WO1998033971A1 - Use of alkylpolyglycosides for deinking wastepaper - Google Patents

Abstract

Alkylpolyglycosides having the general formula (I): R(G)x, in which R stands for a linear, saturated alkyl radical with 8 to 22 C atoms and (G)x for a glycoside or oligoglycoside radical with an oligomerisation degree x from 1 to 10, are particularly suitable for deinking wastepaper.

Description

 "Use of alkyl polyglycosides for deinking waste paper"

Field of the Invention

The invention relates to the use of alkyl polyglycosides for deinking waste paper.

State of the art

Waste paper is now used in large quantities to produce newspaper and hygienic paper, for example. For these types of paper, brightness and color are quality features. In order to achieve these quality features, the printing inks must be removed from the printed waste paper. This is usually done using the so-called deinking process. These processes are carried out in technically customary plants for processing waste paper, which are provided with additional devices for separating the detached ink particles. There are two important steps:

(1) The opening of the waste paper: This is the process of shredding the waste paper. For example, it can be induced in an aqueous medium by adding mechanical energy (stirring). The fraying is accompanied by the detachment of the ink particles. These particles disintegrate into very small particles with a particle size of 0.1 to 1,000 μm and are in finely dispersed form. When opened, a paper stock suspension in the form of a gray paper pulp is obtained.

(2) Removal of the detached ink particles from the paper stock suspension: This step of the deinking process can be carried out by washing out or by flotation. The flotation deinking process is of particular importance. In general, fatty acids or soaps are used as ink collectors in Central Europe.

In modern processing plants, additional process steps such as multi-stage flotation, dispersion, bleaching stages, thickening and water purification are also integrated (cf. e.g .: Wochenblatt für Papierfabrikation 1996 (21) pages 929 to 935).

Waste paper is also increasingly used for the production of higher quality paper types, such as graphic paper and SC paper, or as a replacement for cellulose. In addition to brightness and color, the purity of the deinked material is an additional criterion. The number and specific area of dirt spots can be regarded as a measure of the purity.

In order to achieve the use of larger quantities of waste paper in the production of higher-quality paper types for ecological and economic reasons, the dirt point removal with the known collector systems is not sufficient in many cases.

A number of surface-active substances are known from the patent literature as flotation collectors for deinking waste paper. In addition to fatty acids and soaps, alkoxylated fatty alcohols or fatty acid polyglycol ethers are mainly used used. In addition, other nonionic compounds with very different chemical structures are described.

The use of alkyl polyglycosides to deink waste paper and in particular to remove dirt spots from waste paper is not known from the literature to date. The use of formulations containing alkyl polyglycosides for general or special paper-technical applications is generally known, for example their suitability

- for paper production (from WO 92/2284),

as an additive in papermaking (DE-A-40 26 617),

- for coatings on heat-sensitive printing papers (Chemical Abstracts 114: 145733),

- for the production of lime suspensions in paper production (DE 39 01 12),

for the production of tissue paper with improved softness (EP-A-347 177 and EP-A-347 176),

as a drying aid and as a coating agent for paper (WO 89/2907),

- As an anti-agglomeration aid, inter alia, for the paper industry (WO 89/2912), but this prior art does not prescribe or suggest the subject matter of the present invention.

Description of the invention

The object of the present invention was to provide new collectors or collector mixtures which enable a high flotative discharge of dirt spots. Surprisingly, it has been found that alkyl polyglycosides, which belong to the class of nonionic surfactants, alone or in combination with other collectors, are suitable for the sustainable removal of dirt spots from waste paper.

The present invention therefore relates to the use of alkyl polyglycosides (I)

R (G) _x (I)

wherein R is a linear, saturated alkyl radical with 8 to 22 carbon atoms and (G) _x a glycoside or oligoglycoside radical with a degree of oligomerization x of 1 to 10, for deinking waste paper.

Alkyl glycosides of the given formula (I) have long been known surface-active substances which can be prepared from sugars and aliphatic, primary alcohols with 8 to 22 carbon atoms with acetalization. Preferred sugar components (glycoses) are glucose, but also fructose, mannose, galactose, telose, gulose, allose, old rose, idose, arabinose, xylose, lyxose, libose and mixtures thereof.

The acetalization products of glucose with fatty alcohols, which are obtainable, for example, from natural fats and oils by known processes, in particular with linear, primary, saturated and unsaturated fatty alcohols having 8 to 22 carbon atoms, are preferred because of the easy accessibility and the good application properties.

Regarding the glycoside residue (G) _{x, it} applies that both monoglycosides (x = 1), in which a sugar residue is glycosidically linked to the fatty alcohol, as well as oligo- mere glycosides with a degree of oligomerization x = 2 to 10 are suitable. As a rule, mixtures of mono- and oligoglycosides are present.

Those alkyl glycosides (I) in which R is an alkyl group having 8 to 22 C atoms and (G) _{x is} a glycoside or oligoglycoside residue with a degree of oligomerization x = 1 to 10 are particularly suitable. R is very particularly preferably an alkyl group having 8 to 14 carbon atoms. The average degree of oligomerization is preferably in the range from 1 to 1.5.

In many cases, the extent of the removal of printing inks from printed wastepaper can be increased when the inventive alkyl polyglycosides in combination with, for example, Ci0-22 "F ^eu acids or their alkali metal or alkaline earth salts of C6_22 ethoxylated alkyl alcohols, ethoxylated alkyl phenols, cationic polymers, eg polydimethylaminomethacrylate and / or copolymers, the total amount of these optional components is between 0.05 and 1.0% by weight, based on air-dry paper stock.

In the presence of the alkyl polyglycosides to be used according to the invention, printing inks, for example newspaper printing inks, letterpress inks, offset printing inks, illustration gravure inks, flexographic inks, laser printing inks and / or packaging inks from printed waste papers, for example newspapers, magazines, computer papers, magazines, brochures, forms, telephone books and / or catalogs remove. The waste papers which are deinked in the presence of the alkylpolyglycosides to be used according to the invention are distinguished by high degrees of whiteness and good removal of dirt spots.

The following examples serve to explain the invention and are not to be understood as restrictive. Examples

Substances used

Glucopon 215:

50% aqueous solution of alkyl polyglycosides based on a native Cg.i Q fatty alcohol ("Glucopon 215 CS UP"; Henkel KGaA, Düsseldorf)

Glucopon 600:

50% aqueous dispersion of alkyl polyglycosides based on a native Cj2- ₁₄ fatty alcohol ( "Glucopon 600 CS UP / HH."; Product of Henkel KGaA, Dusseldorf)

SP 85/61:

1225 g (7.9 mol) of preliminary fatty acid (60% Cg, 35% Cio, acid number = 361.9) were introduced. The mixture was then heated to 150 ° with stirring and 1770 g (7.5 mol based on epoxy-0) of soybean oil epoxide (epoxy-0 = 6.78) were added within 1 hour. After the addition had ended, the temperature was slowly increased to 170 ° C. and after 2 hours (epoxy-0 <0.15%) and distilled in vacuo at 200 ° C. (469 g distillate). The end product was a yellow, clear polyol (viscosity = 5550 mPas; 20 ° C, OH number = 105, saponification number = 236, acid number = 3.1). 423 g (39 parts) of this reaction product of soybean oil epoxide with preliminary fatty acid were mixed with 6.9 g of a 30% solution of potassium hydroxide in methanol and heated to 100 ° C. in an autoclave. At this temperature, the traces of methanol were removed by evacuating 5 times and venting with nitrogen as a protective gas. After the reaction temperature had been raised to 150 ° C., a total of 660 g (61 parts) of ethylene oxide were metered in in portions so that the pressure in the reactor did not exceed 5 bar. After the reaction was cooled to 80 to 100 ° C and about to remove traces of ethylene oxide Evacuated for 15 minutes and neutralized with lactic acid. The product obtained, SP 85/61, was a clear, yellow liquid (OH number = 54.7).

example 1

Paper: artificial office waste mixture of: 35% copy paper 35% laser paper (HP-Laserjet II / III) 30% merchandise (Hermes, sorted) All papers were naturally aged.

Pulper: paper mass: 110 g (air dry)

Water: 0.44 1/7 ° dH

Time: 15 min.

Temperature: 45 ° C

Chemicals: alkaline "reduced" "neutral"

Water glass: 2.0% 1%

H202 (100%): 0.7% -

NaOH (100%): 1.0% 0.75%

Unstuck: water: 2.54 1/7 ° dH

Time: 5 min.

Temperature: 45 ° C

Fabric density: 4%

RPM: 1865 Bütte: water: 2.54 1/7 ° dH

Time: 90 min.

Temperature: 45 ° C

Fabric density: 4%

Flotation: Denver cell: 9 1

Fabric density: 1%

Fabric temp .: 45 ° C

Duration: 8 min.

Collectors used:

Collector B 1 (for comparison) stearic acid ("Olimor 4020"; Fa. Henkel KGaA, Düsseldorf)

Collector AI Glucopon 600

Collector A2 70% SP 85/61

30% Glucopon 600

Collector A3 95% SP 85/61 5% Glucopon 600

Example 1.1:

Glucopon 600 was used alone and in combination with SP 85/61 as the compound according to the invention. For comparison, stearic acid (collector B1) was used. The collectors were each used in the pulper in an alkaline formulation. The dosage in percent is based on the waste paper used. The results of the white and dirt spot measurement after flotation are summarized in Table 1. When using the collector AI-A3 according to the invention, the dirt spot area was reduced significantly more when using the comparative collector B 1.

Table 1: Pulp dosage (alkaline recipe)

Remissionswert bei 457 nm (nach Flotation)

Reflectance value at 457 nm (after flotation)

Example 1.2

As the compound according to the invention, Glucopon 600 was again used alone and in combination with SP 85/61. For comparison, stearic acid (collector B1) was used. The collectors were used in the pulper with a reduced recipe. The dosage in percent is based on the waste paper used.

The results of the white and dirt spot measurement after flotation are summarized in Table 2. When using the collector AI -A3 according to the invention, the dirt spot area was reduced significantly more than when using the comparative collector. Table 2: Pulp dosage (reduced recipe)

Remissionswert bei 457 nm (nach Flotation)

Reflectance value at 457 nm (after flotation)

Example 1.3

Glucopon 600 in combination with SP 85/61 was used as the compound according to the invention. For comparison, stearic acid (collector B1) was used. The collectors were used in the cell directly before the flotation without any additional chemicals ("neutral" recipe). The dosage in percent is based on the waste paper used.

The results of the white and dirt spot measurement after flotation are summarized in Table 3. The mixture containing Glucopon 600 reduced the dirt spot area significantly more than the comparison collector.

11

Table 3: Cell dosing at neutral pH

Remissionswert bei 457 nm (nach Flotation)

Reflectance value at 457 nm (after flotation)

Example 2

Collectors used:

B2 collector (for comparison) SP 85/61

A4 Glucopon 215 collector

Collector A5 90% SP 85/61 + 10% Glucopon 600

Collector A6 85% SP 85/61 + 15% Glucopon 600

Collector A7 Glucopon 600

Collector A8 90% SP 85/61 + 10% Glucopon 600

Collector A9 85% SP 85/61 + 15% Glucopon 600

Test conditions: Paper: 100% office waste (merchandise)

Open: Quantity of paper: 110 g

Water: 0.44 1.7 ° dH

Time: 15 minutes

Temperature: 45 ° C

Fabric density: 20% Unstuck: water: 2.54 1, 7 ° dH

Time: 5 minutes

Temperature: 45 ° C

Fabric density: 4%

Chemicals: Alkaline formula:

Water glass: 1.0%

H ₂ O2 (100%): 0.38%

NaOH (100%): 0.38%

Neutral formula: without chemicals

Collector / surfactant: 0.15% total

Adding pulper

Bütte: exposure time: 90 minutes

Exposure temperature: 45 ° C

Flotation: Volume: 9 1

Fabric density: 1%

Fabric temp .: 45 ° C

Duration: 8 minutes

Example 2.1

Glucopon 600 and Glucopon 215 (alone and in combination) were used as the compound according to the invention. A nonionic collector was used for comparison. The collectors were used in the pulper with an alkaline recipe. The dosage in percent is based on the waste paper used. 13

The results of the white measurement after flotation are summarized in Table 4. Mixtures containing alkyl polyglycosides (APG) increase the whiteness significantly more than the reference collector.

Example 2.2

By using APG and APG mixtures, the dirt spot area was also greatly reduced. This is shown in Table 5 using the example of neutral flotation for the important dirt spot size range from 200 to 250 μm.

Table 4: Flotation of offϊce waste dealer mix (alkaline recipe)

Remissionswert bei 457 nm vor Flotation

Remission value at 457 nm before flotation

2 Remission value at 457 nm after flotation O 98/33

14

Table 5: Flotation of office waste dealer mix (neutral recipe)

Claims

claims 1. Use of alkyl polyglycosides of the general formula (I) R (G) _x (I) wherein R is a linear, saturated alkyl radical with 8 to 22 carbon atoms and (G) _x a glycoside or oligoglycoside radical with a degree of oligomerization x of 1 to 10, for deinking waste paper. 2. Use according to claim 1, wherein R is an alkyl group having 8-14 carbon atoms. 3. Use according to claim 1 or 2, wherein x is in the range of 1 to 1.5. 4. Use according to one of claims 1 to 3, wherein G is a glucoside residue.