RU2334037C1 - Compound for pulp materials hydrophobisation - Google Patents

Abstract

FIELD: soft wares, paper.

SUBSTANCE: compound is intended for pulp materials hydrophobisation and can be used in pulp and paper industry and at paper and board manufacturing. Compound contains modified thallous galipot, paraffin, thallous fatty acids and balancer at defined components ratio. In the capacity of balancer sodium lauryl sulfate, sodium laureth sulfate, cocoamidopropylbetain or cocoamidopropylaminochloride is used.

EFFECT: compound refinement for hydrophobisation of pulp materials, supplying of its hydrophobization efficiency and storage life duration.

5 cl, 1 tbl

Description

The invention relates to the pulp and paper industry and can be used in the manufacture of paper and cardboard.

Closest to the claimed is the adhesive for gluing (hydrophobization) of cellulosic materials (Kermanyan Hossein. New composite adhesive for gluing cellulosic materials: Diss. ... Candidate of Technical Sciences. - M .: MGUL, 2001. - 124 p.). The composition contains unmodified tall oil rosin, distilled tall oil, consisting mainly of fatty acids with an admixture of resin acids and hydrocarbons, and cationic starch. Tall products used in this composition are technical intermediates and have a low degree of purification. However, this source mentions the possibility of using modified tall oil rosin in such a composition.

The disadvantages of this solution are: insufficiently high hydrophobic efficiency; the use of cationic starch in the adhesive composition, which significantly reduces the shelf life of the adhesive and leads to rapid biological deterioration; the use of crude (unmodified) tall oil rosin and distilled tall oil in the glue composition, which reduces the whiteness of the cellulosic material, leads to the deposition of particles of coagulated resin on the equipment, the formation of tar spots on the surface of the paper sheet (“tar difficulties”), “sticking up” (loss of hydrophobicity ) cellulosic material over time; significantly reduced mechanical strength and whiteness of the cellulosic material.

The problem solved by this invention is as follows: high hydrophobic efficiency; the possibility of using tall products in the composition without the appearance of "tar difficulties" in the formation of cellulosic material; a slight effect of the composition on the whiteness and mechanical strength of the cellulosic material; long shelf life.

The solution to this problem is ensured by the fact that the composition for hydrophobization of cellulosic materials uses tall rosin, paraffin, tall fatty acids (in the form of potassium or sodium soaps) and a stabilizer, which can be used sodium lauryl sulfate, sodium laureth sulfate, cocoamidopropyl betaine or cocoamidopropylaminochloride in the following ratio of components, wt.%:

Modified tall rosin 33-34 Paraffin 16-17 Tall Fatty Acids 33-34 Stabilizer 16-17

The technical essence of the invention is as follows:

The main hydrophobizing basis of the developed composition is modified tall rosin (modifier maleic anhydride) and paraffin. Modified tall rosin is often used for hydrophobization of cellulosic materials, however, its aqueous dispersions are difficult to prepare and have low stability, and in the form of sodium soap this rosin is not effective enough and has an increased sensitivity to water hardness salts. In the developed composition, tall modified rosin is in dispersed form. Tall modified rosin is used, produced by the Solombala Pulp and Paper Mill (Arkhangelsk).

Paraffin imparts high hydrophobicity to the cellulosic material and increases its some operational properties, but at a high content it negatively affects the mechanical strength. In addition to enhancing the hydrophobic efficiency of the developed composition, paraffin facilitates the dispersion of tall modified rosin.

Tall oil fatty acids are a mixture of unsaturated and saturated higher fatty acids of the C ₁₀ -C ₂₂ series and have an average hydrophobic efficiency with respect to cellulosic material, significantly inferior to the efficacy of tall modified rosin and paraffin. In the developed composition, in addition to the function of an additional water repellent, they play the role of a stabilizer of dispersed particles of tall modified rosin and paraffin. Tall oil fatty acids produced by Solombala Pulp and Paper Mill (Arkhangelsk) are used.

The stabilizers that can be used in the proposed composition have a very low intrinsic hydrophobic efficiency, but without them stabilization of dispersed rosin particles is impossible. Their stabilizing effect is similar to the physicochemical mechanism. To prepare the composition as stabilizers can be used:

Sodium lauryl sulfate CH ₃ - (CH ₂ ) ₁₀ -COSO ₃ Na. It has a good stabilizing effect, does not hydrolyze, does not oxidize. It is recommended primarily for use in the composition for hydrophobization of paper from 100% cellulose, for which the "whiteness" indicator is normalized.

Sodium laureth sulfate CH ₃ - (CH ₂ ) ₄ -CH = CH- (CH ₂ ) ₄ -SO ₃ Na. Its stabilizing effect is more reliable, therefore, the use implies less stringent requirements for the technological mode of preparation of the composition in comparison with sodium lauryl sulfate. It is not hydrolyzed, however, the presence of a double bond in a molecule makes it susceptible to oxidation over time. It is recommended for use in the composition for hydrophobization of paper containing wood pulp, unbleached pulp.

Cocoamidopropyl betaine is a cocaine fatty acid amine based betaine. It has a rather good stabilizing effect on rosin dispersions, is not prone to hydrolysis. Since it is produced from a mixture of various fatty acids, including unsaturated, it therefore contains impurities that are prone to oxidation over time. On the example of amidopropyl betaine stearic acid, its formula is as follows:

where R = -H;

-CH ₃ ;

-C ₂ H ₅ ;

n = most often 2-4.

Cocoamidopropyl betaine is recommended for stabilizing formulations designed to hydrophobize paper that uses recycled fiber in its composition (in combination with fresh fiber or 100%).

Cocoamidopropylaminochloride (in the form of a technical product) is a mixture of salts of tetra-substituted ammonium bases based on coconut oil fatty acid amides. The release of these highly purified products based on stearic or palmitic acids has also been mastered. Using stearic acid as an example, its formula is as follows:

Cocoamidopropylaminochloride is recommended for stabilizing formulations designed to hydrophobize paper and paperboard, produced from their secondary fibrous raw materials with a tightly closed water cycle and high cationic pulp requirements. It makes it possible to obtain dispersions with positively charged particles, which have an increased ability to deposit on a negatively charged cellulose fiber. Technical products can be used in the processing of dark waste paper, peeled - white ennobled waste paper.

The proposed hydrophobizing composition used stabilizers manufactured by Henkel, Germany.

The developed water repellent composition is a complex multicomponent dispersion, the particle sizes of which can vary from colloidal (<0.1 μm) to microheterogeneous (> 1 μm) with an average size of about 1 μm (at a concentration of 1% or less). At a concentration of> 25%, the dispersion is a solid gel with weakly expressed flow properties, which, when diluted and mixed, restores the liquid dispersed state again.

The invention is illustrated by the following example:

1. The technology of preparation of water-repellent composition in the laboratory

The components of the composition. Modified tall rosin (KTM) - 10 g (33.3%); paraffin (P) - 5 (16.7%) g; tall oil fatty acids (GIT, in the form of potassium soap) - 10 (33.3%) g; stabilizer (St) - 5 g (16.7%). As a stabilizer can be used any of the above. The type of stabilizer does not affect the ratio of the components of the composition, the technological mode of its preparation and rheological properties.

The method of preparation of the composition. The gastrointestinal tract is loaded into a pre-weighed glass of 250 ml, add about 150 ml of distilled water, put in a water bath, include heating and stirring using a mechanical stirrer. The temperature in the glass should gradually increase (10 min).

Then saponification is carried out, loading solid KOH in the same glass in the amount necessary for complete saponification of the GIT (CK for the GIT we take 200 mg KOH / g). In practice, for complete saponification of the GIT, an excess of KOH of about 20% is necessary due to the partial hydration of KOH and its transition to K ₂ CO ₃ when stored in air, as well as the hydrolysis of salts formed during saponification. The pH value of the solution completely washed away GIT should be about 8.0 ... 8.5 (blue-green color universal indicator paper). After this, St is introduced into the glass, and the temperature in the glass is brought to 85 ... 90 ° C (15 min).

A mixture of solid KTM and P is placed in a porcelain container and heated in an open flame until the components are completely melted to form a homogeneous oily melt (t≈120 ° С). The melt is gradually introduced into a glass with saponified GIT and St. Abrupt entry of the entire mass of the melt can lead to boiling of the mixture and its splashing through the walls of the glass (10 min).

After 1 ... 2 min after entering the mixture of KTM and P, a uniform yellow-brown dispersion forms in the glass. Then it is intensively mixed at a temperature of 85 ... 90 ° C for at least 40 minutes. This is necessary for the formation of a homogeneous dispersion (45 min).

To obtain the dispersion of the required concentration (25% or more), it is evaporated under the same conditions (see above). Usually, evaporation is stopped with a strong increase in the viscosity of the dispersion, which makes it difficult to further mix it (at C> 30%) (1 ... 2 h).

Upon reaching a certain dispersion viscosity (mixing is still possible, but already becoming difficult), the heating is turned off, hot water is drained from the water bath, and then it is filled with cold water. After 5 minutes, the operation is repeated (only 4-5 times). This is necessary for the gradual cooling of the finished dispersion. The process is completed at a temperature of the finished dispersion of about 35 ° C (30 min).

The total duration of the process is about 3 ... 4 hours (depending on the required concentration of the finished composition).

2. The technology of using hydrophobizing composition in paper production

Offset paper No. 1 was produced with a weight of 70 g / m ^{2 and an} ash content of 10% with the following fiber composition: bleached softwood sulphate pulp - 50%, grinding degree - 30 ° SR; hardwood bleached pulp bleached - 50%, grinding degree - 32 ° SR. Production of offset paper No. 1 on a laboratory sheet-sieving apparatus includes the following steps:

1. Dissolution of the fibrous material (cellulose) in water with the formation of a water-fiber suspension.

2. Introduction to a water-fiber suspension of a mineral filler (kaolin).

3. Introduction to the aqueous-fiber suspension of chemical additives in the following sequence and with the following dry matter costs: cationic starch - 5 kg / t; water-repellent composition (or composite glue - the closest analogue) - 10 kg / t; aluminum sulfate - 30 kg / t.

4. Adjustment of the pH of the aqueous fiber suspension by the addition of sulfuric acid or sodium hydroxide to the desired value (pH 6.5).

5. The formation of the paper web, which consists in filtering a water-fiber suspension through a grid of a sheet-forming apparatus with the formation of a wet paper web on a grid.

6. Pressing the paper web, consisting in the mechanical extraction of water from it using a special roller.

7. Drying the paper web at a temperature of about 95 ° C for 7 minutes.

The properties of offset paper made using the proposed composition and the closest analogue are presented in the table.

Table Offset Paper Properties The composition for processing Name of indicator Breaking length, m The degree of sizing, mm Surface Absorption, g / m ² Moisture resistance,% Plucking, m / s Kink No chemicals 4000 0.2 70 5 2.0 four Suggested composition 3900 2.0 10 8 2.2 four The closest analogue 3700 1.75 fourteen 6 1.8 3

The data in the table indicate that the use of the developed water repellent composition does not have a pronounced negative effect on the physicomechanical properties of offset paper. With a slight decrease in the breaking length, the surface resistance to plucking increases slightly, which is important for offset printing.

When using the closest analogue, its negative effect on all the basic properties of offset paper is much more pronounced. The proposed new gidrofobiziruyuschey composition will maximize eliminate this negative impact and improve the paper-making process.

Claims (5)

1. Composition for hydrophobization of cellulosic materials, including modified tall rosin, paraffin, tall fatty acids, characterized in that the composition further comprises a stabilizer in the following ratio of components, wt.%: Modified tall rosin 33-34 Paraffin 16-17 Tall Fatty Acids 33-34 Stabilizer 16-17 2. The composition according to claim 1, characterized in that sodium lauryl sulfate is used as a stabilizer. 3. The composition according to claim 1, characterized in that as a stabilizer use sodium laureth sulfate. 4. The composition according to claim 1, characterized in that cocoamidopropyl betaine is used as a stabilizer. 5. The composition according to claim 1, characterized in that cocoamidopropylamino chloride is used as a stabilizer.