RU2264493C1 - Method of manufacturing jet-printing paper with pigmented coating and jet-printing paper with pigmented coating - Google Patents

Abstract

FIELD: paper-and-pulp industry.

SUBSTANCE: when ground paper is manufactured, it is coated with ink-accepting coating. The latter contains latex binder, water-soluble binder, pigment mixture of amorphous silica with colloidal cationic silica and colloidal alumina, and ink-fixing agent. Coating operation is performed in two steps, weight ratio of coating applied in the first step to that in the second step ranging from 0.34:1 to 0.66:1. Reverse face of base paper is coated by detwisting coating. Further, coating is ennobled via superglazing at pressure in supercalender roll gap 30-75 bar.

EFFECT: improved workability of process and improved quality of paper due to increased surface strength.

4 cl, 7 ex

Description

The invention relates to the pulp and paper industry, in particular to the production of inkjet paper with a special pigmented coating.

It is known that the most stringent requirements are imposed on inkjet paper, since the printing is carried out with wet ink, and the paper must provide high print quality and dry quickly, that is, have properties that are simultaneously difficult to achieve.

A significant amount of paper intended for inkjet printing is coated with special coatings of various composition to achieve certain characteristics of inkjet printing, many of which depend on the type and processing of paper.

Obtaining full-color images by inkjet printing with full filling of the sheet area requires the following properties: the ability of a strong fraction of the ink dye on the surface of the material and the rapid absorption of the liquid phase of the ink into the coating material without deforming it. Such requirements are due to the fact that ink is used on ink based either on aqueous solutions of dyes or on the basis of dispersions of dyes in a suitable liquid for this.

Lack of fixation of the ink dye on the surface of the coating leads to a decrease in the optical density of the image, and insufficiently fast absorption of the liquid phase of the ink by the coating material leads to defects such as color mixing, ink smearing when printing lines and small details, which makes the image wrinkled and fuzzy.

A known method of preparing paper for inkjet printing with a pigmented coating, comprising applying to the base paper a pigmented coating containing a pigment, a cationic type synthetic resin and silicon, a modified polyvinyl alcohol, subsequent application of an aqueous solution of a cationic resin, drying the resulting paper and calendaring (see JP 3155267 B2, B 41 M 5/00, 04/09/2001).

In this case, a mixture of silicon oxide with a specific surface of 365 g / m ² and aluminum oxide with the same specific surface is used as a pigment at a ratio of 1: 3.

Paper obtained in a known manner, has increased surface strength and good fixability of water-based paints.

A known method of manufacturing paper for inkjet printing with a pigmented coating, comprising applying to the base paper a pigmented coating containing an absorbing pigment of silicon dioxide, a binder of polyvinyl alcohol and a cationic fixative (EP 1090776 A1, B 41 M 5 / 00,11.04.2001) .

In this case, the pigment preferably consists of a mixture of 75% or more silica gel with a pore volume of (0.5-1.5) m ³ / kg and 10% or more alumina or alumina hydrate.

Paper obtained in a known manner also has good adhesion to aqueous ink.

The closest analogue to the technological essence of the claimed technical solution is a method of manufacturing paper for inkjet printing with a pigmented coating, which includes obtaining a base paper, coating it with an ink-receiving coating containing a latex binder, a water-soluble binder, amorphous silica pigment and an fixing agent ink, the subsequent application of anti-curling coating on the opposite side of the base paper and the refinement of the coating, perceiving ink (US 6410123 B1, B 41 M 5/00, 06/25/2002).

In this case, the refinement of the ink-perceptible coating is carried out by successive deposition of 2 layers based on colloidal silicon dioxide. At least one of the layers of colloidal silicon dioxide in contact with the paint receiving coating does not contain a binder and has a hiding power of 0.001-0.003 kg / m ² , while the other layer has a hiding power of 0.001-0.006 kg / m ² .

The inkjet paper obtained in a known manner has high ink absorbency and color-developing properties.

However, a three-stage coating that accepts ink with an intermediate finish is a very laborious, low-tech process.

A new technical result from the use of a technical solution is to increase the manufacturability of the process by reducing the number of stages when applying a coating that accepts ink, while maintaining high ink absorption and color-developing properties and improving surface strength.

This new technical result is achieved by the fact that in the method of manufacturing inkjet paper with pigmented coating, which includes obtaining a base paper, coating it with an ink-receiving coating containing a latex binder, a water-soluble binder, amorphous silica-based pigment and an fixing agent ink, the subsequent application of an anti-rolling coating on the opposite side of the base paper and the refinement of the ink-receiving coating as an amor-based pigment For full silica, a mixture of the latter with colloidal cationic silica and colloidal alumina is used at a weight ratio of the indicated pigment components, respectively (80-85): (10-15) :( 5-10), while coating the ink receiving coating is carried out in two steps with a ratio of the mass of the coating applied to the second step from 0.43: 1 to 0.66: 1, and the refining of the coating that receives ink is carried out by supercalanding at a pressure in the grip of the supercalender rolls of 30-75 bar.

In this case, aqueous dispersions of amphoteric or cationic styrene-acrylic copolymers are used as latex binder, and the named product with a specific external particle surface of 150-300 m ² / g is used as colloidal alumina.

The composition of the coating, the perceiving paint may include the necessary additives, such as tinting dye, optical brightener, hardener and so on.

In the proposed method, amorphous and colloidal silicon dioxide is used not as components of the individual parts of the coating, perceiving paint, but together. The use of such a mixture of pigments makes it possible to obtain a coating combining the property of high absorbency with good affinity for ink dye.

The introduction of alumina with specified characteristics allows you to further increase the fixation of the ink dye without compromising the absorption properties of the coating. The optimum is the alumina content in the range from 5 to 10% of the total pigment mass.

The introduction of alumina also makes it possible to increase the resistance of the coating, which is susceptible to mechanical stresses (the index of surface strength to plucking increased by 0.2-0.35 m / s). Thus, the resulting mixture of pigments has the following composition: amorphous silicon dioxide: colloidal silicon dioxide: colloidal alumina 80-85: 10-15: 5-10.

The paint-absorbing coating is applied in two steps in series. The total coating weight of 9-15 g / m ² . The proportion of the first layer is 30-40% by weight of the finished coating, and the proportion of the second is 60-70%. This ratio between the first and second layers is optimal from the point of view of obtaining uniform absorption properties of the coating, a durable surface and the quality of the subsequent finish.

The coating of the ink receiving coating is carried out by finishing finishing the finished paper in supercalender at a pressure in the gap of the calender rolls of 30-75 bar. The specified pressure range is optimal, an increase in pressure during calendering leads to a deterioration in the printing properties of paper due to a decrease in the porosity of the coating.

Another object of the present invention relates to inkjet paper with a pigmented coating, manufactured by the proposed method and characterized by high surface strength from 2.1 to 2.5 m / s

The proposed method for manufacturing inkjet paper is presented in Examples 1-8 below.

Example 1. A method of manufacturing paper for inkjet printing is as follows.

1. The base paper weighing 100 g / m ² receive a wet method on a paper machine using the following composition in wt.%:

Bleached Sulphate Hardwood Pulp  45-63 Bleached Sulphate Softwood Pulp  37-45 Calcium carbonate  10 (from dies, comp.) Glue AKD  0.3-0.5 (from fiber comp.) Cationic starch  0.6-1.0 (from fiber comp.) Polyamidoaminoepichlorohydrin resin  1.0-1.5 (from dies, comp.) Optical brightener  0.1-0.13 (from dies, comp.) Dye  10-12 g / t from cellulose

2. Prepare a composition with a concentration of 16% for the coating, perceiving the paint, the following composition (wt.% Dry matter by weight of the pigment):

Pigment  100 Polyvinyl alcohol  thirty Dispersion of amphoteric styrene acrylic copolymer (Raiprint)  25 Polydiallyldimethylammonium chloride (Catiofast)  7 Purple direct dye  0.01 Optical brightener  5 Polyhydroxy Resin Based Product  3

The finished mixture is applied with an air scraper in two steps.

In this case, a mixture of the following composition (wt.%) Is used as pigment: artificial amorphous silicon dioxide - 85% (trade name GASIL); colloidal silicon dioxide of cationic nature - 10 (trade name SYLOJET); colloidal alumina - 5% (trade name MARTOXIN).

The mass of the finished coating, perceiving ink, is 9-15 g / m ² . The proportion of the first layer is 30-40% by weight of the finished coating, and the proportion of the second is 60-70%. Drying of the coating is carried out using infrared emitters and by blowing with hot air (air temperature 90-130 ° C).

3. After coating, accepting ink, on the reverse side of the paper is applied anti-twisting coating having the following composition (wt.% On dry weight of the pigment):

Pigment  100 Styrene-butadiene latex  eleven Polyvinyl alcohol  2,5 Caustic soda  0.14 Tributyl phosphate  0.4 Sodium pyrophosphate  0.45

The anti-twisting coating is applied on a coating machine equipped with application units with an air scraper. The weight of the finished coating is 12-17 g / m ² . The coating is dried by blowing with hot air (air temperature 130 ° C).

After applying all the coatings, the ink-sensitive coating is refined to give it the necessary smoothness and appearance. The refinement consists in finishing the paper on a supercalender at a pressure in the grip of the calender rolls of 30 bar.

The resulting sample of inkjet paper was printed on HP DJ 6122 and Epson Stylus Photo 950 printers. The sample shows good image quality and high resistance to mechanical damage.

Example 2

A method of manufacturing paper for inkjet printing is carried out analogously to example 1 with the only difference that:

- as a cationic binder in the composition for coating, perceiving ink, use a dispersion of cationic styrene acrylic copolymer (trade name Baysize) in an amount of 20%;

- refinement is carried out at a pressure of 40 bar.

The resulting sample of inkjet paper was sealed with HP 2I 6122 and Epson Stylus Photo 950. The sample received good image quality and high resistance to mechanical damage.

Example 3

A method of manufacturing paper for inkjet printing is carried out analogously to example 1 with the only difference that:

- as a pigment in the composite composition for coating, perceiving paint, use a mixture of the following composition: artificial amorphous silicon dioxide - 80% (trade name GASIL); colloidal silicon dioxide of cationic nature - 15% (trade name SYLOJET); colloidal alumina - 5% (trade name MARTOXIN);

- refinement is carried out at a pressure of 55 bar.

The resulting sample inkjet paper was printed on HPDI 6122 and Epson Stylus Photo 950 printers.

The sample obtained good image quality and high resistance to mechanical damage.

Example 4

A method of manufacturing paper for inkjet printing is carried out analogously to example 1, with the only difference being:

- as a pigment in the composite composition for coating, perceiving paint, use a mixture of the following composition: artificial amorphous silicon dioxide - 80% (trade name GASIL); colloidal silicon dioxide of cationic nature - 15% (trade name SYLOJET); colloidal alumina - 5% (trade name MARTOXIN);

- as a binder in the composition for coating, perceiving the paint, use a dispersion of cationic styrene-acrylic copolymer (trade name Baysize) in an amount of 20%;

- refinement is carried out at a pressure of 65 bar.

The resulting sample inkjet paper was printed on HP DJ 6122 and Epson Stylus Photo 950 printers.

The sample obtained good image quality and high resistance to mechanical damage.

Example 5

A method of manufacturing paper for inkjet printing is carried out analogously to example 1, with the only difference being:

- as a pigment in the composite composition for coating, perceiving paint, use a mixture of the following composition: artificial amorphous silicon dioxide - 80% (trade name GASIL); colloidal silicon dioxide of cationic nature - 10% (trade name SYLOJET); colloidal alumina - 10% (trade name MARTOXIN);

- as a binder in the composition for coating, perceiving the paint, use a dispersion of cationic styrene-acrylic copolymer (trade name Baysize) in an amount of 20%;

- refinement is carried out at a pressure of 75 bar.

The resulting sample inkjet paper was printed on HP DI 6122 and Epson Stylus Photo 950 printers.

The sample obtained good image quality and high resistance to mechanical damage.

Example 6

A method of manufacturing paper for inkjet printing is carried out analogously to example 1, with the only difference being:

- as a pigment in the composition for coating, perceiving ink, use a mixture of the following composition: artificial amorphous silicon dioxide - 80% (trade name GASIL); colloidal silicon dioxide of cationic nature - 10% (trade name SYLOJET); colloidal alumina - 10% (trade name MARTOXIN). The resulting sample inkjet paper was printed on HPDJ 6122 and Epson Stylus Photo 950 printers.

The sample obtained good image quality and high resistance to mechanical damage.

Example 7

A method of manufacturing paper for inkjet printing is carried out analogously to example 1, with the only difference being:

- as a binder in the composition for coating, perceiving ink, use a dispersion of cationic styrene-acrylic copolymer (trade name Baysize);

- cationic polyalkylamine (trade name Cartafix) in an amount of 8% is used as an agent for improving the flexion of ink in the composition for coating an ink receptive;

- refinement is carried out at a pressure of 65 bar.

The resulting sample inkjet paper was printed on HPDJ 6122 and Epson Stylus Photo 950 printers.

The sample obtained good image quality and high resistance to mechanical damage.

Inkjet paper obtained in examples 1-7 and characterized by high surface strength from 2.1 to 2.5 m / s, which is significantly higher than paper obtained by the prototype method.

The proposed method for the manufacture of inkjet paper is characterized by a high technological process due to the exclusion of chemical refining of the coating perceiving ink, as in the prototype method, while maintaining high ink absorption and color-developing properties and improving surface strength.

Claims (4)

1. A method of manufacturing a paper for inkjet printing with a pigmented coating, comprising obtaining a base paper, coating it with an ink-containing coating, containing a latex binder, a water-soluble binder, amorphous silica-based pigment and an ink fixing agent, and then applying an anti-rolling coating to the opposite side of the base paper and the refinement of the coating, perceiving ink, characterized in that as a pigment based on amorphous silicon dioxide I use a mixture of the latter with colloidal cationic silicon dioxide and colloidal alumina with a mass ratio of these pigment components, respectively, 80-85: 10-15: 5-10, while the coating, perceiving ink, is carried out in two stages with the ratio of the weight of the coating applied to the first steps, to the mass of the coating applied in the second step, from 0.43: 1 to 0.66: 1, and the coating of the ink-perceiving coating is carried out by supercalanding it at a pressure in the grip of the supercalender shafts of 30-75 bar. 2. The method according to claim 1, characterized in that as the latex binder use aqueous dispersions of amphoteric or cationic styrene acrylic copolymers. 3. The method according to claim 1, characterized in that as the colloidal alumina use the named product with a specific external surface of the particles of 150-300 m ² / year 4. Paper for inkjet printing with a pigmented coating, characterized in that it is made by the method according to claim 1.