SU1074934A1 - Coated fibrous material - Google Patents

Description

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The invention relates to cellulose and papermaking and can be used in the production of coated paper and cardboard intended for high-quality illustrative printing.

Coated papers and paperboard containing synthetic hydrophilic polymers consisting of acrylic acid esters, acrylonitrile, (V, V-ethylenically unsaturated acids of styrene l.

The disadvantage of such materials is the low surface strength when wetted by wetting solutions in the printing process.

The most close to the invention in its technical essence and the achieved positive effect is a coated fibrous material consisting of a fibrous base and a coating coating applied to it, containing a white pigment, synthetic polymeric binder, it is based on acrylonitrile and a dispersant. The hydroxyl polymer (bonded) contained in the coating comprises, in wt.%: Acrylic acid 5-50, acrylamide 20-85, acrylonitrile 5-40. This coated material has high surface strength in both dry and wet conditions. , determined in static conditions by Denison’s toes and rubbing with the finger pT method.

However, these indicators do not fully characterize the behavior of the material in the press due to the inadequacy of the test conditions of the real printing process. The tests accepted at the present time (dynamic methods of IHT, Fogra) show insufficiently high resistance of the surface to plucking under conditions close to real ones. In addition, the coating material is not quite. satisfactory coloring due to insufficient combination of the copolymer with dispersion binders, which improve this property.

The aim of the invention is to increase the plucking resistance of the surface of the material and to improve its redness.

The goal is achieved by the fact that in a coated fiber material consisting of a fibrous base and a metal coating applied to it, containing a white pigment, a synthetic polymer binder based on acrylonitrile and a dispersant, the coating coating contains a sodium salt as a polymeric binder.

copolymer of acrylonitrile, methyl acrylate and itaconic acid with a ratio of monomers in the copolymer, wt.%: acrylonitrile 90-93, methacrylate 6-8, itaconic acid 1-2, or a mixture of it with butadiene styrene or acrylate, or vinyl acetate latex in the following ratio of coating components, pigment 100, polymeric binder 5-100, dispersant 0.3-0.4.

As a white pigment, kaolin or a mixture of it with other white pigments can be used: chalk, barium sulphate, titanium dioxide, satinweiss and others. Various phosphates can be used as a dispersant (sodium hexametaphosphate, sodium pyrophosphate, polyphosphates) Sodium polyacrylate and others.

The composition of the coating material may include other components of the coating compositions; plasticizers, optical brighteners and others.

Use of the copolymer as the sole binder in an amount less than 5.0 parts by weight. on 100 ma.ch. pigment in the coating does not provide the necessary level of indicator of the resistance of the material surface to plucking. The introduction of a copolymer of more than 100 wt. on 100 ma.ch. pigment is impractical due to the achievement of the maximum printing and technical characteristics of coated material.

The production of fibrous material according to the invention can be carried out by conventional methods for producing coated types of paper and cardboard.

Example 1 On a base paper weighing 40 g / m, a sliding scraper is coated with the following composition: May, hours: pigment (kaolin 100, copolymer 5, sodium hexametaphosphate 0.3 sodium hydroxide OD, optical brightener 0.4. Dry content The substance in the coating is 54.2%. The copolymer used contains, in wt%, acrylonitrile 92, methyl acrylate 6, and itcanoic acid 2.

Obtained after drying for 3 minutes and calendered, coated letterpress paper is tested by weight (GOST 13199-67J, whiteness (GOS 7690-76), gloss, surface durability to plucking and color perception (GOST 20807-75),

Example 2. A 250 g / m paperboard was coated with an air scraper containing, in May, h pigment (kaolin 90, chalk, chemically precipitated, 10) 100; binder copolymer 1.5 and latex styrene-butadiene-65/3, 16.5, sodium hemetaphosphate 0.4} caustic soda 0.1} optical bleach 0.4 / antifoam 0.004.

 The solids content is 44.1%. The copolymer used contains, in wt%: acrylonitrile 90, methyl acrylate 8, and itcanoic acid 2 Further operations are carried out as in Example 1.

Example 3. A paper weighing 100 g / m2 is applied successively for coating. The precoat is applied with a sliding scraper.

The coating contains, wt. H .: pigment (kaolin 50, chalk 50) lOOj copolymer 100j sodium hexametaphosphate 0.4; sodium hydroxide 0.1. The dry matter content of the coating is 14%. Used copolymer contains, wt%: Acrylonitrile 92; methyl acrylate 7; i-taconic acid 1. After drying the pre-coating, an upper layer is applied to the air scraper containing mac.ch pigment (kaolin 85, titanium dioxide is) 100, copolymer 1.0, dispersion acrylic ABB-26 14; sodium hexametaphosphate caustic 0.1 bleach 0.6, antifoam 0.04 The solids content is 41.8%. The copolymer used contains monomers in ratios the same as in the precoat. Further operations are carried out in accordance with Example 1.

Example 4. A cardboard containing, by weight by weight pigment (kaolin 90, chalk, chemically precipitated, 10) 100; copolymer 2.0; polyvinyl acetate mixture 16.6; rub hexamet-. phosphate 0.3; sodium hydroxide 0.1. The solids content is 45%. The copolymer used contains, wt%: Acrylonitrile 93; methyl acrylate 6; It is caustic acid 1. Further operations are carried out in accordance with Example 1..

Example 5. On a base paper weighing 40 g / m2 with a sliding scraper, a coating of the composition mac.h; pigment (kaolin) 100; copolymer 4; sodium hydroxide 0.1 / sodium pyrophosphate 0.3. The solids content is 59.1%. A copolymer of the composition is used as in Example 1. Further operations are carried out in accordance with Example 1.

Example b (known). On

0 80 g / m base paper with metering rolls is coated using a known copolymer as a binder. Coating composition, wt.: Kaolin 100; copolymer 10; sodium pyrophosphate 0.2; sodium carbonate 0.2. The dry matter content is 45.1%. The resulting coated offset paper is dried and subjected to tests according to the indicators described in Example 1.

Example 7 (known) A paper weighing 40 g / m is coated with a sliding scraper using a known copolymer. Coating composition, wt.: Kaolin 100; ethanol 5, O; sodium pyrofoefat 0,2 5 sodium carbonate 0,2, optical bleach 0,4. The solids content is 53.8%. The material obtained is dried and subjected to tests according to the indicators described in Example 1.

Example 8 known. A paper weighing 40 g / m is coated with a sliding scraper using a known copolymer. Coating composition, wt.: Kaolin 100; copolymer 4.0 / sodium hydroxide 0.1; sodium pyrophosphate 0.3. The solids content is 58%. The resulting coated gravure paper is dried and tested by indicators as in Example 1

The properties of the coating compositions and fibrous materials in examples 1-8 are shown in the table.

710749348

As can be seen from the table, the proposed properties by indicators

durable coated fibrous matt gloss, surface resistance to

The rial compared with limestone-plucking and color enhances printing technology.

Claims (1)

CREATED WOLF A REAL MATERIAL, Consisting of a fibrous base and a coated coating containing white pigment, a synthetic polymer binder based on acrylonitrile and a dispersant, characterized in that, in order to increase the resistance of the surface of the material to plucking and improve its paint perception, coating coating as a polymer binder contains the sodium salt of a copolymer of acrylonitrile, methyl acrylate and itaconic acid. with a ratio of monomers in the copolymer, wt.%: acrylonitrile 90-93 , methyl acrylate 6-8, itaconic acid 1-2, or a mixture thereof with styrene butadiene, or acrylate, or vinyl acetate latex in the following ratio of coating components, wt.h .: pigment 100, polymer binder 5-100, dispersant 0.3-0 ,four.