between about 60 and 85 C 30 to 40 parts Wax precipitants selected from the herein described group consisting of anhydrous methanol, methyl acetate, acetone and lugosol 55 to parts Wax and nitrocellulose material together active than the best heavy bodied removers about 5 parts In testimony whereof I affix my signature.

BORIS N. LOUGOVOY.

2. A finish remover having petroleum hysolvents, at leastthe major part of its'wax