US2419206A

US2419206A - Control of gloss in printing

Info

Publication number: US2419206A
Application number: US406073A
Authority: US
Inventors: Harry C Fisher
Original assignee: Consolidated Water Power and Paper Co
Current assignee: Consolidated Water Power and Paper Co
Priority date: 1941-08-08
Filing date: 1941-08-08
Publication date: 1947-04-22
Anticipated expiration: 1964-04-22

Description

April 22, 1947. H c. FISHER ,4

CONTROL OF GLOSS IN PRINTING I Filed Aug. 8, 1941 CALENDER INVENTOR. fl/14 C HSHEQ.

ATTORNEYS.

Patented Apr. 22, 1947 Q coN'raoL F GLOSS IN rnmrmc Harry G. Fisher, Cincinnati, Ohio, assignor, by mesne assignments, to Consolidated Water Power & Paper Company, Wisconsin Rapids, Wis., a corporation of Wisconsin Application August 8, 1941, Serial No. 406,073

My invention relates to processes whereby thenature of the surface of printing inks upon paper and paper board can be controlled for gloss in the final effect.

Irrespective of the smoothness of the finish of a piece of paper board or paper, it has been found practical by me, by certain sizing treatments in connection with the practice of coating the board, to control the gloss in printing to the end that a dull or mat surface can be provided, which is at the same time as smooth as practical. Thus, a surface which to all external appearance is one which will take a high gloss, smooth print-.

ing, can be made to be such that the printing will have a velvet or mat surface. The control is particularly valuable Where a color coating rich in binder is used to insure a high wax pick test.

The control-is applied previous to the coating step, by which I refer to the application of coat- -ings such as those in an aqueous vehicle containing finely divided mineral matter, such as clay and suitable binder substances, generally referred to as color coatings.

I have discovered that if application is made to the fibrous web, particularly where it is freshly made and moving continuously from a, paper or paper board machine, of a substance which is a penetrating Or wetting agent, then, following a color coating, drying and calendering, the surface of the coated fibrous web will be wettable or penetrable in controlled-degree to the vehicle of printing inks, thus leaving on the surface of the web a non-glossy final surface of dried ink.

film, as distinguished from a glossy final surface.

To illustrate an optional practice I have, in the appended drawings, shown a diagram of a practice applied to paper board whereby it may be color coated, dried and calendered prior to printing. In this diagram the web of paper board 2, is shown as coming from the final drying rolls l of a paper machine, after which it passes to the breaker stack or preliminary calendering operation comprising stack of rolls 3. From the breaker'stack which is equipp d With boxes 4, 4a, whereby the sizing employed by me in my practice is applied, the web may pass to a color coating apparatus which, as shown, consists of rolls 5, to which color coating is applied by means of applicator rolls 6 in a controlled amount.

Color will be drawn from a suitable fountain! and applied to the applicator rolls. The coating actic thus pursued wherein a film is established on a roll by an applicator roll and this film then transferred to a paper web brought into contact with the film, necessitates a heavy slurry 12' Claims. (01. 117-60) of pigment and binder and a thin film. In the claims that follow this mode of coating is referred to as printing. From the color coater the web may pass through drying and calendering equipment as indicated by boxes in the diagram suitably labeled to show purpose and relative location.

The substances which I have found to impart the penetrating quality or wetting quality when.

applied to the board before color coating, which quality continues after color coating, drying and calendering, ar generally penetrating or wetting agents, preferably of organic type such as butyl carbitol, the monobutyl ether of diethylene glycol, which is a, colorless and practically odorless liquid. Also, the sodium salts of sulphuric acid esters of the higher fatty alcohols are useful as penetrants, as well as others of the wide group of wetting agents similar in behavior to the alkyl sulphate or sulphonate materials, including, for example, the sodium salt of an alkyl naphthalene sulfonic acid. I do not limit myself to these particular wetting or penetrating agents, however.

Referring to the butyl carbitol, the amount used is not critical, and flat printing effects without gloss have been obtained with quantities varying from a few percent up by volume in the sizing applied in the breaker stack or previous thereto, whether this be starch or other size.

For example, in a companion applicationto the present one, Serial No. 412,831, filed September 29, 1941 now replaced with a continuation application Serial No. 501,320 filed September 4, 1943, I have disclosed a practice for preparing paper board or paper for color coating, which consists in the application of substances which are plasticizable, and yet water soluble, and

'which are applied to the boardat or ahead 'of the breaker stack of calenders to give it a surface size of adherent character. The penetrants or wetting agents can be added to the sizing substances of this process in quantities which will not break down the plasticizable nature thereof too far, with the result of permitting the very smooth finish and firm adhesion which is accomplished upon coatings and calendering as disclosed in said companion application, and yet promoting flatness in finish of printing upon the color coating. Alternatively, the penetrants or wetting agents can be applied to the board from solution or dispersion separate from that of the sizing substances.

. In one practice I have used on the breaker stack of calendersa five percent polyvinyl alcohol (PVA) size in water to five volumes of which I I have added one volume of butyl carbitol, the whole being kept hot during use. The application may be made by the breaker stack calender boxes as already noted or prior thereto. It is desirable, however, to apply the penetrating agent as close to the point of color coating as possible, but prior thereto, so that it does not dry too much before coming into contact with the wet color coating mixture. The barrier to ready wetting of the fibres of the paper board which is interposed by a plasticized layer of PVA, can be controlled, I have found, by the use of the penetrating agent, and in this way, the finish in printing with appropriate inks upon a board sized with the PVA and then color coated and calendered can'be controlled. In my opinion the result is due to facilitating the wetting of this barrier by the wet color coating due to the presence of the agent that facilitates wetting and to some degree of absorption of wetting agent and PVA into the color coating itself, thus changing the nature of the finished, dried, and calendered color coating and, in turn, its resistance to absorption of printing ink. Too much of the wetting or penetrating agent will destroy the plasticizable nature of the PVA. The wetting or penetrating agentshould be water soluble or compatible with any sizing or plastic agent with which it is employed, for practical reasons.

My invention applies to the use of starch size in the breaker stack or prior thereto (for example, in a size press in the drier section of the paper machine), 'or any other water soluble or dispersible surface size with or without a plastic agent which is also water soluble or dispersible.

In a typical practice using starch size in the breaker stack, I have mixed five volumes of starch solution of six percent concentration of low viscosity starch, by weight, with one volume of butyl carbitol. The hot mixture was applied to the surface of the paper board bymeans of the breaker stack calender boxes as already described, following which the color coatingwas applied, dried and calendered. When later printed with ink, the fullest in non-glossy characteristics of the ink was realized.

In still another practice, the penetrating agent, butyl carbitol, was added to a water solution containing both a plastic agent and starch. To

- four volumes of starch solutioncontaining six per cent low viscosity converted starch, by weight, were added one volume of polyvinyl alcohol of five per cent concentration in water, by weight, and to the hot mixture of 'these was added one volume of butyl carbitoLthe completed mixture being kept hot, and being applied to the paper board by calender box of the breaker stack of calenders. Following this the color coating was applied to the treated surface of the sheet, and was dried and calendered. Later the coated sheet was printed to develop the maximum in nonglossy characteristics of the ink.

Instead of mixing the wetting or penetrating agent into the sizing solution it can be applied to the'sheet of board as a separate solution from a means of application, either on the breaker calender stack or prior thereto as in a size tub. Thus, in the appended drawing the solution of plastic material, alone or in admixture with other sizing material such as starch, can be applied to one side of the sheet of board in breaker calender box I, following which the solution of wetting or penetrating agent is applied in calen- 4 ing operation, its drying and calendering of the coated sheet. Conversely, the wetting or penetrating agent can be applied to the board ahead of the plastic or sizing material as in box 4,

followed by the plastic or sizing material in box 4a, in which event the fullest in film-forming characteristics of the plastic or sizing material will not be developed because absorption of them into the surface of the sheet rather than retention on the surface will be promoted. However, for some purposes, as when the body of a sheet may have to be made highly resistant to penetration of solution, a surface treatment with penetrating or wetting agent before plastic or surface sizing material will prove advantageous. A similar treatment can be afforded the other side of the sheet. Where the wetting or penetrating agent is applied separately, it can be used in concentrated or diluted form as necessitated by the effect desired on the printed color coated sheet. I have used the liquid penetrating agent, butyl carbitol, in its concentrated form and also in dilution with water. A dilutionof three volumes water to one of butyl carbitol is effective, but I do not limit myself to such proportions,

In a typical practice of the invention, the sheet of paper board 2 coming from the final drying rolls l of the paper machine passes to and through the nips of calender rolls in the breaker stack 3. From calender box 4 of the breaker stack a water solution of plastic material and starch, as described above, was applied by nip pressure to the top surface of the paper board web. Immediately below on the breaker stack, in calender box 4a, the solution of wetting or penetrating agent was applied to the top surface of the board by nip pressure over the treatment of plastic material and starch. Since the time consumed by the sheet of board in passing from the calender nip at 4 to the one at 4a. is so short, a matter of a fraction of a second, the treating material applied by 4 is not dry by the time the treatment by do occurs, hence there is in reality amixing effect of one treating material upon the other resulting ina surface treatment of paper board especially suited for the reception of color coating to be dried and calendered, and then printed to produce the desired result of fiat or mat surfaced printing.

I have employed letter press printing in my process, the ink of which comprises pigments dispersed in linseed varnish along with the usual 00- balt or similar drier. and with a small admixture of wax such as ceresine to help prevent offset and enhance penetration. When printed upon paper or board such inks set to a slight degree by penetration into the surface upon which they are printed, but mostly by oxidation and polymerization of the vehicle. For extremely fiat printed effects the vehicle will comprise a preponderance of soft linseed varnishes, whereas for more glossy printed results the vehicle will contain harder linseed varnishes, many times in admixture with resinous materials. Since fiat printed effects are desired in the printed coated board of my invention, I naturally prefer to use inks formulated with that purpose in mind. However, it is not always possible to use the softest of inks when fiat printed results are desired because of adjustments necessary on the printing press and relationships between various colors and kinds of inks. This, then, makes my process particularly cause variations in ink formula can be made to der box in followed, inturn, by the color coatprovide for necessary requirements in it, while reliance is made on the treatment underlying the color coating to insure the fiat printed result.

The penetrating agent does not affect deleteriously the adherence of the color coating although there is an enhanced penetration of the vehicle of the coating. Apparently this enhanced penetration of vehicle of the coating in turn increases the ability of the dried and calendered color coating to absorb ink vehicle to produce a fiat printed effect. The precise reason why the fiat printed effect occurs is not obvious nor predictable from the nature of the material used.

The discovery that this effect does in fact follow is the essence of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks, which consists in applying a water wetting and penetrating agent to the surface of the web and then coating the web by printing it with a mineral coating in an aqueous vehicle and then drying the said coating.

2. The process for producing a coated surface on paper webs which will give a matimprint when subsequently printed with non-aqueous base inks, which consists in applying a water wetting and penetrating agent to the surface of the web and then coating the web by printing it with a mineral coating in an aqueous vehicle and then drying the said coating, said wetting and penetrating agent being an organic water a soluble compound.

3. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks, which consists in applying a water wetting and penetrating agent to the surface'of the web and thencoating the web by printing it with a mineral coating in an aqueous vehicle and then drying the said coating, said wetting and penetrating agent being butyl carbitol.

4. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks, which consists in applying a water wetting and penetrating agent to the surface of the web and then coating the web by printing it with a mineral coating in an aqueous vehicle and then drying the said coating, said wetting and penetrating agent being an organic water solublecompound of sulfated or sulfonated higher carbon chain fatty acids.

, '6 5. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks, which consists in applying a water wetting and penetrating agent to the surface of the web and then coating the web by printing it with a mineral coating in an aqueous vehicle and the drying the said coating, said wetting and penetrating agent being a salt of alkyl naphthalene sulfonic. acid.

6. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks,

which consists in applying to the'web a film of a plasticizable water soluble compound and a we.-

ter wetting and penetrating agent, then smoothing and compacting the surface of the web, then coating the smoothed and compacted surface by printing it-with mineral coat and finally drying and calendering the web.

7. The process of claim 6 in which the proportion of wetting and penetrating agent is not sufficient to render ineflectual the plasticizing property of the said plasticizable compound.

10 8. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks, which consists in applying a water wetting and penetrating agent to the surface of the web and then coating the web by printing it witha mineral coating in an aqueous vehicle, the paper web when the wetting and penetrating agent is applied being freshly made and then drying the coating.

9. The process for producing a coated surface web and then coating the web by printing it with a mineral coating in an aqueous vehicle and drying the said coating, the said wetting and penetrating agent being applied to freshly made paper in the breaker stack of calenders.

10. The process for producing a coated surface on paper webs which will give a mat imprint when subsequently printed with non-aqueous base inks. which consists in applying a water wetting and penetrating agent to the surface of the web and then coating the web by printing it with amineral coating in an aqueous vehicle, the mineral coat being applied immediately as a continuous step after applying the penetrating agent and then dried and the web calendered.

49 11. The process of claim 9 in which the minplied immediately as a continuous step after the smoothing and compacting step.

- HARRY C. FISHER.

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

UNITED STATES PATENTS Number Name 4 Date 5 1,777,459 Baddiley Oct. 7, 1930 1,995,623 Richter Mar. 26, 1935 2,240,031 Bour Apr. 29, 1941 2,214,565 -Montgomery Sept. 10, 1940 1,838,358 Bradner Dec. 29, 1931 2,005,397 Schur June 18, 1935 2,256,853 Schwartz Sept. 23, 1941 2,316,120 McLaurin Apr. 8, 1943 2,108,806 Finzel Feb. 22, 1938 2,045,517 Bruson June 23, 1936 05 2,105,982 Massey Jan. .18, 1938 2,251,296 Shipp Aug. 5. 1941 ,7 Q, FOREIGN PATENTS j Number W Country Date British Dec. 31, 1928