SU649331A3 - Paper coating composition - Google Patents

Description

This invention relates to polymeric compositions used as coatings, for example, for paper. A composition for coating paper based on vinyl esters of carboxylic acids and related additives is known. This composition is highly viscous, which does not provide good quality coverage. 1. The closest to the proposed composition of the technical nature is a paper coating composition, including casein or starch, a synthetic binder, pigments, an emulsifier, a pigment dispersant and water (2). However, this composition has low rheological properties, and the finished coating has low physicomechanical properties. The purpose of the invention is to reduce the viscosity of the composition and increase the resistance to fiber separation. This is achieved in that the composition, including casein or starch, pigments, emulsifier, dispersant for pigments and water, as a binder contains a copolymer of 70-95 wt.% Vinyl acetate and 5-30 wt.% Ethyl acrylate and / or vinyl ester of unbranched monocarboxylic acids, and as an emulsifier - a mixture of 5-95 wt.% sulfonated product of the interaction of 1 mol of alkylphenol with an unbranched or branched alkyl residue with 6-20 carbon atoms with 2-8 mol of ethylene oxide or propylene oxide and 5-95 wt.% of product interactions 1 mole an unbranched or branched alkyl residue with 6-20 carbon atoms with 1-40 mol of ethylene oxide or propylene oxide and / or a compound of the general formula HO- (CH2-CH.jo- | g- {CH-CHj-O-Y (CH ., - CH, -O-) H, where 01 is 2-40, s-2-40, with the following ratio of the components of the composition, wt.% Casein or starch 2.5-20 Synthetic binder 1-15 Emulsifier0 , 02-0.45 Pigments25-47.5 Dispergator for pigments 0.05-0.15 Water Else.It was found that significantly improves not only the stability of the mass of paper dp, paper, especially shear resistance, but also resistance to windows from the surface of the obtained coated paper without adverse changes in the viscosity of the pulp for pulp containing starch, if additionally introducing vinyl sulfonic acid or / and styrene sulfonic acid in an amount of 0.1–5%, preferably about 2S, into the copolymer from about 1.5%, wears monomerically mixtures, however, the use of these compounds in polymer dispersions, together with their significantly improved stability, significantly improves the resistance to the separation of fibers from coated paper without this having a harmful effect. the rheological properties, especially when using a natural starch as a binder, as SOMO rooms with vinyl acetate or vinyl propionate is used neraevetvlennoy higher ester of a monocarboxylic acid having up to 12 carbon atoms or etilakrylat or a mixture thereof. The quantitative ratio of vinyl acetate to comonomer may be 70: 3095: 5, preferably 80: 20-90: 10. By higher vinyl) shea ethers, it is meant, for example, vinyl butyr vinylcapronate, vinyl laurate. Redox systems of ammonium or alkali metal sulphate peroxides and ammonium or alkali metal sulphates or ascorbic acid are preferably used as catalysts for polymerization. All components of the reaction can be emulsified to obtain a dispersion. A part of the emulsion is loaded into the reaction vessel, the redox-system peroxide is added and the mixture is heated to the reaction temperature. The rest of the emulsion is mixed with the second component of the redox system and. this mixture is introduced continuously. One of the main problems when using a polyvinyl acetate dispersion is that the mass prepared for coating paper when mixing is done, the collapse of small as a natural binder has too high viscosity and therefore cannot be processed with modern high-speed coating machines. In contrast, the masses for papermaking, which were obtained according to the proposed method and contain a polyvinyl acetate dispersion, are weakly with a solids content above 50%. The viscosity does not change much after 24 hours. In addition, the coating masses are resistant to (resistant to storage and to electrolytes. First of all, they are resistant to shear stress. Therefore, they are especially suitable for treating with rollers and doctor blades for coating. The coating masses are mainly 25-55 % solids. The proportion of copolymer 2-; 30%, the pigment content of the filler 50-95% of the total amount of solids contained in the mass for coating. The mass for coating paper may consist of natural bonds up to 40% soluble starch or casein or mixture and these substances (relative to the solids content). Used fillers that are added to the coating mass include kaolin, Chinese alumina, barium sulphate, calcium carbonate, titanium dioxide, etc. Coatings contain a dispersant for pigments and may include an optical brightener, defoamer, wax or plasticizer. Polyacrylic acid salts, high molecular weight water-soluble polyphosphates, are used as dispersants. s weight paper coating when using dispersions which are structured as follows. Dispersion A: 50% aqueous copolymer dispersion of 600 parts by weight vinyl acetate and 148 weight.h. vinyl propionate, obtained by applying 11.3 parts by weight. reacted with 2 moles of ethylene oxide and then sulfonated octylphenol and 8.4 parts by weight. 8 moles of reacted ethylene oxide, nonylphenol, as emulsifiers and a 1 -mino peroxydisulfate, and potassium, and sodium bisulfite as a catalyst. Dispersion B: 50% water copolymer dispersion of 600 parts by weight vinylacetate and 148 weight, h: h of ethyl acrylate with the same emulsifiers and catalysts as in dispersion A. Dispersion B: 50% aqueous copolymer dispersion made from 600 weight parts, vinyl acetate and 148 weight parts. vinyl propionate. The mixture of emulsifiers: 11.3 weight.h. reacted with 6 moles of ethylene oxide and then sulfonated octylphenol and 8.4 parts by weight. octylphenol reacted with 40 moles of ethylene oxide. Dispersion G: 50% aqueous copolymer dispersion of 600 parts by weight vinyl acetate and 148 weight, h. vinyl propionate. Emulsifiers: 11.3 weight.h. reacted with 2 moles of ethylene oxide and then sulfonated nonylphenol and 8.4 parts by weight. an emulsifier of the general formula HO- (CH2-CH2-O-) Q- (CH-CH2-0 -) - (CH2-CH., CH3 with 10% polyoxyethylene, and the palioxypropylene contained in it has IHL I 1750,

Example 1

A. The pigment disperser is dissolved in 50 parts by weight of water. With rapid stirring, 100 parts by weight of Chinese alumina are mixed in. After this, 10 parts by weight are added. 20% starch solution at room temperature (dissolved at 80-90 s). From this lime is prepared from 10 weight, h. A-D dispersions and water for coating paper with a solids content of 45% by weight.

The results are shown in table 1.

B. 45% by weight for coating is obtained from 5 parts by weight. one of the dispersions B, c, D and 15 weight parts. starch according to example 1A.

The results are shown in table 2.

Example 2. From the dispersion D and G according to example 1L, a mass is obtained for Coating with a solids content of 50% by weight.

The results are shown in Table. 3

Example 3. A casein mass for coating with a content of 50% solids is obtained from the following components: 70 parts by weight Chinese clay, 30 weight.h. calcium carbonate, 5 weight.h. casein, 12.5 weight.h. polymer dispersion L or B. Before mixing with sodium hydroxide solution casein is boiled for 30 minutes at. The pH value for coating is adjusted to 9 with sodium hydroxide solution.

The results are shown in table 4.

Coating paper is coated with a coating mass at the rate of 9 g / cm. The coated paper is satinized with a supercalender and then kept for 24 hours at 65% relative humidity. The ability to bind the filler is measured on a test printing press of the Institute of Printing Technology (Netherlands).

The results are shown in table.5.

Preparation of dispersions.

In a stirring mechanism in water, emulsifiers of mixtures of emulsifiers and monomers given in table 6 are emulsified. 100 weight.h. this mixture is loaded into the polymerization markings apparatus, add 2 weight.h. ammonium persulfate and heated to. The main part of the emulsion is mixed with 2 weight.h. sodium bisulfite. The mixture is added to the pledged amount over 90 minutes, and the temperature is slowly raised to. At the end of the addition, the temperature is slowly raised to and finally held for another 30 minutes while blowing air over it.

Table 6 uses the following notation.

Emulsifiers 1-6 g

1. Octylphenol, substituted with 2 moles of ethylene oxide and then sulphonated.

2 .. Octylphenol, substituted with 16 moles of ethylene oxide and then sulphonated.

3. Octylphenol, substituted with 6 moles of ethylene sulfide and then sulphonated.

4. (onylphenol, substituted with 8 moles of ethylene oxide.

5. Octylphenol, substituted with 40 moles of ethylene oxide.

b. Pleuronic 61 Weandot Chemicals: emulsifier containing 10% polyoxyethylene and polyoxypropylene, and part of the polyoxypropylene has a weight of 1750.

Monomers:

VA - vinyl acetate; VP - arylpropionate; EA - Ethyl lactylate, NV5 - Sodium Vinyl Sulfonate.

Example 4

Composition a. The dispersion medium for the pigment is dissolved in 50 parts by weight.

5 water. In a high-speed stirring apparatus, 100 weight parts are measured. kaolin. 10 parts by weight are then added at room temperature. 20% pacfora starch (kneaded at 80-90 0.

0 From this mass take 10 weight.h. dispersions and an appropriate amount of water and is used as a paper coating compound.

Composition b. Coating Compound

5 is prepared from 5 parts by weight, dispersions and 15 parts by weight. starch in example 1A.

Composition with. The casein composition is composed of a solid content of the following components:

0 70 weight.h. kaolin, 30 weight.h. calcium carbonate, 5 weight.h. casein, 12.5 weight.h. polymerized dispersion. Casein before seshivaniem incubated for 30 min with soda alkali

5 at 50s. The composition for coating was adjusted to pH 9 with soda base.

Coating paper is coated with a coating compound, the flow rate being 9 g / m.

0 Coated satin paper on a supercalender and, in conclusion, kept for 24 hours at 65% relative humidity. The ability to take pigment is measured by

5 printing device for test printing OST. The values obtained are a relative measure of the ability to take pigment.

The results obtained with various compositions for coating paper are listed in Table 7.

Table 1

Table 6

Claims (2)

TABLE Note: Formula of the Invention Composition for paper coating, including casein or starch, a siitichesky binder, pigments, emulsifier, dispersant - for pygmies and water, excellent strength, in order to reduce the viscosity of the composition and increasing the separation resistance of the fibers as a synthetic binder, it contains a copolymer of 70-95% by weight of vinyl acetate and 5-30% by weight of ethyl acrylate and / or vinyl ester; unbranched monocarboxylic acids. As an emulsifier, a mixture of 5-95% by weight of a sulphonated product reacts with 1 mol of alkylphenol. the mole of alkylphenol with non-branched BPC or branched FKR solids content; FORD 4 - FORD-BECHER О 4 / 20С; BROOKF - reaction viscometer BROOKF3ELD, X - dispersion according to THEY patent No. 3282866 spindle speed -5100 rpm; (for comparison). an alkyl residue with 6-20 carbon atoms with 1-40 mol of ethylene oxide or propylene oxide and / or compounds of the general formula HO- (CH2-CH.j-0-7a-CCH-CVO-V V 2-3 cM. where 2 40, , cs2-40, with the following ratio of all components of the composition, wt.%: Casein or starch 2.5-20 Synthetic binder 1-15 Emulsifier 0.02-0.45 Pigments 25 -47.5 Disperser for pigments 0.05 -0.15 Water. Others. Sources of information accepted for review during examination. - 1. French Patent No. 1497368, Cl, D 21 N, 1971. 2. US patent W 3282866, cl. 260-8, 1966.