US1685355A - Streak-ribbed product and process of making same - Google Patents

Description

Patented Sept. 25, 1928.

UNITED STATES 1,685,355 PATENT OFFICE.

GARLETON ELLISQOF MON'ICLAIR, NEW JERSEY, ASSIGNOR 'IO ELLIS-FOSTER COI- IANY, A. CORPORATION OF NEW JERSEY.

I STREAK-REBED PRODUCT AND PROCESS OF MAKING sum.

No Drawing.

I This invention relates to sheeted material or plate and various molded or shaped products of novel appearance and to the process of making same. In a co-pending application Serial No. 742,719, I have described the formation-of striated molded articles by pressing together resin-impregnated multi-colored fragments of paper. In the present invention it is an object to secure striated products the striations of which are of a moreregular or uni form character than obtained by the process set forth in said application. Also in some cases I desire to obtain banded eifectsor parallel striation including the peculiar striped elfect employed in imitating ivory.

In carrying'out my invention I impregnate paper or other tissue which preferably should be unsized employing as the impregnating medium a resin preferably a synthetic resin in the mold when hot pressed at elevated temperatures. Phenol formaldehyde resins may be employed in some cases for this'operation especially for darker colors but generally speaking I prefer a light colored base in which the striations appear and the phenol formaldehyde resins are therefore not suit-' able for use in this way because of discoloration bylight. p ,1

A satisfactory resin fonthe purpose is however made by treatment of urea with formaldehyde. Such material may be obtained in its initialstage of conversion in the 'form of an aqueous syrup with which the paper may be impregnated. The urea formaldehyde resin maybe used by itself or it may be incorporated with other resins to secure a fluxing efl'ect. One .resin which is satisfactory for this purpose is that obtained by reacting on acetone with formaldehyde in the presence of an alkaline catalyst. A mixture of say one part of the acetone formaldehyde resin to three or four parts of the urea formaldehyde resin may be employed to advantage.

The tissue employedmay be ordinary tissue paper or parchment paper-or heavily calen-.

dered imitation parchment paper known as glassine paper. Heavier forms of paper such, as thin blotting paper may be employed in.

some cases also muslin or other thin cloth. Generally speaking I prefer to obtain a translucent product and the employment ofheavy paper which cannot be thoroughly impregnated to obtain translucency is objectionable Application filed October 25, 1924. Serial No. 745,987.

having the property of hardening or setting REISSUED for the purpose. The paper may be dyed different colors or the resin solution may be employed with different dyes or pigments or both the paper and the resin solution may be colored. Sheets of one color are piled one on another until the requisite thickness of that color is secured and then other sheets of a di'fl'erent color are piled thereon. In this way there may be built up a pressboard of any desired thickness. This is exposed to a pressure of 2000 pounds per square inch in a press at 125 C. for a period of 10 minutes or more depending on'the thickness of the pressboard. After cooling in a cold press a laminated product having differently colored strata is obtained. The pressboard is then sawed or cut transversely into small strips and these are placed together edgewise in the mold and re-pressed. In this way the positionof the stripes or strata is reversed and the surface of the pressed article now shows striations in parallel bands extending across its surface and through to the opposite side.

This method may be continued,'the article obtained by the second pressing being again out and-pressed or folded and pressed to obtain still more striking effects.

The strips referred to above before pressing ma be dipped in asolution of the urea formal ehydesyrup employed for impregna' tion (with or without acetone formaldehyde resin) in order to cause the surfaces of the strips tobett'er adhere on the second pressing.

Since in the first pressing, which preferably may take place at 110125 C., a slight amount'of setting may occur it is desirable to carry out the second pressing at a somewhat higher temperature, say 130 C. However if discoloration occurs at that temperature a longer periodat a lower temperature may be.

employed.

The banded ing of appearance due to the fact that the striations or bands formed by the dark lorsheets thus obtained are striked-paper show a vigorous contrast alon 'de like Instead of pressing in the form of a a sheet the material may be molded into various shapes such as receptacles of various kinds, handles and varlous ornamental articles.

Further b having the striations narrow and of a l g t brown tone alternating, with no broader bands of the color of ivory an efi'ect quite similar to ivory may be obtained.

A description of the method of making the urea formaldehyde resin intermediate syrup and the acetone formaldehyde resin and'their incorporation follows.

I Example 1.- -Urea resin syrup: 30 parts of urea are dissolved in 120 parts of aqueous formaldehyde and 3 parts of phthalic anhydride are added to the solution. The mixture is then slowly and gradually heated, the temperature being around 80-90 0., in a flask connected with an air condenser or a.w'atercooled reflux condenser. The heating is continued until the contents of the flask become clear and water white. The syrup so obtained is then cooled and stored. This syrup usually contains from to 55 per cent of solids. It can'be diluted with water to a 25 or 30 per cent solution without any danger of precipitation.

Example 2.Composite product: 7 5 parts of urea are dissolved in 325 parts of aqueous formaldehyde and to this 25 parts of molten phenol and 10 parts of phthalic anhydride are added. The mixture is then very gradually brought to slight boiling and is maintained at this point until the milky solution which is first formed gradually becomes clear and water white. Extensive boiling as well as sharp raising of the temperature should be avoided in order to prevent the possibility of coagulation of the syrup. To the clear syrup so obtained while still warm a small amount (2 or 3 per cent) of alcohol is added. This prevents-the syrup from turning milky on cooling Example 3.Acetone resin solution: 30 parts of acetone are mixed with 225 parts of aqueous 40 per cent formaldehyde in a large round bottom flask. 26 grams of per cent aqueous solution of pure sodium hydroxide are then added and the flask is allowed to stand in the cold. In a short time an energetic exothermic reaction is taking place and a sli htly yellowishgummy resin separates. on t e bottom. The reaction is checked at thls point by adding a large amount of cold water inorder to obtain an alcohol soluble resin. Thewater layer is then decanted and the resin is washed with water free from caustic and finally is dissolved in an amount of alcohol so as to form a 30 per cent solution.

The method of preparing thh mixed complex'solution is as follows:

(A) A 50 per cent solution of either syrup #1 or composite resin #2 is mixed withan equal weight of 30 per cent alcoholic solution of acetone resin #3 and the mixture used for mpregnation. Y

(B) he same 50 per cent urea syrup #1 could be mixed with 30 per cent solution of other light colored products soluble either in water or alcohol, as for example a glycerol tartrate, citrate or phthalate.

lmpregnation of paper may be carried out simply by soaking, or passing the paper through a bath of the solution. Or pressure and vacuum methods, known to the impregnation art, may be employed in some case.

' What I claim is 5- 1. A process. of making a streak-ribbed sheet material or plastic product which comprises impregnating sheets of thin paper with a synthetic resin comprising urea resin, superposing sheets of different colors, hotpressing to weld the sheets together to a edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucent product.

3. A process of making a streak-ribbed sheet material or plastic product which comprises impregnating sheets of thin paper with a synthetic resin, superposing sheets of different colors, hot-pressing to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make thin strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucent product.

4. A process of sheet material or plastic product which comprises impregnating sheets of paper with synthetic resin comprising urea and acetone resins, superposing sheets of diflerent colors, hotpressing to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make strips, asembling the strips edgewise in a hot press and pressing to weld the'strips together to form a streakribbed or variegated partially translucent product.

5. A process of making a streak-ribbed sheet material or plastic product which com- "prises impregnating sheets of thin paper of difierent colors with a synthetic resin comprising urea resin, superposingjsuch sheets of different colors, hot-pressing to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make thin'strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed or variegated partially translucent product.

6. A process of making a streak-ribbed making a streak-ribbed sheet material or plastic product which comprises impregnating sheets of paper with synthetic resins of different colors, superposing the resulting sheets of different colors, hotpressing to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make strips, assembling the strips e gewise in a hot press and pressing to Weld t e strips together to form a streak-ribbed or variegated partially translucent product.

7. A process of making a streak-ribbed sheet material or plastic product which c0111- prises impregnating sheets of paper of different colors with synthetic resins of different colors, superposing such sheets of different colors, hot pressing 'to weld the sheets together to a thicker sheet or block, cutting such pressed material transversely to make thin strips, assembling the strips edgewise in a hot press and pressing to weld the strips together to form a streak-ribbed orvariegated partially translucent product.

8. A process of making a. streak-ribbed sheet material or plastic product which comprises impregnating sheets of paper wit-h a synthetic resin comprising urea resin, superposing sheets of different colors, hot pressing to weld the sheets together, cutting such pressed material transversely to make strips, assembling the strips edgewise, and hot pressing to weld the strips together at a tempera.- ture higher than that used in the first hot pressing step.

9. Streak-ribbed translucent pressboard containing a light colored synthetic resin.

10. Streak-ribbed translucent pressboard containing urea resin.

11. Streak-ribbed translucent pressboard containing urea and acetone resin.

CARLETON ELLIS.