Non-transparent art paper which prevents seepage

Abstract

A non-transparent paper is described for non-transparent art or graphic design sketches, which prevents seepage of the inks, it accepts any type of gel, water-based, solvent-based, oil-based or mixed inks and solid materials for sketching and drawing, as well as fixatives for the solid materials. This paper consists of a lamination of at least two sheets of uncoated bond paper, inserting at least one intermediate layer of pigmented opacifying emulsion between both sheets, applied between the layers of paper to prevent transparency and the seepage of inks from one face of the lamination to the other. This layer of emulsion contains at least one opacifying pigment, at least one adhesive, agents to control viscosity and surface tension and other components. The outside layers of paper have a drying capacity which fixes the materials used for the sketching and prevent outlines made on one face passing to the adjacent sheets of paper, and also has a texture suitable for receiving any dry material for drawing or sketching.

Claims

1. A sketch paper for art and design applications comprising: (a) at least two base sheets of uncoated bond paper, wherein said two base sheets of bond paper are of the same type and same weight and wherein two of said base sheets of uncoated bond paper are the outermost layers of said sketch paper; and (b) at least one intermediate layer inserted between and coupled to said two base sheets, wherein said intermediate layer comprises an emulsion comprising at least one adhesive, at least one chemical opacifier compound having an average particle size of between 0.5 microns and 2 microns, at least one styrene copolymer emulsion, and at least one viscosity and surface tension control agent, and said sketch paper is substantially opaque.

2. The sketch paper of claim 1, wherein said at least one chemical opacifier compound is selected from the group consisting of carbon black, rutile titanium dioxide, anatase titanium dioxide, calcium carbonate, kaolin with laminar structure, calcined kaolin, white polymers, organic pigments, and inorganic pigments.

3. The sketch paper of claim 1, wherein said at least one styrene copolymer emulsion is selected from the group consisting of styrene-butadiene copolymers, styrene-acrylic emulsion copolymers, styrene-acetylated starch copolymers, styrene-oxidized starch copolymers, and styrene-low viscosity highly hydrolyzed polyvinyl alcohols copolymers.

4. The sketch paper of claim 1, wherein said at least one viscosity and surface tension control agent is an acrylic polymer.

5. The sketch paper of claim 1, wherein said at least one viscosity and surface tension control agent is a non-ionic surfactant.

6. The sketch paper of claim 5, wherein said non-ionic surfactant is polyethylene glycol tert-octylphenyl ether.

7. The sketch paper of claim 1, wherein each base sheet is impregnated on one side with a mixture comprising 50% carboxylated polyvinyl alcohol with 99% hydrolysis, 0.5% polyethylene glycol tert-octylphenyl ether, 45% insolubilizing resin, and 4.5% acrylic styrene prior to lamination, wherein said one side is the surface facing the other base sheet of bond paper.

8. The sketch paper of claim 7, wherein said insolubilizing resin comprises cationic polymers of polyamine-epichlorohydrin.

9. The sketch paper of claim 1, further comprising at least one synthetic resin, natural resin, or a combination thereof on at least one of the inside of each base sheet.

10. The sketch paper of claim 9, wherein said at least one synthetic resin, natural resin, or a combination thereof is selected from the group consisting of polyolefins, polyethylene, polypropylene, styrene acrylic resins, polyester resins, and additives selected from waxes and silicones.

11. The sketch paper of claim 1, further comprising at least one additional intermediate layer inserted between said two base sheets, wherein at least one such additional intermediate layer comprises one or more additional emulsions.

12. The sketch paper of claim 1, wherein at least one of said two base sheets is impregnated with one or more cationic wet strength additives.

13. The sketch paper of claim 12, wherein at least one of said base sheets is further impregnated with one or more carboxylated polyvinyl alcohols.

14. The sketch paper of claim 1, wherein the opacity of said sketch paper is between 88% and 99.5% TAPPI T-425.

15. The sketch paper of claim 1, wherein the TAPPI T-452 brightness of said sketch paper is between 88 to 90%.

16. The sketch paper of claim 1, wherein said at least two base sheets have a Gurley Hill porosity of between 20 and 10 sec/100 ml.

17. The sketch paper of claim 1, wherein said at least two base sheets have a weight of between 68 and 100 g/m.sup.2.

18. The sketch paper of claim 1, wherein said emulsion comprises kaolin with laminar structure, calcined kaolin, anatase titanium dioxide, rutile titanium dioxide, non-ionic surfactant, insolubilizer, acrylic emulsions, styrene acrylic polymers, and carbon black.

19. The sketch paper of claim 1, wherein the composition by percent weight of said emulsion is 10% calcined kaolin, 0.5% non-ionic surfactant, 0.5% insolubilizer, 58% acrylic emulsions, 30% styrene acrylic polymers, and 1% carbon black.

20. The sketch paper of claim 1, wherein the composition by percent weight of said emulsion is 5% calcined kaolin, 5% anatase titanium dioxide, 0.5% non-ionic surfactant, 0.5% insolubilizer, 59% acrylic emulsions, 29% styrene acrylic polymers, and 1% carbon black.

21. The sketch paper of claim 1, wherein the composition by percent weight of said emulsion is 5% calcined kaolin, 5% anatase titanium dioxide, 0.5% non-ionic surfactant, 0.5% insolubilizer, 58% acrylic emulsions, 30% styrene acrylic polymers, and 1% carbon black.

22. The sketch paper of claim 1, further comprising at least one additional intermediate layer of paper placed between said two base sheets, wherein said additional intermediate paper layer may be coated on one or both sides by resins, and wherein at least one resin is selected from the group consisting of polyolefins, polyethylene, polypropylene, styrene acrylic resins, polyester resins, and additives selected from waxes; and silicones.

23. The sketch paper of claim 1, wherein said emulsion has a dry thickness of between 3 to 8 grams per square meter (g/m.sup.2).

24. The sketch paper of claim 23, wherein said emulsion has a dry thickness of between 4 to 5 g/m.sup.2.

Description

EXEMPLARY EMBODIMENTS

(1) The following tables show exemplary implementations of the five embodiments previously described. In each case, at least one of the base sheets is applied with an aqueous emulsion using any suitable system used in the art for impregnating or covering base papers such as, but not limited to, air blade or color-dispensing bound rod, calibrated spray jets, rotogravure roller, or scraper.

(2) Table I depicts exemplary implementations of the first three embodiments described above. In each of these three exemplary implementations, the aqueous emulsion was applied, and its thickness calibrated, using a color dispensing bound rod to give a dry thickness of between 3 and 8 grams per square meter (gsm) and, more specifically, of 4 to 5 g/m.sup.2.

(3) TABLE-US-00001 TABLE I Embodiments 1-3 % Weight Example No. 1 2 3 Kaolin with laminar structure 5 Calcined kaolin 5 10 5 Calcium carbonate Rutile titanium dioxide Anatase titanium dioxide 5 Ultra reopaque synthetic polymer Acetylated starch Polyvinyl alcohol with hydrolysis of 99% TRITON x-100 SURFYNOL ct 171 0.5 0.5 0.5 Insolubilizer 0.5 0.5 0.5 Antifoamer Acrylic emulsions 58 58 58 Styrene acrylic polymers 30 30 30 Carbon black 1 1 1 TOTAL 100 100 100

(4) In another embodiment, the composition by percent weight of the emulsion may be 5% calcined kaolin, 5% anatase titanium dioxide, 0.5% non-ionic surfactant such as SURFYNOL ct 171, 0.5% insolubilizer, 59% acrylic emulsions, 29% styrene acrylic polymers, and 1% carbon black. In these exemplary embodiments, the opacity of the sketch paper is achieved by using an aqueous emulsion with one or more white pigments having a high refraction index. White pigments such as kaolins, calcined kaolins, calcium carbonate, synthetic polymers and titanium dioxide, due to their optic properties, are substances with a higher level of refraction (2.4, as a diamond). Even when pulverized or mixed with other loads, the average size of a 0.5 micron particle pigment provides a greater covering power and for this same reason is very opaque. The calcined kaolins are also an alternative to provide opacity due to the laminar form of the particles and because of the small particle size of only 1 to 2 microns also contributes to ink absorption.

(5) Table II shows exemplary implementations of the fourth embodiment according to the present disclosure, wherein the two base sheets may be impregnated, prior to lamination, with a solution of insolubilizing agents that absorb to the paper fibers, together with carboxylated polyvinyl alcohols to provide a protective barrier.

(6) TABLE-US-00002 TABLE II Embodiment 4 % Weight Example No. 1 2 3 Carboxylated polyvinyl alcohol, Hydrolysis 50 40 40 of 99% TRITON x-100 0.5 0.5 0 0.5 Insolubilizing resins 45 55 0.5 Antifoamer Acrylic styrene 4.5 59 Styrene-butadiene polymers 4.5 TOTAL 100 100 100

(7) In these exemplary implementations, base sheets having a porosity of between 20 and 10 sec/100 ml Gurley Hill may be used with previous priming in the paper machine. This may provide sufficient absorption to be receptive to the inks or emulsions. In such embodiments, an aqueous emulsion containing white loads and an adhesive, as described with respect to the embodiments shown in Table I, may be applied to the first base sheet by means of a rotogravure system. An emulsion promoting adhesion may be applied to the second base sheet. The two base sheets may be laminated together by means of a mechanism operated by steel cylinders.

(8) Table III shows exemplary implementations of the fifth embodiment according to the present disclosure, wherein the sketch paper further comprises an intermediate layer of paper placed between the two base sheets, and wherein this intermediate paper layer is coated on one or both sides by resins.

(9) TABLE-US-00003 TABLE III Embodiment 5 % Weight Example No. 1 2 3 Insolubilizing resins 5 5.0 Polyester resins 50 Styrene-acrylonitrile polymers 50 15.0 Styrene-acrylic copolymers Styrene-butadiene copolymers 20 50 Antifoamer 0.5 0.5 0.5 Calcined kaolin 44.5 15 15 Synthetic pigment 14.5 14.5 TOTAL 100 100 100

(10) Various measurements were made with respect to each exemplary implementation described above. A Thwing Albert, Progage model, series No. 45523 micrometer recording readings in mm, microns, thousandths of an inch and points was utilized for measuring the variables to be controlled. An X-rite series No. 530 spectrodensitometer was used to measure surface density, and opacity and whiteness on the outside faces of the base papers. Additionally, an Ohaus Scout pro sp202 scale and a Thelco model 18 oven were used to measure the weight and moisture content of the sketch paper in each of the examples described above. The results are given below:

(11) TABLE-US-00004 TABLE IV Comparison of Embodiments 1-3 Embodiment 1 Embodiment 2 Embodiment 3 Example No. 1 2 3 1 2 3 1 2 3 Basic weight g/m.sup.2 68 90 85 Weight g/m.sup.2 142 140 142 186 185 186 176 174 176 TAPPI T-410 Caliper Thousandths of an Inch 7.0 6.8 6.9 8.0 8.1 8.2 7.3 7.4 7.3 TAPPI T-411 Moisture Content % 4.5 4.5 4.3 4.5 4.5 4.3 4.6 4.4 4.5 TAPPI-412 Opacity % 92 90 91 96 97 98 94 95 94 TAPPI T-425 Density Whiteness T-452 89 90 90 90 88 89 90 90 89

(12) TABLE-US-00005 TABLE V Comparison of Embodiment 4 Embodiment 4 Example No. 1 2 3 Basic weight g/m.sup.2 85 Weight g/m.sup.2 176 174 176 TAPPI T-410 Caliper Thousandths of an Inch 7.2 7.3 7.4 TAPPI T-411 Moisture Content % 4.3 4.0 4.4 TAPPI-412 Opacity % 98 98 99 TAPPI T-425 Density Whiteness T-452 89 90 89

(13) TABLE-US-00006 TABLE VI Comparison of Embodiment 5 Embodiment 4 Example No. 1 2 3 Basic weight g/m.sup.2 72 Weight g/m.sup.2 230 230 230 TAPPI T-410 Caliper Thousandths of an Inch 10.5 10.5 10.5 TAPPI T-411 Moisture Content % 4.3 4.2 4.0 TAPPI-412 Opacity % 99 99.5 99 TAPPI T-425 Density Whiteness T-452 89 88 88