US2065769A - Coated object and process of making the same - Google Patents

Description

Dec. 29,` 1936.

E. H. TRUSSELI..Y 2,965,769

COATED OBJECT AND PROCESS OF MAKING THE SAME Filed March 6, 1934 Patented Bec. 29, 1936 ATE UNITED s PATENT criss COATED OBJECT AND PROCESS 0F MAKING THE SAME `Emory H. Trussell, Newark, N. J., assignor to lBeckwith-Chandler Company, Newark, N. J., a corporation of New Jersey This invention relates to coated objects and to the method of providing surfaces with an improved nish for decorative or protective purposes. The improvement pertains generally to the surface characteristics of lacquer coatings.

Heretofore in the production of a smooth iinish on rough surfaces, such as Wood or metal with file marks, pit holesY etc., with cellulose ester lacquers and particularly cellulose nitrate lacquers serious difficulties arose from the use of the strong solvents of the nitrate lacquer in that they dissolve the undercoaits which were used to build up the `priming and filling coats for the rough object. The undercoats become swelled and more or less raised out of the imperfections in the surface and -onA the Aevaporation of the solvent draw back down to an irregular film showing indentations for each of the rough spots in the surface of the object coated. Furthermore in the building of a| quick air drying finish on rough objects of this nature it is very desirable to use undercoats which not only stick to the surface ofthe object and iill the imperfections in the surface, but also dry hard quickly principally by the evaporation of solvents. For this purpose primers and surfacersbuilt around a cellulose ester base, and particularly nitro-cellulose base, have been and are used very extensively. Now when this type of undercoat is used and the finish or color coat of cellulose ester lacquer are thereafter applied, not only is there a dissolving of the undercoat which results in the swelling and pulling out of the imperfections in the surface of the, object coated but also when the solvents evaporate the entire surface takes on a soaked in Ior microscopic pitted appearance due probably to a complete amalgamation of the two films. lIn order to overcome this appearance, it is necessary to rub andpolish the surface, when it has thoroughly dried, with an abrasive and polishing material.

The aforementioned diiiiculties are somewhat overcome in the production of cellulose ester -finishes at present, by the use of undercoatsv ness undesirable for a good decorative finish.'

This unevenness can be and is removed by the rubbing and polishing operation after the lacquer has dried thoroughly.

In the present invention the above mentioned. difliculties due to the dissolving of one coat by the application of succeeding coats are overcome by using as a finishing coat of lacquer 'over a cellulose ester lacquer, a composition containing as its base cellulose ethers suchl as benzyl and ethyl cellulose which are soluble in coal tar hydrocarbons such as benzene, toluene, xylene and high flash solvent naphtha or mixtures of these hydrocarbons with relatively small proportions of cellosolve (generally known to be mono-ethyl ether of ethylene glycol) or one or more alcohols such as butanol, the amyl alcohols, etc. These hydrocarbon materials or the aforesaid mixtures are not solvents for the cellulose ester iilms and by taking advantage of this fact the cellulose ether coatings may be applied over a base of nitrocellulose or cellulose ester undercoat Without soaking in or softening to the pointy that the base coat is drawn from imperfections in the surface to be coated.

To more specifically explain the present invention, the surface of the object to be coated may be coated with primer and iiller of nitrocellulose base, and sanded smoothly when dried to get a perfectly level or smooth surface. Then a finished decorative coat or coats of benzyl cellulose base lacquer are applied. The resulting finish when properly formulated for the method of application will dry to a smooth even surfaceV not showing any of the imperfections in the surface coated and not having the soaked in or micro pitted appearance. If, however, the same nitrocellulose base had been used in the nished coat of lacquer, the solvents would have dissolved the nitrocellulose undercoat `and the resulting dried lm would have been rough and uneven with a soaked in or micro pitted appearance.

In certain instances, the surface of the object to be coated may first be primed with other types of material such as drying oil base or synthetic resin base material. Then after they are sufiiciently dried an intermediate coating or filling coalt of cellulose ester such as'cellulose nitrate is applied, thoroughly dried, sanded and a top coating of the cellulose ether lacquer vapplied as a nish coat. By this method the same objects of the invention are accomplished.

An object of the' present invention is to provide a processby which solid objects are produced having smooth or glossy finishes by the use of lacquer materials.

A further object is to provide coated articles,

l the surfaces o'f which have a finish that is practically free from imperfections that are ordinarily encountered in lacquer coatings v-that have not received a rubbing or polishing treatment.

From the aforementioned facts, it can be seen that a still further object of my invention is to produce a quick drying finishfor wood, metal, and like objects, as well as fibrous sheets. For the purposes of the present invention, cloth or felt or other sheet materials may be considered solid objects. The finish is smooth or glossy as may Le desired without the laborious task of rubbing' and polishing` the nal coat. The success of my invention lies in the fact that a cellulose ether coating, and more specifically a benzyl or ethyl cellulose coating, containing a solvent mixture that does not dissolve the preceding'coat which is of a cellulose ester base, more specifically cellulose nitrate or acetate, when the finishing coat is superimposed on the cellulose ester coating.

'Ihe present invention is illustrated in the accompanying drawing, in which:

Fig. 1 is a sectional view showing a supporting element with a surface having an inner' coating of nitrocellulose or cellulose ester base material and an outer coating of cellulose ether base material; and

Fig. 2 is a sectional view showing a supporting element with a surfacehaving a primer coat of oil base or oil and resin base material, an

intermediate coat of nitrocellulose or cellulose ester base material and an outer coat of cellulose l ,from pigmented .or from clear liquid compositions. The rate of evaporation of the solvents used can be regulated, in the well known manner, from a very rapid rate, like the fastest drying lacquers, to a medium speed comparable to that of the more rapidly drying enamels.

'Ihe various ingredients employed in the lacquers are selected to provide compatible mixtures as is understood in the art. For instance, ethyl cellulose is considered compatible with natural resins such as damar as well as both the phenol aldehyde and the resins of the alkyd type including for instance glycerol phthalate synthetic types, both pure and modied. On the other hand, the benzyl cellulose is not considered compatible with the majority of the natural resins such as damar, but it considered compatible with those of the synthetic types mentioned above. Rapid developments have been and are being made in the field of synthetic resins. Exiellent results have been obtained with lacquers containing combinations of benzyl cellulose and glycerol phthalate synthetic resins. I have prepared filmsl that are dry and clear and with very bright glossy surfaces, from combinations in which the proportions of cellulose ether to glycerol phthalate resins .varied from equal parts of cellulose ether and` resin to cases where four or ve parts' of the resin to l Parts Tale 150 Zinc nxidn 150 Dry nitrocellulose I 100 Tricresylphosphate 35 Blown castor oil 40 Solvent mixture composed of proper balance of ester solvents (such as ethyl, butyl, or amyl acetates) alcohols (such as butonal, ethanol, etc.) and hydrocarbons (such as toluene, xylene, or even portions of fast evaporating petroleum naphthas) It is understood that the hydrocarbons in the above formula are included merely as diluents in the well known manner and proportions. The proportions are limited only to such an extent as will cause no precipitation of the nitrooel` lulose material.

The. composition'of this undercoat may be varied widely as long as it adheres to the metal surface, fills the imperfections and is built on a nitrocellulose, or cellulose ester base insoluble in toluene, xylene, etc.,. or mixtures of these hydrocarbons and alcohols containing a major portion of hydrocarbon. After this undercoat is dried, it is rubbed, by which is meant sanded smooth with fine abrasives. Then a finish coat of the following composition may be applied:

- Parts Antimony oxide 230 Plastic alkyd resin 230 Benzyl cellulose low viscosity -50 Xylenn v 540 Butanol 85 The composition of this finished coat may be varied between wide limits as long as it is built around a cellulose ether base and is composed of ingredients that are compatible and soluble in the solvent mixture used. This finish may be made in various colors or clear.

Ezample'2.-As another example of my invention, I mayuse as a priming coat for a metal surface a lcomposition of a drying oil type or oxidizing synthetic resin type as follows:

Drying oil type of undercoat:

l Parts* Pigment-mixture of iron oxide and inerts or any suitable mixture known to one familiar with the art -e 100. Fixed vehicle-composed of mixture of 'drying oils such as linseed and Chinawood oils with resins s uch as East India resin,fester gum. etc. properly blended and heat treated to sive desired drying time familiar to one in the art 50' Timmer-usually petroleum distillate or mixture thereof with turpentine 50-60 oxidizing synthetic Vresin types of undercoat:

Pigment of suitable mixture. 100 Resin such as of the alkyd type 40.

Solvent vauch as xylenel or mixed solvent suitable for purpose l00 2. A'process of manufacturing a coated metal object, whichvprocess comprises applying a cellulose ester lacquer to a surface of said object,

drying and rubbing the coating formed on said,

mitting the cellulose ether lacquer coating to dry to thereby form a smooth, finished surface.

3. A process of manufacturing a coated metal object, which process comprises applying to a surface of said object a priming coat, then applying a cellulose ester lacquer coating and finally a cellulose ether lacquer coating, thesaid cellulose ether lacquer applied to said cellulose ester lacquer coating containing hydrocarbon solvent material that is not a solvent for the cellulose ester, thereby forming a smooth, finished surface.

4. A process of manufacturing a coated metal object, which process comprises applying to a 'surface of saidobject a coating containing a cellulose plastic that is not dissolved by low boiling hydrocarbons alone, applying directly to the surface of said coating a solution of cellulose v' ether in a solvent containing low boiling hydrocarbon liquid in such proportion that the solvent c doesI not soften the said cellulose plastic coating, and permitting the said solution to dry on the said rst coating to thereby form a smooth, finished surface.

5. A process of manufacturing a coated metal object, which process comprises applying the following composition to a surface of the said object to form a coating:

Talc 150 Zinc oxide 150 Nitrocellulose 100 Tricresyl phosphate Blown castor oil Solvent 1100 applying to the coating resulting from the above application the following composition:

Parts by weight Antimony oxide 230 Plastic alkyd resin 230 Benzyl cellulose of low viscosity 50 Xylene 540 Butanol 85 and permitting drying of the resulting object to form a smooth, finished surface.

6. A process of manufacturing a coated metal object, which process comprises applying to a surface of the said object a priming coat containing 100 parts by weight of pigment and 100 to 140 parts by weight of a mixture of binder material and solvent, applying to the priming coat resulting from the above application the following composition:

applying'to the .surface of the coating resulting from the application ofthe last-named composition the following composition:

Parts by weight Parts by weight Antimony oxide 2 30 Plastic alkyd resin 230 Benzyl cellulose of low viscosity 50 Xylene f 54;()` Butanol -85 and permitting drying of the resulting object'to form a smooth, finished surface.

7. A process of manufacturing a coated'lnetal object, which process comprises applying toa surface of the said object a coating containing cellulose plastic that is not dissolved by lowboiling hydrocarbons alone, applying directly vto the said coating -a cellulose ether lacquer, the solvent in which contains low-boiling coal tar hydrocarbon liquid material in predominating proportions as compared with other constituents of the said solvent, thereby'inhibiting softening 'uniformly smooth'surface characterized by, being free from that pitted appearance resulting from the application of cellulose ester coating compositions to inner coatings of cellulose ester.

9. An article of manufacture produced by the metal supporting element having a plurality of coatings thereon including a priming coat, an intermediate coating of cellulose ester-containing material and a superposed outsidev coating of cellulose ether-containing material,l theV latter coating having a uniformly smooth surface characterized by being free from that pitted appearance resulting from the application of coatings prcess of -claim 3, the said article comprising a 35 of cellulose ester4 to inner coatings of cellulose ester.

10..An article of. manufacture produced by the process of claim 5, the said article comprising a metal supporting element having a plurality of coatings thereonincluding an inner coating resulting from the application of substantially the y following composition: l

n Parts by weight Talc 150 Zinc oxide 150 Nitrocellulose 10Q Tricresyl phosphate 35 Blown castor oil 40, Solvent 1100 and a Asuperposed outside coating resulting from the latter coating having a uniformly-smooth surface characterized by being free from that pittedappearance resulting from the application of coatings of cellulose ester on inner coatings of cellulose ester. f

the application of vsubstantially the following composition:

Parts byweight y Antimony oxide T 23o Plastic alkyd resin 230 Benzyl cellulose of low viscosity 50 Xylene 540 Butanol 85 vEither of these materials or suitably varied compositions of their nature are applied to the metal surface permitted to dry for the required length of time known from the formulae used,

and then a surfacing coat of nitrocellulose such` as the one mentioned above is applied over it to fill imperfections in the metal and act as a base V for the top coat of cellulose ether lacquers such as the'one mentioned above.'

It willbe obvious to one familiar with the art that numerous compositions of the aforementioned nature are available and suitable for the purpose intended and that such procedure of building a iinish is readily adaptable to vother types of rigid surfaces such as wood, press board, and materials of that nature.

For example, other types of cellulose ether Allwd resin solution composed of 1 part of what is vknown in the trade as rezyl 1102 and 1 part xylol 96 Xylol 45 Butyl alcohol (butanol) 1l Clear benzyl cellulose lacquer Partsv Benzyl cellulose 100 Rezyl 1102 300 Xylene 835 Butanol 90 `Butyl cellosolve 5 It.will be noted that there is a small quantity of butyl cellosolve (mono butyl ether of ethylene glycol) present in this formula. This material,

while a solvent for the whole film, when used in small quantities doesnot appreciably dissolve the undercoat and, materially improves the compatibility of the resin and ether as wellas helps the flow of the finished-coat.

White. benzyl cellulose lacquer Parts Antimony oxide 100 Rezyl 1l02 100 Xylol 100 Butanol 10 Butyl cellosolve 22 39301 base 110 Xylol 119 Butanol-; 13

Colored benzyl cellulose lacquer Parts Chrome green pigment j 40 Rezyl 1102 150 Benzyl cellulose 'l5 Xylene 660 Butanol 63 This formula produces agreen lacquer -and demonstrates the use of a reduced quantity of resin in proportion to the benzyl cellulose.`

Clear lacquery Parts Benzyl cellulose 100 Alkyd` resin known in the trade as Amberol 801 150 Dibutyl phthalate 30 Xylol '165 Butanol Butyl cellosolve 8*/2 This formula demonstrates the use of the benzylcellulose lacquer in the clear state and also shows a combination of this ether with a synthetic plasticizer and hard synthetic resin.

Clear ethyl cellulose lacquer Parts Ethyl cellulose Damar gum (dewaxed) 100 Dibutyl phahalate 30 Toluene 300 Xylene 400 Butanol 'l5 This formula shows the use of ethyl cellulose with the natural resin damar and dibutyl phthalate plasticizer. The combination makes an excellent clear finish 'for decorative purpose.

Colored ethyl cellulose lacquer Parts Para red pigment 40 Ethyl cellulose 100 Alkyd resin known in'thetrade as Lewisol Dibutyl phthalate 25 Xylene 770 Butanol 85 l Butylcellosolve 5 The above Aformula shows the further use of ethyl cellulose in a red lacquer, making use of an alykd type resin and synthetic plasticizer.4

These are only typical formulae and numerous other combinations of resins in the alkyd class as well` as the phenol aldehyde class can be used.

Cellulose ether coatings of the type set forth have excellent levelling properties and are in general very alkali and water resistant. In the application of cellulose ether lacquers to the process of the present invention, it is distinctly demonstrated that they do not soak into or soften undercoatings prepared from cellulose esters including cellulose nitrate or cellulose acetate but on the contrary leave such undercoatings unaffected and thereby dry to a smooth or glossy hard perfect finish.

. 'I'he proportions of ingredients in the formu- V.las given herein, are in parts by weight.

It is to be understood that the hydrocarbon solvent material for the cellulose ether lacquer,

referred to in the claims, is not considered av solvent for cellulose esters at those temperatures at which paints and lacquers are ordinarily applied for coating purposes.

What I claim is: 1

' 1. A process of manufacturing a coated metal object, which process comprises applying to a surface of said object a cellulose ester composition to form a solid film that is not dissolved by low-boiling hydrocarbons alone, applying directly to the surface of said illm a solution of cellulose ether in a solvent containing low-boiling hydrocarbon liquid in such proportion that the solvent does not softenthe said film, and permitting the said solution to dry on the saidillm to thereby form a smooth, finished surface.

1 1. An article of manufacture produced by the process of claim 6, the said article comprising a metal supporting element having `a plurality of coatings thereon including a priming coat, an intermediate coating resulting from the application of substantially the following composition:

n Parts by weight Tale 150 Zinc oxide 150 Nitrocellulose 100 Tricresyl phosphate 35 Blown. castor oil 40 Solvent 1 100 and a superposed outside coating'resulting frorn l the latter coating having a uniformly smooth 10 surface-clia1wacte-rized by being free from that pitted appearance resulting from the application of coatings of cellulose ester to inner coatings of cellulose ester.

EMORY H. TRUssELL. 15

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