DE19916078A1 - Enhancement of whiteness, lightness and color of fibrous materials, inorganic fillers, pigments and binders for paper manufacture and finishing uses water-soluble copper phthalocyanine complex as photoactivator - Google Patents

Abstract

In a process for improving the degree of whiteness, lightness and color position of (a) fibrous materials, (b) inorganic fillers and pigments and (c) binders for paper manufacture and finishing, by adding water-soluble phthalocyanine photoactivator(s) to (a), (b) and/or (c), the activator is a water-soluble copper phthalocyanine complex (I). An Independent claim is also included for mixtures produced in this way from (I) and (a) fibrous materials, (b) inorganic fillers and pigments and (c) binders for paper manufacture and finishing.

Description

The invention relates to a method for improving Whiteness, brightness and color locus of (a) fibers, of (b) inorganic fillers and pigments, as well as (c) Bin for papermaking and finishing, with the to be treated substances (a), (b) and / or (c) at least a water-soluble phthalocyanine photoactivator added becomes.

From EP 0 588 767 B1 a method for the improvement of Whiteness, brightness and color of wood pulp or de ren mixtures by the addition of water-soluble phthalo cyanines known as photoactivators. As photoactivators are preferably the phthalocyanine complexes of aluminum, Zinc, magnesium, calcium, iron, sodium or potassium or the manganese used.  

The phthalocyanine metal complexes have the formula

wherein MePc is the phthalocyanine ring system mentioned above th metals, Y is hydrogen, an alkali metal or ammonium, v any number from 1 to 4, R is fluorine, chlorine, bromine or iodine and x is any number from 0 to 8.

A similar subject, namely a method of verbs rating of whiteness, brightness and color of white, anor ganic fillers, pigments or mixtures thereof writes EP-0 588 768 B1. This procedure is a water-soluble phthalocyanine photoactivator or a mixed from water-soluble phthalocyanine photoactivators to the Fillers, pigments or mixtures thereof given. The Phthalocyanine photoactivators correspond to those of EP-0 588 767th

The invention was facing these documents the task based, the above properties on a economic way to improve.

The inventive method is thus characterized net, that as a water-soluble phthalocyanine photoactivator used a water-soluble copper-phthalocyanine complex.

Surprisingly, it was found that the water-soluble Copper phthalocyanine complex even with a reductive lead chung has a lightening effect, probably on the Activation of the remaining residual oxygen is based. The Copper phthalocyanine complex can also be used in the oxidative  Bleaching can be used. The inventive method is also very economical, since the copper phthalocyanine complex considerably cheaper than the corresponding aluminum phthalo cyanine complex is.

Compared with the methods of the above References, the copper used in the invention is Phthalocyanine complex also for the treatment of organic Binders suitable for paper production.

According to a preferred variant according to the invention min least one copper phthalocyanine complex of the formula

where CuPc is the copper phthalocyanine ring system, Y Hydrogen, an alkali metal or ammonium, v 1 to 5, R is fluorine, Chlorine, bromine or iodine and x is 0 to 8.

Particularly preferred to use according to this variant Copper phthalocyanine complex of formula (I) wherein Y is water substance, potassium or sodium, v 2 to 4, R is chlorine or bromine and x is 0 to 2

The copper-phthalocyanine complexes of the formula (I) are present in an ionic form. Preferably, however, water-soluble cationic copper-phthalocyanine complexes are used after a second pretreatment, when the substances to be treated have a negative surface charge, because in this way better bonding with the fibers, fillers or pigments or binders takes place. The cationic copper phthalocyanine complexes have the general formula

wherein CuPc the copper phthalocyanine ring system, R is fluorine, chlorine, bromine or iodine, x 0 to 8, R ₁ , R ₂ , and R ₃ independently of one another alkyl groups having 1 to 18 carbon atoms or aryl, aralkyl or alkaryl groups, n to 18 and y is 1 to 5. Preferably, at least one of R ₁ , R ₂ and R _{3 is} a lower alkyl group of 1 to 5 carbon atoms.

The water-soluble cationic copper phthalocyanine complexes can also be prepared by the compounds of the formula (I) with substances which are quaternary positively charged Contain nitrogen atoms. The number of quaternary nitrogen atoms and thus the charge density is constant over the entire pH range.

The copper phthalocyanine complexes used in the invention probably work by activating the in the bleaching systems always available atmospheric oxygen in Ge present of light, in particular of UV light. It became though also found that activation by supply of Heat energy or mechanical energy takes place.

Copper phthalocyanine complexes are known per se (cf. Rompp Lexikon Chemie, 10th edition, 1998, page 3324), wherein only their properties were used as dyes. Water-soluble copper-phthalocyanine complexes are included For example, in the paper industry as Nuancierfarbstoffe used. Especially the group of basic dyes is as Nuancierkomponente widespread (E. Wenderoth, B.  Hunke, Alternative Weißnuancierung, PTS Symposium Chemical Technology 1992, Munich).

These dyes thus do not exert any bleaching effect.

As fibrous materials (a), for example, wood pulp, cell fabric, waste paper Textile pulp Pulp derivatives or their Ge be used. Examples of wood pulp are cut (GW), pressure ground (PGW), refiner (RMP), thermomecha chemical (TMP) and chemical-thermo-mechanical (CTMP).

For the brownish-yellow color of the unbleached wood pulp are essentially lignins, lignin-like phenols and Ex tractors and their degradation products. At the Bleaching, the chromophore system is chemically altered, is but still present, so that the color effect after a ge know time can come again. This is the reason for the high yellowing tendency of wood pulp containing paper.

In many cases, the bleaching of wood pulp, despite high H ₂ O ₂ - concentrations, the required whiteness is not reached, so that an additional reductive bleaching z. B. must be performed with sodium thionite. This two-stage process he not only demands an increased cost, but also disturbs the still existing H ₂ O ₂ whose biocidal effect is then no longer present in papermaking.

Examples of pulp are sulfite and sulfate pulp.

Examples of waste paper are daily newspapers, magazines, Packaging material, cardboard boxes, etc.

In the case of waste paper bleach, the paper suspension becomes a flo tations-Deinken subjected. Here are the hydrophobic Fabrics (waxes, plastic binders) as well as the printing inks floated out. After deinking is a so-called "gray  For example, colored impurities (chromophores) are colloidally dissolved substances (printing ink components, adhesive etc.).

Examples of fabric are cotton and linters.

Examples of pulp derivatives are xanthate, copper silk and acetate silk.

The fillers and pigments used according to the invention (b) Can be used in the paint, paints, ceramics, rubber and plastic production are used. The largest amounts of whitetip However, they are used when painting paper. The Pigments form the actual "body" of the stroke. Since she, with a few exceptions, 80% to 95% of the total dry spread weight, they determine in high Measure the quality and especially the whiteness of the stroke.

Examples of fillers and pigments (b) are aluminum silicates, such as kaolin, bentonite, mica or talcum, magnesium silicates, mixed aluminum-magnesium silicates, calcium carbonate, such as calcite, aragonite, marble, chalk or limestone; calcium sulfate, such as gypsum; Titanium dioxide or mixtures thereof.

The naturally occurring fillers and pigments like Kaolin, natural calcium carbonate (eg chalk and marble) and talc often do not correspond to the high white degree requirements. Admixtures of strong coloring Substan zen, like colored minerals or humic acids, can change the white strongly influence negatively.

When bleaching fillers such as kaolin, the or ganic impurities (humic acids) are removed. It be z. As zeolites (carriers) or wetting agents, such as PVP or PEG (polyethylene glycol) with copper phthalocyanine used, wherein a certain pH is adjusted.  

Examples of organic binders for papermaking (c) are starch or carboxymethylcellulose. The strength is in generally yellowish by proteins. Usually will use corn starch and potato starch as binders det. The strength is added to the other coating color components give. It can also be used for size presses and also serves to improve the strength by adding loose fiber part be joined together, creating an effective län Re tear length is obtained. Also, the product does not dust more. Other natural binders are proteins, alginates and casein.

In the process according to the invention, the water-soluble Copper phthalocyanine complex together with the to be treated Substances (a), (b) and / or (c) and optionally further Components mixed with water to form an aqueous suspension, wherein the pH of the suspension in the oxidative bleaching is set to about 7.0 to 11. Preferably takes place an intensive mixing of the ingredients by taking longer as half an hour, especially about 1 to 4 hours, intensive mixes. Preferably, at a temperature of about 10 to 90 ° C, especially at about 20 to 85 ° C, mixed intensively.

The proportion of copper phthalocyanine complex is about 0.0005 to 0.1 wt .-%, based on the weight of the behan substances (a), (b) and / or (c).

In addition to the copper-phthalocyanine complex can also optical Brightener can be used which does not activate the acid fabric effect. Examples of optical brighteners are Deri vate of Diamino-stilbenedisulfonic acid and / or Diphenylbisty ryl compounds. In the combination of photoactivators with the optical brighteners occur particularly advantageous synergistic effects on.  

The copper phthalocyanine complexes used in the invention can be used in oxidative or reductive bleaching become.

The oxidative bleaching is generally hydrogenated peroxide, ozone and / or oxygen. At the oxi Dative bleaching with peroxide does not cause decomposition of the product Peroxide, as in the presence of free heavy metal ions, there the copper ions are firmly bound in the phthalocyanine complex.

The inorganic coloring components are mostly reductive, bleached. In general, it is the goal, available three to convert valuable iron into divalent and that, in dissolved form, as completely as possible to remove. Otherwise it would re-whiten by re-oxidation in air and worsen again.

The reductive bleaching is often done with sodium and zinc di thionite carried out. The thus dissolved bivalent Iron then needs to be complexed to make it in solution remains, or the non-removable portion must be before the return oxidation are protected. Usually these are phospha te, fluorides or complexing agents, such as EDTA used. A Another method is based on the removal of the dissolved two valent iron ions by means of ion exchangers. Also in one reductive system to be bleached is still residual oxygen handen. This residual oxygen is activated and can enter the This form no longer with the reductive acting bleach (eg, dithionite or hydrosulfite), so that the Ver consumption of bleach can be reduced.

A further advantage is the catalytic process of Verfah rens, wherein the copper phthalocyanine complex by its Ver stay with the fibers, a renewed yellowing verhin changed. So it makes sense synonymous, the photoactivators with kon to combine conventional bleaching process. The photo acti  vators can do this before, during or after the conventional len bleaching be added. For practical reasons Bleaching agent and photoactivator are preferred applied simultaneously.

The copper phthalocyanine complexes used in the invention may optionally in the presence of other adjuncts, such as surfactants, e.g. As dodecyl sulfate, complexing agents, eg. B. Phos phaten and fillers, eg. As zeolites, and binders, such as Latex, acrylic acid or styrene polymers or their copolymers; Auxiliaries, such as polyethylene glycol or glycol ethers be used.

The invention further relates to the above be described in mixtures of copper Phthalocyanine complexes and (a) fibrous materials, (b) fillers or pigments and / or (c) binders for paper origin positioning and finishing (painting of paper).

The mixtures according to the invention are preferably used in the Pulp or paper industry used.

The water-soluble copper phtha used in the invention Locyanin complexes are commercially available with different ionogens (cationic or anionic), different amounts of copper stop and different concentration available.

An anionic copper phthalocyanine complex example, under the name "Carta turquoise FBLN" by the company Clariant (Germany) GmbH sold. It contains no halogens; its copper content is 1.7%. Another anionic copper-phthalocyanine complex is sold under the name "Direct Blue 307" with 0.5 to 3.0 SO ₃ H groups per molecule.

A cationic copper-phthalocyanine complex is used under the Name Fastusol®C from BASF, Ludwigshafen distributed. Its copper content is 1.3%. An anionic Copper phthalocyanine complex is named "Pontamine" ® Brilliant Blue A liquid from Bayer, Leverkusen, distributed: It contains 1.0% Cu; its pH is 10.0 to 12.0.

The following examples illustrate the invention without them up to limit. The percentages refer to Unless otherwise stated, on the weight (otro).

example 1 Oxidative groundwood bleaching

Wood pulp became from the production of a paper factory taken from the LWC (Light Weight Coated) paper manufactures.

50 g (otro) groundwood are treated at 25% consistency and at a temperature of 70 ° C over a period of 90 min. oxidatively bleached, being added at the beginning of the mixing by means of an HC mixer 0.2% NaOH and 0.5% water glass. As further components, 0.1% diethylenetriamine pentaacetic acid (DTPA) as a complexing agent and 3 ppm Photoakti vator added, namely

• 1. cationic copper-phthalocyanine complex of the formula (II), (Fastusol® C)
• 2. anionic copper-phthalocyanine complex of the formula (I), (Carta turquoise)  
• 3. cationic copper-phthalocyanine complex (1) + polyethyl lenglycol (PEG; MW 4000) as wetting agent
• 4. anionic copper phthalocyanine complex (2) + wetting agent as in (3.).
• 5. Aluminum phthalocyanine complex according to EP 0 588 767 B1 Example 1, as a comparison.

After a short exposure time of 5 min. becomes 1% hydrogen peroxide added and mixed.

From the suspensions after dilution to 6 liters at Rapid-Köthen-Blattbildner made paper sheets and after drying (7 min at 95 ° C) the whiteness (R 457 in Anleh to DIN 53245, part 1 + 2) and the brightness with a Ge which meets the requirements of DIN 53145 Part 1, be true (R457).

The results are given in Table I.  

Table I

Wooden ship oxidatively bleached

From Table I shows that in particular the erfindungsge cationic photoactivator may cause a significant increase in Whiteness and brightness shows.  

Example 2 Reductive groundwood bleaching

The wood pulp became from the production of a paper factory taken from the coated and uncoated papers ago provides.

The groundwood is at 4.3 wt .-% consistency at a Tem temperature of 70 ° C for 60 minutes. bleached reductively. As bleaching reagents are 1.0 wt .-% sodium diothionite and 3 ppm photoactivator (1) and (5) of Example 1 under light Stirring added.

From the suspension as in Example 1 sheets of paper in which, as in Example 1, the degree of whiteness and the brightness can be checked. Furthermore, the L value, as well as the a value and the b value (color locus) determined.

The results are given in Table II.  

Table II

Wood pulp, reductively bleached

From Table II shows that in particular the erfindungsge moderate cationic activator a significant increase in the whiteness of the brightness and L values.  

Example 3 Oxidative waste paper bleach

It becomes waste paper fabric (Deinkingware) from the current Pro production of a paper mill, and the ratio of fiber fabric to water is chosen so that a consistency of 30 wt .-% is obtained. By means of a high consistency mixer the bleaching reagents are mixed, followed by at 70 ° C over a period of 60 min. bleached. As a bleaching reagent are 0.2 wt .-% NaOH, 0.55 wt .-% sodium water glass and then 3 ppm of Photoactivators (2) to (5) of Example 1 added. Finally, 1.2 wt .-% hydrogen per oxide added.

From the suspension as in Example 1 sheets of paper in which, as in Example 1, the whiteness, the Brightness and the L, a and b values are determined.

The results are given in Table III.  

Table III

Waste paper, oxidatively bleached

From Table III shows that in particular the Cationic activator according to the invention a significant increase of whiteness and brightness.  

Example 4 Bleaching a paper filler (kaolin)

The filler kaolin comes from a mining area with strong organic contaminants (humic acids) that are oxidative are bleachable.

500 g of kaolin are dissolved in 1000 ml of water at a temperature of 25 ° C over a period of 45 min. while stirring sus to obtain a solids content of 50% by weight becomes. Then, a pH of 8 by addition of NaOH set. It will take 5 min. further stirred, whereupon 0.5% by weight Zeolite and in each case 3 ppm of photoactivator (2), (3) and (5) of Example 1 are added. Further, 3 ppm each Photoactivator (2) of Example 1 with 0.5% zeolite (2Z) and 0.3 ppm photoactivator (5) of Example 1 at 0.5% by weight. Zeolite (5Z) added.

The suspensions are shaken vigorously (supply of me chanischer energy) with a dispersing 1 hr. At 25 ° C stirred.

Then the suspensions are filtered off and the residue is in the drying oven with circulating air at 70 ° C to the weight Constance dried, then ground and the whiteness in Anleh tion to DIN 53245, part 1 + 2 determined. This will be on one Glass plate a measuring tablet at a measuring pressure of 120 kPa made for 10 sec. The determination of the reflection facet The doors (R 457) are made on the surface during pressing with the glass plate in contact, with a device that meets the requirements of DIN 53145, Part 1. The results are given in Table IV.  

Table IV Bleaching of kaolin with photoactivators

photo-activator Whiteness R457 without 76.9 2 79.4 2Z 80.3 4 80.2 5 78.4 5Z 79.6

From Table IV shows that in particular the samples 2Z and 4 show a significant increase in whiteness.  

Example 5 coating tests

Coating experiments with and without copper-phthalocyanine complex are carried out on a test coater with a 54 g / m ² roll paper. The photoactivator (Sample No. 2 of Example 1) is added in each case in the coating color preparation. The coating color recipe is given in Table V.

Table V

The coating colors are produced as follows:
After the water has been added, the pigments (carbonate types and kaolin) are added. Next, the binders and the optical brighteners and, lastly, the photoactivator are added.

The coated paper is dried as follows:
First infrared drying, then Airfoil (air blow box) with air temperature of about 100 to 120 ° C.

The whiteness and the brightness become as in Example 1 certainly. The results are given in Table VI.

Table VI

Table VI shows that with the Photoakti invention vatoren coated paper with respect to whiteness and Hel was superior to the comparison products.  

Example 6 Bleaching of native corn starch

The corn starch used is a commercial common product for use in the mass or in the stroke of Papers. 50 g of starch are spread on a flat surface and there are 3 ppm photoactivator (2) to (4) of Example 1 added by spray application in strong dilution, whereupon the starch is dried in air for about 3 days. The on closing evaluation was carried out analogously to Example 4. The Er results are given in Table VII.  

Table VII

Whiteness and brightness development of native corn starch

Table VII shows significant whiteness and brightness increase in the corn starch treated according to the invention.

Claims (14)

1. A method for improving the whiteness, brightness and chromaticity of (a) fibrous materials, of (b) inorganic fillers and pigments, and of (c) binders for paper making and finishing, wherein the substances to be treated (a), (b) and / or (c) at least one water-soluble phthalocyanine photoactivator is added, characterized in that the water-soluble phthalocyanine photoactivator used is a water-soluble copper phthalocyanine complex. 2. The method according to claim 1, characterized in that at least one water-soluble copper-phthalocyanine complex of the formula
in which CuPc is the copper phthalocyanine ring system, Y is hydrogen, an alkali metal or ammonium, v is 1 to 5, R is fluorine, chlorine, bromine or iodine and x is 0 to 8. 3. The method according to claim 2, characterized in that one uses a copper-phthalocyanine complex of the formula (I), where Y is hydrogen, potassium or sodium, v 2 to 4, R is chlorine or bromine and x is 0 to 2. 4. The method according to claim 1, characterized in that at least one water-soluble cationic copper phthalocyanine complex of the general formula
wherein CuPc the copper phthalocyanine ring system, R is fluorine, chlorine, bromine or iodine, x 0 to 8, R ₁ , R ₂ , and R ₃ independently of each other alkyl groups having 1 to 18 carbon atoms or aryl, aralkyl or Alkaryl groups, n is 1 to 18 and y is 1 to 5. 5. The method according to claim 4, characterized in that one uses a copper-phthalocyanine complex of the formula (II), wherein at least one of the groups R ₁ , R ₂ and R _{3 is} a lower alkyl group having 1 to 5 carbon atoms. 6. The method according to any one of claims 1 to 5, characterized gekenn characterized in that as pulps (a) wood pulp, pulp, Waste paper, textile, pulp derivatives or their mixtures used. 7. The method according to any one of claims 1 to 4, characterized marked characterized in that as fillers or pigments (a) aluminum silicates, magnesium silicates, aluminum / magnesium mixed spirits cate, calcium carbonate, calcium sulfate, titanium dioxide or their Mixtures used. 8. The method according to any one of claims 1 to 6, characterized gekenn records that the copper phthalocyanine complex together with the substances to be treated (a), (b) and / or (c) and ge if necessary, further components with water to an aqueous Suspension is mixed.   9. The method according to any one of claim 8, characterized gekennzeich net, that at about 10 to 90 ° C, in particular at about 20 mixed intensively up to 85 ° C. 10. The method according to any one of claims 1 to 9, characterized gekenn records that the proportion of the copper phthalocyanine complex at about 0.0005 to 0.1% by weight of the weight lying substances (a), (b) and / or (c). 11. The method according to any one of claims 1 to 10, characterized ge indicates that, as additional photoactivators, eosin, Rose Bengal, fluorescein, chlorophyll, phorphyrin compounds, Methylene blue or mixtures thereof used. 12. The method according to any one of claims 1 to 11, characterized ge indicates that the copper-phthalocyanine complex in the oxidative or reductive bleaching. 13. The Mi produced according to one of claims 1 to 12 mixtures of water-soluble copper-phthalocyanine complexes and (a) fibrous materials, (b) fillers or pigments and / or (c) binders for papermaking and finishing. 14. Use of the mixtures of claim 13 in the cell pulp or paper industry.